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Recent studies have demonstrated the efficacy of deep learning architectures in enhancing the interpretation of skin images, thereby aiding in the classification and segmentation of skin cancer. However, the existing deep learning techniques predominantly focus on either segmentation or classification and are designed for normally distributed data. Addressing this limitation, the present study introduces a hybrid ensemble deep learning approach for skin cancer classification and segmentation. This proposed model amalgamates Residual Learning Machines, Swin Transformers, and Fast Neural Networks (FNN) to proficiently manage diverse sets of non-uniformly distributed data, thereby augmenting diagnostic accuracy. The efficacy of this approach was evaluated using various skin cancer datasets, including ISIC-2008, PH-2, and HM007. The assessment involved several performance metrics, such as the Matthew correlation coefficient (MCC), recall, F1-score, specificity, accuracy, and precision. Moreover, to underscore the superiority of the proposed model, its performance was juxtaposed with that of previous efforts. Results from repeated trials indicate that the proposed model achieved 98.78% classification accuracy, 98.7% precision, 98.7% F1-score, 98.64% average recall, and an MCC of 0.9863 across different skin disease datasets. Demonstrating consistent superiority over existing methods, the proposed approach shows considerable potential in revolutionizing the diagnostics of skin cancer. [ABSTRACT FROM AUTHOR]

Recent studies have demonstrated the efficacy of deep learning architectures in enhancing the interpretation of skin images, thereby aiding in the classification and segmentation of skin cancer. However, the existing deep learning techniques predominantly focus on either segmentation or classification and are designed for normally distributed data. Addressing this limitation, the present study introduces a hybrid ensemble deep learning approach for skin cancer classification and segmentation. This proposed model amalgamates Residual Learning Machines, Swin Transformers, and Fast Neural Networks (FNN) to proficiently manage diverse sets of non-uniformly distributed data, thereby augmenting diagnostic accuracy. The efficacy of this approach was evaluated using various skin cancer datasets, including ISIC-2008, PH-2, and HM007. The assessment involved several performance metrics, such as the Matthew correlation coefficient (MCC), recall, F1-score, specificity, accuracy, and precision. Moreover, to underscore the superiority of the proposed model, its performance was juxtaposed with that of previous efforts. Results from repeated trials indicate that the proposed model achieved 98.78% classification accuracy, 98.7% precision, 98.7% F1-score, 98.64% average recall, and an MCC of 0.9863 across different skin disease datasets. Demonstrating consistent superiority over existing methods, the proposed approach shows considerable potential in revolutionizing the diagnostics of skin cancer. [ABSTRACT FROM AUTHOR]

Hot cracking free fusion welds of re-sulphurized, high machinable grade stainless steel AISI 416 were obtained while adopting Laser-arc Hybrid Welding (LAHW) with the use of Ni-Cr-Mo rich austenitic filler metal. The carbon enriched martensite was observed at the interface of weld region, which, in turn, contributed for an elevated hardness. Both gamma ray non-destructive testing and cross-sectional analysis further affirm the absence of porosity and solidification cracking in the weld region of AISI 416. Mechanical integrity of the joints were established using tension and Charpy V-notch impact tests. Notch tensile studies revealed that the joint strength was much higher compared to the base metal. A slight delineation in notch impact toughness of the LAHW joints is ascribed to the formation of sulphide inclusions. The outcomes of the study recommend the use of the LAHW for joining difficult-to-weld metals. [ABSTRACT FROM AUTHOR]

The fusion zone microstructure and mechanical properties of UNS S32750 joints obtained from gas tungsten arc (GTA), gas metal arc (GMA) and flux cored arc (FCA) welding processes were investigated. The formation of grain boundary, Widmanstätten and intragranular austenite were observed in the fusion zone of the weldments. Electron back scattered diffraction (EBSD) analysis confirmed the presence of chi (ψ) and sigma (σ) phases in the reheated fusion zones of all the weldments. Tensile failures occurred at the fusion zone for all the weldments and the joint efficiency was found to be greater for GTA welds than the others. The number of welding passes and heat input had a significant impact on the ferrite: austenite ratio. FCA weldments experienced inferior notch toughness at both room temperature and sub-zero temperature owing to the prominent amount of secondary austenite and precipitation of intermetallic phases compared to the other weldments. [ABSTRACT FROM AUTHOR]

