Structural Change Research Articles

Effects of Fe Ions, Ultraviolet Irradiation, and Heating on Microscopic Structures of Black Lacquer Films.

The chemical reaction between Fe and lacquer has been used to create the black color in lacquer coatings since ancient times. Here, the effects of Fe ion addition, UV irradiation, and heating on the microscopic structures of black lacquer films were investigated by using X-ray absorption near edge structure (XANES), extended X-ray absorption fine structure (EXAFS), Fourier transform-infrared spectroscopy (FT-IR), small-angle X-ray scattering (SAXS), and small angle neutron scattering (SANS). The EXAFS result indicated that heating and UV irradiation made the coordination structure of Fe3+ in the lacquer nonuniform, and that heating caused the greatest nonuniformity. The FT-IR, SAXS, and SANS results demonstrated that the microscopic structural changes in the black lacquer films were induced by both heating and UV irradiation, but the changes were different. Heating caused a substantial structural change on the nanoscale, and UV irradiation mainly caused changes in the molecular binding mode. The results provide important knowledge for analyzing archeological lacquer samples and for developing lacquer-based materials. This work also demonstrates the utility of the complementary use of XANES, EXAFS, FT-IR, SAXS, and SANS for nondestructive analysis of black lacquer in precious cultural relics.

The Influence of the Changes in Natural Gas Supplies to Poland on the Amount of Hydrogen Produced in the SMR Reactor

Thanks to investments in diversifying the supply of natural gas, Poland did not encounter any gas supply issues in 2022 when gas imports from Russia were ceased due to the Russian Federation’s armed intervention in Ukraine. Over the past few years, the supply of gas from routes other than the eastern route has substantially grown, particularly the supplies of liquefied natural gas (LNG) via the LNG terminal in Świnoujście. The growing proportion of LNG in Poland’s gas supply leads to a rise in ethane levels in natural gas, as verified by the review of data taken at a specific location within the gas system over the years 2015, 2020, and 2022. Using measurements of natural gas composition, the effectiveness of the steam hydrocarbon reforming process was simulated in the Gibbs reactor via Aspen HYSYS. The simulations confirmed that as the concentration of ethane in the natural gas increased, the amount of hydrogen produced, and the heat required for reactions in the reformer also increased. This article aims to analyze the influence of the changes in natural gas quality in the Polish transmission network caused by changes in supply structures on the mass and heat balance of the theoretical steam reforming reactor. Nowadays, the chemical composition of natural gas may be significantly different from that assumed years ago at the plant’s design stage. The consequence of such a situation may be difficulties in operating, especially when controlling the quantity of incoming natural gas to the reactor based on volumetric flow without considering changes in chemical composition.

Effects of wall cavity and fuel injection pressure on the performance of a non-reacting supersonic combustor

This study numerically investigates the flow field of a non-reacting cavity-configured scramjet (Supersonic Combustion Ramjet) combustor at various fuel injection pressures by solving the 2D Reynolds-Averaged Navier-Stokes (RANS) equations, species transport equations, and Menter SST k-ω model. The aim of this research is to reveal the effects of wall cavity insertion and fuel injection pressure (FIP) on the crucial performance parameters i.e., fuel-air mixing efficiency (MxE), total pressure recovery (TPR), and mass-averaged Mach number (MAMN). Accordingly, two trapezoidal cavities of aspect ratio 7 are introduced on the opposite walls of a rectangular combustor. The combustor entrance is configured with rearward-facing steps and it intakes finite parallel air streams through finite-width inlets. Gaseous hydrogen jets are injected 30 mm downstream from the combustor entrance and 10 mm upstream from the cavity leading edge. FIP is varied according to the fuel-to-freestream pressure ratios (FFPR) of 4.5, 9.0, 13.5, and 18.0. The results of the cavity-configured combustor are then compared with the performance of the combustor in the absence of the wall cavities. The results delineate the change in flow structures with the inclusion of wall cavities and variation in FIP. Insight physics of mixing, total pressure loss, and MAMN in different regions of the combustor are studied and the results are quantified for comparison. MxE in a cavity-configured combustor does not monotonically increase with decreasing FFPR as found in the combustor without wall cavities. The shock-shear layer interactions (SSLIs) play a dominant role in mixing inside the cavity-configured combustor. The results also demonstrate that the insertion of wall cavities can increase fuel-air MxE through the formation of cavity recirculation zones. In the cavity-configured combustor, a maximum of 45% MxE is achieved for FFPR 4.5, which is 4% higher than the value obtained from the combustor without the cavities with an expense of 3% greater total pressure loss.

