Single-layer Arrangement Research Articles

Investigating micelle formation in systems with benzethonium chloride and n-lauroyl sarcosine sodium salt: The impact of thermal effects and ethyl lactate concentration using volumetric, statistical, acoustic, and molecular dynamic methods

Surface active agents (SAAs) are versatile molecules that possess the ability to serve as multifunctional ingredients in a wide range of consumer products across various industrial sectors. These molecules can act as wetting and dispersion agents, emulsifiers, foaming and anti-foaming agents, lubricants, and more. The objective of this study was to evaluate the effect of temperature, and ethyl lactate concentration on micelle formation in systems containing benzethonium chloride (BC) and N-lauroyl sarcosine sodium salt (NLSS). The experimental measurements were conducted at three equidistant temperatures i.e., 298.15 K to 318.15 K and pressure, P=0.1 MPa. Several volumetric as well as compressibility parameters including apparent molar properties (Vϕ,Kϕ,S), partial molar properties (Vϕ°,Kϕ,S°), transport properties (ΔtrVϕ°,ΔtrKϕ,S°), hydration number, etc. have been evaluated. A Bayesian two-factor design with uninformative priors was used to analyze the values of Vϕ°,and Kϕ,S°. It was possible to determine that the temperature factors, and the ethyl lactate (EL) addition significantly influence the results for Vϕ° while for Kϕ,S°it is not appreciable at 5 and 10 % in EL concentration when BC and NLSS systems is compared. The simulations of the micellization process show the impact of temperature, particularly in the presence of ethyl lactate, is evident in the structural and dynamic changes observed in the micelles. Specifically, as the temperature rises from 298.15 K to 318.15 K, the self-assembly process becomes more spontaneous and accelerated, leading to larger and more spherical micelles. These alterations in micelle size, shape, and orientation enhance their capacity to effectively solubilize hydrophobic substances. The computational simulations demonstrated that BC molecules exhibit spontaneous aggregation at the interface of polar-nonpolar systems, resulting in the formation of a monolayer. In this monolayer, the heads of the molecules are oriented towards the polar phase, while the hydrophobic tails are in the nonpolar phase. Similarly, the NLSS system exhibits a continuous and gradual process of self-organization over a period of 120 ns, where NLSS molecules naturally come together to create a single layer arrangement at the zigzag-shaped boundary.

Single layer dual hollow core antiresonant fiber based polarization beam splitters

To confront the growing challenges of integrated photonics, optical devices need to be compact in size to integrate them in communication networks where a polarization beam splitter device may play a crucial role. In this regard, hollow core antiresonant fibers have garnered significant attention as a versatile platform, for achieving efficient polarization splitting, owing to their promising characteristics. In this article, traditional and available multilayer complex cladding geometry, in dual hollow core antiresonant fiber, is simplified to single layer arrangement and created efficient polarization beam splitters device. First, we introduced a splitter with single layer cladding geometry that simultaneously presents a short device length of 2.24 cm and an ultra-wide bandwidth of 415 nm, with an extinction ratio exceeding 20 dB. This bandwidth also encompasses widely used communication wavelengths of 1.31μm and 1.55μm. Moreover, a careful investigation of geometrical dimensions, nesting, and conjoined tubes inclusion suggests that the device structure having two horizontal nested elements has an excellent splitting performance with a concise splitter length of 2.06 cm and an ultra-wide bandwidth of 465 nm, covering most telecom bands. Notably, the splitters have the highest extinction ratio of around 140 dB at 1.55μm, along with an effective single mode performance. Therefore, the claimed single layer polarization splitters might be an attractive candidate for the integration of optical devices in communication systems.

