Absorption Unit Research Articles

Derivation and Experimental Validation of Multi-Parameter Performance Optimization of Magnetic Adhesion Unit of Wall-Climbing Robot

Wall-climbing robots have broad application potential in industrial equipment inspection, chemical storage tank maintenance, and high-altitude operations. However, their practical implementation is challenged by the robots’ adhesion requirements in complex wall environments. This study uses a systematic methodology integrating computational simulation and experimental validation to design and optimize a magnetic adsorption system for wall-climbing robots. Firstly, an adjustable suspended magnetic adhesion unit is designed to achieve intelligent control of a wall-climbing robot’s adhesion force on a wall surface. The Maxwell software (AnsysEM21.1) is used to simulate and analyze the critical parameters of the magnetic adsorption unit, including the thickness of the magnet and yoke, as well as the distance and angle between the magnet and the wall surface. Then, a magnetic wheel is designed for the wall-climbing robot based on the optimization of the structure and parameters of the magnetic adhesion unit. The absorption and demagnetization of the magnetic wheels are achieved by rotating the magnetic absorption unit. Subsequently, the simulation results are verified on the experimental platform, and adhesion performance tests are conducted on both standard flat surfaces and inclined walls. The results show that the optimized single magnetic adhesion unit gives the wall-climbing robot an adhesion force of 2767 N under normal working conditions, with a simulation experiment error margin as low as 8.3%. These results both provide theoretical guidance and highlight practical methodologies for developing high-performance magnetic adsorption systems in complex operational environments.

TEMPO-Oxidized Spruce Galactoglucomannan-Biopolymer with Enhanced Antioxidant Activity and Selective Heavy-Metal Sorption.

This study examines galactoglucomannan, a well-studied biopolymer isolated from Siberian spruce (Picea obovata Ledeb). Due to its structure, abundant with hydroxyl groups, galactoglucomannan's properties, such as heavy-metal ion affinity, are considered to be mediocre. Nevertheless, there are various ways to enhance its functionality via oxidative TEMPO/NaBr/NaOCl processing. This work is concerned with the determination of the oxidation effect on the structure and performance properties, such as thermal decomposition behavior, antioxidant activity, and selective heavy-metal sorption. In the results, TEMPO-oxidized galactoglucomannan yields vary in the range of 78.3 ± 6.4 wt.%. The carboxylate group in the oxidized derivative represents up to 0.084 g/1 g of the sample. According to antioxidant activity tests, the oxidized galactoglucomannan exceeds the initial sample in terms of hydroxyl radical scavenging ability. The spectral characteristics of the initial and oxidized galactoglucomannan samples reveal the differences in absorption units (1725, 1610, and 1371 cm-1). The preservation of the polymeric structure was confirmed by the gel permeation chromatography analysis results. The heavy-metal ion capacity of galactoglucomannan is higher for the oxidized derivative, which demonstrated Cd2+, Fe2+, Cu2+, and Pb2+ adsorption values of 166.8 mg/g, 142.8 mg/g, 150.0 mg/g, and 199.2 mg/g, accordingly. The obtained result of the competitive heavy-metal ion adsorption of oxidized galactoglucomannan also exceeds its initial form, as characterized by its summary 143.1 mg/g capacity.

Gas Endeavour: An Innovative Equipment for Estimating Methane Kinetics During In Vitro Rumen Fermentation.

The growing need to reduce methane emissions from ruminants while enhancing feed utilization has driven the development of innovative in vitro measurement techniques. This review examines the Gas Endeavour (GES), an automated volumetric apparatus that quantifies both total gas and methane production in real time during rumen fermentation. Utilizing the principles of liquid displacement and buoyancy, the GES integrates a thermostatically controlled water bath, specialized gas flow cells, and an alkaline CO2 absorption unit to deliver precise kinetic data on fermentation. Compared to conventional methods-which often rely on manual measurements and post-incubation gas chromatography-the GES provides continuous monitoring and immediate data acquisition, reducing labour and potential errors. This review discusses the system's design, operational challenges such as controlling headspace pressure and ensuring consistent inoculum preparation, and its applications in both animal nutrition and biomethane potential assessments. The findings suggest that, with further standardization and protocol refinement, the GES could significantly advance research aimed at optimizing feed digestibility and mitigating methane emissions in ruminant production systems.

