Identical Size Research Articles

Structural transitions in TPGS micelles induced by trehalose as a model cryoprotectant

Cryoprotectants are included to protect colloidal dispersions from mechanical stress of ice crystals formed at sub-zero temperature. Trehalose (THL) remains a popular choice among sugar-based cryoprotectants. In the present study, we illustrate the effect of THL concentration (0.01–1 M) upon microstructural characteristics of nonionic micelles which were formulated with alpha tocopherol polyethylene glycol 1000 succinate (TPGS). The effect of THL incorporation in drug-loaded micelles was studied by using capsaicin (CAP), a hydrophobic alkaloid. Our interpretations are based on the results of cloud point, dynamic light scattering (DLS), small angle neutron scattering (SANS), nuclear magnetic resonance (NMR) and Fourier-transformed infrared (FTIR) spectroscopic measurements. Cloud point and spectral data reveal that the micelles underwent progressive dehydration at increasing THL concentration. Together with scattering data, it is discernible that THL molecules intercalated in the micelle corona and expelled water from the polar headgroups. In spite of this, micelle size did not change until 1 M THL. Freeze-thawed micelles also displayed identical size distribution. Structural transitions occurred upon solubilization of CAP; micelles changed from sphere to ellipsoids. We suggest that CAP molecules occupied the hydrophobic core and triggered the formation of ellipsoids which were retained in the presence of THL. These observations lead us to a conclusion that, by virtue of its selective action (removal of freezable water) in headgroup region, THL protects the morphology of micelles over a wide concentration range.

부배열 TRM이 적용된 능동위상배열 안테나의 Field of View 분석

In this paper, we describe a field of view (FOV) analysis of active phased array antennas with transmitter and receiver modules (TRM) applied to each subarray stage. First, the subarray design and amplitude-tapering optimization methods are introduced. Second, a comparative analysis of the sidelobe level (SLL) and half-power beamwidth (HPBW) according to the change in the distance between the radiation elements and number of subarrays is presented. Finally, the beam characteristics according to the change in the distance between the radiation elements are analyzed under the condition of identical aperture size and number of subarrays. The beam steering angles were analyzed for boresights at 7°, 12°, and 15°. As the number of subarrays increased and the distance between the radiation elements narrowed, a lower SLL was secured during beam steering. It was confirmed that the distance between phase centers between the subarrays was dominant in the phased array antenna with subarrays.

Natural variability and potential use of melanomacrophage centres as indicators of pollution in fish species from the NW Mediterranean Sea

The present study provides a baseline assessment of the prevalence and densities of splenic melanomacrophage centres (MMCs) in 18 fish species from the NW Mediterranean Sea related to spatiotemporal and environmental factors and fish traits. Their correlation with other established health indicators, such as body condition indices (condition factor, hepatosomatic and gonadosomatic indices), parasite community descriptors and histological assessment of target organs (gills, liver and spleen) is also assessed. Despite MMCs variability is mainly attributed to the species identity and fish size, their potential use as generic biomarkers of health condition is pointed out for certain species (e.g. Spicara maena and Micromesistius poutassou) in which an increased response was identified, and whose potential drivers are discussed. Most importantly, present results provide a comprehensive assessment of MMCs in the fish community for future studies in the area.

Tile-based massively scalable MIMO and phased arrays for 5G/B5G-enabled smart skins and reconfigurable intelligent surfaces

This work presents a novel tile based approach to constructing, in a modular fashion, massively scalable MIMO and phased arrays for 5G/B5G millimeter-wave smart skins and large-area reconfigurable intelligent surfaces for Smart Cities and IoT applications. A proof-of-concept 29 GHz 32 elements phased array utilizing 2 times 2 “8-element subarray” tiles was fabricated and measured and demonstrates +/- 30beamsteering capability. The unique benefits of the proposed tile approach utilizes the fact that tiles of identical sizes can be manufactured in large quantities rather than have arrays of multiple sizes serve various user capacity coverage areas. It has to be stressed that the proof-of-concept flexible 2 times 2 tile array features no performance degradation when it is wrapped around a 3.5 cm radius curvature. This topology can be easily scaled up to massively large arrays by simply adding more tiles and extending the feeding network on the mounting tiling layer. The tiles are assembled onto a single flexible substrate which interconnects the RF, DC and digital traces, allowing for the easy realization of on-demand very large antenna arrays on virtually any practical conformal platform for frequencies up to sub-THz frequency range.

