Inaccurate Assessment Research Articles

Analysis of the stability of cracked soil slopes using a numerical model incorporating stochastic theory

Desiccation crack is a prevalent natural phenomenon that plays a significant role in the stability of soil slopes. In this study, a hydromechanical coupling model incorporating a layer of stochastic cracks is developed for analyzing cracked soil slopes. To properly consider the anisotropy and spatial variability of desiccation cracks, three crack indices are generated through cross-correlated random fields via Cholesky decomposition. The seepage and mechanical behavior of a cracked slope are analyzed by adjusting stochastic parameters and rainfall conditions. Applied to the Ningzhen Mountains area in China, the model investigates the stability of slopes under various annual meteorological conditions. The results indicate that neglecting the spatial variability of cracked layer properties can lead to inaccurate assessments of instability risks at the base and water accumulation at the top of slopes. During heavy rainfall, slopes with deeper (up to 5 m) and weaker cracked layers often show a roughly planar sliding morphology. Moreover, the uncertainties in crack depth have the most pronounced influence on the uncertainties of the slope stability, more than horizontal permeability or crack aperture. The average crack aperture’s influence on slope stability depends on the relationship between crack infiltration rate and rainfall intensity.

Modeling of virtual synchronous controlled-DFIG considering stator voltage control dynamics for transient stability analysis

Transient stability of virtual synchronous controlled (VSynC) equipment is usually analyzed without considering the dynamics of the AC voltage controller. However, neglecting the impact of stator voltage controller dynamics in doubly fed induction generator (DFIG) wind turbine can lead to inaccurate stability assessment results. In this paper, the quantitative analysis of the impact of non-forced magnetic flux and DC voltage fluctuations on transient stability is conducted. Based on these analyses, a simplified DFIG model is proposed, which is approximately equivalent to a synchronous generator with excitation regulator. Then, a discretized step-by-step calculation procedure is introduced for the proposed model. Moreover, the influence of controller parameters on transient stability is analyzed based on the calculation results. Finally, simulations and experimental validations are carried out to demonstrate the effectiveness of the proposed model.

Optimal maintenance policy for imperfect production systems using reliability function and defect rate

AbstractThis study examines how a manufacturer can improve the robustness of an imperfect production system by implementing maintenance activities, which can be measured in terms of system reliability and product failure rate. A two‐dimensional maintenance policy comprising system reliability and the product defect rate is proposed to assess maintenance activity costs. The optimal thresholds of the two dimensions are analyzed to investigate the trade‐off between cost and system quality. A numerical example is provided to verify the proposed model's effectiveness. The results showed that the less stable the system, the greater the total costs incurred; therefore, lower stringent thresholds may be set to prevent frequent maintenance. Moreover, a sensitivity analysis is performed to investigate the essential parameters that significantly affect maintenance decisions. The results showed that the thresholds of the reliability function and defect rate significantly impact total costs. Any inaccurate assessment of system usage could lead to incorrect estimations and a substantial increase in cost.

Reassessing the warming impact of methane emissions from Irish livestock using GWP*: historical trends and sustainable futures

Methane from livestock production contributes significantly to Ireland’s greenhouse gas emissions. Methane emissions are generally expressed as carbon dioxide equivalents (CO2e) using the global warming potential (GWP) metric, but this conversion may result in an inaccurate assessment, because methane has a much shorter atmospheric lifespan than CO2. This study calculated the CO2e of methane emissions from Irish livestock using the GWP and GWP* metrics, the latter of which accounts for the short-lived nature of atmospheric methane. Methane emissions from all Irish livestock (1961–2020) were included and three projected scenarios to 2050 were hypothesised: increasing emissions, decreasing emissions and constant emissions. The CO2e of methane from Irish livestock was found to be influenced by changes in the rate of emission over the preceding decades. Using the GWP* metric, declining populations of donkeys and horses from 1961 to 2000 were shown to cause atmospheric removals of methane when expressed as CO2e. Increasing populations of swine and non-dairy cattle (in response to industrial changes and European Union [EU] regulations) saw significant increases in the CO2e of methane emissions from these sources. Milk quotas caused a significant reduction in the CO2e of methane emissions from dairy cows, and atmospheric removals were observed in the years 1990–2012. GWP* indicated that the constant and decreasing future emission scenarios gave more significant reductions in CO2e than the GWP. These results indicate the importance of the effect of emission rate on the CO2e of methane from Irish livestock, which is accounted for using GWP*, but not by the conventional GWP.

