Optimal Consumption Rate Research Articles

Study of the corrosion protection effect of the new composition based on gossypol resin in the hydrogen sulfide formation water

We investigated the impact of a new composition (HS-1) composed of gossypol resin and IB-1 reagent taken in the ratio of 3:1 on the corrosion rate in the hydrogen sulfide formation water under laboratory conditions. Concentrations of 20, 40, 60 and 80 mg/l of the new composition were used. The formation water sample taken from well No. 1082 of "Bibiheybatneft" OGPD, SOCAR was used as an corrosion medium. The corrosion effects were also investigated at the concentrations of 50, 100, 150 and 200 mg/l of gossypol resin and 10, 15, 20 and 25 mg/l of IB-1 inhibitor. When the concentration of gossypol resin in the formation water increased by 50–200 mg/l, the corrosion protection effect took a value in the range of 60–82%. When the concentration of IB-1 inhibitor varied between 10–25 mg/l in a hydrogen sulfide medium, the protection effect was between 65–90%. Increasing the concentration of new HS-1 composition in the range of 30–80 mg/l resulted in an increase in its corrosion protection effect between 74–98%. It was found that the optimal consumption rate of gossypol resin, IB-1 inhibitor and HS-1 composition for corrosion protection in an aggressive medium with hydrogen sulfide was 200 mg/l, 25 mg/l and 80 mg/l, respectively.

Элементы технологии применения лабораторных образцов смесевых микробиологических препара-тов в препаративной форме смачивающийся порошок на основе перспективных штаммов антагонистов на фоне естественного поражения масличного льна фузариозом в полевых условиях

In 2022, laboratory samples of mixed microbiological preparations in a preparative form wettable powder (WB) based on promising strains-producers were tested in the laboratory of biological methods at the V.S. Pustovoit All-Russian Research Institute of Oil Crops in field conditions under natural infection of oil flax with fusariosis. We determined the optimal consumption rates the laboratory samples of WB of the mixed microbiopreparations based on different ratios (1 : 1; 1 : 2; 1 : 3) of promising fungal T-1 Trichoderma sp. and bacterial 11-3 Bacillus sp. components. A chemical etalon Redigo Pro had no protective effect at a middle level of fusariosis infection (25.9%) on oil flax variety VNIIMK 620 in control variant without microbiopreparations treatment. The biological etalons based on a separate producer had the biological efficiency against disease for a fungal strain with a consumption rate of 0.05 kg/t – 66.0% with a low additional yield of 0.17 t/ha, and for a bacterial strain with a consumption rate of 0.2 kg/t – 40.5% with additional yield 0.24 t/ha. The optimal consumption rate of the laboratory samples WP of the mixed microbiopreparations in all test variants of ratios be-tween fungal and bacterial components id 0.3 kg/t. At this consumption rate of wettable powder, ratio 1 : 1 had the biological efficiency against fusariosis 54.8% with an additional yield of 0.44 t/ha; ratio 1 : 2 had a protective effect of 40.5% and additional yield of 0.23 t/ha; the biological efficiency of a ratio 0 : 3 was 56.0% with an additional yield of 0.54 t/ha.

Влияние режимов лазерной наплавки на геометрические размеры стального трека

Introduction. Laser surfacing is one of the leading trends in the field of additive technologies, which consists in layer-by-layer build of material using a laser as an energy source. To obtain a high-quality product, it is necessary to select the optimal building parameters correctly. The problem is that such optimization is necessary for all equipment, since minor differences in its characteristics can make significant changes in the parameters of layer-by-layer build. In order to determine the optimal build mode, it is enough to analyze the effect of various equipment parameters on the characteristics of single tracks. Therefore, the purpose of this work is to determine the most important parameters of laser radiation that affect the surfacing process and the optimal mode for building a single track of chromium-nickel steel. The work investigated single tracks obtained by laser surfacing of powder from austenitic chromium-nickel steel AISI 316L. The optimization factors included such characteristics as laser power, beam speed, flow rate of supplied powder and laser spot size. The wavelength of laser radiation was 1.07 μm. Research methods. To determine the quality and geometric dimensions of single tracks, the macrostructure of cross sections of specimens was studied using metallography and scanning electron microscopy methods. Results and discussion. It is established that the optimal mode for growing single tracks of steel AISI 316L is characterized by a laser radiation power of 1,250 W and a scanning speed of 25 mm/s. In this case, the optimal powder consumption rate is 12 g/min, and the laser spot size is 4.1 mm. The work shows that the powder consumption and laser spot size have the greatest influence on the coefficient of effective use of powder material. By changing it, the surfacing performance can be increased by 10–15 %.