Molecular characterization of the phytopathogen C. theae (Petch) – Causative of birds eye spot infection in Camellia sinensis host through DNA polymorphism and proteome analysis

The pathogenic fungus Cercospora infecting plants causes high degree symptomatic disease in several important crops including tea (Camellia sinensis). Genetic diversity studies on plant pathogens are essential to tackle plant diseases, hence in the proposed study, Cercospora theae isolated from different regions was characterized using the molecular tool like RFLP of the rDNA regions amplified using ITS primers. Protein profiling for all the isolates was also done by optimizing the protein extraction using sodium dodecyl sulphate (SDS), urea and Trichloroacetic acid (TCA) protocols. Genetic relatedness with the identical size of molecular weight among the three C. theae isolates of different regions was studied from the 5.8S rDNA-ITS amplified regions. Digestion of the amplified regions with seven specific endonucleases exposed the same banding pattern among the isolates. The sequence data from the three isolates showed maximum homology with the Genbank sequence of Cercospora spp. (HQ450006, JQ754039, JQ753964, JN942274, JN942272, FJ460222 and EU581822). Further, an optimized protocol for protein profiling of C. theae was determined to extract the majority of the proteins. The results also revealed that the most suitable protocol for studying the proteomics of C. theae was the SDS extraction method.

Asymmetric Microelectrodes for Nanoliter Bubble Generation via Electrolysis

Microfabricated devices for gas bubble generation via water electrolysis typically employ two electrodes of identical size (i.e. interdigitated electrodes or microelectrode pairs). Contrary to this practice, asymmetrically sized electrode pairs offer distinct advantages in the formation of single, trapped nanoliter-volume gas bubbles in microfluidic devices. Although such principles may apply generally to MEMS or micro-scale water electrolysis devices, our model system consisted of a Parylene C microfluidic structure to contain the bubble and embedded thin-film Pt electrodes immersed in 1x phosphate buffered saline solution. The geometric area of one microelectrode was constant (working electrode) while that of the second electrode (counter electrode) was varied over five orders of magnitude. Although increased counter electrode size increases overall device size, it provides improvements in various performance metrics. The largest tested counter electrode size resulted in 41% energy savings per bubble, improved bubble volume uniformity, enabled successful discrimination between O₂ versus H₂ gas generation, and achieved bubble stability exceeding 500 minutes (a 25x improvement over previous work). The underlying theory motivating the use of asymmetric electrodes is detailed and followed by experimental demonstration. Finally, a discussion on tradeoffs to assist in the design of MEMS-based electrolytic bubble generation devices is provided. [2021-0172]

Extracting microplastic decay rates from field data

Being able to estimate and predict future microplastic distributions in the environment is one of the major challenges of the rapidly developing field of microplastic research. However, this task can only be achieved if our understanding of the decay of individual microplastic particles is significantly enhanced. Here, we show by using a rate equation model that currently available data of size distributions measured at single times cannot provide useful insights into this process. To analyze what data contains more information we generated more complex artificial data mimicking subsequent measurements using a stochastic simulation algorithm. Applying our model to this data revealed the following minimal requirements for future experimental data: (1) data should be collected as time series at identical spots and (2) size measurements should be combined with mass measurements. In contrast to currently available data, flux rates and decay parameters of individual particles can be extracted from such data.

Texturing Fermented Emulsion Gels from Soy Protein: Influence of the Emulsifying Agent-Soy Protein vs. Pectin Microgels-On Gel Microstructure, Rheology and Tribology.

