Personality Type and Perceived Quality of Life of Selected College Students

The World Health Organization declared the COVID-19 outbreak as a global pandemic, in which many countries began implementing restrictions to control the virus. As a result, it began to disrupt the normal activities of people around the world, including college students. Limited studies have been done in relation to this topic; thus, this study aimed to determine the significant difference in the perceived quality of life of selected college students across personality types during the pandemic. This study utilized Descriptive-Evaluative and Descriptive-Comparative research designs. Researchers purposively sampled 123 respondents from eight colleges in a selected university in Silang, Cavite. Respondents answered a self-reported online questionnaire including a personality temperament test and perceived quality of life. Data were analyzed using statistical tests of Mean, Standard Deviation, and ANOVA. Results revealed that choleric has the highest frequency of 51 (41.5%) among the four-personality types. The overall perceived quality of life was fairly high, with a mean of 4.62 (SD = 1.19). The level of satisfaction that the respondents get from receiving help from friends and family was high, with the highest mean score of 5.30 (SD = 1.53). Moreover, the result showed that there is a significant difference in the perceived quality of life across personality types (p = .30). Choleric has a significantly higher perceived quality of life than Sanguine (p = .051). Among the moderating variables, none had a significant difference in the perceived quality of life of the respondents. For future studies, quality of life and personality type among college students comparing both remote learning and in-person learning can be done.Keywords: Personality, Quality of Life, College Student

Differentiation of non-black fillers in rubber composites using linear discriminant analysis of principal components

In the compounding of rubber composites, different non-black fillers are used to improve the physical properties, reduce the formulation cost, and provide special characteristics. Designing a rubber composite for a specific application needs the careful selection and differentiation of fillers based on its effect on processibility and overall material properties of the vulcanizate. However, fillers are usually classified according to their effect on reinforcement or function without much consideration to other properties such as vulcanization characteristics and heat aging resistance. Analyses of multiple properties are tedious when done in a univariate way. To differentiate non-black fillers with consideration to the various properties of rubber composites, linear discriminant analysis (LDA) of principal components (PCs) was used. This paper examines how vulcanization and mechanical properties can differentiate aluminosilicate, bentonite, and silica fillers in rubber composites

Differentiation of non-black fillers in rubber composites using linear discriminant analysis of principal components

AbstractIn the compounding of rubber composites, different non-black fillers are used to improve the physical properties, reduce the formulation cost, and provide special characteristics. Designing a rubber composite for a specific application needs the careful selection and differentiation of fillers based on its effect on processibility and overall material properties of the vulcanizate. However, fillers are usually classified according to their effect on reinforcement or function without much consideration to other properties such as vulcanization characteristics and heat aging resistance. Analyses of multiple properties are tedious when done in a univariate way. To differentiate non-black fillers with consideration to the various properties of rubber composites, linear discriminant analysis (LDA) of principal components (PCs) was used. This paper examines how vulcanization and mechanical properties can differentiate aluminosilicate, bentonite, and silica fillers in rubber composites.Aluminosilicate and silica were effectively differentiated frombentonite using the vulcanization characteristics and mechanical properties of rubber composites before heat aging. Better differentiation among the 3 non-black fillers was achieved when the mechanical properties of rubber composites after heat aging were included in the PC analysis. LDA required at least 6 PCs to correctly classify the non-black filler in 30 rubber composites.</jats:p

Effect of Ingredient Loading on Water Transport Properties of a Vulcanized Natural Rubber Compound

Water transport properties of a vulcanized natural rubber compound are studied as function of ingredient loading using gravimetric method at 800C. Rubber sheets are compounded according to a fractional factorial design of experiment, where ingredients are treated as factors varied at two levels of loading. Weight change during immersion in water is monitored. The maximum uptakes are determined from the sorption curves which showed two distinct slopes of which two uptake rates are estimated. Analysis of variance shows that high loadings of sulfur, asphalt, and used oil significantly increase the maximum uptake and first uptake rate while only sulfur and asphalt significantly increase the second uptake rate. On the other hand, high loadings of reclaimed rubber, calcium carbonate (CaCO3), mercaptobenzothiazole (MBT) significantly decrease the maximum amount of water uptake. Similarly, high loading of mercaptobenzothiazole disulfide (MBTS) significantly decrease the initial uptake rate while high loadings of reclaimed rubber, CaCO3, kaolin clay, and MBT decrease the final uptake rate of rubber compounds.</jats:p

