Maximum Potential Value Research Articles

Exploring Controls on Tropical Cyclone Count through the Geography of Environmental Favorability

AbstractGlobally, on the order of 100 tropical cyclones (TCs) occur annually, yet the processes that control this number remain unknown. Here we test a simple hypothesis that this number is limited by the geography of thermodynamic environments favorable for TC formation and maintenance. First, climatologies of TC potential intensity and environmental ventilation are created from reanalyses and are used in conjunction with historical TC data to define the spatiotemporal geography of favorable environments. Based on a range of predefined separation distances, the geographic domain of environmental favorability is populated with randomly placed TCs assuming a fixed minimum separation distance to achieve a maximum daily packing density of storms. Inclusion of a fixed storm duration yields an annual “maximum potential genesis” (MPG) rate, which is found to be an order of magnitude larger than the observed rate on Earth. The mean daily packing density captures the seasonal cycle reasonably well for both the Northern and Southern Hemispheres, though it substantially overestimates TC counts outside of each hemisphere’s active seasons. Interannual variability in MPG is relatively small and is poorly correlated with annual storm count globally and across basins, though modest positive correlations are found in the North Atlantic and east Pacific basins. Overall, the spatiotemporal distribution of favorable environmental conditions appears to strongly modulate the seasonal cycle of TCs, which certainly strongly influences the TC climatology, though it does not explicitly constrain the global annual TC count. Our methodology provides the first estimate of an upper bound for annual TC frequency and outlines a framework for assessing how local and large-scale factors may act to limit global TC count below the maximum potential values found here.

Synthesis of copper oxide quantum dots: effect of surface modifiers

Copper oxide quantum dots were synthesized via precipitation process. Different surface modifiers (SMs) such as polyvinylpyrrolidone (PVP), Polyethylene glycol sorbitan monooleate (Tween 80) and Cetyltrimethylammonium bromide (CTAB) were used for modification of the size and shape of CuO nanoparticles. The effects of some parameters such as the type of surface modifiers on the band gap, structure and microstructure of samples were investigated. All samples showed quantum confinement behaviors such as band gap widening, the size less than the Bohr radius and the blue-shift of adsorption edge. The change of morphology from rod-like in the presence of Tween-80 to spindle shapes in CTAB one confirmed the strategic role of covering the surface of CuO particles by SMs. Moreover, CuO quantum dots with mean crystallite size of 2.3 nm and band gap of 2–2.5 eV were synthesized successfully. Furthermore, high degree of dispersion belonged to CuO nanoparticle synthesized by CTAB SM due to the maximum zeta potential value (28.1 mV at pH = 7.5).

Study on the effect of mesh ratio to the potential distribution of RC cathodic protection using BEM

Researchers and engineers have used cathodic protection (CP) to prevent corrosion in reinforced concrete (RC). Boundary element method (BEM) is a promising numerical technique to evaluate the effectiveness of CP on RC structures. However, some parameters that might affect the system or the potential distribution, such as mesh ratio, still need to be studied further. This paper aims to study the effect of mesh ratio on the potential distribution of RC installed CP using BEM. Simple 3D beam model of RC was used for the case study. The mesh for the model was triangular element and six variations of the mesh ratio were selected for the study. The mesh ratio obtained from the comparison between the size of the concrete element and the anode or cathode element. Simulation results show that the distribution of potential for all mesh ratios is within the protection criteria (⩽ −850 mV vs Cu/CuSO4). However, the difference between maximum and minimum potential value becomes smaller when the mesh ratio increased. Hence, it shows that the mesh ratio has an effect on the distribution of potential of RC installed CP. However, it is still tolerable since the potential within protection criteria.