Soy-based yoghurt alternatives are nowadays preferred by consumers. However, they are often perceived as too firm or too soft, sandy, or fibrous. In order to improve this, fibres, especially as in form of microgel particles (MGP), and fats are added to the soy matrix to create a creamy mouthfeel. Both fat and pectin-based MGP can interact with each other and with the protein matrix, creating different microstructures. This can influence the rheological and tribological properties of plant-based protein gels. This works focuses on the effect droplet stabilisation (coconut oil) on the rheological and tribological behaviour of the fermented stirred soy protein gels. For this, fat droplets were stabilised with MGP, SPI, or a mixture of both. Whilst the rheological behaviour remained unchanged for all investigated samples, the tribology of the samples depended on the emulsifier used. The addition of fat decreased the traction coefficient compared to the reference samples without fat. Even though all samples had the same fat content and identical droplet sizes, differences were observed in their lubricating properties. Droplets stabilised solely with SPI presented the best lubricating properties, as indicated by the lowest traction coefficient. Samples stabilised with MGP (or in mixture with SPI) caused higher friction.

Role of Counterions in the Adsorption and Micellization Behavior of 1:1 Ionic Surfactants at Fluid Interfaces─Demonstrated by the Standard Amphiphile System of Alkali Perfluoro-n-octanoates.

In our latest communication, we proved experimentally that the ionic surfactant’s surface excess is exclusively determined by the size of the hydrated counterion.[Lunkenheimer, Langmuir,2017, 33, 10216−1022410.1021/acs.langmuir.7b00786]28925711. However, at this stage of research, we were unable to decide whether this does only hold for the two or three lightest ions of lithium, sodium, and potassium, respectively. Alternatively, we could also consider the surface excess of the heavier hydrated alkali ions of potassium, rubidium, and cesium, having practically identical ion size, as being determined by the cross-sectional area of the related anionic extended chain residue. The latter assumption has represented state of art. Searching for reliable experimental results on the effect of the heavier counterions on the boundary layer, we have extended investigations to the amphiphiles’ solutions of concentrations above the critical concentration of micelle formation (cmc).We provided evidence that the super-micellar solutions’ equilibrium surface tension will remain constant provided the required conditions are followed. The related σcmc-value represents a parameter characteristic of the ionic surfactant’s adsorption and micellization behavior. Evaluating the amphiphile’s surface excess obtained from adsorption as a function of the related amphiphile’s σcmc-value enables you to calculate the radius of the hydrated counterion valid in sub- and super-micellar solution likewise. The σcmc-value is directly proportional to the counterion’s diameter concerned. Taking additionally into account the radii of naked ions known from crystal research, we succeeded in exactly discriminating the hydrated alkali ions’ size from each other. There is a distinct sequence of hydration radii in absolute scale following the inequality, Li+ > Na+ > K+ > (NH4)+ > Rb+ > Cs+. Therefore, we have to extend our model of counterion effectiveness put forward in our previous communication. It represents a general principle of the counterion effect.

The surface coating of iron oxide nanoparticles drives their intracellular trafficking and degradation in endolysosomes differently depending on the cell type

Magnetic nanoparticles (MNPs) are potential theranostic tools that are biodegraded through different endocytic pathways. However, little is known about the endolysosomal network through which MNPs transit and the influence of the surface coating in this process. Here, we studied the intracellular transit of two MNPs with identical iron oxide core size but with two distinct coatings: 3-aminopropyl-trietoxysilane (APS) and dimercaptosuccinic acid (DMSA). Using endolysosomal markers and a high throughput analysis of the associated proteome, we tracked the MNPs intracellularly in two different mouse cell lines, RAW264.7 (macrophages) and Pan02 (tumor cells). We did not detect differences in the MNP trafficking kinetics nor in the MNP-containing endolysosome phenotype in Pan02 cells. Nonetheless, DMSA-MNPs transited at slower rate than APS-MNPs in macrophages as measured by MNP accumulation in Rab7+ endolysosomes. Macrophage DMSA-MNP-containing endolysosomes had a higher percentage of lytic enzymes and catalytic proteins than their APS-MNP counterparts, concomitantly with a V-type ATPase enrichment, suggesting an acidic nature. Consequently, more autophagic vesicles are induced by DMSA-MNPs in macrophages, enhancing the expression of iron metabolism-related genes and proteins. Therefore, unlike Pan02 cells, the MNP coating appears to influence the intracellular trafficking rate and the endolysosome nature in macrophages. These results highlight how the MNP coating can determine the nanoparticle intracellular fate and biodegradation in a cell-type bias.