Correlation of Blooming and Tensile Properties in Surfactant-Loaded Natural Rubber Vulcanizates

Tensile properties of surfactant-loaded natural rubber (NR) vulcanizates are investigated in correlation with blooming. Rubber sheets are compounded using an L12 orthogonal array of Taguchi design of experiment, where ingredients are treated as factors varied at low and high loadings. Blooming experiments are carried out by placing NR sheets in a natural convection oven set at 50 °C for 20 days. The amount of bloom on the surface is removed using adhesive tape and is monitored with time. Tensile properties of rubber dogbone samples are also measured with time. Results show that 5 out of 12 formulations show blooming to be significantly related to tensile modulus (0.005 &lt; p &lt; 0.039). It is observed that the tensile modulus increases with blooming (0.898 &lt; r &lt; 0.973). Three formulations indicate significant correlation of blooming with tensile strength (0.022 &lt; p &lt; 0.047). As observed, tensile strength decreases with blooming (-0.884 &lt; r &lt; -0.930). Five formulations signify blooming to have significant correlation with maximum tensile strain (0.000 &lt; p &lt; 0.011), which decreases with blooming (-0.957 &lt; r &lt; -0.995). Two formulations imply significant negative (-0.960 &lt; r &lt; -0.963) correlation between blooming and tensile set (p= 0.009).</jats:p

Effect of Silane-Treated Wollastonite on Mechanical and Thermal Properties of 3D-Printed ABS via Fused Deposition Modeling

The effect of the addition of epoxysilane-treated wollastonite (ETW) to the mechanical and thermal properties of 3D-printed acrylonitrile butadiene styrene (ABS) via fused deposition modeling (FDM) was investigated. The loading of ETW was varied at 1, 3, and 5wt%. The 3D-printed composites were evaluated by scanning electron microscopy (SEM) tensile test, shore D hardness, differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The addition of ETW increases the tensile strength, elastic modulus, and toughness of ABS by up to 46.6, 56.2, and 53.7 %, respectively. The shore D hardness increases with increasing ETW. Morphological analysis show that this improvement in mechanical properties is a result of the high aspect ratio of the fillers, the uniform dispersion of ETW in the ABS matrix, and the orientation of ETW particles toward the direction of tensile stress. The glass transition temperature (Tg) of the composites increases and the onset of degradation slightly shifted to higher temperature with an increase in filler loading. The addition of ETW to ABS matrix in FDM 3D printing improved the mechanical and thermal properties of ABS.</jats:p

Feasibility of oxidized soybean oil for rubber devulcanization

Abstract This study investigates the feasibility of using oxidized soybean oil (Ox-SO) for mechano-chemical devulcanization of sulfur-cured natural rubber. A 22 full factorial design of experiment was used to determine the effect of devulcanization time (20, 40 min) and amount of Ox-SO (6, 10 phr) in the crosslink density and sol-gel content of devulcanized VR (DVR). After conductive heating and stirring of soybean oil for 60 h, a peroxide value of 316.3 meq O2 kg−1 oil was achieved which corresponds to approximately 2500 ppm of lipid hydroperoxides. Decreasing the devulcanization time (from 40 to 20 min) and amount of Ox-SO (from 10 to 6 phr) decreased the crosslink density by 71.1% and increased the sol content by 228.2%. The optimum conditions are 20 min of devulcanization time and 6 phr of Ox-SO where the crosslink density of VR is reduced to 6.2×10−5 mol cm−3 and the sol content is 10.2% (control VR crosslink density: 2.1×10−4 mol cm−3, sol content: 3.1% ). In summary, Ox-SO was found to be a feasible agent for rubber devulcanization. DVR blends with virgin rubber are required to assess Ox-SO’s commercial readiness.</jats:p