Coverage Of Deposits Research Articles

Interfacial pressure improves calendar aging of lithium metal anodes

Lithium (Li) metal is a promising anode because its theoretical specific capacity is approximately ten times larger than graphite. However, Li anodes suffer from long-term capacity fade due to Li stranding (becoming electronically disconnected) and electrolyte decomposition. Applied interfacial pressure has been shown to improve Li anode cycling, likely due to reincorporating stranded or “dead” Li into the anode. Calendar aging can also lead to Li capacity loss due to electrolyte decomposition/Li corrosion and the formation of stranded Li. Some research suggests that calendar aging during cycling results in reversible capacity losses due to Li stranding and reconnection. We here investigate the effect of applied interfacial pressure on Li anode calendar aging during cycling with incorporated rest steps in a localized high-concentration electrolyte (LHCE) to understand if pressure can mitigate stranded Li formation during rest by manipulating the Li morphology. Pouch cells exhibit more stable cycling and denser Li deposits between 10 kPa and 1,000 kPa of applied pressure compared to no applied pressure. Despite drops in CE during periodic rest cycles, the average cumulative lost capacity and average coulombic efficiency (CE) of cells over 50 cycles show that cells aged with incorporated rest steps perform similarly to cells cycled without added rests. This similar average CE suggests that dead Li is largely responsible for drops in CE during rest rather than irreversible Li corrosion and that the dead Li can be reconnected in subsequent cycling. The addition of a lithiophilic ZnO coating to the Cu working electrode increases the adhesion and coverage of Li deposits at low pressures and improves CE during the first cycle.

THE BANKING SYSTEM OF UKRAINE IN WARTIME

This article aims to assess changes in the banking system of Ukraine in 2022 under martial law (at the macro level) and the vulnerability of banks to financial stress (at the micro level). The proposed method uses cluster analysis of the main ratios for banking stability based on the agglomerative hierarchical clustering algorithm.The analysis of changes at the macro level under martial law shows that anti-stress measures ensured that a significant negative stress reaction was avoided. The analysis of the vulnerability of banks to financial stress shows that a significant number of banks had problems with funding and turned to the Central Bank, but by the end of the year, the funding market had stabilized. The worst situation concerned non-performing loans, but most of those are covered by reserves. Changes in legislation in Ukraine under martial law provided almost 100% coverage of household deposits in banking institutions.

Intra-seasonal variability in supraglacial stream sediment on the Greenland Ice Sheet

On the surface of the Greenland Ice Sheet, the presence of low-albedo features greatly contributes to ablation zone meltwater production. Some of the lowest albedo features on the Ice Sheet are water-filled supraglacial stream channels, especially those with abundant deposits of consolidated cryoconite sediment. Because these sediments enhance melting by disproportionately lowering albedo, studying their spatial extent can provide a better understanding of Greenland’s contribution to global sea level rise. However, little is known about the spatial distribution of supraglacial stream sediment, or how it changes in response to seasonal flow regimes. Here, we surveyed a supraglacial stream network in Southwest Greenland, collecting imagery from seven uncrewed aerial vehicle (UAV) flights over the course of 24 days in 2019. Using Structure-from-Motion-generated orthomosaic imagery and digital elevation models (DEMs), we manually digitized the banks of the supraglacial stream channels, classified the areal coverage of sediment deposits, and modeled how the terrain influences the amount of incoming solar radiation at the Ice Sheet surface. We used imagery classified by surface types andin-situspectrometer measurements to determine how changes in sediment cover altered albedo. We found that, within our study area, only 15% of cryoconite sediment was consolidated in cryoconite holes; the remaining 85% was located within supraglacial streams mostly concentrated on daily inundated riverbanks (hereafter termed floodplains). Sediment cover and stream width are highly correlated, suggesting that sediment influx into supraglacial drainage systems widens stream channels or darkens previously widened channels. This reduces albedo in floodplains that already receive greater solar radiation due to their flatness. Additionally, the areal extent of stream sediments increased in August following seasonal peak flow, suggesting that as stream power decreases, more sediment accumulates in supraglacial channels. This negative feedback loop for melting may delay Greenland’s runoff to the latter end of the melt season. This study shows in unprecedented detail where and when sediment is deposited and how these deposits potentially impact the Ice Sheet surface energy balance. These findings may allow for better prediction of how supraglacial floodplains, and the microbiomes they contain, might change in response to increased melting.

On the Hedging of Interest Rate Margins on Bank Demand Deposits.

