Mass Variation Research Articles

Monitoring the response of Saudi Arabia's largest fossil aquifer system to climate variability

The study utilizes an integrated approach that involves GRACE and Global Precipitation Climatology Project (GPCP) data to analyze temporal water mass variations in Saudi Arabia (KSA). Recently, KSA has witnessed a historic wet period between 2018 and 2020 (i.e., 120–150 mm/year) following a prolonged dry period between 2002 and 2017 (i.e., 80–100 mm/year). Inspection of GRACE data showed a decline in groundwater recharge of −4 to −6 mm during the dry period. The depletion was reduced by 1 to 6.8 mm in the Northeastern side of KSA (e.g. Hail, Al-Jouf, Al-Hudud Ash-Shamaliyah areas) during the wet period. This impressive recovery has led to a groundwater recharge increase of 360 km3 in Hail, 174 km3 in Al-Jouf and 97 km3 in Al-Hudud Ash-Shamaliyah. The findings emphasize the notion that climate change will bring more frequent extreme climatic events to the Kingdom of Saudi Arabia and call for continuous monitoring of aquifers every year.

From clusters of moving molecules to continua: Material elements as open systems

We discuss the discrete-to-continuum transition in the description of matter, starting from a cluster of flowing molecules with equal mass and ending up with a non-simple fluid. We account for the fluctuations beyond a local affine approximation of the velocity distribution of molecules within a space window adopted to compute some prominent statistics. The resulting continuum picture accounts for local mass variation in each space window corresponding to a point in the continuum scale. From a statistical viewpoint, every material element is thus considered as a grand-canonical ensemble. So-called C-derivatives account for macroscopic-to-mesoscopic relative motion. When considered for second-rank tensors, they extend Truesdell’s derivative and reduce to Oldroyd’s one when the macroscopic-to-mesoscopic relative motion vanishes. Fluctuations beyond an affine component best approximating the kinetic energy are summarized into a second-rank symmetric tensor whose time variation enters a balance equation governing transfer from velocity fluctuations to heat. Eventually, we discuss essential elements of thermodynamics in the present setting. What emerges is the possibility of a non-Fourier type heat transfer. The results address computational schemes for field representations of sparse phase dynamics, such as granular materials, and the one of bodies with transport of scattered molecules, such as pollutants in fluids or proteins in biological tissues.

Effect of intraspecific seed trait variation on the germination of eight tropical dry forest species

Functional traits can have intraspecific and interspecific variations essential in the structure and dynamics of natural communities. These traits may have implications in the germination and seedling establishment phases in seeds. The objective of this study was to evaluate the effect of variations in mass, volume, and nutrient content (C, N, and P) on the germination of eight species representative of the tropical dry forest (TDF). Our results showed that seed size, both in terms of mass and volume, did not predict germination rates or percentages, nor were they related to nutrient content. In contrast, N content was the most important trait in the germination phase. Larger seeds did not germinate more or faster, but they could offer better resistance against desiccation, since they had higher C/N ratios in their tissues, a characteristic of orthodox seeds. The species A. guachapele, B. arborea, H. crepitans, and V. tortuosa presented a high biological potential in terms of their regeneration capacity, particularly, because the characteristics of their seeds, as well as the nutrient content, revealed consistent implications in their reproductive success, promoting high germination percentages in less time. In general, the results obtained in this study provide basic knowledge for future research, offering starting points for further exploration of species-specific adaptations and how they may be affected by the environment.