Аналіз одношарового руху зернового матеріалу у вертикальному пневмосепараційному каналі

The separation of grain and light impurities in a vertical pneumatic separation channel with an increase in its capacity occurs under rather difficult conditions, since the thickness of the grain flow increases, which leads to a redistribution of particles of grain material and reduces the probability of passing light impurities through the grain layers and their release into the sedimentation chamber. To increase the productivity of vertical pneumatic separation channels, it is necessary to create conditions for single-layer placement of grain material in the separation zone at a distance that excludes the interaction of other layers of grain input. This will allow the majority of grain particles to be in the same conditions and increase the percentage of probability of separation into the sedimentation chamber to the maximum value. Therefore, a theoretical flow analysis aimed at studying the interaction of grain mixture particles with the air flow, taking into account the single-layer arrangement of several grain layers and the contamination of the air flow with light impurities in the separation zone, is a rather important task. Theoretical dependences have been obtained that allow substantiating the main parameters of the pneumatic separation channel and determine the residence time of a grain particle in the separation zone, taking into account the clogging of the air flow. For a grain material of mass characterized by the values of the windage coefficient kз = 0.075...0.12 for full grain, kз = 0.11...0.14 for substandard grain, and kз = 0.125...0.55 for light impurities, it is possible to clearly separate the grain mixture into fractions by setting the appropriate parameters and operating modes of the pneumatic separation channel under the condition of a single-layer multilevel input. Due to the selection of rational parameters of the feeding devices for delivering the material into the separation zone and establishment of appropriate aerodynamic modes of air flow, it is possible to separate up to 96% of light impurities from the grain material, while ensuring minimal losses of full grain to waste.

Investigation on the Mechanical Properties of Coconut Leaf Stalk Fibres Reinforced Composites

ABSTRACT The use of coconut leaf stalk fibers in composites has rarely been investigated. This study focuses on the use of Malayan Dwarf coconut leaf stalk fibers as reinforcement in a polyester matrix. After extracting the fibers, the optimum concentration of sodium hydroxide for their mercerization was determined. This was, firstly, done through tensile, contact angle, FTIR, and SEM tests. They were supplemented by preliminary tensile tests which were performed on composites, with 0.5% fiber content (by weight). The selection of the optimum mercerization process led to the production of the composites for further investigations. Two types of plain weave arrangement (single layer and multiple layers) of the fiber reinforcements were considered, with increasing fiber loading. For the mercerization process, 5% sodium hydroxide treatment was found to produce composites with better mechanical properties. The composite, with the single layer arrangement and 1.5% fiber loading, was found to have the highest tensile (46 MPa) and flexural (149 MPa) strength. Two-way ANOVA was used to confirm that the means of the strengths, of the various types of composites tested were not the same. The results of this study are expected to lead to a more sustainable use of waste coconut leaves.

Study on mechanical behavior of steel-UHPC-NC composite beams under negative bending moment

To investigate the negative moment region flexural performance of a steel-ultrahigh performance concrete (UHPC)-normal concrete (NC) composite beam, steel-UHPC-NC composite beams with a uniform and cluster arrangement of studs and three push-out specimens were designed and fabricated. Based on the test results, the finite element model of steel-UHPC-NC composite beams was established and verified. The results of the study show that in the push-out test, the failure mode of the specimens is the shear failure of the stud, and the specimens with the NC-UHPC composite slab and UHPC slab are crushed and spalled at the root of the studs, but the damage extent and damage range of the specimens with UHPC slabs were significantly smaller than the NC-UHPC composite slab specimens. The load-slip response of the push-out specimen is obviously affected by the concrete slab material. The ultimate bearing capacity of the single stud of the steel-UHPC specimen, the steel-UHPC-NC stud single layer arrangement and the double-layer arrangement specimens were 249 kN, 158 kN and 192 kN, respectively. In the negative bending moment zone loading test, the development trend of the mid-span load–displacement curves of steel-UHPC-NC composite beams with uniform and cluster studs is consistent, with the cracks in the former concentrated at the mid-span position and the cracks in the latter concentrated near the nearest group of shear studs in the mid-span. The load–displacement curves of composite beams that studs are evenly distributed and studs are cluster type are consistent, with ultimate displacements in the span of 65.8 mm and 68.5 mm, respectively, and ultimate bearing capacities of 723.8 kN and 712.3 kN, respectively. The calculation results obtained by the simulation method are in good agreement with the test results, which could effectively predict the load–displacement response of the steel-UHPC-NC composite beam.

