Bed System Research Articles

Who gets the bed: Factors influencing the intensive care exit block - A qualitative study

BackgroundPatient flow problems, including discharge delay and after-hours discharge, have been a consistently major issue, especially for intensive care units (ICUs). Evidence suggests that discharge delay and after-hours discharge are associated with increased ICU and hospital length of stay, leading to worsened patient outcomes and increased healthcare costs. They can also increase ICU readmission and post-ICU mortality. The factors influencing discharge processes are not well elucidated. ObjectiveThis study aimed to explore the barriers and facilitators to the ICU patient discharge processes in adult ICUs. MethodsThis qualitative exploratory multisite observational study was conducted in three regional adult ICUs in Queensland, Australia. We used staff interviews, fieldnotes, and document analysis as data collection techniques. Data analysis commenced with a deductive content analysis using the Structure, Process, and Outcomes framework. Following this, an inductive process was taken using the Theoretical Domains Framework. FindingsWe conducted 59 staff interviews and analysed the discharge documents across three sites. Five domains, including context and resources, beliefs about consequences, social/professional role and identity, and behaviour regulation, were strongly related to the factors that influenced the discharge processes. The findings revealed barriers to discharge, including finding the right bed, disconnected and ineffective information systems, ineffective communication and coordination within and across teams and departments, and uncertainty and inconsistency in discharge decision making. Facilitators included clarity on professional roles in ICU discharge, effective communication within the ICU team, and context specific strategies to support the discharge processes. ConclusionsThe findings provide an in-depth understanding of the barriers and facilitators to the ICU discharge processes. Multifaceted strategies should be considered to facilitate and manage ICU discharge safely and efficiently, including the use of clearer discharge criteria and guidelines, digital systems that aid communication and coordination, and early planning of ICU patient discharge.

Capture and catalytic conversion of CO2 from marine and offshore applications – A review

Abstract This contribution examines recent advances in modeling fluid dynamics and capture/conversion of CO2 from marine and offshore applications in packed-bed columns/trickle-bed reactors subjected to static inclination, externally-induced rolling and heaving motions. Breaking the axial symmetry of the two-phase flow once the packed bed system is tilted results in a significant decrease in process performance, the extent of which is determined by the magnitude of the tilt and the column/reactor diameter. Only the conversion of CO2 from marine engine emissions on-board large cargo ships via catalytic cycloaddition of CO2 to styrene oxide in multiphase large-diameter trickle-bed reactors increases slightly with increasing reactor inclination. Under the externally induced column/reactor oscillations, CO2 capture/conversion performance shifts toward the steady-state solution of the vertical column/reactor as the asymmetry between the two inclined positions decreases. Oscillating (between two inclined symmetrical positions) and heaving packed-bed columns/trickle-bed reactors generate an oscillating performance around the steady-state solution of the vertical static position, which is driven by the amplitude and period of the angular and heaving motions via the continuous evolution of the intensity of the reverse secondary flow and by the magnitude of the reactor/column diameter. The catalytic conversion of CO2 captured from marine emissions via an integrated process coupling reverse water-gas shift reaction and methanol synthesis in a fixed-bed reactors network system shows a remarkable enhancement with the addition of H2O adsorbent to the reaction systems in the sorption-enhanced process periods.

Nitrous Oxide Emissions in Aquaponic Systems: a Systematic Review

Objective: The study sought to analyze work related to the aquaponics system and the emission of this greenhouse gas. Initially, 143 articles were selected, resulting in 14 final articles, using the PRISMA protocol. Result and Discussion: The study concluded that further research is needed to increase the efficiency of Nitrogen use and reduce denitrification, since these variables are directly related to the emission of N2O and its consequent harmful effects on the environment. The cultivation systems evaluated had the following distribution: The Cultivation Bed system represents 60% of the studies, followed by the DWF - Deep Wather Culture system with 26.7% and the NFT - Nutrient Film Technique system with 13.3% of the samples evaluated

Improved catalytic stability of immobilized Candida antarctica lipase B on macroporous resin with organic polymer coating for biodiesel production.

