Hard Conditions Research Articles

Exergaming in older adults: the effects of game characteristics on brain activity and physical activity.

Exergames are increasingly used in rehabilitation settings for older adults to train physical and cognitive abilities. To meet the potential that exergames hold, they need to be adapted to the individual abilities of the player and their training objectives. Therefore, it is important to know whether and how game characteristics affect their playing. The aim of this study is to investigate the effect of two different kinds of exergame (step game and balance game) played at two difficulty levels on brain activity and physical activity. Twenty-eight older independently living adults played two different exergames at two difficulty levels each. In addition, the same movements as during gaming (leaning sideways with feet in place and stepping sideways) were performed as reference movements. Brain activity was recorded using a 64-channel EEG system to assess brain activity, while physical activity was recorded using an accelerometer at the lower back and a heart rate sensor. Source-space analysis was applied to analyze the power spectral density in theta (4 Hz-7 Hz) and alpha-2 (10 Hz-12 Hz) frequency bands. Vector magnitude was applied to the acceleration data. Friedman ANOVA revealed significantly higher theta power for the exergaming conditions compared to the reference movement for both games. Alpha-2 power showed a more diverse pattern which might be attributed to task-specific conditions. Acceleration decreased significantly from the reference movement to the easy condition to the hard condition for both games. The results indicate that exergaming increases frontal theta activity irrespective of type of game or difficulty level, while physical activity decreases with increasing difficulty level. Heart rate was found to be an inappropriate measure in this population older adults. These findings contribute to understanding of how game characteristics affect physical and cognitive activity and consequently need to be taken into account when choosing appropriate games and game settings for exergame interventions.

캘더콧 수상작에 나타난 동물 형상화의 양상

This article aims to discuss animal-focused Caldecott winners in order to explore the way in which anthropocentric perspectives are projected onto animals, the animal wildness erupts through artificial coverings, and animals and humans meet in the wild. The act of feeding and helping animals is based on a highly human-centered setting that makes animals live and feel happy even in hard conditions, as depicted in Make Way for Ducklings, The Big Snow, and Song of the Swallows. The relationship between Genevieve and Madeline in Madeline’s Rescue shows that animals have risen to the status of friends living together, instead of being typified as inferior creatures. On the other hand, references to zoo tigers in Madeline’s Rescue lead to rethinking of the meaning of animals located in a separate space called a zoo, unlike pets, as in The Biggest Bear, May I Bring a Friend?, A Sick Day for Amos McGee, and Finding Winnie: The True Story of the World’s Most Famous Bear. Zoos are exposed to the fundamental problems implied by the observation that the zoo animals have been deprived of wildness. The wild energy of the animal as a “living creature” breaks through the cracks of the homopocentric layers no matter how hard the layers try to cover the energy, which is portrayed in The Three Pigs, Where the Wild Things Are, Jumanji, and Tuesday. A possible union of an animal and a human is hinted in The Girl Who Loved Wild Horses, but it is almost impossible to capture the scene with human language. Owl Moon and Wolf in the Snow demonstrate how hard it would be to try to reach the reality of the animal in the wild under the cover of human language. Not relying on any other human language than onomatopoeia, which translates the sounds of animals into symbols as they are heard, Owl Moon and Wolf in the Snow trace meaningful encounters between animals and humans in the wild.

Some Physiological Responses of Native Sheep Breeds to Environmental Conditions during Grazing in Natura 2000 Habitats

The calcareous xerothermic grasslands of the Festuco-Brometea class are among the most endangered Natura 2000 sites in Europe. The greatest threats include a lack of grazing, secondary succession, and invasive alien and expansive native species. The abandonment of such grasslands is caused by the low nutritional value of biomass, as well as by difficult habitat conditions. The aim of this study was to assess the physiological responses of native sheep breeds to hard environmental conditions when grazing in Natura 2000 habitats and to confirm the hypothesis that native sheep of the Świniarka and Uhruska breeds can be used to protect valuable natural habitats. The analysed grasslands were characterised by very difficult climatic and edaphic conditions and a low fodder value for sheep. Grazing in environmentally valuable areas, sometimes poor in fodder, did not adversely affect the welfare of grazed sheep. In both the Uhruska and Świniarka breeds, there were no indicators for heat or nutritional stress, but physiological changes were observed in the animals’ adaptation to new environmental conditions. Despite poor fodder positions, Świniarka sheep improved their condition and body weight. Fluctuations in indicators showing an adaptation process were also visible.

Tribological behaviour and wear mechanism of ADI with different hardness values

The tribological behaviour and wear mechanism of austempered ductile iron (ADI) with different hardness values were investigated. Results showed that the wear resistance of ADI was sensitive to hardness and service conditions. Under mild wear conditions, the low-hardness ADI sample exhibited high wear resistance because graphite was easy to transfer to the tribosurface and acted as a lubricant to reduce the friction coefficient. However, the high-hardness ADI sample was hard to deform plastically, which restricted the transfer of graphite from the matrix to the tribosurface. Under severe wear conditions, the plastic deformation of the low-hardness ADI sample gave rise to abrasive wear, which resulted in poor wear resistance. With the deterioration of wear conditions, the wear mechanism of ADI was transformed from micro-cutting wear to oxidative wear.