Thermal Desorption and Extraction Coupled With Gas Chromatography and Mass Spectrometry for the Quantification of Polystyrene Nanoplastic in Pak Choi.

It has been demonstrated that microplastics and nanoplastics (MNPs) can be found in soil and that MNPs can be taken up by plants. In order to conduct a risk assessment for human consumption, it is necessary to have an estimate of the mass concentration of plastics in crops. A new thermal extraction and desorption coupled with gas chromatography and mass spectrometry (TED-GC/MS) method has been developed for the analysis of polystyrene (PS) in pak choi. In this study, a thermogravimetric analyser (TGA) equipped with a thermal absorption unit (TAU), was coupled with a GC system equipped with a thermal desorption unit (TDU2), a (5%-phenyl)-methylpolysiloxane GC column and a GC/MSD single quadrupole mass spectrometer. The systems were connected via an MultiPurposeSampler (MPS). Samples were pyrolyzed in the TGA; the pyrolysis products were trapped on a PDMS polymer bar, desorbed in the TDU, separated and analysed on the GC/MS system. The purpose of this study was to investigate the qualitative and quantitative detection of PS MNPs in pak choi. The determined limit of detection (LOD) was 0.09 μg, and the limit of quantification (LOQ) was 0.28 μg PS absolute. Plants treated with 100 nm of particles 19.0 ± 6.7 μg/g DM PS and in the plants treated with 500 nm of particles 64.1 ± 8.6 μg/g DM PS have been found. This study was the first to use a TED-GC/MS method for the detection of PS nanoplastics of different sizes in pak choi and thus provides an important basis for the determination and risk assessment of PS in vegetables.

The Impact of Melatonin on the Biochemical Indicators of Tomato Plant Seedlings that are Growing Under Salt Stress Conditions in Vitro

Abstract The Plant Tissue Culture Laboratory under the Department of Horticulture and Landscape Engineering at Al-Qasim Green University’s College of Agriculture performed this study from 2023 to 2024. Two molecules of melatonin were used in the experiment, with concentrations of 0.2, 0.4, and 0.2 mg/L, and 50, 100, and 50 mmol/L of sodium chloride. The goal was to find out how melatonin affected biochemical markers of the Mahavis cultivar tomato plant when it was stressed by salt. According to the results, the sodium chloride intervention therapy (100 mmol/L + 0 melatonin) worked better to raise proline levels, peroxidase enzyme activity, and catalase enzyme activity in the shoots. These values were 40.700 absorption units per minute, 11.99 absorption units per minute, and 0.590 mg/g dry weight, respectively. These values exceeded the comparative concentration, which demonstrated the lowest rate of absorption. recorded the lowest rate. The treatment (0 sodium chloride + 0.4 mg/L melatonin) considerably affected the nitrogen and protein percentages in the seedlings, resulting in values of 1.484% and 9.280%, respectively.

Elucidating the corrosion of carbon steel in hybrid monoethanolamine solutions containing methanol or n-methyl-2-pyrrolidone

Corrosion has been a persistent issue in carbon dioxide (CO2) absorption unit that needs to be resolved in order to prolong the life span of the absorber unit. In this regard, understanding the corrosion behaviour, particularly in hybrid monoethanolamine (MEA) solutions, is crucial. This study aims to give detail information on the role of different process parameters, encompassing types of amine solution, temperature, and CO2 loading on the corrosion behaviour of carbon steel in system containing hybrid solution of monoethanolamine (MEA) and methanol (MeOH) or N-methyl-2-pyrrolidone (NMP). Here, the corrosion extent of the carbon steel was evaluated using gravimetric experiments. The results indicated that the corrosion rate of carbon steels, when submerged in various amine solutions, increased with higher solution temperatures and the presence of CO2. In line with the Raman spectroscopy results and the surface morphology analysis, results also showed that the carbon steel coupons immersed in MEA+MeOH had the lowest corrosion rate.

