Orientation Factor Research Articles

Enhancing corrosion resistance of Al50Ni50 alloy by increasing cooling rate plus annealing

Monophasic Al50Ni50 ribbons were fabricated by melt spinning at circumferential speeds (Sc) of 21 and 42 m/s, and subsequently annealed at various temperatures. The microstructure and corrosion behavior of ribbons were studied through various experimental methods. With increasing Sc, the as-spun and annealed ribbons at 42 m/s show a higher (100) crystal orientation factor F(100), a lower barrier to recrystallization and a higher total film resistance than the counterparts with 21 m/s. The as-spun ribbon at 42 m/s demonstrated a denser and more stable Al2O3 passive film compared to the as-spun and annealed ribbons at 21 m/s. This improvement in passive film can be further enhanced by 700 °C annealing. Therefore, the corrosion resistance of AlNi ribbons can be improved by increasing Sc and additional annealing at an appropriate temperature.

Enhanced persistent orientation of asymmetric-top molecules induced by cross-polarized terahertz pulses

We investigate the persistent orientation of asymmetric-top molecules induced by time-delayed THz pulses that are either collinearly or cross polarized. Our theoretical and numerical results demonstrate that the orthogonal configuration outperforms the collinear one, and a significant degree of persistent orientation—approximately 10% at 5 K and nearly 3% at room temperature—may be achieved through parameter optimization. The dependence of the persistent orientation factor on temperature and field parameters is studied in detail. The proposed application of two orthogonally polarized THz pulses is both practical and efficient. Its applicability under standard laboratory conditions lays a solid foundation for future experimental realization of THz-induced persistent molecular orientation. Published by the American Physical Society 2024

Research on the conductivity and self-sensing properties of high strength cement-based material with oriented copper-coated steel fibers

In this paper, a cement-based sensor for monitoring the performance of high-strength concrete was prepared by adding 0.5 vol%, 1.0 vol%, 1.5 vol%, and 2.0 vol% copper-coated steel fibers (CCSF) as conductive fillers. The fresh cement-based mixture was poured into a funnel-type fiber alignment device, which used its fluidity of the mixture to achieve an aligned distribution of shear-induce fiber within the cementitious matrix. The analysis results indicate that the cement-based sensor with fiber oriented distribution exhibits enhanced electrical conductivity and lower percolation threshold. In addition, the aligned CCSF in the cement matrix mitigates the impact of temperature on resistivity. The resistivity and temperature of the copper-coated steel fibers cement-based sensors (CSFCS) between 5 °C and 70 °C conform to the Arrhenius relationship. The specimens with aligned fibers demonstrate greater flexural strength compared to those with randomly distributed fibers. Additionally, they also reflect greater piezoresistive response, including higher sensitivity, better repeatability as well as less hysteresis time. Through the two-dimensional cross-section analysis, the angle between CCSF and the cross-section of the fiber-aligned specimen is significantly reduced, and the fiber orientation factor and fiber orientation coefficient increased considerably. The funnel device for preparing fiber-reinforced cement-based materials can effectively improve fiber orientation.

Analysis of stress state and crack initiation time around hard-brittle particles in nickel-based alloys by interface model

The finite element method was used to simulate the stress distribution around hard-brittle particles with different particle-matrix interface states in nickel-based alloy with different sample thicknesses under 760 ℃/357 MPa and 980 ℃/250 MPa. The cohesive interface model was used to simulate different particle-matrix interface states. The effects of particle-matrix interface states, geometric characteristics of particles, particle positions in the sample, matrix orientation, and other factors on stress distribution were summarized. Through a thorough analysis of the stress distribution surrounding the particles, the crack initiation time was calculated. The results showed that the maximum stress around the particles was greater when the interface was in completely de-bonded CD state (no binding force between particles and the matrix) compared to the completely bonded CB state (completely coherent between particle and matrix). Furthermore, when the interface was CD, the larger the aspect ratio of the particles, and the closer they were to the surface of the sample, the greater the maximum stress around the particles. When the interface stiffness was reduced (due to mismatch or damage), the stress distribution did not change significantly under high interface stiffness conditions. However, when the interface stiffness decreased to a certain extent, the maximum stress value rapidly increased. In addition, the stress concentration factor began to change when the ratio of sample thickness to particle size (ξ) was less than 5. When the interfacial bonding was weak (with low interface stiffness), the crack initiation time around particles with large aspect ratio decreased significantly with the decrease of interface stiffness. Compared with the condition of 760℃/357 MPa (the same ratio of load to yield strength at 980℃), the crack initiation time around the particle was shorter at 980℃/250 MPa, and the influence of particle geometric features was smaller.

