This research work intended to study the effect of the scratch with different scratch loads (20, 40, and 60 N) on the drop weight (impulse) impact energy of recycled needle punched natural jute fiber mats reinforced unsaturated polyester composites with 25 Vol.% fiber volume content. The fracture behavior of the above-mentioned composites was also investigated for each case. The results showed that the impact energy of scratched composites was decreased 40% by scratch load 20 N compared to that of virgin specimen and by increasing the scratch load to 40 N the loss in the total impact energy of the composites was decreased to 2% compared to that of the virgin specimen. On the other hand, the total impact energy of the composite was improved to around 10% by increasing the scratch load to 60 N compared to that of the virgin specimen. Moreover, the fracture behavior showed that the radial matrix cracks and more extensive delamination was observed in scratched specimen at a scratch load of 60 N compared to those of the virgin specimen and this leads to dissipate most of the impact energy and so the impact energy of the composites was improved at a scratch load of 60 N compared to that of the virgin specimen.

This study intended to investigate the durability of recycled needle punched natural jute fiber mats with 32 Vol.% fiber volume reinforced unsaturated polyester matrix composites by investigating water absorption and thickness swelling under the effect of hot water absorption at 100oC for 96, 192, 384 h immersion times compared to the virgin specimens. Moreover, the effect of drying of these immersed composites for 6 h at 100oC in a drying oven for different immersion times was investigated. The results showed that as the immersion time of the composites increases, the water absorbed by the composites increases and so the thickness swelling increases. On the other hand, when the immersed specimens are dried for 6 hours, the water absorption of the composites decrease compared to those of the immersed specimens and therefore the thickness swelling of the composites decreases after the specimens are dried compared to those of the immersed specimens.

Mine developments such as haulage drifts and cross-cuts are the primary access to the mining blocks of an orebody in multilevel mining systems for tabular ore deposits. Thus, their stability is of utmost importance during the planned period of production or the life of a mine plan. Many Canadian underground mines use longitudinal and transverse stoping with delayed backfill to extract tabular ore deposits. These methods require access to the orebody through a number of sill drives or cross-cuts which link the orezone to the haulage drift hence creating intersections on multiple levels. Mine development instability could lead to serious consequences such as injuries, production delays and higher operational cost. The objective of this research is to develop a hybrid approach in which deterministic numerical modelling is integrated with probabilistic methods to evaluate the stability of mine developments due to nearby mining activity. A case study comprising four consecutive mine levels in a deep underground metal mine in Sudbury, Ontario has been adopted for this study. The stability performance of the haulage drift is assessed using two separate evaluation criteria, namely Mohr-Coulomb yield function and Brittle Shear Failure. Random Monte-Carlo (RMC) technique is then employed in conjunction with Finite difference modelling software FLAC to determine the probability of instability or unsatisfactory performance of the haulage drift with respect to nearby mining sequence. In this study, the haulage drift performance is considered unsatisfactory when the yield zones or brittle shear failure around the haulage drift extend beyond the anchorage limit of the rock support. A comparison of the results from Mohr-Coulomb and Brittle Shear conditions has revealed that Mohr-Coulomb is more conservative from a design point of view. A three-dimensional, elastoplastic, finite difference model (FLAC 3D) is then constructed to simulate the case study mining orezone. The unsatisfactory performance of the intersection is evaluated with respect to mining sequence in terms of the strength-to-stress ratio computed by FLAC3D. Unsatisfactory stability performance is defined by a strength-to-stress ratio that is less than 1.4 and its corresponding extent into the rockmass around the intersection. Due to the large size of the FLAC3D model, the probabilistic simulations are conducted with the Point-Estimate Method (PEM), which requires significantly lesser number of simulations than Random Monte-Carlo (RMC). The results are presented and categorized with respect to probability, instability, and mining stage. In order to validate the numerical model, Multi-point borehole extensometers (MPBX) are installed at selected intersections to monitor the rock deformations as mining activities progress. The monitoring results revealed a lateral shift of the drift walls toward the orebody and much less deformations in the drift back. Finally, a methodology is developed to estimate the geotechnical risk of drift instability by considering the probability of failure and cost of consequence of such failure at an intersection. A 5-level risk index is derived which ranges from low to extreme. The methodology is demonstrated through an intersection from the case study mine, and the risk index is shown to vary with mining sequence. It is shown that the risk-index methodology can be used to confirm the need for enhanced supports, but it can also be used as basis for the comparison alternative mine designs.

Cryopreservation is a key technology in biology and clinical practice. This paper presents a digital microfluidic device that automates sample preparation for mammalian embryo vitrification. Individual micro droplets manipulated on the microfluidic device were used as micro-vessels to transport a single mouse embryo through a complete vitrification procedure. Advantages of this approach, compared to manual operation and channel-based microfluidic vitrification, include automated operation, cryoprotectant concentration gradient generation, and feasibility of loading and retrieval of embryos.

This paper proposes a new biometric identifier for humans based on eye blinking waveform extracted from brain waves. Brain waves were recorded using Neurosky Mindwave headset from 25 volunteers. Two approaches are adopted for the pre-processing stage; the first approach uses empirical mode decomposition to isolate electro-oculogram signal from brain waves, then, extracts eye blinking signal. The second approach extracts eye blinking signal directly from brain waves. Features are extracted based on time delineation of the eye blinking waveform and classified using linear discriminant analysis. The best correct identification and equal error rates achieved are 98.51% and 2.5% for identification and verification modes respectively. The obtained results in this paper confirm that eye blinking waveform carries discriminant information and is therefore appropriate as a basis for human recognition task.