Search results for: perception of aging

Authors: S. H. Bae, D. W. Cho, W. B. Jeong, J. R. Cho

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Fatigue fracture of an aluminum welded structure is a phenomenon frequently occurring from pores in a weld. In order to grasp the state of the welded structure in operation in real time, the acceleration signal of the structure is measured. At this time, the vibration characteristic of the signal according to the fatigue load is an important parameter of the state diagnosis. This paper was an experimental study on the variation of vibration characteristics of welded beams with vibration aging (especially bending vibration). First simple beams were produced according to welding conditions. Each beam was vibrated and measured beam's PSD (power spectral density) according to the degree of aging. Also, modal testing was conducted to compare the transfer functions of welded beams. Testing result shows that the natural frequencies of the beam changed with the vibration aging due to the change of stiffness in welding part and its stiffness was estimated by the finite element method.

Keywords: modal testing, natural frequency, vibration aging, welded structure

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Authors: Kushal Gowda Jayaram, Joseph Huret, Jonathan Quibel, Walter-John Chitty, Gilbert Henaff

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Thermal aging is one of the concerns for the long-term operation of nuclear power plants. Indeed, components in the primary circuit undergo thermal aging while exposed to the chemically active environment of Pressurized Water Reactors (PWRs) over time. Among the materials used in the reactor components, Alloy 690 can be found in some critical components for nuclear safety. Despite its importance, research on the effect of thermal aging on the microstructural changes and low cycle fatigue (LCF) behavior of Alloy 690 remains limited. This study aims to assess the impact of thermal aging on the fatigue life of Alloy 690. The as-received sample underwent aging at 420°C for 4000 hours, representing the equivalent aging of 60 years in reactor working conditions. First, the characterization of the area and density of intergranular and intragranular precipitates was performed to understand the microstructural changes in the aged specimen. Then, low cycle fatigue tests were conducted on the as received and aged samples at varying strain amplitudes. To investigate the influence of thermal aging on the fatigue behavior of Alloy 690, fracture surfaces were analyzed to estimate fatigue crack growth rates based on striation spacing measurements. Additionally, the axially cut fractured samples have undergone analysis using Electron Backscatter Diffraction (EBSD) to understand the effect of aging on strain localization near the crack path. Results indicate that while the characterization of the area and density of intergranular precipitates in the aged specimen (for 2000 hours, approximately 30 years) showed no significant changes, there was a slight increase in the area and density of intragranular precipitates under the same conditions.

Keywords: alloy 690, thermal aging, low cycle fatigue, precipitates

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Authors: K. A. Tharanga, K. H. H. Damayanthi

Abstract:

Perception is an epistemological concept discussed in Philosophy. Perception, in other word, vision, is one of the ways that human beings get empirical knowledge after five senses. However, we face innumerable problems when achieving knowledge from perception, and therefore the knowledge gained through perception is uncertain. what we see in the external world is not real. These are the major issues that we face when receiving knowledge through perception. Sometimes there is no physical existence of what we really see. In such cases, the perception is relative. The following frames will be taken into consideration when perception is analyzed illusions and delusions, the figure of a physical object, appearance and the reality of a physical object, time factor, and colour of a physical object.seeing and knowing become vary according to the above conceptual frames. We cannot come to a proper conclusion of what we see in the empirical world. Because the things that we see are not really there. Hence the scientific knowledge which is gained from observation is doubtful. All the factors discussed in science remain in the physical world. There is a leap from ones existence to the existence of a world outside his/her mind. Indeed, one can suppose that what he/she takes to be real is just anmassive deception. However, depending on the above facts, if someone begins to doubt about the whole world, it is unavoidable to become his/her view a scepticism or nihilism. This is a certain reality.

Keywords: empirical, perception, sceptisism, nihilism

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Authors: Bright Kwakye-Awuah, Elizabeth Von-Kiti, Isaac Nkrumah, Baah Sefa-Ntiri, Craig D. Williams

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Bauxite and kaolin from Ghana Bauxite Company mine site were used to synthesize zeolites. Bauxite served as the alumina source and kaolin the silica source. Synthesis variations include variation of aging time at constant crystallization time and variation of crystallization times at constant aging time. Characterization techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive x-ray analysis (EDX) and Fourier transform infrared spectroscopy (FTIR) were employed in the characterization of the raw samples as well as the synthesized samples. The results obtained showed that the transformations that occurred and the phase of the resulting products were coordinated by the aging time, crystallization time, alkaline concentration and Si/Al ratio of the system. Zeolites A, X, Y, analcime, Sodalite, and ZK-14 were some of the phases achieved. Zeolite LTA was achieved with short crystallization times of 3, 5, 18 and 24 hours and a maximum aging of 24 hours. Zeolite LSX was synthesized with 24 hr aging followed with 24 hr hydrothermal treatment whilst zeolite Y crystallized after 48 hr of aging and 24 hr crystallization. Prolonged crystallization time produced a mixed phased product. Prolonged aging times, on the other hand, did not yield any zeolite as the sample was amorphous. Increasing the alkaline content of the reaction mixture above 5M introduced sodalite phase in the final product. The properties of the final products were comparable to zeolites synthesized from pure chemical reagents.

