Structure Conditions Research Articles

Predictive Model for Cell Positioning during Periodic Lateral Migration in Spiral Microchannels.

The periodic lateral migration of submicrometer cells is the primary factor leading to low precision in a spiral microchannel during cell isolation. In this study, a mathematical predictive model (PM) is derived for the lateral position of cells during the periodic lateral migration process. We analyze the relationship of migration period, migration width, and starting point of lateral migration with microchannel structure and flow conditions and determine the empirical coefficients in PM. Results indicate that the aspect ratio of the microchannel and the Reynolds number (Re) are key factors that influence the periodicity of the cell lateral migration. The lateral migration width is jointly affected by Re, the cell blockage ratio, and the microchannel curvature radius. The inlet structure of the microchannel and the ratio of the cell sample to the sheath flow rate are critical parameters for regulating the initial position. Moreover, the structure of the pressure field at the inlet constrains the distribution range of the starting point of the lateral migration. Regardless of whether the particles/cells undergo 0.5, 1, or multiple lateral migration cycles, the lateral positions predicted by PM align well with the experimental observations, thus verifying the accuracy of PM. This research helps to elucidate the characteristics of periodic lateral migration of cells in spiral microchannels and can provide practical guidance for the development and optimization of miniature spiral microchannel chips for precise cell isolation.

Mobility of trace elements in a coastal contaminated site under groundwater salinization dynamics

Water pollution is a significant issue resulting from past long-term actions. The remediation projects carried out under law constraints for industrial plants, which have been the major contributors to environmental and water pollution, are currently providing a significant amount of data about contaminated soil, surface waters, and groundwater. Most of such plants worldwide are in coastal zones. Based on a significant amount of chemical and environmental data for a coastal contaminated site subject to variable groundwater salinization, this study aimed to understand the mobility of some trace elements because of coastal zone dynamics. Data concerned 688 groundwater samples, including As, Hg, Cd, Crtot, Cu, Ni, Pb, V, Se, Zn, pH, electrical conductivity, chlorides, total organic carbon and organic contaminants as quantitative variables, enhanced by additional qualitative variables such as groundwater salinity, season, water level, precipitation, and industrial activity type to make the dataset as representative as possible of the site under investigation. The study used robust multivariate statistical analyses to analyse the complex dataset and explain the relevant factors influencing contaminant behaviour under different environmental conditions. The Multivariate Statistical Analysis distinguished three clusters of trace elements with diverse reactivity to changes in groundwater salinization. The first includes Se, Cu, Crtot, V, and Ni, showing the highest correlation with electrical conductivity and chlorides because of their high affinity to form chloride or organic chloride complexes and for ion competition. Zn and Pb cluster in the second group: they are less reactive to groundwater salinization and more influenced by cation and anion competition and organic matter. The mobility of Hg and As (third cluster) significantly correlates with Fe and Mn, underlining the dominant role of reductive dissolution of trace elements-bearing minerals (Fe/Mn/Al-oxy-hydroxides) and metal-organic complexes. The correlation between the clustering of variables in groundwater and soils shows the influence of sediment structure, mineral composition, and physical and chemical soil conditions on the distribution in soils of trace elements and their transport to groundwater. The study proposes a valuable approach for assessing the effects of salinization in contaminated coastal aquifers. It supports planning multi-purpose characterization and monitoring campaigns of contaminated coastal sites and provides guidance on the correct associated remediation projects.

Exploring Platinum Thin Films as Electrodes for High‐Temperature and ‐Pressure Electrochemical Studies in Aqueous Systems