Moringa oleifera: A Sustainable Intervention To Address Malnutrition and Poverty in Khyber Pakhtunkhwa (KPK)- Pakistan

Rural inhabitants' lifestyles and health are greatly impacted by the recent growth in modernity,urbanization, and commercial farming as well as the loss of plant resources. Food should be consumed inthe era of incredible multi-functionality and objectivity not only to energize and feed us but also to fightagainst many illnesses and diseases and boost our immune systems. In rising nations like Pakistan, such astrategy is absolutely needed. Moringa oleifera is a very useful and versatile tree popularly named Suhanjnain Punjab, Pakistan. The Moringa tree is cultivated predominantly in semi-arid, subtropical, and tropicalenvironments. The M. oleifera belongs to the family Moringaceae is native to the sub-Himalayan areas ofPakistan, India, Bangladesh, and Afghanistan, and is grown internationally. In Pakistan, it is foundcommonly in southern Punjab and it is also considered the origin of Moringa plant. This plant has thepotential to thrive in any kind of soil and can endure extremely hard conditions. Moringa has remarkablenutritive value and it is a rich source of protein, vitamins (A & C), and micro-nutrients (Ca, K, Fe, etc.) thatare completely absent in the daily diet of the majority of the rural parts of KPK. Since 1998, the WHO haspushed Moringa as an alternative to imported food supplies to cure malnutrition in disadvantaged nations.Research has indicated that the dried leaves of Moringa contain 7 times more vitamin C than orange, 10times vitamin A than carrot, 17 times Ca than milk, 15 times K than bananas, 25 times Fe than spinach and9 times proteins than yogurt. In addition, it includes vitamin B-Complex, chrome, Cu, Mg, Mn, P and Zn.Its leaves are a great source of protein and may be exploited to combat malnutrition. In KPK, Moringaplanting and distribution have significant potential to promote farm income, improve nutrition, build upfood security, give a livelihood for rural people, stimulate rural development, and assist sustainable landcare.

Phonological and Semantic Specialization in 9- to 10-Year-Old Children During Auditory Word Processing.

One of the core features of brain maturation is functional specialization. Previous research has found that 7- to 8-year-old children start to specialize in both the temporal and frontal lobes. However, as children continue to develop their phonological and semantic skills rapidly until approximately 10 years old, it remained unclear whether any changes in specialization later in childhood would be detected. Thus, the goal of the current study was to examine phonological and semantic specialization in 9- to 10-year-old children during auditory word processing. Sixty-one children were included in the analysis. They were asked to perform a sound judgment task and a meaning judgment task, each with both hard and easy conditions to examine parametric effects. Consistent with previous results from 7- to 8-year-old children, direct task comparisons revealed language specialization in both the temporal and frontal lobes in 9- to 10-year-old children. Specifically, the left dorsal inferior frontal gyrus showed greater activation for the sound than the meaning task whereas the left middle temporal gyrus showed greater activation for the meaning than the sound task. Interestingly, in contrast to the previously reported finding that 7- to 8-year-old children primarily engage a general control region during the harder condition for both tasks, we showed that 9- to 10-year-old children recruited language-specific regions to process the more difficult task conditions. Specifically, the left superior temporal gyrus showed greater activation for the phonological parametric manipulation whereas the left ventral inferior frontal gyrus showed greater activation for the semantic parametric manipulation.

Experimental Investigation of Application Taguchi Method to Optimize Heat Treatment Parameters Using Nanofluids of AISI 52100 Steel

The present work describes a heat treatment procedure using nanofluids as quenchants for (AISI 52100 Steel) via the Taguchi method to optimize process parameters. The nanofluids have been prepared from nanoparticles (SiO2, SiC and Fe2O3) and base media consist of distilled water, toluene and ethylene glycol of volume concentrations of 0.02, 0.04 and 0.06 %. The present investigation considers hardness and wear rate as optimization criteria. The experimental variables that were selected for this study are: (austenitizing and tempering temperature), (type and volume fraction of nanoparticles) and (base media). They represent significant factors that influence on these optimization criteria. (AL18 orthogonal array), (analysis of variances (ANOVA)) and (signal/noise ratio (S/N)) were applied by means of (Minitab 18) software to examine the performance characteristics of the process parameters. The analysis of (S/N) ratio shows that the most significant parameters that give the optimum heat treatment conditions for hardness of the examined steel (AISI 52100) are: (austenitizing temperature of 800°C), (distilled water as a type of base media) and (tempering temperature of 180°C), in addition to (Fe2O3 as a nanoparticles type) and finally (nanoparticles volume fraction of 0.06%). In contrast, for the wear rate, they were: (austenitizing temperature of 800°C), type of base media (distilled water), tempering temperature of (180°C), and volume fraction of nanoparticles (0.06%) tempering. Finally, nanoparticles type (Fe2O3) is the most significant parameter for hardness and wear rate. ANOVA, exhibited that the austenitizing temperature has major effect on producing high values of hardness and wear rate for the AISI 52100 Steel.