The severity of andropause symptoms and its relationship with social well-being among retired male nurses: a preliminary cross-sectional study

BackgroundAndropause is a syndrome that occurs due to decreased androgen levels in men. Various aspects of health, such as social well-being, can affect andropause status during men’s retirement. This study aimed to determine the severity of andropause symptoms and its relationship with social well-being among retired male nurses.MethodsThis preliminary cross-sectional study was conducted on 284 retired male nurses in Ardabil (northwest of Iran). The participants were selected through the census sampling method. Data were collected using a demographic information form, the Male Andropause Symptoms Self-Assessment Questionnaire (MASSQ), and the Social Well-Being Scale (SWBS). Data were analyzed using SPSS software (version 22.0).ResultsThe study found that the overall mean scores of the severity of andropause symptoms and social well-being among retired male nurses were 57.24 ± 12.62 (range = 35–91) and 94.54 ± 12.77 (range = 75–123), respectively. The highest and lowest mean scores between dimensions of social well-being were related to social contribution (20.26 ± 2.47) and social acceptance (15.26 ± 2.77), respectively. Multiple linear regression analysis revealed that subscales of social well-being, age, marital status, and spouse’s menopause were predictors of the severity of andropause symptoms among retired male nurses. The selected predictors accounted for 53.1% of the total variance in severity of andropause symptoms (F = 36.613, p < 0.001).ConclusionThe results showed a moderate to severe prevalence of andropause among retired male nurses and a significant association between andropause and social well-being. The study suggests further research to examine sexual orientation and other factors that may affect andropause in retired male nurses.

KOMUNIKASI KELUARGA: BAGAIMANA ORANG TUA BERINTERAKSI DENGAN ANAK GEN Z

Harmonious communication and interaction are needed in the family. However, communication is not always good. There are many obstacles faced by parents, especially those who have Generation Z (Gen Z) children. For this reason, there is a need for education for parents in Ciomas Rahayu Village, Ciomas District. Bogor Regency. This is because there are many complaints from parents when communicating with Gen Z children. Parents feel that their children prefer gadgets rather than activities with the environment and family. Education by providing materials, discussions and questions and answers as well as simulations made parents understand how to communicate with Gen Z children. Participants were also shown videos about healthy internet and education with games so they understood the material presented. From the material presented, discussions and simulations carried out, parents who have Gen Z children understood how to behave and communicate with their children. Parents do not always give advice or improve conversation orientation factors, but a warm conformity orientation approach in a relaxed atmosphere and not dominating one member over another is effective in changing children's negative attitudes.

Direct numerical simulations of a novel device to fight airborne virus transmission

The SARS-CoV-2 (COVID-19) pandemic has highlighted the crucial role of preventive measures in avoiding the spread of disease and understanding the transmission of airborne viruses in indoor spaces. This study focuses on a novel personal protective equipment consisting of a fan-peaked cap that creates a jet flow of air in front of the individual's face to reduce the concentration of airborne viruses and decrease the risk of infection transmission. Direct numerical simulation is used to analyze the effectiveness of the device under certain conditions, such as the velocity of the airflow, flow orientation, ambient conditions, and geometrical factors.

