bluuebunny/crossref_metadata_2025_split huggingface dataset:
Beam test studies with silicon sensor module prototypes for the CMS Phase-2 Outer Tracker
Authors: Wittig F. , Koppenhöfer R. , Maier S. , Nürnberg A. 
Published: January 2023

Abstract
The Large Hadron Collider (LHC) at CERN will be upgraded to the High-Luminosity LHC (HL-LHC) by 2029. In order to fully exploit the physics potential of the high luminosity era the experiments must undergo major upgrades. In the context of the upgrade of the Compact Muon Solenoid (CMS) experiment the silicon tracker will be fully replaced. The outer part of the new tracker (Outer Tracker) will be equipped with about 13,000 double-layer silicon sensor modules with two different flavors: PS modules consisting of a macro-pixel and a strip sensor and 2S modules using two strip sensors. These modules can discriminate between trajectories of charged particles with low and high transverse momentum. The different curvature of the trajectories in the CMS magnetic field leads to different hit signatures in the two sensor layers. By reading out both sensors, matching hits in the seed and correlation layer “stubs” are identified. This stub information is generated at the LHC bunch crossing frequency of 40 MHz and serves as input for the first stage of the CMS trigger. In order to quantify the hit and stub detection efficiency, beam tests have been performed. This article comprises selected studies from measurements gathered during two beam tests at the DESY test beam facility with 2S prototype modules assembled in 2021, featuring the Low Power Gigabit Transceiver (lpGBT). In order to compare the module performance at the beginning and end of the CMS runtime, a module with irradiated components has been built and intensively tested.
Design and preliminary results of a shunt voltage regulator for a HV-CMOS sensor in a 150 nm process
Authors: Powell S. , Hammerich J. , Karim N. , Vilella E. , Zhang C. 
Published: January 2023

Abstract
This paper presents the design and preliminary results of a shunt voltage regulator and two different bandgap reference designs for use with a monolithic High Voltage CMOS (HV-CMOS) sensor in a 150 nm technology node. One bandgap reference design is based on Bipolar Junction Transistors (BJTs) as the reference element of the circuit — the rest of the circuit is entirely designed with Metal–Oxide–Semiconductor Field-Effect Transistors (MOSFETs). The second bandgap reference design makes use of MOSFETs exclusively.
Visualisation of sulphur on single fibre level for pulping industry
Authors: Norlin B. , An S. , Granfeldt T. , Krapohl D. , Lai B. , Rahman H. , Zeeshan F. , Engstrand P. 
Published: January 2023

Abstract
In the pulp and paper industry, about 5 Mt/y chemithermomechanical pulp (CTMP) are produced globally from softwood chips for production of carton board grades. For tailor making CTMP for this purpose, wood chips are impregnated with aqueous sodium sulphite for sulphonation of the wood lignin. When lignin is sulphonated, the defibration of wood into pulp becomes more selective, resulting in enhanced pulp properties. On a microscopic fibre scale, however, one could strongly assume that the sulphonation of the wood structure is very uneven due to its macroscale size of wood chips. If this is the case and the sulphonation could be done significantly more evenly, the CTMP process could be more efficient and produce pulp even better suited for carton boards. Therefore, the present study aimed to develop a technique based on X-ray fluorescence microscopy imaging (µXRF) for quantifying the sulphur distribution on CTMP wood fibres. Firstly, the feasibility of µXRF imaging for sulphur homogeneity measurements in wood fibres needs investigation. Therefore, clarification of which spatial and spectral resolution that allows visualization of sulphur impregnation into single wood fibres is needed. Measurements of single fibre imaging were carried out at the Argonne National Laboratory’s Advanced Photon Source (APS) synchrotron facility. With a synchrotron beam using one micrometre scanning step, images of elemental mapping are acquired from CTMP samples diluted with non-sulphonated pulp under specified conditions. Since the measurements show significant differences between sulphonated and non-sulphonated fibres, and a significant peak concentration in the shell of the sulphonated fibres, the proposed technique is found to be feasible. The required spatial resolution of the µXRF imaging for an on-site CTMP sulphur homogeneity measurement setup is about 15 µm, and the homogeneity measured along the fibre shells is suggested to be used as the CTMP sulphonation measurement parameter.
A silicon vertex detector with timing for the Upgrade II of LHCb
Authors: Haimberger J. 
Published: January 2023