Lipase is one of the most widely studied and applied biocatalysts. Due to the high enzyme leakage rate of the immobilization method of physical adsorption, we propose a new lipase immobilization method, based on the combination of macroporous resin adsorption and organic polymer coating. The immobilized Candida antarctica lipase B (CALB@resin-CAB) was prepared by combining the macroporous resin adsorption with cellulose acetate butyrate coating, and its structure was characterized by various analytic methods. Immobilized lipase was applied for biodiesel production using acidified palm oil as the starting material, the conversion rate achieved as high as 98.5% in two steps. Furthermore, the immobilized lipase displayed satisfactory stability and reusability in biodiesel production. When the aforementioned reaction was carried out in a continuous flow packed bed system, the yield of biodiesel was 94.8% and space-time yield was 2.88g/(mL∙h). The immobilized lipase CALB@resin-CAB showed high catalytic activity and stability, which has good potential for industrial application in the field of oil processing.

Development and characterization of mesoporous silica-MgSO4-MgCl2 binary salt composites for low-grade heat storage in fluidized bed systems

Achieving nearly zero-energy buildings requires the efficient utilization and storage of renewable energy. Salt-hydrate-based thermochemical energy storage (TCES) systems are promising due to their high heat storage capacity and minimal seasonal heat loss. However, challenges remain in their commercialization and large-scale application. For instance, TCES systems using magnesium sulphate (MgSO4) provide low temperature lifts due to slow reaction kinetics. Incorporating deliquescent salts like magnesium chloride (MgCl2) can enhance sorption performance but may introduce stability issues such as agglomeration and decomposition. This study presents a novel binary-salt composite combining MgSO4 and MgCl2 within commercial mesoporous silica (CMS) to address these challenges and enhance overall performance. The binary-salt composite powder, with a particle size range of 150–300 μm, is well-suited for use in fluidized-bed reactors, where fast mass and heat transfer promote efficient moisture adsorption, prevent uneven temperature distribution, and reduce agglomeration. Thermogravimetric analysis (TGA) was employed to evaluate the water sorption and desorption behaviour of MgCl2-MgSO4@CMS binary-salt composites with a total salt content of 50 wt% and salt mixing ratios of 3:1, 1:1, and 1:3. The corresponding water sorption capacities were 0.95, 0.68, and 0.57 g/g, respectively. In comparison, the MgSO4@CMS single-salt composite showed a lower water adsorption capacity of 0.47 g/g and required temperatures exceeding 150 °C for complete regeneration. Reactor-scale experiments demonstrated that the MgCl2-MgSO4@CMS composite with a 1:1 salt mixing ratio could be fluidized at low gas velocities on the order of 10−2 m/s, achieving a maximum temperature lift of 24.7 °C and an energy density of 1018 kJ/kg during hydration at 80% relative humidity and 30 °C. Additionally, the binary-salt composite showed good cyclic stability with less particle agglomeration compared to the MgCl2@CMS single-salt composite.

Numerical simulation of granular heat transfer within lifter rotating drum using smoothed particle hydrodynamics (SPH)

Abstract The rotating drums are typical industrial thermal processing equipment, which is widely used to heat or cool material particles in the circle fluid bed (CFB) systems. The traditional cylindrical rotating drum cannot significantly promote the heat transfer process of granules in operation, largely limiting further application. In this research, using smoothed particle hydrodynamics (SPH), two different types of lifters are employed to investigate the effects of shape, size, and number of lifters on the coefficient of heat transfer within the rotating drums by combining the flow and mixing characteristics of particles, the stress distribution, the transient velocity and temperature distribution, and the trend of the Peclet number.

A CFD and experimental study of hydrodynamic and heat transfer behavior in ribbed fluidized beds

Abstract The study focuses on enhancing the performance of fluidized bed systems, which are widely used in industrial processes requiring efficient heat and mass transfer. By integrating ribs at angles of 135, 150, and 165° on the riser wall, the research assesses their impact on hydrodynamic behavior and heat transfer using CFD simulations. The simulations, confirmed through experimental data, revealed that the 150° ribbed model outperforms others by improving particle mixing and achieving the highest heat transfer coefficient. The investigation also covered static pressure, solid volume fraction, and particle velocities at different bed heights (30, 60, 90, and 120 mm), showing that ribbed models significantly enhance turbulence and particle distribution, with the 150° ribs providing a balance between dynamic mixing and stable flow.