Effects of Polybutylene Succinate Content on the Rheological Properties of Polylactic Acid/Polybutylene Succinate Blends and the Characteristics of Their Fibers.

Polylactic acid (PLA) and polybutylene succinate (PBS) are gaining prominence as environmentally friendly alternatives to petroleum-based polymers due to their inherent biodegradability. For their textile applications, this research is focused on exploring the effects of PBS content on the rheological properties of PLA/PBS blends and the characteristics of PLA/PBS blend fibers. PLA/PBS blends and fibers with varying PBS contents (0 to 10 wt.%) were prepared using melt-blending and spinning methods. Uniform morphologies of the PLA/PBS blends indicated that PBS was compatible with PLA, except at 10% PBS content, where phase separation occurred. The introduction of PBS reduced the complex viscosity of the blends, influencing fiber properties. Notably, PLA/PBS fibers with 7% PBS exhibited improved crystallinity, orientation factor, and elasticity (~16.58%), with a similar tensile strength to PLA fiber (~3.58 MPa). The results suggest that an optimal amount of PBS enhances alignment along the drawing direction and improves the molecular motion in PLA/PBS blend fiber. This study highlights the potential of strategically blending PBS to improve PLA fiber characteristics, promising advancement in textile applications.

A strategy for low thermal conductivity of lutetium oxyorthosilicate ceramics fabricated via texture engineering

AbstractSubmicrometer lutetium‐gadolinium oxyorthosilicate ((Lu0.95Gd0.05)2SiO5, LGSO) powder with a magnetic susceptibility of 4.19 10−6 (5.4 times that of lutetium oxyorthosilicate) was synthesized via a sol‐gel method. Slip casting with a 6 T assisted magnetic field and pressureless sintering at 1600°C for 16 h in the air effectively produced the textured LGSO ceramics with an orientation factor f of 0.96. The grains of textured LGSO ceramics grow with the preferred orientation along the b‐axis. The thermal conductivity of the textured LGSO ceramics reaches only 2.05 W·m−1·K−1 at 300 K, which is 34.5% lower than that of untextured LGSO ceramics. Textured LGSO ceramics provide increased fracture toughness. This work presents a microstructural design method for RE2SiO5 ceramics to regulate thermal and mechanical properties through texture engineering, as well as advice for the selection or optimization of RE2SiO5 ceramics as a Thermal Barrier Coatings (TBCs) material.

Sex and gender correlates of sexually polymorphic cognition

BackgroundSexually polymorphic cognition (SPC) results from the interaction between biological (birth-assigned sex (BAS), sex hormones) and socio-cultural (gender identity, gender roles, sexual orientation) factors. The literature remains quite mixed regarding the magnitude of the effects of these variables. This project used a battery of classic cognitive tests designed to assess the influence of sex hormones on cognitive performance. At the same time, we aimed to assess the inter-related and respective effects that BAS, sex hormones, and gender-related factors have on SPC.MethodsWe recruited 222 adults who completed eight cognitive tasks that assessed a variety of cognitive domains during a 150-min session. Subgroups were separated based on gender identity and sexual orientation and recruited as follows: cisgender heterosexual men (n = 46), cisgender non-heterosexual men (n = 36), cisgender heterosexual women (n = 36), cisgender non-heterosexual women (n = 38), gender diverse (n = 66). Saliva samples were collected before, during, and after the test to assess testosterone, estradiol, progesterone, cortisol, and dehydroepiandrosterone. Psychosocial variables were derived from self-report questionnaires.ResultsCognitive performance reflects sex and gender differences that are partially consistent with the literature. Interestingly, biological factors seem to better explain differences in male-typed cognitive tasks (i.e., spatial), while psychosocial factors seem to better explain differences in female-typed cognitive tasks (i.e., verbal).ConclusionOur results establish a better comprehension of SPC over and above the effects of BAS as a binary variable. We highlight the importance of treating sex as a biological factor and gender as a socio-cultural factor together since they collectively influence SPC.