Badania wielofunkcyjnych właściwości nowej kompozycji o nazwie AZ-1

This article presents the results of the study of multifunctional properties of a new composition, with the conventional name AZ-1, which was prepared from various reagents under laboratory conditions. For this purpose, the results of its effect on a number of rheological parameters of commodity oil and the corrosion rate in hydrogen sulphide formation water have been interpreted. Laboratory experiments were conducted using concentrations of 100, 300, 500, 700 and 900 g/t of the composition, all following established standard methods. For the research purposes, the oil sample was taken from Narimanov field of SOCAR, and the aggressive medium was hydrogen sulphide formation water taken from well No. 1082 of “Bibiheybatneft” OGPD. Numerous experiments have shown that the optimum consumption rate of AZ-1 composition is 700 g/t. AZ-1 composition reduces the freezing temperature from +14°C to –8°C by improving the fluidity of the studied oil sample at optimal viscosity. The value of the shear stress limit of the anomalous oil sample is also drastically reduced. During the experiments carried out using the “cold finger test” method, it was found that AZ-1 composition has a high effect on oil deposits. At the temperature of +5°C of the “cold finger test”, its efficiency was 90% at the optimal consumption rate. During the effect of AZ-1 composition on the corrosion rate in hydrogen sulphide formation water, the protection effect increases at the concentration of 100–700 g/t and varies between 85–98%. At 900 g/t, the value of the protective effect is relatively reduced to 82%, and this is an indicator that the optimum consumption rate of AZ-1 composition is 700 g/t.

Enhancing demulsification efficiency and corrosion protection in oil industry: a study of novel compositions

In countries with developed oil industries, the primary objective is to effectively implement the demulsification of water-oil emulsions and provide corrosion protection for facilities during the preparation of heavy oils with stable emulsions for transportation. Consequently, the development of new multi-functional compositions to enhance the efficiency of the emulsion decomposition process and protect the internal surfaces of transport preparation facilities from corrosion remains a pertinent issue. The article presents the results of laboratory experiments on the demulsification of stable water-oil emulsions from the Muradkhanli field in Azerbaijan, which have a dilution rate of 41% (by mass) and provides satisfactory corrosion protection. For the first time, compositions comprising two new ingredients (Alkan-415+Gossypol resin in a 4:1 ratio (denoted as G-1) and Alkan-415+MARZA-1 in a 7:1 ratio (denoted as G-2)) were prepared under laboratory conditions, and their demulsification and corrosion protection effects in an acidic environment were studied. The demulsification process was conducted at temperatures of 50 and 600C for two hours. During the examination of the demulsification efficiency of the compositions, it was observed that the effectiveness of the reagents increased with higher concentrations. At temperatures of 50 and 600C, the most significant effects were observed at a concentration of 700 g/t for both compositions. At these temperatures, the residual water content due to the effect of the G-1 composition was 0.02% and 0.01%, and for the G-2 composition, it was 0.01% and 0.005%, respectively. Furthermore, the corrosion protection efficiency of both G-1 and G-2 compositions in an acidic environment was investigated. During the experiment, the highest effectiveness was observed at a concentration of 700 g/t for both compositions. At this concentration, the corrosion protection effect of the G-1 composition was 96%, while that of the G-2 composition was 98%. Thus, it was determined that, due to their multifunctionality and significant impact both in the decomposition of stable water-oil emulsions and in acidic environments, the optimal consumption rates of both compositions with new content are 700 g/t.

