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In this review, we discuss recent developments in both the theory and the experimental searches of magnetic monopoles in past, current and future colliders and in the Cosmos. The theoretical models include, apart from the standard Grand Unifled Theories, extensions of the Standard Model that admit magnetic monopole solutions with flnite energy and masses that can be as light as a few TeV. Speciflcally, we discuss, among other scenarios, modified Cho{Maison monopoles and magnetic monopoles in (string-inspired, higher derivative) Born{Infeld extensions of the hypercharge sector of the Standard Model. We also outline the conditions for which effective field theories describing the interaction of monopoles with photons are valid and can be used for result interpretation in monopole production at colliders. The experimental part of the review focuses on, past and present, cosmic and collider searches, including the latest bounds on monopole masses and magnetic charges by the ATLAS and MoEDAL experiments at the LHC, as well as prospects for future searches. [ABSTRACT FROM AUTHOR]

The aim of this paper is to highlight the importance of raw materials in the production of ceramic artefacts. A brief but in-depth explanation is provided to emphasise the connections between raw materials and ceramic products. A step by step approach is developed with the aim of illustrating the different ceramic raw materials and their features and describing the effects of each component on the characteristics of the end products with particular attention to their function and use. When a potter makes an object in fact, this was already conceived thinking for a specific purpose. [ABSTRACT FROM AUTHOR]

Modelling flow and mass transfer of thermal separation equipment constitutes one of the most challenging tasks in fluids process engineering. The difficulty of this task comes from the multiscale multiphase flow phenomena in rather complex geometries. Both analysis of flow and mass transfer on different scales as well as validation of models and simulation results require advanced experimental and measurement techniques. As a follow‐up to intensive discussions during the 2019 Tutzing Symposium "Separation Units 4.0" a wide set of available modern experimental technologies is presented. [ABSTRACT FROM AUTHOR]

Radial inflow turbine and nozzle among the other components of the cryogenic turboexpander has a significant effect on the efficiency of the system. This study proposes an effective one-dimensional design approach of a radial turbine by introducing different loss correlations. The methodology also describes the effect of non-dimensional design variables on the performance of the turbine. These variables (blade speed ratio, pressure ratio, hub and shroud to turbine inlet radius ratio) undergo artificial intelligence-based model to predict their optimal range for better efficiency and power output of the turbine. Based on these optimal ranges, two turbine and nozzle models are generated. The results of the optimized configuration show that the turbine total-to-static efficiency and power output are higher by 4% and 18.9% respectively as compared to the existing literature. Thereafter, the three-dimensional computational fluid dynamics (CFD) analysis is carried out to visualize the fluid flow and thermal characteristics at different inlet temperatures in the flow passage using ANSYS CFX®. The study also focuses to identify the flow separation zone, tip leakage flow, vortex formation, secondary losses and its reasons at different spans of the turbine. An experimental platform is also established to validate the CFD results of a case study. The experimental results show that the mass flow rate and rotational speed has major effect on temperature drop and isentropic efficiency of the turboexpander. The study highlights the importance of the design methodology, the estimation capability of artificial intelligence models, the experimental techniques and benchmarking model for numerical analysis at different cryogenic temperature. [ABSTRACT FROM AUTHOR]

We investigated the porosity dependence of the restitution coefficient (ε) of porous ice balls with porosities of 49.6%, 53.8%, and 60.8% colliding with granite, ice and porous ice plates at a low impact velocity (v i = 0.93–96.9 cm s−1) and temperature of −13.8 °C. The relationship between the impact velocity and the restitution coefficient was divided into two regions by the critical velocity v c : In the quasi-elastic region (v i ≤ v c), the restitution coefficient had a constant value of ε qe regardless of the impact velocity and could be explained by using Dilley's viscous dissipation model. In the inelastic region (v i ≥ v c), the restitution coefficient decreased with the impact velocity and could be explained by using the improved Andrews' plastic deformation model. We then determined the porosity dependence of the ε qe and v c empirically for collisions between the porous ice ball and the porous ice plate from our results. Then we extrapolated the porosity dependence of the restitution coefficient by substituting the calculated ε qe and v c for the porosity of 10 to 70%. The restitution coefficient was found to decrease with increasing porosity of the porous ice, and to be strongly dependent on the porosity of the porous ice. Considering the energy budget in the steady-state dense ring system which is controlled by the restitution coefficient of the ring particles, the velocity dispersion of the ring particles was estimated to be ∼10−2 mm s−1 to cm s−1 for the ring particles with the porosity from 45% to 70% and < 10–90 cm s−1 for those with the porosity <45%. • We studied the effect of porosity of ice on the restitution coefficient. • Low-velocity impact experiments simulated collisions among Saturn's ring particles. • The restitution coefficient and deformation of porous ice were measured. • The energy dissipation mechanism was plastic and viscoelastic deformation. • We estimated the restitution coefficient of porous ice with a porosity of 10–70%. [ABSTRACT FROM AUTHOR]