Entrepreneurial Orientation Factors of University Graduates in the Cameroonian Context : The Case of the Far North.

Purpose : The objective of this study is to determine the entrepreneurial orientation factors of young university graduates in Cameroon, in a context where businesses evolve in an unstable, unpredictable environment. &#x0D; Methodology : To achieve this objective, an analysis was carried out on exploratory survey data collected from 198 university-educated entrepreneurs in the Far North region of Cameroon, using chi-square independence tests between variables such as gender, education and age to confirm their impact on the orientation of entrepreneurial specialization.&#x0D; Findings : The results of this study showed that only gender and entrepreneurial education appear as factors in entrepreneurial orientation in the present study. While for men, there seems to be no limit to engaging in a particular activity, women do not have this flexibility, as they find it easier to orientate themselves in activities such as trade, hairdressing and catering, but not in activities such as butchery and banking.&#x0D; Unique contribution to theory, practice and policy : Given that the study also shows that, thanks to training, young entrepreneurs have the flexibility to operate in all sectors of activity, particularly those requiring specific knowledge such as health services, it is therefore recommended that Cameroonian public authorities step up the promotion of entrepreneurship training to encourage young people to become self-employed.

Large flakes of Al–Ti3C2Tx MXene constructing highly ordered layered MXene/ANF films with integrated multifunctionalities

The simultaneous realization of high mechanical properties and excellent multifunctional performance for nanocomposite films is still a key challenge for practical applications. In this work, a dilute MXene (Al–Ti3C2Tx)/aramid nanofiber (ANF) dispersion (0.013 wt%) containing large-sized, long-term stable Al–Ti3C2Tx nanosheets (5.58 ± 1.68 μm) and branched ANFs was filtered under vacuum pressure to obtain highly ordered layered Al–Ti3C2Tx/ANF nanocomposite films with different Al–Ti3C2Tx contents (orientation factor: 0.91). Among them, the 40 wt% Al–Ti3C2Tx/ANF film offers the benefits of excellent mechanical properties (strength: 200.79 ± 1.32 MPa, strain-to-failure: 8.05 ± 0.65 %, toughness: 9.96 ± 0.84 MJ/m3), high electrical conductivity (201.6 ± 5.5 S/cm), superior EMI shielding effectiveness of up to 15 264 dB cm2 g−1 in accordance with the theoretical calculation and high electrothermal conversion temperature up to ≈120.7 °C with a rapid response time of 4 s. In addition, the nanocomposite film also boasts a superhydrophobic property with a water contact angle of 162.0 ± 1.6° along with flame retardancy. The inherent properties of 2D materials and their highly ordered arrangement in the polymer matrix are expected to provide a feasible design proposal for preparing all-in-one multifunctional films.

Magnetic Alignment of Micro Steel Fibers Embedded in Self-Compacting Concrete

Steel fiber reinforced cementitious composites (SFRCC) have emerged as one of the most efficient techniques to improve the flexural capacity and ductility performance of concrete. However, one of the most significant shortcomings is the randomness of steel fibers direction in the concrete matrix, which influences the extent of mechanical enhancement for a limited fiber content. An experimental approach to control the direction of steel fibers embedded in self-compacting concrete is presented in this study, which is based on generating a driving rotating force to overcome the viscous impeding forces acting onto the embedded fiber. The mechanical performance of micro steel fiber reinforced self-compacting concrete members was investigated. A uniform magnetic field of 9.8×10-3 Tesla generated by a cylindrical powered coil was capable of aligning micro steel fibers embedded in fresh self-compacting concrete along the desired direction. The testing program included seven beam specimens of size of 100 ×100 x 500 mm3. The micro steel fiber contents considered were 0.35%, 0.70%, and 1.05% by volume. Fiber volume fraction of 0.35% was the optimum dosage for magnetic alignment as it achieved the highest extents of mechanical enhancement. The concrete specimens reinforced with 0.35% of steel fiber content have exhibited enhancement rates of 5%, 28%, and 30% in four-point failure load, maximum mid-span deflection, and compressive strength, respectively. Based on the visual analysis of cross-sectional images, the highest orientation factor achieved was 0.91 when steel fiber dosage was 0.35%, whereas the random non-magnetized steel fiber reinforced beams achieved an orientation factor ranging from 0.30 to 0.50.