Keywords: bauxite, kaolin, aging, crystallization, zeolites

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Authors: Ziya Esen, Özgür Duygulu, Nazlı S. Büyükatak

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This study investigates the effects of aging heat treatment on corrosion resistance and mechanical properties of WE43 Magnesium alloy. The heat treatment of alloys was conducted by solutionizing at 525oC for 16 h, followed by aging at 190, 210 and 230oC for up to 48 h. The type and the size of precipitates formed upon aging have influenced both the mechanical properties and corrosion behavior of the alloy. Solutionized alloy displayed the worst corrosion resistance in simulated body fluid, while peak hardness and the best corrosion resistance were observed in the alloy aged at 210oC for 24 h as a result of β’ precipitate formation. Longer aging duration at 210oC decreased the corrosion rate due to the coarsening of the precipitates and formation of precipitate-free zones. The increased corrosion resistance of the peak aged samples was attributed to the slowing down effect of the Mg(OH)₂/MgO corrosion layer by the pinning effect of β’-precipitates.

Keywords: WE43 magnesium alloy, simulated body fluid, corrosion, mechanical properties

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Authors: K. A.Tharanga, K. H. H. Damayanthi

Abstract:

Perception is an epistemological concept discussed in Philosophy. Perception, in other word, vision, is one of the ways that human beings get empirical knowledge after five senses. However, we face innumerable problems when achieving knowledge from perception, and therefore the knowledge gained through perception is uncertain. what we see in the external world is not real. These are the major issues that we face when receiving knowledge through perception. Sometimes there is no physical existence of what we really see. In such cases, the perception is relative. The following frames will be taken into consideration when perception is analyzed illusions and delusions, the figure of a physical object, appearance and the reality of a physical object, time factor, and colour of a physical object. seeing and knowing become vary according to the above conceptual frames. We cannot come to a proper conclusion of what we see in the empirical world. Because the things that we see are not really there. Hence the scientific knowledge which is gained from observation is doubtful. All the factors discussed in science remain in the physical world. There is a leap from ones existence to the existence of a world outside his/her mind. Indeed, one can suppose that what he/she takes to be real is just a massive deception. However, depending on the above facts, if someone begins to doubt about the whole world, it is unavoidable to become his/her view a scepticism or nihilism. This is a certain reality.

Keywords: empirical, perception, sceptisism, nihilism

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Authors: Mustafa Akpolat, Baha Vural Kök

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Using a waste material such as crumb rubber (CR) obtained by waste tires has become an important issue in respect to sustainability. However, the CR modified mixture also requires high manufacture temperature as a polymer modified mixture. For this reason in this study, it is intended to produce a CR modified mixture with warm mix asphalt additives in the same mixture. Asphalt mixtures produced by pure, 10%CR, 10%CR+3% Sasobit and 10%CR+0.7% Evotherm were subjected to aging procedure in the laboratory and the field. The indirect tensile repeated tests were applied to aged and original specimens. It was concluded that the fatigue life of the mixtures increased significantly with the increase of aging time. CR+Sasobit modified mixture aged at the both field and laboratory gave the highest load cycle among the mixtures.

Keywords: crumb rubber, warm mix asphalt, aging, fatigue

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Authors: N. Kaneva, A. Bojinova, K. Papazova

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Thin ZnO films are deposited on glass substrates via sol–gel method and dip-coating. The films are prepared from zinc acetate dehydrate as a starting reagent. After that the as-prepared ZnO sol is aged for different periods (0, 1, 3, 5, 10, 15, and 30 days). Nanocrystalline thin films are deposited from various sols. The effect ZnO sols aging time on the structural and photocatalytic properties of the films is studied. The films surface is studied by Scanning Electron Microscopy. The effect of the aging time of the starting solution is studied inrespect to photocatalytic degradation of Reactive Black 5 (RB5) by UV-vis spectroscopy. The experiments are conducted upon UV-light illumination and in complete darkness. The variation of the absorption spectra shows the degradation of RB5 dissolved in water, as a result of the reaction acurring on the surface of the films, and promoted by UV irradiation. The initial concentrations of dye (5, 10 and 20 ppm) and the effect of the aging time are varied during the experiments. The results show, that the increasing aging time of starting solution with respect to ZnO generally promotes photocatalytic activity. The thin films obtained from ZnO sol, which is aged 30 days have best photocatalytic degradation of the dye (97,22%) in comparison with the freshly prepared ones (65,92%). The samples and photocatalytic experimental results are reproducible. Nevertheless, all films exhibit a substantial activity in both UV light and darkness, which is promising for the development of new ZnO photocatalysts by sol-gel method.