Ռուսաստանի կայուն առևտուրն անկայուն աշխարհում / STABLE TRADE OF RUSSIA IN AN UNSTABLE WORLD

Currently, Russia holds the top position globally in terms of the number of sanctions imposed on the country. Over the past two years, the increasing number of restrictions imposed by Western countries has been aimed at isolating the Russian economy from global markets, with the intention of ending the war by causing economic hardship. Immediately after the start of the war, the country's authorities ceased regular publication of foreign trade statistics to avoid inaccurate assessments and speculation. The paper , attempted to analyze Russia's foreign trade activity over the past two years using mirror data from partner countries, as well as aggregated official statistics from the Russian Federation. Due to the sanctions, the Russian economy experienced notable declines, especially following the embargo placed on crude oil and petroleum products in 2023. Yet, they are far from the expectations of Western countries. On the one hand, Russian companies find ways to circumvent the sanctions, on the other hand, trade also shifts towards markets of "friendly" countries.

Extended power to hydrogen operations for enhanced grid flexibility in low carbon systems

Power-to-hydrogen (P2H) systems are increasingly recognized as a promising solution to expedite the integration of Renewable Energy (RE) in various energy sectors. P2H in Hydrogen Consuming Industries (HCIs) can serve hydrogen demands and the much-needed flexibility for power system operations. However, consideration of these systems for significant industrial and power sector use cases requires modelling fidelities for exact operational and economic reflections. P2H operational modelling for flexibility focuses on excess renewable energy evacuation and storage only while often oversimplifying their models by using constant efficiency models or neglecting specific Hydrogen Electrolyzer (HE) overvoltage components. Under variable operations and downstream HCI demands, this can lead to inaccurate assessments, undermining existing flexibility quantum from HCIs. Another prevalent issue with P2H adoption is its costs, which are directly linked with P2H operating ranges. These systems are presently modelled with constrained operations, leading to increased costs and limited ability to provide grid services. Therefore, appropriate modelling of HCIs considering P2H device working characteristics and its inherent flexibilities is essential. It can allow cost-effective operations and the exchange of accurate flexible margins with electrical grids. In this regard, this work proposes a comprehensive extended electro-chemical HE model for HCIs allowing high current density working through the extended operation of P2H. The considered model inherits intrinsic working characteristics of electrolyser operation, i.e., variable current, nonlinear efficiency, and loading, to cater to the hydrogen demands of HCI. The effect of high current density operations is elucidated through device operations under reaction kinetics. The results highlight that the proposed model integrated with the electrical grid provides actual operational costs and flexibility margins. A comparison of various modelling approaches and their effect on adjustable margins demonstrates a considerable difference in P2H loading, working efficiency, operating costs, and adjustable margins with the proposed model.

Innovative determination of the specific anammox activity for anammox sludge from continuous flow reactors: A comparison between continuous flow test and batch test

A novel method for measuring specific anammox activity (SAA) was proposed based on continuous flow tests to accurately determine the SAA of anammox sludge from continuous flow reactors, resolving the challenges of inaccurate SAA assessment caused by substrate shock to anammox bacteria. Results showed SAA of expanded granular sludge bed sludge via batch tests (0.101 ± 0.018 g-N·g-VSS-1·d-1) was lower than continuous flow tests (0.206 ± 0.010 g-N·g-VSS-1·d-1) (p < 0.05), highlighting the impact of substrate shock. Conversely, SAA of sequencing batch reactor sludge assessed via batch tests (0.878 ± 0.008 g-N·g-VSS-1·d-1) was higher than continuous flow tests (0.809 ± 0.005 g-N·g-VSS-1·d-1) (p < 0.01), attributed to endogenous denitrification. The advantages of continuous flow tests over batch tests included milder feeding way, stricter anaerobic conditions, and minimal sampling impact on system. Our study contributes to more accurate measurements of SAA of anammox sludge from continuous flow reactors, favoring long-term robust operation of anammox reactors.