Meteors are most often observed from the ground in the visible, most often at a distance of at least 80–100 km between the phenomenon and the observer. Such constraints lead to rough assumptions of the meteoroid's physical parameters for the data analysis. Wind tunnel experiments allow the scientists to fully characterize artificial meteors by means of a well known, controlled and calibrated environment. Here we present the first observation and full characterization of a 11.7 km/s equivalent meteor in M-IR band (3– 5 μ m). Real meteorites of different types were used in order to reproduce natural meteors in the laboratory environment. The measurements were taken with both an M-IR imaging camera and an M-IR spectrometer. We found that the overall aspect of the meteorite sample in the wind tunnel is similar in M-IR and visible bands. The M-IR spectrum shows a continuum (Planck's law), but no distinct emission lines of atoms or molecules. The derived temperatures lie in the range [ 1800 – 2500 ] K, regardless of the meteorite type. Discussions regarding the comparison with other experiments are presented. • First M-IR measurements of artificial meteors. • Black body radiation only (no emission line). • Measured temperature of 1800 – 2500 K regardless of the type of meteorite. • Light curve in M-IR seems to lag behind the visible one by 0.1 s or less. [ABSTRACT FROM AUTHOR]

Cellular materials have superior specific properties (e.g., specific strength, stiffness, and energy absorption) as compared to their monolithic material counterparts. With rapid advancements in additive manufacturing technology, the uniquely complex geometry of these materials – particularly periodic lattices – can be easily reproduced for additional experimental research, characterization, and potential industrial applications. This work utilizes the idea of shape transformers – previously employed to describe the structural efficiency of beams subjected to bending – to define new strut-based lattices, whose struts do not have the typical solid, circular cross-section shape. Both experimental and numerical model results have shown that this design parameter can be utilized to manipulate the crashworthiness efficiency of lattice materials. It is found that designing with a square or a rectangular cross-section could increase the plateau stress by up to 52% while increasing the mass normalized specific energy absorption by up to 32%. [Display omitted] • Broadly examines the energy absorption response of resin-based octet truss lattices. • Applies shape transformers to strut cross-section shape for unique lattice multiscale designs. • Discusses influence of shape second moment of area on crashworthiness performance. • Notes impact of non-circular shapes on overall response of octet truss lattices. [ABSTRACT FROM AUTHOR]

The high energy of meteoroid entering the Earth atmosphere presumably results in UV radiation. However, ground-based observations are impaired by the atmospheric absorption below 400 nm. Artificial meteors are produced in a high enthalpy wind tunnel, and observed with a [200–400] nm fiber-fed spectrometer in order to analyze for the first time the UV emission of meteors. Similarly to visible observations, several atomic lines of Fe and Mg are detected. Contrary to observations in the visible wavelength range, Si is also clearly detected in all tested samples. Carbon is not detected in atomic lines. As the strongest emission lines are detected between 220 and 330 nm, we recommend that future meteor dedicated space-based UV instruments focus on this particular wavelength interval. • First UV measurements of artificial meteors in the band [200–400] nm. • Strong emission lines between 220 and 330 nm. • Fe, Mg, Si detected in all tested samples but not C. [ABSTRACT FROM AUTHOR]

Nitrogen, carbon monoxide, and methane are key materials in the far outer Solar System where their high volatility enables them to sublimate, potentially driving activity at very low temperatures. Knowledge of their vapor pressures and latent heats of sublimation at relevant temperatures is needed to model the processes involved. We describe a method for using a quartz crystal microbalance to measure the sublimation flux of these volatile ices in the free molecular flow regime, accounting for the simultaneous sublimation from and condensation onto the quartz crystal to derive vapor pressures and latent heats of sublimation. We find vapor pressures to be somewhat lower than previous estimates in literature, with carbon monoxide being the most discrepant of the three species, almost an order of magnitude lower than had been thought. These results have important implications across a variety of astrophysical and planetary environments. • New vapor pressure measurements for N2, CO, and CH4 ices. • Uses quartz crystal microbalance to measure sublimation. • Accounts for simultaneous deposition from surrounding gas. • CO ice has lower vapor pressure than previously thought. [ABSTRACT FROM AUTHOR]