Sustainable passive cooling strategy for photovoltaic module using burlap fabric-gravity assisted flow: A comparative Energy, exergy, economic, and enviroeconomic analysis

Despite the supremacy of active cooling methods in the thermal management of photovoltaic modules, the passive cooling approach is still prominent due to its simplicity, sustainability, and substantial heat transportation capability. As water siphoning techniques are always promising among multiple passive methods, the present experimental study is focused on energy, exergy, environment, and economic analysis with burlap fabric as a siphoning agent. During haze weather, the day-long testing upholds the burlap single layer arrangement over phase change material-based and evaporative cooling. A maximum 28.6% temperature drop was experienced in burlap based system against the reference module, which narrowed to 15.7% in evaporative cooling and 14.4% in PCM cooling. Even the power enhancement and second law analysis followed the same trend. Later, the best version i.e. burlap based cooling with single and double layers were tested under clear weather, which resulted in a power improvement of 12–15% and 18–21% respectively compared to reference module. Finally, the detailed exergy and economic analysis uphold the sovereignty of the proposed technique.

Simulation Analysis of Power Consumption and Mixing Time of Pseudoplastic Non-Newtonian Fluids with a Propeller Agitator

In order to study the effect of a high twist rate propeller on the flow field characteristics of pseudoplastic non-Newtonian fluids, the numerical simulation method was used to analyze the mixing flow field of pseudoplastic non-Newtonian fluids at different concentrations in this paper. By changing the rotational speed and the blade installation height, the vorticity, turbulent energy, mixing power consumption, mixing time and mixing energy of the flow field were analyzed. By analyzing and comparing the research results, it was found that increasing the mixing propeller speed can effectively improve the mixing effect. Single-layer arrangement of mixing propeller is not suitable to be placed close to the bottom of the tank, and the mixing of the upper flow field is weaker. Under the same conditions, when the viscosity of pseudoplastic non-Newtonian fluid is increased, the high vorticity and high turbulence energy area is reduced to the mixing propeller area, and the time required for mixing 1.25% CMC solution is 246 times longer than that for mixing 0.62% CMC solution and the required mixing energy also increases sharply. The accuracy of the numerical simulation was verified by experiments. Considering the mixing effect and the mixing power consumption, the single-layer arrangement propeller is more suitable for mixing pseudoplastic non-Newtonian fluids with mass fraction of 0.62% CMC or below. This study can provide a reference for the practical application of propeller mixers to mix pseudoplastic non-Newtonian fluids.

Panel gaps are a cost-effective alternative to cool photovoltaic systems

A stepped, multilayer arrangement enhances the efficiency of photovoltaic panels compared to a single-layer arrangement.

Numerical Investigation and Design of Reinforced Concrete Shear Wall Equipped with Tuned Liquid Multiple Columns Dampers

The tuned liquid multiple column damper (TLMCD) is a variation of the tuned liquid column damper (TLCD) that includes multiple vertical columns. A new damping system that embeds TLMCDs within reinforced concrete shear wall systems, termed tuned liquid wall damper (TLWD), is proposed, augmenting the traditional structural component with energy dissipation capabilities. The objective of this study is to assess energy mitigation and strength trade-offs in designing TLWDs and demonstrating the promise of TLWD systems in tall buildings through vertically distributed applications. This is done by investigating the performance of the proposed TLWD through the finite element model (FEM) of a simplified representation of a 42-story building equipped with the multifunctional component. A strength model for the TLWD is developed to empower faster performance evaluation on more complex models. Results from the FEM are used to validate the strength model and show that the model could be used conservatively in assessing strength performance. Design considerations are discussed based on the simplified representation. In particular, to improve mitigation performance while maintaining strength, it is found that a single-layer arrangement of the vertical columns is preferred, while distributing the inertia among a higher number of smaller columns. The proposed TLWD is numerically evaluated on a more realistic system consisting of a multi-degrees-of-freedom representation of the 42-story building under stochastic wind excitation. Simulation results demonstrate that the TLWD, used in a vertically distributed configuration through the building, could be used to mitigate vibrations, outperforming a traditional TLCD system with geometric constraints under 20 design wind realization. Results from the numerical simulations also confirmed the design considerations established through the simplified representation.