ABSTRACTThis work reports a methodology for the fabrication of Pt thin‐film electrodes for electrochemical studies in hydrothermal systems. The research process was meticulous, with particular attention paid to the multilayer Ti/Pt/Ti/Al2O3 film structure and annealing conditions that are expected to impact the morphology of the films, surface composition and electrochemical response. The findings of this study are significant, as they provide valuable insights into the behaviour of Pt thin‐film electrodes in various media and conditions. Two different approaches were adopted for the preparation of the electrodes: in one case, the Ti/Pt/Ti/Al2O3 films deposited on sapphire wafers were exposed to rapid thermal annealing at 900°C under argon for 5 min, followed by argon ion milling to etch the final electrode pattern (Pt‐RA(900)), while in the other case, uncapped Pt films were annealed, after etching, in a tubular oven under argon at specific temperatures between 200°C and 900°C (Pt‐TO). Rapid annealing at 900°C on capped films resulted in the formation of a Pt3Ti intermetallic alloy with remarkable mechanical and chemical stability even after 10 h of immersion in deionised water, acid (0.1 M H2SO4) and alkaline media (0.1 M KOH) conditions at temperatures up to 150°C, despite the dissolution of the Al2O3 top layer at 150°C and long immersion times (> 10 h). In the case of uncapped Pt films, diffusion and oxidation of Ti through the Pt film at high temperature resulted in the formation of TiO2 on the surface of Pt. The results were confirmed by using a comprehensive suite of ex‐situ characterisation techniques to follow changes in the Pt electrode surface morphology and composition before and after immersion in H2O, 0.1 M H2SO4 and 0.1 M KOH solutions under argon. Ex‐situ electrochemical characterisation studies were also conducted to correlate the changes in the electrode surface properties, including the electrochemical surface area, with different annealing conditions and after various hydrothermal treatments in neutral, alkaline and acidic media.

Expressions of the solenovian early oligocene crisis on the northern shelf of the Eastern Paratethys

The results of regional structure studies of the Solenovian deposits of the Eastern Paratethys Early Oligocene Rupelian Stage are presented. The geological structure and paleogeographic conditions that existed in the basin during the Solenovian time were refined on the base of complex interpretation of geological and geophysical materials. A spatial picture of the Eastern Paratethys sea level drops consequences during a series of regressions in the Oligocene period is traced. Shelf areas were periodically drained, which is reflected in the erosional unconformities structure and buried river incisions. It has been established that the most significant was the regression of the Late Solenovian time with a relative sea level drop amplitude of more than 500 m. As a result, a pronounced unconformity surface complicated by river cuts was formed inside the shelf part of the Maikop seismic complex. Erosion ledges and landslide bodies formed on the slopes, and basin-fill complexes accumulated in depression parts.

A N-heterocyclics induced π-π interaction strategy to synthesis hyper-crosslinked polymers with enhanced porosity for xenon adsorption

Hyper-crosslinked polymers (HCPs) with large specific surface areas play an important role in gas adsorption and separation. However, the method to enhance the specific surface area of HCPs and gas adsorption performance without changing the polyaromatic hydrocarbons (PAHs) monomer structure and reaction condition is still missing. Here, we present a general and facile N-heterocyclics induced π-π interaction strategy to increase the specific surface area of HCPs by simply adding N-heterocyclics during the Friedel-Crafts alkylation reaction. The specific surface areas of HCP (tetraphenylmethane based HCPs, TPMBPy-TCM) increased up to 7.78 times compared to the one without adding N-heterocyclics. The crosslinking and stacking of PAHs was influenced by the π-π stacking between the N-heterocyclic complexes and PAHs. More importantly, N-heterocyclics coordinated with Lewis acids have lower electron density and do not react with PAHs in the Friedel-Crafts alkylation reaction, which can be removed easily from HCPs. The HCPs obtained shown good xenon adsorption performance with Xe uptake of 3.63 mmol/g, which is the highest value for organic adsorbents reported in literature. This work provides new insight into the preparation of high-performance HCPs.

Stand Characteristics, Leaf Traits and Growth of Threatened Conifer Pilgerodendron uviferum (Cupressaceae) in Southern Patagonia, Argentina

