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In recent years, there is an ever-growing demand for providing sustainable power to flexible electronics, the Internet of Things, cloud computing and artificial intelligence. The additive manufacturing process can be used to develop energy harvesting devices with a variety of essential properties to fulfil this requirement. In the present work, flexible and transparent Triboelectric nanogenerator devices for energy harvesting applications are fabricated using Ionic liquid processed polyvinylidene fluoride and polyamide 6 by a material extrusion process. To improve the formation of the electroactive β- phase, PVDF was processed with varying ionic liquid content (5 %, 10 %, 15 %, 20 %), with studies conducted on its impact on dielectric properties and energy output of TENG devices. The triboelectric performance studies show that PVDF processed with 15 % of Ionic liquid provides the maximum peak output voltage of 180.5 V, short-circuit current of 16.5 µA and power density of 3.42 Wm−2. The addition of an Ionic Liquid to PVDF enhances the polar β-phase, dielectric constant, modify surface potential, and serves as a conductive medium for electrons trapped from the surface to the bulk material, leading to enhanced triboelectric charge density and improved performance of TENG devices. Similarly, the additive manufacturing method enables more rough surface contact between the two tribolayer through increased surface roughness and uniform layer printing, which leads to an increase in the charge transfer thereby boosting energy output performance. This study shows the feasibility of fabricating flexible TENG devices using Ionic liquid processed PVDF through additive manufacturing, with potential applications in energy harvesting. [Display omitted] • The TENG devices fabricated via additive manufacturing, using ionic liquid processed PVDF and Polyamide 6. • Ionic liquid which contains cation E mim + and anion Cl-, interacts with CF 2 and CH 2 dipoles, promoting β-phase formation in PVDF. • TENG produces a maximum output voltage of 180.5 V, short-circuit current of 16.5 µA, and a power density of 3.42 Wm−2. • The ionic liquid serves as a conductive medium for electron trapping. • 3D printing improves surface roughness, boosts charge transfer, and enhances TENG device power output. [ABSTRACT FROM AUTHOR]

Zirconium diboride is a potential ceramic for high temperature applications because of its combination of properties, such as very high melting point, high hardness, elevated temperature strength, good thermal and electrical conductivity. Although the near net shape components are made from this material, machining is required to create additional features for the application requirements. This ceramic's high hardness and low fracture toughness make it very difficult to use the conventional processes for machining. The good electrical conductivity of this ceramic makes electrical discharge machining (EDM) the preferred machining process. This paper presents the surface and sub-surface modifications during Wire cut EDM (WEDM) and EDM of ZrB 2 an ultra high temperature ceramic (UHTC) and ZrB 2 -GNP (ceramic matrix composite with 7 vol% Graphene Nano Platelets) along with the surface characterization of the copper electrode (EDM tool). Scanning Electron Microscope (SEM) with Energy Dispersive Spectroscopy (EDS) and Raman spectroscopy (for GNPs) were used to characterize the melt-solidified layer and the recrystallized region. The presence of micro cracks and pores was observed in the melt-solidified layer. Growing dendrites of ZrB 2 were observed in the high magnification SEM images of the melt-solidified layer surface. Under the melt-solidified layer, a recrystallized fine grain structure was observed with reduced porosity compared to the rest of the bulk. After the WEDM of ZrB 2 -GNP (7 vol%), the stacks of cut GNP were retained, whereas GNPs were damaged after EDM The end surface of the copper electrode showed the partial deposition of ZrB 2 and the formation of a micro scale pattern on it. The effect of peak current and pulse ON time on surface roughness (S a), material removal rate (MRR) and relative tool wear (%) were studied for ZrB 2 -GNP (7 vol%) The results indicated that the surface roughness (S a), MRR and the relative tool wear (%) increase with increasing peak current. The rise in pulse ON time also increases surface roughness (S a) and MRR but reduces the relative tool wear rate (%) [Display omitted] • Patches of melt solidified layer with microcracks and open pores on the surface. • Growing dendrites on surface of melt solidified layer due to rapid solidification. • Recrystallized grains in sub surfaces with reduced porosity and grain size. • Cutting of GNPs in slicing action by the brass wire in WEDM. • GNPs damaged due to the continuous advancement of sparking tool electrode in EDM. [ABSTRACT FROM AUTHOR]