Various Solar System objects are covered in layers of ice that are dominated by H 2 O, CH 4 , and N 2 and in which complex chemical processes take place. In this work, the influence of composition and irradiation duration on the volatile irradiation products of mixed CH 4 :N 2 , CH 4 :H 2 O, and CH 4 :H 2 O:N 2 ices after electron irradiation are studied. The ices were irradiated for 2 or 4 h with 5 keV electrons, followed by a temperature programmed desorption, where the desorption of the volatile irradiation products was observed. The formation of C 2 H x and C 3 H x is observed in all ices and for both irradiation times. For the ices containing H 2 O, molecules as large as tentatively identified C 4 H x and C 5 H x are observed to co-desorb with water, whereas for CH 4 :N 2 a continuous desorption signal is observed instead of a sharp desorption peak. A decrease in signal intensity from the 2 to the 4 h irradiation is observed for most m/z signals in CH 4 :H 2 O and CH 4 :H 2 O:N 2 ices, whereas the opposite is recorded for CH 4 :N 2 , where in general larger signal for longer irradiation duration is seen. The addition of nitrogen to the CH 4 :H 2 O ice did not lead to clear identification of different molecules, but instead to a decrease of the observed signal for complex molecules, suggesting that the addition of nitrogen to the CH 4 :H 2 O mixture primarily leads to a more effective incorporation of material in an organic residue. The analysis of the residue will be subject of future work to complement the findings in this study. • Water in an irradiated ice changes the desorption behavior of complex molecules. • Addition of nitrogen to ices includes more complex molecules into organic residues. • Both of these points combined could have implications for comets and KBOs. [ABSTRACT FROM AUTHOR]

There exist numerous methods of experimentally testing designs for heat sinks in the laboratory, especially for microscale fluidic devices, which can lead to a problem for comparison between new studies and those in the literature. To explore this issue, laboratory-based experiments on the heat transfer and flow impedance properties of a sample microchannel heat sink were repeated over a varying range of equipment. Three types of heat source (hot plate, film heater and copper block with cartridge heaters), two types of piping (polymer and metal), and the presence or absence of manifolds were investigated and the differences in heat sink performance were noted. Overall, especially in terms of achieving consistent, repeatable results, it was found that the arrangement of copper block heater, metal piping and the inclusion of manifolds was superior for this particular microchannel device. Hence, it is suggested that future testing of heat sinks and heat exchanger devices employ a similar arrangement of equipment for greater accuracy and comparability. In particular, the plastic tubing and hot plate configurations were found to have relatively poor consistency when testing the heat sink, and the film heater produced non-uniform heating, even over a small surface area.

The work presents investigation on the water droplet impingement at a substrate with three different surface coating. The experiments are carried out for two temperatures of the surface: 23°C (room temperature) and −10°C. The water droplet contact is recorded via ultra-fast camera and simultaneously via fast thermographic camera. The wetting properties are changing for subzero temperatures of substrates.

Abstract A new approach for measuring the specific fracture energy of concrete denoted modified disk-shaped compact tension (MDCT) test is presented. The procedure is based on previous ideas regarding the use of compact tension specimens for studying the fracture behavior of concrete but implies significant modifications of the specimen morphology in order to avoid premature failures (such as the breakage of concrete around the pulling load holes). The manufacturing and test performance is improved and simplified, enhancing the reliability of the material characterization. MDCT specimens are particularly suitable when fracture properties of already casted concrete structures are required. To evaluate the applicability of the MDCT test to estimate the size-independent specific fracture energy of concrete (G F ), the interaction between the fracture process zone of concrete and the boundary of the MDCT specimens at the end of the test is properly analyzed. Further, the experimental results of G F obtained by MDCT tests for normal- and high-strength self-compacting concrete mixes are compared with those obtained using the well-established three-point bending test. The procedure proposed furnishes promising results, and the G F values obtained are reliable enough for the specimen size range studied in this work.

It has long been believed that most turbulent kinetic energy (TKE) dissipation occurs in the near-wall region between ejection and sweep events, i.e. beneath near-wall quasi-streamwise (Q-S) vortices, where wall-normal velocity fluctuations are locally zero. Contrary to this view, our experiments, carried out in a fully developed turbulent channel flow at Reτ = 205 by high-speed planar particle image velocimetry, show that the most intensive dissipative events occurring in the viscous sublayer are associated with very rare sweep events originating in the buffer region rather than with the ejections. We show that these rare events are the result of strong rotational motion of Q-S vortices which cause strong shear flow in the lower region of its downward side. Curiously, the same events are responsible for extreme TKE production taking place in the buffer region where its maximum is observed. [ABSTRACT FROM AUTHOR]