The Influence of Emotions and Social Value Orientation on Risk Tolerance and Sustainable Investment Choices

Purpose - The intricacy of the decision-making process has increased due to the inherent uncertainty surrounding investments. Therefore, the study aims to investigate the impact of individuals' Social Value Orientation (SVO), Emotional Instability (EI), and demographic factors on their Financial Risk Tolerance (FRT) levels. Additionally, it aims to investigate whether SVO and EI influence the adoption of socially responsible investment (SRI) funds and the diverse investment choices made by individuals. Methodology - A convenient sampling technique was employed to gather data from 355 Indian retail investors through a structured questionnaire. Subsequently, the collected data was then examined and interpreted using binary logistic regression and chi-square tests facilitated by the SPSS 26 software. Findings - The results emphasize that SVO, EI, Age, Marital status and Gender are significant predictors of investors' FRT. Furthermore, our study unveils that investors with a pro-social mindset are more inclined to invest in SRI funds compared to those who prioritize themselves. Originality – The current study contributes to the existing literature by introducing a novel and unexplored variable, i.e., SVO, for academic consideration in risk tolerance. Moreover, this study imparts a profound understanding of behavioural finance by illuminating the influence of investors' values and emotions on their inclination to embrace risk. Social Implication - By examining investors' preferences and interests in SRI, we gain valuable insight into the growing importance of sustainable funds. This aligns harmoniously with the overarching pursuit of Sustainable Development Goals (SDGs), as these conscientious investment funds scrutinize and eliminate companies that harm society.

Factors Influencing Mathematics Anxiety and Mathematics Performance: A Scoping Review towards Learning Optimization Directives

This scoping review determined the factors contributing to the mathematics anxiety and its effect on the mathematics performance among Filipino high school students. This aimed to describe the extent and nature of the literature on math anxiety and math performance, and to identify gaps to guide future directions in Math teaching and learning optimization in the Philippines. The keywords used to search existing evidence on Google Scholar, PubMed, Scopus, Semantic Scholar, Crossref, and Web of Science databases were mathematics anxiety, mathematics performance, factors, high school, and Philippines. A review of 13 out of 950 published studies in indexed journals from 2014 to 2024, in the English language, were selected for this scoping review using the Joanna Briggs Institute guidelines. Of the 13 included studies, a number of studies were published between 2014-2019 (n=5, 38%) and 2020-2024 (n=8, 62%). There were 10 (77%) quantitative, 1 (8%) qualitative article, and 2 (15%) mixed methods, with sample sizes ranging from 8 to 379. It is concluded that there is an inverse relationship between Math anxiety and Math performance – the higher the math anxiety level, the poorer the math performance. Furthermore, there are multidimensional factors contributing to Math Anxiety and Performance including student factors, teacher factors, home environment and relationship, Learning environment, subject factors, cultural orientation, and Peer factor. Identifying the most common contributory factors is crucial in developing targeted interventions. An evidence-based dedicated learning optimization plan is needed to provide information that will guide the teachers for Math performance enhancements.