Performance assessment of packed bed systems for humidity control in greenhouse applications: An experimental based AI modelling approach

Optimal humidity control is essential for enhancing crop yields and ensuring favourable growth conditions in greenhouse agriculture. Packed bed devices are effective tools for regulating humidity levels; however, accurately assessing their performance, especially for temperate oceanic climates, is yet explicitly unexplored. The current paper presents a packed bed system using water as the working fluid to increase humidity during winter for greenhouse cultivation. An experimental setup is developed, and a detailed parametric study is conducted. Also, an artificial intelligence (AI) based multi-layer perceptron neural network (MLPNN) is designed to evaluate the performance of packed bed systems under varying environmental conditions with different inlet air flow rates (176 m³/hr, 286 m³/hr, 383 m³/hr, and 428 m³/hr). The results show that the system achieves a significant 50% increase in humidity ratio, transitioning from an inlet humidity ratio of 6 g/kgda to an outlet ratio of 9 g/kgda when operating with water at an average temperature of 15.7°C and a flow rate of 12.8 kg/min. The MLPNN is trained with 112 non-repeated datasets and observed that a topology of 2-10-10-1 includes 2 input neurons, 2 hidden layers with 10 neurons each, and 1 output neuron, has high prediction accuracy in estimating Δωa values for the packed bed system. The predictions closely align with experimental data, showing a maximum discrepancy within ±2.5%. This research advances the use of packed bed systems by providing a comprehensive framework for assessing and improving humidity control in greenhouse environments.

Performance assessment of packed bed systems for humidity control in greenhouse applications: An experimental based AI modelling approach

Optimal humidity control is essential for enhancing crop yields and ensuring favourable growth conditions in greenhouse agriculture. Packed bed devices are effective tools for regulating humidity levels; however, accurately assessing their performance, especially for temperate oceanic climates, is yet explicitly unexplored. The current paper presents a packed bed system using water as the working fluid to increase humidity during winter for greenhouse cultivation. An experimental setup is developed, and a detailed parametric study is conducted. Also, an artificial intelligence (AI) based multi-layer perceptron neural network (MLPNN) is designed to evaluate the performance of packed bed systems under varying environmental conditions with different inlet air flow rates (176 m³/hr, 286 m³/hr, 383 m³/hr, and 428 m³/hr). The results show that the system achieves a significant 50% increase in humidity ratio, transitioning from an inlet humidity ratio of 6 g/kgda to an outlet ratio of 9 g/kgda when operating with water at an average temperature of 15.7°C and a flow rate of 12.8 kg/min. The MLPNN is trained with 112 non-repeated datasets and observed that a topology of 2-10-10-1 includes 2 input neurons, 2 hidden layers with 10 neurons each, and 1 output neuron, has high prediction accuracy in estimating Δωa values for the packed bed system. The predictions closely align with experimental data, showing a maximum discrepancy within ±2.5%. This research advances the use of packed bed systems by providing a comprehensive framework for assessing and improving humidity control in greenhouse environments.

Performance Evaluation of Hydroponic Grow-Outs in An Innovative Coldwater Aquaponic System Featuring Rainbow Trout and Lettuce

A 45-day trial was carried out to assess the production performance of different hydroponic media in a novel do-it-yourself (DIY) low-tech re-circulating aquaponic system for temperate regions with rainbow trout (Oncorhynchus mykiss) and lettuce (Lactuca sativa). Rainbow trout juveniles (average weight of 35.59 g) were stocked in the experimental units at 2.8 kg.m-3 and fed with commercial floating pelleted feed at 8 % of their body weight in three treatments and a control. The lettuce saplings were randomly planted in the river stone bed (T1), crushed stone bed (T2), raft/deep water culture (DWC) unit (T3) and control (C) soil bed (fortified with NPK fertiliser) with equivalent planting intervals of 42 saplings.m-2. The system, designed with low-tech simplicity, was managed without alkalinity correction and depended entirely on plant growth and metabolism for biofiltration. The water quality parameters such as temperature, pH, dissolved oxygen (DO), dissolved free CO2, hardness, total alkalinity, ammonium, nitrite, and nitrate varied significantly (P < 0.05) among the treatments compared to the control. The final individual weight, biomass gain, specific growth rate (SGR), and feed conversion ratio (FCR) of rainbow trout were significantly better (P < 0.05) in media beds (crushed stone and river stone) compared to control and DWC systems. The final mean weights of rainbow trout in river stone (12.33 ± 0.002 g and crushed stone (12.39 ± 0.054 g) treatments were significantly higher (P < 0.05) than in DWC (12.1 ± 0.023 g) and control (12.09 ± 0.002 g) treatments. The production of lettuce was significantly greater (P < 0.05) in all three treatments (river stone: 4.33 ± 0.123 g, crushed stone: 4.53 ± 0.09 g and DWC: 4.31 ± 0.163 g) compared to the control (3.31 ± 0.172 g). The DWC including the media bed systems facilitates the improved performance of lettuce saplings in terms of final height and leaf number. These results show that a low-tech media bed system without a supplementary biofiltration unit can achieve sustainable production of both fish and vegetables in temperate hilly terrains.