Optimal configuration of energy storage system capacity in traction power supply system considering photovoltaic consumption

In order to achieve energy savings and promote on-site integration of photovoltaic energy in electrified railways, a topology structure is proposed for the integration of photovoltaic (PV) and the energy storage system (ESS) into the traction power supply system (TPSS) based on a railway power conditioner (RPC). This paper analyzes the composition and operation principles of this structure. To assess the economic benefits brought by the integration of photovoltaic and energy storage systems, a bilevel optimization model is established, with the objectives of optimizing energy storage capacity configuration and photovoltaic energy integration. The KKT (Karush–Kuhn–Tucker) method is employed to transform the model into a single-layer mixed-integer linear programming model, which is then solved using the CPLEX solver in MATLAB. The research findings indicate that, with the configuration of the ESS, the optimal PV consumption rate achieved is 96.8749%. Compared to a 100% PV consumption rate, the ESS capacity configuration is reduced by 13.14%, and the overall operational cost of the TPSS is at its lowest. The study suggests that the proposed bilevel optimization algorithm can more effectively consider PV consumption, leading to enhanced economic performance of the TPSS operation.

Zastosowanie nowych skutecznych kompozycji do rozdzielania stabilnej emulsji wodno-ropnej

A sample of crude oil from Umbaki oil field, characterized by the property of forming an aggregative and kinetically stable water-oil emulsion has been studied in the work. To conduct the research, Dissolvan-4411, Difrol-9426, Sarol-412, Dissolvan-13280 and ND-12 demulsifiers were examined at concentrations of 200, 400 and 600 g/t and the optimal consumption rate was determined. Laboratory experiments were carried out at temperatures of 20, 40 and 60°C. 10 compositions were prepared with a 1:1 ratio of each reagent, based on the optimal consumption rate of 600 g/t. The compositions are reagents with the same purpose, prepared on the basis of demulsifiers. New compositions of W-series were prepared on the basis of the most preferred compositions of A-series. The efficiency of demulsification was investigated, and, experiments were carried out to measure the quantities of asphaltene, resin and paraffin sediments, as well as the remaining amounts of salts and mechanical mixtures after demulsification of oil. The results of the conducted experimental studies revealed that the effect of compositions is superior to the effect of individual reagents. This is explained by the synergism effect between the reagents. As a result, the impact of compositions on the rheology of stable water-oil emulsions becomes stronger. The amount of chloride salts, mechanical mixtures and asphaltene-resin-paraffin compounds in the oil also decreases sharply. Finally, the dependence of the thickness of the best-performing W series compositions on viscosity, which is an important rheological parameter of oil, is shown in a diagram. The W-2 composition is recommended for wide application in mining conditions as a multifunctional reagent in the oil industry.

Działanie antykorozyjne wybranych odczynników na korozję stali węglowej w wodzie złożowej zawierającej siarkowodór

For the first time, the impact of the composition of gossypol resin and IB-1 reagent, prepared in a 3:1 ratio and conventionally named HS-1, on the corrosion rate in hydrogen sulfide formation water has been investigated under laboratory conditions. Concentrations of 20, 40, 60, 80 mg/l of the new composition were used. During the experiments, a formation water sample taken from well No. 1082 of “Bibiheybatneft” OGPD, SOCAR, served as the electrochemical corrosion medium for the study. To conduct a comparative analysis, gossypol resin, IB-1 inhibitor, and HS-1 composition were used. Concentrations of 50, 100, 150, 200 mg/l of gossypol resin and 10, 15, 20, and 25 mg/l of IB-1 inhibitor were employed in the experiments. Numerous laboratory experiments revealed that the optimal consumption rate for the HS-1 inhibitor is 100 mg/l, for gossypol resin it is 200 mg/l, and for the IB-1 inhibitor it is 25 mg/l. These experiments were conducted under dynamic conditions over six hours. It was determined that the newly developed HS-1 composition offers superior protection in an aggressive medium containing hydrogen sulfide compared to its constituent components, gossypol resin, and IB-1 inhibitor. Specifically, as the concentration of gossypol resin in formation water increases from 50 to 200 mg/l, the corrosion protection effect ranges from 60–82%. When the concentration of IB-1 inhibitor varies between 10–25 mg/l in a hydrogen sulfide medium, the protection effect lies between 65-90%. In the aggressive medium of hydrogen sulfide formation water, increasing the concentration of the new HS-1 composition from 30–80 mg/l results in an enhancement of its electrochemical corrosion protection effect, ranging from 74–98%. Upon analyzing the results of numerous laboratory experiments, it was found that the optimal consumption rate of gossypol resin for corrosion protection in an aggressive medium with hydrogen sulfide is 200 mg/l, the consumption rate of IB-1 inhibitor is 25 mg/l, and for the HS-1 composition is 80 mg/l. The corrosion rates for gossypol resin in the concentrations of 50, 100, 150, 200 mg/l is 1.72, 1.38, 1.12, 0.78 g/m2 · h and retardation coefficient is 2.50, 3.10, 3.84, 5.51, respectively. Corrosion rate of IB-1 inhibitor concentration in the amount of 10, 15, 20, and 25 mg/l is 1.5, 1.12, 0.78, 0.43, and retardation coefficient is 2.86, 3.84, 5.51, 10.0, respectively. The corrosion rates for the new HS-1 composition at concentrations of 20, 40, 60, 80 mg/l is 1.12, 0.73, 0.34, 0.08, and the retardation coefficient is 3.84, 5.89, 12.64, 53.75, respectively. Comparing the corrosion rate values obtained for all three reagents with the corrosion rate for hydrogen sulphide formation water shows that new HS-1 composition has a higher effectiveness compared to its constituent components.

