Evaluation of multiple sewage-associated Bacteroides PCR markers for sewage pollution tracking

The host specificity of the five published sewage-associated Bacteroides markers (i.e., HF183, BacHum, HuBac, BacH and Human-Bac) was evaluated in Southeast Queensland, Australia by testing fecal DNA samples (n = 186) from 11 animal species including human fecal samples collected via influent to a sewage treatment plant (STP). All human fecal samples (n = 50) were positive for all five markers indicating 100% sensitivity of these markers. The overall specificity of the HF183 markers to differentiate between humans and animals was 99%. The specificities of the BacHum and BacH markers were > 94%, suggesting that these markers are suitable for the detection of sewage pollution in environmental waters in Australia. The HuBac (i.e., 63%) and Human-Bac (i.e., 79% specificity) markers performed poorly in distinguishing between the sources of human and animal fecal samples. It is recommended that the specificity of the sewage-associated markers must be rigorously tested prior to its application to identify the sources of fecal pollution in environmental waters.     

Comparison of the efficacy of an existing versus a locally developed metabolic fingerprint database to identify non-point sources of faecal contamination in a coastal lake

A comparison of the efficacy of an existing large metabolic fingerprint database of enterococci and Escherichia coli with a locally developed database was undertaken to identify the sources of faecal contamination in a coastal lake, in southeast Qld., Australia. The local database comprised of 776 enterococci and 780 E. coli isolates from six host groups. In all, 189 enterococci and 245 E. coli biochemical phenotypes (BPTs) were found, of which 118 and 137 BPTs were unique (UQ) to host groups. The existing database comprised of 295 enterococci UQ-BPTs and 273 E. coli UQ-BPTs from 10 host groups. The representativeness and the stability of the existing database were assessed by comparing with isolates that were external to the database. In all, 197 enterococci BPTs and 179 E. coli BPTs were found in water samples. The existing database was able to identify 62.4% of enterococci BPTs and 64.8% of E. coli BPTs as human and animal sources. The results indicated that a representative database developed from a catchment can be used to predict the sources of faecal contamination in another catchment with similar landuse features within the same geographical area. However, the representativeness and the stability of the database should be evaluated prior to its application in such investigation.     

Experimental studies on performance of reinforced concrete beam strengthened with CFRP under cyclic loading using FBG array

Investigations are increasingly being carried out in the area of utilizing Fiber Reinforced Plastic (FRP) materials for retrofitting and repairing existing damaged concrete structures due to their excellent properties. Favorable mechanical and material characteristics of FRP composites make them attractive for strengthening applications, whereas relatively higher material costs, insufficient knowledge in mechanics of their behavior, long-term durability and lack of related design codes are the issues that need to be addressed for mainstream application of these materials. Although there has been growing interest and field applications of strengthening concrete structures using Carbon Fiber Reinforced Plastic (CFRP) sheet/plate, very little information exists regarding the flexural fatigue behavior of reinforced concrete beams strengthened with CFRP. A common cause of failure in such strengthened members is associated with the debonding of CFRP substrate from the concrete in an abrupt manner. In order to understand the mechanism of debonding in strengthened concrete structures, embedment of strain sensors (Fiber Bragg Grating (FBG) array) between the concrete and CFRP is proposed in this paper. Due to the compatibility with CFRP material and being small in size, fiber optic sensor is a good choice for embedding at the interface to measure interfacial strain. This paper presents the experimental studies carried out on CFRP strengthened concrete members subjected to cyclic loading. A special emphasis has been placed on understanding the failure pattern using the embedded FBG sensors. Based on the studies it is concluded that the strain at the interface of CFRP strengthened concrete members can be measured.     

Exploiting the orbital motion of water particles for energy extraction from waves

In wave motion, the water particles are known to follow orbital paths. This orbital motion was used to drive five-bladed Savonius rotors. Experiments were performed on an array of four rotors placed in a two-dimensional (2-D) wave channel. The flow around the rotors was documented using particle image velocimetry measurements. The submergence of the rotors and the distance between them were varied, and the rotational speeds of the rotors (N_n) were recorded at different wave frequencies. It was found that rotational speeds increased with an increase in the wave frequency, as it amplified the wave height that increased the kinetic energy of the particles in their orbital motion. The rotational speeds decreased when the distance between the rotors increased. High rotational speeds are recorded when the array of the rotors is placed close to the water surface at the smallest centre-to-centre distance between the rotors.     

Static and low order anti-windup synthesis for cascade control systems with actuator saturation: An application to temperature-based process control

In this paper, a new framework for designing static and low order anti-windup compensator (AWC) for industrial cascade control systems with actuator saturation constraint is presented. Based on less conservative block diagonal quadratic Lyapunov function, sector boundedness, decoupled architecture, norm reduction and cascade loop compensation, linear matrix inequalities are developed which guarantee stability and suitable performance for overall closed-loop system. Static AWC parameters are obtained by comparing the full order AWC architecture with generalized architecture for cascade control system. Low order AWC is designed by sub-optimal approach in which AWC weights are tuned by designer. Anti-windup compensator is divided into inner and outer loop compensators which compensate the effect of saturation at each level. It is observed that the proposed methodology is less conservative than the traditional AWC schemes when applied to cascade control systems. The proposed scheme is successfully tested experimentally on a temperature-based process control system and results are outlined.     

