Recent advancements in nano-lubrication strategies for machining processes considering their health and environmental impacts

Industries have been seeking an efficient lubrication system that meets the requirement of sustainability without compromising manufacturing efficiency or final part quality. Conventional cutting fluids have been recognized as hazardous to the environment, health and economy of industries. The nano lubrication strategy has emerged as a sustainable and power-efficient lubrication system with encouraging performance in machining processes. This paper encapsulates an overview of the impact regarding usage of nanofluid as a cutting fluid in different machining processes. The recent innovations in the past decade, altered nano lubrication systems have been briefly summarized. A state of art review commences with a short synopsis of the historic perspective followed by a summary of the impact of nanofluid on different machining processes. The discussion section has been bifurcated according to the characterization of machining performance metrics. The environmental and health issues that emerged with the use of nanofluid are then discoursed thoroughly. Finally, the major findings are summarized and the future scope of research is identified. It can be quantified that the implementation of a nano lubrication system can significantly improve the heat transfer characteristic of base fluid which ultimately leads to the functionally tremendous product. However, there are major unknowns related to the health and environmental impact of nanoparticles

Response of Hirayama disease to surgical intervention: case report

Hirayama disease also known as monomelic amyotrophy, primarily involves distal upper limb extremities.It differs from the known types of motor neuron diseases because of its nonprogressive behavior and pathologic findings of focal ischemic changes in the anterior horn of the lower cervical cord. We present a young male with Hirayama disease who had a left upper extremity involvement which was progressive in nature. He didn’t respond with initial treatment of cervical collar. Consequently surgical intervention improves muscle weakness and decrease the neurological deficit. 

Mechanism of action of the tetraflex accommodative intraocular lens

PURPOSE:To investigate the mechanism of action of the Tetraflex (Lenstec Kellen KH-3500) accommodative intraocular lens (IOL). METHODS:Thirteen eyes of eight patients implanted with the Tetraflex accommodating IOL for at least 2 years underwent assessment of their objective amplitude-of-accommodation by autorefraction, anterior chamber depth and pupil size with optical coherence tomography, and IOL flexure with aberrometry, each viewing a target at 0.0 to 4.00 diopters of accommodative demand. RESULTS:Pupil size decreased by 0.62+/-0.41 mm on increasing accommodative demand, but the Tetraflex IOL was relatively fixed in position within the eye. The ocular aberrations of the eye changed with increased accommodative demand, but not in a consistent manner among individuals. Those aberrations that appeared to be most affected were defocus, vertical primary and secondary astigmatism, vertical coma, horizontal and vertical primary and secondary trefoil, and spherical aberration. CONCLUSIONS:Some of the reported near vision benefits of the Tetraflex accommodating IOL appear to be due to changes in the optical aberrations because of the flexure of the IOL on accommodative effort rather than forward movement within the capsular bag

Comparison of dry and liquid carbon dioxide cutting conditions based on machining performance and life cycle assessment for end milling GFRP

In the present scenario, citizens' concern about environment preservation creates a necessity to mature more ecological and energy-efficient manufacturing processes and materials. The usage of glass fiber reinforced polymer (GFRP) is one of the emerging materials to replace the traditional metallic alloys in the automotive and aircraft industries. However, it has been comprehended to arise a sustainable substitute to conventional emulsion-based coolants in machining processes for dropping the destructive effects on the ecosystem without degrading the machining performance. So, in this study, the comparison of the two sustainable cutting fluid approaches, i.e., dry and LCO2, has been presented based on machining performance indicators like temperature, modulus of cutting force, tool wear, surface roughness, power consumption, and life cycle assessment (LCA) analysis for end milling of GFRP. The cutting condition of LCO2 has been found to be superior in terms of machining performance by providing 80% of lower cutting zone temperature, tool wear, 5% lower modulus of cutting force, and reduced surface roughness with 9% lower power consumption that has been observed in the case of LCO2 in comparison with dry machining. However, to compress the CO2 for converting in liquid form, a higher amount of energy and natural resources is consumed resulting in a higher impact on the environment in comparison with dry machining. Considering the 18 impact categories of ReCiPe midpoint (H) 2016, 95% higher values of impacts have been observed in the case of LCO2 in comparison with dry machining.Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature. The authors received financial support from Basque Government in the Excellence University Group system call, grant IT 1573-22

Evaluating the fabric performance and antibacterial properties of 3-D piezoelectric spacer fabric

The increasing need of on-demand power for enabling portable low-power devices and sensors has necessitated work in novel energy harvesting materials and devices. In a recent work, we demonstrated the production and suitability of three-dimensional (3-D) spacer all fibre piezoelectric textiles for converting mechanical energy into electrical energy for wearable and technical applications. The current work investigates the textile performance properties of these 3-D piezoelectric fabrics including porosity, air permeability, water vapour transmission and bursting strength. Furthermore, as these textiles are intended for wearable applications, we have assessed their wear abrasion and consequently provide surface resistance measurements which can affect the lifetime and efficiency of charge collection in the piezoelectric textile structures. The results show that the novel smart fabric with a measured porosity of 68% had good air (1855 l/m2/s) and water vapour permeability (1.34 g/m2/day) values, good wear abrasion resistance over 60,000 rotations applied by a load of 12 kPa and bursting strength higher than 2400 kPa. Moreover, the antibacterial activity of 3-D piezoelectric fabrics revealed that owing to the use of Ag/PA66 yarns, the textiles exhibit excellent antibacterial activity against not only Gram-negative bacteria E. coli but they are also capable of killing antibiotic methicillin-resistant bacteria S. aureus