Reliable and dynamic composition of web services is considered as essential for ensuring continuous services to the users since they are responsible for integrating varsity of applications in spite of their independency. The significant development in web services domain in the last two decades enable the option of devising novel service composition and service selection schemes for optimal performance and success rate of dynamic web service composition. Majority of the research works proposed for dynamic composition of web services was confirmed to be formulated using the characteristics of Quality of Service (QoS) or Transactional features of workflow. Improved Cosine Similarity-based Artificial Bee Colony Optimization Scheme for Web Service Composition (ICS-ABCO-WSC) is proposed for integrating the characteristics of QoS and transactional features for determining optimal candidate service solution from the workflow modeled graph generated during reactive service composition. ICS-ABCO-WSC is proved to enhance the rate of exploitation and exploration by incorporating opposition learning in employee bee phase and, combinatorial search strategical equations and enhance rate factor in the employee and onlooker bee phase respectively. The success rate and optimality index derived using experimental investigation of ICS-ABCO scheme is proved to be 26% and 32% excellent to compared baseline graph-modeled web service composition techniques. This improvement is realized in ICS-ABCO-WSC due to its potential of enhancing the precision and acceleration rate of converging solution achieved in Artificial Bee Colony Optimization technique. [ABSTRACT FROM AUTHOR]

Background: A cluster of seven cases of skin and wound infections caused by a multiply resistant meticillin-resistant Staphylococcus aureus (MRSA) were detected in a small-town community in South Yorkshire. Initial microbiological investigations showed that all isolates belonged to a spa type observed rarely in England (t1476).Aim: To describe the epidemiology of t1476 MRSA in South Yorkshire.Methods: Retrospective and prospective case ascertainment was promoted through communication with local microbiology laboratories. Public health investigation included a detailed review of clinical notes for a subset of nine cases. Genomic and phylogenetic analysis was undertaken on t1476 MRSA.Findings: Thirty-two cases of t1476 MRSA infection or colonization were identified between December 2014 and February 2018. Cases were older adults (aged 50-98 years). Healthcare exposures for a subset of nine cases indicated frequent contact with a team of district nurses, with all but one case receiving treatment on the same day as another case prior to their own diagnosis. No cases were admitted to hospital at the time of specimen collection. Despite detailed investigations, no carriers were detected among district nursing staff. A long-term carrier/super-shedder was not found. Phylogenetic analysis indicated that t1476 MRSA cases from South Yorkshire were monophyletic and distant from both MRSA of the same lineage from elsewhere in the UK (N = 15) and from publicly available sequences from Tanzania.Conclusion: Genomic and epidemiological analyses indicate community-based transmission of a multiply resistant MRSA clone within South Yorkshire introduced around 2012-2013, prior to the detection of a spatial-temporal cluster associated with a distinct risk group. Surveillance data indicate continued circulation. [ABSTRACT FROM AUTHOR]

This paper investigates the sliding friction and erosion resistance of untreated and heat-treated electroless Ni–B coatings, reinforced with ZrO 2 and (3 mol%) YSZ nanoparticles. A ball-on-flat system was used for the sliding friction wear test, and an air jet carries solid particles for the erosion wear test. The wear scars were studied with a 3D profilometer. Further, a scanning electron microscope (SEM) for morphological and energy-dispersive spectroscopy (EDS) was used to examine the chemical properties of the worn surfaces. These scars correlate with properties of hardness, Young's modulus, and fracture toughness has been studied with microhardness and nanoindentation tests. X-ray diffraction (XRD) analyzed the coating phase structure and synthesis. The wear tests revealed that Ni–B–ZrO 2 and Ni–B-YSZ coatings had lower friction coefficients at heat-treated conditions (with an average value of μ = 0.3) than Ni–B, HT, which had a 14 % higher coefficient. Consequently, the Ni–B-YSZ demonstrates the lowest specific wear rates (2.4 x10−6 mm3/N-m) and erosion resistance which is more promising for use in indented gun barrel applications. [ABSTRACT FROM AUTHOR]