Assessment and comparison of different arrangements of horizontal ground heat exchangers for high energy required applications

Horizontal ground heat exchangers (GHEs) have a lower initial installation cost in comparison to vertical ones; however, they require more land area. In order to reduce the required land area of horizontal GHEs, their heat exchange rate per unit land area needs to be enhanced. A remedy to this problem is installing horizontal GHEs in an arrangement with maximum heat exchange rate per unit land area. However, such arrangements have not been introduced for different types of horizontal GHEs thus far. To this end, in this study, the thermal performance of various GHE pipe arrangements for three different types (linear, spiral, and slinky) of horizontal GHEs is evaluated. Comparing the obtained results, the arrangement that provides the maximum heat exchange rate per unit land area for each type is introduced. A 3D numerical model based on the finite-element method is developed to simulate the GHEs performance. In order to have a fair comparison, all studied arrangements are designed to have the same installation cost. The obtained results indicated that the linear GHE with quadruple-layer arrangement provides the most uniform heat distribution in the ground and, therefore, has the highest heat exchange rate per unit land area among all cases studied. This arrangement has about a 34% higher heat exchange rate per unit land area than the conventional single-layer arrangement. The staggered double-layer arrangement is the best arrangement for the slinky and spiral GHE types, which has about 22 and 7% higher heat exchange rate per unit land area than conventional single-layer arrangement, respectively. Furthermore, the thermal performance of the best arrangement for each type is evaluated for three different values of soil thermal conductivities.

Constructal Design of Circular Multilayer Microchannel Heat Sinks

Abstract Based on the constructal theory concepts, an investigation is carried out to optimize circular multilayer microchannels embedded inside a rectangular heat sink with different numbers of layers and flow configurations. The lower surface of the heat sink is uniformly heated, while both pressure drop and length of the microchannel are fixed. Also, the volume of the heat sink is kept fixed for all studied cases, while the effect of solid volume fraction is examined. All the dimensions of microchannel heat sinks are optimized in a way that the maximum temperature of the microchannel heat sink is minimized. The results emphasize that using triple-layer microchannel heat sink under optimal conditions reduces the maximum temperature about 10.3 °C compared to the single-layer arrangement. Further, employing counter flow configuration in double-layer microchannel improves its thermal performance, while this effect is less pronounced in the triple-layer architecture. In addition, it is revealed that the optimal design can be achieved when the upper channels of a multilayer microchannel heat sink have bigger diameters than the lower ones. Finally, it is observed while using two layers of microchannels is an effective means for cooling improvement, invoking more layers is far less effective and hence is not recommended.

Delocalization in Cr3+ luminescence of clinochlore: A pressure-induced transition from single-ion emission to pair emission

The luminescence spectra of Cr3+ in (Mg,Fe2+)5Al(Si3Al)O10(OH)8-clinochlore, a layered silicate compound, are reported to pressures of ∼25 GPa at 298 K: our results encompass emission from single-ions, paired neighbors and vibronic lines. A transition from sharp single Cr3+ ion (R-line) dominated emission to Cr-Cr pair (N-Line) dominated emission is observed under compression. Since Cr atoms are confined to a discrete layer within the structure, efficient Cr-Cr exchange only occurs within a single layer; the distance between the layers is too large for significant interlayer coupling to occur. This 2-dimensional, single-layer arrangement gives rise to three distinguishable Cr3+ nearest neighbor pairs. Neighbor lines are assigned based on ferromagnetic coupling of these three emitting pairs. We observe a decrease in the separation between the split components of the R-line under compression, confirming that the Cr sites become less distorted up to at least ∼11.0 GPa. An increase in overlap between eg orbitals of neighboring Cr-ions (corresponding to delocalization of the excited state) under compression also likely occurs. The R-to N-line transition is fully reversible and hysteresis is not observed, indicating that this transition is purely electronic in nature. The intensity transfer between the single-ion and paired-ion emission changes with a ∼1/4th power law as a function of the Cr-Cr separation.