Keywords: ZnO thin films, sol-gel, photocatalysis, aging time

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Authors: Li-Te Lin, Chia-Jung Li, Kuan-Hao Tsui

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Cuproptosis, a newly identified cell death mechanism, has attracted attention for its association with various diseases. However, the genetic interplay between cuproptosis and ovarian aging remains largely unexplored. This study aims to address this gap by analyzing datasets related to ovarian aging and cuproptosis. Spatial transcriptome analyses were conducted in the ovaries of both young and aged female mice to elucidate the role of FDX1. Comprehensive bioinformatics analyses, facilitated by R software, identified FDX1 as a potential cuproptosis-related gene with implications for ovarian aging. Clinical infertility biopsies were examined to validate these findings, showing consistent results in elderly infertile patients. Furthermore, pharmacogenomic analyses of ovarian cell lines explored the intricate association between FDX1 expression levels and sensitivity to specific small molecule drugs. Spatial transcriptome analyses revealed a significant reduction in FDX1 expression in aging ovaries, supported by consistent findings in biopsies from elderly infertile patients. Pharmacogenomic investigations indicated that modulating FDX1 could influence drug responses in ovarian-related therapies. This study pioneers the identification of FDX1 as a cuproptosis-related gene linked to ovarian aging. These findings not only contribute to understanding the mechanisms of ovarian aging but also position FDX1 as a potential diagnostic biomarker and therapeutic target. Further research may establish FDX1's pivotal role in advancing precision medicine and therapies for ovarian-related conditions.

Keywords: cuproptosis, FDX1, ovarian aging, biomarker

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Authors: Chia-Jung Li, Li-Te Lin, Kuan-Hao Tsui

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The study identifies SPP1 as a potential gene associated with ovarian aging, revealing a significant decline in its expression in aged ovaries. SPP1, also known as osteopontin (OPN), is a multifunctional glycoprotein involved with regulatory proteins and pro-inflammatory immune chemokines. However, its genetic links to ovarian aging have not been extensively explored. Spatial transcriptomic analyses were conducted on ovaries from young and aged female mice, along with a sample from a 73-year-old individual. Additionally, single-cell RNA sequencing analysis was performed to identify associations between SPP1 and key genes. The study focused on crucial genes, including ITGAV, ITGB1, CD44, MMP3, and FN1, with a particular emphasis on the correlation between SPP1 and ITGB1. The findings indicate a significant decline in SPP1 expression in aged ovaries, which was consistent in the 73-year-old sample. Single-cell RNA sequencing unveiled associations between SPP1 and key genes, emphasizing a strong co-expression correlation between SPP1 and ITGB1. While the study provides valuable insights, further research is necessary to understand the broader implications and potential applications of SPP1 in ovarian aging. Translating these findings to clinical settings requires careful consideration. The identification of SPP1 as a gene implicated in ovarian aging opens new avenues for advancing precision medicine and refining treatment strategies for conditions related to ovarian aging.

Keywords: SPP1, ovarian aging, spatial transcriptomic, single-cell RNA sequencing

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Authors: Ricardo Mendoza, Jason Briceño, Juan F. Santa, Gabriel Peluffo, Mauricio Márquez, Beatriz Cardozo, Carlos Gutiérrez

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Coir natural fiber reinforced polyester composites were exposed to an accelerated environment aging in order to study the influence on the mechanical properties. Coir fibers were obtained in local plantations of the Caribbean coast of Colombia. A physical and mechanical characterization was necessary to found the best behavior between three types of coconut. Composites were fabricated by hand lay-up technique and samples were cut by water jet technique. An accelerated aging test simulates environmental climate conditions in a hygrothermal and ultraviolet chamber. Samples were exposed to the UV/moisture rich environment for 500 and 1000 hours. The tests were performed in accordance with ASTM G154. An additional water absorption test was carried out by immersing specimens in a water bath. Mechanical behaviors of the composites were tested by tensile, flexural and impact test according to ASTM standards, after aging and compared with unaged composite specimens. It was found that accelerated environment aging affects mechanical properties in comparison with unaged ones. Tensile and flexural strength were lower after aging, meantime elongation at break and flexural deflection increased. Impact strength was found that reduced after aging. Other result revealed that the percentage of moisture uptake increased with aging. This results showed that composite materials reinforced with natural fibers required an improvement adding a protective barrier to reduce water absorption and increase UV resistance.