The microstructure traits and structural integrity of Ti-6Al-4 V welds of 5 mm thickness are discussed. The use of activated flux in the tungsten inert gas (ATIG) welding technique is adopted in this study using the oxide surfactant. Bead on trials attested that the depth of penetration (DOP) is enhanced with a corresponding rise in welding current upon the use of oxide surfactant. Microstructure studies depicted the presence of acicular α’ structure of martensitic needles and Widmanstätten α platelets with β-Ti grain boundaries throughout the fusion zone. Tensile studies indicated that the strength of the joints of ATIG welds was better, as the failures were experienced in the parent metal. The impact toughness of the ATIG weldments was insignificantly reduced when compared to the base metal owing to the coarsened grains in the weld zone. The findings of this study attests the use of low cost welding technique for joining Ti-6Al-4 V of 5 mm thickness for improved properties. [ABSTRACT FROM AUTHOR]

The present study addresses the effect of fillers on the microstructure and tensile strength of dissimilar joints of Inconel 625 and UNS S32205 by pulsed current gas tungsten arc welding (PCGTAW) employing ERNiCrMo-10 and ERNiCrMo-14 fillers. This study attested that tensile failure occurred in the fusion zone of the dissimilar joints for both the cases in the as-welded un-peened condition. Double shot laser shock peening (DLSP) was performed on the fusion zone of these PCGTA welds on the cap and root regions of the weldments. It was assimilated that after DLSP on the cap and root regions of the weldments, the yield and tensile strength of the welded joints employing these fillers were improved considerably. Residual stress analysis were carried out on the dissimilar coupons using X-ray Diffraction analysis. The results demonstrated that after subjecting to double sided DLSP, the fusion zones were subjected to compressive residual stresses. The present study articulated that shot peening using low energy laser beam resulted in better tensile strength. [ABSTRACT FROM AUTHOR]

This study addresses the effect of post weld heat treatment on the fusion zone microstructure and the mechanical properties of activated flux tungsten inert gas (A-TIG) weldments of Inconel X750. In this study, a compound flux of 50% SiO 2 +50% MoO 3 was used for A-TIG welding of the samples. Comparative studies on the microstructure and mechanical properties have been made on the weldments both in the as-welded and post weld heat treated conditions. Direct ageing post weld heat treatment (PWHT) was carried out at 705 °C for 22 h on the A-TIG weldment to assess the structure–property relationships. It was inferred that direct ageing post weld heat treatment resulted in better tensile strength (1142 MPa) compared to the as-welded coupons (736 MPa). The joint efficiencies of the as-welded and post weld heat treated conditions were found to be 60.7% and 94.07% respectively. The impact toughness of the as-welded coupons were found to be greater than the post weld heat treated samples; however the impact toughness of the welds are greater than the parent metal employed in both the cases. This study also attested the detailed structure–property relationships of A-TIG weldments using the combined techniques of optical and scanning electron microscopy, Electron Dispersive X-ray Analysis (EDAX) techniques. [ABSTRACT FROM AUTHOR]

This research work articulates the microstructural features of the dissimilar weldments involving Ni based superalloy Inconel 718 and martensitic stainless steel, AISI 416 that is difficult to weld. Autogenous tungsten inert gas (TIG) welding was carried out with and without using flux to fabricate these bimetallic combinations. Microstructure at the fusion zones and the interfaces were characterized using optical and scanning electron microscopy. The results depicted the presence of fine martensite at the heat affected zone (HAZ) of AISI 416 and the formation of unmixed zone containing secondary phases at the HAZ of Inconel 718. Similarly, the formation of Nb rich eutectics along with sulfides was witnessed at the fusion zone of both the weldments. Owing to the low heat input witnessed during the flux assisted TIG welding, the Nb segregation was found to be minimal. Tensile studies reported that the fracture occurred at the fusion zone in both the cases. It was inferred from the tensile studies that the joint strength of the weldments with flux addition was greater than the ones without flux. This study demonstrated that dissimilar joints with complete penetration could be achieved in single pass using the TIG welding process with the aid of flux. [ABSTRACT FROM AUTHOR]

