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A rapid rise in the development of portable electronic devices and telecommunication technologies has led to an ever-growing demand for high safety, large energy density, and cost-effective systems for storing energy. Rechargeable all-solid-state lithium-ion batteries are extremely productive without compromising performance. In this study, garnet-type Li7La3Zr2O12 (LLZO) filler was prepared employing the sol–gel method. That follows, the high-performance poly(ethylene oxide)/lithium perborate (LiBO3)/LLZO composite solid polymer electrolyte was fabricated using a simple solution-casting technique. The morphology and composition of the prepared CSPE (composite solid polymer electrolyte) (PEO-LiBO3-LLZO) were investigated using X-ray diffraction and scanning electron microscopy in addition to other physicochemical characterization techniques. The composite solid polymer electrolyte exhibits a maximum ionic conductivity of 2.8 × 10−4 S cm−1 with LLZO filler and a wide electrochemical window of 4.5 V vs. Li+/Li. The prepared electrolyte reveals good electrochemical efficiencies with elevated discharge capacity of 73.4 mAhg−1 and excellent coulombic efficiency of 99% since 100 cycles. Based on these results, the prepared composite solid polymer electrolyte furnishes an auspicious methodology for the advancement of high-performing rechargeable all-solid-state lithium-ion batteries. [ABSTRACT FROM AUTHOR]

H-weir is a combination of a rectangular gate and weir. Side weirs are applied to discharge flow and regulate the flow height. The present study presents the modeling of the H-side weirs using experiments and optimization based on SVM in a straight channel under free and subcritical flow conditions. The geometrical and flow parameters affecting the discharge capacity were determined based on dimensional analysis. The findings show that the weir flow is not in contact with the flow below the gate with increased vertical distance between the weir crest and gate top (d) and the upstream Froude number (F1). It was found that the discharge capacity of the H-side weir is 1.3–4.0 times higher than conventional side weirs and 1.6–9.0 times higher than side gates under the same conditions. Moreover, a discharge equation is derived from a/y1, h/b, b/B, F1 and d/a with an absolute percentage error of about 5.84%. The most successful model for predicting the discharge of the H-side weir was VMD-LSSVM. In addition, it was concluded that the established LSSVM, PSO-LSSVM and PSO-VMD-LSSVM models produced very satisfactory predictions. [ABSTRACT FROM AUTHOR]

Current AB5-type hydrogen storage alloys employed in nickel-metal hydride (NiMH) batteries exhibit exceptional low-temperature discharge performance but suffer from limited cycle life and insufficient high-temperature stability. To overcome these challenges, we introduce a hydrothermal synthesized LaF3 coating layer on the surface of the AB5 anode material. This LaF3 coating layer adds a protective barrier for the active material, significantly improving the battery's cycle life and high-temperature stability. Our findings indicate that (1) the LaF3 coated anode demonstrates an extended cycle life with increased specific capacity and a capacity retention of 88% after 40 cycles of abusive overcharging and rapid discharging at room temperature. (2) The synthesized anode exhibits a 97% recovery of its specific capacity of 292.7 mAh/g following 144 h of high-temperature storage. (3) The low-temperature discharge capacity of the synthesized anode remains on par with the pristine AB5 alloy at 230.4 mAh/g in a −40 °C environment. This research presents a significant advancement in hydrogen storage alloy coatings and offers valuable insights for designing electrodes in NiMH batteries. [ABSTRACT FROM AUTHOR]

Renewable and sustainable energies are vital for the near future. Hydrogen, as a clean energy carrier, is a potential candidate for supplying energy in the foreseeable future. Nowadays, hydrogen storage technology has become a significant issue in the energy sector. In this study, ZnCo 2 O 4 /ZnO and MgCo 2 O 4 /MgO nanocomposites have been synthesized using the sol-gel method with stearic acid as a complexing agent. Different analyses were studied to examine the crystal structure, morphology, and physical properties of the as-prepared samples, including X-ray diffraction (XRD), Fourier transforms infrared (FT-IR), field emission scanning electron microscopy (FESEM), diffuse reflectance spectroscopy (DRS), and vibrating sample magnetometer (VSM). Various methods have been utilized for hydrogen storage technology. In a pioneering approach, the electrochemical hydrogen storage of samples was compared by the chronopotentiometry technique in KOH (4 M) electrolyte solution. The results reveal that ZnCo 2 O 4 /ZnO and MgCo 2 O 4 /MgO nanocomposites exhibit excellent discharge capacities of 4240 and 3529 mAh/g, respectively, after 11 cycles. [Display omitted] • Zinc and magnesium cobaltite nanocomposites were synthesized. • As a novel approach, the hydrogen storage performance of the as-prepared samples was evaluated by the chronopotentiometry (CP) technique. • The discharge capacity of the nanocomposites was recorded as 4240 and 3529 mAhg−1, respectively. [ABSTRACT FROM AUTHOR]

A compound channel's discharge capacity and boundary shear force can be predicted as a sum of the discharge capacity of different sub-regions once the apparent shear stress of the dividing line is reasonably quantified. The apparent shear stress was usually expressed as a coefficient multiplied by the difference between two squared velocities of two adjacent regions. This study investigated the range of the coefficient values and their influencing factors. Firstly, the optimal values of the coefficient were obtained based on experimental data. Then, comparisons between the optimal values and several parameters used in quantifying the apparent shear stress were conducted. The results show that the coefficient is mainly related to a morphological parameter of the floodplain and the ratio of resistance coefficients between the floodplain and the main channel. An empirical formula to calculate the coefficient was developed and introduced to calculate the flow discharge and boundary shear stress. Experimental data, including 142 sets of test data of symmetric-floodplain cases and 104 sets of one-floodplain cases, have been used to examine the prediction accuracy of discharges and boundary shear stress. For all these tests, the ranges of water depth of the main channel and the total width of the compound cross-section are about 0.05~0.30 m and 0.3~10 m, respectively; the Q range and the range of Froude numbers of the main channel flow are about 0.0033~1.11 m3/s and 0.3~2.3, respectively. Comparison with other methods and experimental data from both rigid and erodible compound channels indicated that the proposed method not only provided acceptable accuracy for the computation of discharge capacity and boundary shear stress of compound channels in labs but also gave insights for calculating discharge capacity in natural compound channels. [ABSTRACT FROM AUTHOR]