Loading protocols for quasi-static cyclic testing of flexure dominated reinforced concrete circular bridge columns under crustal, subcrustal, and subduction earthquakes

Experimental procedures involving quasi-static cyclic tests have been the most prevalent for seismic performance assessments of structural and non-structural components and systems. However, there is a lack of consensus among experimentalists and researchers on a standard loading protocol. This study aims to propose a set of standard loading protocols representative of the seismic demands imposed on typical flexure dominated reinforced concrete bridge columns under uniaxial bending. Variable parameters: axial-load ratio, aspect ratio, longitudinal and spiral reinforcement ratios, concrete compressive strength, and steel yield strength were initially screened for significance in terms of their influence on the number of inelastic cycles and cumulative displacement ductility - two key reference parameters for the development of loading protocols. The number of inelastic cycles cumulative displacement ductility were then determined for reinforced concrete bridge columns having unique combinations of upper and lower levels of the significant parameters under different earthquake types (crustal, subcrustal, subduction) and displacement ductility demand levels (2, 4, 8). These target ductility demands intend to capture a wide range of structural responses including minimal and collapse damage states. Statistical analyses revealed that for the considered bridge columns, it is feasible to develop one representative loading protocol for each earthquake type and target displacement ductility demand level. Hence, nine loading protocols were proposed and then compared against equivalent loading protocols found in standards and literature. Standard protocols were found to impose unrealistic damage on bridge columns subjected to crustal and subcrustal earthquake hazards leading to inaccurate assessments. The proposed loading protocols for subduction earthquakes had a comparable number of inelastic cycles to those found in the literature for the same earthquake hazard and are representative of the seismic demands imposed on bridge columns.

Toplulukları Güçlendirmek: Bangladeş’te Covid-19 Sonrası Zekat Dağıtımını Yeniden Tanımlamak

Poverty persists as a global challenge, particularly in economically underdeveloped Islamic countries. Despite government efforts to address income inequality and reduce poverty, these issues continue to afflict societies. To effectively confront this pressing problem, it is imperative to scrutinize the impact of Zakat, a crucial institution in Islam, and its potential contribution to alleviating these challenges. Zakat, one of Islam's five pillars, plays a pivotal role as a guiding economic force and a form of worship. It serves as a means of social assistance and solidarity, fostering stronger bonds between the donor and the recipient. Zakat cultivates feelings of love, compassion, and mercy while also mitigating jealousy, envy, and hostility. Furthermore, it operates as a mechanism for income redistribution in societies marked by unequal wealth distribution. This long-standing practice is rooted in the belief that wealth is a trust from Allah and underscores the importance of sharing it with those in need. Zakat has the potential to address a range of economic issues, from supporting the marriages of impoverished individuals to tackling unemployment. It remains significant as an expression of social responsibility and a means to promote justice and compassion, ultimately creating a more equitable income distribution. The objectives of Zakat are multifaceted, encompassing goals such as poverty alleviation, wealth redistribution, strengthened social bonds, wealth purification, meeting basic needs, and empowering vulnerable individuals. However, in Muslim-majority countries such as Bangladesh, the impact of zakat distribution is often inadequate due to a lack of self-discipline and understanding among Muslims. Additionally, the economic recession triggered by COVID-19 has exacerbated poverty in Bangladesh, with adverse effects on employment and a significant increase in poverty rates among low-income workers. Fair and Shariah-compliant zakat distribution remains underutilized in these regions, including South Asian countries within the Organization of Islamic Cooperation. The ease of collective cash or clothing distribution in zakat practices has led to inaccurate assessments of the genuinely needy. This traditional approach has also drawn criticism for its deviation from Islamic principles. This study examines changing perceptions and practices of zakat distribution in Bangladesh, focusing on promoting effective and equitable distribution methods. These methods may include income-generating expenditures, vocational training, microfinance initiatives, and targeted cash transfers. By adhering to Zakat's authentic principles and purposes, Bangladesh can leverage its potential to alleviate poverty and foster a compassionate society per Islamic teachings. Emphasizing the importance of Zakat and applying it fairly can drive significant progress in poverty reduction and social development in Islamic countries like Bangladesh. This study seeks to explore innovative approaches to zakat distribution that align with contemporary economic challenges and societal dynamics, ultimately contributing to a more equitable and prosperous future for the people of Bangladesh. As a result, poverty remains an ongoing problem in Islamic countries, and Zakat is a powerful tool to overcome this problem. By revising and improving the zakat distribution practices in Bangladesh, where the principles of Islamic economics guide efforts to reduce poverty and increase social welfare, work can be done toward building a more just and compassionate society.