Pilgerodendron uviferum is an endemic Cupressaceae of Patagonia (Argentina) that is restricted to a small group of individual trees, growing in isolated populations (relicts) along its distribution. The main objective was to evaluate the habitat, forest structure, leaf traits, leaf nutrient reabsorption and growth of four relicts (area between 0.3 and 0.86 ha) in the Santa Cruz province (Argentina) to improve the available information for forest conservation purposes. Principal components analysis was conducted to determine the separation between relict populations based on their ecological characteristics (individual and habitat levels). We found contrasting environmental and forest structure conditions among the four studied relicts. For example, two relicts associated with Nothofagus antarctica showed higher values of P. uviferum tree density, DBH and dominant height at the stand level. Alongside that, these relicts presented a higher sapling density (1950–3167 ind ha−1) and understory plant diversity compared to pure P. uviferum relicts growing near the ecotone with the steppe grassland. Specific leaf area, carbon and nutrient concentrations in P. univerum leaves varied depending on the relict conditions and tree age of the individuals. The mean nutrient resorption efficiency varied according to relicts and particular nutrients, ranging from 18.1% to 49.5% for Ca and P, respectively. The diameter growth of the dominant P. univerum trees ranged from 0.33 to 0.46 mm yr−1, indicating that the species follows a stress-tolerant strategy. The information of this work may assist in the conservation of marginal P. uviferum forest communities spatially disconnected with continuous forests, growing in relicts.

Novel dopant-free ferromagnetic Mott-like insulator and high-energy correlated-plasmons in unconventional strongly correlated s band of low-dimensional gold

Ferromagnetic insulators and plasmons have attracted a lot of interest due to their rich fundamental science and applications. Recent research efforts have been made to find dopant-free ferromagnetic insulators and unconventional plasmons independently both in strongly correlated electron systems. However, our understanding of them is still lacking. Existing dopant-free ferromagnetic insulator materials are mostly limited to complex d- or f-systems with extremely low Curie temperature, low-symmetry structure, and strict growth conditions on specific substrates, limiting their compatibility with industrial applications. Unconventional plasmon is, on the other hand, a quasiparticle that originates from the collective excitation of correlated-charges, yet they are rarely explored, particularly in ferromagnetic insulator materials. Herewith, we present a novel, room temperature dopant-free ferromagnetic Mott-like insulator with a high-symmetry structure in unconventional strongly correlated s band of low-dimensional highly oriented single-crystal gold quantum dots (HOSG-QDs) on MgO(001). Interestingly, HOSG-QDs show new high-energy correlated-plasmons with low-plasmonics-loss. With a series of state-of-the-art experimental techniques, we find that the Mott-insulating state is tunable with surprisingly strong spin-splitting and spin polarization accompanied by strong s–s transitions, disappearance of Drude response, and generating new Mott-like gap. Supported with a series of theoretical calculations, the interplay of quantum confinement, many-body electronic correlations, and hybridizations tunes electron–electron correlations in s band and determines the ferromagnetism, Mott-like insulator, and high-energy correlated-plasmons. Our result shows a new class of room temperature dopant-free ferromagnetic Mott-like insulator and high-energy correlated-plasmons with low-loss in strongly correlated s band and opens unexplored applications of low-dimensional gold in spin field-effect transistors and plasmonics.

Aero-thermodynamic responses of a novel FGM sector disks using mathematical modeling and deep neural networks

Composite sector disks have extensive applications in aerospace industries, particularly when exposed to challenging conditions such as supersonic airflow and thermal environments. These applications leverage the superior properties of composite materials, including high strength-to-weight ratios, enhanced durability, and excellent thermal resistance, to meet the stringent requirements of aerospace operations. Multi-directional functionally graded (MD-FG) materials due to high-temperature resistance and other amazing properties in each direction have gotten plenty of attention recently. So, in this research, a thermoelasticity solution has been presented to study fundamental frequency traits of an MD-FG sector disk in supersonic airflow via both mathematics simulation and deep neural networks technique. For obtaining exact displacement fields, along with defining the changes of transverse shear strains along the system's thickness, the refined zigzag hypothesis is utilized. For obtaining the temperature-dependent equations, heat conduction relation and thermal boundary conditions of the MD-FG structure are presented. A coupled quasi-3D new refined theory (Q3D-NRT) and generalized differential quadrature method (GDQM) are presented for obtaining and solving the partial differential equations in the time-displacement domain. After obtaining the mathematics results, appropriate datasets are made for testing, training, and validation of the deep neural networks technique. Finally, the results have shown that aerodynamic pressure, temperature changes, Mach number, free stream speed, and air yaw angle have a major role in the stability/instability analyses of the thermally affected MD-FG sector disk in supersonic airflow. As an amazing outcome, increasing the sector angle, FG indexes, and temperature change lead to the reduction of the critical Mach number, and aerodynamic pressure associated with the flutter phenomenon.

