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In this paper, three kinds of Ni–20Cr coatings were deposited on SA516 substrate steel by cold-sprayed coating technique. Physical properties (such as hardness, surface roughness, and residual stress) and slurry erosion behavior (with impingement angles of 30∘ and 90∘) of cold-sprayed substrates have been evaluated. Moreover, a scanning electron microscope (SEM) examination has been performed to evaluate the morphological characterization of various coatings. It has been found that the residual stresses induced in the coated specimens exhibited compressive nature. Further, micro-hardness and surface roughness was observed to proliferate with the incorporation of titanium carbide (TiC) and rhenium (Re) in Ni–Cr coatings. Micro-hardness for Ni–20Cr+TiC and Ni–20Cr+TiC+Re was observed at 233.67 and 278.9 Hv, respectively, where Surface roughness for Ni–20Cr+TiC and Ni–20Cr+TiC+Re was observed at 9.86 and 11.68[Formula: see text][Formula: see text]m, respectively. All types of Ni–20Cr coatings were quite efficient in reducing the erosion rate of the SA516 steel as compared to uncoated SA516 and most prominent of all was Ni–20Cr+Tic+Re coating. It was observed that at 30∘, weight loss for Ni–20Cr, Ni–20Cr+TiC and Ni–20Cr+TiC+Re was up to 0.00027, 0.00015 and 0.00012 g/mm2, whereas at 90∘, weight loss was for Ni–20Cr, Ni–20Cr+TiC and Ni–20Cr+TiC+Re was up to 0.00024, 0.00014 and 0.00012 g/mm2.

A checklist of Cyanobacteria (Blue-green algae) has been made by reviewing available literature in order to contribute to the knowledge of biodiversity of algae in the Punjab state of India. The list records 317 taxa of the phylum Cyanobacteria distributed among 74 genera, 32 families, and six orders. The order Oscillatoriales has 115 taxa, followed by Nostocales (84), Synechococcales (60), Chroococcales (49), Spirulinales (8), and Pleurocapsales (1). The family Nostocaceae has the maximum number of genera followed by Microcoleaceae, Chroococcaceae, Oscillatoriaceae and other reported families. The genera with the highest number of species were Phormidium (39 species), Lyngbya (15 species), Oscillatoria (14 species), and Leptolyngbya & Scytonema (13 species each). The checklist revealed a high degree of species richness within phylum Cyanobacteria found in Punjab. This checklist can provide a baseline for future floristic studies with taxonomically updated/accepted name of genera/species of cyanobacteria.

Composite materials are progressively being employed in the aerospace, automotive, aeronautics, and marine sectors because of their high strength-to-weight ratio. Traditional machining methods have trouble machining composite materials. However, laser cutting provides an alternative quality machining method that can be accomplished by regulating various process variables. A commonly used thermally dependent non-contact advanced machining technique is laser cutting. The efficiency of the laser cutting method is the subject of extensive study. Analytical approaches based on Regression analysis, and Response surface methodology (RSM) are all standard techniques for solving optimization issues in laser cutting utilizing the Taguchi method. The main theories and practices used in the Taguchi method are explored in this article, as well as a summary of the Taguchi method. The paper discusses research study based on the implementation of the Taguchi method for laser cutting process optimization after examining the parameters as well as performance requirements of the laser cutting process and further concluded that most of the performance characteristics studied (kerf taper, and deviation) as well as surface quality was found to be related (surface roughness). In addition, the Taguchi method has only been utilized to increase metallurgical properties (HAZ, Burr inclusion) and production efficiency (MRR). Taguchi method, being a model-free optimization technique, restricts further level interpolation or extrapolation. It was also reported that to address this shortcoming of the Taguchi method, it was combined with response surface methodology to get optimal results. This paper offers a review of the literature's findings and addresses the problems that need to be discussed.

Biosynthesis is progressing owing to economical synthesis and the availability of organisms (good source of metabolites) which significantly complex and cap the metallic ions to produce stable nanomaterials.

Owing to enormous increase in the automobile population, traditional petroleum fuels for internal combustion engines will be usable only for a few years. Moreover, by releasing toxic emissions into the atmosphere at higher levels these fuels create severe environmental problems. In general, Carbon-monoxide (CO), Unburnt hydrocarbons (UHC), and smoke are emissions emitted by engines. The pollution of the environment can be controlled by replacing petroleum fuel with the use of alternative fuels like acetylene gas, hydrogen, CNG, LPG etc. In this current research, an experimental investigation was carried out in Compression Ignition engine using acetylene fuel, further enhancing the performance and emission properties by using diethyl ether (DEE) and ethanol as oxygenated fuel. In view of the performance and outflow (emission) parameters optimizing valve of acetylene gas as 12 lpm with oxygenated fuels, the performance and outflow characteristics were improved. The findings show an enhancement in brake thermal-efficiency of up to 3 to 4%, a decrease in exhaust temperature and emissions like CO, UHC and smoke of up to 40%, 20%–30% and 10%–35% respectively, there is decrease in fuel consumption of 10%–30%. It was found that ethanol is better than diethyl ether and diesel fuels when used as an oxygenated fuel with acetylene gas. In view of the performance and emission parameters, the best oxygenated fuel is ethanol and the optimize blend for diesel engine is E15+A12.