The cubic methylammonium lead chloride (CH3NH3PbCl3) perovskite has been investigated as a transparent conductor using the experimental method and well-known density functional theory (DFT). The X-ray diffraction (XRD) of the as-prepared film confirms the good crystallinity and cubic phase of the material. The lattice constants are calculated from XRD data and compared with the lattice constants predicted employing DFT. The bandgap of the film has been studied to investigate the electronic properties and compared with the calculated bandgap of bulk CH3NH3PbCl3 using DFT. In both the cases, the bandgap has been found to be direct in nature. Also, the partial and total density of states (PDOS and TDOS) have been discussed in detail. Further, the effective mass of electrons and holes are analyzed along the high symmetry points in the brillouin zone. The UV-VIS-NIR spectrometer has been used to measure the transmittance and reflectance of CH3NH3PbCl3 film and established that films are highly transparent in visible and near IR regions. The optical properties such as dielectric functions, refractive index and absorption coefficients of bulk CH3NH3PbCl3 perovskite have been calculated in the energy range 0-5 eV. All the calculated parameters are compared with the available experimental, and the theoretical state of art results and a fair agreement has been obtained between them. [ABSTRACT FROM AUTHOR]

Given current uncertainties in the cratering rates and geological histories of icy objects in the outer solar system, it is worth considering how the ages of icy surfaces could be constrained with measurements from future landed missions. A promising approach would be to determine cosmic-ray exposure ages of surface deposits by measuring the amounts of cosmogenic Lithium, Beryllium and Boron at various depths within a few meters of the surface. Preliminary calculations show that ice that has been exposed to cosmic radiation for one billion years should contain these cosmogenic nuclei at concentrations of a few parts per trillion, so any future experiment that might attempt to perform this sort of measurement will need to meet stringent sensitivity requirements. • Surface ages of icy worlds in the outer solar system are uncertain. • Cosmic-ray exposure ages are a promising method of measuring surface ages. • Such ages require measuring Li, Be or B concentrations at parts-per-trillion level. [ABSTRACT FROM AUTHOR]

The technique of cohesive zones makes it possible to evaluate the stability of the material, both at the beginning of the crack propagation and to the appearance and development of defects in the places of stress concentration. The ability to reliably determine the parameters of fracture of polymer composite materials and to predict the behavior of structural elements from them under loading is an urgent task for the aerospace industry. It is proposed to use the length of the cohesive zone in the finite-element 3D model for mode I of interfacial delamination of the carbon fiber composite laminates in the form of a double cantilever beam (DCB). The length of the cohesive zone is calculated from the experimentally determined parameters such as the local interlayer cohesive strength of the material and the critical strain energy release rate. The determined length of the cohesive zone is used in the model to select the minimum number of finite elements at their optimum size, which ensures a higher accuracy of calculations of the main parameters of fracture toughness of carbon fiber composite laminates. As a result of the research, the main parameters of crack resistance are determined and the optimal length of the interface elements is chosen. The obtained model accurately describes the process of crack growth along the entire length of the cohesive zone, and the results of its application correlate well with the results of the experiments. [ABSTRACT FROM AUTHOR]

In this study, shear relaxation properties of the porcine temporomandibular joint (TMJ) disc are investigated. Previous studies have shown that, in fatigue failure and damage of cartilage and fibrocartilage, shear loads could be one of the biggest contributors to the failure. The aim of the present study is to develop an evaluation method to study shear properties of the disc and to do a mathematical characterization of it. For the experiments, twelve porcine discs were used. Each disc was dissected from the TMJ and, then, static strain control tests were carried out to obtain the shear relaxation modulus for the central region of the discs. From the results, it was found that the disc presents a viscoelastic behavior under shear loads. Relaxation modulus decreased with time. Shear relaxation was 10% of the instantaneous stress, which implies that the viscous properties of the disc cannot be neglected. The present results lead to a better understanding of the discs mechanical behavior under realistic TMJ working conditions. [ABSTRACT FROM AUTHOR]