Quality of life of patients with singleand multigland parathyroid disease in sporadic primary hyperparathyroidism before and after surgical treatment

Background. In 15–25 % of cases, the cause of primary hyperparathyroidism (PHPT) is multigland parathyroid disease. The complexity of clinical and laboratory prognosis, low efficiency of imaging methods, inaccurate assessment of the radicality of the surgery are the components of the problem of this variant of the disease. Quality of life (QOL) is an important criterion for the effectiveness of surgical treatment. A study of the QOL in patients with multigland parathyroid disease in PHPT has not been previously conducted in our country. The aim of the study. To assess the quality of life of patients with single- and multigland parathyroid disease in sporadic primary hyperparathyroidism before and after parathyroidectomy (PTE). Methods. As part of a prospective observational study, the quality of life of 64 patients with PHPT before and after PTE was assessed using SF-36 (Short Form 36) questionnaire: main group (n = 13) – patients with multigland parathyroid disease; comparison group (n = 51) – patients with single-gland parathyroid disease. The quality of life indicators of the patients were compared with those in a sample of the Irkutsk region population similar in gender and age. Results. Before performing PTE, the quality of life of patients with PHPT was lower than that of the Irkutsk region population. The greatest decrease in both health components was registered in the main group. In 90 % of patients, the quality of life improved after PTE, while in the main group changes were established 1 year after the surgery, in the comparison group – 6 months after the surgery. Transient complications (laryngeal paresis) and disease outcomes (hypocalcemia, hypoparathyroidism) did not interfere with the improvement of quality of life in both groups. When persistence was detected, no significant improvement in QOL was established. Conclusion. The quality of life of patients with PHPT is significantly reduced. PTE improves the QOL of these patients, and only persistence of the disease does not allow this to be achieved. Therefore, surgical tactics aimed at reducing the frequency of persistence will achieve a decent quality of life in the majority of patients with multigland parathyroid disease in PHPT.

Влияние точности оценки успеваемости на эффективность обучения в вузе

Progress control is an essential component of the educational process in universities. Assessment influences students’ motivation and learning strategies, as well as curriculum development. Errors in assessment cause distortions in the feedback of the student-teacher system and lead to a decrease in the effectiveness of teaching. The paper examines the influence of the accuracy and reliability of academic performance assessment on the effectiveness of learning at the university. The methodological basis of the study was the methods of conceptual modeling, analysis of scientific publications and generalized practical experience. A conceptual model of the impact of grades on students’ learning has been proposed and researched. It is shown that with a positive systematic shift in the average teacher error, the quality of learning decreases. The impact of inaccurate assessments on students’ motivation is also considered. Ways to increase the objectivity of academic performance assessment are proposed: formalization of grading criteria, a grade-rating system, the use of standard test programs and collegiate assessment methods. It is anticipated that future research in this area will focus on innovative assessment methods, the impact of technology on assessment accuracy, and the role of collegiate and self-assessment in improving reliability.

