A Perspective on Tribology and Design

2021 ◽  
Vol 143 (5) ◽  
Author(s):  
Nam Pyo Suh

Abstract The quality of design determines the performance of all tribological systems. Tribological failures of the system may be avoided through rational and creative design. In that sense, there is a symbiotic relationship between tribology and design. Many tribology problems encountered are often the result of poor system design. By properly designing the tribological system, potential failures caused by friction and wear can be avoided or minimized. Continuous testing of poorly designed tribological systems, which occur in some cases, can be costly without noticeable improvements in the system performance. Since well-designed products yield immense benefits, the creation of tribological systems based on rational design should be pursued. The biggest source of tribological problems is the coupling of the functional requirements (FRs) that are introduced during the early stage of design. We should attempt to eliminate coupled tribological systems to improve the performance of tribological systems. Some examples are given to illustrate the importance of rational designs in implementing tribological systems, including the design of additive manufacturing systems.

Author(s):  
Nam Pyo Suh

Abstract Tribology — the science and engineering of friction, wear, and lubrication — enables the design of engineered systems with moving parts to achieve its intended functions. Many systems are so well designed already that they work as expected without requiring much attention, most of the time. However, when a system fails because of tribological problems, we may have a major disaster that may bring down the entire system, such as vehicles, engines, machinery, and even factories. Fortunately, the field of tribology has so far advanced, though often empirically, that many systems usually perform well. For instance, commercial airplanes are airborne for days without maintenance; windmills in the middle of the sea produce electricity for years; the tires of automobiles now last much longer than they used to, and machine tools make products for many months with minimal maintenance. Yet, there are still many unsolved tribology problems that require solutions. The ultimate goal of a tribological system is a life-time operation without any failure. The quality of design determines the performance of tribological systems. Tribological failures of the system may be avoided through rational and creative design. In that sense, there is a symbiotic relationship between tribology and design. Many tribology problems encountered are often the result of poor system design. By properly designing the tribological system, potential failures caused by friction and wear can be avoided or minimized. Continuous testing of poorly designed tribological systems, which occurs in some cases, can be costly and with no noticeable improvements in the system performance. Since well-designed products yield immense benefits, the creation of tribological systems based on rational design should be pursued. The biggest source of tribological problems is the coupling of the functional requirements (FRs) that are introduced in the early stages of design. Attempts should be made to eliminate coupled tribological systems to improve their performance.


2021 ◽  
pp. 100157
Author(s):  
Somaresh Kumar Mondal ◽  
Abdul Gaffar Khan ◽  
Md. Mamun Ali ◽  
Mir Kaosar Ahamed ◽  
Kawsar Ahmed

Sensors ◽  
2021 ◽  
Vol 21 (3) ◽  
pp. 863
Author(s):  
Vidas Raudonis ◽  
Agne Paulauskaite-Taraseviciene ◽  
Kristina Sutiene

Background: Cell detection and counting is of essential importance in evaluating the quality of early-stage embryo. Full automation of this process remains a challenging task due to different cell size, shape, the presence of incomplete cell boundaries, partially or fully overlapping cells. Moreover, the algorithm to be developed should process a large number of image data of different quality in a reasonable amount of time. Methods: Multi-focus image fusion approach based on deep learning U-Net architecture is proposed in the paper, which allows reducing the amount of data up to 7 times without losing spectral information required for embryo enhancement in the microscopic image. Results: The experiment includes the visual and quantitative analysis by estimating the image similarity metrics and processing times, which is compared to the results achieved by two wellknown techniques—Inverse Laplacian Pyramid Transform and Enhanced Correlation Coefficient Maximization. Conclusion: Comparatively, the image fusion time is substantially improved for different image resolutions, whilst ensuring the high quality of the fused image.


2021 ◽  
Vol 13 (8) ◽  
pp. 195
Author(s):  
Akash Gupta ◽  
Adnan Al-Anbuky

Hip fracture incidence is life-threatening and has an impact on the person’s physical functionality and their ability to live independently. Proper rehabilitation with a set program can play a significant role in recovering the person’s physical mobility, boosting their quality of life, reducing adverse clinical outcomes, and shortening hospital stays. The Internet of Things (IoT), with advancements in digital health, could be leveraged to enhance the backup intelligence used in the rehabilitation process and provide transparent coordination and information about movement during activities among relevant parties. This paper presents a post-operative hip fracture rehabilitation model that clarifies the involved rehabilitation process, its associated events, and the main physical movements of interest across all stages of care. To support this model, the paper proposes an IoT-enabled movement monitoring system architecture. The architecture reflects the key operational functionalities required to monitor patients in real time and throughout the rehabilitation process. The approach was tested incrementally on ten healthy subjects, particularly for factors relevant to the recognition and tracking of movements of interest. The analysis reflects the significance of personalization and the significance of a one-minute history of data in monitoring the real-time behavior. This paper also looks at the impact of edge computing at the gateway and a wearable sensor edge on system performance. The approach provides a solution for an architecture that balances system performance with remote monitoring functional requirements.


2020 ◽  
Vol 18 (6) ◽  
pp. 648-657
Author(s):  
Karen E. Steinhauser ◽  
Karen M. Stechuchak ◽  
Katherine Ramos ◽  
Joseph Winger ◽  
James A. Tulsky ◽  
...  