أهمية اتخاذ القرار في تحسين الذكاء الاصطناعي بالتطبيق على صناع القرار في البنوك الخاصة في اليمن

The objective of this study is to determine the impact of change management on digital transformation initiatives in Yemeni telecom sector. A quantitative approach with analytical and deductive methods was adopted to examine the relationship and determine the impact between change management and digital transformation. The study targeted a population of 902 managers and team leaders in the sector. A questionnaire was developed and distributed to a stratified sample of 226 respondents. The random sample was 25% of each stratum. The questionnaire items were designed to measure the change management dimensions (Change Urgency, Visionary Coalition, Empowerment and Sustainability) and digital transformation dimensions (Technology, Processes, People, Culture and Business Model). The results generated show a highly significant positive relationship between effective change management practices and the successful implementation of digital transformation initiatives (substantial positive coefficient B of 0.786, R2 of 0.62 and high t-value of 29.34, and the extremely low p-value below 0.001). In conclusion, this study indicates that digital transformation initiatives require practicing proper and structural change management practices.

The cohesive management: the football lesson for high-tech organizations

ABSTRACT The purpose of the paper is an empirical verification of model of the cohesive management for business organizations. The cohesive management concept is a particular type of management carried out in top European football clubs. Football clubs are characterized by their far-reaching agility, operate in an extremely competitive reality (the winner takes all!), where success depends on the commitment of highly diverse talents from all over the world. Extensive literature research provided a basis for operationalizing the dimensions of cohesive management (CM) in relation to business. The hypothetical model of the CM was verified by empirical research conducted in 406 companies from Poland and the USA. Research models were tested using SEM and moderated multiple regression. The study revealed that what works in top team football is not outdated in relation to business management (CM structure was confirmed); however, it is impossible to mechanically transfer the solutions developed there (significant changes in CM dimension structures were noted). The study demonstrates the importance of CM for organizational performance, whereby the impact is significantly higher in high-tech organizations.

Silencing NlFAR7 destroyed the pore canals and related structures of the brown planthopper.

Fatty acyl-CoA reductase (FAR) is one of the key enzymes, which catalyses the conversion of fatty acyl-CoA to the corresponding alcohols. Among the FAR family members in the brown planthopper (Nilaparvata lugens), NlFAR7 plays a pivotal role in both the synthesis of cuticular hydrocarbons and the waterproofing of the cuticle. However, the precise mechanism by which NlFAR7 influences the formation of the cuticle structure in N. lugens remains unclear. Therefore, this paper aims to investigate the impact of NlFAR7 through RNA interference, transmission electron microscope, focused ion beam scanning electron microscopy (FIB-SEM) and lipidomics analysis. FIB-SEM is employed to reconstruct the three-dimensional (3D) architecture of the pore canals and related cuticle structures in N. lugens subjected to dsNlFAR7 and dsGFP treatments, enabling a comprehensive assessment of changes in the cuticle structures. The results reveal a reduction in the thickness of the cuticle and disruptions in the spiral structure of pore canals, accompanied by widened base and middle diameters. Furthermore, the lipidomics comparison analysis between dsNlFAR7- and dsGFP-treated N. lugens demonstrated that there were 25 metabolites involved in cuticular lipid layer synthesis, including 7 triacylglycerols (TGs), 5 phosphatidylcholines (PCs), 3 phosphatidylethanolamines (PEs) and 2 diacylglycerols (DGs) decreased, and 4 triacylglycerols (TGs) and 4 PEs increased. In conclusion, silencing NlFAR7 disrupts the synthesis of overall lipids and destroys the cuticular pore canals and related structures, thereby disrupting the secretion of cuticular lipids, thus affecting the cuticular waterproofing of N. lugens. These findings give significant attention with reference to further biochemical researches on the substrate specificity of FAR protein, and the molecular regulation mechanisms during N. lugens life cycle.