A novel approach and exergy analysis for a concentrated photovoltaic system for thermoelectric absorption cooling

Abstract A unique and distinctive absorption-thermoelectric cooling system powered by a photovoltaic–thermal unit is presented in this work with a thorough exergy analysis. The photovoltaic module supplied electricity to the thermoelectric cooler, while heat energy fueled the absorption unit. The solar module’s efficient cooling enhances electrical output while diminishing the quality of thermal energy. Consequently, the thermoelectric cooler exhibits superior cooling performance compared to the absorption cooler. The primary objectives of the study are the coefficient of performance, exergy efficiency, and cooling capacity of the photovoltaic–thermal absorption system. A mathematical representation of the suggested system is shown. The model is assessed at a local solar irradiance of 1000 W/m² and various operational temperatures. The system coefficient of performance climbed from 0.67 to 0.73, while the exergy efficiency declined from 0.34 to 0.17 as the photovoltaic–thermal temperature rose from 60°C to 120°C, achieving a peak cooling capacity of 6 kW.

Reaction mechanisms of Sn-based polarity-change copolymer resists with different counter anions, designed for extreme ultraviolet lithography

Abstract The development of high-resolution resists with a highly absorptive element for extreme ultraviolet (EUV) photons has attracted much attention for next-generation lithographic applications. In this study, the radiation-induced reactions of polarity-change copolymer resists comprising tetraphenyltin (an EUV absorption unit) and phenyl dibenzothiophenium salts (polarity-change units) are investigated via electron-pulse radiolysis, electron-beam (EB) radiolysis, γ radiolysis, time-of-flight secondary-ion mass spectrometry (TOF-SIMS), quartz crystal microbalance (QCM) method, and contact angle measurement. Their lithographic performances are preliminary evaluated using a 125 keV EB writer. Trifluoromethanesulfonate, benzene sulfonate, and salicylate are used as counter anions for phenyl dibenzothiophenium cations. The effects of the counter anions on the radiation-induced reactions and yields of the main radiolytic products are small, whereas the resolution and sensitivity improve significantly with the increase in the pK a (or dipole moment) of corresponding acids for counter anions owing to the suppression of transient swelling layer formed during the development.

A perfect ultra-wideband solar absorber with a multilayer stacked structure of Ti-SiO2-GaAs: structure and outstanding characteristics.

In this paper, we introduce an entirely new solar absorber design-a multi-layer periodic stacked structure. Through coupling effects, this design has perfect ultra-wideband absorption characteristics. The absorber structure is composed of four absorption units with varying cycle lengths, which are cyclically stacked on the surface of the refractory metal Cr. Each cycle encompasses three-layer nanosheets of Ti-SiO2-GaAs. We verify through finite difference time domain method (FDTD) simulations that the absorber achieves an absorption efficiency of 97.8% within the wavelength range of 280 nm to 3000 nm, with an average efficiency of 96.6% under the AM1.5 standard solar spectrum. The absorber can achieve such a remarkable absorption effect because of surface plasmon resonance (SPR) and Fabry-Pérot resonance effects. At 1500 K, this structure exhibits a thermal radiation efficiency of up to 97.83%. Furthermore, the design is not affected by polarization and it is less affected by the incident angle of the light source. These absorption spectra remain consistent regardless of whether it is in the TE or TM mode. Even when the angle of incidence is increased to 60 degrees, the absorption efficiency remains high. Its unique structure and excellent performance characteristics provide higher solar energy efficiency. These outstanding features enable solar absorbers to have broad application potential in improving solar energy efficiency.