For the general public, healthcare facilities are always a safe and secure place for treatment. Generally, healthcare institutions are equipped to deal with exterior interruptions, but circumstances brought on by internal risks are more serious and frequently require an emergency evacuation of the facility. An incident happened at the radiodiagnostic setup of a tertiary care institute in North India. This fire incident created panic among staff and patients. At the place of casualty, there were around 150 persons, including staff, patients, and their attendants. Immediately after the confirmation of the fire incident, the fire department and security department took action in the form of fire control and smoke evacuation. Though six fire handling staff required minor emergency services for asphyxia due to smoke inhalation and were cured by oxygen support only, none of the patients was affected due to timely smoke evacuation. Most often, smoke management techniques implemented are compartmentation, pressurization, dilution, ventilation, buoyancy, and airflow. So, we concluded that the step of timely smoke evacuation and preventing the spread of smoke by various methods help to reduce fatality due to smoke. The training programs and mock drills give stakeholders the needed knowledge, skills, and practice they need to safeguard patients and employees.

Operations management is a key aspect in any manufacturing business. Optimising the management of manufacturing operations allows improvement of the productivity and efficiency of industrial activities. To achieve this, reducing waste from manufacturing processes and, therefore, implementing lean-manufacturing principles, is key. This article presents a case study to reduce waste in changeover processes at a ready-meal manufacturer based in South Yorkshire, UK. We identified a large number of activities as part of the changeover process. We applied the Single Minute Exchange of Dies (SMED) methodology to reduce and, whenever possible, eliminate changeover, and line hopping to further optimise changeover. After implementing improvement measures, changeover time was reduced by nearly 30%, OEE was increased to over 70%, and labour costs were reduced by 10%. This shows how lean principles can aid in implementing more effective and economically sustainable manufacturing operations.

On-going research is aimed at commercializing low temperature fuel cell technology systems as zero emission alternatives for automotive applications in order to reduce greenhouse gas emissions and air pollution. These systems use polymer electrolyte fuel cells (PEFCs) to generate electricity via an electrochemical process using hydrogen and ambient air (oxygen) to produce water. Advantages of PEFCs include quick start-up time, low operating temperature, low weight, high efficiency, and relatively simple design. An important area of current research is the identification of factors which affect fuel cell performance degradation during operation and ultimately, its durability. A technique that has yielded new insights in the investigation and identification of failure modes in fuel cells is lab-based X-ray computed tomography (XCT), which is most advantageous due to its on-demand availability. The Fuel Cell Research Laboratory (FCReL) at Simon Fraser University currently operates Canada’s only facility for multi-length scale XCT, comprising of two state-of-the-art laboratory-based XCT scanners from Carl Zeiss X-ray Microscopy (Zeiss Xradia 520 Versa and 810 Ultra) with complementary resolution and field of view capabilities. This unique combination offers unprecedented access to investigations at multi length scales; with an ability to probe fuel cell components at the micro as well as the nano scale. Figure 1 illustrates the fuel cell holder and its orientation with respect to the X-ray beam as well as an exploded view of the miniature fuel cell design. An overview of recent fuel cell degradation investigations at FCReL using the XCT technique will be shown. The XCT based workflow facilitates determination and quantification of material structure and properties changes resulting from degradation stresses associated with operational parameters such as temperature, relative humidity, and voltage. The non-destructive nature of lab-based XCT visualization coupled with the ability to scan the same fuel cell multiple times without inducing damage [1] has enabled detailed studies of fuel cell degradation evolution in four dimensions (3D space, 1D time) [2 - 4]. The new knowledge gained from this procedure has led to root cause identification with respect to membrane and catalyst layer crack initiation and propagation [5 - 7], sealing issues [8,9], and subsequent mitigation toward enhanced fuel cell durability. Acknowledgement This research was supported by the Natural Sciences and Engineering Research Council of Canada, Canada Foundation for Innovation, British Columbia Knowledge Development Fund, Western Economic Diversification Canada, Canada Research Chairs, and Ballard Power Systems. References: [1] R.T. White, M. Najm, M. Dutta, F.P. Orfino, E. Kjeang, J. Electrochem. Soc. 163 (2016) F1206-F1208 [2] R.T. White, A. Wu, M. Najm, F.P. Orfino, M. Dutta, E. Kjeang, J. Power Sources 350 (2017) 94-102 [3] R. T. White, S. H. Eberhardt, Y. Singh, T. Haddow, M. Dutta, F. P. Orfino, E. Kjeang, Scientific Reports, (2019) 9:1843 [4] R. T. White, D. Ramani, S. H. Eberhardt, M. Najm, F. P. Orfino, M. Dutta, and E. Kjeang, J. Electrochem Soc, 166 (2019) F914-F925 [5] Y. Singh, R. T. White, M. Najm, T. Haddow, V. Pan, F. P. Orfino, M. Dutta, and E. Kjeang, J. Power Sources, 412 (2019) 224 [6] D. Ramani, Y. Singh, R. T. White, M. Wegener, F. P. Orfino, M. Dutta, and E. Kjeang, International Journal of Hydrogen Energy, 45 (2020) 10089-10103 [7] D. Ramani, Y. Singh, R. T. White, T. Haddow, M. Wegener, F. P. Orfino, L. Ghassemzadeh, M. Dutta, and E. Kjeang, Electrochimica Acta 380 (2021) 138194 [8] Y. Chen, Y. Singh, D. Ramani, F. P. Orfino, M. Dutta, and E. Kjeang, J. Power Sources, 520 (2022) 230674 [9] Y. Chen, Y. Singh, D. Ramani, F. P. Orfino, M. Dutta, and E. Kjeang, J. Power Sources, 520 (2022) 230673 [10] J. Stoll, F. P. Orfino, M. Dutta, and E. Kjeang, J. Electrochem Soc, (2021) 168 024516 Figure 1