This research article addresses the joining of 5 mm thick plates of Inconel 718 by activated flux tungsten inert gas (A-TIG) welding process using SiO 2 and TiO 2 fluxes. Microstructure studies inferred the presence of Nb rich eutectics and/or laves phase in the fusion zone of the A-TIG weldments. Tensile studies corroborated that the ultimate tensile strength of TiO 2 flux assisted weldments (885 MPa) was better compared to SiO 2 flux assisted weldments (815 MPa) and the failure was observed in the parent metal for both the cases. Impact test results portrayed that both the weldments were inferior in toughness as compared to the parent metal, which was due to the presence of oxide inclusions. Also, the study investigated the structure–property relationships of the A-TIG weldments of Inconel 718. [ABSTRACT FROM AUTHOR]

This research work articulated the effect of SiO 2 flux assisted tungsten inert gas (TIG) welding on the microstructure and mechanical properties of marine grade stainless steel weldments, such as super-duplex stainless steel (UNS S32750) and austenitic stainless steel (AISI 316L). The studies showed that the use of flux decreased the heat input required to obtain complete penetration. Microstructure studies revealed the presence of ferrite at the heat affected zone of AISI 316L and the fusion zone which obviated the hot cracking tendency. Tensile studies corroborated that the joint strength was sufficiently greater than that of the parent metals. Impact toughness slightly impoverished owing to the presence of large platelets of Widmanstätten austenite in the fusion zone. The study also explored the structure–property relationships of the flux assisted weldments using the combined techniques of optical and scanning electron microscopy analysis. Owing to the better metallurgical and mechanical properties, this study recommends the use of SiO 2 flux for joining the dissimilar metals involving austenitic and super-duplex stainless steels. [ABSTRACT FROM AUTHOR]

This study addresses the comparison of metallurgical and mechanical properties of autogeneous and activated compound flux assisted gas tungsten arc welding (GTAW) of super-austenitic stainless steel, AISI 904L. The use of compound flux containing 85% SiO 2 –15% TiO 2 acquainted for better depth of penetration compared to autogeneous welding. Segregation of Mo rich phases was witnessed in the fusion zone of flux assisted AISI 904L. Tensile studies showed that the fracture occurred at the fusion zone for both the weldments. Ductility was found to be greater for the flux-assisted weldments. The present study also investigates the structure–property relationships of AISI 904L weldments using the combined techniques of optical and scanning electron microscopy. [ABSTRACT FROM AUTHOR]

The metallurgical and mechanical properties of electron beam welded Ni based superalloy Inconel 625 and UNS S32205 duplex stainless steel plates have been investigated in the present study. Interface microstructure studies divulged the absence of any grain coarsening effects or the formation of any secondary phases at the heat affected zone (HAZ) of the electron beam (EB) weldments. Tensile studies showed that the fracture occurred at the weld zone in all the trials and the average weld strength was reported to be 850 MPa. Segregation of Mo rich phases was witnessed at the inter-dendritic arms of the fusion zone. The study recommended the use of EB welding for joining these dissimilar metals by providing detailed structure – property relationships. [ABSTRACT FROM AUTHOR]