Keywords: coir fiber, polyester composites, environmental aging, mechanical properties

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Authors: Fahimeh Khatami, Maryam Ziyaee, Elham Sanagar Darbani

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Variety of different factors could influence on the measure urban perception. Both physical and non-physical factors, at least, make the quality of perception through the urban spaces. The value of lighting is one of the important factors which could make the better quality of environmental perception for the user. The perception of urban space in most of the Iranian cities is offer by different factors during the night time which caused to the death of nightlife and social activities. Therefore, this research is an attempt to study on the different of user perception during day and night in the Koohsangi Street. As the case study area in Iran in order to bring out the main influential factors during perception process. To deal with this good we used chi-square test on a sample size made up of on hundred participants. The result shows that for improving the night quality of urban spaces the legibility, navigation, and role stimulation were in important perception factors. Therefore, by focusing on these factors it would be possible to find out more functional solution for improving the activity of night perception.

Keywords: perception, urban space, legibility, imageability, nightscape

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Authors: Triana Fitriastuti, Pipiet Larasatie, Alex Vanderstraten

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Many scholars have demonstrated the negative impacts of the perception of organizational politics on organizational outcomes. The model proposed in this study analyzes the impact of the perception of organizational politics on job satisfaction. In the same way, ingratiation as a moderator variable is tested. We applied regression analysis to test the hypothesis. The findings of the current research, which was conducted with 240 employees in the public sector in Indonesia, show that the perception of organizational politics has a negative effect on job satisfaction. In contrast, ingratiation plays a role that fully moderates the relationship between organizational politics and organizational outcomes and changes the correlation between the perception of organizational politics on job satisfaction. Employees who use ingratiation as a coping mechanism tend to do so when they perceive a high degree of organizational politics.

Keywords: ingratiation, impression management, job satisfaction, perception of organizational politics

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Authors: Xuemei Yang, Xin Sun, Cheng Fu, Qiong Lan, Chao Han

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Residual stresses, which can be produced during the manufacturing process of plastic bonded explosive (PBX), play an important role in weapon system security and reliability. Residual stresses can and do change in service. This paper mainly studies the influence of vibratory stress relief (VSR) and thermal aging on residual stress of explosives. Firstly, the residual stress relaxation of PBX via different physical condition of VSR, such as vibration time, amplitude and dynamic strain, were studied by drill-hole technique. The result indicated that the vibratory amplitude, time and dynamic strain had a significant influence on the residual stress relief of PBX. The rate of residual stress relief of PBX increases first and then decreases with the increase of dynamic strain, amplitude and time, because the activation energy is too small to make the PBX yield plastic deformation at first. Then the dynamic strain, time and amplitude exceed a certain threshold, the residual stress changes show the same rule and decrease sharply, this sharply drop of residual stress relief rate may have been caused by over vibration. Meanwhile, the comparison between VSR and thermal aging was also studied. The conclusion is that the reduction ratio of residual stress after VSR process with applicable vibratory parameters could be equivalent to 73% of thermal aging with 7 days. In addition, the density attenuation rate, mechanical property, and dimensional stability with 3 months after VSR process was almost the same compared with thermal aging. However, compared with traditional thermal aging, VSR only takes a very short time, which greatly improves the efficiency of aging treatment for explosive materials. Therefore, the VSR could be a potential alternative technique in the industry of residual stress relaxation of PBX explosives.

Keywords: explosives, residual stresses, thermal aging, vibratory stress relief, VSR

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Authors: Nasir A. Al-Geelani, Zulkurnain Abdul-Malek, M. Afendi M. Piah

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This research paper investigation is carried out in the laboratory on single units of transmission line glass insulator characterized by different thermal images, which aimed to find out the age of the insulators. The tests were carried out on virgin and aged insulators using the thermography scan. Various samples having different periods of aging 20, 15, and 5 years from a 132 kV transmission line which have exhibited a different degree of corrosion. The second group of insulator samples was relatively mild aged insulators, while the third group was lightly aged; finally, the fourth group was the brand new insulators. The results revealed a strong correlation between the aging and the thermal images captured by the infrared camera. This technique can be used to monitor the aging of high voltage insulators as a precaution to avoid disaster.

Keywords: glass insulator, infrared camera, corona diacharge, transmission lines, thermograpy, surface discharge

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Authors: Zoe Yang, Dena Shenk

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The goal of this research was to highlight stories from voices that are typically disregarded. Five older Asian Americans, who immigrated from Cambodia, Taiwan, and China, were interviewed in person, over Zoom, or through a phone call. Subjects were asked about their opinions towards aging and housing choices. Various Asian American stories reveal factors that contribute to the acceptance or rejection of aging. Through these interviews and research on cultural differences towards aging, findings indicate that personality, age, background, and health status affect one's relationship with housing choices and filial piety.

