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To meet the global requirements of the industry, there is a need for innovative light weight, low cost, eco-friendly, high quality engineering materials with superior performance at a wide range of temperatures. Aluminum Matrix Composites (AMCs) are lightweight materials with isotropic properties, a suitable choice for modern industry. Low-cost aluminium alloys reinforced with minerals have found a special place in the automotive industry for the manufacture of automobile parts. Rutile particles improve the mechanical properties of the aluminum matrix, making it attractive for structural applications as well as providing greater wear resistance to the composite during sliding. In the present studies, a rutile mineral reinforced LM27 aluminum alloy composite was developed through a stir casting route with 6, 9 and 12 wt.% reinforcements. To study the effect of particle size on the mechanical and tribological properties of composite samples reinforced with fine-sized (50–75 µm) and coarse-sized (106–125 µm) rutile particles were prepared. From the results of the experiment, it was found that the hardness, compressive strength and wear resistance increase with increasing rutile wt.% addition.

DOI: https://doi.org/10.3390/lubricants10100251

A novel PCL/HA/TiO2 hybrid coating on ZM21 Mg alloy substrate has been investigated for corrosion resistance, biocompatibility and mechanical integrity loss in terms of bending, compressive and tensile strength in physiological media. The electrochemical measurement and in-vitro degradation study in SBF after 28 days showed that the PCL/HA/TiO2 hybrid coating reduced H2 evolution rate, weight loss, and corrosion rate by 64, 116 and 118 times respectively, as compared to uncoated ZM21 samples. The in-vitro cellular viability of L929 fibroblast cells on PCL/HA/TiO2 hybrid coating was found 50.47% higher with respect to control group, whereas bacterial viability was supressed by 57.15 and 62.35% against gram-positive Staphylococcus aureus and gram-negative Escherichia coli bacterial models. The comprehensive assessment indicates PCL/HA/TiO2 hybrid coating as a suitable candidate to delay early degradation and mechanical integrity loss of Mg-based alloys for devising biodegradable orthopaedic implant.

https://doi.org/10.1016/j.jma.2021.10.004

Mg and its alloys evince strong candidature for biodegradable bone implants, cardiovascular stents, and wound closing devices. However, their rapid degradation rate causes premature implant failure, constraining clinical applications. Bio-functional surface coatings have emerged as the most competent strategy to fulfill the diverse clinical requirements, besides yielding effective corrosion resistance. This article reviews the progress of biodegradable and advanced surface coatings on Mg alloys investigated in recent years, aiming to build up a comprehensive knowledge framework of coating techniques, processing parameters, performance measures in terms of corrosion resistance, adhesion strength, and biocompatibility. Recently developed conversion and deposition type surface coatings are thoroughly discussed by reporting their essential therapeutic responses like osteogenesis, angiogenesis, cytocompatibility, hemocompatibility, anti-bacterial, and controlled drug release towards in-vitro and in-vivo study models. The challenges associated with metallic, ceramic and polymeric coatings along with merits and demerits of various coatings have been illustrated.

https://doi.org/10.1016/j.bioactmat.2022.05.009

Let R be a finite commutative chain ring with unity and be a unit in R. In this paper, all non-trivial linear complementary pair (LCP) of λ-constacyclic codes of arbitrary length over R have been completely determined. An expression for the total number of non-trivial LCP of λ-constacyclic codes of length n over R has also been derived in terms of the maximum number of factors of xn λ into monic, pairwise coprime polynomials of degree greater than or equal to 1 over R. Further, using the algebraic structure of λ-constacyclic codes over finite chain rings of nilpotency index 2 as an alternative approach, the complete characterization of non-trivial LCP of λ-constacyclic codes is obtained for such rings. As an illustration of our results, a few examples of non-trivial LCP of constacyclic codes over the rings Z8, Z4 and the Galois ring GR(4, 3) have been given.

DOI: 10.1007/s12190-022-01816-w

Abandoned ash pond beds have been considered for their reclamation through the construction of lightweight structures. Under static conditions, an ash pond bed can sustain these structures but its stability must be ascertained under seismic conditions. This paper presents the results of geotechnical characterization and dynamic properties of pond ash samples that were collected from three different locations ranging from the inflow point to the outflow point of the ash pond of the Ropar thermal power plant (India). Strain-controlled cyclic triaxial tests were conducted on collected samples, considering the effect of various parameters, such as shear-strain amplitude, confining pressure, frequency, and density. The shear modulus of the coarser pond ash sample near the inflow was observed to be greater than that of the finer pond ash near the outflow. The shear-strain amplitude and frequency of cyclic loading increases with a decrease in the shear modulus. The damping ratio is greater in the case of finer ash. Moreover, damping ratio increases with an increase in strain amplitude and frequency of loading. The dynamic behavior of the pond ash sample was also compared with that of sand. The area near the inflow of the ash pond, where there is coarser ash was found to be more suitable for reclamation of the ash pond bed under seismic conditions. Dynamic properties of spatially varied pond ash within an ash pond