Over the years, alloys have been the predominant choice of electrode material for electrochemical hydrogen storage. However, they encounter challenges emerging from their complex synthesis process and intricate structure, leading to low discharge capacity. Hierarchical Ni 3 S 2 nanorods-embedded flower-shaped NiMn-layered double hydroxide (LDH) microspheres (∼10 μm) are, thus, synthesized via a facile one-pot binder-free hydrothermal process and examined for their electrochemical hydrogen storage behavior. The Ni 3 S 2 /Ni 2 Mn 1 -LDH composite showcased superior reversibility and a maximum storage capacity of ∼860 mAh/g at 1000 mA/g current density under ambient temperature and pressure conditions. It exhibited a Coulombic efficiency of ∼86% and a capacity retention rate of ∼98% even after 100 charge-discharge cycles in 3 M KOH electrolyte. The enhanced electrochemical performance is attributed to the layered morphology and synergistic behavior demonstrated by the Ni 3 S 2 nanorods on the LDH layers. To this end, the material emerges as a promising and efficient candidate to be utilized in energy storage systems. [Display omitted] • Ni 3 S 2 /Ni 2 Mn 1 -LDH developed as an efficient material for electrochemical H 2 storage. • High storage capacity of ∼860 mAh/g attributed to Ni 3 S 2 -embedded LDH microspheres. • High cyclic stability over 100 cycles with a Coulombic efficiency of ∼86%. • Storage mechanism depicting synergistic effects of spillover, redox, and H-bonding. [ABSTRACT FROM AUTHOR]

New perspective organic electrode materials based on triquinoyl derivatives for organometallic batteries with increased discharge capacities of more than 500 mA h/g are described. New electrolytes compatible with organic electrodes have been developed. It has been established that the incomplete desolvation of lithium ions during their interaction with organic electrode materials is the reason for the decrease in the electrochemical capacity in electrolytes based on carbonate solvents. The mechanism of interaction of the solvated lithium cation with organic electrode materials was studied using the example of a polymeric condensation product of triquinoyl with 1,2,4,5-tetraaminobenzene (PTTA). For comparison, the solvate shells of the lithium cation from ethylene carbonate/dimethyl carbonate (EC/DMC) and tetraglyme were chosen. Quantum-chemical modeling of the interaction of lithium cation solvate complexes with solvent molecules was compared with electrochemical data on the study of the interfaces of PTTA with liquid electrolytes: 1 M LiPF6 solution in EC/DMC (1 : 1) and 1 M LiPF6 solution in tetraglyme. Based on theoretical and experimental studies, it was shown that the process of lithium cation desolvation in an electrolyte based on tetraglyme makes it possible to obtain a capacity close to the theoretical one (up to 546 mA h/g), while for the EC/DMC electrolyte it is only 125 mA h/g. This decrease is due to the fact that the lithium cation adds to the functional groups of the organic material with two dimethyl carbonate molecules, and the adsorption of the PF6– anion occurs. And in the case of tetraglyme, the process of lithiation–delithiation of organic material occurs without the participation of the solvate shell. This fundamental result was obtained for the first time and applies to all organic electrode materials tested in carbonate solvents. [ABSTRACT FROM AUTHOR]

Potassium–oxygen batteries (KOBs) are a promising energy storage technology with high theoretical energy density, low overpotential and a long cycle life. The cathode microstructure plays a significant role in the electrochemical performance of KOB. In this article, hierarchical porosity was introduced to commercially available carbon paper cathodes by thermal pretreatment in air at different pretreatment times. This pretreatment modifies the properties, such as surface area, defects, oxygen functional groups, etc. The discharge performance was determined at three different current densities, i.e., 0.1 mA/cm2, 0.5 mA/cm2, and 1.0 mA/cm2. It has been found that an increase in specific surface area with the introduction of micropores and mesopores is beneficial for the improvement in the discharge capacity by enabling homogeneous discharge product, KO2 distribution and high degrees of pore filling over the volume of the cathode. A reduction in the discharge overpotentials was observed, which is attributed to the introduction of oxygenic functional groups and defects. Samples treated for the longest pretreatment time of 24 h showed the highest discharge capacity of 5 mAh/cm2 and lowest discharge overpotential of 0.03 V. [ABSTRACT FROM AUTHOR]

Promising metal hydride electrode performance of LaNi4.5Co0.4Al0.1, prepared by induction melting and next hydrogen-induced decrepitation, was proven in the present study. Both the composition and microstructure of the electrode material were found to be responsible for its reliable hydrogen capacity and cycle stability. After prolonged exposure to air, the alloys retain their high hydrogen sorption characteristics, revealing only 10% capacity reduction. The gas phase hydriding of the alloys confirms the hydrogen capacity obtained under electrochemical conditions. Furthermore, the influence of C, Co, and Co3O4 additions to the LaNi5-based alloy on the hydrogen electrode performance was also elucidated. The highest capacity of 300 mAh g−1, remaining constant for 20 cycles, was obtained for LaNi4.5Co0.4Al0.1 + 15 mg Co3O4. This material maintains excellent capacity also at high current densities, making it a suitable electrode material in Ni/MH batteries. [ABSTRACT FROM AUTHOR]