Keywords: assisted living, filial piety, housing choices, independent living

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Authors: Wan-I Chen, Tsung-I Pai

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Future the society aging of population will create the social problem has not had the good mechanism solution in the Asian country, especially in Taiwan. In the future ten year the people in Taiwan must facing the condition which is localization aging social problem. In this situation, how to use the spatial in eco way to development space use to solve the old age spatial demand is the way which might develop in the future Taiwan society. Over the next 10 years, taking care of the aging people will become part of the social problem of aging phenomenon. The research concentrate in the feasibility of spatial substitution, secondary use of spatial might solve out of spatial problem for aging people. In order to prove the space usable, the research required to review the project with the support system and infill system for space experiment, by using network grid way. That defined community level of space elements location relationship, make new definitions of space and return to cooperation. Research to innovation in the the appraisal space causes the possibility, by spatial replacement way solution on spatial insufficient suitable condition. To evaluation community spatial by using the support system and infill system in order to see possibilities of use in replacement inner space and modular architecture into housing. The study is discovering the solution on the Eco way to develop space use to figure out the old age spatial demand.

Keywords: sustainable use, space conversion, integration, replacement


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Authors: Amin Abbasi, Fariborz Shekari, Seyed Bahman Mousavi

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Seed aging during storage is a complex biochemical and physiological processes that can lead to reduce seed germination. This phenomenon associated with increasing of total antioxidant activity during aging. To study the effects of hormones on seed aging, aged wheat seeds (control, 90 and 80% viabilities) were treated with GA3, Salicylic Acid, and paclobutrazol and antioxidant system were investigated as molecular biomarkers for seed vigor. The results showed that, seed priming treatment significantly affected germination percentage, normality seedling percentage, H2O2, MDA, CAT, APX, and GPX activates. Maximum germination percentage achieve in GA3 priming in control treatment. Germination percentage and normal seedling percentage increased in other GA3 priming treatment compared with other hormones. Also aging increased MDA, H2O2 content. MDA is considered sensitive marker commonly used for assessing membrane lipid peroxidation and H2O2result in toxicity to cellular membrane system and damages to plant cells. Amount of H2O2 and MDA declined in GA3 treatment. CAT, GPX and APX activities were reduced by increasing the aging time and at different levels of priming. The highest APX activity was observed in Salicylic Acid control treatment and the highest GPX and CAT activity was obtained in GA3 control treatment. The lowest MDA and H2O2 showed in GA3 control treatment, too. Hormone priming increased Antioxidant enzyme activity and decreased amount of reactive oxygen space and malondialdehyde (MDA) under aging treatment. Also, GA3 priming treatments have a significant effect on germination percentage and number of normal seedling. Generally aging seed, increase ROS and lipid peroxidation. Antioxidant enzymes activity of aged seeds increased after hormone priming.

Keywords: hormones priming, wheat, aging seed, antioxidant, lipid peroxidation

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Authors: El Miloudi Djelloul

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Based on analysis on applications by perception control technology in computer network security status and security protection measures, from the angles of network physical environment and network software system environmental security, this paper provides network security system perception control solution using Internet of Things (IOT), telecom and other perception technologies. Security Perception Control System is in the computer network environment, utilizing Radio Frequency Identification (RFID) of IOT and telecom integration technology to carry out integration design for systems. In the network physical security environment, RFID temperature, humidity, gas and perception technologies are used to do surveillance on environmental data, dynamic perception technology is used for network system security environment, user-defined security parameters, security log are used for quick data analysis, extends control on I/O interface, by development of API and AT command, Computer Network Security Perception Control based on Internet and GSM/GPRS is achieved, which enables users to carry out interactive perception and control for network security environment by WEB, E-MAIL as well as PDA, mobile phone short message and Internet. In the system testing, through middle ware server, security information data perception in real time with deviation of 3-5% was achieved; it proves the feasibility of Computer Network Security Perception Control System.