In the present investigation, an attempt has been made to weld the precipitation hardened Nickel based super alloy Inconel 718 and austenitic stainless steel AISI 316L using Continuous Current Gas Tungsten Arc Welding (CCGTAW) and Pulsed Current Gas Tungsten Arc Welding (PCGTAW) process employing ER2553 and ERNiCu-7 fillers. Microstructure examination using optical and SEM analysis clearly witnessed the formation of unmixed zone at the Heat Affected Zone (HAZ) of Inconel 718 for all the joints. The studies showed the absence of deleterious phases in the CCGTA and PCGTA weldments employing ERNiCu-7. Tensile studies corroborated that the fracture occurred at the parent metal of AISI 316L in all the cases. It was inferred from the present study that PCGTA weldments employing ERNiCu-7 exhibited better metallurgical and mechanical properties. This study articulated the effect of filler metals on the structure-property relationships of the weldments. [ABSTRACT FROM AUTHOR]

Highlights: [•] Effect of filler metals on the weldability of super-duplex stainless steel plates. [•] Contemplative explanations on the metallurgical and mechanical properties of the weldments. [•] Enhanced mechanical properties of the welds at ambient room temperature. [ABSTRACT FROM AUTHOR]

Abstract: Dissimilar metal welding involving AISI 304 and Monel 400 finds widespread use in marine and offshore environments for the fabrication of heat exchangers, evaporators, piping and vessels in petrochemical and power generation industries. However studies on the performance of such weldments are scantly found in the literature even though the individual metals have higher corrosion resistance and strength. This paper reports the work carried out on welding of AISI 304 and Monel 400 using Gas Tungsten Arc Welding (GTAW) technique to examine the weldability, mechanical and metallurgical properties. Investigations have been carried out on the hot corrosion behavior of these joints subjected to cyclic air oxidation and K2SO4 +NaCl (60%) molten salt environment at 600°C. A comparative analysis was carried out on these weldments for two different filler metals such as E309L and ENiCu-7. The oxide scales formed on the various zones of the weldment have been characterized systematically using surface analytical techniques. Weld zone was found to be more susceptible to degradation than base metals used. The effect of filler materials on the hot corrosion is discussed. The studies reported in this paper would be beneficial for fabricators embracing this type of dissimilar weldments in the petrochemical and power generation industries. [Copyright &y& Elsevier]

Abstract: The local (plate)/global (beam) vibration and damping behavior of composite thin-walled box member subjected to vibratory environment are studied and presented in this paper. This investigation is carried out by the use of 3D beam and thin plate finite elements and the corresponding modal frequencies/damping values of composite box beam are predicted by modal strain energy method. Application examples illustrate the ability of the 3D beam and thin plate element to predict both local and global modal frequencies/damping of hollow box sections. The influence of L/h ratio, b/h ratio and ply angle on the frequency and loss factor of composite box beam is investigated. In addition, an attempt has also been made to investigate the effect of temperature on the composite damping characteristics of rectangular box type section. [Copyright &y& Elsevier]

Abstract: In this paper, vibration and damping of composite sandwich box column containing viscoelastic layer (VEL) or electrorheological fluid (ER) core with constraining layer and their performance comparison is carried out. The finite element based modal strain energy method is used for predicting the modal loss factor and frequency of laminated composite box columns with integral viscoelastic/ER fluid layers. Effects of core thickness, orientation of the fiber in the base plate and constraining layer, applied voltage and stacking sequence on the vibration behavior of composite sandwich box column for clamped-free boundary condition are studied in the paper. The performance comparison of vicsoelastic layer damping and ER layer damping is also investigated. [Copyright &y& Elsevier]

