RESUMEN
In this paper, an efficient procedure for ripeness detection of watermelon was presented. A nondestructive method was used based on vibration response to determine the internal quality of watermelon. The responses of samples to vibration excitation were optically recorded by a Laser Doppler (LD) vibrometer. Vibration data was collected from watermelons of two qualities, namely, ripe and unripe. Vibration signals were transformed from time-domain to frequency-domain by fast Fourier transform (FFT). Twenty nine features were extracted from the FFT amplitude and phase angle of the vibration signals. K-nearest neighbor (KNN) analysis was applied as a classifier in decision-making stage. The experimental results showed that the usage of the FFT amplitude of the vibration signals gave the maximum classification accuracy. This method allowed identification at a 95.0 % level of efficiency. Hence, the proposed method can reliably detect watermelon ripeness.
RESUMEN
The present study investigates the phenomena of creep in a bamboo composite. The material was tested under tensile and compressive loading and simulated in finite element analysis software to estimate the creep coefficients. The presented findings have displayed the material's propensity to fail at loads lower than the recorded ultimate strength, as early as 65% of this strength within 100 h, showing the importance of considering creep when designing structural components. Larger resistance to creep was observed under tensile stresses. Coefficients of the time-hardening creep model were estimated, which were found to be different under compression and tension. The findings provide insight into the reliable strength value of the Bamboo Composite. They could be also essential in estimating the long-term deflations in Bamboo Composite structures.
RESUMEN
Parallel strand bamboo is a composite material that demonstrates high strength and low variability compared to other timber materials. However, its use in bolted connections is limited by a tendency to fail in shear-out mode. One promising technique to prevent failure is the method of confinement, whereby the composite connection is confined laterally, inducing a compressive force perpendicular to the composite fibres, which increases the shear strength in the loading process. This paper investigates the confinement method and its effect on parallel strand bamboo connections' strength and failure mechanisms through experimental tests and ANSYS simulation methods. It was discovered that bolted connection confinement reduces the propensity of shear-out failure by counteracting shear stresses. A comparison of graphical results revealed that confinement increased the ultimate tensile capacity of parallel strand bamboo bolted connections by up to 26%. Confinement also improved the consistency of the connection's mechanical properties throughout the loading process. These findings assist in refining and optimising practical applications of parallel strand bamboo connections by using the method of connection confinement.
RESUMEN
Improving the environmental impact is a critical factor in achieving sustainable development in agricultural systems. To achieve this goal, the environmental assessment of agricultural products to identify environmental hot-spots and provide strategies for reducing them is essential. In line with that, the current study is performed to assess the environmental impacts of Primrose greenhouse production in Savojbolagh County, Iran. More specifically, the environmental impacts of Primrose greenhouse production based on the cradle to gate analysis using the life cycle assessment approach are evaluated. According to results, production and combustion of diesel fuel are introduced as the environmental hotspot in non-carcinogens, respiratory inorganics, respiratory organics, terrestrial acid/nutri, aquatic acidification, global warming, and non-renewable energy impact categories. The application of pesticides and fertilizers in the greenhouse has the highest contribution in aquatic ecotoxicity as well as terrestrial ecotoxicity impact categories. Moreover, electricity consumption has the highest impact on carcinogens, and ozone layer depletion impact categories. Based on the outcomes of the life cycle assessment approach, the production of a piece of Primrose leads to damages of 1.48 × 10-7 DALY (disability-adjusted life year) and 3.41 × 10-1 PDF.m-2.yr-1 (potentially disappeared fraction in square-meters per year) to human health and ecosystem quality, respectively. In addition, the production of each Primrose plant results in primary damages of 2.06 × 10-1 kg CO2eq. (equivalent carbon dioxide) and 2.94 MJ (Megajoule) to climate change and resources, respectively. Finally, the weighing of environmental impacts based on IMPACT 2002+ methods shows that the ecosystem quality damage category has a share of 30% in total environmental impacts of one piece of Primrose production. Damages to ecosystem quality are mostly caused by pesticide and fertilizer applications in Primrose greenhouse. Accordingly, it could be concluded that correct management of pesticides and fertilizers can potentially mitigate environmental impacts of Primrose production in a greenhouse.