AbstractObjectiveCompare the efficacy of two interventions addressing emotional and existential well-being in early life-limiting illness.MethodPrimary trial analysis (n = 135) included patients with advanced cancer, congestive heart failure, or end-stage renal disease; Arm 1 received the Outlook intervention, addressing issues of life completion and preparation, and Arm 2 received relaxation meditation (RM). Primary outcomes at five weeks (primary endpoint) and seven weeks (secondary): completion and preparation (QUAL-E); secondary outcomes: anxiety (POMS) quality of life (FACT-G) and spiritual well-being (FACIT-Sp) subscales of faith, meaning, and peace.ResultsAverage age was 62; 56% were post-high school-educated, 54% were married, 52% white, 44% female, and 70% had a cancer diagnosis. At baseline, participants demonstrated low levels of anxiety (<5 on POMS subscale) and depression (<10 on CESD) relative to population norms. Results of the primary analysis revealed no significant differences in mean Preparation by treatment arm at five weeks (14.4 Outlook vs. 14.8 RM; between-group difference −0.4 [95% CI, −1.6, 0.8], p = 0.49) or seven weeks (15.2 vs.15.4; between-group difference −0.2 [95% CI, −1.5, 1.0], p = 0.73). There were also no significant differences in mean Life Completion by treatment arm between five weeks (26.6 Outlook vs. 26.3 RM; between-group difference 0.2 [95% CI, −1.2, 1.7], p = 0.76) or seven weeks (26.5 vs. 27.5; between-group difference −1.0 [95% CI, −2.7, 0.7], p = 0.23). Compared to RM, Outlook participants did not have significant differences over time in the secondary outcomes of overall quality of life, anxiety, depression, FACT-G subscales, and FACIT-Sp subscales.DiscussionIn early-stage life-limiting illness, Outlook did not demonstrate a significant difference in primary or secondary outcomes relative to RM. Results underscore the importance of pre-screening for distress. Qualitatively, Outlook participants were able to express suppressed emotions, place illness context, reflect on adaptations, and strengthen identity. Screening for distress and identifying specified measures of distress, beyond anxiety and depression, is essential in our ability to adequately assess the multi-dimensional mechanisms that decrease existential suffering.


Antioxidants ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 860
Author(s):  
Wu-Sheng Sun ◽  
Hoon Jang ◽  
Mi-Ryung Park ◽  
Keon Bong Oh ◽  
Haesun Lee ◽  
...  

Oxidative stress has been suggested to negatively affect oocyte and embryo quality and developmental competence, resulting in failure to reach full term. In this study, we investigated the effect of N-acetyl-L-cysteine (NAC), a cell-permeating antioxidant, on developmental competence and the quality of oocytes and embryos upon supplementation (0.1–10 mM) in maturation and culture medium in vitro using slaughterhouse-derived oocytes and embryos. The results show that treating oocytes with 1.0 mM NAC for 8 h during in vitro maturation attenuated the intracellular reactive oxygen species (ROS) (p < 0.05) and upregulated intracellular glutathione levels (p < 0.01) in oocytes. Interestingly, we found that NAC affects early embryonic development, not only in a dose-dependent, but also in a stage-specific, manner. Significantly (p < 0.05) decreased cleavage rates (90.25% vs. 81.46%) were observed during the early stage (days 0–2), while significantly (p < 0.05) increased developmental rates (38.20% vs. 44.46%) were observed during the later stage (from day 3) of embryonic development. In particular, NAC supplementation decreased the proportion of apoptotic blastomeres significantly (p < 0.05), resulting in enhanced hatching capability and developmental rates during the in vitro culture of embryos. Taken together, our results suggest that NAC supplementation has beneficial effects on bovine oocytes and embryos through the prevention of apoptosis and the elimination of oxygen free radicals during maturation and culture in vitro.


Author(s):  
Vladica M. Velickovic ◽  
Jean P. Lembelembe ◽  
Francisco Cegri ◽  
Ivana Binic ◽  
Amr B. Abdelaziz ◽  
...  

The aim of the research is to assess the benefit–harm of superabsorbent polymers wound dressings based on polyacrylate polymers (SAPs) compared with standard of care (SoC) dressing mix for patients with moderate-to-highly exuding hard-to-heal leg ulcers. The SoC dressings mix was composed of other superabsorbents in 29% of cases, antimicrobials 26%, foams 20%, alginates 5%, and other dressings 19% weighted according to their frequency. We have used the decision-analytic modeling method, Markov process, as an adequate analytical solution for medical prognosis. We have combined the systematic literature search to identify the most relevant inputs for the analysis, with available patient-level clinical data concerning benefits of superabsorbent to generate a robust prediction of patient-relevant outcomes, including healing rates and health-related quality of life. Besides, we have qualitatively described adverse events associated with those treatments. Our research indicates that SAPs when compared with SoC dressing mix in a patient with moderate-to-highly excluding leg ulcers are leading to an improved healing rate with an absolute risk difference of 2.20% in 6 months and a relative risk of 1.07 in favor of SAP dressings. The attributable fraction among those exposed to SAP dressings of 6.6%, meaning that 6.6% of the healed ulcers could be attributed to having had the SAP dressing treatment instead of the SoC dressing treatment. Besides, SAP dressings lead to improved quality of life measured as incremental quality-adjusted life weeks (QALWs) of 0.13 QALWs.


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