Preparation of Ginger Oil in Water Nanoemulsion Using Phase Inversion Composition Technique: Effects of Stirring and Water Addition Rates on their Physico-Chemical Properties and Stability

Abstract Ginger oil in water (O/W) nanoemulsions, were produced using phase inversion composition method and Tween 80, as emulsifier. Effects of processing parameters namely, stirring rate (100 to1000 rpm) and water addition rate (1–10 mL/min) were evaluated on the physico-chemical, morphological, antioxidant and antimicrobial properties of the prepared O/W nanoemulsions using response surface methodology (RSM). Results indicated that well dispersed and spherical ginger nanodroplets were formed in the nanoemulsions with minimum particle size (8.80 nm) and polydispersity index (PDI, 0.285) and maximum zeta potential value (−9.15 mV), using stirring rate and water addition rate of 736 rpm and 8.18 mL/min, respectively. Insignificant differences between predicted and experimental values of the response variables, indicated suitability of fitted models using RSM. Mean particle size of the prepared nanoemulsion using optimum conditions were changed from 8.81 ± 1 to 9.80 ± 1 nm, during 4 weeks of storage, which revealed high stability of the resulted ginger O/W nanoemulsion. High antioxidant activity (55.4%), bactericidal (against Streptococcus mutans) and fungicidal (against Aspergillus niger) activities of the prepared nanoemulsion could be related to the presence of gingerols and shogaols, a group of phenolic alkanones, in the ginger oil, which those were detected by gas chromatography method.

Monetary Value of a District’s Flexibility on the Spot- and Reserve Electricity Markets

In the future, advanced multi-energy systems are expected to handle an increasing share of fluctuating renewable energy generation through the management of multiple advanced energy conversion and storage technologies operating across different energy carriers. The market diffusion of such concepts of Local Energy Management—the management of energy supply, demand, and storage within a given geographical area—is expected to provoke a fundamental reorganization of the power generation sector. This work contributes to this topic by estimating the maximum potential economic value attained from using the flexibility of a district to take advantage of operating within multiple electricity markets at the same time. The study is based on the measured demand and production data of a newly built suburban residential district located in Central Switzerland. The actual configuration of the district and the resulting flexibility, as well as an extension with a battery storage system, is used to estimate the economic value of the flexibility. Then, an optimization algorithm manages flexible demand, production, and storage capacities in order to alternatively maximize the revenues/cost savings, self-sufficiency, or share of renewable resources of the district’s energy supply. In this vein, the impact of the way the system operates in the markets regarding the degradation of the battery is assessed and its pay-back-time is estimated. The analysis revealed a considerable profit potential associated with the district thermal and electricity storage flexibility, in particular, when operating on both the spot and reserve electricity markets. Firstly, it was shown that overall energy costs can be minimized through an optimal management of energy conversion and storage systems. Secondly, complementing the infrastructure with batteries and trading flexibility on the spot market would decrease costs by about 43%, while an additional 20% cost decrease could be captured by including trading on the reserve market. Thirdly, it has been shown that operation on the spot- and reserve market does not seem to degrade the battery more than solely operation on the spot market. However, when operating on the spot- and reserve markets, battery amortization would still take about 10 years.

An overview of claw disorders at slaughter in finishing beef cattle reared in intensive indoor systems through a cross-sectional study

This cross-sectional study aimed to assess in post-mortem the prevalence of specific claw disorders and their location on the sole in hind feet of finishing beef cattle reared indoors under intensive production systems. Evaluation was made on animals that were introduced in the ordinary slaughterhouse planning, presumably with no signs of impaired locomotion or severe lameness. A total of 4292 hind feet (right and left) belonging to 153 batches were collected (average feet/batch 28.1 ± 5.62 (SD)) in 3 abattoirs in Northern Italy at 3 time points (April-June and September-October 2016; February–March 2017). One veterinarian performed the claw trimming first and then scored the presence of specific claw disorders and their position on the sole considering 7 zones (in the digital and interdigital areas). All claw disorders in a specific zone were recorded as binary (presence/absence). Infectious (ILS), non-infectious (NILS), and global (GLS) scores were calculated considering both the type of claw disorder detected and the number of zones affected. Non-infectious disorders were the most common diagnoses among batches, mainly on the lateral claws and in the heel-sole junction area. In particular, white line abscesses and ulcers (sole and toe ulcers) were also found as two of the most debilitating and painful lesions with a non-negligible frequency. Infectious diseases, when occurring in a batch, spread to almost all feet. As expected, GLS distribution on the total feet inspected showed a non-harmful condition, given that the worst scores from 3 to 13 were assigned to a restricted sample of feet (15%) and were far from the maximum potential value of 50. However, the GLS of all batches monitored revealed 10 critical batches having no healthy feet or more than 50% of feet graded with the worst scores.Since right and left feet of the same animal showed similar clinical diagnoses, a more efficient claw health evaluation system should consider only one foot.Although all cattle inspected were supposed to have no evident locomotory problems before slaughter, the detection of several foot disorders and the considerable distribution in some batches might suggest poor conditions on farms affecting finishing beef cattle health, behaviour, and welfare. It is therefore advisable that possible predisposing factors of specific claw disorders on the farms of origin be investigated more deeply.