Pre-sintered zirconia is preferred as a restoration material in dental applications due to its excellent strength and fracture toughness. When abrasive processes were used to obtain the required shape of (Y-TZP) yttria-stabilized tetragonal pre-sintered zirconia, it resulted in material strength degradation in the presence of coolant. Therefore, experiments were carried out on pre-sintered zirconia with diamond grinding wheel to evaluate the performance of cooling conditions such as dry, wet and minimum quantity lubrication (MQL). The effects of different environments on the grinding performance were studied based on the temperature distribution, phase transformation, flexural strength, microhardness and edge chipping damage. The Raman spectroscopy and X-ray diffraction analysis were used to estimate the quantity of monoclinic phase in pre-sintered zirconia. The temperature rise of the workpiece material during the grinding experiment was not higher and insufficient to cause the thermal stresses. The microstructural changes induced by grinding under different cooling strategies were associated with the quantitative assessment of monoclinic phase. The flexural strength of ground components was improved in the dry condition compared to the other process due to the absence of the defective layer and the occurrence of Y 3+ ions segregation. After grinding, there was a slight decrease in the hardness value by (1–8 HV), which was due to the formation of microcracks in the subsurface layer of the ground surface. In addition, to ensure the presence of microcracks, the edge chipping depth was measured. The damage depth obtained from the wet condition showed a higher value of 30 µm compared to the dry and MQL conditions. [ABSTRACT FROM AUTHOR]

After stress corrosion crack testing in a MgCl 2 environment, turned surface of super duplex stainless steel showed four types of cracks. The residual stress and surface defects such as feed marks and long grooves generated after machining played a significant role in the direction and orientation of these cracks. The generated cluster of cracks acted as a precursor to the formation of pits. The biaxial tensile stress in the surface promoted successive branching of cracks, which led to high crack density. The subsurface results showed that cracks passing perpendicular to feed marks found more detrimental than the other types. [ABSTRACT FROM AUTHOR]

An outbreak of listeriosis in England affecting 14 people between 2010 and 2012 and linked to the consumption of pork pies was investigated. All 14 individuals were older than 55 years, 12 were men, and 10 reported the presence of an underlying condition. All were resident in or had visited either of two English regions and were infected with the same strain of Listeria monocytogenes. In interviews with 12 patients, 9 reported eating pork pies, and individuals that consumed pork pies were significantly more likely to be infected with an outbreak strain than were individuals with sporadic cases of listeriosis infections in England from 2010 to 2012. Pork pies were purchased from seven retailers in South Yorkshire or the East Midlands, and the outbreak strain was recovered from pork pies supplied by only the producer in South Yorkshire. The outbreak strain was also recovered from samples of finished product and from environmental samples collected from the manufacturer. The likely source of contamination was environmental sites within the manufacturing environment, and the contamination was associated with the process of adding gelatin to the pies after cooking. Inadequate temperature control and poor hygienic practices at one of the retailers were also identified as possible contributory factors allowing growth of the pathogen. Following improvements in manufacturing practices and implementation of additional control measures at the retailers' premises, L. monocytogenes was not recovered from subsequent food and environmental samples, and the outbreak strain was not detected in further individuals with listeriosis in England. [ABSTRACT FROM AUTHOR]

• The crack growth rate didn't reach a saturation stage after 5 h immersion time. • More time of exposure contributed to different forms of localised corrosion. • Formation SCC and localised corrosion affected the surface roughness of component. • Pit/crack transition findings showed that the pits fuse together to form a crack of high intensity. The poor machining characteristics of super duplex stainless steels (SDSS) affect the surface integrity as it induces tensile residual stress in the parts. When this machined part is exposed to hostile chloride conditions, it results in the stress corrosion crack (SCC) formation, thereby impacting their service life. To understand the cracking phenomenon involved, it is important to study the distinct characteristics of cracks formed in compliance with the machining (turning) process. This study focusses on studying the effects of machined surface integrity on the stress corrosion cracking of SDSS. Following machining, the specimens were subjected to SCC examination in the chloride condition at different immersion time of 1 h, 2 h, and 5 h. The testing was done in pursuant with ASTM G36 standard. The result indicated that major cracks generated along both parallel as well as the perpendicular direction of machining marks due to the high magnitude of biaxial tensile residual stress. With the increase in immersion time (5 h), new forms of crack and localized corrosion were noticed on the surface. At 1 h and 2 h, only the major cracks were evident, along with minor pit formation on the surface. But at 5 h, selective attack/selective leaching occurred on the turned surface along with the formation of network of cracks. Analysis of the transition pit/crack behaviour of revealed that different pits merge to form a detrimental crack with more intensity than the major cracks. The crack density continue to grow with immersion time of 5 h and also there is no evidence was observed on reduction of crack density. However, the quantification of crack density was not possible at 5 h due to the complex network of high density crack formation. The microstructure analysis revealed that the ferrite phase was more vulnerable to SCC than the austenite phase in chloride environment. [ABSTRACT FROM AUTHOR]