Keywords: computer network, perception control system security strategy, Radio Frequency Identification (RFID)

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Authors: Faizan Asghar, Mohammad Jamal Khattak

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Aging, in general, refers to changes in rheological characteristics of asphalt mixture due to changes in chemical composition over the course of construction and service life of the pavement. The main goal of this study was to investigate the impact of oxidation on fatigue characteristics of a novel HMA composite fabricated with a combination of crumb rubber (CRM) and polyvinyl alcohol (PVA) fiber subject to aging of 7 and 14 days. A flexural beam fatigue test was performed to evaluate several characteristics of control, CRM modified, PVA reinforced, and novel rubber-fiber HMA composite. Experimental results revealed that aging had a significant impact on the fatigue performance of novel HMA composite. It was found that a suitable proportion of CRM and PVA radically affected the performance of novel rubber-fiber HMA in resistance to fracture and fatigue cracking when subjected to long-term aging. The developed novel HMA composite containing 2% CRM and 0.2% PVA presented around 29 times higher resistance to fatigue cracking for a period of 7 days of aging. To develop a cumulative plastic deformation level of 250 micros, such a mixture required over 50 times higher cycles than control HMA. Moreover, the crack propagation rate was reduced by over 90%, with over 12 times higher energy required to propagate a unit crack length in such a mixture compared to conventional HMA. Further, digital imaging correlation analyses revealed a more twisted and convoluted fracture path and higher strain distribution in rubber-fiber HMA composite. The fatigue performance after long-term aging of such novel HMA composite explicitly validates the ability to withstand load repetition that could lead to an extension in the service life of pavement infrastructure and reduce taxpayers’ dollars spent.

Keywords: crumb rubber, PVA fibers, dry process, aging, performance testing, fatigue life

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Authors: S. Redjala, N. Ait Hocine, M. Gratton, N. Poirot, R. Ferhoum, S. Azem

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Polycarbonate (PC) is a promising polymer with high transparency in the range of the visible spectrum and is used in various fields, for example medical, electronic, automotive. Its low weight, chemical inertia, high impact resistance and relatively low cost are of major importance. In recent decades, some materials such as metals and ceramics have been replaced by polymers because of their superior advantages. However, some characteristics of the polymers are highly modified under the effect of ultraviolet (UV) radiation and temperature. The changes induced in the material by such aging depend on the exposure time, the wavelength of the UV radiation and the temperature level. The UV energy is sufficient to break the chemical bonds leading to a cleavage of the molecular chains. This causes changes in the mechanical, thermal, optical and morphological properties of the material. The present work is focused on the study of the effects of aging under ultraviolet (UV) radiation and under different temperature values on the physical-chemical and mechanical properties of a PC. Thus, various investigations, such as FTIR and XRD analyses, SEM and optical microscopy observations, micro-hardness measurements and monotonic and cyclic tensile tests, were carried out on the PC in the initial state and after aging. Results have shown the impact of aging on the properties of the PC studied. In fact, the MEB highlighted changes in the superficial morphology of the material by the presence of cracks and material de-bonding in the form of debris. The FTIR spectra reveal an attenuation of the peaks like the hydroxyl (OH) groups located at 3520 cm-1. The XRD lines shift towards a larger angle, reaching a maximum of 3°. In addition, Vickers micro-hardness measurements show that aging affects the surface and the core of the material, which results in different mechanical behaviours under monotonic and cyclic tensile tests. This study pointed out effects of aging on the macroscopic properties of the PC studied, in relationship with its microstructural changes.

Keywords: mechanical properties, physical-chemical properties, polycarbonate, UV aging, temperature aging

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Authors: Saadet Akbay, Ayşe Nihan Avcı

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The perception of colour is a subjective experience which depends on age, gender, race, cultural and educational backgrounds, etc. of an individual. However, colour perception is also affected by the correlated colour temperature (CCT) of a light source which is considered as one of the most fundamental quantitative lighting characteristics. This study focuses on evaluating colour perception in different CCT of light emitting diodes (LED) lighting. The aim is to compare the inherent colours with the perceived colours under two CCT of ‘warm’ (2700K), and ‘cool’ (4000K) LED lights and to understand how different CTT affect the perception of a colour. Analysis and specifications of colour attributes are made with Natural Colour System (NCS) which is an international colour communication system. The outcome of the study reveals the possible tendencies for perceived colours under different illuminance levels of LED lighting.

Keywords: colour perception, correlated colour temperature, inherent and perceived colour, LED lighting, natural colour system (NCS)

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Authors: Roongtiwa Chobchuen, Siriporn Mongkholthawornchai, Boonsong Hatawaikarn, Uriwan Chaichangreet, Kobkaew Thongtid, Pusda Pukdeekumjorn, Panita Limpawattana

