A comprehensive review on the machining process: unconventional as an alternative to conventional machining

Cutting/machining has been an integral part of human civilization since the beginning of the Stone Age. With time the cutting tools have evolved but the methods of cutting/machining remain the same. Thus, typical machining techniques lack several characteristics, such as material compatibility, difficulty in working with, inability to manufacture varied sizes and shapes, and so on. Thus, there have been introduced unconventional machining processes that can be used to cut various composite materials, make them easier to operate and machine complex shapes, etc. This chapter focuses on why unconventional machining processes can be an expedient alternative to conventional machining.</p

Carbon-dioxide corrosion in stainless steel (304L) pipes

This research comprehensively addresses challenges associated with carbon dioxide (CO2) corrosion in 304L stainless steel pipes, particularly under high temperatures and elevated CO2 partial pressures. Utilizing advanced simulation techniques with COMSOL Multiphysics, the corrosion behavior of 304L stainless steel is systematically investigated. Critical factors influencing corrosion rates, including operating temperature, reference temperature, initial electrolyte potential, and CO2 partial pressure, are identified. The study proposes practical mitigation strategies, such as employing more resistant materials like duplex stainless steel and applying protective coatings on inner pipe surfaces. The second study focuses on simulating and analyzing CO2 corrosion in 304L stainless steel pipes, aiming to address research gaps. The results facilitate the design and operation of systems utilizing 304L stainless steel in CO2 environments more effectively. Implementing measures to reduce PCO2 can diminish the corrosion rate, extending the system's lifespan

Systematic review of evidence for conservative management of pelvic organ prolapse in younger women

IntroductionTreatment of pelvic organ prolapse (POP) is poorly understood in younger women as the majority of prolapse research is conducted in the older population. There is an urgent need to evaluate conservative POP treatments for management in younger women due to high surgical complications and reoperation rates.MethodsSystematic review of the literature following PRISMA guidelines and registered in PROSPERO. Included studies were of conservative treatments in women younger than 51 years old.ResultsFrom 416 retrieved studies, nine were included in the analysis. Two of three studies found pelvic floor muscle training (PFMT) significantly benefited patient reported outcome measures (PROM) compared to educational material. One of three studies found significant improvement in PROM using biofeedback in addition to PFMT versus PFMT alone. Electrical stimulation with PFMT versus PFMT alone (one study) showed significant additional benefit of the combined treatment. Biofeedback and electrical stimulation in combination with PFMT versus PFMT alone (one study) was found to provide significant additional benefits. One compared pessary use to no intervention but stopped early due to slow recruitment.ConclusionPFMT improves patient reported outcomes in younger women with POP. Electrical stimulation and biofeedback are useful adjuncts to PFMT. The gap in research investigating the effect of pessaries in younger women warrants further study.<br/

A novel flow channel inspired by classical mathematical function: enhancing output performance and low-grade heat recovery efficiency of thermal regeneration ammonia-based flow battery

Thermal Regeneration Ammonia-based Flow Battery (TRAFB) faces significant challenges in enhancing its output performance and low-grade waste heat recovery efficiency due to limitations in mass transfer and an incomplete understanding of the mass transfer mechanism. To address these issues, this study innovatively introduces a novel sinusoidal wave flow channel (SWFC), which is inspired by the classic mathematical function. The impact of the SWFC on TRAFB performance is thoroughly discussed and compared in detail with the conventional straight flow channel (SFC). Most importantly, this work unveils for the first time the distribution mechanism of the three mass transfer modes in TRAFB, which are convection, diffusion, and electrophoretic mass transfer. The main findings reveal that the mass transfer performance of TRAFB is primarily governed by convection and diffusion, with electrophoretic mass transfer playing a minimal role, and there is a threshold of current density beyond which the dominant mass transfer mechanism transitions from convection to diffusion. The unique design of the SWFC, which induces the Venturi effect, significantly enhances the overall mass transfer performance of the TRAFB due to the distinct local acceleration, achieving a remarkable enhancement in flux of up to 118.48 times. By optimizing the amplitude and period, the battery's output performance can be further enhanced, with the maximum peak power achieved by the SWFC with an amplitude of 0.8 mm and a period of 0.5π, which is 95.63 % over the SFC. Notably, the SWFC also excels in improving the thermoelectric conversion efficiency, particularly at high current densities, achieving an enhancement of up to 9.81 times.</p