The rapid-neutron capture process (r process) is identified as the producer of about 50% of elements heavier than iron. This process requires an astrophysical environment with an extremely high neutron flux over a short amount of time (∼ seconds), creating very neutron-rich nuclei that are subsequently transformed to stable nuclei via β − decay. In 2017, one site for the r process was confirmed: the advanced LIGO and advanced Virgo detectors observed two neutron stars merging, and immediate follow-up measurements of the electromagnetic transients demonstrated an "afterglow" over a broad range of frequencies fully consistent with the expected signal of an r process taking place. Although neutron-star mergers are now known to be r -process element factories, contributions from other sites are still possible, and a comprehensive understanding and description of the r process is still lacking. One key ingredient to large-scale r -process reaction networks is radiative neutron-capture (n , γ) rates, for which there exist virtually no data for extremely neutron-rich nuclei involved in the r process. Due to the current status of nuclear-reaction theory and our poor understanding of basic nuclear properties such as level densities and average γ -decay strengths, theoretically estimated (n , γ) rates may vary by orders of magnitude and represent a major source of uncertainty in any nuclear-reaction network calculation of r -process abundances. In this review, we discuss new approaches to provide information on neutron-capture cross sections and reaction rates relevant to the r process. In particular, we focus on indirect, experimental techniques to measure radiative neutron-capture rates. While direct measurements are not available at present, but could possibly be realized in the future, the indirect approaches present a first step towards constraining neutron-capture rates of importance to the r process. [ABSTRACT FROM AUTHOR]

Abstract For in-situ geochemical analysis of the surface of Mars, laser-induced breakdown spectroscopy (LIBS) is a very useful technique and the first extraterrestrial LIBS instrument ChemCam will soon be followed by others. Appropriate normalization of real mission data that is taken under varying experimental and environmental conditions from diverse geologic samples is an ongoing topic. One approach is the scaling to emission line intensities of carbon and oxygen from the CO 2 -dominated low-pressure martian atmosphere as an internal standard. Here, we performed several experiments to examine the emission of carbon and oxygen from a simulated martian atmosphere on simple, mostly mono-elemental samples, and to compare the emission characteristics of the elements of both origins. Differences in laser irradiance were found to have the biggest impact on sample emission lines scaled to C and O emission of the atmosphere. The temporal behavior shown in time-resolved LIBS measurements is dominated by the degree of ionization, but the ratio of the neutral emission from the sample to neutral emission from the atmosphere also varies over time. The effect of different grain sizes was minor in comparison to the high intrinsic variation in the LIBS data. Different samples were found to affect the absolute intensity of atmospheric C(I) more than O(I). Furthermore, the C(I) emission was found to be inseparably superimposed by iron if the latter was present in the target. The results indicate limitations of the general suitability of atmospheric carbon and oxygen emission for normalization purposes of martian LIBS data. Highlights • Emission of atmospheric carbon and oxygen appears in all martian LIBS data. • Atmospheric C and O emission is affected by experimental parameters and the sample. • In particular varying laser irradiance can result in changes of emission line ratios. • Atmospheric O(I) emission is less affected by sample matrix than C(I) emission. • C(I) at 247 nm is inseparably superimposed by iron emission. [ABSTRACT FROM AUTHOR]

Abstract A finite-strain hyperelastic phenomenological constitutive damage model is proposed to model the rate-independent failure behavior of rubber-like materials under isothermal conditions. At large strain, non-local gradient-enhanced damage model has been formulated and numerically implemented to predict the initiation and propagation of damage in rubber-like materials. The theoretical framework is based on the Internal State Variables (ISV) approach and has been implemented in the commercial finite element code Abaqus via User Element subroutine (UEL). Robustness of the model was systematically investigated by undertaking the parametric study on the influence of damage parameters, both local and non-local, on the overall constitutive behavior of the material. The veracity of the theoretical framework was tested by quantitatively comparing the capability of the model to predict the onset of damage, its propagation and the corresponding load-displacement response of nitrile butadiene rubber material under quasi-static condition. Finally, the mesh objectivity simulations from the non-local model are presented for rubber under fatigue loading. [ABSTRACT FROM AUTHOR]

Energy efficiency labeling programs are worldwide applied to provide energy savings (electrical, mechanical, thermal, etc.) in machines and equipment for residential and industrial use, and also a potential reduction in greenhouse gas emissions. Actual research and development indicate that low-pressure axial flow fans represent a significant amount of energy consumption (electricity) especially in developing countries with warm climates, as in Brazil. In this work, bench tests were performed at university facilities, taking into account Brazilian standards for energy efficiency (Brazilian Labeling Program) for residential fans. Equipment under test is a free blow fan (desktop type, residential use), three-bladed with 500 mm diameter and angular speed ranging from ~ 500 up to 1500 s−1. Experimental analysis and measurement employed hot-wire anemometry, tachometer, wattmeter, chronometer, and data acquisition system. The results are for performance evaluation of turbomachinery characteristic curves. It includes airflow (m3 s−1), angular speed (s−1), the power supplied/received (W), efficacy ηENCE,n [(m3 s−1 W) m], and non-dimensional parameters: efficiency η (%) and design flow rate, as well as velocity field, among others. Main contributions indicate that (a) velocity and airflow in turbulent and fully developed conditions are consistent with energy efficiency and efficacy literature comparison, (b) power received by the fluid flow increases ten times more than supplied electrical energy (17/1.8), in the test range, (c) maximum energy conversion efficiency is ηmáx ~ 33% at ~ 1300 RPM and nominal flow rate φ ~ 0.165, (d) efficacy is lower than 0.0030 {[(m3 s−1) W)] m}, classified in "D" level, and (e) expected energy savings ~ 30% by reaching "A" efficacy levels. [ABSTRACT FROM AUTHOR]

