Island Formation Research Articles

Willingness to Pay for Lusi Island Ecotourism Development and Mangrove Conservation

Lusi Island is a small island formed from sedimentation at the estuary of the Porong River and has an area of 94 hectares on the border between Sidoarjo Regency and Pasuruan Regency. The mudflow dumped into the Porong River due to a mud volcano 15 years ago became the cause of the formation of the new island. The mangrove forest is one of the attractions of ecotourism on the island that could attract tourists. However, the determination of Lusi Island as a conservation area, and the increasing number of tourists do not damage the environmental sustainability of the island. Economic valuation could identify the interest and willingness of tourists to participate in preserving the mangrove forest on Lusi Island. The Contingent valuation approach is used to measure people’s preferences through direct interviews about how much respondents are willing to pay (WTP) to get an amenity and comfortable environment. The economic valuation method uses WTP (willingness to pay) as a technique for assessing the ability of tourists to contribute to the development of ecotourism. The results of this study become input in the development of ecotourism and mangrove conservation by considering the involvement of tourists in preserving Lusi Island.

Growth of Silicene by Molecular Beam Epitaxy on CaF2/Si(111) Substrates Modified by Electron Irradiation

For the first time, the possibility of producing silicene on CaF2/Si(111) substrates modified by electron irradiation is experimentally demonstrated. It is shown that areas of the planar surface of CaSi2 with hexagonal packing formed under an electron beam can be used as a natural template for the subsequent growth of silicene. Silicon is deposited on such surfaces and the formation of silicene islands is confirmed by atomic force microscopy and Raman spectroscopy.

Analysis of urban heat islands combining Sentinel 2 and Landsat 8 satellite images in Hochiminh city

Urbanization in big cities has led to many impacts, the most obvious of which is the increasing of impervious surfaces from urban areas, socio-economic construction, concrete roads and the reduction of green space (vegetation, water surface). The changes land use land cover (LULC) led to the changes in the land surface temperature (LST), the formation of urban temperature islands (UHI), which have changed the local climate. This study combined Landsat 8 and Sentinel 2 images to enhance the process and calculation of LST value, spatial resolution was improved to 10m compared to 30m when calculated by Landsat 8 image. In which, the study also used ArcGIS software to classify 4 land surface covers, namely built-up land, vegetation land, water surface and the other land in order to monitor the urbanization process (with kappa coefficients all over 0.8) and assess the trend of changing LST on each LULC in the period 2015 - 2022. The results showed that when combined with Sentinel 2 images, LULC such as built-up land, roads and vegetation cover were more prominent, helping to improve more accurate results when calculating LST. Besides the trend of urbanization development in Ho Chi Minh city, it also leads to changes in the distribution of UHI over time.

Seaweed diversification driven by Taiwan’s emergence and the Kuroshio Current: insights from the cryptic diversity and phylogeography of Dichotomaria (Galaxauraceae, Rhodophyta)

Ocean currents play a role in both facilitating and impeding connectivity of marine organisms’ populations, serving as key drivers and potential barriers. The emergence of Taiwan around five million years ago (Mya) impacted the Kuroshio Current which later shaped the distribution of marine organisms. In this study, we examined how the Kuroshio Current influenced the distribution and population divergence of the marine red alga Dichotomaria elegans (Galaxauraceae, Nemaliales). Through phylogenetic analysis, species delimitation, and morphological comparison of Taiwanese species, we determined its phylogenetic position relative to other species within the D. marginata complex of the genus Dichotomaria. We uncovered the hidden cryptic diversity within the D. marginata complex in Taiwan and proposed the new combinations D. elegans and D. latifolia based on Galaxaura elegans and G. latifolia. Genetic analysis based on three loci (mitochondrial cox2-3 and cox1, and plastid rbcL) from 32 locations across the Philippines, Taiwan, and Japan revealed three allopatric lineages within D. elegans. The first lineage is restricted to the northern Philippines and southern Taiwan, while the second has a broader latitudinal range along the Kuroshio Current. The third lineage is found in southeast Luzon, Philippines, close to the bifurcation of the North Equatorial Current, near the start of the Kuroshio Current. The divergence of the first two lineages during the mid-Pliocene (~3.7 Mya) coincided with the emergence of Taiwan, with the current dynamics accentuating their separation. The Kuroshio Current exhibited a dual impact on the biogeography of D. elegans: promoting the dispersal of the second lineage towards higher latitudes and preventing the first lineage from moving northward. Principal component analysis showed that habitat conditions and morphologies differed between the two D. elegans lineages. This study provides insights into the cryptic diversity of Dichotomaria in Taiwan, as well as the genetic divergence, biogeographical patterns, and ecological associations of D. elegans, highlighting the interplay of island formation and currents shaping the diversification of seaweeds in the Northwest Pacific Ocean.