Development of a circulating fluidized bed for a 100 kg/day waste plastic pyrolysis-combustion system

The aim of this study was to develop a 100 kg/day plastic waste pyrolysis-combustion circulating fluidized bed (CFB) system. The CFB was designed to provide heat from the combustor (semi-riser type) to the pyrolyzer (bubbling fluidized bed (BFB)) through heat carriers in high efficiency. A 100 kg/day scale system, including an oil condensation facility, was constructed and operated continuously for 34.5 hrs. Pelletized polypropylene was supplied to the pyrolyzer as plastic waste. The temperature in the pyrolyzer and plastic feeding rate were experimental variables. The weight percentage of low (C1–C12) and middle (C13–C22) carbon number components of the produced oil in CFB operated at 512-551 °C was 65.3 and 23.2 %, respectively. These were significantly higher than 34.6 and 28.4 % of the BFBs with similar temperatures previously, implying that the heat transfer in the CFB was more intense than that in the BFB. Compared to the BFB, only subtle differences in the pyrolysis gas yield was observed for CFB, which signified that the gas mixing between two reactors was minimized during the operation. Although no blockage was found in the CFB, clogging of condensers and pipelines occurred during low-temperature operation owing to the relatively low pour point of the product oil. The results in this study provide detailed and practical information on the temperature, pressure, product gas, oil, and clogging issues to better understand plastic pyrolysis in CFB.

Comparison of the pyrolysis behavior of PC, ABS and PC/ABS

Three types of plastics—polycarbonate (PC), acrylonitrile-butadiene-styrene (ABS), and PC/ABS blend—were studied in this work. Kinetic analyses were performed using the Flynn-Wall-Ozawa (FWO) and Kissinger–Akahira–Sunose (KAS) methods. The evolved volatiles during the pyrolysis of each material were analyzed, and the pyrolysis behavior was proposed using in-situ tools such as thermogravimetric analyzer-Fourier transform infrared spectroscopic (TG-FTIR) and gas chromatographic separation and mass spectrometry detection (Py-GC/MS). The three samples were also pyrolysed in a fixed bed reactor to elucidate the impact of secondary reaction. For PC, the activation energy increases as the reaction progresses. PC primarily generated CO2 and oxygenated compounds. For ABS, the activation energy experienced a slight decrease once the depolymerization reaction initiates, while a reversed trend can be observed at higher conversion rates. ABS pyrolysis mainly produced nitrogen-containing compounds and mono-aromatics. In the case of PC/ABS blend, a distinctive two-stage decomposition mechanism was observed. The interaction between PC and ABS in the blend promoted the formation of N/O-containing compounds. Additionally, this interaction enhanced the production of lighter phenols at the expense of bisphenol A, while ABS was not affected markedly. Stronger re-condensation and cracking reactions in the fixed bed system, facilitated the formation of poly-aromatics and lighter phenols (p-cresol and 4-ethylphenol) at the expense of bisphenol A during the pyrolysis of PC. In contrast, styrene from ABS decomposition was weakly affected by the secondary reaction. The intensified secondary reactions occurring the sample bed of the fixed bed experiments can also enhance the interaction between volatiles from ABS and PC, forming more heterocyclic N-compounds.