Abstract
The LHCb Upgrade II aims at maximizing the potential for heavy flavour physics at high luminosity-LHC. The Vertex Locator (VELO) plays an important role in this task due to its excellent tracking and vertexing abilities. During Run 5 and 6, the detector will undergo through a substantial increase in data rate, pile-up and radiation damage. To achieve the same vertex reconstruction efficiency as the current Upgrade I detector, the introduction of timing and its possible implementations are discussed. Additional requirements for new sensor and ASIC technologies, introduced to cope with increased radiation damage, data rate and timing, are also presented. Finally, possible new detector layouts, adapted to expected conditions, are discussed and their impact on the RF-foil and vacuum tank geometries are treated.
The inherent trade-off between the environmental and anti-poverty goals of payments for ecosystem services
Authors: Jayachandran Seema 
Published: January 2023

Abstract
Conservation programs in low-income countries often have dual goals of protecting the environment and reducing poverty. This article discusses the tension between these two goals in payments for ecosystem services (PESs) programs. Participants who undertake a pro-environment behavior receive a payment, which can be decomposed into two parts: the amount that compensates them for the cost of changing their behavior and the extra amount that is a ‘pure transfer’ to them. To maximize the program’s environmental benefits, a policy maker would like to set the pure transfer component to zero, yet the pure transfer is the only part of the payment that increases participants’ economic well-being. In practice, PES programs pay out some pure transfers, and the extent of the anti-poverty benefits depends on whether the pure transfers are de facto targeted to the poor. I lay out these points and then illustrate them with data from a randomized trial of payments for forest protection in Uganda. I provide evidence that the economic gains from participation in PES are indeed larger for those with low costs to fulfill the program’s conservation requirements. I also show that, in this context, poorer eligible households enjoyed more improvement in their economic well-being than richer ones did.
Effect of uncertainties on block volume estimation
Authors: Carriero M T , Ferrero A M , Migliazza M R , Umili G 
Published: January 2023

Abstract
The combination of the aleatory nature of the rock mass structure and the epistemic errors related to the survey methods make rock mass characterization a challenge despite the remarkable evolution of the survey tools and the research on the subject. In particular, significant uncertainties affect block volume estimation: the need for simplification connected to the engineering approach to rockfall problems, for instance, risks to mask the ripple effect of uncertainties on the reliability of the results. Even considering a simplified shape of the block created by three sets of discontinuities (i.e., a prism), the uncertainties on the geometrical characteristics of the discontinuities (orientation, spacing, and persistence) greatly influence the resulting volume distribution. It is a fact that a single value of the volume cannot be representative of the rock mass: the In Situ Block Size Distribution (IBSD) should be built to describe the variability of block volumes. Many statistical distribution functions can be used for fitting spacing data (i.e., gamma, negative exponential, log-normal, Weibull). The choice of the function must follow a rigorous evaluation of the goodness of fit. This research aims to assess the influence of the uncertainties related to the discontinuities sets, with particular reference to spacing samples, on block volume estimation. Through numerical examples and a case study, this research shows that a reduction of uncertainty can be reached by rigorous statistical processing of the data.
Study of size effects on the peak and residual strength of intact and artificially fissured granite samples
Authors: González-Fernández M A , Estévez-Ventosa X , García-Bastante F , Alejano L R , Ferrero A M 
Published: January 2023