The application of LiNi0.5Co0.2Mn0.3O2 is still hindered by its low capacity retention rate and poor high rate performance. The surface coating has proven to be an effective strategy to solve these problems. However, the previous surface coating method will make the synthesis process more complicated. In this work, a simple organic salt decomposition method is developed to prepare LiNi0.5Co0.2Mn0.3O2@Cu cathode material (NCM@Cu). The results of the scanning electron microscope (SEM), X-ray diffractometer (XRD), and energy X-ray spectroscopy (EDS) have confirmed that a uniform copper-coated composite structure has been successfully constructed without changing the crystal structure. Charge and discharge tests show that the irreversible capacity loss of NCM@Cu at 0.2 C is 33.8 mA h g–1, which is lower than NCM. Compared with bare NCM, the composite cathode NCM@Cu has better cycle performance. This improvement is attributed to the coating of the copper element, which increases surface electron transport. [ABSTRACT FROM AUTHOR]

In this article, we present the synthesis of binary CdAl4O7/CdO nanocomposites using green tea extracts and green chemistry methods for high-performance hydrogen storage. The green tea extract contains bioactive compounds (polyphenols) that act as reducing agents, which facilitate the reaction between metal ions and water. By examining the structural and morphological characteristics of the obtained substrates using scanning electron microscopy (SEM), X-ray diffraction (XRD), transmission electron microscopy (TEM), and Fourier transform infrared spectroscopy (FT-IR), it was demonstrated that the nanocomposites were successfully synthesized. We evaluated the electrochemical performance of the synthesized CdAl4O7/CdO nanocomposites using a three-electrode chronopotentiometry system. According to the results, the synthesized nanocomposites are capable of storing 1750 mAh/g of hydrogen at a constant current of 1 Amp. By using green tea extract as a natural structure-directing agent, the CdAl4O7/CdO nanocomposite can be developed more sustainably as high-performance hydrogen storage materials. Ultimately, this work contributes to the advancement of sustainable energy storage through the synthesis of a promising new material. [ABSTRACT FROM AUTHOR]

Li3V2(PO4)3 cathodes for Li-ion batteries (LIBs) were synthesized using a hydrothermal method with the subsequent annealing in an argon atmosphere to achieve optimal properties. The X-ray diffraction analysis confirmed the material's single-phase nature, while the scanning electron microscopy revealed a granular structure, indicating a uniform particle size distribution, beneficial for electrochemical performance. Magnetometry and electron spin resonance studies were conducted to investigate the magnetic properties, confirming the presence of the relatively low concentration and highly uniform distribution of tetravalent vanadium ions (V4+), which indicated low lithium deficiency values in the original structure and a high degree of magnetic homogeneity in the sample, an essential factor for consistent electrochemical behavior. For this pure phase Li3V2(PO4)3 sample, devoid of any impurities such as carbon or salts, extensive electrochemical property testing was performed. These tests resulted in the experimental discovery of a remarkably high lithium diffusion coefficient D = 1.07 × 10−10 cm2/s, indicating excellent ionic conductivity, and demonstrated impressive stability of the material with sustained performance over 1000 charge–discharge cycles. Additionally, relithiated Li3V2(PO4)3 (after multiple electrochemical cycling) samples were investigated using scanning electron microscopy, magnetometry and electron spin resonance methods to determine the extent of degradation. The combination of high lithium diffusion coefficients, a low degradation rate and remarkable cycling stability positions this Li3V2(PO4)3 material as a promising candidate for advanced energy storage applications. [ABSTRACT FROM AUTHOR]

Ground improvement is a complex issue, and accurately predicting the consolidation and settlement of soft soil with prefabricated vertical drain (PVD) presents a significant challenge. Recent laboratory and field tests have highlighted the influence of the variable discharge capacity of PVD and the non‐Darcian flow behavior of soft soil on consolidation. However, existing theories have not yet considered these two factors simultaneously. To address this gap, a numerical solution for consolidation analysis incorporating non‐Darcian flow and variable discharge capacity of PVD was developed and applied in a test area. The results of this study demonstrate the significant impact of both non‐Darcian flow and variable discharge capacity on the consolidation rate. A comprehensive comparison between the findings of this numerical solution, the degenerate solution, and monitored data reveals clear differences. Notably, the non‐Darcian exponent (s) and discharge capacity parameters (A3) were found to exert a greater influence on consolidation behavior compared to other factors. These findings provide valuable guidance for the design and implementation of following airport ground improvement strategies. [ABSTRACT FROM AUTHOR]

Nowadays, the consumption of fossil fuel resources and the enhancement of environmental pollution are serious problems. One of the best strategies for resolving this issue is to use sustainable and renewable energy sources. Hydrogen, as a clean energy carrier, is a suitable candidate to supply the energy demand in the future and achieve carbon neutrality. Today, storing hydrogen and applying it as a fuel is one of the most significant issues in the world. Hydrogen must be stored in a safe, economical, and reversible. Hydrogen can be stored using nanoparticles. In this study, for the first time, lithium cobalt oxide (LiCoO 2) nanoparticles have been synthesized by a green method using Aloe vera leaves extract. The structure and morphology of the sample have been investigated by means of various techniques. The hydrogen storage capacity of the as-synthesized LiCoO 2 nanoparticles has been measured in alkaline media using the chronopotentiometry technique. The obtained results show the high discharge capacity of 4858 mAh/g, after 11 cycles. [Display omitted] • Pure LiCoO 2 nanoparticles (NPs) were synthesized by an eco-friendly green process. • The optical band gap of LiCoO 2 nanoparticles was about 1.7 (eV). • The LiCoO 2 nanoparticles have mesoporous structures. • LiCoO 2 showed a very high hydrogen storage capacity of 4858 mAh/g. [ABSTRACT FROM AUTHOR]

