Critical Spot Research Articles

Dynamic stress prediction for a Pump-Turbine in Low-Load Conditions: Experimental validation and phenomenological analysis

To meet the increasing demand for higher flexibility in hydropower, an operating range extension in an existing hydroelectric powerplant is considered. To this end, the dynamic flow and structural behavior of the low-head pump-turbine is investigated in turbine mode in partial load and deep partial load conditions, to evaluate the feasibility of this flexibilization due to the increased high cycle fatigue damage. In a first step, different numerical simulation approaches that combine fluid dynamics and structural dynamics are applied and compared to in-situ dynamic strain and pressure measurements on the impeller. As a result, the modelling requirements for a numerical workflow that leads to unmatched accuracy in predicting the broad-band dynamic stresses of deep partial load are identified. In a second step, the operating-point-dependent fatigue crack initiation spots are identified based on dynamic stresses. Herein, the emergence of an additional dominant critical spot near the blade leading edge is observed, which is unexpected for low-head pump turbines. Thanks to the detailed numerical flow and structural analyses, the root cause for the dynamic stress concentration is studied and the emergence of the new critical spot is understood. It turns out in deep partial load, that the main source of pressure oscillations on the impeller blade surfaces is the vortex-dominated flow detachment zone around the blade leading edge, which, in combination with the geometry of the investigated impeller, translates into the main stress oscillations. The results of this work were later used to extend the operating range of the hydroelectric powerplant from initially 25% to 100% power output to now 0% to 100%.

제국의 역습

Edgar Allan Poe’s “Ligeia” has been an object of scholarly attention ever since D. H. Lawrence’s ground-breaking reading of it as a ‘vampire story’ in Studies in Classic American Literature. That attention has one critical blind spot to it, which is the lack of consideration on one of the story’s three main characters: Rowena. This paper proposes giving her a chance to be examined as yet another vampiric figure along with the narrator and Ligeia, on account of the symbiotically interdependent relationship between the vampire and the victim. The paper parallels this relationship with the complex interaction between the US and England in the 19th century, which revolves around a paradox of the former’s attempt to liberate itself from the latter’s imperial dominion while aspiring to be a new empire like the latter. The paper posits the narrator and Rowena as the US and England, respectively, and traces their struggle to take over the origin of Western imperialism which is embodied in Ligeia and to perpetuate its legacy. The ultimate goal of this paper is to show “Ligeia” as a story of Poe’s questioning the US’s unquestioning pursuit of global imperialism, thereby proving its resonance for our own time.

Lizzie’s Insistent Rejection to Her Unconscious Desires in Christina Rossetti’s Goblin Market through the Lens of Lacanian Desires

The growing concern in the latest critical practices and processes of a great many scholars as indicated in the continuous development and improvement of literary criticism with respect to the veritable and valuable characterization of this poem Goblin Market (1862) has been shown for the essential and evident exploration of the feasible solutions to the problems as most women character have to be faced with in an unavoidable fashion in Victorian age due to their blind adaptation to the ideological and epistemological values emphasized in the continuation of Christian beliefs regarding the essential and crucial morality to be followed in the increasing enrichment and improvement of their rationalist mentality. However, it has seemed to be quite pitiful that they have failed to probe into the unconscious minds of the vivid characters depicted in this poem to lay an ideological and epistemological foundation for the apparent clarification of the strong will of this character Lizzie has developed to enable her to get free from the imprisonment or enslavement of the hegemonic desires carried in the harmful fruits of the goblin men she and her sister Laura has encountered in their lives. For the sake of this critical blind spot, this paper will explore Lizzie’s strong will used to protect the purity and piety of her unconscious desires and to reduce to the least the possibility for her to fall victim to the vicious desires those goblin men aim to impress and impose upon her mind indebted to the rich theoretical enlightenment and encouragement entailed in Lacanian desires related to the conceptual elaboration of the longing for wholeness, sanity, and, meaning in the rich lives of his analysands. In the long run, this exploration will remind more and more readers of the objective truth that the strong willingness of women as exemplified in what has happened to Lizzie is bound to give rise to their great successes in rejecting their unconscious desires triggered in the popularization of the vicious desires of polluted men like those of the goblin men in this poem as epitomized in the developmental inclined with which the marketization and capitalization of the communicative activities related to the commercialization and commodification of the harmful and sinful fruits peddled in goblin market.