PSLBII-23 Effects of alternative production systems on growth and circulating blood profiles in Berkshire grower pigs

Abstract In this study, we compared the growth performance and circulating blood profiles of Berkshire grower pigs maintained in two different alternative swine production systems, the dry-lot production system, and the hoop structure production system. This study was conducted during a 75-d period spanning from May to July at the North Carolina Agricultural and Technical State University Swine Facility in Greensboro, N.C. Protein expression profiles associated with growth (FGF-19, PDGF-BB, IGF-1), feed intake (CCK), stress (cortisol) and the ability to handle oxidative stress (T-AOC) were analyzed in blood plasma obtained from 24 Berkshire nursery/grower pigs. Berkshire pigs (n = 12) were managed in a 12.19 m x 18.28 m hoop structure with the end walls removed for ventilation and a straw deep bedding system. Twelve additional Berkshire nursery/grower pigs were managed in a 0.08-ha dry-lot. These animals were provided with a canopy for shade and a wallowing area for evaporative cooling. All animals were provided with ad libitum ration and water. Individual body weights (BW) and blood samples were collected at 25-d intervals throughout the 75-d trial, culminating in three different time points. Plasma was isolated from the blood samples and used for ELISA and colorimetric assays. The BioTek 800 TS absorbance reader and Gen5 Microplate Reader and Imager software (Agilent Technologies, Inc., Santa Clara, CA) were used to obtain and calculate the optical densities of the plasma samples, respectively. The data were analyzed using the two-way ANOVA feature of JMP 17.2.0 software (SAS Institute, Inc., Cary, NC) with production system and growth period considered fixed variables, while either growth rate or protein concentration were considered as the response variable. There were four significant treatment effects observed (P < 0.05). Significantly greater concentrations of IGF-1, CCK, and T-AOC were detected in the plasma collected from Berkshire pigs managed in the dry-lot. Whereas those managed in the hoop structure production system had heavier BW. The results show that exposing pigs to higher temperatures can reduce feed intake and growth rates. However, this same stress elicits the release of hormones that promote growth, while enhancing the total antioxidant capacity in these animals. The results support the adoption of the hoop structure production system over the dry-lot production system when managing swine in regions that experience higher temperatures.

Efficient chromium remediation using eco-innovative biochar in a novel two-stage upflow fixed bed system

Chromium (Cr) pollution poses a significant environmental threat. This study addresses the highly toxic hexavalent form of chromium [Cr(VI)] by developing an innovative two-stage upflow fixed-bed system. The system uses nano iron sulfide-modified biochar (nFeS-BC), derived from spent substrates of Lentinus edodes, as the primary adsorbent. The study determines the removal mechanisms by nFeS-BC, including ion exchange, functional group interaction, complexation and co-precipitation. Fixed bed experimental results demonstrated a maximum adsorption capacity (qe) of 2.751 mg·g−1 for Cr(VI) with an initial concentration (C0) of 20 mg·g−1, bed height (Z) of 10 cm, flow rate (Q) of 2 mL·min−1, and at pH 2. The adsorption process closely followed the Thomas and Yoon-Nelson models, confirming a high fitting accuracy (R2 = 0.997), which underscores the predictability and stability of nFeS-BC in dynamic flow conditions. Subsequent treatment in a second fixed bed, filled with cetyltrimethyl ammonium bromide-modified biochar (CTAB-BC), reduced the total Cr concentration to 0 mg·L−1. Furthermore, nFeS-BC retained 50 % of its initial adsorption capacity after five regeneration cycles. This study highlights the potential of nFeS-BC within a novel fixed-bed design for efficient and sustainable treatment of actual wastewater.

Solar methane pyrolysis in a liquid metal bubble column reactor: Effect of medium type and gas injection configuration