Error-Triggered Adaptive Sparse Identification for Predictive Control and Its Application to Multiple Operating Conditions Processes.

With the digital transformation of process manufacturing, identifying the system model from process data and then applying to predictive control has become the most dominant approach in process control. However, the controlled plant often operates under changing operating conditions. What is more, there are often unknown operating conditions such as first appearance operating conditions, which make traditional predictive control methods based on identified model difficult to adapt to changing operating conditions. Moreover, the control accuracy is low during operating condition switching. To solve these problems, this article proposes an error-triggered adaptive sparse identification for predictive control (ETASI4PC) method. Specifically, an initial model is established based on sparse identification. Then, a prediction error-triggered mechanism is proposed to monitor operating condition changes in real time. Next, the previously identified model is updated with the fewest modifications by identifying parameter change, structural change, and combination of changes in the dynamical equations, thus achieving precise control to multiple operating conditions. Considering the problem of low control accuracy during the operating condition switching, a novel elastic feedback correction strategy is proposed to significantly improve the control accuracy in the transition period and ensure accurate control under full operating conditions. To verify the superiority of the proposed method, a numerical simulation case and a continuous stirred tank reactor (CSTR) case are designed. Compared with some state-of-the-art methods, the proposed method can rapidly adapt to frequent changes in operating conditions, and it can achieve real-time control effects even for unknown operating conditions such as first appearance operating conditions.

Parallel Fractional Stochastic Gradient Descent With Adaptive Learning for Recommender Systems

The structural change toward the digital transformation of online sales elevates the importance of parallel processing techniques in recommender systems, particularly in the pandemic and post-pandemic era. Matrix factorization (MF) is a popular and scalable approach in collaborative filtering (CF) to predict user preferences in recommender systems. Researchers apply Stochastic Gradient Descent (SGD) as one of the most famous optimization techniques for MF. Paralleling SGD methods help address Big Data challenges due to the wide range of products and the sparsity in user ratings. However, these methods’ convergence rate and accuracy are affected by the dependency between the user and item latent factors, specifically in large-scale problems. Besides, the performance is sensitive to the applied learning rates. This paper proposes a new parallel method to remove dependencies and boost speed-up by using fractional calculus to improve accuracy and convergence rate. We also apply adaptive learning rates to enhance the performance of our proposed method. The proposed method is based on Compute Unified Device Architecture (CUDA) platform. We evaluate the performance of our proposed method using real-world data and compare the results with the close baselines. The results show that our method can obtain high accuracy and convergence rate in addition to high parallelism.

Numerical modeling of structural body deformation under free surface flow based on volume of fluid–discrete element method coupling

In this work, we proposed a numerical model based on the coupling of the volume of fluid–discrete element method and bond particle method (BPM). The simulation of particle bonding and the structural body formation process had been presented, and the inter-particle bonding mechanism was introduced. We also tested dam-busting impact elastic and wedge plates at high Reynolds numbers (1.26 × 107 and 2.16 × 106) and compared the results with numerical simulations. The results show that the model has mean errors of 3.9% and 6.5% for the large and the micro-deformations, respectively. It is in perfect agreement with the curve trends of the test and keeps good convergence for different particle sizes. In addition, we also used the model used to study the hydrodynamic changes in underwater box net structures in offshore aquaculture, and the deformation kinematic properties of box nets under different material strengths were evaluated. This numerical model of this study provides the effective theoretical support and engineering guidance for the further study of the behavior of structural bodies under hydrodynamic action.