The implementation of a battery thermal management system (BTMS) is crucial to ensuring the optimal functioning of lithium‐ion batteries (LIBs) within an appropriate temperature range. In this study, BTMS with a combination of paraffin wax (PA), expanded graphite, and copper foam (CF) is investigated. The impact of various optimization strategies on battery surface temperature and discharge capacity is investigated, and charging and discharging experiments are performed at different ambient temperature conditions. Moreover, the influence of copper foam arrangement on BTMS is studied. The experimental results demonstrate that PA/CF can lead to a significant battery surface temperature reduction of up to 11.7%. Compared with the side radial arrangement, the front tangential arrangement of closely attaching copper foam to the battery leads to improved results. However, the variation in arrangement has minimal impact on the surface temperature of the battery in extreme environmental conditions. Under low‐temperature conditions, incorporating phase‐change materials could produce insulating effects that supported maintaining battery capacity. In all, this study shows the potential of designing a high‐performance BTMS and contributes to addressing heat accumulation and capacity attenuation during the use of LIBs. [ABSTRACT FROM AUTHOR]

The electrochemical act of valve-regulated lead acid batteries can be enhanced by conductive materials like metal oxides. This work aims to examine the preparation and influence of zirconia on poly(vinyl alcohol) based gel valve-regulated lead acid battery. Characterizations like Fourier transform infrared spectroscopy, ionic conductivity, water retention study, cyclic voltammetry, electrochemical impedance spectroscopy and galvanostatic charge-discharge techniques were done. The optimized gel system exhibited a discharge capacity of 198.45 μAh cm−2 at the current density of 0.6 mA cm−2. The battery cell with an optimized gel matrix displayed a maximum discharge capacity of 22.5 μAh at a current of 20 μA. After 500 continuous cycles, the battery attained a discharge capacity retention of 91 %. The presence of zirconia will increase the electrochemical performance of gel valve-regulated lead acid batteries.

Nowadays, the active search for an anode material, which can be used in lithium-ion current sources, takes place. The potential anode materials are transition metal oxides (SnO2, NiO and others). In this work, submicron NiO powder was obtained using the thermal decomposition of Ni(CH3COO)2⋅4H2O. Besides, a NiO/C composite anode was fabricated and its behavior in the anode half-cell of lithium-ion current source was studied during multiple cycling. The workability of the anode material was shown and its main energy characteristics were determined. The discharge capacity of the NiO/C anode was 355 mA⋅h/g at the current of C/10 and Coulomb efficiency was 99–100% after 40 cycles.

Abstract In this study, the discharge coefficients (C d) of SMBF flumes under free and submerged flow conditions were analytically investigated. The dimensionless parameters involved in the discharge coefficient, derived from the dimensional analysis, are the contraction ratio [r crn = ratio of flume width (w) to channel width (B)], relative head (h w : the ratio of the upstream head (h) to the $$w$$ w ) and, in the case of submerged flow, also the submergence ratio [ $$S_{{\text{r}}} = h_{{\text{t}}} /h_{{\text{u}}}$$ S r = h t / h u : downstream flow depth ( $$h_{{\text{t}}}$$ h t ) to upstream flow depth (h u)]. C d decreases logarithmically from 1.2 to 0.75 in the range of $$h_{w}$$ h w between 0.4 and 1.8. The submerged condition does not reduce the $$C_{{\text{d}}}$$ C d , but it reduces the discharge capacity (up to 50%), so that in some cases, to pass a given flow discharge, $$h_{{\text{u}}}$$ h u should increase by about 100% compared to the free condition.

Copyright of LHB: Hydroscience Journal is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this study, the discharge coefficients (Cd) of SMBF flumes under free and submerged flow conditions were analytically investigated. The dimensionless parameters involved in the discharge coefficient, derived from the dimensional analysis, are the contraction ratio [rcrn = ratio of flume width (w) to channel width (B)], relative head (hw: the ratio of the upstream head (h) to the w ) and, in the case of submerged flow, also the submergence ratio [ S r = h t / h u : downstream flow depth ( h t ) to upstream flow depth (hu)]. Cd decreases logarithmically from 1.2 to 0.75 in the range of h w between 0.4 and 1.8. The submerged condition does not reduce the C d , but it reduces the discharge capacity (up to 50%), so that in some cases, to pass a given flow discharge, h u should increase by about 100% compared to the free condition. [ABSTRACT FROM AUTHOR]

The piano key (PK) weir is a cost-effective structure for flood discharge. Its typical layout comprises a rectangularly cranked crest in planform with up- and downstream overhangs. With the intention to enhance its hydraulic efficiency, the conventional weir is improved. The sloping floor of each key is modified with a downward semi-circle in the cross-section; each overhanging apex is thus assigned an elliptical crest. Thus, the developed crest length of the resulting weir becomes considerably extended. Experiments are performed to compare the hydraulic behaviors of the improved weir with a reference one. The models are 3D-printed to attain high manufacture precision. For the model dimensions chosen in the study, the developed crest is ~36% longer. The study demonstrates that the improvements in geometry lead to appreciably enhanced flow discharge capacity. Within the hydraulic range examined, the augment in flow discharge varies within a range from 30% to 53%. In terms of both discharge capacity and flow patterns, the improved weir clearly outperforms the conventional one. The elliptical overhang apexes noticeably extend the developed crest length. The streamlined upstream overhang without singularity and the lowered inlet key floor reduce the entrance energy loss and improve the inflow to the inlet key and the flow over the crest. The lowered floor also gives rise to extra water volume, which administers to the flow motion towards the crest. For the outlet key, its lowered floor facilitates the outflow and alleviates the liableness of local submergence at high discharges. If the footprint for spillway construction is limited or the increase in the reservoir water stage must be controlled, the use of a more effective PK weir for flood discharge has significant engineering implications. [ABSTRACT FROM AUTHOR]