• The article is focused on improving the performance of data transmission in wireless sensor network. The highlights of the research are as follows. • Active relay nodes are identified with fuzzy logic and utility factor. • Coverage distance is measured with Received Signal Strength (RSS) • The fuzzy inference system selects the next relay node according to the coverage distance, energy and utility factor and bandwidth availability factors. • By choosing relay node according to the above mentioned factors, the data transmission performance is improved. Numerous sensor nodes are getting utilized in the field of Wireless Sensor Network (WSN) for complex communication. In the recent scenario, there is a lack in the number of sensor node placement with less sensing and communication capabilities. There is less involvement with the characteristics of sensor nodes for direct communication with remote nodes. During the communication, sensor data are communicated to the sink with the help of sensor hubs. Therefore to improve the performance of QoS, routing in the integration of relay node selection plays an important role in WSN. In this paper, we propose Fuzzy based Relay Node Selection and Energy Efficient Routing (FRNSEER) make the routing more efficient by selecting the effective relay node while communicating with the sink node. For selecting the sink node, fuzzy rules are used where active relay nodes are selected as the outcome. The active relay node selection helps to determine the better energy and utility factor during the transmission process. To make better communication between the relay node and the sink node, sensor hubs are used with a lower energy expenditure schedule with expected functions of neighbor/working nodes. In the performance analysis, the proposed mechanism will perform better in terms of packet rate with low energy consumption compared to the existing algorithms such as Fuzzy-based Hyper Round Policy (FHRP) and Neural Network-based Localisation Scheme (NNBLS). [Display omitted] [ABSTRACT FROM AUTHOR]

Abstract: This article attempts to relate ultrasonic second harmonic generation to dislocation structures in fatigued materials. By focusing on the fact that asymmetric dislocation motion is required to generate the second harmonic, a theoretical derivation of the non-linearity parameter (ratio of the amplitude of second harmonic to square of the amplitude of the fundamental) from dislocation pile-ups is presented. In order to verify the theory, harmonic generation was measured along a failed fatigue sample of DA718, a nickel base superalloy that exhibits planar slip, and consequently dislocation pile-ups. TEM studies along the length of the failed fatigue sample revealed a banded dislocation structure, composed of pile-ups near the fracture zone and a sparse dislocation network closer to the grip region. The non-linearity parameter was found to increase by between 90% and 140% from the grip region to the fracture zone and this correlated well with the calculations based on theoretical expressions derived here. [Copyright &y& Elsevier]

Much work has been carried out in the general area of hot deformation and more specifically in the understanding and descriptions of the flow response that is observed under conditions that characterise hot deformation. Yet, the issue of the effects of energy dissipated on the metallurgical changes has not been found to be resolved successfully. The systems modelling approach of the dynamic materials model (DMM) has been extended to a study of the stress–strain curve. Definition of a parameter called the energy storage ratio (ESR) enables tracking of the metallurgical processes that underlie the stress–strain curve. It is established that the onset of dynamic recrystallisation corresponds to a constant critical value of the ESR which is independent of strain rate and temperature. [Copyright &y& Elsevier]

The precipitation effects on the mechanical behavior of electron beam welded joints of Inconel 625 in the as-welded [AW] and post-weld heat treatment [PWHT] conditions have been investigated in this research study. A PWHT comprising of direct aging [DA] treatment at 700 °C for 100 h in vacuum at a pressure of 10−5 mbar was performed on the weld joints. The microstructure of the base alloy opined the precipitation of MC system carbides and γ′′ strengthening phase after subjecting to DA. Also, Nb–Mo rich precipitates and the Laves phase was noticed in the inter-dendritic arms of the fusion zone (FZ) of welded joints in the AW conditions. DA treatment has a notable effect on the weld mechanical characteristics of Inconel 625 joints. The precipitation of γ′′ strengthening phase is reasoned for the significant rise in the yield strength [YS] and tensile strength [TS] of the base alloy and EBW joints. • Grain boundary precipitation of MC carbides on EB weld seams of Incoloy 925. • Formation of M 23 C 6 , M 6 C carbides in the grain boundaries of weld microstructures in both the conditions. • Improved yield and tensile strengths after subjecting to PWHT conditions. [ABSTRACT FROM AUTHOR]

The pulsating current approach in tungsten inert gas (TIG) welding is adapted for joining Hastelloy C-276. Microstructure examination revealed the absence of micro-segregation while employing UNS N06022 filler. Due to the prevalence of higher tensile stresses in the un-peened conditions, tensile failures were observed in the weld regions of both the joints irrespective of fillers. Low energy laser shock peening without coating (LSPwC) was carried out on the weld zones on both the sides of the joints with the pulse densities 2500 and 7500 pulses per cm2. This laser surface treatment had remarkably increased the tensile strength of the welded joints by shifting the location of tensile failures well away from the fusion zones for all the cases. Similarly, a considerable increase is observed in the notch toughness of both the joints in the LSPwC condition. The enhancement in tensile strength and notch impact toughness of the welds could be ascribed to the residual compressive stresses induced which were then confirmed by Sin2ψ method in X-ray diffraction (XRD) technique. [ABSTRACT FROM AUTHOR]