Posttreatment Head and Neck Cancer Imaging: Anatomic Considerations Based on Cancer Subsites.

Posttreatment imaging surveillance of head and neck cancer is challenging owing to complex anatomic subsites and diverse treatment modalities. Early detection of residual disease or recurrence through surveillance imaging is crucial for devising optimal treatment strategies. Posttreatment imaging surveillance is performed using CT, fluorine 18-fluorodeoxyglucose PET/CT, and MRI. Radiologists should be familiar with postoperative imaging findings that can vary depending on surgical procedures and reconstruction methods that are used, which is dictated by the primary subsite and extent of the tumor. Morphologic changes in normal structures or denervation of muscles within the musculocutaneous flap may mimic recurrent tumors. Recurrence is more likely to occur at the resection margin, margin of the reconstructed flap, and deep sites that are difficult to access surgically. Radiation therapy also has a varying dose distribution depending on the primary site, resulting in various posttreatment changes. Normal tissues are affected by radiation, with edema and inflammation occurring in the early stages and fibrosis in the late stages. Distinguishing scar tissue from residual tumor becomes necessary, as radiation therapy may leave behind residual scar tissue. Local recurrence should be carefully evaluated within areas where these postradiation changes occur. Head and Neck Imaging Reporting and Data System (NI-RADS) is a standardized reporting and risk classification system with guidance for subsequent management. Familiarity with NI-RADS has implications for establishing surveillance protocols, interpreting posttreatment images, and management decisions. Knowledge of posttreatment imaging characteristics of each subsite of head and neck cancers and the areas prone to recurrence empowers radiologists to detect recurrences at early stages. ©RSNA, 2024 Test Your Knowledge questions in the supplemental material and the slide presentation from the RSNA Annual Meeting are available for this article.

Implicit Bias versus Intentional Belief: When Morally Elevated Leadership Drives Transformational Change

Abstract The twenty-first century is witnessing rapid and deep change in the global economy. These changes require innovation-driven solutions and motivated, skilled workforces. The talents of every person will be required to support performance in every domain, and deliberate actions must be taken to address impediments to full engagement. Even with clear government policy and significant investments in encouraging representation and inclusion of diversity of race, sexual orientation, gender identity, and ability, progress continues to lag. This essay captures promising practices and recommendations for structural or systemic change punctuated with stories of leadership driven by the belief that implementing strategies to disrupt the effects of implicit bias are important to develop diverse, fully engaged populations.

The Asymmetric Relationship between Conventional/Shale Rig Counts and WTI Oil Prices

This work analyses the asymmetric response of conventional and shale oil rig counts to WTI oil price returns. Our analysis shows that the rig count time series exhibited a structural change after the oil glut of 2014. All series are non-stationary in each sub-period but not cointegrated. Therefore, after controlling for possible confounding factors, a vector auto regressive (VAR) model is set up. Our specification accounts for the possible role of oil production and distinguishes between positive and negative oil price changes. It is shown that shale and conventional rig counts reacted differently in each subperiod to signed changes in oil price. Subsequently, by evaluating the response of rig counts to oil price shocks, their intensity and duration over time, we observe that the shale oil rig count reacts more intensively to positive than to negative oil price changes. On the contrary, the conventional rig count exhibits a modest reaction only to positive price changes. Finally, we robustify our findings by focusing on the data of the Permian basin, on the one hand, and the Anadarko, Bakken, Eagle Ford and Niobrara, on the other hand, which are characterized by different patterns in the number of Drilled but not Completed wells.