Validation for the effect of intra-exposure patient motion on the assessment of radiostereometric implant migration in a tibial component phantom study

BackgroundAn increasing number of radiostereometry (RSA) research studies have long-term follow-up implant migration outcomes, which show ascending curves of implant migration with occasionally decreasing migration. After scrutinizing images and RSA scenes related to the alternating curves, we suppose that intra-exposure patient motion may contribute to that. The main purposes of this in vitro study were 1) to identify whether the patient motion in different directions could result in the inaccurate assessment of implant migration, and 2) to figure out which direction(s) accounted for the alternating curves. HypothesisIt was hypothesized that the assessments of implant migration would be less precise and accurate than they could be when patient motion occurred, and such motion would contribute to the alternating curves of radiostereometric implant migration. Materials and methodsA customized phantom, assembled with a tibial component, was designed for simulating intra-exposure patient motion during follow-up RSA examinations. Two different Roentgen tubes were used as the current standard of radiology departments. Radiographs were acquired in a uniplanar technical arrangement. Two defined protocols were conducted: one is to simulate implant migration outcomes at post-op, the early stage (6months), and the later stage (2 to 10years) ; during the later stage, the other is to mimic patient motion by phantom motion in the medial-lateral (x), distal-proximal (y), and anterior-posterior (z) axes. ResultsPhantom motion could result in the inaccurate assessment of implant migration, and translations along the medial-lateral (x) axis were the most influenced by patient motion. Motion along the medial-lateral (x) axis could account for the curves with decreasing migration. DiscussionOur assessments of implant migration may be less precise and accurate than they could be when intra-exposure patient motion occurs. We probably neglect the importance of 100% simultaneous exposures, and the influence of patient motion on RSA accuracy and data reliability, due to the difficulty in detecting patient (micro)motion. Electronically synchronized exposures of two paired Roentgen tubes are 100% simultaneous for image acquisition, and they are thus highly recommended for the assessment of implant migration in RSA. Type of study and level of proofnot applicable.

Estimating Underdiagnosis of Patients in Chronically Ill Populations

Diagnosis coding in administrative data is often incomplete and introduces inaccurate assessments of patients’ health outcomes. The underdiagnosis of chronic conditions reduces the ability to correlate that chronic condition with associated comorbidities. We developed a novel framework to use longitudinal records of claims-based diagnoses to identify latent, or undiagnosed, members likely to have a target chronic condition before their first diagnosis of the condition is included in the records. We applied our approach to the chronic condition of adult incontinence using the 5% Medicare sample of a continuously enrolled cohort between 2014 and 2018. We considered fee-for-service Medicare beneficiaries over the age of 65 years. We identified observed and latent members with the chronic condition and then examined its correlation with four comorbidities commonly associated with incontinence: urinary-tract infections (UTIs), dermatitis, slips and falls, and behavioral disturbances. We increased our identification of incontinence from the 11.2% with an observed diagnosis in 2018 to an estimated prevalence in 2018 of 34.7%. Considering the four comorbidities, our approach increased from 38% to 68% the share of UTIs experienced by those with incontinence, from 20% to 41% for dermatitis, from 22% to 54% for slips and falls, and from 26% to 57% for behavior disturbances. Our methodology highlights the importance of more accurately estimating the prevalence of chronic conditions for understanding the true correlation between the chronic condition and comorbidities.

Adapting Economic Evaluation Methods to Shifting Global Health Priorities: Assessing the Value of Health System Inputs

ObjectivesWe highlight the importance of undertaking value assessments for health system inputs if allocative efficiency is to be achieve with health sector resources, with a focus on low- and middle-income countries. However, methodological challenges complicated the application of current economic evaluation techniques to health system input investments. MethodsWe undertake a review of the literature to examine how assessments of investments in health system inputs have been considered to date, highlighting several studies that have suggested ways to address the methodological issues. Additionally, we surveyed how empirical economic evaluations of health system inputs have approached these issues. Finally, we highlight the steps required to move toward a comprehensive standardized framework for undertaking economic evaluations to make value assessments for investments in health systems. ResultsAlthough the methodological challenges have been illustrated, a comprehensive framework for value assessments of health system inputs, guiding the evidence required, does not exist. The applied literature of economic evaluations of health system inputs has largely ignored the issues, likely resulting in inaccurate assessments of cost-effectiveness. ConclusionsA majority of health sector budgets are spent on health system inputs, facilitating the provision of healthcare interventions. Although economic evaluation methods are a key component in priority setting for healthcare interventions, such methods are less commonly applied to decision making for investments in health system inputs. Given the growing agenda for investments in health systems, a framework will be increasingly required to guide governments and development partners in prioritizing investments in scarce health sector budgets.