This investigation presents a fault diagnosis methodology for detecting sensor faults in cement industries pyro processing section. It works in three steps: (a) modelling, (b) analysis, and (c) validation. In the modelling, the actual data from the cement pyro processing is used to do a correlation analysis between output and input variables. The structural model is obtained from the correlation tests. During the analysis phase the Structural analysis Tool (SaTool) is used to detect the detectability and isolability of the faults. The results of the structural analysis are validated in a cement industry using residual analysis performed using structural sensor model and real-time measurements. The main advantages of this fault diagnosis technique are: (a) it requires only correlation analysis to obtain the structural model without a detailed physical model as in other methods, (b) conclusions regarding detectability and isolability can be easily drawn during the analysis stage itself, and (c) the method is simple compared to the model-based, and data-history based methods. The effectiveness of the proposed method is illustrated using data from cement pyro processing plant and its performance is compared with model based approaches for four different types of sensor faults: (1) bias, (2) drift, (3) stuck, and (4) measurement failures. Our results demonstrate that the structural method is able to detect the sensor faults even in the presence of noisy information, and its performance is comparable with that of model based approaches without employing a physical model. [ABSTRACT FROM AUTHOR]

: ObjectivesIn light of evidence that some complications of diabetes mellitus may be caused or exacerbated by oxidative damage, we investigated the effect of Gymnema montanum leaf extract (GLEt) on tissue antioxidant defense systems in alloxan-induced diabetes in rats.: MethodsGLEt was administered orally at a doses of 50, 100, and 200 mg/kg of body weight for 30 d, after which liver and kidney tissues were assayed for the degree of lipid peroxidation by means of markers, reduced glutathione content and activities of catalase, superoxide dismutase, glutathione peroxidase, and glutathione-S-transferase.: ResultsTreatment of diabetic rats with GLEt increased the antioxidant levels. Liver and kidney from diabetic animals exhibited disturbances in antioxidant defense when compared with normal rats. GLEt at a dose of 200 mg/kg of body weight exhibited a significant effect as compared with 50 and 100 mg/kg of body weight. These effects were compared with glibenclamide, a reference drug.: ConclusionsIt may be concluded that, in diabetes, liver and kidney tissues are more vulnerable to oxidative stress and show increased lipid peroxidation. The antioxidant responsiveness mediated by G. montanum may be anticipated to have biological significance in eliminating reactive free radicals that may otherwise affect normal cell functioning and provide a scientific rationale for the use of G. montanum as an antidiabetic plant. [Copyright &y& Elsevier]

A wall component of super-duplex stainless steel was developed using cold metal transfer (CMT)-based wire + arc additive manufacturing (WAAM) technique with an ER2594 wire. The microstructure of the as-deposited wall was explored using optical microscopy and electron backscattered x-ray diffraction (EBSD) analysis. Ferrite count analysis indicated that the austenite-ferrite phase balance was altered along the as-deposited wall body. The average ferrite count near the as-deposited wall was 24.5%, compared with 32.3% in the root region. Widmanstätten and grain boundary austenite were formed near the wall boundary, and intragranular austenite was observed in the different layers. Secondary austenite in the transition layer was also observed. EBSD analysis revealed the sigma (σ) phase and austeno-ferritic phases across the WAAM wall. The tensile and yield strengths of the samples of the as-developed WAAM wall were almost identical regardless of orientations/tropism. Unlabelled Image • CMT based WAAM technique was adopted to develop thick wall structure of ER2594. • The yield and tensile strengths of the WAAM joints were greater than those of the cast SDSS 6A in the ASTM A 890 standard. • The austeno-ferrite phase balance was greatly affected due to complex thermal cycles of WAAM. [ABSTRACT FROM AUTHOR]