Formation of pure zirconium islands inside c-component loops in high-burnup fuel cladding

High-burnup Zr-based nuclear fuel claddings exhibit accelerated irradiation growth, corrosion and hydrogen pick-up, all correlated with the emergence of c-component dislocation loops. We made use of sub-nm-resolution atom probe tomography to characterize the nanoscale chemistry of c-loops in fuel cladding from boiling water reactor operation. We found segregation of Fe, Ni and Sn to dislocation lines and depletion of Sn and O inside the loops, resulting in nearly pure Zr islands. We also observed nucleation of suboxide inside one c-loop, pointing to a possible mechanism of accelerated in-reactor corrosion. The Zr islands might also promote hydride precipitation and associated degradation.

Preparation of highly dispersed Pt catalyst by CeOx 'islands' modification of dendritic mesoporous SiO2: CO as a probe molecule

There are still challenges in producing noble metal catalysts with atomic dispersion on a large scale in current. This study presents a method for preparing a highly dispersed Pt catalyst (Pt/CeOx/DMS) by modifying dendritic mesoporous SiO2 (DMS) with CeOx 'islands'. The results demonstrate that Pt is highly dispersed on the CeOx/DMS carrier, with the majority of Pt existing in the form of single atoms (Pt/20 wt.% CeOx/DMS). The dendritic DMS has a large specific area (451 m2 g−1) that provides more sites for the formation of CeOx 'islands'. This promotes the dispersion of Pt, significantly improving the oxidation activity of CO. The addition of CeOx 'islands' to the Pt/DMS catalyst promotes the desorption of CO on Pt NPs, enhances the adsorption and activation of O2, and further improves the activity of catalyst. This is because of the synergistic effect between Pt and CeOx 'islands'. The DFT result found that it is more beneficial for Pt1 to adsorb O2 before other reactions. To test the activity and stability of the catalyst, the team conducted catalytic oxidation of CO as a model reaction. The results show that the promotion of CeOx 'island' reduces T90 of CO catalytic oxidation by 16 ℃. In the high-temperature stability test of the catalyst, it was observed that even after reacting at 500 ℃ for 8 h, the catalyst can still achieve 90 % conversion of CO at 147 ℃, demonstrating its good stability. This study provides a foundation for designing a new type of CO oxidation catalyst. The catalyst features high dispersion Pt and exhibits excellent catalytic activity.

Phase Change Heterostructure Memory with Oxygen-DopedSb2Te3 Layersfor Improved Durability and Reliability through Nano crystalline Island Formation.

Phase-change random access memory represents a notable advancement in nonvolatile memory technology; however, it faces challenges in terms of thermal stability and reliability, hindering its broader application. To mitigate these issues, doping and structural modification techniques such as phase-change heterostructures (PCH) are widely studied. Although doping typically enhances thermal stability, it can adversely affect the switching speed. Structural modifications such as PCH have struggled to sustain stable performance under high atmospheric conditions. In this study, these challenges are addressed by synergizing oxygen-doped Sb2Te3 (OST) with PCH technology. This study presents a novel approach in which OST significantly improves the crystallization temperature, power efficiency, and cyclability. Subsequently, the integration of the PCH technology bolsters the switching speed and further amplifies the device's reliability and endurance by refining the grain size (≈7nm). The resultant OST-PCH devices exhibit exceptional performance metrics, including a drift coefficient of 0.003 in the RESET state, endurance of ≈4 × 108 cycles, an switching speed of 300ns, and 67.6 pJ of RESET energy. These findings suggest that the OST-PCH devices show promise for integration into embedded systems, such as those found in automotive applications and Internet of Things devices.

