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The objective of this study was to compare the laboratory slaking behavior of common clay-bearing rocks to their slaking behavior under natural climatic conditions observed during a 1-year experimental study. Five-cycle slake durability tests were performed in the laboratory on five claystones, five mudstones, five siltstones, and five shales. Twelve replicate specimens of each of these 20 rocks were also exposed to natural climatic conditions for 12 months. After each month of exposure, one replicate specimen of each rock was removed from natural exposure and its grain size distribution was determined. The results of laboratory tests and field experiment were compared in terms of 1st, 2nd, 3rd, 4th, and 5th cycle slake durability indices (Id 1 , Id 2 , Id 3 , Id 4 , Id 5 ), grain size distribution of slaked material, and disintegration ratio ( D R ), where D R is the ratio of the area under the grain size distribution curve of slaked material for a given specimen to the total area encompassing all grain size distribution curves of the specimens tested. Correlations of Id 1 , Id 2 , Id 3 , Id 4 , and Id 5 with D R values for laboratory specimens exhibit R 2 values of 0.87, 0.88, 0.83, 0.75, and 0.70, respectively. However, the relationship between Id 2 and D R , determined after 1, 3, 6, and 12 months of natural exposure, becomes weaker with increasing time of exposure, with R 2 values of 0.65, 0.63, 0.63, and 0.25, respectively. The fifth-cycle slake durability index (Id 5 ) for laboratory tested specimens shows a better correlation with D R values for naturally exposed specimens ( R 2 up to 0.80). A comparison of grain size distribution curves of slaked material for laboratory specimens, after the 2nd cycle slake durability test, with those of specimens exposed to natural climatic conditions shows that the laboratory test underestimates the field durability for claystones, and overestimates it for siltstones.

We propose a new measurement of the ratio of positron-proton to electron-proton elastic scattering at DESY. The purpose is to determine the contributions beyond single-photon exchange, which are essential for the Quantum Electrodynamic (QED) description of the most fundamental process in hadronic physics. By utilizing a 20 cm long liquid hydrogen target in conjunction with the extracted beam from the DESY synchrotron, we can achieve an average luminosity of 2.12 × 10 35  cm - 2 · s - 1  ( ≈ 200 times the luminosity achieved by OLYMPUS). The proposed two-photon exchange experiment (TPEX) entails a commissioning run at a beam energy of 2 GeV, followed by measurements at 3 GeV, thereby providing new data up to Q 2 = 4.6  (GeV/ c ) 2 (twice the range of current measurements). We present and discuss the proposed experimental setup, run plan, and expectations.

The search for a dark photon holds considerable interest in the physics community. Such a force carrier would begin to illuminate the dark sector. Many experiments have searched for such a particle, but so far it has proven elusive. In recent years the concept of a low mass dark photon has gained popularity in the physics community. Of particular recent interest is the 8 Be and 4 He anomaly, which could be explained by a new fifth force carrier with a mass of 17 MeV/ c 2 . The proposed Darklight experiment would search for this potential low mass force carrier at ARIEL in the 10-20 MeV/ c 2 e + e − invariant mass range. This proceeding will focus on the experimental design and physics case of the Darklight experiment.

Previous work has shown that it may be advantageous to use gasoline type fuels with long ignition delays compared to today's diesel fuels in compression ignition engines. In the present work we investigate if high volatility is also needed along with low cetane (high octane) to get more premixed combustion leading to low NOₓ and smoke. A single-cylinder light-duty compression ignition engine is run on four fuels in the diesel boiling range and three fuels in the gasoline boiling range. The lowest cetane diesel boiling range fuel (DCN = 22) also has very high aromatic content (75%vol) but the engine can be run on this to give very low NOₓ (< 0.4 g/kWh) and smoke (FSN < 0.1) e.g. at 4 bar and 10 bar IMEP at 2000 RPM like the gasoline fuels but unlike the diesel fuels with DCNs of 40 and 56. If the combustion phasing and delay are matched for any two fuels at a given operating condition, their emissions behaviour is also matched regardless of the differences in volatility and composition. However the same high aromatic, low cetane, diesel fuel can match different gasoline fuels depending on operating conditions - a result in line with previous understanding of autoignition quality from HCCI and knock studies.

Abstract The small binding energy of the hypertriton leads to predictions of the non-existence of bound hypernuclei for isotriplet three-body systems such as nnΛ. However, invariant mass spectroscopy at GSI has reported events that may be interpreted as the bound nnΛ state. The nnΛ state was sought by missing-mass spectroscopy via the (e, e′K+) reaction at Jefferson Lab’s experimental Hall A. The present experiment has higher sensitivity to the nnΛ-state investigation in terms of better precision by a factor of about three. The analysis shown in this article focuses on the derivation of the reaction cross-section for the 3H(γ*, K+)X reaction. Events that were detected in an acceptance, where a Monte Carlo simulation could reproduce the data well ($|\\delta p/p| \\lt 4\\%$), were analyzed to minimize the systematic uncertainty. No significant structures were observed with the acceptance cuts, and the upper limits of the production cross-section of the nnΛ state were obtained to be 21 and $31 \\, \\rm {nb} \\, \\rm {sr}^{-1}$ at the $90\\%$ confidence level when theoretical predictions of (−BΛ, Γ) = (0.25, 0.8) MeV and (0.55, 4.7) MeV, respectively, were assumed. The cross-section result provides valuable information for examining the existence of nnΛ.