Overconsumption in the global fashion industry: desire, power and capitalism

The global fashion industry is dealing with a litany of issues of its own making: ecological disasters, human rights abuses, carbon emissions, hazardous chemicals, overproduction, product dumping and overconsumption to name a few. Overconsumption supports the range of issues faced by the fashion industry today. Overconsumption makes growth possible in an already saturated fashion market. Few discussions to date have aimed to unpack the complicated and nuanced relationship consumers have to fashion companies, the role of power in that relationship and the impact of desire on consumer’s ability to effect change in their consumption habits. This chapter examines consumer narratives through Foucault and Barthes to understand how power and desire are employed in the shared language of fashion. Reflecting on 100 impromptu street interviews with fashion consumers in busy New York City shopping areas in Spring 2019, the relationship between fashion consumers and fashion companies and the nature of power in that relationship are probed. In better understanding the power dynamics between consumers and companies, fashion overconsumption can be unpacked and examined with the hope of finding ways to reduce the negative effects of this complicated issue

Deep learning with dual-stage attention mechanism for interpretable prediction of proton exchange membrane fuel cell performance degradation

Accurate and reliable estimation of performance degradation in proton exchange membrane fuel cells (PEMFCs) can contribute to the maintenance and risk management of fuel cell systems. However, current research overly emphasizes model ensemble strategies and data preprocessing, neglecting the improvement of internal mechanisms within the models. Few models can adequately capture the long-term dependencies of relevant features. In this study, a dual-stage attention mechanism (DA) network structure called DA-LSTM was developed based on the Long Short-Term Memory (LSTM) neural network to predict the performance degradation of PEMFCs. In the first stage, an input attention mechanism is introduced, utilizing an encoder to adaptively extract important information from each time step of the input features. In the second stage, a temporal attention mechanism is employed to obtain relevant temporal attention factors across all time steps. The proposed approach is tested on various datasets and exhibits favorable predictive performance for PEMFC performance degradation. When compared to different models, the DA-LSTM consistently outperforms other models, demonstrating superior stability and predictive capability. Additionally, the visualization of attention weights explains the relationship between input features and the performance degradation of PEMFC. This enables real-time monitoring of fuel cell systems, which in turn helps prolong the lifespan of PEMFC.</p

The optical nature of myopic changes in retinal vessel calibre

PURPOSE: Dimensional measures of retinal features are subject to the optical influence of ocular magnification. We examined the impact of ocular magnification on the association between axial length (AL) and measurements of retinal vessel caliber in fundus photographs.DESIGN: Cross-sectional study.PARTICIPANTS: Eighty-two normal right eyes from healthy participants aged 16 to 31 years.METHODS: Central retinal arteriolar and venular equivalents (CRAE and CRVE) were derived from color fundus photographs using semiautomated software. Ordinary least squares linear regression was used to assess the influence of AL (independent variable) on CRAE and CRVE, controlling for age, sex, and ethnicity, both before and after magnification correction using different formulae. These formulae estimate magnification based on different ocular parameters: AL only (Bennnett's formula), refractive error only (Bengtsson's formula), and refractive error combined with keratometry (Littmann's formula). Previous research has primarily relied on Bengtsson's formula, which is less accurate than Bennett's formula. We also examined the impact of treating the nontelecentric fundus camera used in this study as telecentric when applying these magnification correction formulae.MAIN OUTCOME MEASURES: Central retinal arteriolar and venular equivalents (in pixels).RESULTS: Before magnification correction, increasing AL was associated with decreasing CRAE (β: -0.49, 95% confidence intervals: -0.89 to -0.09, P = 0.02) and CRVE (β: -0.91, 95% confidence intervals: -1.62 to -0.20, P = 0.01). After magnification correction, this observation was no longer evident, regardless of the correction formula applied. When inappropriately assuming the fundus camera to be telecentric, we observed a bias toward increasing magnification-corrected CRAE and CRVE with increasing AL (β coefficients were positive or became more positive), reaching statistical significance ( P &lt; 0.05) for CRAE corrected using Bennett's or Littmann's formula, and for CRVE corrected using Bennett's formula. CONCLUSIONS: Failing to correct for ocular magnification results in apparent narrowing of vessels in longer eyes, while inappropriate assumptions about telecentricity during magnification correction introduce an optical artifact that causes apparent widening of vessels. These findings suggest that myopic changes in retinal vessel caliber are optical (not biological) in nature. Proper correction of this effect to accurately derive dimensional measures is a crucial-yet often overlooked-methodological consideration in "oculomics" research investigating retinal biomarkers of systemic conditions.FINANCIAL DISCLOSURES: Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.</p