Hotspots of biogeochemical activity linked to aridity and plant traits across global drylands.

Perennial plants create productive and biodiverse hotspots, known as fertile islands, beneath their canopies. These hotspots largely determine the structure and functioning of drylands worldwide. Despite their ubiquity, the factors controlling fertile islands under conditions of contrasting grazing by livestock, the most prevalent land use in drylands, remain virtually unknown. Here we evaluated the relative importance of grazing pressure and herbivore type, climate and plant functional traits on 24 soil physical and chemical attributes that represent proxies of key ecosystem services related to decomposition, soil fertility, and soil and water conservation. To do this, we conducted a standardized global survey of 288 plots at 88 sites in 25 countries worldwide. We show that aridity and plant traits are the major factors associated with the magnitude of plant effects on fertile islands in grazed drylands worldwide. Grazing pressure had little influence on the capacity of plants to support fertile islands. Taller and wider shrubs and grasses supported stronger island effects. Stable and functional soils tended to be linked to species-rich sites with taller plants. Together, our findings dispel the notion that grazing pressure or herbivore type are linked to the formation or intensification of fertile islands in drylands. Rather, our study suggests that changes in aridity, and processes that alter island identity and therefore plant traits, will have marked effects on how perennial plants support and maintain the functioning of drylands in a more arid and grazed world.

Photoelectrochemical Proton-Coupled Electron Transfer of TiO2 Thin Films on Silicon.

TiO2 thin films are often used as protective layers on semiconductors for applications in photovoltaics, molecule-semiconductor hybrid photoelectrodes, and more. Experiments reported here show that TiO2 thin films on silicon are electrochemically and photoelectrochemically reduced in buffered acetonitrile at potentials relevant to photoelectrocatalysis of CO2 reduction, N2 reduction, and H2 evolution. On both n-type Si and irradiated p-type Si, TiO2 reduction is proton-coupled with a 1e-:1H+ stoichiometry, as demonstrated by the Nernstian dependence of the Ti4+/3+ E1/2 on the buffer pKa. Experiments were conducted with and without illumination, and a photovoltage of ∼0.6 V was observed across 20 orders of magnitude in proton activity. The 4 nm films are almost stoichiometrically reduced under mild conditions. The reduced films catalytically transfer protons and electrons to hydrogen atom acceptors, based on cyclic voltammogram, bulk electrolysis, and other mechanistic evidence. TiO2/Si thus has the potential to photoelectrochemically generate high-energy H atom carriers. Characterization of the TiO2 films after reduction reveals restructuring with the formation of islands, rendering TiO2 films as a potentially poor choice as protecting films or catalyst supports under reducing and protic conditions. Overall, this work demonstrates that atomic layer deposition TiO2 films on silicon photoelectrodes undergo both chemical and morphological changes upon application of potentials only modestly negative of RHE in these media. While the results should serve as a cautionary tale for researchers aiming to immobilize molecular monolayers on "protective" metal oxides, the robust proton-coupled electron transfer reactivity of the films introduces opportunities for the photoelectrochemical generation of reactive charge-carrying mediators.