In recent years, we have seen a very rapid increase in outstanding bank deposits. This increase has been particularly high since the outbreak of the COVID 19 pandemic, due to the lockdown that has, among other things, drastically reduced household consumption since the beginning of March 2020. This very sharp increase in outstandings increases the risk of banks which offer interest on deposits. In this paper, we deal with the mitigation of the risk contained in interest rate margins of demand deposits. We introduce and analyze hedging strategies of an asset and liability manager who focuses on the bank’s net operating income in a given quarter under standard accounting rules. Demand deposits are assumed to be correlated with market interest rate and to a commercial risk that cannot be fully hedged on the financial markets. We distinguish several types of dynamic hedging strategies based on both quadratic and quantile criteria. We provide explicit formula for all hedging strategies and we discuss their respective robustness. We show in particular that the quantile hedging criterion leads to somewhat riskier strategy since its gain may be nil, due to its knockout feature. We argue that our contribution establishes a stronger basis for the coverage of bank deposits, which is particularly important in the context of the COVID-19 pandemic and its economic consequences.

Investigation of Electrolyte-Dependent Carbonate Formation on Gas Diffusion Electrodes for CO2 Electrolysis.

The electrochemical reduction of CO2 (ECO2R) is a promising method for reducing CO2 emissions and producing carbon-neutral fuels if long-term durability of electrodes can be achieved by identifying and addressing electrode degradation mechanisms. This work investigates the degradation of gas diffusion electrodes (GDEs) in a flowing, alkaline CO2 electrolyzer via the formation of carbonate deposits on the GDE surface. These carbonate deposits were found to impede electrode performance after only 6 h of operation at current densities ranging from -50 to -200 mA cm-2. The rate of carbonate deposit formation on the GDE surface was determined to increase with increasing electrolyte molarity and became more prevalent in K+-containing as opposed to Cs+-containing electrolytes. Electrolyte composition and concentration also had significant effects on the morphology, distribution, and surface coverage of the carbonate deposits. For example, carbonates formed in K+-containing electrolytes formed concentrated deposit regions of varying morphology on the GDE surface, while those formed in Cs+-containing electrolytes appeared as small crystals, well dispersed across the electrode surface. Both deposits occluding the catalyst layer surface and those found within the microporous layer and carbon fiber substrate of the electrode were found to diminish performance in ECO2R, leading to rapid loss of CO production after ∼50% of the catalyst layer surface was occluded. Additionally, carbonate deposits reduced GDE hydrophobicity, leading to increased flooding and internal deposits within the GDE substrate. Electrolyte engineering-based solutions are suggested for improved GDE durability in future work.

Electroless, diffusion limited aggregation of lead dendrites

• Lead dendrites with fractal characteristics deposit from lead nitrate gel solutions using metallic zinc. • The mechanism of lead fractal formation is explained in the Diffusion Limited Aggregation context. • Fractal dimension and percent coverage of the aggregates have similar variation trend. Two-dimensional lead Pb dendritic systems are prepared by electroless deposition from a lead nitrate gel solution and a zinc Zn metal cylinder in a circular cell. The box counting method is used to confirm that the lead dendritic structures obtained have fractal character. Results show that the fractal dimension of the dendrites formed is affected by the lead nitrate concentration and the medium properties which is varied by changing the percentage of gelatin in the solution. Both variables affect migration and aggregation of the lead particles and hence the physical emergence of the system. It was found that the fractal dimension has a maximum value for the aggregate formed from 0.06 M Pb(NO 3 ) 2 in 5 % gelatin. In addition, the percent coverage of the lead deposits was determined and showed analogous variation with the fractal dimension over the range of Pb(NO 3 ) 2 concentration and gelatin percentage studied.

Assessment of deforestation impact on soil erosion in loess formation using 137Cs method (case study: Golestan Province, Iran)

Golestan, a province in the North-East of Iran, is characterized by high coverage of loess deposits. Since 1963, the area has experienced approximately 200,000 ha deforestation due to land-use changes in agriculture and increasing demand for wood. Approximately, 110,000 ha of the clear-cut lands are under dry-farming, mainly for wheat cropping, and about 86,000 ha have been reforested. This IAEA funded project is the first attempt to use nuclear techniques in the East of Hircanian Forest for determination of on-site impacts of deforestation due to two land-use changes (i.e. dry farming and reforestation). Practicing long-term dry-farming led to 60% soil losses with a mean rate of 2 mm per year. The net erosion rate of croplands on loess deposits in the study area was 32.27 t ha−1 yr−1. Reforestation, cultivation of even-aged Cypress trees since 1993, showed 13 to 60 percent effectiveness in soil conservation. Dry-farming land use resulted in the loss of 95 t ha−1 soil organic carbon (SOC) stock at a mean rate of 1.7 t ha−1 over 54 years. Cultivating Cypress trees successfully restored the SOC content by 100% compared with the SOC in original forests. The conversion of dry-farming lands to orchards of olive trees since 2004, brought more income for farmers but were less effective in soil conservation because of low canopy cover of olive trees. Our data provide key information and guidance for land users and decision-makers about implementing strategic and sustainable conservation practices to restore degraded land.