How do the micropores of carbon xerogels influence their electrochemical behavior as anodes for lithium-ion batteries?

Abstract This work aims at shedding light on how the microporous texture of porous carbons influences their electrochemical behavior when used as anodes for Li-ion batteries. To this aim, a synthetic hard carbon (carbon xerogel, CX), prepared from a resorcinol-formaldehyde precursor gel, underwent several post-synthesis treatments in order to modulate its micropore to total pore volume ratio. The micropore volume was either expanded by physical activation or decreased using chemical vapor deposition (CVD) of a carbon layer. Several variables other than the micropore texture of the obtained carbons, which could influence their behavior as anode active materials for Li-ion batteries, such as the particle size or the electrode characteristics, were carefully controlled. The thickness of electrode coatings and the pore texture of the active material-binder composite were analyzed. It was shown that CX-binder composites resulting from water-based slurries preserve the microporosity of the starting materials. Detailed electrochemical characterization of the electrodes prepared with carbon xerogels displaying various defined micropore textures was performed. A clear linear dependency could be evidenced between the Li+ insertion and de-insertion in half-cell configuration with the increase of the volume of supermicropores (0.7–2 nm), demonstrating the effect of micropore enlargement by activation on the storage capacity, provided the maximum charge potential value is set at 3.0 V vs. Li+/Li.

Effect of Geopolymer Coating on Mild Steel

This paper presents the results of a study on the effect of geopolymer coating on mild steel. Geopolymer is synthesis of a fly ash and alkaline activators which are sodium hydroxide solution (NaOH) and sodium silicate solution (Na2SiO3). Fly ash is one of residue produced during the combustion of coal in coal power plant. In this study, fly ash class F based geopolymer was used as a source material. The alkaline activators then were mixed with fly ash to produce the geopolymer paste which acts as a coating material. The mixture was placed in molds and reinforcement bar were embedded in geopolymer paste. After that, the corrosion behavior of reinforcement bars for all samples were observed by using Open Circuit Potential (OCP) testing. Referring the pourbaix diagram regarding OCP testing, samples are in passivity region. Besides that, mild steel also were coated with geopolymer paste for adhesion test. Elcometer 108 was used for adhesion strength test. Morphology analysis also been used to determine the microstructure of fly ash and geopolymer paste. Phase analysis was used for the analysis phase between fly ash, geopolymer paste and mild steel coated with geopolymer paste. From OCP test, pourbaix diagram shows that samples is placed in the passivity region, iron (III) oxide (Fe2O3) which is in stable phase and iron (II, III) oxide same results as in phase analysis. The minimum potential value for OCP is 0.015 V and the maximum potential value is 0.133 V. For adhesion strength, day 14 got the highest results compared day 7 and day 3 which the results are 2.0 Mpa, 1.9 Mpa and 1.5 Mpa respectively. It is because from day 3 until day 14, the structure of geopolymer paste becomes more compact, denser and better crystallization as shown in morphological analysis.

Accelerated fuel cell tests of anodic Pt/Ru catalyst via identical location TEM: New aspects of degradation behavior

In the present work the stability, chemical composition and structure of a Pt/Ru catalyst alloy with a nominal ratio of 1/1 is investigated. The same catalyst particles are analyzed before and after potential cycling experiments using identical location transmission electron microscopy. The experiments were performed at room temperature at [0–1.0] VRHE and [0–1.2] VRHE to simulate conditions occurring during ramping up of fuel cells. With decreasing maximum potential value a higher stability is found. Dissolution and dealloying are identified to be the main degradation mechanisms during potential cycling with Ru being dissolved preferably. Also agglomeration and Ostwald ripening are taking place, the frequency decreasing the longer the experiment is performed. Advanced in-depth analysis of potential-dependent reshaping mechanisms are performed by calculating the three-dimensional volume of single particles both in the as-prepared state and after potential cycling experiments using electron tomography data. Evaluation of the volume-specific change of the accessible surface area of the catalyst helps to understand fuel cell performance deterioration.