Optimizing Ag films towards efficient flexible quantum-dot light-emitting diodes

Metal film electrodes are frequently adopted in flexible quantum-dot light-emitting diodes (FQLEDs) to form microcavity structures, which accelerate the recombination of excitons and thereby enhancing the efficiency of devices, especially under high driving current density. However, metal films prepared by thermal evaporation grow according to the Volmer-Weber nucleation mechanism, thereby resulting in the formation of numerous metal islands on the target substrate. The serious leakage current and light scattering (hence weakened microcavity effect) caused by these islands lead to inefficient FQLEDs. Here we fabricated a highly uniform and smooth Ag-based flexible electrode by utilizing an ultrathin polyethyleneimine as the nucleation-inducing seed layer. A smooth surface with a root-mean-square of approximately 3.7 nm and an ultralow sheet resistance of 3.65 Ω sq−1 have been obtained for the Ag film with a thickness of only 16 nm. Thus, a high-efficiency FQLED is achieved with the maximum external quantum efficiency up to 25.6 %. Furthermore, this device exhibits ultralow efficiency roll-off, characterized by the external quantum efficiency of over 20 % across an extremely wide luminance range, from 300 to 160,000 cd m−2, meeting all display and lighting requirements.

Disproportionate exposure to urban heat island intensity – The case study of Győr, Hungary

Extensive research has shown that urbanisation has a profound effect on the local climate system, leading to the formation of urban heat island. Exposure to urban heat islands poses a major health risk, and there is a growing body of literature recognising that urban population groups with particular demographic characteristics living in specific types of residential environments are disproportionately affected. By combining surface urban heat island data from the Global Surface Urban Heat Island Explorer with neighbourhood-level data on demographics and the type of housing, this study assesses disproportionate exposure to surface urban heat island intensity in the city of Győr, Hungary. Results of the study highlight the importance of targeted interventions for environmental justice, especially in areas characterised by housing estates, high population density and high ageing index.

Comparing silver and gold nanoislands’ surface plasmon resonance for bisacodyl and its metabolite quantification in human plasma

Gold and silver nanoparticles have witnessed increased scientific interest due to their colourful colloidal solutions and exceptional applications. Comparing the localized surface plasmon resonance (LSPR) of gold and silver nanoparticles is crucial for understanding and optimizing their optical properties. This comparison informs the design of highly sensitive plasmonic sensors, aids in selecting the most suitable nanoparticles for applications like surface-enhanced infrared spectroscopy (SEIRA) and biomedical imaging, and guides the choice between gold and silver nanoparticles based on their catalytic and photothermal properties. Ultimately, the study of LSPR facilitates the tailored use of these nanoparticles in diverse scientific and technological applications. Two SEIRA methods combined with partial least squares regression (PLSR) chemometric tools were developed. This development is based on the synthesis of homogeneous, high-dense deposited metal nanoparticle islands over the surface of glass substrates to be used as lab-on-chip SEIRA sensors for the determination of bisacodyl (BIS) and its active metabolite in plasma. SEM micrographs revealed the formation of metallic islands of colloidal citrate-capped gold and silver nanoparticles of average sizes of 29.7 and 15 nm, respectively. BIS and its active metabolite were placed on the nanoparticles’ coated substrates to be directly measured, then PLSR chemometric modelling was used for the quantitative determinations. Plasmonic citrate-capped gold nanoparticle substrates showed better performance than those prepared using citrate-capped silver nanoparticles in terms of preparation time, enhancement factor, PLSR model prediction, and quantitative results. This study offers a way to determine BIS and its active metabolite in the concentration range 15–240 ng/mL in human plasma using inexpensive disposable glass-coated substrates that can be prepared in 1 h to get results in seconds with good recovery between 98.77 and 100.64%. The sensors provided fast, simple, selective, molecular-specific and inexpensive procedures to determine molecules in their pure form and biological fluid.