In practical engineering, it is common to offset the drainage system axis to avoid conflicts with beams and columns. However, such an offset could significantly affect the system's discharge capacity and drainage safety, leading to a prominent positive pressure above the offset floor. To address this issue, we propose optimizing the system by changing the elbow shapes at the offset position. In our study, we conducted comparative experiments on three elbow shapes, namely, a normal 90° elbow, double 45° elbow, and large curvature elbow, in two experimental systems. Pressure fluctuation and water seal losses were used as experimental parameters to determine the maximum discharge capacity in accordance with the Standard for Capacity Test of Vertical Pipe of the Domestic Residential Drainage System. Our experimental results show that replacing the 90° elbow with the double 45° elbow slightly reduces positive pressure. On the other hand, using the large curvature elbow effectively increases the drainage flow and reduces the positive pressure caused by the upper floor bias. Furthermore, we employed computational fluid dynamics (CFD) software to simulate the flow of water and air in the system, demonstrating the benefits of increasing the elbow at the connecting position. [ABSTRACT FROM AUTHOR]

Sediment deposition is an ecological and environmental problem faced by most water bodies. In view of the poor structural stability and unrepeatable use of existing permeable structures, this paper proposes a cascade permeable dam, which consists of four dam bodies. As the composition of the dam material is the key to sediment interception and discharge capacity, this study sets up two groups of dam material particle sizes for experiments. The results show that the sediment interception performance of the cascade permeable dam is good. When the dam material with a small particle size is selected, the percentage of intercepted sediment mass inside the four dam bodies is 75–89%. The interception sediment rate is much greater than that of the dam material with a large particle size, which tends to decline one by one along the flow direction. The discharge capacity of the dam gradually decreases with time, and there is an obvious decrease in the permeability coefficient of 1# dam. The results of this study provide programmatic support for reducing sediment entering shallow lakes and rivers, which can further optimize the structure design of permeable dams. [ABSTRACT FROM AUTHOR]

An important factor for increasing the effectiveness of the PVD (Prefabricated Vertical Drains) is the value of sufficient discharge capacity so that the PVD can work optimally. The use of PVD is usually accompanied by the use of PHD (Prefabricated Horizontal Drains) as horizontal drainage and combined with preloading. In the field, the connection is made by winding the PVD to the PHD and then tying it with cable ties. The connection system can cause deformation at the top of the PVD thereby reducing the effectiveness of the PVD discharge capacity. This study aims to find the optimal PVD-PHD connection system for the discharge capacity which is affected by confinement pressure, overburden pressure, and hydraulic gradient with a PVD-PHD connection system discharge capacity tester. The test specimens used were PVD (5mm thick; 100mm wide) and Ph.D. (20 mm thick; wide: 100 mm, 200mm, and 300mm). 4 types of connection systems have been tried, namely connections A1 and A2 where the PHD is connected in a horizontal position, and connections B1 and B2 where the PHD is connected in a vertical position. Of the four connection systems B1, the connection system has the largest discharge capacity value and a significant increase in PHD width from 100 mm to 300 mm with an increase of 7.694% at 50 kPa overburden pressure and 1.0 hydraulic gradient the highest compared to other connection types. [ABSTRACT FROM AUTHOR]

A compound channel’s discharge capacity and boundary shear force can be predicted as a sum of the discharge capacity of different sub-regions once the apparent shear stress of the dividing line is reasonably quantified. The apparent shear stress was usually expressed as a coefficient multiplied by the difference between two squared velocities of two adjacent regions. This study investigated the range of the coefficient values and their influencing factors. Firstly, the optimal values of the coefficient were obtained based on experimental data. Then, comparisons between the optimal values and several parameters used in quantifying the apparent shear stress were conducted. The results show that the coefficient is mainly related to a morphological parameter of the floodplain and the ratio of resistance coefficients between the floodplain and the main channel. An empirical formula to calculate the coefficient was developed and introduced to calculate the flow discharge and boundary shear stress. Experimental data, including 142 sets of test data of symmetric-floodplain cases and 104 sets of one-floodplain cases, have been used to examine the prediction accuracy of discharges and boundary shear stress. For all these tests, the ranges of water depth of the main channel and the total width of the compound cross-section are about 0.05~0.30 m and 0.3~10 m, respectively; the Q range and the range of Froude numbers of the main channel flow are about 0.0033~1.11 m3/s and 0.3~2.3, respectively. Comparison with other methods and experimental data from both rigid and erodible compound channels indicated that the proposed method not only provided acceptable accuracy for the computation of discharge capacity and boundary shear stress of compound channels in labs but also gave insights for calculating discharge capacity in natural compound channels.

Potassium–oxygen batteries (KOBs) are a promising energy storage technology with high theoretical energy density, low overpotential and a long cycle life. The cathode microstructure plays a significant role in the electrochemical performance of KOB. In this article, hierarchical porosity was introduced to commercially available carbon paper cathodes by thermal pretreatment in air at different pretreatment times. This pretreatment modifies the properties, such as surface area, defects, oxygen functional groups, etc. The discharge performance was determined at three different current densities, i.e., 0.1 mA/cm2, 0.5 mA/cm2, and 1.0 mA/cm2. It has been found that an increase in specific surface area with the introduction of micropores and mesopores is beneficial for the improvement in the discharge capacity by enabling homogeneous discharge product, KO2 distribution and high degrees of pore filling over the volume of the cathode. A reduction in the discharge overpotentials was observed, which is attributed to the introduction of oxygenic functional groups and defects. Samples treated for the longest pretreatment time of 24 h showed the highest discharge capacity of 5 mAh/cm2 and lowest discharge overpotential of 0.03 V.

