Packing Of Layers Research Articles

Two highly-ordered global structures observed in packed beds of balls inside vibrated cylinder: Experiment and modelling of layers

During the vibration of plastic balls put into a cylinder three basic global orderings of the packed beds of balls were observed. Computed microtomography measurements enabled to determine coordinates of all balls. Internal layers and their structure in crystallized beds were studied and a model was developed to predict the radii of the layers. Structural analysis, based on the Coordination Polyhedron method, was used to identify all regular local structural units present in the bed: face-centred cubic (fcc), hexagonal close-packed (hcp), icosahedral (ico) and decahedral (dec). Two already-observed global structures, namely: random loose packing (RLP) and hexagonal layer (HL) with horizontal rows of balls, were investigated in detail. The third one, called columnar structure here, was found during the experiment and has the HL structure with vertical rows of balls. Its internal structure is highly ordered, composed of regularly-spaced columns of atoms with characteristic linear chains of non-crystalline dec units.

Gas–Water–Sand Inflow Patterns and Completion Optimization in Hydrate Wells with Different Sand Control Completions

Sand production poses a significant problem for marine natural gas hydrate efficient production. However, the bottom hole gas–water–sand inflow pattern remains unclear, hindering the design of standalone screen and gravel packing sand control completions. Therefore, gas–water–sand inflow patterns were studied in horizontal and vertical wells with the two completions. The experimental results showed that gas–water stratification occurred in horizontal and vertical standalone screen wells. The gas–water interface changed dynamically, leading to an uneven screen plugging, with severe plugging at the bottom and high permeability at the top. The high sand production rate and low well deviation angle exacerbated screen plugging, resulting in a faster rising rate of the gas–water interface. The screen plugging degree initially decreased and then increased as the gas–water ratio increased, resulting in the corresponding variation in the gas–water interface rising rate. Conversely, gas–water stratification did not occur in the gravel packing well because of the pore throat formed between the packing gravels. However, the impact of gas and water led to gravel rearrangement and the formation of erosion holes, causing sand control failure. A higher gas–water ratio and lower packing degree could result in more severe destabilization. Therefore, for the standalone screen completion, sand control accuracy should be designed at different levels according to the uneven plugging degree of the screen. For the gravel packing completion, increase the gravel density without destabilizing the hydrate reservoir, and use the coated gravel with a cementing effect to improve the gravel layer stability. In addition, the screen sand control accuracy inside the gravel packing layer should be designed according to the sand size to keep long-term stable hydrate production.

3D CFD-DEM modeling of sand production and reservoir compaction in gas hydrate-bearing sediments with gravel packing well completion

Sand production is one of the bottlenecks restricting the safe, efficient, and controllable production of hydrates. Enhancing the understanding of mesoscopic sand production responses is essential for sand production risk management. Yet, existing mesoscopic sand production models inadequately capture the effects of hydrate cementation, resulting in an incomplete assessment of the mechanical impacts of hydrates on sand production. Herein, we developed a new three-dimensional model for sand production in gas hydrate-bearing sediments (GHBSs) with gravel packing well completion, utilizing the coupled computational fluid dynamics and discrete element method (CFD-DEM). The model considers the coupled interactions of mechanical weakening and permeability variation in GHBSs caused by hydrate cementation reduction. Simulations are analyzed to clarify the responses of sand production and reservoir compaction under the coupled mechanical, hydraulic, and sand control completion in GHBSs during depressurization. The high fluid flow rate induced by a high production pressure differential can promote sand production and reservoir compaction. Additionally, the high effective stress and high hydrate dissociation rate induced by a high production pressure differential are beneficial for initial sand production, but they can also prematurely lead to gravel packing layer obstruction, inhibiting the final sand production. This also results in a dual impact on compaction deformation, enhancing it through compaction while decelerating it by inhibiting sand production. This work provides a viable simulation idea and preliminary insights into the mechanism of sand production from GHBSs.