A Study Of Emotional And Cultural Longing Of India In Jhumpa Lahiri’s Interpreter Of Maladies

Indian diasporic writings made its milestone passage with the works of Salman Rushdie, Bharati Mukherjee, Jhumpa Lahiri, Amitav Ghosh, Rohinton Mistry, and Vikram Seth who earned popularity while dwelling abroad. One of the significant parts of these writers is that they compose transcendently the encounters of displacement. They have given more strength to the exploration with a geological disengagement but additionally a diasporic consciousness towards their home nation. Jhumpa Lahiri is one of the renowned writers of the Indian Diaspora. She possesses a critical spot in world writing. Her works manage the subjects of migration, uprooting, loss of personality, conflict of societies, profound edifices, human relations, and correspondence hindrances. In the current paper, four brief tales from the collection Interpreter of Maladies (1999) are considered for examining her sensibility towards India and Indianness. The meaning of the work as a diasporic brief tale collection lies unequivocally in the writer's endeavor to take advantage of the basic pressure when one lives between two universes and two societies.

Changes in Older Adult Trauma Quality When Evaluated Using Longer-Term Outcomes vs In-Hospital Mortality

Lack of knowledge about longer-term outcomes remains a critical blind spot for trauma systems. Recent efforts have expanded trauma quality evaluation to include a broader array of postdischarge quality metrics. It remains unknown how such quality metrics should be used. To examine the utility of implementing recommended postdischarge quality metrics as a composite score and ascertain how composite score performance compares with that of in-hospital mortality for evaluating associations with hospital-level factors. This national hospital-level quality assessment evaluated hospital-level care quality using 100% Medicare fee-for-service claims of older adults (aged ≥65 years) hospitalized with primary diagnoses of trauma, hip fracture, and severe traumatic brain injury (TBI) between January 1, 2014, and December 31, 2015. Hospitals with annual volumes encompassing 10 or more of each diagnosis were included. The data analysis was performed between January 1, 2021, and December 31, 2022. Reliability-adjusted quality metrics used to calculate composite scores included hospital-specific performance on mortality, readmission, and patients' average number of healthy days at home (HDAH) within 30, 90, and 365 days among older adults hospitalized with all forms of trauma, hip fracture, and severe TBI. Associations with hospital-level factors were compared using volume-weighted multivariable logistic regression. A total of 573 554 older adults (mean [SD] age, 83.1 [8.3] years; 64.8% female; 35.2% male) from 1234 hospitals were included. All 27 reliability-adjusted postdischarge quality metrics significantly contributed to the composite score. The most important drivers were 30- and 90-day readmission, patients' average number of HDAH within 365 days, and 365-day mortality among all trauma patients. Associations with hospital-level factors revealed predominantly anticipated trends when older adult trauma quality was evaluated using composite scores (eg, worst performance was associated with decreased older adult trauma volume [odds ratio, 0.89; 95% CI, 0.88-0.90]). Results for in-hospital mortality showed inverted associations for each considered hospital-level factor and suggested that compared with nontrauma centers, level 1 trauma centers had a 17 times higher risk-adjusted odds of worst (highest quantile) vs best (lowest quintile) performance (odds ratio, 17.08; 95% CI, 16.17-18.05). The study results challenge historical notions about the adequacy of in-hospital mortality as the single measure of older adult trauma quality and suggest that, when it comes to older adults, decisions about how quality is evaluated can profoundly alter understandings of what constitutes best practices for care. Composite scores appear to offer a promising means by which postdischarge quality metrics could be used.

Thermal Analysis and In-Field Critical Current Estimation of Conduction-Cooled REBCO Magnet Considering Nonuniform Temperature Distribution

Due to the high upper critical field and transition temperature, REBCO coated conductor show great promise for conduction-cooled magnet applications. The normal zone of high temperature conductor (HTS) spreads slowly, and the conversion of a weak spot into a hot spot is localized and quite fast. Hence, in-field critical current weak spot evaluation under the nonuniform temperature gradient is important for conduction-cooled magnet stability estimation. Cooling path design needs to take the weak spot into account. In this study, a temperature-field-angle dependent critical current estimation neural network was first trained based on a public database of HTS critical current. The equivalent thermal conductivity was applied for the interface contact between the turns. Thermal contact conditions were given to the interface between the coil and bobbin considering actual production situations, such as thermal grease. Combing the non-uniform magnetic field and thermal distribution, the critical current distribution was evaluated to track the weak part. The results of this study will be employed in the design analysis of high magnetic field conduction cooling magnets in the future.