Transient magnetohydrodynamic heat and mass transfer analysis of chemically reacting fluid flow over oscillatory permeable media

This study focuses on the numerical observation of the convective motion of chemically active magnetohydrodynamic (MHD) fluid through a vertically oriented permeable medium, incorporating variations in mass and heat transfer. The fluid type is assumed to be incompressible, chemically strongly ionized and viscous with some mass infusibility. The model associated with this problem is solved by a highly stable Implicit Finite Difference Method (IFDM). The method is used for small and large deflection of the physical parameters, which results in a noticeable fluid flow behavior. Numerical configuration is graphically depicted to scrutinize the fluid behavior. The momentum, energy, concentration diffusion, skin friction, Nusselt number and Sherwood number are investigated for numerous factors such as magnetic field, permeability and chemical reaction rate. The current study unveils significant findings, demonstrating that a heightened rate of chemical reaction in the presence of magnetic effects, coupled with specific porosity, diminishes ionization energy, resulting in a concurrent decrease in the concentration and momentum profiles of the fluid flow. The rise in the viscous diffusion rate is attributed to escalating values of the Schmidt number, causing an augmentation in dynamic viscosity and consequently resulting in an overall reduction in the momentum of the fluid flow.

Water masses influence the variation of microbial communities in the Yangtze River Estuary and its adjacent waters.

The Yangtze River estuary (YRE) are strongly influenced by the Kuroshio and terrigenous input from rivers, leading to the formation of distinct water masses, however, there remains a limited understanding of the full extent of this influence. Here the variation of water masses and bacterial communities of 58 seawater samples from the YRE and its adjacent waters were investigated. Our findings suggested that there were 5 water masses in the studied area: Black stream (BS), coastal water in the East China Sea (CW), nearshore mixed water (NM), mixed water in the middle and deep layers of the East China Sea (MM), and deep water blocks in the middle of the East China Sea (DM). The CW mass harbors the highest alpha diversity across all layers, whereas the NM mass exhibits higher diversity in the surface layer but lower in the middle layers. Proteobacteria was the most abundant taxa in all water masses, apart from that, in the surface layer masses, Cyanobacterium, Bacteroidota, and Actinobacteriota were the highest proportion in CW, while Bacteroidota and Actinobacteriota were the highest proportion in NM and BS; in the middle layer, Bacteroidota and Actinobacteriota were dominant phylum in CW and BS masses, but Cyanobacterium was main phylum in NM mass; in the bottom layer, Bacteroidota and Actinobacteriota were the dominant phylum in CW, while Marininimicrobia was the dominated phylum in DM and MM masses. Network analysis suggests water masses have obvious influence on community topological characteristics, moreover, community assembly across masses also differ greatly. Taken together, these results emphasized the significant impact of water masses on the bacterial composition, topological characteristics and assembly process, which may provide a theoretical foundation for predicting alterations in microbial communities within estuarine ecosystems under the influence of water masses.

Pimobendan controlled release guar gum printlets: Tailoring drug doses for personalised veterinary medicines

Treating chronic heart diseases in dogs is challenging due to variations in mass within and between species. Pimobendan (PBD), a veterinary drug only, is prescribed in specific cases of chronic heart disease in dogs and is available on the market in only a few different doses. Furthermore, the therapy itself is challenging due to the large size of the chewable tablets and the requirement for twice-daily administration. The development of customised and on-demand PBD medicines by three-dimensional (3D) printing has been proposed to circumvent these disadvantages. In this study, we designed controlled-release flavoured printlets containing PBD. We evaluated the use of two natural polymers, guar or xanthan gums, as the main component of the printing inks. Guar gum showed the better rheological behavior and printability by semisolid extrusion. The printlets were produced in three different shapes and sizes to allow dose customisation. Guar gum printlets showed a PBD controlled release profile, regardless of their shape or size. Therefore, we have demonstrated a novel approach for controlling PBD drug release and tailoring the dose by employing a natural polymer to produce 3D-printed tablets. This study represents a significant step towards the development of 3D-printed guar gum controlled-release formulations for veterinary applications.