Permeability of polydisperse solid foams.

The effect of polydispersity on foam permeability is investigated by numerical simulations. Foam structures are first generated by Laguerre tessellations via the Neper software and relaxed to minimize the surface energy via the Surface Evolver software. The fluid flow and permeability are then calculated by means of pore-network simulations, by considering either fully open-cell foams or foams with randomly selected closed windows. Different configurations of window aperture are used, including identical window aperture size, identical window aperture ratio, or random window aperture ratio. The main results are obtained for the case of foams having identical and uniform window aperture ratios. For such foams and at constant mean pore size, foam permeability is found to strongly increase with the polydispersity degree. The numerical results are employed to discuss the validity of the mean pressure field assumption used to calculate the foam permeability, the effect of small pores, and the definition of an equivalent Kelvin foam size. We show that as long as the fluctuations of the window aperture ratio remain low, foam permeability can be estimated by using the mean pressure field hypothesis. The weak effect of small pores on permeability is related to their small contribution to the overall fluid volume fraction. Finally, various estimations of the equivalent Kelvin foam size based on pore-size distribution are proposed.

Judith, Salome, and Allegories of Tyranny in the Work of Lucas Cranach the Elder

AMONG THE MOST ENIGMATIC compositions in Lucas Cranach’s oeuvre are his biblical decapitations of the 1530s. In 1531, he executed a pair of panels depicting the story of Judith and Holofernes; between 1531 and 1539, he and his workshop produced four paintings of the Feast of Herod of nearly identical composition and size. Through the decade, Cranach and his shop painted half- to full-length images of the princess Salome alone that are almost indistinguishable from his contemporaneous paintings of Judith. I propose that Cranach’s narrative paintings should be understood as allegories: they were veiled references to the tyranny of the imperial court and were intended for the Lutheran prince-electors in the years following the Diet of Augsburg. These half-length images of Judith and Salome proliferated because both subjects connoted the downfall of tyrannical forces. Cranach thus skillfully adapted rarefied political iconography to imagery that served a broad Reformation audience.

Predicting spatial and seasonal patterns of wildlife–vehicle collisions in high-risk areas

Context Vehicle collisions with wildlife can injure or kill animals, threaten human safety, and threaten the viability of rare species. This has led to a focus in road-ecology research on identifying the key predictors of ‘road-kill’ risk, with the goal of guiding management to mitigate its impact. However, because of the complex and context-dependent nature of the causes of risk exposure, modelling road-kill data in ways that yield consistent recommendations has proven challenging. Aim Here we used a multi-model machine-learning approach to identify the spatio-temporal predictors, such as traffic volume, road shape, surrounding vegetation and distance to human settlements, associated with road-kill risk. Methods We collected data on the location, identity and wildlife body size of each road mortality across four seasons along eight roads in southern Tasmania, a ‘road-kill hotspot’ of management concern. We focused on three large-bodied and frequently affected crepuscular Australian marsupial herbivore species, the rufous-bellied pademelon (Thylogale billardierii), Bennett’s wallaby (Macropus rufogriseus) and the bare-nosed wombat (Vombatus ursinus). We fit the point-location data using ‘lasso-regularisation’ of a logistic generalised linear model (LL-GLM) and out-of-bag optimisation of a decision-tree-based ‘random forests’ (RF) algorithm for optimised predictions. Results The RF model, with high-level feature interactions, yielded superior out-of-sample prediction results to the linear additive model, with a RF classification accuracy of 84.8% for the 871 road-kill observations and a true skill statistic of 0.708, compared with 61.2% and 0.205 for the LL-GLM. The lasso rejected road visibility and human density, ranking roadside vegetation type and presence of barrier fencing as the most influential predictors of road-kill locality. Conclusions Forested areas with no roadside barrier fence along curved sections of road posed the highest risk to animals. Seasonally, the frequency of wildlife–vehicle collisions increased notably for females during oestrus, when they were more dispersive and so had a higher encounter rate with roads. Implications These findings illustrate the value of using a combination of attributive and predictive modelling using machine learning to rank and interpret a complexity of possible predictors of road-kill risk, as well as offering a guide to practical management interventions that can mitigate road-related hazards.