Accelerating Laser Powder Bed Fusion: The Influence of Roller-Spreading Speed on Powder Spreading Performance

The powder spreading process is a fundamental element within the laser powder bed fusion (PBF-LP) framework given its pivotal role in configuring the powder bed. This configuration significantly influences subsequent processing steps and ultimately determines the quality of the final manufactured part. This research paper presents a comprehensive analysis of the impacts of varying spreading speeds, which are enabled by different roller configurations, on powder distribution in PBF-LP. By utilizing extensive Discrete Element Method (DEM) modelling, we systematically examine how spreading speed affects vital parameters within the spreading process, including packing density, mass fraction, and actual layer thickness. Our exploration of various roller configurations has revealed that increasing spreading speed generally decreases packing density and layer thickness for non-rotating, counter-rotating, and forward-rotating rollers with low clockwise rotational speeds (sub-rolling) due to powder dragging. However, a forward-rotating roller with a high clockwise rotational speed (super-rolling) balances momentum transfer, enhancing packing density and layer thickness while increasing surface roughness. This configuration significantly improves the uniformity and density of the powder bed, providing a technique to accelerate the spreading process while maintaining and not reducing packing density. Furthermore, this configuration offers crucial insights into optimizing additive manufacturing processes by considering the complex relationships between spreading speed, roller configuration, and powder spreading quality.

Study Finds Compact Carbon-Capture Modules Feasible on Offshore Production Facilities

_ This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper OTC 34825, “Implementation of Compact Carbon-Capture Modules on Offshore Hydrocarbon Production Facilities,” by Jaime H. Tan and Rizal A. Hassan, Technip Energies, and Umberto Cornelis, KANFA, et al. The paper has not been peer reviewed. Copyright 2024 Offshore Technology Conference. _ Carbon capture and storage has been implemented onshore successfully by different industries, including utilities and waste treatment, to capture CO2 from flue gases after the combustion of fossil fuels. Duplicating this success for offshore hydrocarbon processing facilities can be challenging because of deck-space constraints and marine environmental conditions. The complete paper describes the development of a compact carbon-capture module design for post-combustion carbon capture and its potential implementation on typical offshore hydrocarbon production facilities. Solvent Absorption Technology for Post-Combustion Carbon Capture The process technology at the core of the compact carbon-capture module is based on a solvent-absorption technique and a proprietary amine-based solvent. First, feed gas is quenched and saturated in a circulated water prescrubber. The gas contacts the lean amine solution in a countercurrent mass-transfer packed absorption column, and CO2 is absorbed while the treated gas exits to the atmosphere. Midway through the column, partially loaded amine is removed from the tower, cooled, and reintroduced over a layer of mass-transfer packing. CO2-rich amine from the absorption column is pumped through a lean-rich amine heat exchanger and then to the regeneration column. The rising, low-pressure saturated steam in the column regenerates the lean amine solution. CO2 is recovered as a pure, water-saturated product. Lean amine is pumped from the stripper reboiler to the absorption column for reuse in capturing CO2. Finally, the CO2 is directed to byproduct-management systems. The pure CO2 streams produced from the system may be sequestrated or used for applications such as enhanced oil recovery. Design of Offshore Carbon-Capture Modules For offshore applications, the carbon-capture modules must be more compact and lighter compared with carbon-capture systems developed for onshore applications. The absorber column is the critical component of the carbon-capture module because of its weight, footprint, and height. To reduce the overall height of the absorber for offshore application, an innovative configuration has been adopted: The bottom section of the absorber is placed on top of the prescrubber/direct contact cooler (DCC), and the top section of the absorber and the wash-water section comprise the second column. With this arrangement, the maximum height of the columns is limited to approximately 25 m. Because the lower absorber section is placed on top of the prescrubber/DCC, the in-between chimney tray is designed to be totally leakage-free to avoid losses of amines into the DCC water loop. A patent-pending compact absorber column design has been developed. The column wall construction will be a part of the overall module support structure, with cantilevered platforms for supporting carbon-capture equipment. The equipment for compression, injection, and treatment of CO2 is placed on a separate submodule. This module design benefits from footprint and weight savings of potentially more than 20% compared with typical cylindrical absorber column designs.