Influence of tensile stress on the magnetic flux leakage signal of the coated steel belt

ABSTRACT The safety of coated steel belts (CSBs) is crucial for reliable elevator operation, as they are critical components in elevator systems. Magnetic flux leakage (MFL) testing is the preferred non-destructive method for evaluating CSBs due to its high sensitivity. Previous studies overlooked tensile stress's impact on in-service MFL testing of CSBs, potentially resulting in inaccurate defect assessments. This research aims to investigate the impact of tensile stress on the MFL signal of CSBs by developing a theoretical model, conducting finite element simulations, and performing experimental verification. In this paper, the rectangular edge defects are considered as the primary defect type in CSBs, and the applied stress on the CSBs varies from 30 MPa to 160 MPa. Under the above conditions, a linear relationship between MFL signal of CSBs and stress is established based on the simplified Jiles-Atherton model and magnetic dipole model suitable for CSBs. The finite element simulation and experiments further indicate that the MFL signal of CSBs increases linearly with the increasing tensile stress. The primary contributions of this study are establishing an MFL model suitable for CSBs and uncovering the linear relationship between the MFL signal of CSBs and tensile stress.

Accuracy and limitations of preoperative assessment of longitudinal spread of perihilar cholangiocarcinoma.

Although surgical resection offers the only chance of cure of perihilar cholangiocarcinoma and R1 resection has a poor prognosis, there is no consensus on optimal preoperative assessment of its longitudinal spread. We aimed to establish the optimal means of achieving this goal. This was a retrospective, single-center study of 61 patients who had undergone multi-detector row computed tomography, endoscopic retrograde cholangiography, intraductal ultrasonography, and mapping biopsy prior to resection of perihilar cholangiocarcinomas in our institute from January 2010 and December 2021. The most accurate single methods for assessing longitudinal spread were intraductal ultrasonography and mapping biopsy (both 72.1%). A combination of all four assessment methods was accurate in 51 (83.6%) of our patients. Independent risk factors for inaccuracy were Bismuth-Corlette Type IV and high histologic-grade tumors. The R0 resection rate was higher with accurate than inaccurate assessments (90.2% vs. 30.0%, P<0.001). R0 resection was associated with significantly better relapse-free survival than R1 resection (P=0.006). However, overall survival did not differ between these groups. Preoperative assessment of longitudinal spread of perihilar cholangiocarcinomas by four different modalities is optimal, achieving 83.6% accuracy and a 90.2% R0 resection rate.

Situation Assessment of Air Traffic Based on Complex Network Theory and Ensemble Learning

With the rapid development of the air transportation industry, the air traffic situation is becoming more and more complicated. Determining the situation of air traffic is of great significance to ensure the safety and smoothness of air traffic. The strong subjectivity of assessment criteria, inaccurate assessment results and weak systemic assessment method are the main problems in air traffic situation assessment research. The aim of our research is to present an objective and accurate situation assessment method for air traffic systems. The paper presents a model to assess air traffic situation based on the complex network theory and ensemble learning. The air traffic weighted network model was introduced to systematically describe the real state of an air traffic system. Assessment criteria based on the complex network analysis method can systematically reflect the operational state of an air traffic weighted network system. We transformed the air traffic situation assessment into a binary classification, which makes situation assessment objective and accurate. Ensemble learning was introduced to improve the classification accuracy, which further improves the accuracy of the situation assessment model. The model was trained and tested on the dataset of the East China air traffic weighted network in 2019. Its average classification accuracy is 0.98. The recall and precision rates both exceed 0.95. Experiments have confirmed that the situation assessment model can accurately output air traffic situation value and situation level. Furthermore, the assessment results are consistent with the real operational situation of the air traffic in East China.