• J Singh and S.K Singh (2022) Dynamic Properties of Spatially-Varied Pond Ash within a Coal Ash Pond, International Journal of Geomechanics, Vol 22, No.3, American Society of Civil Engineers (ASCE), DOI: 10.1061/(ASCE)GM.1943-5622.0002255, SCI, Web of Science Impact Factor: 3.819, ISSN 1532-3641.
• J Singh, S.K Singh and M A Alam (2019) A study on the geotechnical characterization and water retention characteristic curve of pond ash, Water Science Technology, Vol 80, No. 5, pp 929-938. SCI Expanded, IWA publishing, https://doi.org/10.2166/wst.2019.334
• A. Malik and S. K. Singh (2023) Dynamic Behaviour of Pond Ash Mixed with Coir and Crumb Rubber, Journal of Renewable Materials, Tech Science Press, Vo. 11, No.3, DOI: 10.32604/jrm.2022.023084

A flexible poly(vinylidene difluoride) (PVDF) composite film embedding LiNbO3 ceramics decorated with silver nanoparticles (Ag NPs) has been synthesized using the solvent casting method. The polar β-phase, Ag NPs, and LiNbO3 phases were confirmed in the composite film using various characterization methods. The composite film showed promising degradation of cationic and anionic dyes using piezocatalysis under ultrasonication. Moreover, this composite film also effectively degraded two model pharmaceutical pollutants named tetracycline and ciprofloxacin using piezocatalysis under ultrasonication. In addition to this, this composite film piezocatalytically removed more than 99.999% of Escherichia coli and 96.65% of Staphylococcus aureus bacteria within 180 min of sonication. The piezocatalytic performance of the PVDF composite film embedding Ag- loaded LiNbO3 in all three applications was superior to that obtained in the case of the PVDF film embedding LiNbO3 and the bare PVDF film. This demonstrates the pronounced effect of Ag NPs in the increase of piezocatalytic activity in the composite film.

https://doi.org/10.1021/acsami.1c01314

This study has been carried out with the objective of mapping/ verification of allotted sand mining areas, estimation of extracted sand quantity, identification of unauthorized mining activities, and verification of environmental clearance conditions (as per MoEF, GOI) for the Gumthala South Block, Gumthala North Block, Nagli Block, and Malikpur Khadar Block. A field visit comprising experts from Punjab Engineering College and officials of the Principal Accountant General (Audit, Haryana) was carried out on 18 June 2019. During the visit, observations regarding sand mining practices, area verification, and environmental issue were made for Gumthala South Block, Gumthala North Block, Nagli Block, and Malikpur Khadar Block. Apart from Malikpur Khadar, all other blocks are sand mining blocks. Malikpur Khadar is a Cobble/Boulder mining block.

Report submitted to CAG

Groundwater is a vital resource of potable water in India as almost all industries require water due to one or other reasons. It may get polluted by industrial waste, leachate from dumping yards, rampage, and uncontrolled use of pesticides. The physicochemical properties of water give a general indication of the interference capability of water with the normal biological process of the environment. Most heavy metals are present in trace amounts in the groundwater and useful for the human body. However, if they exceed the permissible limits these may cause health hazards. In this study, an attempt has been made to assess, analyze, and mapping groundwater quality using the Geographical information system (GIS). In this study, five heavy metals (aluminium, arsenic, cadmium, iron, selenium) and six physiochemical parameters (pH, total hardness, alkalinity, chloride, fluoride) have been used to achieve the objectives. Gurdaspur (Punjab, India) was selected for the study as it ranks fourth in the cancer cases after Amritsar, Ludhiana, and Bathinda as per the government reports. Field visits were made to collect samples and preservation techniques were followed according to standard methods (APHA 2005). Single-digit indices like the water quality index (WQI), heavy metal pollution index (HPI), metal index (MI) were used to classify the quality of water. Volumetric analysis and ion chromatography tests were carried out on the grab samples of 25 locations, which were collected in Dec’2019. Arsenic was found to exceed the permissible value in nearly 80% of samples. It has been observed that MI values exceeded the critical value of 1, indicating the pollution caused by the individual metal was more as compared to the pollution caused by all metals together. IDW interpolation technique was applied to all indices using GIS software to determine spatial distribution. Overall, WQI was found to be satisfactory, with only 20% of the sampling stations exceeding the acceptance value. The average value of the heavy metal pollution index (HPI) was 80% of the sampling stations. Further, an attempt has been made to determine the cancer risk of the inhabitants in the study area. The health risk index (HRI) was determined by chronic daily intake and hazard quotient as per USEPA. The hazard quotient (HQ) value of heavy metals was found to be greater than unity in all the selected areas, indicating that heavy metals pose a health threat in this region. It has been observed that the hazard quotient value is higher for children than adults, implying more vulnerability of children to a potential health hazard. Actual total cancer risk was found to be 33.65×10-4, which means ~34 persons in 10,000 people have the possibility of cancer. A hypothesis was that reduced the theoretical risk to 31.65×10-4 which was found to be comparable to the actual cancer risk. It has been observed that the cancer risk for children and adults were in the “high risk” category. The higher values of arsenic can be attributed to higher cancer risk and health quotient value. Both children and adults were found to be risk-prone to both carcinogen and noncarcinogen health effects, with children on the higher side.