Synthesis and spectral properties of preorganized BODIPYs in solutions and Langmuir-Schaefer films

Abstract In order to investigate the influence of molecular structure peculiarities of boron-dipyrrine dyes (BODIPYs) on their properties in solutions and supramolecular organization in Langmuir-Schaefer (LS) films, four new BODIPY dyes with various aliphatic, aromatic or mixed nature meso-subtituents were synthesized and investigated. Spectral characteristics (electronic absorption and fluorescence) of the synthesized compounds in organic solvents and LS-films were studied. Floating monolayers of the BODIPYs were formed from chloroform solutions placed onto water subphase in Langmuir-Blodgett through. Thin films were prepared using the Langmuir-Schaefer technique by the transfer of floating monolayers onto standard polished glass, ITO covered glass or pure silicon substrate. The variation of the dye structure we consider as a preorganization aiming to influence the structure of LS-films. The morphology and structure of the LS-films was examined by fluorescent microscopy, scanning electron microscopy, atomic force microscopy and small angle X-ray diffraction analysis. It was found that the introduced substituents have no substantial influence on the position of the absorption and fluorescence bands in dilute solutions. In contrast, the fluorescent characteristics of the LS-films significantly depend on the substituent nature. Therefore, this strategy could be used for the direct tuning of compounds fluorescent properties in LS-films. Concerning the LS-film surface characteristics it was proved that the films are homogeneous, without disruptions and only some widely-spaced microcrystals could be observed. With respect to the LS-film structure, the change of the substituents introduced to the BODIPY molecule did not influence the average given periodicity of layers (d = 0.3–0.4 nm). This value corresponds to a single-layer arrangement of BODIPY molecules located parallel to the substrate surface. Nevertheless, the diffraction peak intensities depended on the molecular structure of BODIPYs and therefore the structurization in thin films. Moreover, the combination of the rigid phenyl moiety with long alkyl chains in one compound completely suppresses the aggregation of molecules maintaining the intense fluorescence in thin films. On the basis of used range of experimental and calculation methods the intralayer and interlayer structures were proposed. Intermolecular hydrogen bond formation and π-π staking of the BODIPY cores were found to be the structure forming forces during the films manufacturing, resulting the differences in crystallinity of the materials. While the alkyl-substituents prevent the type of interactions and suppress the association of the dyes and formation of excimers. Compounds under investigation show a manifestation of the intense solvatochromic properties which allow their application as sensors, including naked eye sensorics for solution polarity. Besides, the obtained results broaden prospective of functional materials usage based on BODIPY thin films as components of optoelectronics.

Investigating Arrangement of Composite Drops in Two-Dimensional Microchannels Using Multiagent Simulations: A Design Perspective

Drops can self-organize in two-dimensional (2D) microchannels to form ordered arrangements. Design of microchannels that result in a particular pattern of drops for a specific purpose is difficult and nonintuitive due to the inherent complexity of the drop dynamics. We address the problem of understanding the arrangement of composite drops inside a microchannel. A multiagent modeling strategy that was recently proposed by us is employed to understand this complex design problem. We consider the design of a drop–drop contactor that results in an equal mix of A and B. We seek to find the inlet sequence of drops A and B that would result in the maximum contact between A and B in the ordered arrangement. We find that intuition-based results work well only for a single layer arrangement of drops. We attribute this anomalous behavior to the symmetry breaking instability of the drop patterns in these 2D microchannels. From the dynamic simulations, we understand why certain inlet sequences perform better than others. We then discuss the use of the simulation strategy in several possible design problems.

Double-layer orthogonal-offset photovoltaic platforms

Abstract Photovoltaic panels used for power generation are subject to significant wind loads of concern to mounting systems. A novel method of arranging photovoltaic surface in layers of non-overlapping panels is proposed for tracking systems to reduce wind load forces. The potential of this approach is assessed for double layer systems called DLOOP using Computational Fluid Dynamic turbulence modelling and wind tunnel tests. A consistent pattern of wind-force reduction is found as distance between double layers is increased up to and beyond the scale of the integrated panels’ side length. A 49 panel DLOOP arrangement when tested in high winds had the potential to carry 30% more panels than a single layer arrangement of side by side panels for equivalent wind loading.