EADD-YOLO: An efficient and accurate disease detector for apple leaf using improved lightweight YOLOv5.

Current detection methods for apple leaf diseases still suffer some challenges, such as the high number of parameters, low detection speed and poor detection performance for small dense spots, which limit the practical applications in agriculture. Therefore, an efficient and accurate model for apple leaf disease detection based on YOLOv5 is proposed and named EADD-YOLO. In the EADD-YOLO, the lightweight shufflenet inverted residual module is utilized to reconstruct the backbone network, and an efficient feature learning module designed through depthwise convolution is proposed and introduced to the neck network. The aim is to reduce the number of parameters and floating point of operations (FLOPs) during feature extraction and feature fusion, thus increasing the operational efficiency of the network with less impact on detection performance. In addition, the coordinate attention module is embedded into the critical locations of the network to select the critical spot information and suppress useless information, which is to enhance the detection accuracy of diseases with various sizes from different scenes. Furthermore, the SIoU loss replaces CIoU loss as the bounding box regression loss function to improve the accuracy of prediction box localization. The experimental results indicate that the proposed method can achieve the detection performance of 95.5% on the mean average precision and a speed of 625 frames per second (FPS) on the apple leaf disease dataset (ALDD). Compared to the latest research method on the ALDD, the detection accuracy and speed of the proposed method were improved by 12.3% and 596 FPS, respectively. In addition, the parameter quantity and FLOPs of the proposed method were much less than other relevant popular algorithms. In summary, the proposed method not only has a satisfactory detection effect, but also has fewer parameters and high calculation efficiency compared with the existing approaches. Therefore, the proposed method provides a high-performance solution for the early diagnosis of apple leaf disease and can be applied in agricultural robots. The code repository is open-sourced at https://github.com/AWANWY/EADD-YOLO.

Solvent Effects Enable Efficient Tandem Conversion of Cellulose and Its Monosaccharides Towards 5-Hydroxymethylfurfural.

The biomass-derived platform compound 5-hydroxymethylfurfural (HMF) has been hailed as the "Sleeping Giant" due to its promising applications, and it occupies a critical spot in the biomass upgrading roadmap. HMF is typically produced from cellulose and its monosaccharides via a complex tandem conversion with multiple steps (i. e., cellulose depolymerization, glucose isomerization, fructose dehydration, etc.). Previous investigations have confirmed the irreplaceable contribution of solvents in regulating the tandem conversion of cellulose and its monosaccharides to HMF. However, the potential effects of solvents in contributing to this multi-step tandem process have not yet been clearly elucidated. In this context, this Review aims to provide in-depth insights into the intrinsic interactions between solvent system and substrate conversion (cellulose and its monosaccharides conversion), reaction regulation (reaction activity and selectivity regulation), as well as product acquisition (humins formation inhibition and product purification). It attempts to elucidate specific solvent effects to promote a more efficient tandem conversion of cellulose and its monosaccharides towards HMF. The insights provided in this Review may contribute to a more sustainable HMF production from biomass feedstocks and a further development of greener solvent systems.

Embedded systems and printed circuit boards as weak spots in HV-H3TRB tests

Wide-band-gap (WBG) devices and embedding technology offer a huge advantage when increasing the power density of power electronics. However, the miniaturisation leads to new reliability challenges. The critical spot prone to humidity degradation moves outside the actual device under test (DUT) to the periphery, i.e. printed circuit board assemblies (PCBA). In the case of High Voltage Embedding Technology (HVET) devices, the housing of the power element is completely omitted. The materials used in HVET must entirely ensure the moisture protection of the power unit and the passive components of the embedded systems.In this work, results on various batches of PCBA and HVET after several thousand hours of testing in High Voltage-High Humidity High Temperature Reverse Bias (HV-H3TRB) are presented. Failure analyses have identified degradation mechanisms such as conductive anodic filament (CAF) formed inside the FR-4 printed circuit boards (PCB) and anodic migration phenomenon (AMP) in HVET devices as the root cause of failures. Therefore, special preventive procedures are required in harsh climatic conditions.

