The interactive force between fat, oil, and grease (FOG) deposits and the effect of food waste disposers on kitchen drainage systems.

Food waste disposers (FWDs) streamline kitchen waste management and facilitate waste classification, whether they would increase the potential of blockage in kitchen drainage system is still unknown. This study conducted a theoretical analysis of the interactive forces between fat, oil, and grease (FOG) deposits and their aggregation on pipe walls. The study involved grading food waste particles processed by FWDs using sieving and weighing techniques to determine the mean weight diameter (MWD) of various aggregations. A full-scale experimental system, implemented in a 60-m high test tower, simulated blockages in horizontal pipes of high-rise buildings. The effect of pipeline materials and particle sizes on blockage were examined by measuring the adhesion of deposits on horizontal pipes. Energy dispersive spectrometer (EDS) analysis suggested that liquid bridge force is a primary factor in aggregate formation. Hand-cut particles formed aggregates with the highest MWD value. Particle size analysis revealed that sizes ranging from 2.36 to 4.75 mm, 1.18-2.36 mm, and 0.60-1.18 mm constituted over 80 % of particles ground by FWDs, with an average size of 2.16 mm. Results of full-scale experiment indicate particle diameters, friction coefficients and lipophilic coefficient significantly affected the propensity of these aggregates to adhere to pipes. Notably, particles processed by FWDs tended to cause blockages more frequently than hand-cut particles. These findings elucidate the deposition mechanism of FOG deposits and offer strategies to reduce blockages in kitchen drainage systems, such as reducing current grinding particle size by 18 % to 1.77 mm or selecting pipes like cast iron and high-density polyethylene.

Physical and chemical characteristics of fat, oil and grease deposits in Chinese kitchen drainage systems.

The blockage of kitchen pipes seriously affects people's normal life. Minimal research is reported on fat, oil and grease (FOG) deposits in kitchen drainage pipes in China. In this study, 16 collected kitchen pipe deposits from various pipe materials are tested using physical and chemical methods. Experimental results show that samples have rough surfaces with porosity between 7 and 20% and appear as milky white lumps with moisture content less than 30% and the density is less than 1.000 g/cm3. Larger diameter of pipes can short blockage period. The oil content varies in deposits. The frequency of restaurants using oil is eight times higher than the family kitchen and the number of oil using is four times. The types of all free fatty acids in the samples are C14-C20, and the content of C16H32O2 is the highest. The highest metal content in the sample is calcium ion, up to 605.036 mg/L. Not only samples have a discontinuity formation process, but also characteristic absorption spectrum between 1300 and 1420, 1550 and 1610 and 1745 cm-1 also draws that saponification reaction occurs during the formation of these samples. The composition and formation rules of FOG deposits analysed can provide reference to prevent and remove blockages in the pipes and develop the kitchen drainage system in China.

Effect of Stacking Sequence on Fatigue Performance of CFRP-Al Single-Lap Adhesive Joints: Experimental Study.

This study aimed to explore failure mechanisms of carbon fibre-reinforced plastic (CFRP)-aluminium (Al) single-lap adhesive joints which CFRP adherends had different stacking sequences. These results showed that fatigue performance of CFRP decreased as the number of 45° plies increased, which caused the initial failure location to gradually move from the adhesive layer towards the CFRP. Under high load levels, joint-failure models were influenced by the stacking sequence of CFRP; large-area cohesive failure occurred in joints when the CFRP stacking sequence was [0/90]4s and [0/45/-45/90]2s, and delamination failure occurred when the CFRP stacking sequence was [45/-45]4s, due to the weak interlaminar properties of CFRP. However, under low load levels, the stacking sequence of CFRP had little effect on the failure model of the joint, with interfacial failure being the main failure mode for all joints due to weakening of the mechanical interlock.

Phantom limb pain: A literature review.

Since the phantom limb sensation was first described by the French military surgeon Ambroise Pare in the 16th century, the number of studies surrounding phantom limb pain has increased every year. Especially in recent decades, scientists have achieved a better understanding of the mechanism and treatment of phantom limb pain. Although many hypotheses have been agreed and many treatments have been proven effective, scientists still do not have a very systematic understanding of the phantom limbs. The purpose of this review article is to summarize recent researches focusing on phantom limb in order to discuss its definition, mechanisms, and treatments.