Demand for particleboards keeps increasing and as such more trees are fell for its production, engendering deforestation. For the purpose of reducing falling of trees, this study, focused on recycling of waste paper in the development of paperboard as alternative to particleboards used for furniture and interior household applications. Kenaf fiber (KF) was blended at varying proportions of 0, 1, 2, 3, 4, and 5 wt.% with 20 wt.% constant cement and 20 wt.% constant coconut shell powder while the remaining was paper pulp. Board specimen developed were cured for 14, 28, and 90 days and mechanical properties were examined. Results obtained showed that fiber dosage improved bond strength and screw holding strengths as compared with the control mix. Similarly, modulus of rupture was enhanced with KF loading as compared with control mix while 1 to 3 wt.% KF spawned enhancement of modulus of elasticity. However, 4 and 5 wt.% KF led to a reduction in the modulus. Infusion of the fiber enhanced tensile strength from 1 to 3 wt.% content. 14-day and 28-day curing periods were observed to improve properties while the 90-day curing period is detrimental to all properties. Optimization via signal-to-noise ratio revealed an optimum mix of 2 wt.% obtained for fiber and an optimum curing duration of 28 days.
相似文献Methods: A cross-sectional survey of risky behavior among undergraduates was conducted. A stratified random sampling method was used to identify young undergraduates who had driven a motorized vehicle in the past year. The Alcohol Use Disorder Identification Test (AUDIT) and other tools developed by researchers were used to identify the risky behaviors.
Results: Of 431 respondents, 10.7% had engaged in drink driving in the past 12 months. The most common risky behavior was making phone calls (63.7%), followed by nonuse of helmets (54.7%), driving against traffic (49.2%), nonuse of seat belts (46.8%), and sending text messages (26.1%). Alcohol use was significantly associated with making phone calls (U = 1.148; P < .0001), sending text messages (U = 1.598; P = .021), nonuse of helmets (U = 1.147; P < .0001), driving against traffic (U = 1.234; P < .0001), and nonuse of seat belts (U = 3.233; P = .001). Drink driving was associated with all risky behaviors except nonuse of seat belts (U = 1.842; P = .065).
Conclusion: Alcohol use and drink driving were associated with multiple risky driving behaviors. This provides useful insight for policy development and presents additional challenges for traffic injury prevention. 相似文献