Enhancing the Tribological Behavior of Lubricating Oil by Adding TiO2, Graphene,and TiO2/Graphene Nanoparticles

This article investigates the tribological behavior of nanoparticles (NPs) of titanium dioxide anatase TiO₂ (A), graphene, and TiO₂ (A) + graphene added to the pure base oil group ΙΙ (PBO-GΙΙ). The morphology of these two nanostructures of TiO₂ (A) and graphene was characterized by transmission electron microscopy (TEM). Oleic acid (OA) was blended as a surfactant into the formulation to help stabilize the NPs in the lubricant oil. A four-ball test rig was used to determine the tribological performance of six different samples, and an image acquisition system was used to examine and measure the wear scar diameter of the stationary balls. Field emission–scanning electron microscopy (FE-SEM) was used to examine the wear morphology. Energy-dispersive X-ray spectroscopy (EDX), element mapping, and Raman spectroscopy were employed to confirm the presence of (TiO₂ (A) + graphene) and the formation of a tribolayer/film on the mating surfaces. Moreover, a 3D optical surface texture analyzer was utilized to investigate the scar topography and tribological performance. The experiments proved that adding (0.4?wt% TiO₂ (A) + 0.2?wt% graphene) to the PBO-GΙΙ optimized its tribological behavior. These excellent results can be attributed to the dual additive effect and the formation of a tribofilm of NPs during sliding motion. Furthermore, the average reductions in the coefficient of friction (COF), wear scar diameter (WSD), and specific wear rate (SWR) were 38.83, 36.78, and 15.78%, respectively, for (0.4?wt% TiO₂ (A) + 0.2?wt% graphene) nanolubricant compared to plain PBO-GΙΙ lubricant.     

Plasmodium species aware based quantification of malaria parasitemia in light microscopy thin blood smear

Malaria is a serious worldwide disease, caused by a bite of a female Anopheles mosquito. The parasite transferred into complex life round in which it is grown and reproduces into the human body. The detection and recognition of Plasmodium species are possible and efficient through a process called staining (Giemsa). The staining process slightly colorizes the red blood cells (RBCs) but highlights Plasmodium parasites, white blood cells and artifacts. Giemsa stains nuclei, chromatin in blue tone and RBCs in pink color. It has been reported in numerous studies that manual microscopy is not a trustworthy screening technique when performed by nonexperts. Malaria parasites host in RBCs when it enters the bloodstream. This paper presents segmentation of Plasmodium parasite from the thin blood smear points on region growing and dynamic convolution based filtering algorithm. After segmentation, malaria parasite classified into four Plasmodium species: Plasmodium falciparum, Plasmodium ovale, Plasmodium vivax, and Plasmodium malaria. The random forest and K‐nearest neighbor are used for classification base on local binary pattern and hue saturation value features. The sensitivity for malaria parasitemia (MP) is 96.75% on training and testing of the proposed approach while specificity is 94.59%. Beside these, the comparisons of the two features are added to the proposed work for classification having sensitivity is 83.60% while having specificity is 94.90% through random forest classifier based on local binary pattern feature.     

Inconel 617 alloy creep life augmentation by graphene transfer coating

Journal of Mechanical Science and Technology - Presently, countries are trying to increase their energy efficiency. Therefore, the operating temperatures of very high temperature reactor (VHTR) and...     

Laser beam machining of zirconia ceramic: An investigation of micro-machining geometry and surface roughness

Journal of Mechanical Science and Technology - Micro-machining of dental ceramics namely as zirconium oxide is carried out through laser beam machining. Micro-channels of different sizes are...     

Slurry Erosion–Corrosion of Carburized AISI 5117 Steel

The erosion–corrosion of carburized and untreated low alloy steel (AISI 5117) has been investigated using slurry whirling-arm test rig. Erosion–corrosion tests were carried out in slurries composed of sand particles and either tap water or 3 % NaCl solution. The tests were carried out with particles concentration of 1 wt% and slurry stream impact velocity of 15 m/s. Silica sand having a nominal size range of 250–355 μm was used as an erodent. It has been shown that the erosion and erosion–corrosion resistance of AISI 5117 low alloy steel can be effectively improved by carburizing for all impact angles. However, the effectiveness of carburizing was the highest for an impact angle of 45°, where the erosion and erosion–corrosion resistance were increased by 60–40 %, respectively, compared with that of the untreated material. The results showed that the treated and untreated specimens behaved as ductile materials under erosion and erosion–corrosion tests, and the maximum mass loss occurred at an impact angle of 45°. SEM analysis showed that the erosion tracks developed on the untreated specimens were wider and deeper than that formed on the carburized specimens for erosion and erosion–corrosion tests.