Data-driven approach for the detection of faults in district heating networks

At present, District Heating Networks (DHNs) are required to operate more and more reliably and efficiently in order to further save primary energy and reduce environmental impact. Thus, monitoring and diagnostic approaches are necessary to identify the typical faults that affect this type of systems (e.g., anomalous heat and pressure losses), with the final goal of optimizing DHN operation and management. To this aim, this paper presents a data-driven diagnostic methodology that exploits NARX (nonlinear autoregressive network with exogenous inputs) neural networks to simulate DHN healthy operation and a threshold-based criterion for fault detection and identification. The novel diagnostic methodology is tested for evaluating the health state of the DHN of the campus of the University of Parma (Italy), based on the availability of time series of measurable variables (mass flow rate, pressure, and temperature) for both the power plant and the end-users. Both single and multiple faults of anomalous heat losses and anomalous pressure losses, with different magnitudes and location, were artificially implanted in DHN pipes. The main novel contribution of this paper with respect to state-of-the-art literature relies on the development of a real-time simulation approach aimed to predict DHN future operation and detect abnormal deviations from normal operation. The methodology proves to correctly detect and identify all simulated faults related to heat and pressure losses, by also correctly estimating their magnitude even in the most challenging scenarios.

Identifying Damage in Structures: Definition of Thresholds to Minimize False Alarms in SHM Systems

In recent years, the development of quick and streamlined methods for the detection and localization of structural damage has been achieved by analysing key dynamic parameters before and after significant events or as a result of aging. Many Structural Health Monitoring (SHM) systems rely on the relationship between occurred damage and variations in eigenfrequencies. While it is acknowledged that damage can affect eigenfrequencies, the reverse is not necessarily true, particularly for minor frequency variations. Thus, reducing false positives is essential for the effectiveness of SHM systems. The aim of this paper is to identify scenarios where observed changes in eigenfrequencies are not caused by structural damage, but rather by non-stationary combinations of input and system response (e.g., wind effects, traffic vibrations), or by stochastic variations in mass, damping, and stiffness (e.g., environmental variations). To achieve this, statistical variations of thresholds were established to separate linear non-stationary behaviour from nonlinear structural behaviour. The Duffing oscillator was employed in this study to perform various nonlinear analyses via Monte Carlo simulations.

Experimental investigations on MICP-based autonomous crack-healing recycled aggregate concrete: a sustainable approach for enhancing the strength and durability

ABSTRACT Cracks in concrete, including recycled aggregate concrete (RAC), lead to durability issues from substance penetration. This study introduces microbial precipitation for crack healing in RAC. It substitutes 50% and 100% of natural coarse aggregate with recycled coarse aggregate and replaces cement with blends of hydrated lime and brick powder. Self-healing effectiveness is assessed through compressive strength, RCPT, UPV, and microscopic analysis. Results show complete healing of 0.58 mm cracks over 56 days, with compressive strength regain ranging from 94% to 56%. RCPT variation ratios range from 142% to 173%. Microstructural analysis through FESEM, EDS, and XRD reveals microbial precipitate properties. FTIR and TGA analyses explore CaCO3 through infrared absorbance and mass variation with temperature. The study suggests that microbial-induced self-healing improves strength and durability in recycled aggregate concrete.

Optimum design of additively manufactured aerospace components with different lattice structures

Abstract Nowadays, the need for new technologies is increasing, especially to find solutions to the inadequacies in the production of complex structures. The additive manufacturing methods developed facilitate the production of complex parts and move the technology forward with factors such as cost and efficiency. With the optimization of new parts designed by additive manufacturing methods, it is possible to obtain the optimum product even in the most complex structures. At the end of the production process, the final product with the desired properties is obtained as a result of part size tolerance precision and optimizations. In this study, lattice optimization is applied to a passenger aircraft bracket. It is aimed to reduce the weight and, at the same time, increase the efficiency of the part by optimizing it with lattice structures. For this purpose, the Altair Inspire program was used, and the variation of mass, displacement, safety coefficient, and stress values of the part according to different lattice structures were investigated.

