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Spar Wingskin Joint (SWJ) comprises of a thin spar which overlaps and is co-cured to a thick wingskin by suitable adhesive materials. These joints are mostly used in integral modular fabrication of aircraft and fuselage wing structures usually made with curved laminated Fibre Reinforced Polymeric (FRP) composite panels. This paper deals with the analyses of initiation of adhesion failure and its propagation in SWJs subjected to transverse loadings using Finite Element Analyses (FEA) and fracture mechanics approach. Normal and shear stress distributions at different interfacial locations between the adherends and the adhesive have been evaluated. Tsai-Wu coupled stress failure criteria have been used to identify the location of onset of adhesion failure. The critical location for onset of adhesion failure has been found to be at the toe-end of the spar wingskin overlap region. Pre-embedded adhesion failure has been simulated at this location and Strain Energy Release Rate (SERR) components corresponding to Mode I, Mode II and Mode III of adhesion failure have been determined using the principle of Virtual Crack Closure Technique (VCCT). Rate of propagation of adhesion failure has been evaluated by sequential release of Multi-Point Constraint (MPC) and contact finite elements provided at the pre-embedded failure front. It has been observed that Mode I component of SERR primarily governs the process of adhesion failure propagation. The appropriate spar overlap length on the wingskin has been determined in order to prevent adhesion failure. Further, an attempt has been made to improve the structural integrity of the SWJ by reducing the stress concentration at the ends of spar and wingskin overlap. This has been achieved by obtaining a favourable stress distribution over the entire joint structure by using Functionally Graded Materials (FGM) in the spar and wingskin adherend instead of FRP composite panels. Exponential gradation indices have been used for material grading of the spar and wingskin adherends. It has been seen that peel and shear stresses and values of SERR components as well as total SERR reduce significantly by use of FGMs with suitable exponential material grading index. [ABSTRACT FROM AUTHOR]

The effect of Mo doping on the structural and dielectric properties has been investigated in detail for Co-Zn spinel ferrite. Solid state reaction technique has been used to prepare the CZMO. The structural analysis is performed using HRXRD technique which confirms the inverse spinel structure of the material. The frequency and temperature dependence of dielectric constant are studied which reveals that the dielectric dispersion is due to Maxwell-Wagner type polarization in agreement with Koop's phenomenological theory. The contribution of grain and grain boundary at high and low frequency respectively are evident in the dielectric constant. The variation of dielectric loss tangent with both the temperature and frequency has been studied. The room temperature and high frequency dielectric loss is observed to be very small. Also it is revealed that the dielectric loss tangent decreases with Mo substitution. [ABSTRACT FROM AUTHOR]

3D Finite Element Analyses have been carried out for Spar Wingskin Joints made with laminated Graphite Fibre Reinforced Plastic composites subjected to uniformly distributed transverse load. The delamination has been pre-embedded at the most likely location, i.e. in resin layer between the top and next ply of the fibre reinforced plastic laminated wingskin and near the spar overlap end. Multi-Point Constraint finite elements have been made use of at the vicinity of the delamination fronts. This helps in simulating the growth of the embedded delamination at both ends. The inter-laminar peel and shear stresses responsible for causing delamination damage have been evaluated. Strain energy release rate components corresponding to the Mode I (opening), Mode II (sliding) and Mode III (tearing) of delamination are determined using the principle of Virtual Crack Closure Technique. These are seen to be different and non-self-similar at the two fronts of the embedded delamination. Mode I Strain energy release rate ( G I ) primarily governs the process of delamination propagation. [ABSTRACT FROM AUTHOR]

A study was undertaken to investigate the rate of dissolution of the various Phosphorus (P) sources in an alluvial soil of Bihar under an incubation experiment in the laboratory for 35 days with 5 treatments viz., Control; RP (Rock Phosphate) @ 100% of the RDP (Recommended Dose of Phosphorus); 100% of RDF (Recommended Dose of Fertilizer NPK); REC (Rock phosphate Enriched Compost) @ 100% of the RDP and 50% RDP+REC @ 50% of the RDP. The P release pattern was determined for every treatment at a sampling interval of 7 days. The integrated treatment involving REC and P-fertilizer (50:50) performed better than other treatments. This combination released greater labile P (16.14 mgkg−1), Fe-Al-bound P (74.48 mgkg−1), and Ca bound P (147.04 mgkg−1) in soil. It could be concluded that enriched compost (50%) along with the reduced application (50%) of inorganic P fertilizer could be very helpful in supplementing the P requirement of plants by increasing its release and availability under naturally P deficient conditions. [ABSTRACT FROM AUTHOR]