Process Optimization and Characterization of YSZ Thin Film Electrolyte on Anode Substrate Prepared by Electrophoretic Deposition Technique

Thin film electrolyte made of 8-mol% yttria stabilized zirconia (8YSZ) was fabricated on porous NiO-8YSZ anode substrates using electrophoretic deposition (EPD). The porous NiO-8YSZ anode substrates were prepared by powder injection molding technique. The electrolyte suspensions containing 8YSZ nanoparticles and polyethylene glycol (PEG) as a dispersant (1-19 wt%) were formed in ethanol. The maximum zeta potential value was obtained from the 8YSZ suspension with 5 wt% PEG considered as an optimal content of PEG dispersant. The electrophoretic deposition of 8YSZ film was performed on the porous anode substrate using a constant voltage of 30 V for 150 sec prior to co-sintering at different temperatures in order to obtain dense 8YSZ electrolyte film on the porous anode substrate. Co-sintering at 1250°C for 1 h resulted in a formation of a dense 8YSZ thin-film electrolyte with a thickness of 6.35 mm. An open circuit voltage at 800°C of a single cell having 8YSZ thin-film electrolyte on porous NiO-8YSZ anode substrate was 1.09 V, indicating a gas-tightness of 8YSZ thin-film electrolyte fabricated by using EPD.

Uso antropocéntrico del guaje Leucaena esculenta (Moc. y Sessé Ex. DC.) Benth, en dos comunidades de la mixteca baja oaxaqueña.

The aim of this study was to quantify by means of canonical discriminant analysis (CDA) the use of guaje in food and traditional medicine, as well as the level of knowledge of this plant in the communities of Santiago Huajolotitlan and S. Cacaloxtepec in the mixteca baja region of the state of Oaxaca, Mexico. Stratified random sampling was performed and a questionnaire was applied in each community. Subsequently the maximum potential knowledge value of each respondent (MP) was calculated, and data analysis was performed using canonical discriminant analysis (CDA). The MP was (0.87) for the community of S. Huajolotitlan and (0.81) for S. Cacaloxtepec, which showed that the respondents have knowledge about the biology and medicinal use of guaje. The CDA showed significant difference (α = 0.05) in how to prepare guaje in both communities in Huajolotitlan, 55.3% prepare guaje in sauce, 8.3% in guaximole. With regard to diseases related to parasites, the variation percentage was 57%, whereas it was 21% for stomach pain. In Cacaloxtepec, 30% of respondents consume guaje in sauce. The variation percentage for medicinal use was 35% for deworming and 16% for making handicrafts. It is concluded that the main use of guaje in both communities is as food, the seeds being the main edible structure, and as a deworming agent, for which the bark is used.

Effects of flexoelectricity and surface elasticity on piezoelectric potential in a bent ZnO nanowire

In this work, a rapid model is established to study the effects of flexoelectricity and surface elasticity on the piezoelectric potential of a bent ZnO nanowire. Based on the piezoelectric theory and core-surface model, the distribution of piezoelectric potential of the ZnO nanowire is investigated. The analytical solution shows that the flexoelectricity and surface elasticity both significantly influence the piezoelectric potential. However, the effect of flexoelectricity is longitudinal dependent, which vanishes on the top side of nanowire, but only left surface elasticity effect on the potential. Simulation results show that the maximum value of potential on the top side of nanowire is about ± 220.5mV, of which result is lower compared to other theoretical models, but it should be more reasonable.