GPS displacement dataset for the study of elastic surface mass variations

Abstract. Quantification of uncertainty in surface mass change signals derived from Global Positioning System (GPS) measurements poses challenges, especially when dealing with large datasets with continental or global coverage. We present a new GPS station displacement dataset that reflects surface mass load signals and their uncertainties. We assess the structure and quantify the uncertainty of vertical land displacement derived from 3045 GPS stations distributed across the continental US. Monthly means of daily positions are available for 15 years. We list the required corrections to isolate surface mass signals in GPS estimates and screen the data using GRACE(-FO) as external validation. Evaluation of GPS time series is a critical step, which identifies (a) corrections that were missed, (b) sites that contain non-elastic signals (e.g., close to aquifers), and (c) sites affected by background modeling errors (e.g., errors in the glacial isostatic model). Finally, we quantify uncertainty of GPS vertical displacement estimates through stochastic modeling and quantification of spatially correlated errors. Our aim is to assign weights to GPS estimates of vertical displacements, which will be used in a joint solution with GRACE(-FO). We prescribe white, colored, and spatially correlated noise. To quantify spatially correlated noise, we build on the common mode imaging approach by adding a geophysical constraint (i.e., surface hydrology) to derive an error estimate for the surface mass signal. We study the uncertainty of the GPS displacement time series and find an average noise level between 2 and 3 mm when white noise, flicker noise, and the root mean square (rms) of residuals about a seasonality and trend fit are used to describe uncertainty. Prescribing random walk noise increases the error level such that half of the stations have noise > 4 mm, which is systematic with the noise level derived through modeling of spatially correlated noise. The new dataset is available at https://doi.org/10.5281/zenodo.8184285 (Peidou et al., 2023) and is suitable for use in a future joint solution with GRACE(-FO)-like observations.

Influence of blend ratio of cotton and Arecanut fibers on yarn properties

PurposeThe purpose of the study is to optimize the blending ratio of Arecanut and cotton fibers to create yarn with the best quality for various applications, particularly home furnishings. The study aims to determine the effect of different blend ratios on the physical and mechanical properties of the yarn.Design/methodology/approachThe study involves blending Arecanut and cotton fibers in various ratios (90:10, 75:25, 50:50, 25:75 and 10:90) at two different yarn counts (10/1 and 5/1). Various physical and mechanical properties of the blended yarn are analyzed, including unevenness, coefficient of mass variation (cvm%), imperfection, hairiness, breaking strength, elongation, tenacity and breaking work.FindingsThe research findings suggest that the blend ratio of 10:90 (10% cotton and 90% Arecanut fiber) produced the best results in terms of physical and mechanical properties for both yarn counts. This blend ratio resulted in reduced unevenness, cvm% and imperfection, while also exhibiting good mechanical properties such as breaking strength, elongation, tenacity and breaking work. The blend with a higher concentration of cotton generally showed better properties due to the coarseness of Arecanut fiber. As the goal of the study was to determine the best blend ratio that included the most Arecanut fiber based on its physical and mechanical properties, which is suitable for home furnishing applications, 75:25 Areca cotton blend ratio of yarn count 5/1 proved to be the best.Research limitations/implicationsThe study acknowledges that Arecanut fiber must be blended with other commercially used fibers like cotton due to its coarseness. While the study provides insights into optimizing blend ratios for home furnishings and packaging, further research may be needed to make the material suitable for clothing applications.Practical implicationsThe research has practical implications for industries interested in utilizing Arecanut and cotton blends for various applications, such as home furnishings and packaging materials. It suggests that specific blend ratios can result in yarn with desirable properties for these purposes.Social implicationsThe study mentions that the increased use of Arecanut fibers can benefit the growers of Arecanut, potentially providing economic opportunities for communities engaged in Arecanut farming.Originality/valueThe research explores the utilization of Arecanut fibers, an underutilized resource, in combination with cotton to create sustainable yarn. It assesses various blend ratios and their impact on yarn properties, contributing to the understanding of eco-friendly textile materials.