Adsorptive removal of a nitrate ion from the aqueous solution of sodium nitrate by application of double fixed-bed column

This study focuses on the removal of nitrate ions from aqueous solutions using rice husk activated carbon (RHAC). The RHAC was subjected to characterization via Fourier transform infrared (FTIR), scanning electron microscopy coupled with energy dispersive spectroscopy (SEM-EDS), and X-ray florescence (XRF) to ascertain its functional groups, surface morphology, and oxide/elemental composition, respectively. Batch experiments were conducted to assess the impact of nitrate concentration, bed height, and number of packing layers on removal efficiency. FTIR spectra revealed favorable sorption-related functional groups within RHAC, while SEM analysis indicated the presence of effective sorption sites on its surface. EDS analysis of the rice husk adsorbent before adsorption (RHBS) demonstrated a significant composition of Si (42.20%), O (35.30%), and Ca (12.33%). The batch study unveiled a concentration-dependent decrease in nitrate removal efficiency, alongside the enhanced performance with increased bed height and number of packing layers. Kinetic data fitting favored the Yoon–Nelson and Adams–Bohart models. Overall, RHAC exhibited efficient nitrate ion removal, with column performance notably improved by utilizing multiple packing layers. These results will enhance our understanding of the mechanisms involved in removing nitrate ions and highlight the potential effectiveness of RHAC, especially when utilized with multiple packing arrangements in column setups.

Unraveling the relationship between microstructure of CMS membrane and gas transport property using molecular simulation

AbstractCarbon molecular sieve (CMS) membranes are attractive for energy‐efficient gas separations. A challenge with the fabrication of a high‐performance CMS membrane is fine‐tuning its microstructure for precise and efficient separation. This necessitates a molecular‐scale analysis to understand its microstructure–performance relationship. Herein, molecular simulations were performed to unravel the relationships between four similar‐sized CMS matrices with different microstructural characteristics (e.g., chemical composition and micromorphology) and their gas transport properties. Results show that the disordered packing of carbon layers, leading to the formation of ultramicropore (2–7 Å), originates from stereoscopic sp3 hybridized carbon atoms rather than non‐carbon (oxygen) atoms. The size‐sieving ability of CMS depends positively on ultramicroporosity; the adsorption capacity is strengthened and then weakened with the increase of ultramicroporosity. Competitive effects are observed in binary‐mixture transport, and it is expected that the separation performance can be optimized by a reasonable distribution of ultramicropores combined with the affinity of oxygen‐containing species.

Triflic acid-promoted Friedel–Crafts-type carbocyclization of alkenylated biphenyl derivatives: Synthesis and photophysical studies of novel 9,10-dihydrophenanthrenes

An efficient metal-free, triflic acid-promoted intramolecular Friedel–Crafts-type carbocyclization of alkenylated biphenyl derivatives is discussed. This method provides an elegant route for the construction of 9,10-dihydrophenanthrenes of biological significance in good to excellent yields. The carbocyclization reaction is likely to proceeds via activation of terminal CC bond of alkenylated biphenyl derivatives followed by subsequent aromatic electrophilic substitution to give desired carbocyclic products. Single crystal X-ray diffraction analysis of compound 10d revealed that the crystals are packed in AB-AB layer packing, where the molecules are aligned in anti-parallel fashion. Notably, all of the synthesized 9,10-dihydrophenanthrenes exhibited blue to greenish yellow fluorescence with λmax = 418–481 nm range. The stokes shift, quantum yield and optical band gap of tricyclic products were computed using their absorption and emission spectra. A significant positive solvatochromic effect was observed for 9,10-dihydrophenanthrene derivative 10l, which is a characteristic of ICT interactions.

Crystal structures of four thio-glycosides involving carbamimido-thio-ate groups.