Dynamic effects of temperature-dependent aberration factors on the beam quality of LD end-pumped lasers

Considering the temperature dependence of the thermal conductivity of the gain medium, the aberration factor of the thermal lens becomes a function of temperature. The influence of the aberration factor on critical spot size is analyzed, the actual value of critical spot size is recalculated, and the range of beam quality deterioration is re-pointed. An asymmetric flat cavity experiment is built, and a symmetrical flat cavity is used as the supporting experiment. The widened beam quality degradation range and the dynamic operating point of the fundamental mode beam are pointed out. Experimental results match the simulation.

Risky Decision Making Under Stressful Conditions: Men and Women With Smaller Cortisol Elevations Make Riskier Social and Economic Decisions.

Men often make riskier decisions than women across a wide range of real-life behaviors. Whether this sex difference is accentuated, diminished, or stable under stressful conditions is, however, contested in the scientific literature. A critical blind spot lies amid this contestation: Most studies use standardized, laboratory-based, cognitive measures of decision making rather than complex real-life social simulation tasks to assess risk-related behavior. To address this blind spot, we investigated the effects of acute psychosocial stress on risk decision making in men and women (N = 80) using a standardized cognitive measure (the Iowa Gambling Task; IGT) and a novel task that simulated a real-life social situation (an online chatroom in which participants interacted with other men and women in sexually suggestive scenarios). Participants were exposed to either an acute psychosocial stressor or an equivalent control condition. Stressor-exposed participants were further characterized as high- or low-cortisol responders. Results confirmed that the experimental manipulation was effective. On the IGT, participants characterized as low-cortisol responders (as well as those in the Non-Stress group) made significantly riskier decisions than those characterized as high-cortisol responders. Similarly, in the online chatroom, participants characterized as low-cortisol responders (but not those characterized as high-cortisol responders) were, relative to those in the Non-Stress group, significantly more likely to make risky decisions. Together, these results suggest that at lower levels of cortisol both men and women tend to make riskier decisions in both economic and social spheres.

Identification and distribution of pathogens coinfecting with Brucella spp., Coxiella burnetii and Rift Valley fever virus in humans, livestock and wildlife.

SummaryZoonotic diseases, such as brucellosis, Q fever and Rift Valley fever (RVF) caused by Brucella spp., Coxiella burnetii and RVF virus, respectively, can have devastating effects on human, livestock, and wildlife health and cause economic hardship due to morbidity and mortality in livestock. Coinfection with multiple pathogens can lead to more severe disease outcomes and altered transmission dynamics. These three pathogens can alter host immune responses likely leading to increased morbidity, mortality and pathogen transmission during coinfection. Developing countries, such as those commonly afflicted by outbreaks of brucellosis, Q fever and RVF, have high disease burden and thus common coinfections. A literature survey provided information on case reports and studies investigating coinfections involving the three focal diseases. Fifty five studies were collected demonstrating coinfections of Brucella spp., C. burnetii or RVFV with 50 different pathogens, of which 64% were zoonotic. While the literature search criteria involved ‘coinfection’, only 24/55 studies showed coinfections with direct pathogen detection methods (microbiology, PCR and antigen test), while the rest only reported detection of antibodies against multiple pathogens, which only indicate a history of co‐exposure, not concurrent infection. These studies lack the ability to test whether coinfection leads to changes in morbidity, mortality or transmission dynamics. We describe considerations and methods for identifying ongoing coinfections to address this critical blind spot in disease risk management.