Adhesive bonding techniques have increased its application in automobile industries. The most common bonded joint configuration is the lap-shear joint, which when subjected to loading shows a differential substrate straining at the overlap ends. One of the methods to improve its performance is by introducing a reverse bent angle to the adherends at the overlap area. In this paper, the parameters which affect the strength of the reverse bend joints are found out by conducting experiments on different specimens. A detailed study was carried out showing the trends in the joint performance by varying the input parameters. Preformed angle at the overlap area, overlap length, ultimate tensile strength and modulus of the substrates have shown significant effect on the improvement of strength. For most of the adherends used in the automotive industries it has been found that a 10 degree preformed reverse bend joint consistently showed a 15 percent improvement in the strength compared to the traditional lap-shear joint. A model was developed based on Artificial Neural Networking system identification methods to predict the optimum joint configuration based on the given input parameters. This can be used to design high-performance adhesive bonded joints for parts and assemblies in automotive and aerospace industries. [ABSTRACT FROM AUTHOR]

In the present study, numerical and experimental investigation of stress distribution pattern has been performed for thick walled nuclear rotor pipe joint of Alloy 617 and 10Cr steel. Hot wire Tungsten Inert Gas (HW-TIG) welding process has been adopted for multipass narrow groove welding since it yields better mechanical properties at low heat input than manual TIG welding and decreases the accumulation of residual stress significantly. The residual stress generated at the surface of the welded joint was evaluated experimentally using the Blind hole drilling technique (BHD), and consequently, the distribution of stresses along the thickness of the welded joint was masured using the Deep hole drilling (DHD) method. According to the findings, shrinkage at the HAZ area of the weld influences the stresses generated at the cylinder outer surface. The distribution of residual stresses in the weld region is driven mostly by the bending effect produced during the welding process. The influence of post weld heat treatment (PWHT) on residual stress distribution has also been investigated using both experimental and numerical approaches. Numerical investigations have been performed using ABAQUS finite element method. A 2D finite element model has been developed to simulate the welding process and the subsequent heat treatment, using coupled thermo-mechanical analysis. The residual stress results obtained from the numerical approach were validated with the experimentally obtained results and a good correlation has been found. The lumped pass model along with an equal density heat source has been implemented to minimize the computation complexity without affecting the accuracy of the simulated results. The obtained findings revealed that apart from weld centerline, hoop tensile residual stresses were higher around the buttered layer of Alloy 617 and 10Cr steel in an as-welded state. It has been found that nearly 80% of the stresses generated along the weld section have been released after PWHT. • Study of multi-pass dissimilar welded joint of rotor joint of Alloy 617 and 10Cr steel. • Experimental investigation of through thickness residual stresses in the DWJ using the deep hole drilling (DHD) method. • Evaluation of surface residual stresses using blind hole drilling (BHD) method. • Validation of experimental results using numerical analysis. [ABSTRACT FROM AUTHOR]

Dissimilar metal welds (DMW) of ferritic to austenitic stainless steel are broadly used in steam generators working in power generation industries. Frequent failure of DMWs from the heat-affected zone (HAZ) of the ferritic part necessitates structural integrity assessment of the DMWs in order to determine and extend the lifetime of these components. In this regard, typical DMWs of SA516–309L–304L and SA516–309L/308L–304L attributed to domestic reactors were fabricated under different welding conditions. The effects of conventional and narrow weld groove configurations, buttering layer, and varying buttering layer width on the through-thickness residual stress fields in the DMWs were investigated experimentally and with the help of numerical simulations. Results show that the narrow groove weld is beneficial in reducing the residual stresses in the weld zone. Incorporating an additional buttering layer in the narrow groove joint further reduced the residual stresses across the weld joint. A 6 mm thick buttering layer was found to be competent enough to minimize the residual stresses dispersed across the weld cross-section. • Narrow weld groove exhibits reduction in residual stresses in weld zone. • Additional buttering layer reduced the level of residual stresses across the weld zone. • A 6 mm thick buttering layer was found to be competent enough. [ABSTRACT FROM AUTHOR]