The compounds 2',3',4',6'-tetra-O-acetyl-β-d-gluco-pyranosyl N'-cyano-N-phenyl-carbamimido-thio-ate (C22H25N3O9S, 5a), 2',3',4',6'-tetra-O-acetyl-β-d-galacto-pyranosyl N'-cyano-N-phenyl-carbamimido-thio-ate, (C22H25N3O9S, 5b), 2',3',4',6'-tetra-O-acetyl-β-d-galacto-pyranosyl N'-cyano-N-methyl-carbamimido-thio-ate (C17H23N3O9S, 5c), and 2',3',4',6'-tetra-O-acetyl-β-d-galacto-pyranosyl N'-cyano-N-p-tolyl-carbamimido-thio-ate (C23H27N3O9S, 5d) all crystallize in P212121 with Z = 4. For all four structures, the configuration across the central (formal) C=N(CN) double bond of the carbamimido-thio-ate group is Z. The torsion angles C5-O1-C1-S (standard sugar numbering) are all close to 180°, confirming the β position of the substituent. Compound 5b involves an intra-molecular hydrogen bond N-H⋯O1; in 5c this contact is the weaker branch of a three-centre inter-action, whereas in 5a and 5d the H⋯O distances are much longer and do not represent significant inter-actions. The C-N bond lengths at the central carbon atom of the carbamimido-thio-ate group are almost equal. All C-O-C=O torsion angles of the acetyl groups correspond to a synperiplanar geometry, but otherwise all four mol-ecules display a high degree of conformational flexibility, with many widely differing torsion angles for equivalent groups. In the crystal packing, 5a, 5c and 5d form layer structures involving the classical hydrogen bond N-H⋯Ncyano and a variety of 'weak' hydrogen bonds C-H⋯O or C-H⋯S. The packing of 5b is almost featureless and involves a large number of borderline 'weak' hydrogen bonds. In an appendix, a potted history of wavelength preferences for structure determination is presented and it is recommended that, even for small organic crystals in non-centrosymmetric space groups, the use of Mo radiation should be considered.

SURFACE PROPERTIES AND MICELLIZATION OF SODIUM ALKYLSULPHATES IN THE PRESENCE OF LOW-MOLECULAR ALCOHOLS

The process of micellization of sodium alkyl sulfates (SAS : sodium decyl- (SDS) and dodecylsulfate (SDDS)) of formation in aqueous solution without or with alcohols including propanol-1, propanol-2 and butanol-1 and their adsorption behavior at air-liquid interface were investigated with both the tensiometry and the conductometry at 298 K. The effect of chain length of alcohol on micellar and interfacial properties were discussed. Some parameters including surface excess concentration (Γmax), minimum area per surfactant molecule (Smin) at air-liquid interface, degree of ionization of micelle, and standard free energy of adsorption and micellization, etc. are estimated. It was experimentally established that the introduction of 0.5-1.0 mol/dm3 of alcohols into surfactant solutions contributes to the process of micellar formation of SAS and increases the stability of the micellar phase, as evidenced by the observed synergistic effect on the critical micelle concentration (CMC). The addition of different alcohols changes the values of Γmax, Smin, CMC of SDS and SDDS and induces an increase in degree of ionization (β) of micelle relative to that in pure water. When alcohols are introduced into SDS and SDDS solutions, the degree of ionization of micelles at a constant length of the alkyl radical of surfactant moderately increases with increasing alcohol content in the solution and ranges from 0.50-0.73 and 0.38-0.75, respectively. Also, the effect of alcohol was discussed. The obtained thermodynamic parameters were used to confirm these behaviors of interfacial adsorption or micellization. An increase in chain length of alcohol promotes the micellization process. The CMC values decrease with increasing length of the alkyl radical of alcohols. Propanol-1, compared to propanol-2, somewhat reduces the value of SDS and SDDS CMC to a greater extent. Standard free energy of micellization ∆G0mic, also confirms the micellization behavior. Standard free energy of adsorption (∆G0адс) indicates that an increase in the chain length of alcohol in aqueous solution is favorable to the adsorption of SDS and SDDS at air-liquid interface. A comparison of the values of the standard free energy of adsorption and micelle formation in sodium alkyl sulfates – alcohols – water systems showed that adsorption is the most thermodynamically advantageous process in the studies systems, and the packing of surfactant “molecules” in micelles is less dense, compared to packing in a mixed adsorption layer.