Роль биостимуляторов роста в получении высококачественного урожая ярового ячменя

In the conditions of the Moscow region in 2020-2021. conducted research aimed at identifying the effectiveness of pre-sowing treatment of spring barley seeds with a growth regulator based on the biomass of living microorganisms, as well as establishing the optimal consumption rate of the drug and the effect of using a growth biostimulator on the crop structure, yield and grain quality of spring barley. The length of the spike was significantly longer in the experimental variants, exceeding the control indicator by 30.3 - 31.9%, the weight of 1000 grains, depending on the dose of the drug, was higher than the control by 2.6% - 4.1%. A significant increase in crop yield was obtained in the variant using Restart Zh at a dose of 0.2 l/t + 0.5 l/ha, amounting to 1.7 c/ha. The protein content in the experiment varied from 11.9% to 12.8%. Keywords: BIOSTIMULANTS, SOWING QUALITIES, SPRING BARLEY, YIELD, CROP STRUCTURE

Effects of the Preferential Oxidation of Phenolic Lignin Using Chlorine Dioxide on Pulp Bleaching Efficiency.

Chlorine dioxide is widely used for pulp bleaching because of its high delignification selectivity. However, efficient and clean chlorine dioxide bleaching is limited by the complexity of the lignin structure. Herein, the oxidation reactions of phenolic (vanillyl alcohol) and non-phenolic (veratryl alcohol) lignin model species were modulated using chlorine dioxide. The effects of chlorine dioxide concentration, reaction temperature, and reaction time on the consumption rate of the model species were also investigated. The optimal consumption rate for the phenolic species was obtained at a chlorine dioxide concentration of 30 mmol·L-1, a reaction temperature of 40 °C, and a reaction time of 10 min, resulting in the consumption of 96.3% of vanillyl alcohol. Its consumption remained essentially unchanged compared with that of traditional chlorine dioxide oxidation. However, the consumption rate of veratryl alcohol was significantly reduced from 78.0% to 17.3%. Additionally, the production of chlorobenzene via the chlorine dioxide oxidation of veratryl alcohol was inhibited. The structural changes in lignin before and after different treatments were analyzed. The overall structure of lignin remained stable during the optimization of the chlorine dioxide oxidation treatment. The signal intensities of several phenolic units were reduced. The effects of the selective oxidation of lignin by chlorine dioxide on the pulp properties were analyzed. Pulp viscosity significantly increased owing to the preferential oxidation of phenolic lignin by chlorine dioxide. The pollution load of bleached effluent was considerably reduced at similar pulp brightness levels. This study provides a new approach to chlorine dioxide bleaching. An efficient and clean bleaching process of the pulp was developed.

What is the value of swappable batteries for a shared e-scooter service?