Hydrogeological conditions of the Meshchera depression and their connection with the latest tectonic structure of the region

The article presents the results of a study of the geological structure, recent tectonics and hydrogeological conditions of the central part of the Meshchera depression, located on the border of the Moscow, Ryazan and Vladimir regions. The detailed characterization of the newest structure of the Klepikovsky trough made it possible to identify young growing uplifts that influence the structure and morphology of the trough. The reasons for the intense swampiness of the territory and the change in the orientation of the trough from meridional to latitudinal are determined. The studies carried out proved the influence of the latest tectonics of the trough on the hydrogeological conditions of the territory. It has been established that areas of groundwater recharge and discharge can be localized within the Klepikovsky trough.

Tradeoffs between Stand Volume and Understory Vegetation Diversity in Quercus wutaishanica Forests under Climate Change

Natural forests play a crucial role in providing various ecosystem services, including timber production and biodiversity conservation. However, climate change and anthropogenic factors pose a severe threat to competing forest ecosystem services functions. Therefore, to optimize and sustainably utilize competing forest services, tradeoffs are often necessary. This study was conducted in Northwest China to explore tradeoffs aimed at improving the quality of Quercus wutaishanica Mayr natural forests under climate change conditions, focusing on stand volume, timber production, and understory vegetation diversity conservation. Data from 77 field surveys were used to construct a coupled model for stand growth, stand structure, and site conditions. Changes in understory vegetation species number (UVSN) with crown cover were quantified. These models and relationships can be used as tools to estimate tradeoffs. As stand density increased, single-tree volume decreased, whereas timber volume increased. UVSN increased and then decreased with increasing crown cover and was able to maintain a relative maximum at 0.5–0.65. Under the current climatic conditions, the optimum stand densities corresponding to 30, 40, 50, and 60 years were 1390, 1153, 1042, and 871 trees/ha, respectively, to maintain a high UVSN and adequate stand volume. When mean annual temperature rose, stand densities could be reduced to maintain high-quality timber. Although only two major services were considered, the tradeoffs presented in this study can inform future research to improve the quality of natural forests.

Farm dams: A valuable interim step in small‐bodied threatened fish conservation

AbstractFreshwater fish are facing an extinction crisis on a global scale, with increasing demand for human water consumption driving the regulation and degradation of freshwater ecosystems. Flow regulation especially poses a threat to small‐bodied floodplain and creek specialist species through increasing population fragmentation and isolation, loss and degradation of habitats, and interactions with predators and competitors, resulting in reductions in species' range and abundance. Conserving and recovering many small‐bodied fish species will likely require translocation from wild habitats to refuge habitats to reduce extinction risk and provide buffers against catastrophic natural events (e.g., drought, bushfires). We assessed the value of semi‐artificial farm dams, an abundant feature in the Australian landscape, as interim refugia for the threatened southern pygmy perch Nannoperca australis (Percicthyidae). We compared the relative abundance, population size–structure and body condition of fish introduced (3–4 years prior) into three farm dams with those of three nearby creeks to assess the feasibility of farm dams as a resource to assist small‐bodied native fish conservation and recovery. Farm dams had higher abundance of fish, and equivalent size structure and body condition compared with creek populations, highlighting that suitable farm dams are a valuable and underutilized asset for threatened species' conservation globally.

Sintering Driven Void Formation in PS@WO3 Core-Shell Composites: A Photodegradation Enhancement Strategy