3D hierarchical graphene-based composite for ultra-high heat-conducting film

In order to pursue lightness and portability, modern electronic devices usually use a compact layout to place various components, but this highly integrated design increases the heat density of the device and causes heat accumulation. Excessive heat accumulation will reduce the reliability of the device and even cause thermal failure. The advantages of light weight, easy processing and low cost of polymer-based thermally conductive composites have become main concerns of modern thermal management materials, but the low thermal conductivity (TC) has seriously limited their application. Here, 3D hierarchical anisotropic oriented graphene-based composites with high TC are fabricated by layer-by-layer self-assembling of one-dimensional carboxylated cellulose nanofibers (CNF–C) and poly dopamine modified nickel particle-coated two-dimensional graphene nanosheets (PDA-Ni@GNS). Owing to the well-defined flaky packing layers and the hydrogen bonding, the composite exhibits not only sufficiently high in-plane TC of 28.8 W m−1 K−1 and tensile strength of 124 MPa, but also exhibits hydrophobic property. A generalized four-parameter model (FPM) is found to reasonably predict the entire CPU temperature evolution versus time. This work presents a facile strategy for constructing 3D hierarchical interfacial structure to obtain excellent versatility of anisotropic thermal management composites.

The Peculiar H-Bonding Network of 4-Methylcatechol: A Coupled Diffraction and In Silico Study.

The crystal structure of 4-methylcatechol (4MEC) has, to date, never been solved, despite its very simple chemical formula C7O2H8 and the many possible applications envisaged for this molecule. In this work, this gap is filled and the structure of 4MEC is obtained by combining X-ray powder diffraction and first principle calculations to carefully locate hydrogen atoms. Two molecules are present in the asymmetric unit. Hirshfeld analysis confirmed the reliability of the solved structure, since the two molecules show rather different environments and H-bond interactions of different directionality and strength. The packing is characterised by a peculiar hydrogen bond network with hydroxyl nests formed by two adjacent octagonal frameworks. It is noteworthy that the observed short contacts suggest strong inter-molecular interactions, further confirmed by strong inter-crystalline aggregation observed by microscopic images, indicating the growth, in many crystallization attempts, of single aggregates taller than half a centimetre and, often, with spherical shapes. These peculiarities are induced by the presence of methyl group in 4MEC, since the parent compound catechol, despite its chemical similarity, shows a standard layered packing alternating hydrophobic and polar layers. Finally, the complexity and peculiarity of the packing and crystal growth features explain why a single crystal could not be obtained for a standard structural analysis.

Revealing packing structure in benzimidazole-containing polyimides: Anti-parallel offset π-π stacking

Aromatic polyimides (PIs) exhibit excellent mechanical and thermal properties due to the charge transfer (CT) interactions. The introduction of benzimidazole with hydrogen interactions is a notably effective strategy for yielding exceptional superheat resistance and high thermal dimensional stability of PIs. Decoupling the stacking behavior under CT interactions and hydrogen interactions is crucial for elucidating the behavior of PIs macromolecules. Herein, the packing structure of PIs guided by hydrogen interactions was visualized using three plausible model compounds and theoretical simulations. The phthalimide fragment exhibited a preference for anti-parallel offset stack π-π stacking, while the phenylbenzimidazole fragment formed a shoulder-to-shoulder arrangement, resulting in the adoption of a Mixed Layer Packing (MPL) conformation, which is not the common Preferred Layer Packing (PLP) conformation. The CT interactions of phthalimide served as the primary stacking driving force, rather than the hydrogen interaction of benzimidazole. The intrinsic nature of packing behavior was that the minima and maxima parts of the electron density deviated from the midperpendicular of benzene and succinimide, where the LOL-π map, ESP map and SAPT calculations provided insights into the microscopic electronic structure. Finally, experimental PI fibers was prepared and their XRD pattern further confirmed the presence of an anti-parallel offset π-π stack conformation.

Imaging the Iodine Sorption-Induced Synchronous Skeleton-Pore Interactions of Single Covalent Organic Framework Particles.