Comparison study of structural thermostability of SiO2 supported Au@Pt and Au@Pd core-shell nanoparticles

Bimetallic nanoparticle (NP) catalysts have attracted long-standing attentions for their wide applications in a broad range of chemical reactions. Their catalytic performance tightly relies on the structure of bimetallic NPs. Atomiclevel understanding of their structural thermostability is of great importance for developing advanced bimetallic catalysts with high stability. Here we precisely fabricated Au@Ptand Au@Pd core-shell catalysts on a SiO2 support with an identical Au core size of ∼5.1 nm and a similar shell thickness of ∼2 monolayers via selective atomic layer deposition. Spectroscopic characterizations were employed to compare their structural thermostability at elevated temperatures in a hydrogen reducing atmosphere. We revealed that the Au@Pt/SiO2 core-shell catalyst exhibited a considerably higher structural thermostability against atom inter-diffusion to alloys than that of Au@Pd/SiO2. Meanwhile, these two catalysts both preserved the particle size without any visible aggregation even after reduction at 550°C. Higher structural thermostability of Au@Pt/SiO2 core-shell catalyst might mainly stem from the distinctly higher melting point of Pt shell and their relatively smaller Au-Pt lattice mismatch. Such direct comparison of the structural thermostability of two different core-shell catalysts but with identical structures provides a valuable insight into the nature of thermodynamic behavior of bimetallic NPs at elevated temperatures.

Synthesis and characterization of organic ligand capped luminescent silicon nanoparticles

The confinement effects on the optical characteristics of silicon nanoparticles (Si-NPs) are very attractive for a variety of low-cost applications of this nontoxic material in light emitting devices and photovoltaics. However, effective utilization of these properties in devices have been limited as chemically prepared Si-NPs are highly prone towards oxidation to form amorphous silica. Surface modified luminescent Si-NPs are synthesized by an inexpensive wet-chemical solution-based route by hydrolyzing the silicon tetrachloride (SiCl4) and terminating the Si dangling bonds by using different capping ligands. Structural, optical and electrical properties are studied and the photoluminescence (PL) characteristics are correlated to its core–shell structure. The photoluminescence characteristics of the surface modified Si-NPs of virtually identical sizes in the core was accounted in terms of effects from the variations in the cell-structure on the surface of Si-NPs introduced by changes in the nature of siloxane capping.

Mechanical strength and water penetration depth of palmyra fibre reinforced concrete

Natural fibre reinforced composites are replacing the conventional fibre reinforced composites for several applications due to natural fibre availability, variety and lesser raw material cost. Using natural fibres in composites also reduces the issue of agricultural residue disposals, which are in abundance. Different natural fibres exhibit unique properties when it is used in composites and hence there is a need to study the behaviour of scarcely used natural fibres. Indian palmyra trees (Borassus flabellifer) are fast growing commonly found trees in Southern India. From the base of these palm tree leaves, palmyra fibres are taken out. Though these fibres are locally available in huge quantities, these are very rarely used as reinforcing material in concrete compared to other natural fibres like coir, sisal, jute etc. Palmyra fibre reinforced cement composite specimens were prepared by varying the fibre content (0.5%, 1% and 2% by weight of cement) and length of fibre (25 mm and 50 mm). Plain concrete and palmyra fibre reinforced concrete specimens of identical size were tested for mechanical strength and also for its depth of water penetration. The work carried out revealed that the water penetration of palmyra fibre reinforced concrete increased with fibre content increase. The compressive strength of palmyra fibre reinforced concrete improved up to 1% of fibre content and further increase in fibre content upto 2% resulted in compressive strength reduction for both the fibre lengths. However, split tensile strength, flexure strength and shear strength increased with fibre content increase in the mix. Based on the mechanical strength properties investigated, increase in shear strength was found to be more significant with the inclusion of palmyra fibres in concrete.