Mass variations and transfer process of shrimp farming pollutants in aquaculture drainage systems: Effects of DOM features and physicochemical properties

The expansion of aquaculture produces increasing pollutant loads, necessitating the use of drainage systems to discharge wastewater into surface water. To assess the mass variations and transfer process of aquaculture wastewater, an entire aquaculture drainage investigation lasting for 48 h was conducted, focusing on the nutrients, heavy metals, dissolved organic matter (DOM), and physicochemical properties of drainage in a commercial shrimp farm. The findings revealed that early drainage produced more heavy metals, total nitrogen (TN), dissolved organic nitrogen (DON), and feed-like proteins from aquaculture floating feed and additives, whereas late drainage produced more PO43--P and total dissolved phosphorus (TP). A few pollutants, including DON, Cu, and feed-like proteins, were effectively removed, whereas the contents of TN, dissolved inorganic nitrogen, and Zn increased in the multi-level aquaculture drainage system. Limited dilution indicated that in-stream transfer was the main process shaping pollutant concentrations within the drainage system. In the lower ditches, NO3--N, heavy metals, and feed-like proteins exhibited evident in-stream attenuation, while TN and NH4+-N underwent significant in-stream enrichment processes, especially in ditch C, with the transfer coefficient values (vf) of –1.74E-5 and –2.04E-5. This indicates that traditional aquaculture drainage systems serve as nitrogen sinks, rather than efficient nutrient purge facilitators. Notably, DOM was identified as a more influential factor in shaping the in-stream transfer process in aquaculture drainage systems, with an interpretation rate 40.79% higher than that of the physiochemical properties. Consequently, it is necessary to eliminate the obstacles posed by DOM to pollutant absorption and net zero emissions in aquaculture drainage systems in the future. Environmental implicationsNutrients, heavy metals, and dissolved organic matter are hazardous pollutants originating from high-density aquaculture. As the sole conduit to natural waters, aquaculture drainage systems have pivotal functions in receiving and purifying wastewater, in which the in-stream transfer process is affected by ambient conditions. This field study investigated the spatial variations, stage distinctions, effects of physicochemical properties, and dissolved organic matter (DOM) features. This finding suggests that the aquaculture drainage system as a nitrogen sink and DOM source. While the DOM is the key factor in shaping the in-stream transfer process, and obstacles for pollutant elimination. This study helps in understanding the fate of aquaculture pollutants and reveals the drawbacks of traditional aquaculture drainage systems.

Study of the stochastic dynamics of particles in the coal screening based on the Markov process

The model of the stochastic dynamics for the screening and screen-penetration processes was developed based on the Markov process to reveal the mechanism of the coal screening effect. As a partial differential equation, the model of the stochastic dynamics describes the relationship between particle position in the y direction, screening time, and particle screen-penetration probability. The obtained model for stochastic dynamics can calculate the screen-penetration probability of a specific particle size at any given time. Moreover, two coefficients, a1 and a2, are defined where a1 represents the average velocity of particles, and a2 represents the combined effect of orderly segregation and mixing of particles in chaotic motion. These coefficients of the stochastic dynamics model were obtained by regression analysis. Additionally, the statistical analysis showed that the fitting errors were all <1. The proposed statistical dynamics model works for all particle sizes. A necessary coefficient, a1, was calculated based on screen-penetration coefficients k, a, and b. A large value of a1 means a high average velocity of particles and a greater screen-penetration probability. The value of a1 for particles smaller than 6 mm declines as the feed mass increases. Moreover, it initially decreases, followed by an increase, in response to a rising proportion of particles <6 mm. In contrast, the a1 value for particles ranging between 6 mm and 13 mm undergoes minimal changes when subjected to variations in feed mass and the proportion of particles <6 mm.