Removal of Acid Gases from Methane-Containing Gas Mixtures by Membrane-Assisted Gas Absorption. Hollow-Fibre Module Configuration with Absorption System Based on Dimethyldiethanolammonium Glycinate

The present study is focused on continuing the development, improvement and optimisation of a new hybrid separation method – membrane-assisted gas absorption, which is designed for processing methane-containing gas mixtures, namely for the removal of acid gases. The second part is devoted to the design of absorbent solutions and their application in the proposed technology in order to improve the efficiency of acid gas removal and reduce hydrocarbon losses. Absorbents of acid gases based on aqueous solutions of methyldiethanolamine containing ionic liquid [M2E2A][Gly] have been proposed and investigated. As a result of the study, the optimal absorbent composition for further separation tests in a membrane-assisted gas absorption unit was determined. The efficiency of the process was investigated on the example of 8-component gas mixture containing methane, ethane, propane, n-butane, nitrogen, carbon dioxide, hydrogen sulfide and xenon. The membrane-assisted gas absorption unit demonstrated high efficiency of acid gas removal and high hydrocarbon recovery. The final efficiency of the investigated system with the new absorbent was up to 99 % for acid gas removal with hydrocarbon losses of up to 1 % at maximum capacity.

ABSORPTION REFRIGERATION SYSTEMS FOR WASTE HEAT RECOVERY AT THE SILICATE INDUSTRY

The glass, ceramic and cement plants are energy intensive industrial systems, releasing high amounts of greenhouse gases. The dissipation of the waste heat reduces their profitability, energy and ecological efficiency. The absorption refrigeration systems are successful solutions for the recovery of thermal energy at different temperature levels to obtain useful cooling and heating powers for technological needs, and for air conditioning of administrative and industrial buildings. Although the absorption units in a heat pump and refrigeration cycle are currently used in building and industrial systems, they have not yet penetrated widely into the silicate factories. This paper discusses possibilities for the applications of basic types of absorption cycles at heat pump and refrigeration modes to utilize waste energy at different temperature levels in glass, ceramic and cement plants. The examined variants are demonstrated via examples, diagrams and analyses of the possible energy saving.

Mung bean protein enhances the expansion of corn starch during twin-screw extrusion.

This study examined the effects of the inclusion of mung bean protein (MBP) on the direct expansion characteristics of corn starch during twin-screw extrusion. Six blends of corn starch and MBP isolate (0%, 5%, 10%, 15%, 20%, and 25% w/w) were hydrated to three different moisture contents (MCs) (16%, 19%, and 21%w.b.). The blends were extruded using a twin-screw extruder at three screw speeds (SSs) (300, 400, and 500rpm). The resulting extrudates were evaluated for their water solubility index, water absorption index, expansion ratio (ER), true density, unit density, and porosity. As the protein content increased, the porosity of the extrudates increased. The ER of all extrudates ranged from 2.90 to 5.46, with the largest ER observed at an SS of 400rpm, an MC of 19%, and 25% MBP inclusion. The porosity of the extrudates ranged from 1.79% to 11.42%. SS and protein content had a significant impact (p<0.05) on the porosity and ER of the extrudate. PRACTICAL APPLICATION: This work provides valuable information for the industry on utilizing mung bean protein in direct expanded corn starch-based extruded snacks. The information could be useful in the development of high-protein extruded snacks and breakfast cereals.

Growth performances of Clarias gariepinus juveniles fed with Jatropha curcas seed meal

Growth performances of Clarias gariepinus juveniles fed with Jatropha curcas seed meal

Fabrication and characterization of novel high-efficiency and high-durability neutron-absorbing Ni-based alloys

Fabrication and characterization of novel high-efficiency and high-durability neutron-absorbing Ni-based alloys

Study on low-mid-frequency broadband sound absorption properties of bending acoustic metamaterials with embedded porous materials