Swappable batteries have been deployed in several services of dockless shared e-scooters. This article provides an economic theory of swappable batteries in the production of a shared e-scooter service (S3). Explicitly modelled are the operations of battery swapping by “juicing tours”, as well as the wearing law of the electric batteries depending on the depth of discharge (DoD) that triggers the next swap. In the production model, the daily number of refills and the per-refill swapping cost are key variables as they link the field implementation and the swapping logistics functions to the other production functions of battery inventory, scooter inventory, energy charging, fleet maintenance and commercial. Thus the overall “refill strategy” interplays with the respective inventory policies of batteries and of scooters. The mathematical optimization of the production cost function is addressed in four stages, by optimizing in turn (i) the swapping tours, (ii) the target DoD, (iii) the battery energy capacity (BEC), (iv) the scooter body in terms of lifespan and energy consumption rate. Characteristic equations are established for the optimal per-refill cost, DoD, BEC, scooter lifespan and energy consumption rate. Two sets of specifications, namely Constant Elasticity and Affine Linear, are specified for the battery wearing law, the battery price and the scooter price: under either set the model admits an analytical solution. In a numerical study, it is shown that the S3 cost per unit of fed-in energy is one order of magnitude greater than the out-of-the-grid electricity price.

Bequest motives in consumption-portfolio decisions with recursive utility

This paper studies finite-horizon consumption-portfolio decisions with recursive utility. We show that the parameter seemingly representing the individual’s bequest preference in traditional recursive utility formulations is quantitatively and qualitatively misleading. The parameter value is uninformative about the optimal bequest which, in some cases, is even inversely related to the magnitude of the apparent bequest weight. We argue that the ratio between optimal bequest and the optimal consumption rate just before the terminal date is a much better representation of the strength of the bequest motive. Numerical examples illustrate the pitfalls using the traditional specification and clarifies how the bequest preference affects optimal decisions and the life-cycle patterns of consumption and wealth assuming constant investment opportunities or stochastic interest rates. We show that the typical utility representation for a unit elasticity of intertemporal substitution actually assumes a strong bequest preference.

Response of drip fertigated wheat-maize rotation system on grain yield, water productivity and economic benefits using different water and nitrogen amounts

Drip fertigation is beneficial to improve crop grain yield (GY), water productivity (WP) and nitrogen use efficiency (NUE), but it is not clear whether drip fertigation can improve economic benefit and how much water and nitrogen should be applied for wheat-maize rotation system in semi-humid and drought-prone regions. A two-year (2018–2020) winter wheat-summer maize rotation field experiment (including twelve drip fertigation treatments (complete combination design of three irrigation (RF: rain-fed, DI: deficit irrigation, 75% ETc, and FI: full irrigation, 100% ETc) and four nitrogen levels (N0: no nitrogen, N1: 85 kg ha−1 for wheat and 90 kg ha−1 for maize, N2: 170 kg ha−1 for wheat and 150 kg ha−1 for maize) and N3: 255 kg ha−1 for wheat and 210 kg ha−1 for maize)) and a conventional practice (Con)) was conducted to explore the response of GY, NUE, WP and net income to different water and nitrogen levels in the Guanzhong Plain of China. The results showed that water and nitrogen application levels had significant effects on GY, NUE, WP and net income of winter wheat and summer maize. For winter wheat, DIN2 (the combination of irrigation and nitrogen) achieved the highest GY (9.2 t ha−1, two-year average), WP (2.11 kg m−3) and net income (11 839 CNY ha−1). For summer maize, the highest GY (11.1 t ha−1), WP (2.32 kg m−3) and net income (14 859 CNY ha−1) were observed at DIN3, RFN3 and DIN2, respectively. For winter wheat-summer maize rotation system, the highest GY (20.2 t ha−1, winter wheat + summer maize, two-year average) and net income (26 698 CNY ha−1) were observed at DIN2; and the highest WP of 2.15 kg m−3 was obtained at RFN3, but had insignificant difference with DIN2 (2.13 kg m−3) (P > 0.05). Therefore, deficit irrigation coupled with 320 kg N ha−1 (170 kg ha−1 for wheat, 150 kg ha−1 for maize) was considered as the best drip fertigation strategy for achieving high GY, WP and net income in winter wheat-summer maize rotation system. Moreover, the response surface methodology was used to determine the optimal water consumption and nitrogen application rate based on binary quadratic regression analysis. The results showed that the GY and net income can synchronously achieve 95~100% maximum values when the water consumption ranged from 434 to 496 mm and 458–500 mm, and the nitrogen application rate ranged from 165 to 211 kg ha−1 and 187–250 kg ha−1 for winter wheat and summer maize, respectively.