Background: Polystyrene nanospheres are used as a substrate for the hydrothermal coating of tungsten trioxide (WO3) to form a core-shell composite of PS@WO3. The core-shell structure is used for the next sintering step. This produces porous WO3. The focus of this study is on the role of porous WO3 in enhancing photocatalytic performance. Methods: The hydrothermal method was employed for coating, and the surface morphology, as well as the structural properties of WO3-coated PS spheres, were systematically investigated using SEM and XRD analyses. Additionally, the sintering process was introduced to enhance the material by inducing rupture in the PS sphere core, creating voids that significantly increased the material's surface area. Results: The evaluation of the effect of sintering temperature on photodegradation efficiency highlighted the crucial role of sintering temperature. Un-sintered and 300°C sintered WO3, both having a hexagonal crystalline structure, exhibited superior degradation efficiencies compared to samples sintered at higher temperatures (400°C and 500°C). In particular, the 300°C sintered WO3 outperformed its un-sintered counterpart despite identical crystalline structures. The performance of the PS@WO3 composite was assessed to determine the enhanced role of porous WO3. The porous WO3 obtained, in particular by the sintering of the core-shell PS@WO3 composites at 300°C, showed a remarkable improvement in the degradation efficiency. These composite demonstrated over 95% efficiency within 10 minutes and achieved near complete (100%) degradation for a further 10 minutes, surpassing the performance of pure WO3. It is important to clarify that while the final product was predominantly WO3 after the sintering process, the inclusion of PS served a critical purpose in creating voids during sintering. The PS@WO3 composite structure used as a resource for the preparation of porous WO3, even with a potentially reduced PS composition, has been found to play a significant role in influencing the surface area of the material, and consequently the photocatalytic performance. Conclusion: The study has highlighted the importance of crystalline structure and sintering conditions in optimizing the efficiency of photocatalytic materials. The porous WO3 obtained, in particular by the sintering of the core-shell PS@WO3 composites at 300°C, showed promising potential for applications under UV and visible LED light irradiation. These results provide valuable insights for the development of advanced photocatalytic materials with improved performance, highlighting WO3 as the key contributor to the observed improvements.

Fault location method for new distribution networks based on waveform matching of time–frequency travelling waves

AbstractSome existing fault location methods for distribution networks rely too much on the local wave head information of the time or frequency domain signals, making it difficult to adapt to the increasingly complex structure and operating conditions of the distribution network after the new energy access. For improvement, the travelling wave (TW) time and frequency ranges that can effectively avoid waveform distortion caused by new energy access are analysed. The one‐to‐one matching relationship between the TW waveforms in these ranges and the fault positions is revealed. A fault TW time–frequency matrix with specific time and frequency windows is constructed, and a new distribution network fault location method is proposed based on the matching technique of waveform features, which realises the accurate fault location by exploring the proportionality between the cumulative trend of the matrix energy amplitude deviation and the fault point position. Simulation test results show that the proposed method is not affected by the complex structure of distribution networks such as new energy access and overhead‐cable line mixing on fault location and flexibly transforms the fault location problem into a time–frequency TW waveform matching problem, which improves the accuracy and robustness of the fault location for new distribution networks to a degree.

Effect of GDL Structure and Operating Conditions on PEMFC Performance and Liquid Water Removal

Gas diffusion layers (GDLs) in proton exchange membrane fuel cells (PEMFCs) are responsible for diffusion of reactant gases into the catalyst layers, current collection and the removal of produced water. An accumulation of generated liquid water within the GDL, known as flooding, impedes the supply of reactant gas and results in the increase of concentration overpotential. Therefore, understanding of oxygen transport and produced water removal characteristics is required to enhance cell performance. The objective of this study is to investigate the effect of GDL structure and operation conditions on PEMFC performance and liquid water removal, with a particular focus on comparing a novel GDL to a conventional GDL. The results of a simultaneous evaluation of cell performance and liquid water behavior in the GDLs by means of X-ray imaging under operational conditions are presented.

Effect of GDL Structure and Operating Conditions on PEMFC Performance and Liquid Water Removal

Gas diffusion layers (GDLs) in proton exchange membrane fuel cells (PEMFCs) are responsible for diffusion of reactant gases into the catalyst layers, current collection and the removal of produced water. An accumulation of generated liquid water within the GDL, known as flooding, impedes the supply of reactant gas and results in the increase of concentration overpotential. Therefore, understanding of oxygen transport and produced water removal characteristics is required to enhance cell performance. The objective of this study is to investigate the effect of GDL structure and operation conditions on PEMFC performance and liquid water removal, with a particular focus on comparing a novel GDL to a conventional GDL. The results of a simultaneous evaluation of cell performance and liquid water behavior in the GDLs by means of X-ray imaging under operational conditions are presented.