أثر إدارة التغيير على التحول الرقمي في قطاع الاتصالات في اليمن

The objective of this study is to determine the impact of change management on digital transformation initiatives in Yemeni telecom sector. A quantitative approach with analytical and deductive methods was adopted to examine the relationship and determine impact between change management and digital transformation. The study targeted a population of 902 managers and team leaders in the sector. A questionnaire was developed and distributed to a stratified sample of 226 respondents. The random sample was 25% of each stratum. Questionnaire items were designed to measure the change management dimensions (Change Urgency, Visionary Coalition, Empowerment and Sustainability) and digital transformation dimensions (Technology, Processes, People, Culture and Business Model). The results generated show a highly significant positive relationship between effective change Management practices and the successful implementation of digital transformation initiatives (substantial positive coefficient B of 0.786, R2 of 0.62 and high t-value of 29.34, and the extremely low p-value below 0.001). In conclusion, this study indicates that digital transformation initiatives require practicing proper and structural change management practices.

David versus Goliath: Early career researchers in an unethical publishing system.

The publish-or-perish culture in academia has catalysed the development of an unethical publishing system. This system is characterised by the proliferation of journals and publishers-unaffiliated with learned societies or universities-that maintain extremely large revenues and profit margins diverting funds away from the academic community. Early career researchers (ECRs) are particularly vulnerable to the consequences of this publishing system because of intersecting factors, including pressure to pursue high impact publications, rising publication costs and job insecurity. Moving towards a more ethical system requires that scientists advocate for structural change by making career choices that come with risks, many of which disproportionately impact ECRs. We illuminate major issues facing ECRs in Ecology and Evolution under the current publishing system, and propose a portfolio of actions to promote systemic change that can be implemented by ECRs and established researchers.

Analysis of Imbalance Price Fluctuating Factors Considering Price Structural Change

Analysis of Imbalance Price Fluctuating Factors Considering Price Structural Change

Evaluation of changes in macular structures after subthreshold micropulse laser therapy on chronic central serous chorioretinopathy.

To evaluate the changes in macular structures following subthreshold micropulse laser (SHML) treatment for chronic central serous chorioretinopathy (cCSC). Data of 33 eyes from 31 cCSC patients treated with SHML and followed up for at least 6 months has been included in this retrospective study. Main outcome measurements include resolution of subretinal fluid (SRF) and pigment epithelial detachment (PED), the recovery of ellipsoid zone (EZ) continuity, and the foveal outer nuclear layer (ONL) thickness along with its ratio. Mean observation period is 7.355 months (ranging from 6 to 24 months) and mean number of treatments administered is 1.839 (ranging from 1 to 5). 6 months after SHML treatment, there is a significant decrease in the area of SRF and PED (P < 0.001, P = 0.010, respectively). Additionally, the frequency of continuous EZ and the foveal ONL thickness reveal a significant increase (P<0.001, P = 0.005, respectively). The ratio of foveal ONL thickness is significantly higher after laser treatment, particularly in patients with a disease duration of ≤12 months (p = 0.022, P=0.036, respectively). SHML treatment proves to be effective in cCSC eyes, leading to satisfactory recovery of macular structures, especially the photoreceptor layer.

A Post-COVID Inflection Point and Call to Action: Theorizing a Legal Right to Youth Sport, Play, and Physical Activity in the United States

Literature links sport, play, and similar leisure endeavors to numerous physical, psychological, and social benefits critical to a young person’s development. Unlike other nations, the United States lacks a national policy to fund structures supporting youth sport, play, and the like. Instead, a for-profit youth sport industry oversees this sector using a pay-to-play model, creating significant financial and access barriers. The COVID-19 pandemic created an inflection point and call for action to meaningfully reform youth sport. Advocates often claim, without providing legal justification, that access to sport and play is a constitutional right. Therefore, the purpose of this commentary is to move beyond aspiration or hypothetical rhetoric and investigate whether a persuasive legal argument exists that places a constitutional legal responsibility upon the United States federal government to create structures, allocate funding, and provide universal access to free sport, recreation, and play opportunities for youth. While review and analysis of relevant case law found that no constitutional right likely existed under United States law, this process confirmed that that such claims will have little chance of success under current precedent. Therefore, given the improbability of substantive voluntary reforms in the private sector, a deeper exploration of innovative legal theories is required to achieve the necessary structural change.