• The base alloy and weld seams of UNS S32750 are not immune to bacterial corrosion. • Accelerated pitting corrosion was experienced in the base alloy and FCA weld seams. • Pensive discussion on MIC behaviour due to microstructure changes. This study investigates the microbial-influenced corrosion of UNS S32750 super-duplex stainless-steel joints fabricated using different welding methods. Herein, the samples were introduced into a medium inoculated with Macrococcus equipercicus isolated from a marine environment. Confocal laser scanning microscopy and atomic force microscopy were used to characterise the topography and formation of pits in the corroded samples, respectively. Potentiodynamic polarisation studies were conducted on both the base alloy and weld seams exposed for 30 and 60 days in the experimental system inoculated with M. equipercicus and un-inoculated system. Results indicate that the thickness of the biofilm formed due to this bacterium increased and became heterogeneous with an increase in the exposure time, thereby resulting in micro-pits. Bacterial colonisation was observed in all the coupons after exposure to the inoculated medium. Although micro-pits were observed in all the coupons, the base metal and flux-cored arc weld seams showed highest sensitivity to bacterial attack. [ABSTRACT FROM AUTHOR]

• Similar joining of alloy 625 was employed using ERNiCrMo-4 fillers by Pulsed GTA method. • Oxidation and corrosion studies were performed on the weldment at 700 °C. • Kinetics of weldments was expressed by the thermogravimetric method. • Oxide scale formation and damage mechanism were derived. Alloy 625 joining was employed by pulsing current gas tungsten arc (PCGTA) welding method using ERNiCrMo-4 filler wire. The cyclic high-temperature performance of the weldments was investigated at 700 °C in molten salt (MS) K 2 SO 4 -60 %NaCl and air environment. The weldments' corrosion kinetics were accessed by the weight change method. A thin scale with no significant failure was found on the surface of the oxidized weldment. The oxide scale cracking and spallation occurred on the weldment in MS condition due to the deposited salts. The damage mechanism of the scales developed on the weldments is discussed in MS condition. [ABSTRACT FROM AUTHOR]

Abstract: Simulated hypobaric hypoxia (HBH), resembling high altitude hypoxia severely affects the CNS and results in several physiological changes. The hippocampus is closely associated with learning and memory and an insult to this region affects cognition. Previous studies suggest that rapid or prolonged exposures to HBH are associated with psychomotor and cognitive impairments. The defense personnel, mountain climbers and rescue teams are exposed to such harsh environment and thus it demands a systematic study emphasizing the subtle effects of such extreme environments on cognitive function. Accordingly, this study evaluated the effect of hypobaric hypoxia on structural changes in the principal neurons of the hippocampus and learning in eight-arm radial maze. Adult male Wistar rats, subjected to simulated hypobaric hypoxia equivalent to an altitude of 6000 m for a period of 2 or 7 days, in a hypoxic chamber served as hypoxic group (HY). Rats housed in a similar chamber for the same period of time, without hypoxic exposure served as sham control (SC), while normal control (NC) group of rats were housed in standard laboratory conditions. The dendritic morphology of neurons in cornu ammonis region 1 (CA1) and cornu ammonis region 3 (CA3) was studied in Golgi-impregnated hippocampal sections. Exposure for 2 days to hypobaric hypoxia had minimal deleterious effects on the CA1 pyramidal neurons, while exposure for 7 days resulted in a significant decrease in the number of branching points, intersections and dendritic length. Unlike the CA1 pyramidal neurons, the CA3 neurons exhibited dendritic atrophy following both 2 and 7 days of hypoxic exposure. Further, hippocampal-dependent spatial learning was affected marginally following 2 day exposure, while 7 day exposure severely affected learning of the partially baited radial arm maze task. Our study suggests that dendritic atrophy in the hippocampus on exposure to HBH could be one of the bases for the cognitive deficits exhibited under such conditions. [Copyright &y& Elsevier]