The electrochemical characteristics of the negative electrodes of the lead-acid battery with additives of carbon nanotubes and graphene were studied. It was shown that the highest values of the capacitive characteristics of the electrodes were obtained by adding carbon nanotubes to the negative active mass. The processes occurring on the negative electrode were studied by the method of impedance spectroscopy. Applying simulation, an equivalent electrical circuit was obtained, which adequately approximated the obtained frequency dependences. The elements of the proposed equivalent circuit were calculated. It was found that the injection of carbon additives increases the resistance R3 related to the porous structure of the electrodes.

Flood is a general issue that can lead to the life and safety of residents. One of the problems is the lack of capacity in the drainage system in a residential area. This paper will analyze the drainage system based on the capacity in one of the residential clusters. The method for the drainage system performance in hydrology analysis was carried out with Log Person, and the return period for rainfall duration is ten years (R10) for hydraulic analysis using drainage system modeling with EPA – SWMM 5.1. The result based on hydrological is the precipitation for flood forecasting is 159.79 mm. It is found that the drainage capacity is filled in downstream of the main drain with a maximum discharge of 2.726 m3/s and secondary drains with a maximum discharge of 0.624 m3/s. Improvements were made to resolve the insufficiency of the existing channels by running two different scenarios: (1) Re-design the dimensions of the main and secondary channels, (2) Implement a detention pond, as well as re-design the dimensions of the secondary channels. Both scenarios could overcome the flood problem. Scenario 2 shows a higher reduction in the flow discharge at the downstream channel compared to scenario 1.

Lead-Acid Batteries (LABs) remain a popular choice for energy storage due to their wide availability and reasonably low cost, but they exhibit a shorter cycle life and are non-eco-friendly. The objective of this study was to evaluate the discharge capacity of a flooded lead-acid battery using an electrolyte modifiedwith additives from natural plant extracts -Hibiscus Sabdariffa (H–S) and Bidens Pilosa (B–P) plants. The study utilized commercial LABs with electrolyte solutions of 100% sulfuric acid and varying volumes of plant extract solutions at concentration of 10% (w/v), 15.86% (w/v), 30% (w/v) and 44.14% (w/v). The effect of the additives was assessed by comparing the charge-discharge cycle times, coulombic efficiency and energy efficiency. The results show the longest measured discharge time of 4.63 h at 15.86% (w/v) of H–S additive-electrolyte solution, 0.13 h longer than for the standard electrolyte. The highest coulombic efficiency (CE) was 97.3% at 44.14% (w/v) of H–S additive electrolyte solution, 10% above the standard electrolyte. The highest value for energy efficiency (EF) was 83.8% achieved in the battery with 44.14% (w/v) H–S additive electrolyte solution. The best recorded performance with B–P additive electrolyte solution was, CE of 94.6% and EF of 81.3%, obtained at 15.86% (w/v) additive concentration. It is evident from the results that bio-active compounds present in the additive solution of plant extracts influenced the electrochemical performance of the battery. The novelty of this work lies in the choice of candidate plants named, H–S and B–P for green extracts and the methodology of extraction, which is low-cost, eco-friendly and sustainable. This study contributes to fundamental understanding and strategies towards economical and eco-friendly plant electrolyte batteries.

ABSTRACTIn the field of water conservancy engineering, a spillway is a common hydraulic structure that plays a role in flood discharge and dam protection. The selection of the weir surface curve and shape scale of the spillway is significant, and the physical shape of the spillway flip bucket is a critical factor affecting the flood discharge and energy dissipation of the spillway. This paper focuses on a hydraulic model study of the Dashijian Reservoir spillway. The physical shape of the spillway was modified several times during the experiments; the results show that the left and right buckets consist of circular arcs with radii of 13.7 m and 10.01 m, respectively, and the middle bucket consists of a circular arc with radius 11.79 m. The flowing water tongue form is good, the energy dissipation effect is good, and the scouring and deposition form of the downstream riverbed is acceptable. The results of the study can be a valuable guideline for the design of the flip bucket shape of the drainage building.

Scandium and Niobium doped Lithium Titanate is prepared by a sol-gel technique based on the formula Li4-x ScxTi5-y NbyO12, where x = y = 0.0 & 0.3 i.e. Li4 Ti5 O12 and Li3.7 Sc0.3 Ti4.7 Nb0.3 O12. The specific capacity of Sc and Nb incorporated LTO has been observed as 227.5 mAhg-1 at 1 c, while this value has shown a decrease in the value of the specific capacity of the electrode i.e. 105.5 mAhg-1 at 20 c even after many test cycles. It has also been observed that Sc-Nb doping is suitable for the reversible cycle of the battery system and the extraction of Li+. [ABSTRACT FROM AUTHOR]

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To meet the functional requirements of high-rise buildings, drainage stacks usually employ an offset pipe in the structural transfer floor. At the offset point, the flow direction changes and the air pressure fluctuates, which significantly influences the drainage system capacity and water seal effectiveness. Different offset modes have different degrees of influence on drainage characteristics. To better understand the influence of different offset modes on drainage characteristics, five different test conditions in double stack building drainage systems were established and investigated. DS1 was a standard double-stack drainage system with anti-reflux H-tube joints for every two floor levels. The remaining four systems were developed from DS1 by adopting various offset pipes (or pipe joints) on the fourth floor. DS2 adopted an S-shape offset pipe joint at the offset point. DS3 adopted double S-shape offset pipe joints. DS4 adopted a 1.0-m-long horizontal offset pipe. DS5 adopted a 1.5-m-long horizontal offset pipe. The pressure fluctuations and water seal losses were chosen as the experimental parameters to determine the maximum discharge capacity according to the Standard for Capacity Test of Vertical Pipe of the Domestic Residential Drainage System CJJ/T 245. The experimental results demonstrated that the installation of offset pipes (or pipe joints) contributed to the abrupt positive pressure and severe water seal losses at the position where flow direction shifted. As the length of the offset pipe increased, the positive pressure was more severe, and maximum discharge capacity was minor. The relationships among the maximum discharge rate, pressure fluctuation limits, and water seal losses are discussed. Lastly, a nondimensional analysis was adopted to understand the relationship between water seal losses and pressure limit values under different discharge rates for current test facilities. Practical application: Pipe offset has the potential to influence a drainage system discharge capacity. As the length of the horizontal offset pipe increases, the discharge capacity will decrease. In the actual design, the length of the offset pipe section should be reduced and this study demonstrates that the application of S-shape offset pipe joints is an efficient solution. [ABSTRACT FROM AUTHOR]