Anchoring of Formamidinium Lead Bromide Quantum Dots on Ti3C2 Nanosheets for Efficient Photocatalytic Reduction of CO2.

Metal halide perovskite with a suitable energy band structure and excellent visible-light response is a prospective photocatalyst for CO2 reduction. However, the reported inorganic halide perovskites have undesirable catalytic performances due to phase-sensitive and severe charge carrier recombination. Herein, we anchor the FAPbBr3 quantum dots (QDs) on Ti3C2 nanosheets to form a FAPbBr3/Ti3C2 composite within a Schottky heterojunction for photocatalytic CO2 reduction. Upon visible-light illumination, the FAPbBr3/Ti3C2 composite photocatalyst exhibits an appealing photocatalytic performance in the presence of deionized water. The Ti3C2 nanosheet acts as an electron acceptor to promote the rapid separation of excitons and supply specific catalytic sites. An optimal electron consumption rate of 717.18 μmol/g·h is obtained by the FAPbBr3/0.2-Ti3C2 composite, which has a 2.08-fold improvement over the pristine FAPbBr3 QDs (343.90 μmol/g·h). Meanwhile, the FAPbBr3/Ti3C2 photocatalyst also displays a superior stability during photocatalytic reaction. This work expands a new insight and platform for designing superb perovskite/MXene-based photocatalysts for CO2 reduction.

Extinguishment of cable fires at packaged transformer substations

Introduction. According to the statistical data, electrical fires account for the majority of all fire accidents. Hence, better fireproofing of fuel and energy facilities is a relevant issue. The article addresses electrical fire extinguishment using high-expansion foam. An extinguishment time analysis methodology, applicable to fire extinguishment using high-expansion foam, has been developed to validate these solutions. The purpose of this article is to calculate the dependence between the fire extinguishment time and the foam consumption rate. The research objectives are to 1) identify the principal values to be used in the calculations and the list of input data; 2) to identify the dependence between the extinguishment time and the foam consumption rate using packaged transformer substation 2BKTP (1,000 kVA) as an example. Calculation methodology. The calculation methodology is based on the material balance equation between the amount of foam, applied for firefighting purposes, and the amount of foam, destroyed as a result of its contact with the heated wire surface, which is the main fire load inside burning electrical facilities. Research results. The co-authors have calculated the fire suppression time using packaged transformer substation 2BKTP (1,000 kVA) as an example. Dependencies between fire extinguishment time, specific foam consumption rate, and foam application rate are identified. Conclusions. The co-authors have identified the main values, needed to simulate a fire extinguishing model. They have also shown optimal foam consumption and application rates and offered their assessment of the applicability of high-expansion foam to electrical fires.

A Stochastic Control Model of Investment and Consumption with Applications to Financial Economics

This study considers a stochastic control model in which an economic unit has productive capital and liabilities in the form of debt. The worth of capital changes over time through investment and random Brownian fluctuations in the unit price of capital. Income from production is also subject to the random Brownian fluctuations. The existence of the solutions to the associated Hamilton Jacobi Bellman equation for this model is established and the optimal policies are characterized. The optimal advertising rate as a function of the market share, the optimal consumption rate and the fraction of the wealth invested in stock at any time are obtained. The worth of the capital and the optimal consumption policy are derived for the stochastic optimal investment consumption model associated with the Hamilton Jacobi Bellman equation. Analysis and numerical simulations are then presented.