&lt;i&gt;x&lt;/i&gt;Fe/Bi&lt;sub&gt;0.5&lt;/sub&gt;Sb&lt;sub&gt;1.5&lt;/sub&gt;Te&lt;sub&gt;3&lt;/sub&gt; thermoelectromagnetic films with coexistence of positive and negative magnetoresistance

Thermoelectric (TE) films with excellent electrical transport property are key materials for developing efficient in-plane heat dissipation technology, but their low electrical transport property is a challenge that restricts their application. Recently, a new thermo-electro-magnetic coupling effect has been proposed to significantly improve the comprehensive TE performance. In order to explore the influence of the above effects on the electric transport property of TE films, we develop an integrated preparation method through ball milling dispersion, screen-printing and hot-pressing curing, obtaining a series of &lt;i&gt;x&lt;/i&gt;Fe/Bi&lt;sub&gt;0.5&lt;/sub&gt;Sb&lt;sub&gt;1.5&lt;/sub&gt;Te&lt;sub&gt;3&lt;/sub&gt; (BST)/epoxy TE films in which Fe nanoparticles serve as the second phase, resulting in the thermo-electro-magnetic coupling effect , and also we study their influence on the electrothermal transport performance. The results are shown below. The positive and negative magnetoresistance are co-existent in &lt;i&gt;x&lt;/i&gt;Fe/BST/epoxy thermoelectromagnetic films; the preferred orientation factor of BST (000&lt;i&gt;l&lt;/i&gt;) is positively proportional to the positive magnetoresistance (MR&lt;sup&gt;+&lt;/sup&gt;), resulting in an increase of the conductivity; the spin-dependent scattering of negative magnetoresistance (MR&lt;sup&gt;–&lt;/sup&gt;) derived from the local magnetic moment of strong ferromagnetic Fe nanoparticles increases the Seebeck coefficient. Hence, the power factor of Fe/BST/epoxy thermoelectromagnetic film near room temperature reaches 2.87 mW⋅K&lt;sup&gt;–2&lt;/sup&gt;⋅m&lt;sup&gt;–1&lt;/sup&gt;, which is 78% higher than that of BST/epoxy thermoelectric film. These results indicate that the coexistence of positive and negative magnetoresistance in thermoelectromagnetic films can not only relieve the coupling relationship between conductivity and Seebeck coefficient in TE materials, but also provide a new physical mechanism for the excellent TE conversion performance induced by magnetic nanoparticles.

Determinants of Sustainable Consumption Intention

Sustainable consumption has received a lot of attention from many regions and countries around the world recently. This study investigates factors that influence consumers' sustainable consumption intentions in Vietnam. Despite the growing importance of sustainable consumption, marketing managers still lack adequate information on how to promote it to consumers. This study aims to address this gap by examining the impact of environmental knowledge, man-nature orientation, environmental advertising, and demographic factors such as income, major, degree, age, and gender on sustainable consumption intention. An online survey was used to collect data from 460 people in Vietnam. The data was processed using multivariate linear regression analysis, Cronbach alpha, ANOVA, and other methods to identify factors affecting sustainable consumption intentions in Vietnam. The results show that man-nature orientation and environmental advertising have a positive impact on sustainable consumption intentions. Furthermore, the study also found a strong relationship between environmental advertising and man-nature orientation as well as natural and environmental knowledge. In contrast, the study did not find a relationship between environmental knowledge and sustainable consumption intentions. These results provide theoretical and practical implications for marketing managers in developing effective communication strategies to promote sustainable consumption and encourage environmentally friendly consumption intentions.

Preparation of Textured Polycrystalline La2NiO4+ δ Membranes and Their Oxygen-Transporting Properties