In this paper, frequency dependent dielectric parameters of pure oils and nanofluids have been studied at different temperatures to investigate any improvement of the dielectric properties due to the presence of nanoparticles. In power transformers, mineral oil is popularly used as an insulating material. However, mineral oils have inherent drawbacks associated with fire hazards and environmental issues. So, as an alternative, vegetable oils are drawing more attention of the researchers in this field. But, pure vegetable oil exhibits weak dielectric properties to be used under high electric stresses. Considering the drawbacks, extensive research work is going on to improve the dielectric strength of eco-friendly vegetable oils by using nanoparticles as additives. In this work, nanoparticles (TiO 2 and Al 2 O 3) based mineral and vegetable (FR3) oil samples have been prepared in laboratory for investigation of their dielectric properties for use in high voltage equipment through frequency domain spectroscopy. The dielectric dissipation factors obtained from FDS measurement have been compared for the aforesaid liquids. Furthermore, frequency domain spectroscopy has been conducted on pure oils and nanofluids at different temperatures to study the effect of temperature on their dielectric properties. Based on the experimental results, LFD of the insulation has been investigated to obtain an idea about aging status of it. • TiO 2 and Al 2 O 3 based nanofluids have been prepared in laboratory. • Temperature effects on Dielectric properties of Mineral and vegetable oil based nanofluids upto 90 °C. • Frequency Domain Spectroscopy has been conducted for different nanofluids at different temperatures. • Corelation between tanδ losses and low frequency dispersion (ΔC) has been proposed. [ABSTRACT FROM AUTHOR]

Abstract Ni-B coatings are promising materials for several applications in electronics, nuclear, automotive, aerospace, petrochemical and food industries owing to their exceptional mechanical and chemical properties such as, high hardness, high wear resistance and good corrosion resistance. However, the literature indicates that there is still significant scope for further improvement in properties of these coatings in order to improve their in-service performance and/or total service life. Considering this fact, a novel Ni-B-Tl 2 O 3 composite coatings has been developed via electrodeposition technique by reinforcing Tl 2 O 3 particles into the Ni-B matrix. The effect of addition of Tl 2 O 3 particles on the morphology, structure and electrochemical properties of Ni-B-Tl 2 O 3 coatings was investigated and compared with that of the Ni-B coatings. A substantial change on surface roughness, thermal properties, crystal structure, mechanical properties and corrosion resistance was observed due to the addition of Tl 2 O 3 particles to the Ni-B coatings. The as-deposited Ni-B coatings were found to be amorphous in nature, however the crystallinity of the composite coatings was significantly improved by the addition of the Tl 2 O 3 particles. Surface analyses showed an increase in surface roughness due to the addition of Tl 2 O 3 particles, which confirms the formation of fine and dense structures in both Ni-B and Ni-B- Tl 2 O 3 coatings. There is significant improvement in microhardness (by 80%) and elastic modulus (by 60%) of Ni-B-Tl2O 3 composite coatings as compared to Ni-B coatings mainly due to the addition of Tl 2 O 3 particles. Corrosion resistance was found to be improved significantly after the incorporation of Tl 2 O 3 into the Ni-B matrix which may be attributed to reduction in active area of Ni-B matrix. Highlights • Ni-B-Tl 2 O 3 composite coatings have successfully been electrodeposited. • Addition of Tl 2 O 3 has been observed to improve crystallinity of Ni-B coating. • Addition of Tl 2 O 3 has resulted in a significant change in surface morphology. • Ni-B-Tl 2 O 3 coating exhibited significant improvement in mechanical properties. • Ni-B-Tl 2 O 3 coating exhibited almost three times increase in corrosion resistance. [ABSTRACT FROM AUTHOR]

Toxoplasmosis is a worldwide zoonosis. The ingestion of uncooked/undercooked meat and consumption of water contaminated with Toxoplasma gondii oocysts excreted by felids are the main modes of transmission of this parasite. T. gondii has been reported in multiple cervid species; however, little is known of the parasite in North American elk ( Cervus canadensis ). In the present study, antibodies to T. gondii were detected in serum of wild elk from Pennsylvania collected during 2013–2016 by the modified agglutination test (MAT, cut-off 1:25); 221 of 317 (69.7%) had MAT titers of 1:25 in 19, 1:50 in 28, 1:100 in 34, and 1:200 or higher in 140. Thus most (44.1%) elk had relatively high titers. Seroprevalence was slightly higher in males (76.9%) than females (67.5%, not statistically significant, Chi-square tests, P < 0.0001) and was higher in adults (76.5%) than yearlings (46.4%, Odds ratio 3.82; 95% CL 1.72–8.47; P = 0.001) or calves (21.7%, Odds ratio 12.58; 95% CL 4.51–35.10; P < 0.0001). Annual seroprevalence was relatively stable throughout the period tested and ranged from 66.6% to 72.2%. Of the 101 elk harvested in 2016, hearts were bioassayed from 20 elk and tongues were bioassayed from 56; all tongue samples were negative. Viable T. gondii was isolated from hearts of two female elk, one of these was a seronegative adult and the other was a calf with no serum available for testing. Both T. gondii isolates were cultivated in cell culture and DNA derived from tachyzoites was characterized using the PCR-RFLP markers including SAG1, SAG2 (5′- 3′SAG2 and altSAG2), SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, and Apico. One isolate belongs to ToxoDB PCR-RFLP genotype #2 and the other is genotype #5. Both genotypes are frequently identified in animals in North America. [ABSTRACT FROM AUTHOR]