DOI: https://doi.org/10.1007/s12594-022-2097-8

Stubble burning during October and November, results in the extensive formation of smoke cloud over the Punjab region, and maybe one of the main reasons behind the increase in air pollution levels in these areas. The manual detection and estimation are tedious, lengthy and unpractical, so several researchers have been using remote sensing and GIS technique to estimate stubble burn areas and forest fires. Thus, in the present study, an attempt has been made to detect and estimate the stubble burn area. Landsat 8 OLI images are used to detect the stubble burn area for the year 2014-18 for Patiala and Ludhiana, which are major rice producing districts of Punjab. Normalize Burn Ratio (NBR) index have been used to determine the burned area in an image using a statistical threshold technique (2σ approach). The results have been validated using available as well as collected Ground Control Points (GCPs) and accuracy assessment has been conducted by generating an error matrix. It has been estimated that the stubble burn area was reduced by 32% and 40% during the study period for Patiala and Ludhiana regions, respectively. The monthly variation for various pollutants (RSPM, NOx, and SO2) during the study period has also been studied and analyzed. The distinct increase in pollutant levels has been observed during each stubble burning period. The results also indicate that the amount of emitted RSPM and NOx was higher than the emitted SO2 during stubble burning. The wind rose diagrams have also been plotted.

DOI: https://doi.org/10.1016/j.heliyon.2019.e03095

It is essential to assess the gradual slope deformations which can be used to interpret the temporal changes in any mountainous terrain provided the magnitude and orientation of the downward displacements are known. In this study, the slope surface displacements of two vulnerable and high-priority slopes at 12.55 km and 13.85 km from a reference point called Zero bridge along the Tehri-Koteshwar transportation route in the vicinity of Koteshwar area, Uttarakhand, India, were analysed. The study was carried out using orthorectified linear imaging self-scanning (LISS IV) optical remote sensing data from the year 2012–2017 for estimating the surface displacements based on the pixel shift with the help of COSI-CORR (co-registration of optically sensed images and correlation) tool in ENVI (Exelis visual information solutions) platform. The slopes considered in this study were mapped on the field and were demarcated on the high-resolution optical imageries, i.e. LISS IV mx (5.8 m resolution). Initially, the various optical images (slave images) ranging from the year 2012–2017 were co-registered using a master image (geo-referenced). These co-registered imageries were run for correlation using five sets of image pair (i.e. the year 2012–2013, 2013–2014, 2014–2015, 2015–2016 and 2016–2017) which reflected the pixel shifts in the images with respect to the each other. The pixel shifts in all the image pairs were modelled using ERDAS imagine software to calculate the slope surface displacements, and a similar model was run for all the image pairs. This resulted in various values of slope surface displacements over the time period of five years. The resultant displacement rasters were then analysed for displacement vector fields which indicated the direction (bearing) of material movements. The average pixel shift trends for various image pairs have indicated that the slope surface displacements increased between the year 2012–2015 whereas, after 2015, the correlation indicated a decrease in the surface displacements at the study sites. This study has highlighted the use of optical remote sensing data in analyzing the gradual slope movements and their orientation. Such a study can be utilized to estimate slope deformation annually. This may help researchers/stakeholders to understand the planning/managing mitigation measures on the required locations of vulnerable slopes.

DOI: https://doi.org/10.1007/978-3-030-76116-5_5