Influence of desorption hysteresis effects on coalbed methane migration and production based on dual-porosity medium model incorporating hysteresis pressure

Desorption hysteresis affects gas mass transfer and migration in coal seams, which is not considered in current dual-porosity medium models, leading to inaccurate assessment and prediction of gas extraction. This study proposed a desorption hysteresis pressure to address this issue of the gas mass transfer in the model. On this basis, two coupled gas migration models, considering (DGMH) and without considering (DGM) desorption hysteresis effects, were developed incorporating mass transfer, gas desorption, gas seepage, and permeability evolution. The models were solved and compared using the finite element method. The results demonstrate that the DGM model yields higher production assessment compared to the DGMH model. This discrepancy can be attributed to the hysteresis effects, which prevent the matrix gas from supplementing the fractures timely after fracture gas flows into the borehole. The DGMH model shows less mass transfer, coal seam permeability, and gas extraction compared to the DGM model. The desorption hysteresis effects are more pronounced in coal seams with higher permeability. In addition, neglecting hysteresis effects when calculating permeability from field gas production data may result in inaccurate values. The hysteresis effects is recommended to be considered in the prediction of coalbed methane extraction, permeability calculation, and risk control of delayed coal and gas outbursts.

Effects of the ground surface thermal boundary condition on the long-term thermal performance of energy diaphragm walls

Energy diaphragm walls have attracted increasing attention due to their high heat transfer performance. Thus, the factors that affect the thermal performance of energy walls have been investigated to provide insights for further practical applications. Numerical simulation is widely used in energy wall analysis due to the complexity of conducting field tests. Therefore, the choice of boundary conditions in the simulations is crucial; it refers to whether the model reflects reality and has a significant impact on the results. In most cases, the assumed ground surface thermal boundary is not the same (e.g., thermal insulation, constant temperature), and the ground temperature is also assumed to be constant with depth, which may result in a large loss of thermal energy or inaccurate assessment of thermal performance for the energy wall. In this respect, this paper investigates the long-term differences in thermal performance under these boundaries and considers the ground temperature that varies with depth and time, which has not been comprehensively considered before in the analysis of energy walls. The results show that accounting for air temperature or ground temperature variations with depth and time can result in a great increase in thermal performance, e.g., a 34% increase in the cooling thermal load compared with the thermal insulation boundary. In the performed parametric analysis, the results highlight the significant influence of the thermal load and wall height on the thermal differences between these boundaries. These findings provide a reference for choosing ground surface thermal boundaries and better thermal design of energy diaphragm walls.

Impact of Anodic Oxidation Reactions in the Performance Evaluation of High-Rate CO2 /CO Electrolysis.

The membrane-electrode assembly (MEA) approach appears to be the most promising technique to realize the high-rate CO2 /CO electrolysis, however there are major challenges related to the crossover of ions and liquid products from cathode to anode via the membrane and the concomitant anodic oxidation reactions (AORs). In this perspective, by combining experimental and theoretical analyses, several impacts of anodic oxidation of liquid products in terms of performance evaluation are investigated. First, the crossover behavior of several typical liquid products through an anion-exchange membrane is analyzed. Subsequently, two instructive examples (introducing formate or ethanol oxidation during electrolysis) reveals that the dynamic change of the anolyte (i.e., pH and composition) not only brings a slight shift of anodic potentials (i.e., change of competing reactions), but also affects the chemical stability of the anode catalyst. Anodic oxidation of liquid products can also cause either over- or under-estimation of the Faradaic efficiency, leading to an inaccurate assessment of overall performance. To comprehensively understand fundamentals of AORs, a theoretical guideline with hierarchical indicators is further developed to predict and regulate the possible AORs in an electrolyzer. The perspective concludes by giving some suggestions on rigorous performance evaluations for high-rate CO2 /CO electrolysis in an MEA-based setup.