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Background: Age-friendly nursing service system in Srinagarind Hospital has been developed continuously based on the value and cultural background of Thailand which corporates with the modified WHO’s Age friendly Primary Care Service System. It consists of 3 issues; 1) development of staff training, 2) age-friendly service and 3) appropriate physical environment. Objective: To evaluate the efficacy of Age-friendly Nursing Service System: KKU (AFNS:KKU) model and to evaluate factors associated with nursing perception with AFN:KKU. Study design: Descriptive study Setting: 31 wards that served older patients in Srinagarind Hospital Populations: Nursing staff from 11 departments (31 wards) Instrument: Age-friendly nursing care scale as perceived by hospitalized older person Procedure and statistical analysis: All participants were asked questions using age-friendly nursing care scale as perceived by hospitalized older person questionnaires. Descriptive statistics and multiple logistic regression analyses were used to analyse the outcomes. Results: There were 337 participants recruited in this study. The majority of them were women (92%) with the mean ages of 29 years and 77.45% were nurse practitioners. They had average nursing experiences of 5 years. The average scores of age-friendly nursing care scale were high and highest in the area of attitude and communication. Age, sex, educational level, duration of work among, and having experience in aging training were not associated with nursing perception where type of department was an independent factor. Nurses from department of Surgery and Orthopedic, Eye and ENT, special ward and Obstetrics and Gynecological had significant greater perception than nurses from Internal Medicine Department (p < 0.05). Conclusion: Nurses had high scores in all dimensions of age-friendly concept. The result indicates that nurses have good attitude to aging care which can lead to improve quality of care. Organization should support other domains of ageing care to achieve greater effectiveness in geriatric care.

Keywords: age-friendly, nursing service system, excellence model, geriatric care

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Authors: Navid Zanganeh, Hafez Balavi, Farbod Sharif, Mahla Zabet, Marzieh Bakhtiary Noodeh

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Cerium oxide (CeO2) also known as cerium dioxide or ceria is a pale yellow-white powder with various applications in the industry from wood coating to cosmetics, filtration, fuel cell electrolytes, gas sensors, hybrid solar cells and catalysts. In this research, attempts were made to synthesize and characterization of CeO2 nano-particles via sol-gel method. In addition, the effect of aging time on the size of particles was investigated. For this purpose, the aging times adjusted 48, 56, 64, and 72 min. The obtained particles were characterized by x-ray diffraction spectroscopy (XRD), scanning electron microscopy (SEM), transmitted electron microscopy (TEM), and Brunauer–Emmett–Teller (BET). As a result, XRD patterns confirmed the formation of CeO2 nanoparticles. SEM and TEM images illustrated the nano-particles with cluster shape, spherical and a nano-size range which was in agreement with XRD results. The finest particles (7.3 nm) was obtained at the optimum condition which was aging time of 48 min, calcination temperature at 400 ⁰C, and cerium concentration of 0.004 mol. Average specific surface area of the particles at optimum condition was measured by BET analysis and recorded as 47.57 m2/g.

Keywords: aging time, CeO2 nanoparticles, size distribution, sol-gel

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Authors: Chia-Jung Li, Kuan-Hao Tsui

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As women age, the quality of their oocytes deteriorates irreversibly, leading to reduced fertility. To better understand the role of Ferroptosis-related genes in ovarian aging, we employed a multi-omics analysis approach, including spatial transcriptomics, single-cell RNA sequencing, human ovarian pathology, and clinical biopsies. Our study identified excess lipid peroxide accumulation in aging germ cells, metal ion accumulation via oxidative reduction, and the interaction between ferroptosis and cellular energy metabolism. We used multi-histological prediction of ferroptosis key genes to evaluate 75 patients with ovarian aging insufficiency and then analyzed changes in hub genes after supplementing with DHEA, Ubiquinol CoQ10, and Cleo-20 T3 for two months. Our results demonstrated a significant increase in TFRC, GPX4, NCOA4, and SLC3A2, which were consistent with our multi-component prediction. We theorized that these supplements increase the mitochondrial tricarboxylic acid cycle (TCA) or electron transport chain (ETC), thereby increasing antioxidant enzyme GPX4 levels and reducing lipid peroxide accumulation and ferroptosis. Overall, our findings suggest that supplementation intervention significantly improves IVF outcomes in senescent cells by enhancing metal ion and energy metabolism and enhancing oocyte quality in aging women.

Keywords: multi-omics, nutrients, ferroptosis, ovarian aging

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Authors: Rachid El Aidani, Phuong Nguyen-Tri, Toan Vu-Khanh

Abstract:

The filter media in synthetic fibre is the most geotextile materials used in aerosol and drainage filtration, particularly for buildings soil reinforcement in civil engineering due to its appropriated properties and its low cost. However, the current understanding of the durability and stability of this material in real service conditions, especially under severe long-term conditions are completely limited. This study has examined the effects of the chemical aging of a filter media in polyester non-woven under different temperatures (50, 70 and 80˚C) and pH (2. 7 and 12). The effect of aging conditions on mechanical properties, morphology, permeability, thermal stability and molar weigh changes is investigated. The results showed a significant reduction of mechanical properties in term of tensile strength, puncture force and tearing forces of the filter media after chemical aging due to the chemical degradation. The molar mass and mechanical properties changes in different temperature and pH showed a complex dependence of material properties on environmental conditions. The SEM and AFM characterizations showed a significant impact of the thermal aging on the morphological properties of the fibers. Based on the obtained results, the lifetime of the material in different temperatures was determined by the use of the Arrhenius model. These results provide useful information to better understand phenomena occurring during chemical aging of the filter media and may help to predict the service lifetime of this material in real used conditions.

