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Carbon-Fibre-Reinforced Polymers (CFRPs) have seen a steady rise in modern industrial applications due to their high strength-to-weight ratio and corrosion resistance. However, their potential is being hindered by delamination which is induced on them during machining operations. This has led to the adoption of new and innovative techniques like cryogenic-assisted machining which could potentially help reduce delamination. This study is aimed at investigating the effect of cryogenic conditions on achieving better hole quality with reduced delamination. In this paper, the numerical analysis of the drilling of CFRP composites is presented. Drilling tests were performed experimentally for validation purposes. The effects of cooling conditions and their subsequent effect on the thrust force and delamination were evaluated using ABAQUS/CAE. The numerical models and experimental results both demonstrated a significant reduction in the delamination factor in CFRP under cryogenic drilling conditions.

The ever-increasing demand for materials to have superior properties and satisfy functions in the field of soft robotics and beyond has resulted in the advent of the new field of four-dimensional (4D) printing. The ability of these materials to respond to various stimuli inspires novel applications and opens several research possibilities. In this work, we report on the 4D printing of one such Shape Memory Polymer (SMP) tBA-co-DEGDA (tert-Butyl Acrylate with diethylene glycol diacrylate). The novelty lies in establishing the relationship between the various characteristic properties (tensile stress, surface roughness, recovery time, strain fixity, and glass transition temperature) concerning the fact that the print parameters of the laser pulse frequency and print speed are governed in the micro-stereolithography (Micro SLA) method. It is found that the sample printed with a speed of 90 mm/s and 110 pulses/s possessed the best batch of properties, with shape fixity percentages of about 86.3% and recovery times as low as 6.95 s. The samples built using the optimal parameters are further subjected to the addition of graphene nanoparticles, which further enhances all the mechanical and surface properties. It has been observed that the addition of 0.3 wt.% of graphene nanoparticles provides the best results.

Additive manufacturing (AM) is replacing conventional manufacturing techniques due to its ability to manufacture complex structures with near-net shape and reduced material wastage. However, the poor surface integrity of the AM parts deteriorates the service life of the components. The AM parts should be subjected to post-processing treatment for improving surface integrity and fatigue life. In this research, maraging steel is printed using direct metal laser sintering (DMLS) process and the influence of grinding on the fatigue life of this additively manufactured material was investigated. For this purpose, the grinding experiments were performed under two different grinding environments such as dry and cryogenic conditions using a cubic boron nitride (CBN) grinding wheel. The results revealed that surface roughness could be reduced by about 87% under cryogenic condition over dry grinding. The fatigue tests carried out on the additive manufactured materials exposed a substantial increase of about 170% in their fatigue life when subjected to cryogenic grinding.

A Corrugated doubly curved sea shell form Concrete Structure of 70 mm thickness is functioning for the past 21 years, with good performance in an institutional building entrance hall of size 30m x 30m. The shell having only boundary beam; sloping to one diagonal corner at + 5 m level, the adjacent two opposite diagonal corners at +7 m level and the peak corner is at + 9 m level, supported by columns and footings are resting on rock. The designer has not taken care for thermal resistance performance and not checked for earth quake, and there was no maintenance except periodical cement based whitewash. But, it has performed well in an earthquake of Richter magnitude 4.0 and performing well for the climatic temperature variations ranging from 19◦C to 44◦C during the 21 years of life span. Vertical micro cracks were noticed in the boundary beams. Roof Shell is fixed with the boundary beams. The roof top surface is fixed with weathering ceramic tiles of size 25 mm x 25 mm bonded using tile bond branded chemical adhesive, has opened bonding in a period of five years in the higher deformation area. Hence, the observation was started by performance based health monitoring. Suitable smart materials were applied for surface skin coat to take care of the positive and negative stress-strains and deformations due to temperature variations. The static and dynamic stability against overturning, sliding and gravity forces is ensured adequate. The integral action of the system and the Elastic and Inelastic ductile behaviour of the shell are observed to be higher.

Despite the remarkable evolutionary success of insects at colonizing every conceivable terrestrial and aquatic habitat, only five Halobates (Heteroptera: Gerridae) species (~0.0001% of all known insect species) have succeeded at colonizing the open ocean – the largest biome on Earth. This remarkable evolutionary achievement likely required unique adaptations for them to survive and thrive in the challenging oceanic environment. For the first time, we explore the morphology and behavior of an open-ocean Halobates germanus and a related coastal species H. hayanus to understand mechanisms of these adaptations. We provide direct experimental evidence based on high-speed videos which reveal that Halobates exploit their specialized and self-groomed body hair to achieve extreme water repellence, which facilitates rapid skating and plastron respiration under water. Moreover, the grooming behavior and presence of cuticular wax aids in the maintenance of superhydrophobicity. Further, reductions of their body mass and size enable them to achieve impressive accelerations (~400 ms−2) and reaction times (~12 ms) to escape approaching predators or environmental threats and are crucial to their survival under harsh marine conditions. These findings might also inspire rational strategies for developing liquid-repellent surfaces for drag reduction, water desalination, and preventing bio-fouling.