Simulation modelling demonstrates differential performance of connectivity methods in their ability to predict genetic diversity in complex landscapes

ContextThere have been few evaluations of how well different connectivity modelling methods are able to predict the spatial genetic structure and genetic diversity of populations residing in complex landscapes. Given the wide application of connectivity modelling tools in applied conservation planning, it is crucial to broadly evaluate how these models perform across resistance, movement, and population structure conditions in predicting genetic diversity patterns. Such evaluations are critical to provide rigorous, biologically based guidance for conservation and management applications. ObjectivesOur goal was to investigate how the predictions of three connectivity models were related to spatial patterns of genetic diversity complex landscapes, considering factors such as population structure, resistance, genetic drift, genetic disequilibrium, and organism movement abilities. MethodsWe evaluated the performance of several connectivity methods across seven a priori landscape resistance surfaces to provide a broad assessment of their performance. We used CDPOP, an individual-based, spatially explicit population and genetic simulation model, to simulate genetic diversity across these resistance surfaces. This provided a pool of genetic diversity patterns that were the response factor in our simulation experiment. We then simulated landscape connectivity with several popular connectivity methods, including resistant kernels, Circuitscape, and Pathwalker, and evaluated how well they were able to predict spatial patterns of genetic diversity. ResultsResistant kernel outperformed other connectivity methods in predicting landscape patterns of genetic diversity. The strongest relationships occurred when the population process has created spatial structure but has not yet led to significant genetic diversity loss due to drift. The time lag disequilibrium was relatively short. Long simulation times resulted in severe reduction in prediction ability due to drift. ConclusionsResistant kernel predictions were much more strongly related to spatial patterns of genetic diversity than were predictions produced by Circuitscape and Pathwalker, across a large combination of population structures. Strong relationships exist between functional connectivity and genetic diversity, with clearer and stronger associations seen in spatial patterns of allelic richness compared to heterozygosity or spatial effective population size. Our results confirm the strong relationship between genetic diversity and population connectivity, and suggest that computationally efficient incidence function algorithms, such as resistant kernel methods, are well suited to predicting functional connectivity.

Historical pyrodiversity in Douglas-fir forests of the southern Cascades of Oregon, USA

Our understanding of forest dynamics and successional pathways in coastal Douglas-fir (Pseudotsuga menziesii var menziesii) forests with relatively frequent mixed-severity fires is limited by a lack of annually precise dendroecological reconstructions that combine records of historical fires and tree establishment. The processes by which old-forest heterogeneity developed under historical fire regimes with recurrent low- and moderate-severity fires has not been well studied at fine temporal scales and across spatial scales. We developed crossdated multi-century records of fire and tree establishment histories in old forests (170 – 550 years) at 34 plots distributed across six sites. Study sites include warm-dry to cool-moist Douglas-fir forest types found in the southern west Cascades of Oregon, USA. Spatial variability in historical fire frequency and fire effects resulted in tremendous diversity in forest developmental histories, age structure, and forest conditions. Most historical fire intervals were very frequent (<10 years) to frequent (<25 years) in dry Douglas-fir forests. Exceptionally high fire frequency and an abrupt decrease in fire frequency after European colonization in dry Douglas-fir forests adds to growing evidence and recognition of Indigenous fire stewardship in montane Douglas-fir forests. In moist forests where Douglas-fir is seral to western hemlock, fire intervals were frequent to moderately frequent (<50 years), but intervals varied substantially over time. Relatively young moist forests burned frequently while mature moist forests had long fire intervals (50–160 years). Nearly all tree establishment cohorts were preceded by either stand-replacing (28 %) or non-stand-replacing fires (64 %). However, tree cohorts only provided evidence of 16 % of historical fire events that we reconstructed from cambial fire scars. This study demonstrates that frequent fire can be an important driver of forest development and in some contexts shapes the structure of coastal old-growth Douglas-fir forests, which are often characterized as developing from endogenous disturbances during long fire-free periods. The high level of pyrodiversity we observed was associated with variation in and interactions of micro-climate, topography, fuels, and Indigenous fire stewardship. We recommend rigorous dendroecological reconstructions across the coastal Douglas-fir region to refine our understanding of the geography of fire-mediated forest developmental dynamics in this important forest type, to inform forest management, conservation, and ecocultural restoration.