Interaction-performance-driven design of negative-stiffness friction pendulum systems for aboveground structure–connected underground structure–soil system with ground motion effects

Within the transit-oriented development framework, aboveground structure–connected underground structures (ASUS) have been widely constructed in urban areas; however, abrupt stiffness changes and complex soil–structure interactions could cause structural damage or business disruption after earthquakes. In this study, to address these challenges, a novel approach is proposed that employs negative stiffness, damping elements, and friction pendulum bearings to enhance the overall performance of ASUS. An interaction-performance-driven design procedure and parameter selection methodology are developed to simultaneously upgrade multiple performance aspects of ASUS. A mechanical model of the negative stiffness amplification system-enabled friction pendulum system (NSAS-FPS) is constructed. The theoretical basis of the equivalent negative stiffness and enhanced energy dissipation effects is elucidated, and a finite element model of the NSAS-FPS-incorporated soil–ASUS interaction system is established. Extensive parametric, robustness, and correlation analyses against short/long-period ground motions are conducted to provide a comprehensive performance assessment framework. Then, an interaction-performance-driven design principle aimed at multiperformance upgrading of aboveground and underground structures is developed with proposed parameter selections and applied in a case study. These results indicate a significant improvement in vibration control for both aboveground and underground structures when utilizing NSAS-FPS compared to utilizing conventional FPSs with the same design. By following the proposed design procedure and parameters, the NSAS-FPS demonstrates enhanced efficiency in isolating energy dissipation and robustness in seismic isolation, as well as resistance against overturning, irrespective of variations in structural masses and functionalities. While the advantages of the NSAS-FPS include its ability to mitigate the effects of stochastic earthquakes, the extent of the performance improvement may decrease during long-period earthquakes. Therefore, the velocity characteristics of seismic excitations need to be carefully incorporated into the NSAS-FPS design, particularly when targeting specific demands for the isolation-layer performance within ASUS.

Study on Varied Bagasse Fiber and Epoxy Resin Compositions with Rice Bran Filler to Biocomposite Characteristics

&lt;p&gt;Natural fibers, with environmental, economic, and cost advantages, are highly sought-after for biocomposite materials. In the present study, the biocomposite samples of epoxy resin (as a matrix), bagasse fiber (as reinforcement), and rice bran (as a filler) were prepared. Tensile strength, strain, and Young's modulus will be the parameters concerning which the quality of the biocomposite can be tested. On the one hand, bagasse fiber is to be a strength enhancer in the resulting biocomposite. On the other hand, rice bran may increase the biocomposite's density. The process research comprises fiber yarn from milled bagasse, alkalized fiber with KMnO4, specimen printing process, and analysis. All the fibers were treated by soaking them in 3 grams of KMnO4 solution for 30 and 45 minutes. The fiber is drained in an oven at 50 °C for ±1.5 hours. The printed fiber onto a specimen mold was printed with a mixture of epoxy resin and rice bran (1:1 w/w) and left for one day. Variation in the fiber mass was at 3, 4, and 5 grams. The sizes of the specimens were similar to the size of the mold according to ASTM D-638 type IV. Then, the fibers were removed from the mold and tested for tensile strength, strain, and Young's modulus. The results show that the greater the fiber mass, the greater the tensile strength value. These findings indicate that the tensile strength was optimized after soaking for 45 minutes with 5-gram fiber weight, which resulted in the tensile strength of 26.32±0.25 MPa, strain of 9.65±0.14%, Young's Modulus of 3.29±0.05 MPa, and water absorption of 41.99%.&lt;/p&gt;

Comparative analysis of early growth phase performance in F3 crossbred Indonesian chickens