Occlusion and Nutrition after Peadiatric Prosthetic Treatment

Nutritional and well-balanced food intake is of utmost importance for children's proper physical development and growth. Changes in masticatory structures are likely to cause significant change in both children's and adult's diet. The aim of this study is to examine the occlusion and the intake of macronutrients in children who have undergone dental treatment and restoration of the teeth affected by caries and its complications with different types of aesthetic crowns.&#x0D; The study included 103 children, which are prosthetically treated with crown structures and divided into four age groups. The restoration of the occlusal balance after the completion of the prosthetic treatment was established by means of a new generation of digital recording system (OccluSense by Bausch, Germany). A 24-hour diary on consumed foods and liquids was taken from children and their parents. Data is analyzed and processed statistically.&#x0D; The obtained results in all studied diagrams showed an increase in the occlusal forces bilaterally in the distal areas of the dentition in the anterior-posterior direction. Protein and carbohydrate intake by the tested children corresponded to the recommended range of 15.2±3.7 E% and 46.6±7.8 E%. Increased fat intake of 38.1±7.5 E%, as well as fibre consumption below the recommended values (13.6 g to 18.6 g) have also been observed.&#x0D; Dental restoration of heavily damaged children's teeth using prosthetic dentistry methods provides the opportunity for a normal intake of the main macronutrients.

Assessment of the structural change of DNA by binding with a small molecule based on capillary sieving electrophoresis.

In this study, capillary sieving electrophoresis (CSE) using polymer solutions was used to evaluate the structural changes in nucleic acids upon complexation with small molecules. As the model target and nucleic acids, L-tyrosinamide (Tyr-Am) and its aptamer, which is a type of DNA specifically binding to Tyr-Am, were selected. CSE was conducted using a capillary filled with background solution (BGS) containing hydroxypropyl cellulose (HPC) as a sieving matrix. When Tyr-Am or tyrosine was added to the BGS in CSE, the ratio of mobility differences of the Tyr-Am-aptamer complex increased compared to that of the free aptamer without the addition of Tyr-Am. In contrast, when other amino acids or their analogs were added, results showed no apparent change or decreases in electrophoretic mobility. These results indicate that the proposed method can be applied to assess structural changes in nucleic acids that target small molecules.

‘라이즈’ 도입과 광주광역시 고등교육의 현황, 문제, 대안

If higher education jurisdiction is partially delegated/transferred to local governments according to the Regional Innovation System and Education (RISE), which is scheduled to be introduced in 2025, Korea's higher education system will experience structural changes. The core content of structural change is the dualization of guidance/supervision authority for higher education institutions. The central government and local governments jointly govern higher education. The purpose of this paper is to discuss win-win cooperation measures between Gwangju City and universities in response to the ‘RISE’. To achieve the purpose of this paper, three topics were intensively discussed based on literature analysis. First, in order to understand the relationship between local governments and universities, the relationship between the two was identified and the meaning of win-win cooperation was critically discussed. Second, in order to understand the current status of higher education in Gwangju city, the reality of higher education in Gwangju was analyzed at the national/regional level, focusing on key indicators. Third, in the problems and alternatives of Gwangju higher education, key problems were pointed out and alternatives were presented based on the four factors that make up the higher education system (purpose structure, governance structure, financial structure, and performance management). In the conclusion, it was emphasized that public value should be emphasized in the direction of innovation in the higher education system at the national/regional level and a special change in perception in local governments' understanding of universities was emphasized.