THE CONCEPTUAL FRAMEWORK OF STUDY TO ANALYZE THE STATUS OF WOMEN IN PAKISTANI FAMILY SYSTEM

In prior times, women were oppressed and abused by way of every attainable method in societies. They endured lots of critique, needed opportunity and stood no place close to men. They were denied of the essential inheritances of an individual. It required lots of exertion and boldness for them to stamp an impression of "the potential and capability of women" and make a critical spot in the community. The objective of this research paper was to analyze the status of women in Pakistan in other word status provided to women in Pakistani family structure and also to analyze its status in Islamic. For the results secondary data was collected from books, research papers, journals and different reports. It was found that women facing violence at various stages in their life in Pakistan. This adversely influences the character/traits of women, harms mental and actual wellbeing and obliterates creativity and efficiency of their endeavors. Low proficiency pace of women, absence of clinical facilities in various areas and no kind of revenue for family women is in problem with women. Here regarding women status, the teaching of Islamic is neglected. It was concluded that, With regards to Pakistan, the indispensable issue is that our religion Islamic has not had the option to cancel the exceptionally old un-Islamic and furthermore cruel social indecencies that are being exercised in the land. Hence, ancestral, family, tribal imagery has gotten more prevailing and helpful than the confidence of Islamic. So it was recommended that the government should maintain the status of women according to teaching of Islamic.

Effects of surface wettability on pool boiling process: Dynamic and thermal behaviors of dry spots and relevant critical heat flux triggering mechanism

In this paper, we investigate experimentally and numerically the influences of surface wettability on the boiling process from nucleate boiling to critical heat flux (CHF). The boiling surfaces with four different wettabilities (apparent contact angles) are examined. Using a simple optic setup, sequential phase distribution images on the boiling surfaces were acquired, and we analyzed the dynamics of microlayer, bulk liquid region, and dry spots with the processed images. The variation of surface wettability significantly affected the liquid and vapor phase behaviors on the boiling surface, such as the growth and shrinkage of the microlayer and dry spot, wetting velocity and area portion of the dry spot. As a result, the CHF increased with the surface wettability, and we found the CHF is triggered from a local dry spot where the liquid wets the spot no longer and is violently scattered by strong evaporation at the triple contact line. Our numerical simulation results, in which the three-dimensional transient heat diffusion equation was solved for the boiling substrate using the phase distribution images as boundary conditions, indicated that certain dry spots (critical dry spot) can be highly overheated under high heat flux condition, and they lead significant heat transfer degradation and, eventually, the CHF. With the numerical results and observation of the phase distribution images at the CHF conditions, we postulated the allowable wetting temperature and formulated it as a function of surface wettability through considering the balance between vapor recoil and surface tension forces. The wetting temperature increased with surface wettability, and it was confirmed by the numerical results. Finally, we proposed a qualitative relation to elucidate the influence of surface wettability on the CHF based on the heat conduction via the vapor on a critical dry spot and heat flux partitioning concept.

Are All Purposes Worth Having? Integrating Content and Strength in Purpose Research

A prevailing belief is that a sense of purpose in life is worth having, based on evidence that it predicts greater psychological functioning, social relationships, physical health, and longevity. Yet, whether the benefits of having a sense of purpose persist across all contents – or the actual substance of one’s aspirations – lingers as a critical blind spot within this literature. Here, we contend that an ecological systems perspective is needed to contextualize how purpose content either enables or extinguishes the benefits of feeling purposeful. We nominate congruence (the fit between a purpose and ecological conditions) and feasibility (the ease with which a purpose can be pursued) as measurable features of purpose content that fuse people and contexts and potentiate whether a sense of purpose proves favorable. Greater congruence and feasibility should orchestrate support for purpose-related goals, actions, and justifications, thus amplifying the likelihood of positive outcomes. Practical strategies for integrating the congruence and feasibility of individuals’ aspirations within the study of purpose are discussed.

Mimetic Presuppositions: On the Epitextual Responses to Two Poems in English by Marlene van Niekerk

Summary In this article, I consider two fairly recent English poems by Marlene van Niekerk: “Mud school” (2013) and “Fallist art (in memory of Bongani Mayosi)” (2018). Specifically, I explore the context surrounding the production of these poems, and what we can possibly glean from their limited (and not exclusively literary) reception in order to understand how this part of Van Niekerk’s (English) authorship has thus far been read in more limited ways by critics and scholars. By focusing on the epitextual responses surrounding these poems, I show how they are symptomatic of what Jahan Ramazani calls the “mimetic presuppositions” that often take shape in critical readings of postcolonial literature (2004). Considering the especially politically engaged nature of Van Niekerk’s novels in particular, I argue that the oversight of Van Niekerk’s poetry, both residing in the dearth of translation of her poetry and in the critical blind spot writ large in studies of her work in English, comes as a result of what Emma Bird (2018) calls poetry’s “distinctly peripheral position” in postcolonial literary studies – a critical lens that has in various ways directed readings of Van Niekerk’s English work.