Piano key weirs (PKWs) with crown parapet walls effectively manage water levels and maximize storage. However, their efficiency is compromised by interactions between water flow and submerged outlets during rising water levels. This study investigates novel parapet wall designs to improve PKW performance and reduce submergence effects. The experiment focuses on a PKW with a fixed 12.6 cm weir height. Three parapet wall configurations are tested: Mode 1 (walls on all apex), Mode 2 (walls fixed on sides and inlet), and Mode 3 (walls along the sides). Each mode includes three parapet wall profiles: rectangular (consistent form), triangular, and trapezoidal (varying characteristics). Results indicate that parapet wall design significantly affects water level variations with increasing wall height. Mode 3, featuring triangular and trapezoidal parapet walls, demonstrates the highest discharge capacity among the examined profiles. The discharge coefficient correlates with parapet wall height and form. Notably, the triangular wall in Mode 3 outperforms Modes 1 and 2 when parapet walls maintain an R/P ratio of 0.36. This study introduces innovative parapet wall designs to enhance PKW efficiency. By implementing advanced configurations, significant improvements in water control and discharge capacity can be achieved. These findings contribute to the state-of-the-art in PKW technology and offer valuable insights for practical engineering applications. [ABSTRACT FROM AUTHOR]

Compositions of ultrafine Si and C particles are promising anode materials for lithium-ion power sources with improved energy characteristics. In the work, samples of lithium-ion power sources with an anode made of ultrafine SiC fibers, as well as mixtures of SiC fibers with graphite (C/SiC) and electrolytically deposited submicron silicon fibers (C/Si/SiC) were fabricated and studied for energy characteristics. The working ability of the mixtures obtained during lithiation/delithiation was shown, and the main energy characteristics of the investigated anode half-cells were determined. After 100 cycles, the SiC anode reached a discharge capacity of 180 and 138 mA⋅h/g at a charge current of C/20 and C, respectively. Anodes made of mixtures (wt%) 29.5C-70.5SiC and 50Si-14.5C-35.5SiC show discharge capacities of 328 and 400 mA⋅h/g at a charge current of C/2. The Coulomb efficiency of all samples was above 99%.

The deep tunnel stormwater system, consisting of dropshafts and underground tunnels, is used to alleviate or prevent urban water problems associated with extreme rainfall events. The stepped dropshaft can transport surface runoff to the tunnels with high energy dissipation, low risk of cavitation and good exhaust performance, which well meets the requirement of the deep tunnel stormwater system. In the present study, the characteristics of the standing wave were investigated by experiments and numerical simulations, including the peak, trough and length of the standing wave. The flow regimes were divided into the nappe flow, the transition flow and the skimming flow with the increase of discharge, in which the standing wave mainly occurs on the external wall under the nappe flow and the transition flow. Influences of inflow discharge and dropshaft geometries were analyzed, including step rotation angle, relative step height and dropshaft curvature. The relations of the characteristics of standing wave with these effect factors were obtained. The maximum discharge capacity of the stepped dropshaft was established by considering that the standing wave just reached the above steps, which could be useful for the design and safe operation of the stepped dropshaft. HIGHLIGHTS The standing wave properties under various flow regimes in stepped dropshaft are demonstrated and compared.; The major factors affecting the standing wave properties are obtained and their influences are concluded.; The maximum discharge capacity of stepped dropshaft is predicted based on the knowledge of standing wave peak.;

Li3V2(PO4)3 cathodes for Li-ion batteries (LIBs) were synthesized using a hydrothermal method with the subsequent annealing in an argon atmosphere to achieve optimal properties. The X-ray diffraction analysis confirmed the material’s single-phase nature, while the scanning electron microscopy revealed a granular structure, indicating a uniform particle size distribution, beneficial for electrochemical performance. Magnetometry and electron spin resonance studies were conducted to investigate the magnetic properties, confirming the presence of the relatively low concentration and highly uniform distribution of tetravalent vanadium ions (V4+), which indicated low lithium deficiency values in the original structure and a high degree of magnetic homogeneity in the sample, an essential factor for consistent electrochemical behavior. For this pure phase Li3V2(PO4)3 sample, devoid of any impurities such as carbon or salts, extensive electrochemical property testing was performed. These tests resulted in the experimental discovery of a remarkably high lithium diffusion coefficient D = 1.07 × 10−10 cm2/s, indicating excellent ionic conductivity, and demonstrated impressive stability of the material with sustained performance over 1000 charge–discharge cycles. Additionally, relithiated Li3V2(PO4)3 (after multiple electrochemical cycling) samples were investigated using scanning electron microscopy, magnetometry and electron spin resonance methods to determine the extent of degradation. The combination of high lithium diffusion coefficients, a low degradation rate and remarkable cycling stability positions this Li3V2(PO4)3 material as a promising candidate for advanced energy storage applications.