Mapping impervious surface change from remote sensing and GIS data: A case study in Hochiminh city, Vietnam

Impervious surface is artificial surfaces that prevent water from entering the soil. The increase in impervious surface area has led to negative impacts on the urban environment, including an increase in the risk of flooding, a decrease in vegetation cover, and the formation of urban heat islands. This paper presents the results of building a predictive model of impervious surfaces in Hochiminh city from remote sensing and GIS data. Landsat and Sentinel 2 satellite images for the period 2002–2022 are used to classify impervious surfaces and extract input layers about vegetation cover, land surface temperature, combined with GIS data (elevation, slope, aspect, distance to road, distance to hydrology, population density) for modeling and predicting impervious surface changes in future. 03 machine learning algorithms, including Support Vector Machine (SVM), Random Forest (RF), Classification and Regression Trees (CART) and maximum likelihood method are used to classify impervious surfaces from Landsat satellite images, then select the method with the highest accuracy. To predict the future distribution of impervious surface, this study uses Cellular Automata (CA) model and 02 artificial intelligence algorithms (Artificial Neural Network - ANN, Logistic Regression - LR). The results obtained in the study can be effectively used for urban planning, minimizing the impact of the process of increasing the impervious surface on the urban environment

‘Fertile island’ effects on the soil microbial community beneath the canopy of Tetraena mongolica, an endangered and dominant shrub in the West Ordos Desert, North China

BackgroundThe fertile islands formed by shrubs are major drivers of the structure and function of desert ecosystems, affecting seedling establishment, plant–plant interactions, the diversity and productivity of plant communities, and microbial activity/diversity. Although an increasing number of studies have shown the critical importance of soil microbes in fertile island formation, how soil microbial community structure and function are affected by the different fertile island effect intensities is still unknown. As an endangered and dominant shrub species in the West Ordos Desert, Tetraena mongolica was selected for further exploration of its fertile island effect on the soil microbial community in the present study to test the following two hypotheses: (1) T. mongolica shrubs with different canopy sizes exert fertile island effects of different strengths; (2) the soil microbial community structure and function beneath the T. mongolica canopy are affected by the fertile island, and the strength of these effects varies depending on the shrub canopy size.ResultsThe contents of soil total nitrogen (TN) and available phosphorus (AVP) were significantly greater beneath T. mongolica shrub canopy than outside the shrub canopy. With increasing shrub canopy size, the enrichment of soil TN and AVP increased, indicating a stronger fertile island effect. The structure and function of soil microbial communities, including fungal, archaeal and bacterial communities, are affected by the fertile island effect. An increase in canopy size increased the relative abundance of Ascomycota (Fungi) and Thaumarchaeota (Archaea). For the soil microbial functional groups, the relative abundance of endophytes in the fungal functional groups; steroid hormone biosynthesis, sphingolipid metabolism, and steroid biosynthesis genes in the bacterial functional groups; and nonhomologous end-joining and bisphenol degradation functional genes in the archaeal functional groups increased significantly with increasing T. mongolica canopy size.ConclusionsThese results revealed that T. mongolica had a fertile island effect, which affected the soil microbial community structure and functions, and that the fertile island effect might increase with increasing shrub canopy size. The fertile island effect may strengthen the interaction between T. mongolica shrubs and microbes, which may be beneficial to the growth and maintenance of T. mongolica.

FORMATION OF BRANCHES AT RIVER MEANDERS

When studying channel morphodynamics, the processes and forms of meandering and branching are considered independently. However, the development of meanders on large rivers is complicated by the formation of islands on their limbs and in the neartop parts. The most striking manifestation of the process is the branched-winding channels, which develop as a result of the successive formation of islands, creating spurs of meanders if attached to the coastal floodplain. The relief of the floodplains of such rivers is hollow-island in contrast to the ridged relief of typical meandering rivers. Another form of such channels of large rivers is alternating unilateral ramifications, in which the meanders of the main (highwater) branch go around the groups of islands located in a checkerboard pattern, and the channel itself in the floodplain banks remains quasirectilinear while in a branched-winding channel it forms segmental meanders. The presence of branches at a meander of the channel disperses the runoff, and decreases the amount of water in the main branch, thus affecting the parameters of the meanders.Islands are also formed in the neartop parts of meanders, where its dynamic axis shifts towards the convex coast due to the violation of continuous flow around the banks, and erodes it. In the resulting local widening of the channel, a middle center appears and, when it is overgrown, an island is formed. A local widening of the channel is formed on rectilinear «inserts» between adjacent large meanders when the floodplain and channel flows intersect during the flood, and a middle or island is also formed in it. On the upper wings of steep bends, especially forced meanders, the formation of branches is associated with the flow backwater that occurs when it approaches the bedrock bank at the top of the meander at a high angle.The formation of branchings at the meanders of a channel should be taken into account during river development as a factor that can influence the conditions of navigation and influence the channel reshaping, which is particularly important at the places where linear structures, such as bridges and pipelines, cross the rivers.