[Display omitted] • This study evaluates the geometric accuracy of 3D-printed hole in Ti-6Al-4 V plate suitable for bioimplants and also focuses on the hole diameter precision and surface roughness. • As specimen 8 having the parameter of laser power 195 W, the scanning speed 900 mm/sec and the hatch distance 70 µm exhibited minimal average geometric errors across top surface roughness, internal hole curve surface roughness, external and internal circular hole shapes. • These results are very important for designing processes to ensure high-quality 3D-printed titanium alloy specimens. This study examines the quality of circular-hole 3D-printed objects using laser powder bed fusion (L-PBF) on Ti-6Al-4V titanium alloy that typically used for orthopedic implants. Meanwhile measuring surface roughness and hole dimension deviations in AM specimens is very challenging. Thus, the specimens were printed with varying process parameters, followed by an L9 orthogonal array experiment, where parameters included laser power (LP) at 175, 185, and 195 W; scanning speed (SS) at 600, 900, and 1200 mm/s; and hatch distance (HD) at 70, 90, and 110 µm. Thus the, minimum surface roughness values are Ra 2.4 µm for the top surface and Ra 16.06 µm for the inside hole curve. Whereas the smallest hole deviations are 0.1102 mm for external and 0.2094 mm for internal diameters. Therefore, this analysis include FESEM, EDX, XRD, profilometry and stereomicroscopy. Where the best settings are LP 195 W, SS 900 mm/s, and HD 70 µm, producing well-fused, uniform α-phase Ti-6Al-4V specimens that are suitable for biomedical applications. [ABSTRACT FROM AUTHOR]

• A method based on image processing is proposed to identify the regular deterministic laser texture pattern. • A detailed image processing steps followed to identify the texture pattern. • A proposed radial length function is used to identify the pattern using correlation measures. • The ISO concept of circularity definition extended to triangle, elliptical, square patterns. • The error of the measurement is calculated using the proposed method. Texturing of surfaces is often done to improve the surface properties. The purpose of this study is to develop a methodology for two dimensional inspection of the quality of textured surfaces automatically using machine vision techniques. The quality is measured in an absolute sense, using the value of offset between ideal shapes that inscribe and circumscribe the boundary of a machined feature. This gives an idea about machining accuracy rather than similarity between the machined texture shape and intended ideal shape which most of the existing methods try to measure. The techniques developed are tested on textures created on polished titanium surface using laser micro machining technique. In this study the textured surfaces made up of four different shapes namely circle, ellipse, triangle and square are considered. The automatic classification of texture shapes into the mentioned categories is achieved by finding their correlation with ideal shapes. For the purpose of measuring the machining accuracy, this paper extends the ISO definition of circularity error to ellipse, triangle and square shapes and proposes a method to fit least square triangle and square shapes to a given two dimensional point clouds. The error and the average dimension of the features are calculated from circumscribing, inscribing and least square fit shapes. The results generated by the proposed algorithms are found to be in good agreement with the known dimension values set during machining of the samples and manual measurements done using a stereo-microscope images. This indicate the suitability of this procedure for characterization of textured surfaces for different applications. [ABSTRACT FROM AUTHOR]

Transient stress relaxation test can be used to estimate activation volume for plastic deformation. The analysis is complicated due to the non-constancy of mobile dislocation density during relaxation. The reloading yielding post stress relaxation has a direct correlation with the change in mobile dislocation density during relaxation. However, this feature is ignored in the past studies. In the present work, the reloading yielding phenomenon in dual phase (α + β) titanium alloy (Ti–6Al–4V) is investigated using phenomenological stress relaxation model. Based on indirect experimental evidences, it is shown that the reloading yielding is due to regeneration of new dislocations and not due to unpinning of sessile dislocations, as assumed previously. The improvement of ductility due to stress relaxation follows a similar trend reported in literature. The ductility improvement is analyzed using both microstructure changes and thermal gradient. Fractographs of failed samples were investigated to understand the fracture characteristics and quantitative analyses were performed using image processing to correlate the microstructure mechanisms responsible for enhanced ductility. Thermal history at select locations were recorded using thermocouple and were used to analyze the contribution of thermal gradient in ductility. The necessity of a comprehensive approach to model ductility improvement in non-monotonic stress relaxation test is explored. • Reloading yielding post relaxation increases and then decreases with relaxation time. • Reloading yielding is due to the combined effect of regeneration of dislocations and unpinning. • Unpinning will reduce the reloading yielding, which is contrary to the earlier reports. • Good correlation of experimental data with prediction from phenomenological stress relaxation model. [ABSTRACT FROM AUTHOR]