A statistical interestingness measures for XML based association rules

Recently mining frequent substructures from XML data has gained a considerable amount of interest. Different methods have been proposed and examined for mining frequent patterns from XML documents efficiently and effectively. While many frequent XML patterns generated are useful and interesting, it is common that a large portion of them is not considered as interesting or significant for the application at hand. In this paper, we present a systematic approach to ascertain whether the discovered XML patterns are significant and not just coincidental associations, and provide a precise statistical approach to support this framework. The proposed strategy combines data mining and statistical measurement techniques to discard the non significant patterns. In this paper we considered the "Prions" database that describes the protein instances stored for Human Prions Protein. The proposed unified framework is applied on this dataset to demonstrate its effectiveness in assessing interestingness of discovered XML patterns by statistical means.When the dataset is used for classification/prediction purposes, the proposed approach will discard non significant XML patterns, without the cost of a reduction in the accuracy of the pattern set as a whole

Modification of Capacitive Charge Storage of TiO2 with Nickel Doping

For practical deployment of supercapacitors characterized by high energy density, power density and long cycle life, they must be realized using low cost and environmentally benign materials. Titanium dioxide (TiO2) is largely abundant in the earth's crust; however, they show inferior supercapacitive electrochemical properties in most electrolytes for practical deployment. In this paper, we show that nickel doped TiO2 (Ni:TiO2) nanowires developed by electrospinning showed five times larger capacitance (∼200 F g−1) than the undoped analogue (∼40 F g−1). Electrochemical measurements show that the Ni:TiO2 nanowires have 100% coulombic efficiency. The electrodes showed no appreciable capacitance degradation for over 5000 cycles. The superior charge storage capability of the Ni:TiO2 could be due to its high electrical conductivity that resulted in five orders of magnitude higher ion diffusion as determined by cyclic voltammetry and electrochemical impedance spectroscopy measurements

Nanoarchitectonics of low process parameter synthesized porous carbon on enhanced performance with synergistic interaction of redox-active electrolyte for supercapacitor application

To develop materials of lower embodied energy and materials footprint for energy storage industry, the present work reports synthesis of porous carbon from a waste wetland weed (wild sugarcane) using low process parametric conditions (temperature and impregnation ratio) and their electrochemical capacitive (synonymously known as supercapacitors) charge storage performance in aqueous and redox active electrolytes. The phase, surface chemistry, physical surface, and morphology of the porous carbon thus developed are studied in detail using X-ray diffraction, gas adsorption measurements, Fourier-transform infrared spectroscopy, X-ray photoelectron spectroscopy, scanning and transmission electron microscopy techniques. Porous carbon synthesized at 500 °C, with the activator ZnCl2, resulted in a combination of micro and meso pores and a specific surface area ∼1294 m2 g−1. The optimized electrodes show outstanding energy storage performance, viz. specific capacitance of ∼414 F g−1 (three-electrode system) and ∼197 F g−1 (two-electrode system) at 1 A g−1 current density in aqueous 1 M H2SO4 electrolyte. The porous activated carbon showed high performance in terms of electrochemical stability of 96 % in half cell configuration for 10,000 cycles, while the symmetric device showed 80 % cyclic stability for 5000 cycles in full cell configuration. Addition of redox active 0.01 M hydroquinone in the 1 M H2SO4 significantly improved the storage capacity to 540 C g−1 at current density of 3 A g−1 in two-electrode configuration and maintained 72 % of capacity for 5000 cycles. The redox-active symmetric supercapacitors show an energy density ∼26.9 W h kg−1 and power density ∼5527 W kg−1 and other related electrochemical properties

Bambara groundnut: an exemplar underutilised legume for resilience under climate change

Main conclusion Bambara groundnut has the potential to be used to contribute more the climate change ready agriculture. The requirement for nitrogen fixing, stress tolerant legumes is clear, particularly in low input agriculture. However, ensuring that existing negative traits are tackled and demand is stimulated through the development of markets and products still represents a challenge to making greater use of this legume. Abstract World agriculture is currently based on very limited numbers of crops, representing a significant risk to food supplies, particularly in the face of climate change which is expected to increase the frequency of extreme events. Minor and underutilised crops can help to develop a more resilient and nutritionally dense future agriculture. Bambara groundnut [Vigna subterranea (L.) Verdc.[, as a drought resistant, nitrogen-fixing, legume has a role to play. However, as with most underutilised crops, there are significant gaps in knowledge and also negative traits such as 'hard-to-cook' and 'photoperiod sensitivity to pod filling' associated with the crop which future breeding programmes and processing methods need to tackle, to allow it to make a significant contribution to the well-being of future generations. The current review assesses these factors and also considers what are the next steps towards realising the potential of this crop