A Soft Pressure Sensor Skin to Predict Contact Pressure Limit Under Hand Orthosis.

Customized static orthoses in rehabilitation clinics often cause side effects, such as discomfort and skin damage due to excessive local contact pressure. Currently, clinicians adjust orthoses to reduce high contact pressure based on subjective feedback from patients. However, the adjustment is inefficient and prone to variability due to the unknown contact pressure distribution as well as differences in discomfort due to pressure across patients. This paper proposed a new method to predict a threshold of contact pressure (pressure limit) associated with moderate discomfort at each critical spot under hand orthoses. A new pressure sensor skin with 13 sensing units was configured from FEA results of pressure distribution simulated with hand geometry data of six healthy participants. It was used to measure contact pressure under two types of customized orthoses for 40 patients with bone fractures. Their subjective perception of discomfort was also measured using a 6 scores discomfort scale. Based on these data, five critical spots were identified that correspond to high discomfort scores (>1) or high pressure magnitudes (>0.024 MPa). An artificial neural network was trained to predict contact pressure at each critical spot with orthosis type, gender, height, weight, discomfort scores and pressure measurements as input variables. The neural networks show satisfactory prediction accuracy with R2 values over 0.81 of regression between network outputs and measurements. This new method predicts a set of pressure limits at critical locations under the orthosis that the clinicians can use to make orthosis adjustment decisions.

A GRU deep learning system against attacks in software defined networks

The management of modern network environments is becoming more and more complex due to new requirements of devices' heterogeneity regarding the popularization of the Internet of Things (IoT), as well as the dynamic traffic required by next-generation applications and services. To address this problem, Software-defined Networking (SDN) emerges as a management paradigm able to handle these problems through a centralized high-level network approach. However, this centralized characteristic also creates a critical failure spot since the central controller may be targeted by malicious users aiming to impair the network operation. This paper proposes an SDN defense system based on the analysis of single IP flow records, which uses the Gated Recurrent Units (GRU) deep learning method to detect DDoS and intrusion attacks. This direct flow inspection enables faster mitigation responses, minimizing the attack's impact over the SDN. The proposed model is tested against several different machine learning approaches over two public datasets, the CICDDoS 2019 and the CICIDS 2018. Furthermore, a lightweight mitigation approach is presented and evaluated through performance tests regarding each detection method. Finally, a feasibility test is performed regarding the throughput of flows per second that each detection method can analyze. This test is accomplished through the use of real IP Flow data collected at a large-scale network. The results point out promising detection rates and an elevated amount of analyzed flows per second, which makes GRU a feasible approach for the proposed system.

Cooling for sustainable development

The unprecedented rise in cooling demand globally is a critical blind spot in sustainability debates. We examine cooling as a system comprised of active and passive measures, with key social and technical components, and explain its link to all 17 Sustainable Development Goals. We propose an analytical and solution-oriented framework to identify and shape interventions towards sustainable cooling. The framework comprehends demand drivers; cradle-to-cradle stages; and system change levers. By intersecting cooling stages and levers, we discuss four specific, exemplary interventions to deliver sustainable cooling. We propose an agenda for research and practice to transition towards sustainable cooling for all.

Jak na kritická místa ve výuce zeměpisu?

This paper presents results of our research on critical spots in geography education. Critical spots and their causes were identified using semi-structured in- terviews and focus groups with 6th grade teachers. Educational modules for five most critical identified spots (Maps, Geographic coordinates, Time zones, Atmos- pheric circulation, Tectonic plates and its motion) were designed focusing on over- coming of causes of its criticality (missing curriculum continuity, high requirements on pupil’s imagination, complexity of the topic, insufficient motivation, transition from knowledge to competence). Teachers tested modules during their lessons and subsequently evaluated its success with overcoming the critical spots. This paper presents the „Time zones“ module and results of its evaluation as well as the meth- odological background of its design and the insight into the wider field of critical spot’s issues.