A figure of merit for overall performance and value of AFDD tools

A figure of merit, V, to characterize the value of an AFDD maintenance tool is presented. The AFDD tool is fed data representing air-conditioners operating with and without faults across a range of conditions. The calculation of V considers the probability of each scenario occurring, the tool's response, and the resulting implications. These results are summed to give a typical average value for deploying the AFDD tool, as compared to maintenance being performed without AFDD. Case studies illustrate the calculation of V. Six AFDD tools and two idealized tools are evaluated. Five of the six real tools give negative V, meaning that their use causes more harm than good. The sixth shows approximately $10 benefit per nominal ton of air-conditioner capacity per typical maintenance visit. This represents about half of the maximum potential value. These results demonstrate the importance of measuring AFDD performance and the potential monetary benefits of AFDD.

Advection and dispersion heat transport mechanisms in the quantification of shallow geothermal resources and associated environmental impacts

Borehole Heat Exchangers (BHEs) are increasingly being used to exploit shallow geothermal energy. This paper presents a new methodology to provide a response to the need for a regional quantification of the geothermal potential that can be extracted by BHEs and the associated environmental impacts. A set of analytical solutions facilitates accurate calculation of the heat exchange of BHEs with the ground and its environmental impacts. For the first time, advection and dispersion heat transport mechanisms and the temporal evolution from the start of operation of the BHE are taken into account in the regional estimation of shallow geothermal resources.This methodology is integrated in a GIS environment, which facilitates the management of input and output data at a regional scale. An example of the methodology's application is presented for Barcelona, in Spain. As a result of the application, it is possible to show the strengths and improvements of this methodology in the development of potential maps of low temperature geothermal energy as well as maps of environmental impacts. The minimum and maximum energy potential values for the study site are 50 and 1800W/m2 for a drilled depth of 100m, proportionally to Darcy velocity. Regarding to thermal impacts, the higher the groundwater velocity and the energy potential, the higher the size of the thermal plume after 6months of exploitation, whose length ranges from 10 to 27m long. A sensitivity analysis was carried out in the calculation of heat exchange rate and its impacts for different scenarios and for a wide range of Darcy velocities. The results of this analysis lead to the conclusion that the consideration of dispersion effects and temporal evolution of the exploitation prevent significant differences up to a factor 2.5 in the heat exchange rate accuracy and up to several orders of magnitude in the impacts generated.

Evaluation and comparison of the ammonia adsorption capacity of titanosilicates ETS-4 and ETS-10 and aluminotitanosilicates ETAS-4 and ETAS-10

Due to the well-known adsorption properties of titanosilicates (ETS-4 and ETS-10) and aluminotitanosilicates (ETAS-4 and ETAS-10), it was considered particularly interesting to investigate their efficiency in adsorbing ammonia from a gaseous phase. Prior to testing their adsorption capacity, materials thus synthesized have been analyzed by appropriate characterization techniques. Afterward, the adsorption capacity of microporous materials toward ammonia has been evaluated by measuring the corresponding adsorption isotherms through batch experiments. Experimental measurements were best fitted by a linear constant relationship. From the experimental results, high adsorption capacity values were found for all microporous materials in correspondence of high gaseous ammonia concentration values. In particular, ETAS-10 attained the maximum value of adsorption potential, equal to 7.647 mg of NH3 per g of material. This was likely due to the presence of the acid site linked to the Al atom in its structure with respect to the ETS structure. In addition to that the greater pore size characterizing the phase 10 compared to phase 4 might have entailed a more selective sorption of ammonia molecule. Overall, both titanosilicates and aluminotitanosilicates showed a great adsorption potential toward ammonia. However, materials achieved their maximum capacity at high pollutant loading.