Body mass and ratio of feed conversion (FCR) are crucial factors for assessing production potential in local chickens. This study utilized a total of 116 F3 crossbred chickens resulting from the mating of Indonesian local chicken breeds, including Kampung Unggul Balitbangtan, Murung Panggang, Merawang Bangka, and Merawang Sembawa. The chickens were divided into six crossbred groups: BS1 (n = 19), BS2 (n = 19), BS3 (n = 20), BS4 (n = 19), BS5 (n = 20), and BS6 (n = 19), all managed under uniform conditions. Measurements of body mass and feed consumption during the pre-starter phase were taken at weeks 0, 1, 2, 3 and 4 using a digital scale. Data from this study were subjected to ANOVA analysis, followed by a Duncan multiple range test The findings showed notable variations in body mass and FCR among all BS chicken groups (P < 0.05). Notably, BS5 exhibited the highest performance in both body mass and FCR analyses, achieving 392.50 ± 42.76g at week 4, and an overall FCR of 2.01 ± 0.80.

Rates of heat, mass and momentum transfer in a magnetic nanofluid near cylindrical surface with velocity slip and convective heat transfer

The main attention of this study is to give analytic investigation on the behavior of a nanofluid transport rates in response to a continuous variation of parameters. After reducing the governing boundary layer equations in to a set of convenient ordinary differential forms, the efficient optimal homotopy analysis method has been successfully implemented to the set of nonlinear problems. In this analysis, it is found that significant variations of heat, mass and momentum transfer rates are identified with the changes in the values of magnetic field, porosity parameter and diffusion thermo effects. Among other things, the findings of this study will contribute for better understanding and predicting of fluid transport rates near cylindrical surfaces. This will help both theoretical scientists and practical engineers to estimate the degree to which various factors affect the quality of manufacturing products.

Synthesis and characterization of graphene oxide as dielectric material for parallel plate capacitor

Graphite acts as an electrical conductor due to the delocalization of electrons between the surfaces. Graphene oxide (GO) is produced by using graphite via the Hummers method. Reduced GO (rGO) is a form of GO where the oxygen content has been reduced due to chemical, thermal, and other processes. In this study, we have produced a prototype of capacitors containing the synthesized rGO with variation of the rGO mass, i.e.: 0 g., 0,2 g; and 0,8 g. Than we compare the capacitance values obtained from the capacitors using a multitester. Characterizations of the rGO are conducted using XRD, UV-Vis, and FTIR. The results of the UV-Vis test show peak at a wavelength of 300 nm indicating absorption of rGO. The XRD test shows a transition from GO to rGO in an amorphous phase. Finally, the FTIR tests produce transmittance bands from the functional groups of CO2, CO, and OH. This paper shows that the capacitance values of the capacitor using rGO material is greater than using graphite material. It means that rGO is capable of storing more charges than graphite. The highest capacitance value is obtained for the capacitor with 0.2 g rGO, i.e.: 165,02 µF.

Effects of Andrade and Burgers rheologies on glacial isostatic adjustment modeling in Antarctica

Variations in ice mass deform the Earth and modify its gravity field, a process known as Glacial Isostatic Adjustment (GIA). GIA in Antarctica remains poorly constrained due to the cumulative effect of past and present ice-mass changes, the unknown history of the past ice-mass change, and the uncertainties on the mechanical properties of the Earth. This paper investigates the effect of using Andrade and Burgers viscoelastic rheologies, rather than the commonly used Maxwell rheology, to model GIA-induced deformation in Antarctica. The Love number and Green's function formalism are used to compute the radial surface displacements and the gravity changes induced by the past and present ice-mass changes. We consider an Earth model whose elastic properties and radial structure are averaged from the Preliminary Reference Earth Model and two viscosity profiles to account for the recently published results on the present ice-mass changes. Using the three rheological laws affects the temporal response of the Earth differently, leading to smaller discrepancies than those induced by the two viscosity structures. The differences are the largest between Maxwell and Burgers rheologies during the 100–1000 years following the beginning of the surface-mass change. Results show that using the Andrade and Burgers rheologies allows the Earth to respond on decennial to centennial time scales, up to 10 m more than Maxwell. Considering only the recent ice-mass changes, the deformation rates derived from Burgers and Andrade rheologies are several times larger than those estimated by Maxwell rheology.