We performed an experiment using tritium and hydrogen cryogenic gas targets at Thomas Jefferson National Accelerator Facility (JLab) in 2018 (E12-17-003)[1, 2]. In this article, we discuss the Λ/Σ0 hyperon electroproduction from hydrogen target. Elementary Λ/Σ0 hyperon production processes are important not only for an absolute mass scale calibration in our experiment, but also for the study of the electroproduction mechanisms themselves. In this article, we reported the results of the differential cross section for the p(e, e’K+)Λ/Σ0 reaction at Q2 ∼ 0.5 (GeV/c)2.

An nnΛ is a neutral baryon system with no charge. The study of the pure Λ-neutron system such as nnΛ gives us information on the Λn interaction. The nnΛ search experiment (E12-17-003) was performed at JLab Hall A in 2018. In this article, the Λn FSI was investigated by a shape analysis of the 3H(e, e′K+)X missing mass spectrum, and a preliminary result for the Λn FSI study is given.

Abstract We propose a new measurement of the ratio of positron-proton to electron-proton elastic scattering at DESY. The purpose is to determine the contributions beyond single-photon exchange, which are essential for the Quantum Electrodynamic (QED) description of the most fundamental process in hadronic physics. By utilizing a 20 cm long liquid hydrogen target in conjunction with the extracted beam from the DESY synchrotron, we can achieve an average luminosity of$$2.12\\times 10^{35}$$ 2.12 × 1035 cm$$^{-2}\\cdot $$ - 2 · s$$^{-1}$$ - 1 ($$\\approx 200$$ ≈ 200 times the luminosity achieved by OLYMPUS). The proposed two-photon exchange experiment (TPEX) entails a commissioning run at a beam energy of 2 GeV, followed by measurements at 3 GeV, thereby providing new data up to$$Q^2=4.6$$ Q2 = 4.6 (GeV/c)$$^2$$ 2 (twice the range of current measurements). We present and discuss the proposed experimental setup, run plan, and expectations.

We report the observations of the highly active FRb20201124A with the upgraded Giant Metrewave Radio Telescope at 550-750~MHz. These observations in the incoherent array mode simultaneously provided an arcsecond localization of bursts from \\rss, the discovery of persistent radio emission associated with the host galaxy, and the detection of 48 bursts. Using the brightest burst in the sample (\\(F= 108~{\\rm Jy~ms}\\)) we find a structure-maximizing dispersion measure of \\(410.8 \\pm 0.5~{\\rm pc~cm}^{-3}\\). We find that our observations are complete down to a fluence level of \\(10~{\\rm Jy~ms}\\), above which the cumulative burst rate scales as a power-law \\(R(>\\!F) = 10~{\\rm hr}^{-1} \\left(F/10\\mathrm{~Jy~ms}\\right)^{\\gamma}\\) with \\(\\gamma = -1.2 \\pm 0.2\\). We find that the bursts are on average wider than those reported for other repeating FRBs. We find that the waiting time between bursts is well approximated by an exponential distribution with a mean of \\(\\sim 2.9\\) min during our observations. We searched for periodicities using both a standard Fourier domain method and the Fast Folding Algorithm, but found no significant candidates. We measure bulk spectro-temporal drift rates between \\(-0.75\\) and \\(-20~{\\rm MHz~ms}^{-1}\\). Finally, we use the brightest burst to set an upper limit to the scattering time of 11.1~ms at 550~MHz. The localization of FRB20201124A adds strength to the proof-of-concept method described in our earlier work and serves as a potential model for future localizations and follow-up of repeating FRBs with the uGMRT.

We report a precise measurement of the parity-violating asymmetry \\(A_{\\rm PV}\\) in the elastic scattering of longitudinally polarized electrons from \\(^{48}{\\rm Ca}\\). We measure \\(A_{\\rm PV} =2668\\pm 106\\ {\\rm (stat)}\\pm 40\\ {\\rm (syst)}\\) parts per billion, leading to an extraction of the neutral weak form factor \\(F_{\\rm W} (q=0.8733\\) fm\\(^{-1}) = 0.1304 \\pm 0.0052 \\ {\\rm (stat)}\\pm 0.0020\\ {\\rm (syst)}\\) and the charge minus the weak form factor \\(F_{\\rm ch} - F_{\\rm W} = 0.0277\\pm 0.0055\\). The resulting neutron skin thickness \\(R_n-R_p=0.121 \\pm 0.026\\ {\\rm (exp)} \\pm 0.024\\ {\\rm (model)}\\)~fm is relatively thin yet consistent with many model calculations. The combined CREX and PREX results will have implications for future energy density functional calculations and on the density dependence of the symmetry energy of nuclear matter.