A structure-function analysis of the left ventricle

This study presents a structure-function analysis of the mammalian left ventricle and examines the performance of the cardiac capillary network, mitochondria, and myofibrils at rest and during simulated heavy exercise. Left ventricular external mechanical work rate was calculated from cardiac output and systemic mean arterial blood pressure in resting sheep (Ovis aries; n = 4) and goats (Capra hircus; n = 4) under mild sedation, followed by perfusion-fixation of the left ventricle and quantification of the cardiac capillary-tissue geometry and cardiomyocyte ultrastructure. The investigation was then extended to heavy exercise by increasing cardiac work according to published hemodynamics of sheep and goats performing sustained treadmill exercise. Left ventricular work rate averaged 0.017 W/cm3 of tissue at rest and was estimated to increase to ∼0.060 W/cm3 during heavy exercise. According to an oxygen transport model we applied to the left ventricular tissue, we predicted that oxygen consumption increases from 195 nmol O2·s-1·cm-3 of tissue at rest to ∼600 nmol O2·s-1·cm-3 during heavy exercise, which is within 90% of the oxygen demand rate and consistent with work remaining predominantly aerobic. Mitochondria represent 21-22% of cardiomyocyte volume and consume oxygen at a rate of 1,150 nmol O2·s-1·cm-3 of mitochondria at rest and ∼3,600 nmol O2·s-1·cm-3 during heavy exercise, which is within 80% of maximum in vitro rates and consistent with mitochondria operating near their functional limits. Myofibrils represent 65-66% of cardiomyocyte volume, and according to a Laplacian model of the left ventricular chamber, generate peak fiber tensions in the range of 50 to 70 kPa at rest and during heavy exercise, which is less than maximum tension of isolated cardiac tissue (120-140 kPa) and is explained by an apparent reserve capacity for tension development built into the left ventricle.This research was supported by an Australian Research Council Discovery Project Award to R. S. Seymour, S. K. Maloney, and A. P. Farrell (DP-120102081). E. P. Snelling holds a South African Claude Leon Foundation Postdoctoral Fellowship. J. E. F. Green is supported by an Australian Research Council Discovery Early Career Researcher Award (DE- 130100031). A. P. Farrell holds a Canada Research Chair and is supported by a Discovery Grant from the Natural Sciences and Engineering Research Council of Canada.http://jap.physiology.org2017-10-31hb2017Paraclinical Science

An experimental investigation of magnetorheological (MR) fluids under quasi-static loadings

In our earlier work, test equipment has been designed, simulated and fabricated to perform experiment on MR fluids in squeeze mode. Preliminary results were gathered and presented for the purpose of validating the test equipment. Therefore, in this paper, a further systematic investigation of MR fluids in squeeze mode has been carried out. As a result, MR fluids experienced rheological changes in three stages during compression and tension. Fluid-particles separation phenomenon was the main caused for the unique behaviour of MR fluids. Particle chains depended on the structure transformation in which the carrier fluid movement can be controlled by changing the magnetic field strength

Thermal Conductivity Enhancement and Sedimentation Reduction of Magnetorheological Fluids with Nano-Sized Cu and Al Additives

This work presents enhanced material characteristics of smart magnetorheological (MR) fluids by utilizing nano-sized metal particles. Especially, enhancement of thermal conductivity and reduction of sedimentation rate of MR fluids those are crucial properties for applications of MR fluids are focussed. In order to achieve this goal, a series of MR fluid samples are prepared using carbonyl iron particles (CIP) and hydraulic oil, and adding nano-sized particles of copper (Cu), aluminium (Al), and fumed silica (SiO 2 ). Subsequently, the thermal conductivity is measured by the thermal property analyser and the sedimentation of MR fluids is measured using glass tubes without any excitation for a long time. The measured thermal conductivity is then compared with theoretical models such as Maxwell model at various CIP concentrations. In addition, in order to show the effectiveness of MR fluids synthesized in this work, the thermal conductivity of MRF-132DG which is commercially available is measured and compared with those of the prepared samples. It is observed that the thermal conductivity of the samples is much better than MRF-132DG showing the 148 increment with 40 vol of the magnetic particles. It is also observed that the sedimentation rate of the prepared MR fluid samples is less than that of MRF-132DG showing 9 reduction with 40 vol of the magnetic particles. The mixture optimized sample with high conductivity and low sedimentation was also obtained. The magnetization of the sample recorded an enhancement of 70.5 when compared to MRF-132DG. Furthermore, the shear yield stress of the sample were also increased with and without the influence of magnetic field