Biosorption of nickel by Lysinibacillus sp. BA2 native to bauxite mine

The current scenario of environmental pollution urges the need for an effective solution for toxic heavy metal removal from industrial wastewater. Bioremediation is the most cost effective process employed by the use of microbes especially bacteria resistant to toxic metals. In this study, Lysinibacillus sp. BA2, a nickel tolerant strain isolated from bauxite mine was used for the biosorption of Ni(II). Lysinibacillus sp. BA2 biomass had isoelectric point (pI) of 3.3. The maximum negative zeta potential value (−39.45) was obtained at pH 6.0 which was highly favourable for Ni(II) biosorption. 238.04mg of Ni(II) adsorbed on one gram of dead biomass and 196.32mg adsorbed on one gram of live biomass. The adsorption of Ni(II) on biomass increased with time and attained saturation after 180min with rapid biosorption in initial 30min. The Langmuir and Freundlich isotherms could fit well for biosorption of Ni(II) by dead biomass while Langmuir isotherm provided a better fit for live biomass based on correlation coefficient values. The kinetic studies of Ni(II) removal, using dead and live biomass was well explained by second-order kinetic model. Ni(II) adsorption on live biomass was confirmed by SEM-EDX where cell aggregation and increasing irregularity of cell morphology was observed even though cells were in non-growing state. The FTIR analysis of biomass revealed the presence of carboxyl, hydroxyl and amino groups, which seem responsible for biosorption of Ni(II). The beads made using dead biomass of Lysinibacillus sp. BA2 could efficiently remove Ni(II) from effluent solutions. These microbial cells can substitute expensive methods for treating nickel contaminated industrial wastewaters.

HASTA

In this paper, a novel clustering algorithm, HASTA (HierArchical-grid cluStering based on daTA field), is proposed to model the dataset as a data field by assigning all the data objects into qusantized grids. Clustering centers of HASTA are defined to locate where the maximum value of local potential is. Edges of cluster in HASTA are identified by analyzing the first-order partial derivative of potential value, thus the full size of arbitrary shaped clusters can be detected. The experimented case demonstrates that HASTA performs effectively upon different datasets and can find out clusters of arbitrary shapes in noisy circumstance. Besides those, HASTA does not force users to preset the exact amount of clusters inside dataset. Furthermore, HASTA is insensitive to the order of data input. The time complexity of HASTA achieves O(n). Those advantages will potentially benefit the mining of big data.

Vapor nucleation on a wettable nanoparticle carrying a non-central discrete electric charge

We have studied thermodynamics of vapor nucleation on a spherical wettable dielectric nanoparticle carrying a discrete electric charge located at a certain distance from the particle center. New general equations for the chemical potential of a condensate molecule in the droplet around the particle, the work of the droplet formation and the droplet shape as functions of the effective radius of condensate film, and the value of an electric charge and its location with respect to the particle center have been derived analytically. These equations take into account both the effects of the non-central electric field and the disjoining pressure in the thin liquid film forming the droplet. Under the assumption of small distortion of the droplet shape in the axisymmetric electric field of non-central discrete charge from the spherical one, these equations have been simultaneously solved analytically. The obtained explicit formulas for the condensate chemical potential, the work of droplet formation, and the droplet shape have been numerically investigated for the case of the charge adsorbed below and above the surface of the particle. It has been shown that the effect of the electric field of non-central charge reveals itself in decreasing the maximum value of the condensate chemical potential in the droplet and shifting it away from the particle surface. As a result, the threshold value of the vapor supersaturation for barrierless nucleation and the activation barrier for barrier nucleation on the charged nanosized nuclei diminish in comparison with nucleation on nuclei with central charge. The effect is larger for smaller nuclei. It decreases with increase in the dielectric constant of the nuclei in the case of charge location below the particle surface.

Influence of pH on the property of apatite-type lanthanum silicates prepared by sol-gel process

The apatite-type lanthanum silicates with formula La9.33Si6O26 are prepared by sol-gel process. The homogeneity of the sol affected by pH value of the solution is investigated. The viscosity of the sols slightly increases first and then increases abruptly because the predominant reaction mechanism changes from hydrolysis reaction to condensation reaction. In addition, the onset time of the increase for the viscosity shortens from pH 1 to pH 4. The gelation time decreases with increasing pH of the solution. Therefore, the pH of the sols should be less than 4 to form gel. The sol with initial pH 2 shows maximum value of zeta potential and maximum stability. For the sample with initial pH 2, pure apatite-type lanthanum silicates La9.33Si6O26 have been successfully prepared after the dried gel is calcined at 1 000 °C. In addition, this sample sintered at 1 550 °C exhibits the highest ionic conductivity. The activation energies are all less than 0.90 eV.

Exploratory analysis of a wide spectrum of biochemical markers in a large cohort of individuals with symptoms of very early knee and hip osteoarthritis: data from check

Exploratory analysis of a wide spectrum of biochemical markers in a large cohort of individuals with symptoms of very early knee and hip osteoarthritis: data from check