A financial market with singular drift and no arbitrage

We study a financial market where the risky asset is modelled by a geometric Itô-Lévy process, with a singular drift term. This can for example model a situation where the asset price is partially controlled by a company which intervenes when the price is reaching a certain lower barrier. See e.g. Jarrow and Protter (J Bank Finan 29:2803–2820, 2005) for an explanation and discussion of this model in the Brownian motion case. As already pointed out by Karatzas and Shreve (Methods of Mathematical Finance, Springer, Berlin, 1998) (in the continuous setting), this allows for arbitrages in the market. However, the situation in the case of jumps is not clear. Moreover, it is not clear what happens if there is a delay in the system. In this paper we consider a jump diffusion market model with a singular drift term modelled as the local time of a given process, and with a delay theta > 0 in the information flow available for the trader. We allow the stock price dynamics to depend on both a continuous process (Brownian motion) and a jump process (Poisson random measure). We believe that jumps and delays are essential in order to get more realistic financial market models. Using white noise calculus we compute explicitly the optimal consumption rate and portfolio in this case and we show that the maximal value is finite as long as theta > 0. This implies that there is no arbitrage in the market in that case. However, when theta goes to 0, the value goes to infinity. This is in agreement with the above result that is an arbitrage when there is no delay. Our model is also relevant for high frequency trading issues. This is because high frequency trading often leads to intensive trading taking place on close to infinitesimal lengths of time, which in the limit corresponds to trading on time sets of measure 0. This may in turn lead to a singular drift in the pricing dynamics. See e.g. Lachapelle et al. (Math Finan Econom 10(3):223–262, 2016) and the references therein.

A multi-criteria evolutionary-based algorithm as a regional scale decision support system to optimize nitrogen consumption rate; A case study in North China plain

Nitrogen mismanagement is a serious concern worldwide since farmers usually overuse chemical fertilizers to increase yield, and consequently their income. The oversupply of chemical fertilizers, particularly nitrogen-based fertilizers, has brought about serious environmental problems, among others, deterioration of water quality, global warming impacts, soil acidification, and water eutrophication. In the present study, a decision support system coupled with an evolutionary algorithm was developed to optimize nitrogen consumption rate in a Wheat-Maize rotation system in the North China Plain. The developed model integrated eight indicators, i.e., yield, nitrogen uptake by grain and whole plant, economic, enviro-economic, nitrogen use efficiency, nitrogen balance, and single score (i.e., an aggregated and normalized environmental indicator), to propose the optimal consumption rates. The indicators, used in this model, were measured and/or calculated from a three-year field experiment conducted in six different monitoring sites in four Provinces. Such approach helped introduce the spatially explicit optimal nitrogen application rates for different regions. Having integrated enviro-economic indices, the decision support system returned regional optimum consumption rates which would maximize profit and minimize environmental pollution. Moreover, the decision support system was also supplemented with two sensitivity analysis models, from one hand, to investigate the consequences of changes in decision criteria, and from the other hand, return a range of optimal consumption rate for each specific region. The results achieved showed that the proposed approach succeeded in finding the best nitrogen practices for each specific region and also returning a safe range for nitrogen application in order to guarantee a high-profit and an environmental friendly agricultural production.

Cost-Aware Renewable Energy Management With Application in Cellular Networks

In this paper, we propose a cost minimization strategy for facilities with shared access to a renewable energy farm. We assume space-time varying electricity prices, and model the facilities as non-deferrable time-varying loads. A practical application of such an arrangement can be found in cellular networks, where operators can deploy a centralized energy farm to (partially) power their base stations in a given geographical area. Unlike existing works, we take into account the non-linear behavior of the battery at the energy farm, and obtain closed-form results by solving the corresponding optimization problem in continuous time . We also derive a closed-form expression which estimates the maximum cost saving in terms of the total energy harvested across the entire planning horizon. The results presented in this paper can be used to devise and benchmark low-complexity online strategies, and to understand the relationship between the maximum cost saving, the optimal consumption rate of renewable energy, and system parameters such as battery efficiency and nominal output power.

Retirement spending and biological age

We solve a lifecycle model in which the consumer’s chronological age does not move in lockstep with calendar time. Instead, biological age increases at a stochastic non-linear rate in time like a broken clock that might occasionally move backwards. In other words, biological age could actually decline. Our paper is inspired by the growing body of medical literature that has identified biomarkers which indicate how people age at different rates. This offers better estimates of expected remaining lifetime and future mortality rates. It isn’t farfetched to argue that in the not-too-distant future personal age will be more closely associated with biological vs. calendar age. Thus, after introducing our stochastic mortality model we derive optimal consumption rates in a classic (Yaari, 1965) framework adjusted to our proper clock time. In addition to the normative implications of having access to biological age, our positive objective is to partially explain the cross-sectional heterogeneity in retirement spending rates at any given chronological age. In sum, we argue that neither biological nor chronological age alone is a sufficient statistic for making economic decisions. Rather, both ages are required to behave rationally.