Keywords: nonwoven membrane, chemical aging, mechanical properties, lifetime, filter media

Procedia PDF Downloads 318

Authors: Mohammad Ahmad Ahmad Odah

Abstract:

Aging is a complex biological process characterized by the progressive decline of physiological functions and increased vulnerability to age-related diseases. Epigenetic changes, particularly DNA methylation alterations, play a critical role in the aging process by influencing gene expression and genomic stability. This study explores the potential of epigenetic reprogramming as a strategy to reverse aging phenotypes in human fibroblasts. Using CRISPR-Cas9 gene editing and small molecule inhibitors targeting DNA methylation and histone acetylation, we successfully induced significant changes in DNA methylation and gene expression profiles. Our results demonstrate a global reduction in DNA methylation levels and the identification of differentially methylated regions (DMRs) associated with cellular senescence and DNA repair. Additionally, treated fibroblasts exhibited enhanced proliferative capacity, reduced cellular senescence, and improved differentiation potential. These findings suggest that epigenetic reprogramming could be a promising approach for regenerative medicine, offering potential therapeutic strategies to counteract age-related decline and extend healthy lifespan.

Keywords: epigenetic reprogramming, aging, regenerative medicine, DNA methylation, cellular rejuvenation, CRISPR-Cas9, senescence

Procedia PDF Downloads 36

Authors: Rachid El Aidani, Phuong Nguyen-Tri, Toan Vu-Khanh

Abstract:

The filter media in synthetic fibre is the most geotextile materials used in aerosol and drainage filtration, particularly for buildings soil reinforcement in civil engineering due to its appropriated properties and its low cost. However, the current understanding of the durability and stability of this material in real service conditions, especially under severe long-term conditions are completely limited. This study has examined the effects of the chemical aging of a filter media in polyester nonwoven under different temperatures (50, 70 and 80˚C) and pH (2. 7 and 12). The effect of aging conditions on mechanical properties, morphology, permeability, thermal stability and molar weigh changes is investigated. The results showed a significant reduction of mechanical properties in term of tensile strength, puncture force and tearing forces of the filter media after chemical aging due to the chemical degradation. The molar mass and mechanical properties changes in different temperature and pH showed a complex dependence of material properties on environmental conditions. The SEM and AFM characterizations showed a significant impact of the thermal aging on the morphological properties of the fibres. Based on the obtained results, the lifetime of the material in different temperatures was determined by the use of the Arrhenius model. These results provide useful information to better understand phenomena occurring during chemical aging of the filter media and may help to predict the service lifetime of this material in real used conditions.

Keywords: nonwoven membrane, chemical aging, mechanical properties, lifetime, filter media

Procedia PDF Downloads 348

Authors: Sari K. Ishii

Abstract:

This study considers a wider viewpoint to connect migration studies with questions about financial capitalism, which seeks cheap, disposable labour transnationally. This study offers insight into whether the current state of immigration acceptance contributes to stabilizing the aging society of the nation in the long term or merely fulfills the ephemeral requirements of industries. The analyses in this study focused on three aspects. First, it examined how many migrants in Japan joined the labour market. Second, it analyzed the number of migrants that are aging. Third, it determined the number of dependent migrants accepted through labour migrants. The study findings raise further questions for future empirical studies to verify the schema of financial capitalism through the lens of migration. The scheme of seeking cheap, disposable labour transnationally may result in the descendants of both locals and mobilized labour becoming more unstable than the prior generations.

Keywords: migration, aging society, low fertility rate, Japan

Procedia PDF Downloads 42

Authors: U. Chattaraj, K. Dhusiya, M. Raviteja

Abstract:

Perception reaction time of drivers is an outcome of human thought process, which is vague and approximate in nature and also varies from driver to driver. So, in this study a fuzzy logic based model for prediction of the same has been presented, which seems suitable. The control factors, like, age, experience, intensity of driving of the driver, speed of the vehicle and distance of stimulus have been considered as premise variables in the model, in which the perception reaction time is the consequence variable. Results show that the model is able to explain the impacts of the control factors on perception reaction time properly.

Keywords: driver, fuzzy logic, perception reaction time, premise variable

Procedia PDF Downloads 304