Abstract
There are not many studies on jointed rock specimens, which can be considered small scale rock mass analogs. On the other hand, the scale effects in the mechanical properties of such samples have seldom been studied. With the aim of continuing previous research on intact granite rocks, the authors have carried out sets of 25 stress-strain triaxial compressive tests on 1 sub-vertical and 2 sub-horizontal 38 mm, 54 mm and 84 mm diameter jointed granite specimens at various confinements. Peak and residual strength values were obtained and compared to those recovered form intact rock samples. Results suggest that peak strength follows similar trends with scale to those observed on intact rock, even if lower strength values are logically recorded. Regarding residual strength, the obtained results are in line with those observed trends for standard size samples, showing a similar trend for all cases independently of scale, even if we observe larger variability for jointed samples. The authors have also compared the values fitting the generalized Hoek-Brown criterion for rock masses to better understand the behavior in relation to sample size. So scale effects clearly appear on jointed rock peak strength of jointed sample; even if residual strength seems hardly affected by scale.
Evaluating face stability in mountain tunnel excavation by inclination monitoring at the tunnel crown - Atoda tunnel case study
Authors: Sakai K , Yamagami M , Tani T , Fumimura K 
Published: January 2023

Abstract
The authors have been developing a prediction method for changes of ground stiffness ahead of a tunnel face by monitoring inclination at the tunnel crown (along the face advance axis). During the Atoda tunnel construction project, inclination monitoring was conducted at measurement intervals of 10 m. This is the first tunneling project practically using the proposed method throughout the excavation length. There is used a newly developed tilt sensor equipped with a Low-Power and Wide-Area (LPWA) wireless communication system that collects inclination data and transmits it to a data gateway automatically. During excavation work zones of weathered and fractured tuff breccia were recognized; face instability and partial collapse were experienced at those locations, though tunnel deformation was generally no more than 10 mm. Inclination values had a tendency to decrease in tunnel advance direction before the face encountered the soft/weak weathered rock, verifying the effectiveness of the method for monitoring tunnel stability and safety.
Dynamic compressive behaviour of Rewa shale through SHPB tests
Authors: Deshpande V M , Chakraborty T 
Published: January 2023

Abstract
The present work investigates the high strain rate behaviour of transversely isotropic Rewa shale using a split Hopkinson pressure bar. Rewa shale, a type of Vindhyan shale, is collected from Rewa district in the Madhya Pradesh state of India. Samples are loaded at various strain rates ranging from 110/s to 874/s. It is found that the compressive strength is rate-dependent, and it increases as the strain rate rises. The highest compressive strength is exhibited by samples at 0° and 90°. Samples at 30°, 45° and 60° fail at higher strains and strain rates. All samples subjected to dynamic compressive loading are pervasively fragmented. The results can potentially be applied to improve drilling and blasting operations.
The pressure dependent elastic anisotropy of Grimsel granite and Bukov paragneiss
Authors: Aminzadeh A , Petruzalek M , Vavrycuk V , Lokajicek T 
Published: January 2023

Abstract
A methodology for obtaining the stiffness tensor of an elastic material in its most general form (with 21 independent parameters) using ultrasonic measurements is presented. The methodology is used to define the anisotropic properties of two spherical rock samples: a migmatized gneiss from Bukov (Czech Republic) and a granite from Grimsel (Switzerland) underground research laboratories. The general stiffness matrix for both rocks is determinded for different confining pressures suggesting that the Bukov sample is orthotropic at atmospheric pressure while the Grimsel sample is transversely isotropic. However, the Bukov sample remains orthotropic even at a high pressure of 100 MPa but the Grimsel sample becomes almost isotropic. Both rocks are anisotropic under the overburden pressure acting at the in-situ URL conditions. A significant amount of cracks remains open at these pressures and contribute to the overall anisotropy of rocks.
Analysis of the Permeability Change Resulting from Active Mineral Precipitation in Pores of Rocks by 3D-DEM
Authors: Arkin Eldan , Mori Takumi , Himeno Ren , Sainoki Atsushi , Sato Akira 
Published: January 2023