Solar methane pyrolysis in different molten media and reactor configurations was experimented to improve hydrogen production. Pure Sn, Ni0.18Sn0.82, Cu0.45Bi0.55, and KCl melts were compared at three different temperatures (1030–1130–1230 °C), and no significant difference was observed except for KCl and only at 1230 °C (XCH4 = 72 % vs. 57 % for pure Sn). This enhanced performance was attributed to possible carbon dispersion in the salt, which probably modified the physical properties and enhanced hydrodynamics. A porous quartz sparger (downward injection) did not significantly enhance the bubbles hydrodynamics, mainly because bubbles were trapped and coalesced below the sintered disc. A custom-made sparger (lateral bubbling) did not either improve conversion due to non-uniform pores. A sparger with an upward injection should be preferred to generate small bubbles with longer residence time. When a solid bed of tungsten carbide particles was placed around the injector, overlaid by molten tin, the conversion was improved even at a relatively low temperature (XCH4 = 17 % at 1030 °C). The immersed bed likely behaved as a porous device and increased the gas-solid surface contact. Combining particle bed and liquid bubbling system is very promising for further optimization of methane pyrolysis in molten media. The carbon collected above molten metals showed mostly a sheet-like structure with significant metal contamination. In case of KCl, most carbon was entrained with the gas, while the remaining was mixed with KCl in the reactor. The density of KCl is close to that of carbon, which prevented a good separation.

Enhanced performance of red mud oxygen carrier for chemical looping combustion via tandem reactions

Biomethane power generation, particularly chemical looping combustion technology, has garnered significant attention recently due to its ability to capture CO2 in situ. In this study, dual bed layers oxygen carriers (DBL) for chemical looping combustion of methane were designed. The LaFe0.93Ni0.07O3 oxygen carrier with excellent CH4 partial oxidation was applied in upper bed layer and low-cost red mud was located into lower bed layer. This tandem reaction showed much higher methane conversion (87.1 %) than that over the single oxygen carrier of red mud (33.9 %) and the mechanically mixed oxygen carrier of LaFe0.93Ni0.07O3 and red mud (77.7 %). In addition, the mechanically mixed sample showed a quick deactivation, with the methane conversion dropping 54.2 % after 40 redox cycles due to the encapsulation of the active LaFe0.93Ni0.07O3 by red mud, while the double bed system showed high stability in the long-term redox cycle. The limitedly increased crystallite size of LaFeO3, as well as completely replenished lattice oxygen, were responsible for superior activity and stability of DBL. This study provides a new strategy to improve the efficiency of chemical looping combustion of methane in fixed bed reactor by tandem reactions over different oxygen carriers with complementary functions in terms of activity and cost.

Spouting behavior of binary mixtures of spherocylindrical and spherical particles in a spouted bed

Gas-solid spouted bed systems involving biomass utilization have received much attention in recent years. In actual biomass industrial processes, some fine inert particles are usually added to assist the fluidization of biomass particles. However, the flow mechanisms of binary particle systems containing biomass particles in spouted beds are still poorly understood so far. In this study, spherocylindrical particles representing biomass particles and spherical particles representing inert particles were used as the objects of study. The macroscopic and microscopic flow characteristics were explored based on CFD-DEM modeling when the volume fractions of spherocylindrical particles in the binary particle mixtures were 25 %, 50 %, 75 % and 100 %, respectively. The results showed that the minimum spouting velocities (Ums) were in the range of 150–173 m/s, but did not show a correlation with the different particle systems. During fluidization in binary particle systems, separation of spherocylindrical and spherical particles occurs. There is no significant correlation between the particle systems with different volume fractions of spherocylindrical particles and particle orientation. As the volume fraction of spherocylindrical particles increases, the average bed height of the particles decreases and the translational kinetic energy of the particles decreases/rotational kinetic energy increases. Furthermore, the wall effect influences the spherocylindrical particle orientation and volume fraction, driving the spherocylindrical particles near the wall surface toward the vertical direction.

Using ligand regulation, metal replacement, and ligand doping strategies on Zr-FUM to improve methane separation from coalbed gas