Social determinants and consequences of pain: towards multilevel, intersectional, and life course perspectives

Despite wide endorsement of a biopsychosocial framework for pain, social aspects of pain remain rarely addressed in the context of pain prevention and management. In this review, we aim to: 1) examine the broad scope of social determinants and consequences of pain and their interactions across multiple levels of organization, and 2) provide a framework synthesizing existing concepts and potential areas for future work on social aspects of pain, drawing upon socioecological, intersectional, and life course approaches. Integrating interdisciplinary theory and evidence, we outline pathways through which multilevel social factors and pain may affect each other over time. We also provide a brief summary of intrapersonal aspects of pain which are thought to operate at the interface between individuals and the social context. Progressing from micro- to macro-level factors, we illustrate how social determinants of pain can directly or indirectly contribute to pain experiences, expression, risk, prognosis, and impact across populations. We consider: a) at the interpersonal level, the roles of social comparison, social relatedness, social support, social exclusion, empathy and interpersonal conflict; b) at the group or community level, the roles of intimacy groups, task groups, social categories, and loose associations; and c) at the societal level, the roles of political, economic, and cultural systems, as well as their policies and practices. We present examples of multilevel consequences of pain across these levels and discuss opportunities to reduce the burden and inequities of pain by expanding multilevel social approaches in pain research and practice

Longitudinal analysis of functional capacity in nursing home residents during the COVID-19 pandemic

Background and Purpose: The COVID-19 pandemic has raised concerns about nursing home (NH) residents’ well-being, with recent studies indicating a significant increase in functional decline rate during this critical period. However, a comprehensive exploration of functional capacity trajectories in NH residents during the pandemic remains unexplored. This study aims to address this research gap by conducting an in-depth analysis of the impact of the COVID-19 pandemic on NH residents’ functional capacity.Methods: A 24-month multicenter prospective study involving 123 NH residents from Spain, with data collected at 6-month intervals over 5 waves, starting just before the pandemic’s onset. Functional capacity was assessed using the Modified Barthel Index, and data were analyzed employing the actuarial method, log-rank test, and Cox’s regression.Results and Discussion: The likelihood of maintaining functional capacity was unfavorable, with only a 19.3% chance of preservation for a 1-point decline (FD-1) in Barthel scores and a 50.5% probability for a 10-point decline (FD-10). Personal hygiene, eating, and toilet use were identified as the most affected activities of daily living. Urinary continence decline emerged as a risk factor for FD-1, while fecal continence decline was associated with FD-10. The probability of maintaining functional capacity in the initial 6 months of a pandemic was comparable to a 2-year non-pandemic follow-up. Pandemic-induced isolation strategies significantly impacted toileting and personal hygiene. Urinary decline was associated with minor functional decline (FD-1), while fecal decline correlated with major functional decline (FD-10). Notably, the number of days spent in room confinement did not significantly contribute to the observed decline.Conclusions: A substantial increase in the risk of FD among NH residents during the COVID-19 pandemic compared to the pre-pandemic period was found. It is crucial to implement urgent, targeted interventions that prioritize promoting physical activity and the implementation of mobility and toileting programs. These measures are pivotal for mitigating functional decline and enhancing the overall health and well-being of NH residents in a pandemic context