Covalent organic frameworks (COFs) are promising iodine adsorbents. For improved performances, it is critical and essential to fundamentally understand the underlying mechanism. Here, using the operando dark-field optical microscopy (DFM) imaging technique, the observation of an extraordinary structure shrinkage of 2D triphenylbenzene (TPB)-dimethoxyterephthaldehyde (DMTP)-COF upon the adsorption of I2 vapor at the single-particle resolution is reported. Combining single-particle DFM imaging with other experimental and theoretical methods, it is revealed that the shrinkage mechanism of the TPB-DMTP-COF is attributed to the I2 sorption-induced synchronous skeleton-pore interactions. The redox reaction of I2 and TPB-DMTP-COF yields some cationic skeletons and I3 - species, which triggers the multi-directional halogen-bonding interactions of I2 and I3 - as well as strong cation-π interactions between neutral and cationic skeletons, accompanying the synchronous in-plane skeleton shrinking in the xy plane and compact out-of-plane layer packing in the z-direction. This understanding of the synchronous action between the skeleton and pore breaks the perspective on the structure robustness of 2D COFs with excellent stability during the I2 uptake, which offers pivotal guidance for the rational design and creation of advanced microporous adsorbents.

Carboxylated cellulose composite film fabricated via layer‐by‐layer self‐sssembly for thermal management material with ultra‐high thermal conductivity

AbstractWith the development of 5G equipment, aerospace, sensors, thermal management devices and other fields in the direction of high power, high performance and miniaturization, the heat released during usage increases significantly, leaving great application prospects for heat dissipation materials. In spite of great attention paid to film materials due to their light weight and flexibility, they have the obvious disadvantage of poor thermal conductivity. In this work, carboxylated cellulose (CNF‐C)/dopamine‐coated nickel‐coated graphene (PDA‐Ni@GNS) composite films with high in‐plane thermal conductivity (in‐plane TC) have been fabricated by a simple vacuum‐assisted filtration method. In the prepared composite films, the flaky packing layers were found to be stacked orderly and form an excellent thermally conductive network, resulting in an increase in in‐plane TC by 322.1% (sample W4) as compared with that of neat films. By comparing the in‐plane TCs of the composite films with that of a commercial gasket, it was readily seen that the present composite films had fairly excellent heat dissipation properties. The composite exhibits not only sufficiently high in‐plane TC and tensile strength of 149.02 MPa but also exhibits hydrophobic property, imparting the composite films good working stability under extreme conditions, which ensured of their potential applications in thermal management materials.Highlights The introduction of Ni promotes the construction of heat conduction path. High in‐plane TC is obtained through layer‐by‐layer self‐assembly. The modification of filler enhanced the mechanical properties of the films. The modification of fillers led to the hydrophobicity of the film. The introduction of PDA made the films have insulating properties.

Novel cobalt-incorporated two dimensional covalent organic frameworks for supercapacitor applications

Covalent-organic frameworks (COFs), are a promising new class of crystalline porous organic materials with confined structures either in 2D or 3D domains. The current study focuses on using a solvothermal approach consisting of sealed pyrex tubes to synthesize two-dimensional TBP-COF and TBP-COF that have been doped with cobalt (Co) (TBP-Co@COF). The results of the experimentally acquired X-ray diffraction study were compared with those from simulations, and it was discovered that both are in good agreement. A thorough theoretical analysis of the layer packing in AA stacking (P1) and AB stacking (P1) modes using the Materials Studio revealed that AA stacking is more stable than the AB stacking (P1) structure. The formation of imine linkage and incorporation of Co into the COF are indicated by the result of XPS. Unaggregated dispersion of Co particles can be seen on the square and rectangular sheets of TBP-COF in TEM and SEM images. Both materials are fabricated as electrode materials and evaluated for their supercapacitor applications. The TBP-Co@COF shows an enhanced specific capacitance (CSp) of 975F/g compared to the TBP-COF (827F/g) at 2 mV/s scan rate. TBP-Co@COF exhibit an energy density (ED) of 69 Wh/kg even at a high power density (PD) of 75000 W/kg and also retains 79 % of its initial capacitance up to 2000 cycles. TBP-COF and TBP-Co@COF were fabricated for an asymmetric supercapacitor device (ASD) and found to exhibit a CSp of 191F/g at a scan rate of 2 mV/s.