Highlights • Use of Thermal Impedance and Damage Metric is proposed for breast cancer detection. • Presence of inclusions was detected without the knowledge of thermal properties. • Only the knowledge of temperature and heat flux measurements was required. • Small inclusion sizes were detected in silicone phantom sample. • The technique can be applied on people with low mobility or dense breast tissue. Abstract Tumors can be detected from a temperature gradient owing to the high vascularization and increased activity of cancer cells. The identification of affected areas through thermal infrared images represents a method of identifying these tumors. However, various disease processes can produce significant and unpredictable changes in body temperatures. These limitations suggest that thermal image should be used as an adjuvant examination, not a diagnostic test. The objective of this study was to develop a method that could qualify thermographic techniques for the detection of inclusions and could be used as an alternative. The proposed method used a thermal analogy with dynamic systems for inclusion detection by changing the impedance of these systems. The impedance was the ratio between the variations of the surface temperature response of the structure to the application of a modulated external heat flux. The damage metrics quantitatively represented the difference between two measurements before and after damage. The proposed procedure was validated experimentally through an application in hyperplastic materials with simple geometry. Silicone phantom samples were analyzed. The impedance method showed sensitivity to small inclusion sizes, representing an early detection capability. [ABSTRACT FROM AUTHOR]

Melting probes are a proven tool for the exploration of thick ice layers and clean sampling of subglacial water on Earth. Their compact size and ease of operation also make them a key technology for the future exploration of icy moons in our Solar System, most prominently Europa and Enceladus. For both mission planning and hardware engineering, metrics such as efficiency and expected performance in terms of achievable speed, power requirements, and necessary heating power have to be known. Theoretical studies aim at describing thermal losses on the one hand, while laboratory experiments and field tests allow an empirical investigation of the true performance on the other hand. To investigate the practical value of a performance model for the operational performance in extraterrestrial environments, we first contrast measured data from terrestrial field tests on temperate and polythermal glaciers with results from basic heat loss models and a melt trajectory model. For this purpose, we propose conventions for the determination of two different efficiencies that can be applied to both measured data and models. One definition of efficiency is related to the melting head only, while the other definition considers the melting probe as a whole. We also present methods to combine several sources of heat loss for probes with a circular cross-section, and to translate the geometry of probes with a non-circular cross-section to analyse them in the same way. The models were selected in a way that minimizes the need to make assumptions about unknown parameters of the probe or the ice environment. The results indicate that currently used models do not yet reliably reproduce the performance of a probe under realistic conditions. Melting velocities and efficiencies are constantly overestimated by 15 to 50 % in the models, but qualitatively agree with the field test data. Hence, losses are observed, that are not yet covered and quantified by the available loss models. We find that the deviation increases with decreasing ice temperature. We suspect that this mismatch is mainly due to the too restrictive idealization of the probe model and the fact that the probe was not operated in an efficiency-optimized manner during the field tests. With respect to space mission engineering, we find that performance and efficiency models must be used with caution in unknown ice environments, as various ice parameters have a significant effect on the melting process. Some of these are difficult to estimate from afar. • Ice melting probes are a key technology for the exploration of icy moons. • Performance and efficiency models evaluate logged operational parameters. • Model validation using field data from Alpine and Antarctic analogue environments. • Efficiency and penetration rate are overestimated by the current models. [ABSTRACT FROM AUTHOR]

• Operational flexibility of hydraulic turbines and impediments in realizing such flexibility are discussed. • Experimental research on draft tube flow instability and consequent effects is discussed in-depth. • Cavitation in vortex ropes over a range of operating points is discussed. • Research on vortex breakdown phenomenon is discussed in relevance to flow anomaly in hydraulic turbine draft tubes. Operational flexibility of hydraulic turbines is impeded by the vortex breakdown phenomenon. The phenomenon, a consequence of instability in vortical flows in general, manifests as a rotating structure called vortex rope located in the central zone of a draft tube diffuser in case of hydraulic turbines. Occurrence of vortex breakdown is ascribed to an instability prone swirl in the flow exiting the runner at off-design operating conditions, the part load and high load. The intended point of operation by design, the best efficiency point, however, yields a nearly swirl-free flow at the runner outlet and as such is devoid of vortex breakdown. Formation of the rotating vortex rope causes low frequency pressure fluctuation which may transmit to the entire hydraulic circuit. Power swings may occur if the frequency of pressure fluctuation resonates with the system natural frequency. Due to chaotic flow, losses in the diffuser increase and pressure recovery is compromised leading to a drop in efficiency. This work deconstructs and links the important literature to build a holistic understanding of the vortex breakdown phenomenon and related effects in hydraulic turbines. [ABSTRACT FROM AUTHOR]