Natural-fiber-reinforced composites are progressively attracting interest in the aerospace, automotive, aeronautics, and marine sectors due to their good strength-to-weight ratios, long lifetimes and cost-effectiveness. Traditional machining methods have trouble machining such composite materials. However, abrasive water jet machining (AWJM) provides an alternative quality machining method that can be accomplished by regulating various process variables. The efficiency of the AWJM method has been the subject of extensive study, due to its negligible heat-affected zone. This review attempts to focus on an exploration of the thermal and mechanical properties and the AWJM efficiency of various coir-fiber-based composites in relation to various parameters and to determine the best AWJM operating conditions. There are numerous process variables that influence AWJM machined surface quality. However, the standoff distance, hydraulic pressure, abrasive mass flow rate, nozzle diameter, and transverse speed are all important factors to consider. Kerf taper, kerf width, and surface roughness are considered key response factors.

This work is a two-part article series on chemo-mechanical membrane degradation in fuel cells, wherein the present work in Part 1 investigates edge failure and Part 2 investigates failure within the active area of an edge-protected cell. Membrane electrode assembly (MEA) edges are sensitive regions that can cause premature failure. Here, two different MEA frame designs are implemented to study their robustness during a combined chemical/mechanical membrane degradation accelerated stress test. 4D in situ visualization by periodic, identical-location X-ray computed tomography is performed to understand and thus mitigate the design issues responsible for edge failures. Interfacial interaction of adhesive-containing polyimide gasket and MEA and non-uniform load distribution along MEA edges are identified as the two key contributors to premature edge failures, which introduce significant cell voltage decay due to permanent membrane deformation. Edge failure mitigation is demonstrated by using a non-adhesive sub-gasket along with increased gasket coverage area, which leads to: (i) delayed onset of edge failure; (ii) five times reduction in edge crack size; (iii) elimination of membrane tearing; and (iv) minimal impact of edge failures on cell performance, thus enabling a robust MEA edge wherein the performance-impacting failure is shifted to the more important active area regions.

This work is a two-part article series on chemo-mechanical membrane degradation in fuel cells, wherein Part 1 investigated edge failure and the present work in Part 2 investigates failure within the active area of an edge-protected cell. X-ray computed tomography based 4D visualization with three spatial dimensions plus one time dimension is applied to capture the progress of membrane degradation under chemo-mechanical accelerated stress testing. Buckling driven membrane cracks are found to be the predominant failure mechanism, occurring exclusively under the uncompressed flow field region. In situ electrochemical diagnostics show significant gas crossover and dramatic open-circuit cell voltage loss accompanying membrane crack formation. The observed root cause of membrane buckling is facilitated by pre-existing cracks and surface pores in the catalyst and microporous layers, which enable hygral expansion and locally amplified compressive-tensile stress cycles in the membrane. Moreover, permanent membrane creep into gas diffusion layer pores is identified exclusively under the compressed land region, which is driven by locally elevated compressive stress in the membrane. Chemical stress is inferred to be a contributing, accelerating factor in this degradation process as a uniform, global effect rather than a locally amplified cause of failure.