Abstract
Carbon dioxide capture and storage (CCS) is a promising technique for reducing the concentration of CO2 in the atmosphere, and several million tons of CO2 are sequestered every year. The most important problem in CCS is ensuring aquifer safety. However, there is still room for improvement in the flow characteristics of aquifers to prevent CO2 leakage. To decrease the permeability of porous rocks, in this study, a method called ‘active mineral deposition’ was developed. In this method, some minerals are actively precipitated in aquifers, and the pores in the rock mass are closed by precipitated minerals. Because the pores are closed and stacked by minerals, the permeability of the rock mass is expected to decrease. For the precipitated minerals, CaCO3 is a promising mineral, and CaCO3 is precipitated in the pores of rocks. From microscopic observation, the approximate size of the precipitated mineral was estimated to be 10 μm in the rock pores. To verify the effect of the method, the permeability of the porous rocks was simulated using the three-dimensional discrete-element method (3D-DEM). Here, the rock minerals and pores were simulated using DEM elements, and the initial permeability of the models was estimated. Then, the small minerals, which represent precipitated minerals, were generated in the pore space, and changes in the intrinsic permeability, flow path, and pressure distributions in the rocks were estimated. The value of intrinsic permeability decreased to one tenth of the initial condition when 1% of the pore spaces were occupied by the precipitated minerals. A small amount of precipitation could change the permeability of the porous materials.
Validation of the Crack Mode-Changing Stress in Circular Tunnels Under Generalized Triaxial Tensile Stress States
Authors: Mutaz E , Serati M , Williams D J , Quintero O S 
Published: January 2023

Abstract
In the past century, mining depths have increased profoundly from a few hundred meters to several kilometres following improvements in drilling techniques and instrumentation methods. In highly-stressed tunnels, the predominant failure mechanism of underground rock is controlled by stress-induced fractures parallel to the excavation boundaries in terms of spalling failures or, in some severe cases, a violent slab ejection that forms a V-shaped notch around the excavation walls. Such failures can seriously affect production and shut down the operation temporarily or even permanently. To better characterize, predict, and prevent these catastrophic failures, many laboratory tests and scaled model tunnels have been conducted under uniaxial and biaxial loading conditions, with limited studies also available under true triaxial stress states. This paper extends the previous studies on the impact of true triaxial loading conditions on the spalling failure in high porosity sandstone and investigates further the validation of a new Crack Mode-Changing Stress (CMCS) parameter, defined as the minimum principal stress required to change rock fracturing from splitting to a sliding failure mode. The results revealed that the minor principal stress can significantly affect the propagation of the stress-induced fractures of spalling failure along the tunnel sidewall.
Instrumental response of borehole tensor strainmeters for oblique-incident seismic waves
Authors: Tian Jiayong , Zhang Kanghua , Lou Jiashu 
Published: January 2023

Abstract
It has been proven qualitatively that borehole tensor strainmeters (BTSM) could measure three surface-wave-induced strain components in the horizontal-normal plane. But strain waves are usually incident obliquely to borehole axis to induce not only horizontalnormal strain components but also the three other strain components in the plane of vertical normal, which are usually assumed to zero in conventional model of BTSM installed near the earth surface. Therefore quantitative kinematical-parameter measurement of strain waves of wave normal oblique to borehole axis by BTSM is still a challenging problem. In this paper, a scattering model of oblique-incidence seismic waves by an empty borehole is introduced to investigate instrumental responses of BTSM. Besides for the four gauges in conventional BTSM, three other gauges considering the influences of strain components in the plane of vertical normal are also introduced to build dynamic calibration matrix between instrumental and incident strains. It shows that within the effective bandwidth of BTSM, zero-frequency-gain for dynamic calibration matrix could be adopted approximately to build quantitative relation between instrumental strain waves of BTSM and oblique-incidence seismic strain waves. It is shown that the recommended gauge combinations could promise quantitative measurement of kinematic parameters of the incident strain P or S wave if high-resolution insitu calibration of BTSM has been conducted, which is important to the development of early warning system by borehole strainmeters.
Numerical and laboratory investigations of thermally induced fractures in rock salt
Authors: Körner Feline , Baumgärtel Lukas , Leuger Bastian 
Published: January 2023