THE BASEL III REGULATORY FRAMEWORK AND ITS IMPLICATION ON THE LIQUIDITY OF THE BANKING SECTOR IN THE REPUBLIC OF NORTH MACEDONIA

The advent of the global financial crisis and its consequences have led the banking system to work towards more stringent regulatory rules. Additional regulatory requirements affect various aspects of banks' operations. In this regard, one of the most important questions that arises is how the implementation of the new Basel III regulatory framework affects the liquidity of banking institutions.The focus in this paper is the liquidity of the banks in the Republic of Northern Macedonia. The subject of the study is focused on the strength and direction of the impact of the new Basel III regulatory framework on their liquidity. The aim of the study is to reveal the effect of the use of modern regulatory requirements on liquidity of the banking system. A coefficient analysis is applied using a system of appropriately selected indicators: change (increment or decrease) of liquid and highly liquid assets, relative share of liquid and highly liquid assets in the structure of assets, coverage of liabilities with liquid assets, coverage of short-term liabilities with liquid assets, coverage of deposits by non-financial entities with liquid assets, “loans / deposits” ratio.The study includes observations on developments in the banking sector of the Republic of Northern Macedonia for the period 2007-2018. In terms of the impact of the new regulatory framework on banking liquidity, the twelve-year period analysed includes three distinct phases: 1) the time before the onset of the global financial crisis (until 2009); 2) the crisis period (2009 to 2012); 3) the post-crisis period (after 2012), during which the new regulatory measures are gradually moving (Basel III). For the purposes of the study, two working hypotheses are formulated: 1) first hypothesis - the new rules for regulating liquidity and capital adequacy have a negative or stagnant effect on the liquidity of banks in the Republic of Northern Macedonia, manifested in the form of sensitive fluctuations or in the form of sensitive fluctuations or a number of their financial liquidity indicators; 2) second hypothesis - the implementation of the new regulatory measures does not adversely affect banks' liquidity. The analysis of real empirical data shows that the implementation of the new regulatory measures does not have a negative impact on the liquidity of banks in the Republic of Northern Macedonia, but rather, a tendency to stabilize and improve a number of their key liquidity indicators.

Shallow Shear-Wave Velocity Beneath Jakarta, Indonesia Revealed by Body-Wave Polarization Analysis

Noting the importance of evaluating near-surface geology in earthquake risk assessment, we explored the application to the Jakarta Basin of a relatively new and simple technique to map shallow seismic structure using body-wave polarization. The polarization directions of P-waves are sensitive to shear-wave velocities (Vs), while those of S-waves are sensitive to both body-wave velocities. Two dense, temporary broadband seismic networks covering Jakarta city and its vicinity were operated for several months, firstly, from October 2013 to February 2014 consisting of 96 stations, and secondly, between April and October 2018 consisting of 143 stations. By applying the polarization technique to earthquake signals recorded during these deployments, the apparent half-space shear-wave velocity (Vsahs) beneath each station is obtained, providing spatially dense coverage of the sedimentary deposits and the edge of the basin. The results showed that spatial variations in Vsahs obtained from polarization analysis are compatible with previous studies, and appear to reflect the average Vs of the top 150 m. The low Vs that characterizes sedimentary deposits dominates most of the area of Jakarta, and mainly reaches the outer part of its administrative margin to the southwest, more than 10 km away. Further study is required to obtain a complete geometry of the Jakarta Basin. In agreement with previous studies, we found that the polarization technique was indeed a simple and effective method for estimating near-surface Vs that can be implemented at very low-cost wherever three-component seismometers are operated, and it provides an alternative to the use of borehole and active source surveys for such measurements. However, we also found that for deep basins such as Jakarta, care must be taken in choosing window lengths to avoid contamination of basement converted phases.

Limited deposit insurance coverage and bank competition

Abstract Deposit insurance designs in many countries place a limit on the coverage of deposits in each bank. However, no limits are placed on the number of accounts held with different banks. Therefore, under limited deposit insurance, some consumers open accounts with different banks to achieve higher or full deposit insurance coverage. We compare three regimes of deposit insurance: no deposit insurance, unlimited deposit insurance, and limited deposit insurance. We show that limited deposit insurance weakens competition among banks and reduces total welfare relative to no or unlimited deposit insurance.

