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Although lubricants play an essential role in reducing wear and friction in mechanical systems, environmental issues persist. In the past decades, Ionic Liquids (ILs) have arisen as environmentally friendly alternatives to conventional lubricants and additives. ILs are low–volatile and non-flammable salts that possess low melting points (below 100 ºC). Their tunable properties, achieved by selecting the appropriate cation and anion, make them ideal candidates for different applications, including lubricants. In recent times, Protic Ionic Liquids (PILs) have attracted attention in the tribological community as a cost-effective alternative to conventional aprotic counterparts. In this work, a choline-amino acid ionic liquid, derived only from renewable, biodegradable, and biocompatible products, was synthesized, and investigated as both neat lubricant and additive to non-polar oil. The lubricating properties of [CHO][GLY] were studied both as a neat lubricant and as a 1 wt. % additive to a polyalphaolefin (PAO) oil using a ball-on-flat reciprocating friction tester. AISI 52100 steel disks were tested against AISI 52100 steel balls using either [CHO][GLY] or the mixture of PAO+[CHO][GLY]. For comparison purposes, the commercially available base oil, PAO, was also tested. Preliminary results showed no major differences in friction between the lubricants used. Nevertheless, the addition of 1 wt.% to the PAO demonstrated a remarkable 30% reduction in wear on the steel disk. This encouraging improvement in anti-wear characteristics raises the potential advancement of lubrication technology with the choline-amino acid ionic liquid, coupled with its environmentally friendly nature. Energy-dispersive X-ray (EDX) spectroscopy, non-contact profilometry, and scanning electron microscopy (SEM) were used to study the worn steel surfaces and elucidate the wear mechanisms.more » « lessFree, publicly-accessible full text available November 21, 2025
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Abstract The Cryogenic Underground Observatory for Rare Events (CUORE) is the first cryogenic experiment searching for
decay that has been able to reach the one-tonne mass scale. The detector, located at the Laboratori Nazionali del Gran Sasso (LNGS) in Italy, consists of an array of 988$$0\nu \beta \beta $$ crystals arranged in a compact cylindrical structure of 19 towers. CUORE began its first physics data run in 2017 at a base temperature of about 10 mK and in April 2021 released its$${\mathrm{TeO}}_{2}$$ result of the search for$$3{\mathrm{rd}}$$ , corresponding to a tonne-year of$$0\nu \beta \beta $$ exposure. This is the largest amount of data ever acquired with a solid state detector and the most sensitive measurement of$$\mathrm{TeO}_{2}$$ decay in$$0\nu \beta \beta $$ ever conducted . We present the current status of CUORE search for$${}^{130}\mathrm{Te}$$ with the updated statistics of one tonne-yr. We finally give an update of the CUORE background model and the measurement of the$$0\nu \beta \beta $$ $${}^{130}\mathrm{Te}$$ decay half-life and decay to excited states of$$2\nu \beta \beta $$ , studies performed using an exposure of 300.7 kg yr.$${}^{130}\mathrm{Xe}$$ -
Abstract CUORE Upgrade with Particle IDentification (CUPID) is a foreseen ton-scale array of Li 2 MoO 4 (LMO) cryogenic calorimeters with double readout of heat and light signals. Its scientific goal is to fully explore the inverted hierarchy of neutrino masses in the search for neutrinoless double beta decay of 100 Mo. Pile-up of standard double beta decay of the candidate isotope is a relevant background. We generate pile-up heat events via injection of Joule heater pulses with a programmable waveform generator in a small array of LMO crystals operated underground in the Laboratori Nazionali del Gran Sasso, Italy. This allows to label pile-up pulses and control both time difference and underlying amplitudes of individual heat pulses in the data. We present the performance of supervised learning classifiers on data and the attained pile-up rejection efficiency.more » « less
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Abstract The possibility that neutrinos may be their own antiparticles, unique among the known fundamental particles, arises from the symmetric theory of fermions proposed by Ettore Majorana in 1937 1 . Given the profound consequences of such Majorana neutrinos, among which is a potential explanation for the matter–antimatter asymmetry of the universe via leptogenesis 2 , the Majorana nature of neutrinos commands intense experimental scrutiny globally; one of the primary experimental probes is neutrinoless double beta (0 νββ ) decay. Here we show results from the search for 0 νββ decay of 130 Te, using the latest advanced cryogenic calorimeters with the CUORE experiment 3 . CUORE, operating just 10 millikelvin above absolute zero, has pushed the state of the art on three frontiers: the sheer mass held at such ultralow temperatures, operational longevity, and the low levels of ionizing radiation emanating from the cryogenic infrastructure. We find no evidence for 0 νββ decay and set a lower bound of the process half-life as 2.2 × 10 25 years at a 90 per cent credibility interval. We discuss potential applications of the advances made with CUORE to other fields such as direct dark matter, neutrino and nuclear physics searches and large-scale quantum computing, which can benefit from sustained operation of large payloads in a low-radioactivity, ultralow-temperature cryogenic environment.more » « less