Due to its high chemical and thermal stability in CO2 atmosphere and its anisotropic crystal structure, the Ruddlesden-Popper phase La2NiO4+δ has attracted considerable attention in the research field of oxygen-transporting membranes. The anisotropic properties of La2NiO4+δ can be exploited in textured polycrystalline membranes to control the oxygen diffusion through this material. To fabricate textured La2NiO4+δ membranes, powder mixtures consisting of fine-grained equiaxial La2NiO4+δ matrix particles and large plate-like La2NiO4+δ template particles in different mass ratios were uniaxially pressed and then sintered in air. For this purpose, the anisotropic template particles were synthesized by molten-flux method using NaOH as flux [1]. In the powder mixture, the La2NiO4+δ template particles can be aligned perpendicular or parallel to the pressing direction, depending on the geometry of the pressing tool and the sample preparation. After the sintering process, textured La2NiO4+δ membranes were obtained, which was verified by measuring X-ray diffraction patterns and pole figures. Further X-ray diffraction measurements together with the calculation of the Lotgering orientation factor revealed that an increasing content of the template particles in the ceramic materials leads to a stronger texturing. Scanning electron microscopy micrographs show some individual plate-like La2NiO4+δ grains well embedded in the matrix. Homogeneous distribution of lanthanum, nickel and oxygen in the ceramics was confirmed by energy-dispersive X-ray spectroscopy. Finally, the influence of the template particle content in the La2NiO4+δ membranes on the oxygen permeation performance is discussed. [1] Escobar Cano, G.; Brinkmann, Y.; Zhao, Z.; Kißling, P.A.; Feldhoff, A. Sol–Gel-Process-Based Molten-Flux Synthesis of Plate-like La2NiO4+ δ Particles. Crystals 2022, 12, 1346. https://doi.org/10.3390/cryst12101346

VOLUNTEERING, DISCRIMINATION, AND DEPRESSION IN OLD AGE: DOES THE FORM OF DISCRIMINATION PLAY A ROLE?

Abstract Older adults experiencing discrimination have an increased risk of poor mental health, such as depression. Discrimination could happen based on age, race, gender, sexual orientation, or other factors but the effects of experiencing different forms of discrimination on depression are unknown. Given the evidence that volunteering in old age promotes mental health, this study explores the relationship between volunteering and depressive symptoms among older adults who experience discrimination, and investigates whether such a relationship differs between those experiencing ageism and those experiencing other forms of discrimination. Using a subsample of respondents 65-96 years of age from the 2016 Health and Retirement Study, 1881 older adults who reported experiencing everyday discrimination were included. Discrimination was measured by the six-item Everyday Discrimination Scale. Among them, 955 respondents named age as the reason behind the discrimination experiences, and 926 named other forms (e.g. race). Controlling for health-related variables (e.g., ADLs/IADLs), SES (e.g., income), and sociodemographics (e.g., gender), findings from the weighted OLS regression models showed that volunteering (doing unpaid work for religious, educational, health-related, or other charitable organizations) related to lower depressive symptoms (8-item CES-D, P&amp;lt;.05). When looking at the groups who experienced different forms of discrimination, volunteering continued to have a negative relationship with depressive symptoms for older adults who experienced ageism (p&amp;lt;.01); however, such a relationship disappeared for the group experiencing other forms of discrimination. Discussions will target the importance of understanding the complicated relationships that may exist in volunteering, mental health, and the forms of discrimination that older adults experience.

Micromechanics of Ti3C2Tx MXene reinforced poly(vinyl alcohol) nanocomposites

The key to effective mechanical reinforcement in polymer nancomposites lies within the stress transfer mechanisms and the distribution of the nanofillers within a polymer matrix. In this work, the micromechanics of Ti3C2Tx MXene-reinforced poly(vinyl alcohol) (PVA) nanocomposites have been studied in detail. Ti3C2Tx MXene/PVA nanocomposites were prepared by solution blending. The spatial orientation of Ti3C2Tx MXene in the nanocomposites was characterized by polarized Raman spectroscopy and the orientation factor was correlated to the effective Young's modulus of the flakes through well-established micromechanical theories. The mechanical properties of the nanocomposites were evaluated by tensile testing. A 27% increase in Young's modulus and a 24% improvement in tensile strength were achieved by addition of only 0.6 wt% Ti3C2Tx. Efficient stress transfer from the polymer matrix to Ti3C2Tx MXene in bulk nanocomposites has been observed through strain-induced Raman band shifts for the first time. The effective Young's modulus of the MXene nanoplatelets was calculated to be in the order of 300 GPa, in good agreement with the values derived from the application of micromechanical models.