Developing adsorbents suitable for industrial applications that can effectively enhance the separation of methane (CH4) from nitrogen (N2) in coalbed gas is crucial to improve energy recovery and mitigate greenhouse gas emissions. In this study, three modification strategies were implemented on Zr-FUM, including ligand regulation, metal replacement, and ligand doping, to synthesize Zr-FDCA, Al-FUM, and Zr-FUM-FA, with the aim of improving the performance of CH4/N2 separation under humid conditions. The results demonstrated that the promotion of robust orbital overlap and strengthened electrovalent bonding on adsorbents can selectively enhance CH4 adsorption. As a result, Zr-FUM-FA achieved a saturated CH4 adsorption capacity of 1.37 mmol/g, a CH4 working window of 307 s, and a CH4/N2 sorbent selection parameter (Ssp) of 47.31, exceeding the performance of most reported adsorbents. Analyses of the pore structure, surface morphology, and functional groups revealed that the presence of an ultramicropore proximity to CH4, reduced static resistance, and enhanced electrovalent bond were key factors for CH4 separation. Grand Canonical Monte Carlo and Density Functional Theory studies indicated that the introduction of -C-H- in FA played a crucial role in enhancing CH4 adsorption. Optimization of adsorption parameters using the Aspen adsorption package showed that in a dual-adsorbent bed system, the recovery and purity of CH4 in Zr-FUM-FA reach 99.5% and 97.3%, respectively, providing important theoretical support for the improvement of CH4 recovery in the pressure swing adsorption process from coalbed gas.

Bed, ridge and planting configurations influence crop performance in field-transplanted hybrid potato crops

Current cultivation practices for field transplanted potato crops grown from nursery-raised hybrid potato seedlings are mostly borrowed from the tuber-based conventional system. Most studies on field performance of field transplanted seedling crops have largely reported the use of ridged rows and in exceptional cases, the use of beds. It is therefore critical to assess the feasibility of the use of alternative ridge or bed systems for cultivation of field-transplanted nursery-raised potato seedlings considering the differences in physiological behaviour of crops grown from different starting materials. This study assessed the effects of six systems which included bed and ridge systems of different dimensions and planting configurations for field transplanted seedling crops. Field crop establishment, canopy growth and development as well as yield and yield components were assessed. In general, systems that boasted high plant densities resulted in faster canopy development and higher number of tubers and tuber yield. Bed systems (raised and flat beds; 8.0 plants m−2) therefore gave the highest numbers of tubers and tuber yield across all treatments. These systems also produced the most tubers in all tuber size classes resulting in the highest yields in all classes. Standard ridge systems (full- and half ridges; 0.75 m row distance), had the lowest plant populations (5.3 plants m−2) which resulted almost always in fewer tubers and lower yield. Other ridge systems (0.9-m and 0.5-m ridge systems), although having higher plant densities than the standard ridge systems (8.9 and 8.0 plants m−2, respectively) still performed poorer than the bed systems. The small and compact ridges in the 0.5-m ridge system and the compact arrangement of plants in the 0.9-m ridge system caused these effects. Conclusively, based on this study, productivity in field transplanting systems is highly influenced by plant density. Further, cultivation systems boasting higher planting densities should be recommended when the goal for production is to produce large quantities of seed tubers (> 35; ≤ 50 mm).

Experimental analysis on improving heat storage efficiency of high-temperature packed bed system using spherical capsules filled with MgCl2–KCl–NaCl/Al2O3 nanoparticles composite phase change material

While thermal energy storage (TES) systems are becoming crucial to the stable operation of solar power plants, molten salt packed bed thermal energy storage (PBTES) systems attracted widespread attention due to their wide operating temperature range and low cost. However, achieving high-efficiency thermal storage systems is still a datum challenge to meet the higher energy demand, as well as sustainable development and utilization of renewable energy systems. This study developed spherical capsules employing nanocomposite salts (MgCl2–KCl–NaCl/Al2O3 nanoparticles) as composite phase change materials to experimentally study the heat storage process of a high-temperature PBTES prototype experimental system. Also, the heat storage performance of the PBTES system under different operating conditions is further investigated. The results showed that the nanocomposite salt gradually melted along the flow direction of the heat transfer fluid by exhibiting three-stage characteristics including solid phase sensible heat, phase change latent heat, and liquid phase sensible heat. Also, the temperature difference inside and outside the capsules showed the characteristics of peak-trough-peak. The PBTES system reached a heat storage density of 1290.51 MJ m−3 at a thermal efficiency of 86.95 %. The average heat storage rate increased by 49.55 % and the heat storage time was shortened by 29.67 % when the blower speed was increased from 800 r·min−1 to 1200 r·min−1. The experimental results implied that the PBTES system encapsulating nanocomposite salts has excellent thermal performance. This study demonstrated solving the problems of insufficient thermal energy supply in time or space and improving energy utilization could result in a high-efficiency thermal storage system.