We have optimized Gd ion substitution in BiFeO 3 (BFO) and observed prominently change in structural, electrical and magnetic behavior of Bi 1+2x Gd 2x/2 Fe 1−2x O 3 ceramics synthesized through slow step sintering schedule. It is observed that with the increase in concentration of Gd (x=0.1), original structure of BFO is transformed from rhombohedral R 3 c space group to orthorhombic Pn 21 a space group. Surprisingly, unit cell volume is drastically contracted (35% for x=0.2) and the sintered specimen showed enhanced room temperature ferromagnetic behavior although the original BFO is normally G-type antiferromagnetic in nature at 643 K. It is expected that intrinsic chemical pressure within the bulk body built by the substitution of Gd in presence of excess bismuth greatly supported through unidirectional movement of electrical dipole moment with in each individual domain as a result of which suppression of leakage current with enhanced dielectric and ferroelectric hysteresis is observed. [ABSTRACT FROM AUTHOR]

• Tissue cyst formation in pork of 8 pigs was studied by mouse bioassay 7 and 14 days after infection with Toxoplasma gondii. • Bioassay of 5, 10, 50 g samples of meat revealed uneven distribution of tissue cysts. Among the meat sources of Toxoplasma gondii , pork is considered important in the epidemiology of toxoplasmosis in the USA. How soon after infection T. gondii forms tissue cysts in pork is unknown. In the present study, eight serologically negative ˜ 3 months old pigs were fed mouse tissues infected with VEG (Type III) strain of T. gondii and euthanized 7 (4 pigs) and 14 days (4 pigs) post-inoculation (p.i.). Meat from the right shoulder of each pig was bioassayed in mice for T. gondii tissue cysts by peptic digestion. From each pig, the shoulder muscle was cut at random spots into 5 g, 10 g and 50 g portions. Extreme care was taken to use different scalpels and forceps to minimize cross contamination among 17 samples (6 replicates of each 5 g and 10 g portions and 5 replicates of 50 g). From the four pigs euthanized at 7 days p.i., a composite of ˜ 200 g of leftover meat from each shoulder was bioassayed in cats and their feces were tested for oocyst excretion. All eight pigs developed T. gondii antibodies (modified agglutination test, MAT, 1: 80 or higher) and viable T. gondii was isolated from shoulder meat of each pig. All four cats fed pork from excreted T. gondii oocysts. The density of T. gondii , based on mouse infectivity, varied within 5–50 g samples each pig, and between pigs within the same group, day 7 versus day 14 p.i. There were no significant differences in mouse bioassay results obtained with day 7 versus day 14 infected pigs. Overall, the rate of isolation of T. gondii increased with sample size of meat bioassayed. Results demonstrate that tissue cysts are formed early in infection and they are unevenly distributed. [ABSTRACT FROM AUTHOR]

Cats are important in the epidemiology of toxoplasmosis because they are the only definitive hosts that excrete environmentally resistant Toxoplasma gondii oocysts. Little is known of feline toxoplasmosis in China and most of the literature is in Chinese. Here we summarized all published reports on feline toxoplasmosis in English and report first identification of oocyst excretion by naturally infected cats in China. Unfrozen tissues of 42 cats and feces of 360 cats from China were bioassayed in mice for isolation of T. gondii . Antibodies to T. gondii were found in 21 of 42 (50%) of cats by the modified agglutination test (cut-off 1:25). Viable T. gondii was isolated from tissues of eight of 21 seropositive but not from 21 seronegative (<1:25) cats. Viable T. gondii was isolated from feces of one cat. DNA derived from cell cultured tachyzoites of all nine T. gondii isolates was characterized by PCR–RFLP at 10 loci (SAG1, SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, and Apico). Four genotypes were found; the genotypes of tissue isolates were ToxoDB #9 in six, ToxoDB #2 in one, and ToxoDB #17 in one. The fecal isolate was ToxoDB #1.To our knowledge, the present study is the first isolation of T. gondii from cat feces from China. [ABSTRACT FROM AUTHOR]