The Characteristics of Oil Palm Shell Biochar and Activated Carbon Produced via Microwave Heating

Biochar was produced from oil palm shell via microwave-induced pyrolysis. The biochar was subsequently activated via microwave assisted CO2 activation. A simple single layer arrangement of the microwave absorber (coconut shell based activated carbon) and oil palm shell in the reactor was adopted during pyrolysis. In recent times, the treatment of oil palm biomass using microwave heating technology has been on the increase. Value added products such as bio-oil, gas, biochar and activated carbon are being produced while at the same time serving as waste management control. Biochar is seen as a promising climate mitigation tool. Activated carbons can be used as absorbent for the removal of pollutants from wastewaters, as air pollution control and as electrode for supercapacitor. This paper presents comparative study between the characteristics of oil palm shell biochar and oil palm shell activated carbon. BET surface area and Scanning Electron Microscopy (SEM) were analyzed to establish the characteristics of the biochar and activated carbon.

Hydrothermal Synthesis of Modified Hydrophobic Zn–Al-Layered Double Hydroxides Using Structure-Directing Agents and Their Enhanced Adsorption Capacity for p-Nitrophenol

Hollow microspheres of hierarchical ZnAl-layered double hydroxides (LDHs) were synthesized by a simple hydrothermal method using hexamethylenetetramine as precipitating agent, sodium dodecyl benzene sulphonate (SDBS) as surfactant and sodium tartrate, sodium citrate and sodium salicylate (SS) as structure-directing agents, respectively. Characterization results of the microspheres synthesized indicate that the modified ZnAl-LDHs formed a variety of morphologies, surface areas and pore volumes. The hierarchical porous ZnAl/SDBS-LDH prepared using SS possesses the highest surface area (128.9 m2/g) and the greatest pore volume (0.37 cm3/g). A possible formation mechanism of the special three-dimensional nanostructures from the primary LDH nanosheet building units is proposed on the basis of the interaction between SS molecules and LDH crystals. The size of the channel height is approximately equal to the diameter of the intercalated anion SDBS, indicating that SDBS is in a vertical single-layer arrangement. ...

Single layer linear array of microbeads for multiplexed analysis of DNA and proteins

In this study, a microfluidic platform was developed to generate single layer, linear array of microbeads for multiplexed high-throughput analysis of biomolecules. The microfluidic device is comprised of eight microbead-trapping units, where microbeads were immobilized in a linear array format by the exertion of a negative pressure in the control channel connected to each sieving microstructure. Multiplexed assays were achieved by using a mixture of different spectrally-encoded microbeads functionalized with specific probes, followed by on-chip reaction and detection. The microfluidic-based microbeads array platform was employed for multiplexed analysis of DNA and proteins, as demonstrated by the simultaneous discrimination of four HPV genotypes and the parallel detection of six different proteins. Compared with the off-chip protocols, the on-chip analysis exhibited better reaction efficiency, higher sensitivity and wider linear detection range. Visual inspection and identification of functionalized microbeads were facilitated by the single layer arrangement of microbeads so that accurate data acquisition can be performed during the detection process.

Conformation of Poly(Ethylene Oxide) Chains in Clay Galleries

The conformation and arrangement of poly(ethylene oxide) (PEO) chains in clay galleries is still controversial. In our work, various spectroscopic methods have been used to explore the conformation of PEO in clay galleries. The melt intercalation process is investigated using variable-temperature Raman spectroscopy. It is found that the sharp peak at 860 cm(-1) appears with an increase of the intercalation time, suggesting the formation of a crown-ether-like association between the cations and the PEO oxygen atoms. Two-dimensional infrared correlation analysis also suggests the presence of the crown-ether-like association between them. Therefore, a distorted helical conformation may be a more accurate way to describe the conformation of the PEO chains in the clay galleries, and a single-layer arrangement is suggested.

Single-Layered PDLC for Diffractive Optics

The electrically and spatially controllable coherent light diffraction by single-layered polymer-dispersed liquid crystal (PDLC) films is studied. Particularly, a wedge-formed thin film of E7/NOA65 microscale PDLC is examined. The PDLC single layer of thickness varying from a few micrometers to 25 μm contains liquid crystal (LC) droplets with double-truncated spherical shapes and a linear-gradient size distribution along the film length. The single-layer arrangement and compact packing of the micrometer-sized PDLC structure render the ellectrically-commanded coherent light diffraction controlled by LC/polymer interface.