Novel mechanisms of diversity generation in Acinetobacter baumannii resistance islands driven by Tn7-like elements.

Mobile genetic elements play an important role in the acquisition of antibiotic and biocide resistance, especially through the formation of resistance islands in bacterial chromosomes. We analyzed the contribution of Tn7-like transposons to island formation and diversification in the nosocomial pathogen Acinetobacter baumannii and identified four separate families that recognize different integration sites. One integration site is within the comM gene and coincides with the previously described Tn6022 elements suggested to account for the AbaR resistance island. We established Tn6022 in a heterologous E. coli host and confirmed basic features of transposition into the comM attachment site and the use of a novel transposition protein. By analyzing population features within Tn6022 elements we identified two potential novel transposon-encoded diversification mechanisms with this dynamic genetic island. The activities of these diversification features were confirmed in E. coli. One was a novel natural gain-of-activity allele that could function to broaden transposition targeting. The second was a transposon-encoded hybrid dif-like site that parasitizes the host dimer chromosome resolution system to function with its own tyrosine recombinase. This work establishes a highly active Tn7-like transposon that harnesses novel features allowing the spread and diversification of genetic islands in pathogenic bacteria.

Impacts of urbanization on land use, air quality, and temperature dynamics in Dehradun district of Uttarakhand, India: a comprehensive analysis

The present study investigates the impact of urbanization on land surface temperature and air quality in Dehradun district of the Uttarakhand state in India. We utilized data from LANDSAT, TROPOMI, OMI, MODIS, MOPITT, and CHIRPS, for spatio-temporal and trend analyses along with the assessment of correlation matrix. Our findings revealed a significant increase in the built-up area of Dehradun district in 2023 as compared to 2003. This expansion was particularly prominent in the southern and south-eastern regions of the district. The findings highlight the impact of rapid urban expansion on land use and land cover, leading to a rise in land surface temperature (LST) and the formation of surface urban heat islands (SUHI). Notably, the study reveals distinct spatial and temporal patterns, with lower regions of Dehradun district experiencing higher temperatures and pollutant concentrations due to intensified urbanization. Dehradun city also emerged as a hotspot for nitrogen dioxide within the district. Long-term trends indicate a rise in formaldehyde and nitrogen dioxide, attributed to both urbanization and increasing temperatures, while carbon monoxide levels decrease due to reduced biomass burning and the adoption of cleaner household fuels. Correlation matrix analysis underscores the complex relationships between land use, temperature, and pollutants, with built-up areas exhibiting strong positive correlations with all pollutants. This comprehensive study highlights the importance of sustainable urban planning and management to mitigate the adverse effects of rapid urbanization on air quality and overall environmental health in the Dehradun district.

Geospatial Insights into Aridity Conditions: MODIS Products and GIS Modeling in Northeast Brazil