Decomposition influences carbon and nutrient cycling from crop residues. The nylon-mesh-bag technique was implied to study the decomposition and N-release dynamics from different crop residues under field conditions. The four types of residues were: maize (lower than 50% below the cob), wheat (lower than 25% of wheat stubbles), a whole mung bean residue, and a mixture of wheat + mung bean residue (1:1 ratio) put on the soil surface and in below the sub-surface. Decomposition and N release from both at-surface- and below-surface-placed residues were accurately described by a single-pool first-order exponential decay function as a function of thermal time (based on the accumulative daily mean temperature). The simple first-order exponential model met the criteria of goodness of fit. Throughout the decomposition cycle (one thermal year), the rate of decomposition as measured by a decrease in residue mass and the release of total N were statistically higher from the sub-surface compared to the surface-placed residue, irrespective of the residue type. At the end of the 150-day decomposition cycle, the release of total N was highest in mung bean (32.0 kg N ha−1), followed by maize (31.5 kg N ha−1) > wheat + mung bean (16.1 kg N ha−1), and the minimum (6.54 kg N ha−1) in wheat residue. Crop residues with a wider C/N ratio such as maize and wheat, when applied on the soil surface in conservation agriculture, caused the decomposition to occur at slower rates, thereby providing long-term beneficial effects on the soil thermal regime, soil moisture conservation, and C sequestration in North-West India.

To study the solar rotational oscillation on daily averaged time series of solar activity proxies: sunspot number (SSN), modified coronal index (MCI), solar flare index (FI), and cosmic ray intensity (CRI) are subjected to Lomb/Scargle periodogram, and continuous wavelet transform. For this purpose, we have used data of all the considered parameters from 2012 to 2015, which covers the maximum phase including the polarity reversal period of the solar cycle 24. Both spectral analysis techniques are carried out to study the behavior of 27-days on the time scale of the synodic period and to follow their evolution throughout the epoch. Further, we have used R package RobPer (least square regression) techniques and obtained a significant true period ∼27 days is present in this study. It is noted that the ∼27-day period of solar activity parameters and cosmic rays is much prominent during the examined period.

Repetitive hygrothermal fluctuations cause mechanical membrane degradation in fuel cells, which requires mitigation for longevity. Part 1 of this work demonstrated that gas diffusion layers (GDLs) with low surface roughness can improve lifetime by reducing harmful buckling phenomena during wet/dry cycling. As a second novel mitigation approach in the present work (Part 2), the catalyst coated membrane (CCM) is bonded with the GDLs to eliminate relative motion and further curb mechanical degradation. A custom miniaturized fuel cell fixture is used within a laboratory-based X-ray computed tomography system to visualize the membrane degradation process during wet/dry cycling. Compared to a non-bonded baseline cell, membrane buckling is shown to be completely arrested with bonding and lead to a two-fold increase in lifetime. Membrane crack development is still observed as the key failure mode, preceded by cathode catalyst layer fracture. However, the root causes are related to bonding irregularities and compressive impingement of GDL fibers rather than membrane buckling. Complementary finite element simulations of a representative fuel cell assembly are carried out to fundamentally establish the favorable effect of improved CCM-GDL adhesion on membrane durability. Overall, the improved adhesion of the bonded cell provided substantial mitigation against fatigue-driven mechanical membrane degradation and failure.

Hygrothermal variations that arise during dynamic fuel cell operation are known to generate mechanical stresses in the ionomer membrane. Previous research has indicated that membrane electrode assembly (MEA) interaction effects may influence membrane degradation under such loads. The present objective is therefore to evaluate novel MEA design strategies for mitigating mechanical membrane degradation in fuel cells. In this case (Part 1), a gas diffusion layer (GDL) with low surface roughness is applied to suppress buckling-driven membrane failures. Laboratory-based X-ray computed tomography is used in a customized, time-resolved workflow for non-invasive four-dimensional characterization of membrane damage evolution during accelerated stress testing. Membrane crack development is the key failure mode preceded by fracture of the cathode catalyst layer. In comparison to high surface roughness GDL, the severity of membrane buckling is substantially reduced by adoption of the smoother GDL, contributing 2x greater lifetime. Accompanying finite element simulations of the unit fuel cell assembly show plastic strain accumulation in the buckled membrane and identified a critical range of GDL void sizes that influence membrane buckling. Overall, the improvement in GDL surface demonstrates substantial mitigation effect against fatigue-driven mechanical membrane degradation and failure, which is also corroborated by the numerical simulation results.