Quantifying the potential of load flexibility for building HVAC system using model predictive control strategy

Building as a Battery (BaB) is a concept aimed at utilizing building energy systems for load shifting purposes. However, there is a lack of study to accurately quantify building load flexibility and analyze how it is impacted by various factors. This study addresses this gap by first quantifying building load flexibility using battery parameters, specifically charging power, energy storage capacity, and round-trip efficiency. Subsequently, an analysis is conducted to examine the impacts of internal and external factors on building load flexibility, Specifically, we studied how ToU utility structure, load shifting duration, comfort range, ambient weather conditions, and building thermal properties influence charging power, energy storage capacity, and round-trip efficiency. Our simulation results revealed that an increase in the peak-to-valley ratio, load shifting duration, building thermal capacity, and cooling demand leads to higher charging energy and energy storage capacity, while an increase in building thermal resistance and widening of the comfort range result in their decrease. Regarding the round-trip efficiency, we found most parameters, except for building thermal capability, have a positive relation with the round-trip efficiency. Furthermore, sensitivity analysis showed that ToU utility structure and ambient weather conditions have the largest impacts on charging power, energy storage capacity, and round-trip efficiency. Additionally, our study indicates that leveraging buildings as virtual batteries for peak demand reduction is a feasible and cost-effective method compared with other energy storage techniques such as electric batteries. Overall, our findings offer valuable insights for parameterizing building load flexibility using battery parameters, analyzing factors that impact building load flexibility and informing grid operator to design property utility structures to meet their load shifting goals.

A Review on Liquid Hydrogen Storage: Current Status, Challenges and Future Directions

The growing interest in hydrogen (H2) has motivated process engineers and industrialists to investigate the potential of liquid hydrogen (LH2) storage. LH2 is an essential component in the H2 supply chain. Many researchers have studied LH2 storage from the perspective of tank structure, boil-off losses, insulation schemes, and storage conditions. A few review studies have also been published considering LH2 storage; however, most are simply collections of previous articles. None of these review articles have critically evaluated the research articles. In this review study, recent reports, conceptual studies, and patents have been included and critically discussed. Further, challenges and recommendations have been listed based on the literature review. Our results suggest that the multi-layer insulation scheme and integrated refrigeration system can effectively reduce boil-off losses. However, boil-off losses from storage tanks during transportation are the least discussed and must be addressed. The cost of an LH2 storage tank is high, but it can be reduced with advancements in materials and the utilization of latest technologies. The present challenges and future directions for LH2 storage include minimizing and utilizing boil-off losses, improving insulation schemes, and ensuring cost-effective large-scale LH2 storage. This review study can be fundamental for process engineers and new academic researchers to design energy-efficient and cost-effective LH2 storage systems.

THEORETICAL FRAMEWORK OF THE GREEN REGIONAL ECONOMY DOCTRINE FORMATION

This article explores the theoretical underpinnings of the green regional economy, a crucial concept within the broader framework of sustainable development, particularly in light of increasing global environmental challenges. The authors delve into the evolution of economic thought regarding the integration of environmental and economic objectives, highlighting the importance of balancing ecological sustainability with regional economic growth. The study identifies key factors and principles that underpin the green economy at the regional level, such as the efficient use of natural resources, the promotion of renewable energy, and the development of eco-friendly technologies. The article emphasizes the need to tailor global green initiatives to the specific needs and characteristics of individual regions, considering factors such as natural resource endowments, industrial structure, and socio-economic conditions. A significant focus is placed on the challenges of fostering environmentally sustainable economic development, with a particular emphasis on policy formulation that promotes ecological security and economic resilience. The article also discusses the role of green innovations, the mobilization of social capital, and regional governance in advancing the green economy. Furthermore, the authors propose a theoretical framework for the development of a green economy doctrine that incorporates key strategic initiatives, such as the transition to a circular economy, the integration of sustainability metrics into regional development plans, and the creation of green jobs. These elements are critical for fostering long-term ecological balance while ensuring economic growth and improving the quality of life at the regional level. The paper concludes with recommendations for further research and practical implementation of the green regional economy doctrine, underscoring the need for interdisciplinary approaches and collaboration between governments, businesses, and civil society to achieve sustainable development goals.