Northeast Brazil (NEB), particularly its semiarid region, represents an area highly susceptible to the impacts of climate change, including severe droughts, and intense anthropogenic activities. These stresses may be accelerating environmental degradation and desertification of soil in NEB. The main aim of this study was to gain geospatial insights into the biophysical parameters of surface energy balance and actual evapotranspiration on a multi-temporal scale, aiming to detect and analyze the spectral behavioral patterns of areas vulnerable to degradation processes, based on thematic maps at the surface, for NEB and mainly the semiarid region of NEB from 2000 to 2019. Geospatial data from 8-day MODIS sensor products were used, such as surface reflectance (Terra/MOD09A1 and Aqua/MYD09A1), surface temperature (Terra/MOD11A2 and Aqua/MYD11A2), and actual evapotranspiration (Terra/MOD16A2 and Aqua/MYD16A2), version 6. Therefore, in this study, pixel-to-pixel values were processed by calculating the average pixel statistics for each year. From the reflectance product, digital processing of the surface albedo and spectral vegetation indices was also carried out, using computational programming scripts and machine learning algorithms developed via the Google Earth Engine (GEE) platform. The study also presents a seasonal analysis of these components and their relationships over 20 years. Through vegetation indices and statistical correlations, a new predictive model of actual evapotranspiration was developed. The quantitative and spatiotemporal spectral patterns of the parameters were assessed through descriptive statistics, measures of central tendency and dispersion, and statistical error analyses and correlation indices. Thematic maps highlighted the pixel-to-pixel results, with patterns of high temperature distribution mainly in the central and northeastern part of NEB and the semiarid region of NEB, highlighting the formation of persistent heat islands over time. Meanwhile, in these areas, the maps of actual evapotranspiration showed a drastic reduction due to the lesser availability of energy. Over time, the semiarid region of NEB presented areas with little and/or no vegetation cover, which were highly well-defined between the years 2012 and 2019, confirming that these areas are extremely vulnerable to degradation and desertification processes due to significant loss of vegetative and water resilience. The components of energy balance were highly interconnected to climatological and environmental conditions, showing the severe results of drought and accentuation of the water deficit in NEB, presenting a greater condition of aridity in the semiarid region of NEB over time.

Intermittent Electron-only Reconnection at Lunar Mini-magnetospheres

Lunar crustal magnetic anomalies (LCMA) are sub-ion-gyroradius structures that have been shown to stand off the solar wind (SW) plasma from the Moon’s surface, forming shock-like discontinuities and reflecting incident SW protons. In this Letter, the results of high-resolution, 2D fully kinetic simulations show a bursty electron-only magnetic reconnection in the SW-LCMA interaction region, characterized by the quasiperiodic formation and ejection of magnetic islands and strong parallel electron flows along the X-point separator lines. The islands are observed to modify the magnetic pressure pileup and Hall electric field above the LCMA, leading to sharp increases in reflected protons that drive electromagnetic fluctuations downstream and short distances upstream in the SW.

The effectiveness of geothermal systems in cooling residential buildings: a case study of a residential building in Alexandria, Egypt

AbstractThe urbanization of cities, the corroding of green areas, and the increasing demand for electric energy lead to the formation of heat islands in cities and the appearance of the global climate change phenomenon.Therefore, it was necessary to resort to the use of renewable energy sources, such as geothermal energy, to be used in different applications, as it can be used to cool buildings in cities during the summer.This research deals with the benefits of using geothermal energy systems, their different types, and the possibility of their application in Egypt. Also discussing the effectiveness of the vertical closed geothermal system in residential buildings in Alexandria Governorate in Egypt to reach an answer to a question.The effectiveness of the geothermal energy system in residential buildings is to reduce the problem of rising temperatures, energy consumption for cooling, and carbon emissions and thus reduce the problem of the formation of heat islands in cities and the appearance of the global climate change phenomenon and reaching a sustainable, environmentally friendly building that achieves thermal comfort for humans through the use of a simulation program called TRNSYS-17, through which the current situation of the building was compared and the addition of a vertical closed geothermal system was assumed, the extent of its effectiveness was compared in the whole building, and the cost of a vertical closed geothermal system and a traditional air conditioning system (HVAC) in a building was compared (case study).Hence, the efficiency of the vertical closed geothermal system appeared to reduce electric energy consumption and carbon emissions in the whole building at Alexandria in Egypt, especially the ground floor, which reached thermal comfort for humans and worked to reduce electricity consumption and carbon emissions by up to 22.93% in the building as a whole.