Numerical study on heat and mass transfer performance of a natural draft wet cooling tower based on baffle optimization

In the natural draft wet cooling towers (NDWCTs), the resistance of the packing layer to air and the effect of the circular design of its cross-section, the air reaches the tower center area to overcome the maximum resistance. The air velocity in the center of the tower is low and the heat transfer is poor. To improve the performance of the cooling tower, the optimized design of the cooling tower distribution pipe surface with baffles is firstly investigated. Then, the three-dimensional numerical model of NDWCTs is developed and validated with power plant data. Finally, the effect of plates on cooling tower performance is analyzed through the influence of baffles on the cooling tower air field and combined with the circulating water temperature drop, evaporation, and ventilation. Results show that the air field uniformity inside the cooling tower is effectively improved by adding baffles. The cooling efficiency of the circulating water inside the cooling tower is improved. The air velocity in the packing zone is significantly increased by adding the a1a2 type baffle and the air temperature and circulating water in the central area of the tower decreases significantly and the a1a2 baffles performed best in terms of circulating water temperature drop in the packing zone and were able to significantly improve the cooling effect. The cooling tower with pro-wall baffles can cool the circulating water better than the conventional cooling tower. This study provides ideas for subsequent structural and energy efficiency studies.

DUST COLLECTION EFFICIENCY UNDER IN-PHASE TURBULENCE CONDITIONS IN THE PRESENCE OF PHASE TRANSITIONS

The article presents the results of a study of the dust collection efficiency in a regular packing layer of a rotoclone-type hybrid apparatus on the particle inertia index in the presence of phase transition processes. The effect of phase transitions on the efficiency of gas purification processes under inphase turbulence conditions is considered. Based on the conditions of stability of the in-phase vortex formation regime of the gas phase in a regular packing layer, the dominant influence of turbulent diffusion mechanisms on the intensity of phase transition processes and, as a consequence, on the dust collection efficiency has been established. In this case, the predominant influence is in the area of highly dispersed and finely dispersed dust fractions. The results of the experimental studying the patterns of dust collection efficiency depending on the particle inertia index in the presence of phase transition processes are presented. The studies were carried out for three phase transition modes: condensation of vaporsfrom a vapour-gas mixture, evaporation of a spraying liquid as well as a neutral mode. Using A.N. Kolmogorov’s hypothesis,the basic equations and results of calculating the numerical values of local characteristics of a turbulent gas flow in a regular packing layer are presented under the assumption of isotropic turbulence realized in a layer of a regular packing, whose local characteristics do not depend on coordinates and direction.

Characterization of construction and physical properties of composite oleogel based on single low molecular weight wax and polymer ethyl cellulose

The combination of oleogels has recently begun to receive scientific attention because a single oleogels may not adequately compensate for the multiple roles of solid fat in complex food systems. In this study, corn oleogels were prepared from candelilla wax (CLW), beeswax (BW), carnauba wax (CW), and ethyl cellulose (EC) with different mass ratios, and their physicochemical properties were characterized in terms of heat, rheology and microstructure. The strength of oleogel was CLEOs > BEOs > CWEOs. With the increase of the amount of wax in the oleogelators, the color L* value, the ability to bind oil, the melting temperature, the hardness and the viscosity and strength of the oleogels were increased. Microscopic analysis showed that the gel network was formed based on the crystallization and self-organization of gel molecules, and the two oleogelators showed independent crystallization behavior in the oleogel. Furthermore, the FTIR spectra showed that noncovalent bonds of van der Waals forces played a dominant role in the composite oleogel network formed through physical entanglement as compared to hydrogen bonds. XRD results showed higher lateral packing of molecular layers in oleogels prepared from combined EC and wax compared to oleogels prepared from a single oleogelator. This study provides a reference for the development of a new composite oleogel system.

Enhancement of intermolecular aggregation on solvent-influenced strong hydrogen-bonded single crystal.

The intermolecular aggregation between the solvent and organic molecules is covered in the current article. 4,4'-(Buta-1,3-diyne-1,4-diyl)dibenzoic acid (DADBA) was used as an organic molecule and dimethyl sulfoxide (DMSO) as a solvent to create the target compound DADBA-DMSO. The material's hydrogen bonding and intermolecular aggregation were determined by appropriate characterization methods, including single-crystal X-ray diffraction (XRD), Fourier-transform infrared (FTIR), photoluminescence (PL), and cyclic voltammetry (CV) analysis. Each hydrogen of the carboxylic group is coordinated by oxygen from the DMSO molecule in the stiff planar layer packing that makes up the DADBA-DMSO crystal structure.