• Design and development of an automatic thermo-mechanical testing apparatus. • Three materials were tested at varying strain rates and temperatures. • The device was validated with Hopkinson bar experiments on S235JR steel. • Numerical simulations were performed to analyse the experimental observations. Dynamic testing of materials is necessary to model high-speed forming processes (e.g. hammer forging, blanking, forming, etc.) and crash/impact behaviour of structures, amongst others. The most common machines to perform medium to high-speed tests are the servo-hydraulic high-speed tensile and compression machines and the Hopkinson bars. The paper analyses the use of a newly-developed laboratory testing facility, named the Automatic Thermo-Mechanical Tester (ATMT). This testing machine is equipped with a pneumatically accelerated Direct Impact Drop Hammer (DIDH), a furnace and automatised robotic arm, capable of characterising materials at intermediate strain rates, ranging from 100 to 300 s−1 in combination with temperatures up to 1350 °C. The hammer has been designed and constructed to conduct a variety of material characterisation tests, such as, upsetting or plane strain compression tests as well as component tests for validation purposes. The DIDH allows testing standard compression specimens at average strain rates in the order of 100 s−1 that decrease progressively until the it is fully stopped. It is, in combination with universal testing machines and Hopkinson bar systems, particularly suitable for experimental validation of loading-rate dependant material models. Compression tests were conducted with different hammer impact velocities generating a variety of strain rates at varying temperatures on S235JR structural steel, OFHC copper and wrought Inconel 625 nickel-based superalloy to assess the potential of the novel apparatus. A detailed finite element numerical study of the system was performed to assess several aspects such as the effect of the specimen geometry or its capability as an intermediate testing device, simulating a simplified system and the full Direct Impact Drop Hammer apparatus. [ABSTRACT FROM AUTHOR]

At present, cosmic ray (CR) physics uses a considerable variety of methods for studying CR char-acteristics of both primary and secondary fluxes. Experimental methods make the main contribution, using various types of detectors, but numerical methods increasingly complement it due to the active development in computer technology. This approach provides researchers with the most extensive infor-mation about details of the process or phenomenon and allows us to make the most competent conclu-sions. This paper presents a concept of the RUSCOSMIC © software package based on the GEANT4 toolkit and representing a range of different numerical models for studying CR propagation through medium of different systems (radiation detectors, Earth’s atmosphere). The obtained results represent response functions of the main radiation detectors as well as some typical characteristics of secondary CR fluxes. Comparative results also show the operation of the module verification of calculations with experimental data.

Experimental methods are indispensable for the study of the function of biological macromolecules, not just as static structures, but as dynamic systems that change conformation, bind partners, perform reactions, and respond to different stimulus. However, providing a detailed structural interpretation of the results is often a very challenging task. While experimental and computational methods are often considered as two different and separate approaches, the power and utility of combining both is undeniable. The integration of the experimental data with computational techniques can assist and enrich the interpretation, providing new detailed molecular understanding of the systems. Here, we briefly describe the basic principles of how experimental data can be combined with computational methods to obtain insights into the molecular mechanism and expand the interpretation through the generation of detailed models.

A simple and effective technique to characterize the photoconductivity (PC) of lithium niobate is presented. The technique is based on the modulation of the external field and on the observation of the optical response of the material as a function of the intensity of a gaussian beam using a Tardy’s polarimetric setup in the r 22 configuration. When the temporal period of the modulation is larger than the Maxwell time of the material, the effect of the PC can be detected observing the kinetics of the screening effect of the external applied field. This approach allows measuring a wide dynamic range up to high light intensities with good accuracy using a standard oscilloscope and with no need for charge collection electrodes. The technique is demonstrated by comparing two samples, the first possessing a standard congruent composition, the second being doped with Zn in order to boost the PC.