Thermally-Induced Crack Evaluation in H13 Tool Steel

This study reported the effect of thermal wear on cylindrical tool steel (AISI H13) under aluminum die-casting conditions. The AISIH13 steels were immersed in the molten aluminum alloy at 700 �C before water-quenching at room temperature. The process involved an alternating heating and cooling of each sample for a period of 24 s. The design of the immersion test apparatus stylistically simulated aluminum alloy dies casting conditions. The testing phase was performed at 1850, 3000, and 5000 cycles. The samples were subjected to visual inspection after each phase of testing, before being examined for metallographic studies, surface crack measurement, and hardness characteristics. Furthermore, the samples were segmented and examined under optical and Scanning Electron Microscopy (SEM). The areas around the crack zones were additionally examined under Energy Dispersive X-ray Spectroscopy (EDXS). The crack’s maximum length and Vickers hardness profiles were obtained; and from the metallographic study, an increase in the number of cycles during the testing phase resulted in an increase in the surface crack formation; suggesting an increase in the thermal stress at higher cycle numbers. The crack length of Region I (spherically shaped) was about 47 to 127 �m, with a high oxygen content that was analyzed within 140 �m from the surface of the sample. At 700 �C, there is a formation of aluminum oxides, which was in contact with the surface of the H13 sample. These stresses propagate the thermal wear crack length into the tool material of spherically shaped Region I and cylindrically shape Region II, while hardness parameters presented a different observation. The crack length of Region I was about 32% higher than the crack length of Region II

Effect of tungsten carbide partial dissolution on the microstructure evolution of a laser clad surface

Laser surface modification has been a way to promote wear resistance in dies and molds application. Previously, researchers have succeeded in enhancing surface properties through laser surface modification. The addition of particles in laser cladding process enhanced the surface properties by strengthening the modified AISI H13 tool steel structure. Controlled parameter was laser power, pulse repetition frequency (PRF) and scanning speed with a range of 1.7–2.5 kW, 30–70 Hz and 10.5–24.5 mm s−1 respectively. The powder addition executed by a preplaced method. The grain size and hardness properties of treated samples were characterized using scanning electron microscope (SEM) and hardness Vickers indenter respectively. Surface roughness was characterized using roughness tester. From the findings, tungsten carbide (WC) particles were dissolved homogenously within refined substrate grain structure at higher laser energy. Higher laser scanning speed contributed in uniform particles distribution. The grain refinement with W element in modified layer resulted in maximum hardness of 660 HV. Rapid solidification during laser processing produced metastable phase formation grain refinement, and a higher fraction of grain boundary which resulted in grain boundary strengthening, grain refinement and metastable phase formation. In this paper laser cladding of AISI H13 tool steel with micron size WC particles addition for enhanced surface properties was investigated. These findings are important to design high precision modification of die surface for high temperature forming process

Design of laser melting of tool steel for surface integrity enhancement

In this study, laser surface modification hasbeen conducted on AISI H13 tool steel for enhance surface properties. A maximum 300 W high power Nd:YAG laser system with pulse mode was used to modify both materials sample surface. Laser processing was conducted using a 33full factorial design. Three controlled parameters were laser peak power, pulse repetitive frequency (PRF)and scanning speed. The modified surface was characterized for metallographic study, surface morphology and hardness properties. The results showedthat finer grain formation occurred at laser modified layer. Grain size decreased along the cross-section of the melted pool, which consequently increased the hardness due to grain refinement. The overlapincreased significantly with decreasing laser scanning speed which affected samplesurface integrity. Low surface roughness obtained at the highest scanningspeed, low peak power and PRF. Process optimization was carried out for maximum surface hardness and laser modified depth, and minimum surface roughness. These findings indicate potential application of tool steel for thermal wearresistant applications through laser surface modification