Magnetorheology of hybrid colloids obtained by spin-coating and classical rheometry

Hybrid colloids composed of micron-sized ferromagnetic (carbonyl iron) and diamagnetic (silica) particles suspended in cyclohexanone, behave as, non-Newtonian, magnetorheological fluids. We measure and compare the magnetic field-dependent viscosity of hybrid diluted colloids using spin-coating and conventional magnetorheometry. We extend a previously developed model for simple colloids to this kind of hybrid colloids. As in the previous model, the viscosity of the colloidal suspension under applied fields can be derived from the surface coverage of the dry spin-coated deposits for each type of particles, and from the viscosity of the colloid at zero field. Also, our results allow us to obtain the evaporation rate of the solvent as a function of the rotation speed. Finally, we also measure the viscosity of the same suspension with a torsional parallel plate magnetorheometer under uniaxial DC magnetic fields aligned in the velocity gradient direction of a steady shearing flow. The experimental results under different conditions and the effect of each component on the magnetorheological properties of the resulting colloid are discussed. Standard spin-coating technique can be used both to characterize smart materials—complex fluids as well as to fabricate films with arbitrary solvents by tuning their viscosity by means of external fields.

A Review of Bank Funding Cost Differentials

The debate over the existence and extent of funding cost differentials between large and small banks is central to regulatory reforms related to perceptions of “too big to fail” government support. After providing a simple taxonomy of five basic approaches into which the wide-ranging empirical literature on this topic can be categorized, I analyze key challenges that all of the approaches face, namely, the interpretation of funding costs differences between large and small banks, the choice of the relevant time period, the choice of the sample, and the significant differences in the funding structures of large and small banks. After analyzing further more specific challenges for three of the approaches, I describe the most promising methods for measuring funding cost differentials and present a “natural experiment” concerning the elimination of complete FDIC coverage of transactions deposits at the end of 2012, which suggests that depositors did not perceived a significant difference in risk between large and small banks during this period.

СТІЙКІСТЬ БАНКІВСЬКОЇ СИСТЕМИ УКРАЇНИ В КОНТЕКСТІ ВНУТРІШНІХ ТА ЗОВНІШНІХ ВИКЛИКІВ

У статті досліджено ключові загрози вітчизняній банківській системі та їх можливі наслідки у контексті порушення стійкості банків. Виявлено головні джерела проблем і небезпек та визначено можливі заходи з їх нейтралізації. Досліджено рівень капітальної стійкості, проаналізовано якість кредитного портфелю та здійснено оцінку ризиків неплатоспроможності вітчизняних банків. Проаналізовано достатність коштів ФГВФО для здійснення виплат вкладникам потенційних банків-банкрутів.

Study of the inhibition effect of two polymers on calcium carbonate formation by fast controlled precipitation method and quartz crystal microbalance

In this paper, the inhibition efficiency of two inhibitors, namely poly(acrylic acid-co-maleic acid) and polyaspartic acid, towards calcium carbonate scaling was evaluated using fast controlled precipitation (FCP) method and electrochemical quartz crystal microbalance (EQCM). FCP method gave some insight to the calcium carbonate precipitation in solution, whereas EQCM was used to study the calcium carbonate formation on a metallic substrate. It has been shown that these polymers were efficient to delay or to prevent nucleation/growth process, depending on their concentration. Moreover they significantly decreased the crystal growth rate. The FCP method showed that these inhibitors were very efficient at low concentrations (4mgL−1) when no precipitation occurred. In addition, EQCM showed that the surface coverage of deposits on a substrate was reduced by the presence of these inhibitors at very low concentration (4mgL−1). Scanning electronic microscopy and X-ray diffraction showed that the presence of these polymers modified the morphology of calcium carbonate crystal. In order to model nucleation/growth process of calcium carbonate on surface, mass–time transients were interpreted using a 3D model based on a nucleation following a Poisson law associated to vertical and lateral growth rates.