Abstract
In order to widen the basis for the dimensioning of storage caverns in rock salt, some special attention must be paid to the temperature developments within the cavity during its operation. Passed numerical investigations have shown that a temperature change in the storage medium, such as natural gas or hydrogen, can cause stress differences of several MPa in the rock mass surrounding the cavern. If, as a result, the difference between horizontal and vertical stresses is increased, the rock being additionally loaded by a fluid pressure can fracture orthogonally to the lowest principal stress. The knowledge of temperature conditions and heat flows in the cavern surrounding salt rock are therefore of great importance. A wide variety of factors must be considered when investigating such mechanisms. The novel test facility at the Institute of Geotechnical Engineering of the Leibniz University Hannover is used to simulate the situation that occurs at the caverns edge when storage medium is withdrawn. This means, the cooling and the gas pressure inside the cavity are reconstructed on hollow cylindrical test samples made of rock salt from various locations to draw conclusions about the propagation of fractures and thus the safety of salt caverns under gas-loading. Before inducing any mechanical loads by means of a triaxial cell, a comprehensive investigation of the temperature field, resulting from the locally limited, artificially induced cooling of a sample is carried out with the new testing facility. While local temperatures in the sample drop by about 20 Kelvin, it is free to contract inwards, causing thermal stresses to decrease significantly. Therefore, the facility needs to be optimized and the testing scheme is changed. Instead of reducing stresses thermally, one of the mechanical loadings is diminished while the gas pressure inside the borehole is kept constant. As a result, the material visibly fractures while mechanical loadings are at a fully-compressive state.
Effect of layer orientation on behaviour of 3D-printed rock specimens in indirect tensile testing
Authors: Yang Weiyi , Huang Zili , Verma Rupesh , Nguyen Giang D , Tung Tran T , Karakus Murat 
Published: January 2023

Abstract
The mineralogical composition, texture and fracture of natural rocks can be complicated due to the inherent heterogeneity of geomechanical properties, making it challenging to understand their behaviour. Due to the intrinsic layer by layer manufacturing process, 3D printing technology enables to create rock-like materials and specimens with known and controllable inhomogeneity. In this study, disc specimens of a rock-like material are fabricated using 3D printing of cement mortar for testing to understand fabric orientation effect on fracture behaviour better. For the first time, a novel technique, named AUSBIT (Adelaide University Snap-back Indirect Tensile test), for Brazilian disc tests is applied for obtaining both strength and snap-back post-peak behaviour of the 3D printed rock-like materials. Adopting Digital Image Correlation (DIC) technique, in conjunction with the use of AUSBIT, allows obtaining full-field strains and their evolutions, showing strong effects of fabric orientation on strain distributions and both pre-and post-peak responses.
Simulation of wire mesh bearing capacity using the distinct element method (DEM)
Authors: Winderholler Rodrigo , Valli Jouni , Hakala Matti 
Published: January 2023

Abstract
The response of wire mesh sheets anchored with rock bolts to excavation surfaces has been investigated using the distinct-element method (DEM). Wire mesh reinforcement is a common practice both in mining and civil underground structures, providing passive support in case of unstable blocks. When the mesh is not embedded in a sprayed concrete layer, its design is usually performed based on statistical analyses of laboratory test results according to Eurocode. A laboratory-based approach can result in technical and economical limitations, especially when studying non-conventional or accidental design scenarios such as asymmetric loading or failure of the anchoring rock bolts. The simulation of the loading of a sheet of wire mesh has been performed with 3D-DEM software (PFC3D, Itasca) by discretizing the wire elements as connected particles which can simulate the progressive failure mechanism of the wire mesh observed in laboratory tests. The strength and deformability of the wire elements were calibrated to replicate laboratory results. Based on a limited amount of laboratory test data required for calibration, the investigated approach can complement laboratory results by providing an estimation of the expected strength and strain of the wire mesh reinforcement system under various loading scenarios.