Experimental study on torsional behavior of thin- and thick-walled RC box-girders using BFRP bars and steel stirrups under combined torsion-shear-moment

Experiments on hollow FRP-RC members subjected to combined torsion are uncommon. Six specimens of identical size and length, five rectangular and one trapezoidal, were constructed and tested in this investigation. About 2.5 percent reinforcement is included in all of the specimens. The study variables were the effect of shape (rectangular vs trapezoidal), concrete wall thickness (thin vs thick), cover thickness, and reinforcement layout (single-layer vs double-layer). Strength and stiffness, deflection and angle of twist, cracking pattern, and modes of failure were all evaluated. It is discovered that a trapezoidal thin-walled box-girder can attain around 85% of the ultimate strength of its rectangular counterpart, with 9% less deflection and 11% more twist. Thin-walled box-girders have a 17 percent higher ultimate torsional capacity than thick-walled members with thick covers. Thin-walled box-girders have the least deflection and twist, but their ultimate torsional capacity is limited compared to thick-walled counterparts. In thick-walled members, utilizing a double layer of reinforcement instead of a single-layer, can result in just a 4% increase in ultimate strengths, while deflection and twist both drop by 23%; in addition, a double-layer reinforced box-girder with thicker webs than flanges can reach the largest ultimate strength with the least angle of twist at failure.

Experimental investigation of the solar distiller using nano-black paint for different water depths

World nations are continuously thriving to find a prompt solution to the scarcity of potable water. In recent years, solar distiller has been suggested as a feasible technology for tapping drinkable water from saline water. In a solar distiller, the absorber surface has a significant impact on the solar distiller's performance. This work presents an attempt to increase the performance of a traditional solar distiller by improving the thermal conductivity of the absorber surface through spraying a nano-black paint over its surface. In this study, two distillers of identical size were used. One solar distiller was made by painting the absorbing plate with normal black paint and labelling it as a traditional solar distiller (TSD). Another distiller was prepared by painting the absorber of the traditional distiller with nano-black paint (TSD-Nano). The tests had been carried out over two days, with water levels of 0.1 cm and 0.2 cm in both solar distillers, respectively. For the fabrication of TSD-Nano, a nano-paint was prepared by thoroughly mixing 1.0 vol% of nano-CuO particles with black paint. The results showed that a coating of nano-black paint increased the thermal conductivity of the absorber and thereby increased the production of the solar distiller by 10.38% and 8.73% for 0.1 cm and 0.2 cm water depths, respectively, comparing to normal black paint.

Mechanoluminescent study for optimization of joint design on cross tension test

ABSTRACT To develop cross tension (CT) tests for adhesive dissimilar material joints, we investigated the design of CT test specimens (particularly the shape of the bonding area) through mechanoluminescence. To clarify the factors that cause high scattering of cross tension strength (CTS) values in the case of conventional CT specimens with square adhesive regions, we visualized the mechanical behavior during the CT test (particularly the fracture progress behavior inside the adhesive layer) by using mechanoluminescence. The mechanoluminescence revealed inconsistent patterns in each CT specimen with a square bonding area. This indicates that the different stress concentration behaviors and crack growth/peeling behavior during the CT test are factors that cause high scattering of CTS values. Meanwhile, in the case of CT specimens with circular adhesive regions, the scattering of CTS values was reduced significantly, and the mechanoluminescent patterns were consistent as circles of almost identical size in all the specimens. It can be considered that mechanoluminescence has the potential to effectively visualize mechanical behavior for optimizing test designs.

The effect of social capital on organizational repertoires of American Protestant missions

A religious organization’s choice of activities is shaped not only by theological goals but also the capital available to it. Prior research has shown how economic and religious capital influence Protestant missionary organizations’ repertoires of activism but has largely ignored the role of social capital. Using the most recent data on transnational American Protestant mission agencies, this study aims to fill this gap. Using a Bourdieuian field approach and multiple correspondence analysis, the study finds that linking and bonding social capital both shape whether an agency generalizes rather than specializes in specific ministry activities. Both bonding and bridging social capital, in turn, prompt a more other-worldly than this-worldly ministry orientation, but this is a pattern most characteristic of Evangelical agencies, suggesting an intersection between religious identity and organizational network size. The study concludes by discussing the implications of these findings for interorganizational collaboration and resource use.