Influence of wall friction on flow regimes and scale-up of counter-current swirl spray dryers

The structure of the vortex flow in swirl spray dryers is investigated after having fouled the walls with deposits typical of detergent manufacture. The range of Re and swirl intensity Ω characteristic of industry are studied using three counter-current units of varying scale and design. The friction with the deposits increases the flow turbulence kinetic energy and causes a drastic attenuation of the swirl and as a result, the vortex breaks down in the chamber forming recirculation regions (i.e. areas of reverse flow). Three flow regimes (1) no recirculation, (2) central and (3) annular recirculation have been identified depending on the swirl intensity. New control and scale up strategies are proposed for swirl dryers based in predicting the decay and the flow regime using the unit geometry (i.e. initial swirl intensity Ωi) and experimental decay rates function of the coverage and thickness of deposits. The impact in design and numerical modelling must be stressed. Adequate prediction of the swirl is vital to study fouling and recirculation, which surely play an important part in the dispersion and aggregation of the solid phase. Current models have no means to replicate these phenomena, and yet, in this case neglecting the deposits and assuming smooth walls would result in (a) over-prediction of swirl velocity up to 40−186% (b) under-prediction of turbulent kinetic energy up to 67−85% and (c) failure to recognise recirculation areas.

Galvanostatically-electrodeposited Cu–Zn–Sn multilayers as precursors for crystallising kesterite Cu2ZnSnS4 thin films

Metallic stacked layers containing Cu, Zn and Sn on Mo-coated glass substrates were prepared by galvanostatic electrodeposition as precursors for crystallising kesterite Cu2ZnSnS4 films. Due to the nature of the MoOx passivating layer on the Mo surface, initial trials were particularly addressed to deposit strong adhesive precursors by firstly depositing Cu layers on Mo-coated substrates from acidic as well as alkaline solutions. It was found that the acidic Cu solutions were not appropriate for the Cu deposition on Mo-coated glass substrates, since they led to an inhomogeneous coverage of the Cu deposits in addition to extremely poor adhesion. In contrast, utilising an alkaline Cu solution yielded a homogeneous coverage of the Cu deposits, having strong adhesion to the Mo-coated glass substrates, which was essential for the subsequent acidic Zn or Sn galvanostatic electrodepositions. The crystallisation of kesterite Cu2ZnSnS4 from metallic stacked Cu/Sn/Zn precursors was investigated as well. The sulfurisation process crystallises the Cu–Zn–Sn precursor films into films exhibiting predominant kesterite phase. This result demonstrates that the established galvanostatic electrodeposition technique for metals has a technological potential for preparing kesterite precursors.

Limited Deposit Insurance Coverage and Bank Competition

Deposit insurance schemes in many countries place a limit on the coverage of deposits in each bank. However, no limits are placed on the number of accounts held with different banks. Therefore, under limited deposit insurance, some consumers open accounts with different banks to achieve higher or full deposit insurance coverage. We compare three regimes of deposit insurance: No deposit insurance, unlimited deposit insurance, and limited deposit insurance. We show that limited deposit insurance weakens competition among banks and reduces total welfare relative to no or unlimited deposit insurance.

Limited Deposit Insurance Coverage and Bank Competition

Deposit insurance schemes in many countries place a limit on the coverage of deposits in each bank. However, no limits are placed on the number of accounts held with different banks. Therefore, under limited deposit insurance, some consumers open accounts with different banks to achieve higher or full deposit insurance coverage. We compare three regimes of deposit insurance: No deposit insurance, unlimited deposit insurance, and limited deposit insurance. We show that limited deposit insurance weakens competition among banks and reduces total welfare relative to no or unlimited deposit insurance.

Limited Deposit Insurance Coverage and Bank Competition

Deposit insurance designs in many countries place a limit on the coverage of deposits in each bank. However, no limits are placed on the number of accounts held with different banks. Therefore, under limited deposit insurance, some consumers open accounts with different banks to achieve higher or full deposit insurance coverage. We compare three regimes of deposit insurance: No deposit insurance, unlimited deposit insurance, and limited deposit insurance. We show that limited deposit insurance weakens competition among banks and reduces total welfare relative to no or unlimited deposit insurance.

Study of Platinum Deposition on Untreated and Thermally Modified Glassy Carbon

Platinum was deposited from aqueous sulphuric acid solution of hexachloroplatinic acid under potentiostatic conditions upon untreated as well as thermally treated glassy carbon (GC). The influence of thermal treatment of GC on electrochemical platinum deposition was thoroughly investigated in terms of the size, the size distribution and coverage of Pt deposits, using scanning electron microscopy and X-ray photoelectron spectroscopy. A decrease in Pt particle diameter and an increased Pt coverage was observed for various deposition pulse lengths on thermally pre-treated GC. This thermal pre-treatment led to a formation of a microporous layer on the substrate surface, thus influencing particle size distribution and coverage. Atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS) measurements have shown that the chemical composition and surface roughness of GC are not affected by the treatment.