Ventilated façades are applied in both new and existing buildings. It has been claimed that these components help to reduce energy use in buildings and improve occupant comfort. However, their performance strongly depends on the airflow passing through the cavity. In order to characterise and to model the behaviour of the ventilation and its effectiveness, the components need to be tested in the laboratory, as well as under real dynamic weather conditions. Despite the steadily growing research in this area, there are few studies with conclusive results about the reliability of existing experimental procedures for characterisation of airflow in the ventilated cavities. The aim of this paper is to describe and review recent state of the art experimental assessments for the airflow characterisation in ventilated cavities. The paper starts with a short introduction on the potentialities and limitations of different experimental methodologies, and continues with a detailed classification and description of the most relevant monitoring techniques for airflow in air cavities of façades that have been developed in recent years.

Ice-binding proteins (IBPs) are proteins that have the remarkable ability to bind to ice, and their study has intrigued researchers for decades. This chapter explores the importance of structural biology in understanding IBPs and highlights the significant contributions of IBPs to the field of structural biology. The structures of various IBPs from different organisms have been elucidated, revealing key elements involved in ice binding. Structural biology techniques, including nuclear magnetic resonance (NMR) spectroscopy, transmission electron cryo-microscopy (cryo-EM), and X-ray crystallography, play crucial roles in solving protein structures. This article focuses on X-ray crystallography as a tool for investigating IBP structures, providing insights into its theoretical and practical aspects, experimental workflows, and common pitfalls to avoid., (© 2024. The Author(s), under exclusive license to Springer Science+Business Media, LLC, part of Springer Nature.)

Highlights • In situ cryogenic trap in a plasma discharge enables quantification of gas-phase precursors in Titan-like conditions • C 2 H 4 is a major hydrocarbon precursor to tholin formation • HCN and NH 3 are also important volatile products • NH 3 is the most abundant product formed with a 1% CH 4 mixing ratio Abstract The Cassini Mission has greatly improved our understanding of the dynamics and chemical processes occurring in Titan's atmosphere. It has also provided us with more insight into the formation of the aerosols in the upper atmospheric layers. However, the chemical composition and mechanisms leading to their formation were out of reach for the instruments onboard Cassini. In this context, it is deemed necessary to apply and exploit laboratory simulations to better understand the chemical reactivity occurring in the gas phase of Titan-like conditions. In the present work, we report gas phase results obtained from a plasma discharge simulating the chemical processes in Titan's ionosphere. We use the PAMPRE cold dusty plasma experiment with an N 2 CH 4 gaseous mixture under controlled pressure and gas influx. An internal cryogenic trap has been developed to accumulate the gas products during their production and facilitate their detection. The cryogenic trap condenses the gas-phase precursors while they are forming, so that aerosols are no longer observed during the 2 h plasma discharge. We focus mainly on neutral products NH 3 , HCN, C 2 H 2 and C 2 H 4. The latter are identified and quantified by in situ mass spectrometry and infrared spectroscopy. We present here results from this experiment with mixing ratios of 90–10% and 99–1% N 2 CH 4 , covering the range of methane concentrations encountered in Titan's ionosphere. We also detect in situ heavy molecules (C 7). In particular, we show the role of ethylene and other volatiles as key solid-phase precursors. [ABSTRACT FROM AUTHOR]

Corrosion was generated by the action of a jet impingement flow of sour brine on pipeline steel samples of X70. Flow-assisted corrosion affected nature, number and peak intensity of the chemical species formed as corrosion products. Iron sulfides predominated in static and low flow rate conditions (1.1 m/s), whereas at 2.4 m/s iron oxides were mainly formed, which led to higher corrosion rates and suggested that oxides are less protective than sulfides. On inhibition, imidazoline seems to mitigate oxide formation and support sulfide formation balancing both species on steel surface. Ferrite phase in laminar pearlite was preferentially dissolved with/without inhibitor, and mackinawite (FeS2) was formed at every flow rate, angle with and without inhibitor. Theoretical stresses determined by computational flow dynamics for corrosion product removal showed a fair approximation to those proposed in the literature. [ABSTRACT FROM AUTHOR]

In this review, we survey the recent advances in nonlinear optics and the applications of two-dimensional (2D) materials. We briefly cover the key developments pertaining to research in the nonlinear optics of graphene, the quintessential 2D material. Subsequently, we discuss the linear and nonlinear optical properties of several other 2D layered materials, including transition metal chalcogenides, black phosphorus, hexagonal boron nitride, perovskites, and topological insulators, as well as the recent progress in hybrid nanostructures containing 2D materials, such as composites with dyes, plasmonic particles, 2D crystals, and silicon integrated structures. Finally, we highlight a few representative current applications of 2D materials to photonic and optoelectronic devices. [ABSTRACT FROM AUTHOR]