With the rapid development of the traffic industry, noise issues are becoming increasingly serious, and the traditional noise control technologies have the problems of poor low-frequency noise absorption and narrow bandwidth. This study proposes a variable-section bending acoustic metamaterial with an embedded porous material (VS_BAMP). A theoretical model of the VS_BAMP unit is developed based on the Johnson-Champoux-Allard (JCA) model and the impedance transfer method. The sound absorption unit with a thickness of 48 mm exhibits a quasi-perfect (α = 0.98) at 736 Hz, and an efficient sound absorption (α > 0.8) in the range of 574 Hz–966 Hz. Based on the complex frequency plane method, this work designs sound absorption units that exhibit perfect sound absorption at discrete frequencies. By connecting two different absorption units (PVS_BAMP) in parallel, efficient sound absorption from 424 Hz to 1500 Hz is achieved. Finally, the accuracy of the theoretical model is verified by experiments and simulations, confirming the effective sound absorption of PVS_BAMP structure in the middle and low frequency bands. The prepared PVS_BAMP is highly adjustable, has a wide bandwidth, and can be prepared through a simple manufacturing process. Our results can provide a theoretical basis for the design of compact low-mid-frequency broadband noise reduction structures for practical application.

ON FEASIBILITY OF AZEOTROPIC SYSTEM USING TO IMPROVE DIETHYLENE GLYCOL REGENERATION QUALITY

The main technological scheme for dry natural gas treatment is absorption drying with diethylene glycol (DEG) vacuum regeneration. The final stage of field development is characterized by low flow rates and high moisture content of the gas, leading to load increase on gas drying devices and the DEG regeneration unit, resulting in deterioration in the quality of the regenerated DEG. This is due to DEG contamination with mechanical impurities, organic salts, products of its resinification and decomposition.In conditions of declining gas production at the fields of the Cenomanian deposits of theFar North, one of the possible variants of DEG regeneration processes efficiency increasing is the transfer of glycol regeneration units to operate according to the azeotropic distillation scheme.The objects of the study are water-saturated glycol regeneration units used in absorption units of gas fields. The issues of technological efficiency of water-saturated glycol regeneration unit operation according to existing schemes are considered and feasibility of their transfer to the use of azeotropic distillation is given.

Corrosion behavior of new nuclear shielding Ni–Cr–W–Gd alloys in simulated spent nuclear fuel pool water

Corrosion behavior of new nuclear shielding Ni–Cr–W–Gd alloys in simulated spent nuclear fuel pool water

Innovative and efficient integrations of desalination plants coupled absorption, adsorption, and humidification-dehumidification desalination units employing external heat recovery techniques

Innovative and efficient integrations of desalination plants coupled absorption, adsorption, and humidification-dehumidification desalination units employing external heat recovery techniques

Novel working fluid pair of methanol/betaine-urea for absorption refrigeration system driven by low-temperature heat sources

Novel working fluid pair of methanol/betaine-urea for absorption refrigeration system driven by low-temperature heat sources

Efficiency enhancement in solar energy storage: Impact of oval inner tube geometries on phase change material units

This comprehensive study systematically investigates the melting and solidification processes in phase change material (PCM) units, specifically comparing different inner tube geometries, including horizontal oval, inclined oval (45°), and vertical oval, against the circular inner tube. Through meticulous analysis, the study reveals that the vertical oval inner tube demonstrates superior efficiency, achieving complete melting and solidification in significantly shorter times compared to other geometries. In the melting process, the unit with a circular inner tube completes melting at 7560 s, the horizontal oval and inclined oval units complete at 7500 s, and the vertical oval unit completes at 7260 s. Notably, the reduction in melting time for horizontal oval and inclined oval units is approximately 0.8%, while for vertical oval unit, it is notably greater at 3.96%. Similarly, in the solidification process, the unit with the circular inner tube completes solidification at 17760 s; the horizontal oval completes at 17160 s, the inclined oval unit completes at 16080 s, whereas the vertical oval unit completes at 14400 s. The reduction in solidification time for the horizontal oval and inclined oval is 3.37% and 9.46%, respectively, whereas for the vertical oval, it is notably greater at 18.91%. These findings underscore the profound influence of inner tube design on heat absorption, temperature profiles, and overall PCM unit performance. The substantial reductions in both melting and solidification times, particularly for the unit with a vertical oval inner tube, highlight the critical role of inner tube geometry in optimizing PCM efficiency and responsiveness to thermal changes.