[Display omitted] The effect of various types of electrolytes on the operation of coordination polymers based on NiII or CuII in lithium-ion batteries has been examined. Cyclic voltammetry, galvanostatic cycling and quantum chemical modeling have been used to study the processes of lithiation and delithiation. It was shown that the use of a new electrolyte based on a mixture of 1 M LiN(CF 3 SO 2) 2 in 1,3-dioxolane–1,2-dimethoxyethane and 1 M LiPF 6 in ethylene carbonate–dimethyl carbonate improved battery performance, while cycling in the range of 0.2–2.5 V increased the discharge capacity up to 177–188 mA h g−1 and stabilized the charge–discharge processes. [ABSTRACT FROM AUTHOR]

To investigate the influence of different clogging degrees of a street inlet on its discharge capacity, an experimental campaign with the clogging degree of inlet grate and connection tube varying from 0.0 to 0.75 were conducted in a double-layer flume platform with a horizontal bottom. A total of 608 experimental runs were conducted in a subcritical state, with the inflow discharge and surface water depth varying from 24 L/s to 45 L/s and from 0.022 m to 0.38 m, respectively. To facilitate the application of the unified formula under different clogging scenarios, a parameter termed the clogging decay coefficient was introduced. The relationship between clogging decay coefficient and clogging degree was proposed respectively for the clogging of grate and connection tube. The proposed unified formula has several advantages, including a simple structure, a better accuracy, and without the necessity to select different discharge coefficients. [ABSTRACT FROM AUTHOR]

Labyrinth side weirs have significant advantages according to conventional side weirs in terms of discharge capacity. Labyrinth side weirs are especially advantageous in places where more discharge is required from small weir openings lengths. The most significant feature of labyrinth side weirs is their effective crest length, which enables them to discharge more flow. In this study, the situation where the discharge capacity is decreased due to the narrowing of the crest length of the labyrinth side weir for any reason was experimentally investigated in detail. It was also considered that the potential narrowing could be in the upstream weir crest length. The overflow from the remaining length of the crest was enabled by the 1/3, 2/3, and 3/3 closure of the upstream crest length of the labyrinth side weir. Therefore, it was attempted to determine the decrease in discharge capacity due to the narrowing in the effective crest length. The values of the discharge coefficient were obtained by using the De Marchi approach. The study was conducted for subcritical flow regimes and steady-state flow conditions. A total of 980 experimental runs were conducted in this study. As the length of upstream effective crest length of the triangular labyrinth side weir at the straight channel decreases, the discharge coefficient also decreases. By narrowing the length of effective upstream crest length in 1/3, 2/3, and 3/3 ratios, the total discharge capacity decreased by approximately 10%, 23%, and 48%, respectively. [ABSTRACT FROM AUTHOR]

The influence of the ultrasonic field on lead dioxide electrodeposition from nitrate electrolyte was studied. The adsorption of electroactive particles and the amount of nucleation on the electrode surface were found to have increased as well as the formation of OH-radicals accelerated under the influence of the ultrasonic field. Fine-crystalline deposits of lead dioxide were formed, which contributed to obtaining high current yield of lead dioxide, coefficient increasing of the electrode active mass and increasing of the discharge capacity of the emergency current generator cell layout. It was shown that the application of ultrasound in producing a lead dioxide electrode made it possible to reduce the time of the technological procedure.

Labyrinth weirs are complex hydraulic structures. They have been widely used as a water regulator and to increase discharge in channels and spillway dams. Labyrinth weirs are an economical and effective method to pass large floods. In addition, they are used to reduce the requirements of the structural footprint. These features make them an interesting and appropriate choice to increase the capacity of discharge. Several factors affect the discharge capacity and the hydraulic performance of labyrinth weirs, including water level to crest height ratio, angle of sidewalls, apex width, conveyance channel conditions, and vertical aspect ratio. The present paper aims to summarise the most relevant knowledge of the hydraulic characteristics of the labyrinth weirs reported in previous articles. The importance of the present study is to provide a better understanding of how these weirs operate, in addition to which future studies deserve further investigation. The results demonstrated that some parameters still need further investigation. Also, energy dissipation over the labyrinth weir needs further investigation with different weir geometry. Furthermore, the results showed that common design equations did not take into account all parameters affecting labyrinth weir performance, including geometries, flow conditions, site conditions, and scale effect. In addition, machine learning techniques need further study. HIGHLIGHTS The highlights of this review article are as follows:; • The physical modelling was reviewed.; • The numerical modelling was reviewed.; • The design methods of labyrinth weirs were reviewed.; • Machine learning techniques were reviewed.; • The present review article provides a scope of future works of labyrinth weirs.;

Abstract The spillways are one of the most important hydraulic structures used in river engineering, dam construction, irrigation, and drainage engineering projects. Recently, a new type of such spillways with a circular crest has been proposed. In this paper, the hydraulic properties of the circular crested stepped spillway (CCSS) including flow pattern, distribution of velocity on the crest and pressure, turbulence intensity, discharge coefficient ( $${C}_{d}$$ C d ) and energy dissipation ratio (EDR) were investigated numerically. To model the free surface of flow the volume of fluid technique, and for modeling the turbulence of flow, k − ε (RNG) was utilized. Results declared that there is a good agreement between the laboratory observations and numerical simulation. The $${C}_{d}$$ C d of the CCSS changes between 0.9 and 1.4 considering the range of relative upstream head ( $${h}_{up}/R$$ h up / R ) between 0.33 m and 2.67. The observation of the flow streamlines showed that they are tangential to the curvature of the crest and there is no separation of the flow from the crest. Examination of the pressure distribution on the CCSS model shows that just downstream part of the crest, the pressure is partially negative. Of course, the same partial negative pressure is observed on the edge of the steps. The steps increase the maximum intensity turbulence by 50%. The CCSS can dissipate the energy of flow between 90 and 30%, and in the skimming flow regime, the portion of each step in the energy dissipation regardless of their position is almost identical.