The purpose of this study was to see how silane treatment affected the tensile and impact strength of composites constructed from jute/kenaf/glass fibers with a nano-graphene filler and to investigate the impact of major treatment factors, such as silane concentration, immersion duration, and nano-filler, on composite characteristics. To conduct systematic trials and improve these variables, the Response Surface Methodology (RSM) with central composite designs was used. To precisely forecast the tensile and impact strength of the nano-composite following silane treatment, quadratic models were built. By changing the silane concentration, immersion period, and nano-filler, they discovered ideal conditions for increasing tensile strength. The best ranges for silane concentration and immersion duration were discovered to be 15 wt. % and 30 min, respectively. Given the conditions, the composite impact strength increased by 51% and its tensile strength improved by 22% as compared to the values achieved from RSM optimization. These results highlight the practical importance of silane treatment, especially in improving tensile and impact strength and strengthening the interfacial adhesive characteristics of organic fibers and polymer matrices. [ABSTRACT FROM AUTHOR]

Facing growth pressures, firms attempt to target the large low-income consumer segment present in emerging markets. This multi-method study develops research insights regarding consumer-, retailer-, firm-, category- and country-level factors that enhance the acceptability, awareness, availability, and affordability of products that facilitate the low-income consumer adoption of and firms' introduction of new products for low-income consumers. Study 1 uses a qualitative grounded-theory approach by interviewing company managers and low-income consumers in India and Chile. Study 2, empirically tests an integrated multi-level model of several category factors identified in Study 1, combined with country-level factors drawn from the literature, using a unique 12-year longitudinal panel dataset of new product introductions in 27 emerging market countries from Africa, Asia, Eastern Europe, and South America. The research identifies consumer aspirations, region-based versioning, visible packaging and the product demonstrations as critical motivating factors for adoption of products by low income consumers. Consumers' knowledge of the product category, the concentration of branded products, availability of global brands, and the presence of traditional retail stores motivate firms to launch products for low income consumers in emerging markets., Author(s): S. Arunachalam [sup.1] , S. Cem Bahadir [sup.2] , Sundar G. Bharadwaj [sup.1] [sup.3] , Rodrigo Guesalaga [sup.4] Author Affiliations: (1) grid.462395.f, 0000 0004 0496 9265, Indian School of [...]

As emerging market international marketing alliances (E-IMAs) are becoming popular as instruments of growth for firms from the developed markets that are attempting to expand into emerging markets, there is a growing need to understand how these E-IMAs are formed, operate, and even get dissolved in the emerging markets. Extant theories on IMAs, although limited, have primarily focused on alliances that are formed and operate in developing markets. However, as the institutional context of emerging markets differs significantly from that of developing markets, these existing theories are not sufficient to explain and predict phenomena related to E-IMAs. Therefore, using data from in-depth interviews with senior executives from 106 companies involved in marketing alliances, this study develops a new theoretical model based on the awareness-motivation-capability framework that can explain and predict phenomena related to E-IMAs. Related propositions are presented for both researchers and practitioners who are interested in studying or developing E-IMAs., Author(s): Kiran Pedada [sup.1] , S. Arunachalam [sup.2] , Mayukh Dass [sup.3] Author Affiliations: (1) grid.462395.f, 0000 0004 0496 9265, Indian School of Business, , Sector 81, Knowledge City, 160062, [...]

The essential objective of this work was to investigate the effect of silane treatment on the tensile and impact strength of composites made of jute/kenaf/glass fibers with the TiO2 nano-filler. This study also sought to optimize the factors connected with this treatment method. To develop and evaluate trials, the researchers used Response Surface Methodology (RSM) with central composite designs, emphasizing the optimization of silane concentration, immersion time, and nano-filler content. The researchers were able to effectively create quadratic models to forecast the tensile and impact strengths of the nano-composite throughout the silane treatment procedure. The adjustment of silane concentration, immersion duration, and nano-filler content discovered the best conditions for obtaining maximum tensile strength. The optimal values for silane concentration and immersion time have been identified to be 15 wt. % and 30 min, respectively. Considering these conditions, the composite's tensile strength increased by 32.13% and its impact strength improved by 8.34% above the lowest values achieved from RSM optimization. The results demonstrate the practical value of silane treatment, notably in boosting tensile and impact strengths while enhancing interfacial adhesive among natural fibers and polymer matrices. [ABSTRACT FROM AUTHOR]