Near Ultraviolet Photoresponse of a Silicon Carbide and Tantalum Boride Heterostructure

Silicon carbide (SiC) is widely used in abrasives, heating devices, light emitting diodes and high-power electronics, because of its unique physical-chemical properties including high hardness, high melting point, excellent thermal conductivity, and wide bandgap. In recent years, its color centers have also been used as potential sources of single photons. Given that borides and carbides are refractory materials, we decided to study a heterostructure formed by an n-doped silicon carbide substrate and a layer of tantalum monoboride (TaB) for near ultraviolet (UV) photodetection. It is shown that the addition of TaB creates a rectifying device that can handle currents higher than 300 mA, showing its potential for high-power optoelectronic devices. The detector also has a high responsivity of 2.9 A/W at the free-space wavelength of 405 nm and a fast frequency response of 610 kHz. The high performance of the detector is attributed to the high thermal and electrical conductivity, large bandgap of SiC, and its moderately close match in atomic arrangement with TaB. Such heterostructure offers a simple method to produce high-performance near UV photodetectors operating under hard conditions such as high power, high temperature and work in corrosive or oxidizing environments.

Exemplar-Guided Sedimentary Facies Modeling for Bridging Pattern Controllability Gap

Inferring subsurface structure from sparse log data is crucial for geology. Recently, deep-learning-based methods, which provide sufficient prior knowledge from training sets, have been proven to aid in sedimentary facies modeling. However, these methods suffer from suboptimal controllability of the geological model, i.e., the expected geological pattern fails to be specified, resulting in unpredictable generated geological structures. To bridge the gap, we propose a novel Exemplar-Guided Facies Modeling (EGFM) approach, which synthesizes a facies model from log data given a pattern exemplar. The key insight in EGFM is to decouple the content and pattern in the target model, where the content refers to the match with well data, and the pattern is the properties of geological structures, such as fluvial course and shape. On the basis of well data as the hard condition, a pattern exemplar is introduced as the reference model for geological realizations. In addition to preserving the commonalities of the holistic geological pattern (from the geological image set), such as structural connectivity, the pattern details of the geological realization can be tuned through pattern exemplars. Moreover, we introduce an adaptive feature fusion block (AFB) to adaptively fuse the content and pattern features for more natural results. Extensive experimental results on two river data sets demonstrate that our proposed EGFM for conditional facies modeling achieves satisfying visual quality and pattern controllability.

IMPROVED ADAPTIVE NONLINEAR CONTROL FOR VARIABLE SPEED WIND-TURBINE FED BY DIRECT MATRIX CONVERTER

This paper proposes a robust decoupling power algorithm based on a doubly fed induction generator (DFIG) for variable speed wind-turbine (WT). The DFIG rotor circuit is fed by the direct matrix converter (DMC), which presents several features such as no need to the dc-bus voltage, sinusoidal supply, rotor side waveforms, bidirectional power flow, and adjustable input power factor. The 18 bidirectional switches are controlled using the Venturini modulation technique. On the other hand, the DFIG stator circuit is connected directly to the grid. The nonlinear control strategy based on feedback linearization is applied to control the stator power (Ps and Qs) independently using the rotor quadrature and direct currents (irq and ird), which present the images of the previous stator powers. Some limitations appear in the power algorithm using the conventional pi controller, especially in power tracking, error, and quality. In this context, the model reference adaptive controller (MRAC) presents an alternative solution, a robust and efficient controller proposed instead of the pi controllers to control stator powers. Finally, the simulation results confirm that the proposed algorithm could work under hard conditions and demonstrate that the wind energy conversion system (WECS) provides enhanced dynamic responses in transient and steady states and good power quality delivered to the grid.

Первые женщины-врачи на службе Саратовского земства (конец XIX – начало XX в.)

Introduction. The gender aspects of modern medicine determine the research interest in the activities of the first female doctors in Russia. In contrast to private practice, the work of doctors in the zemstvo played an important social role. Therefore, the object of this study is the activities of the first female doctors in the service of the Saratov zemstvo. Methods and materials. The source base of the study was the materials of the zemstvo periodicals and office-work documentation (journals of zemstvo meetings, reports of councils, protocols of medical congresses). The historical-systemic method made it possible to consider the professional activities of the first female doctors of the Saratov zemstvo in the context of the formation of the system of women’s medical education in the Russian Empire. With the help of the historical-comparative method, the general features of the professional activity of V.I. Bukhovtseva, A.I. Sukhodeeva, and E.A. Kharizomenova were defined. Analysis and results. The authors established the first female doctors appeared in the service of the Saratov zemstvo at the turn of the 1880–1890s. The entry of women into the zemstvo service was hampered by restrictions on the independent medical practice, the termination of medical courses in 1887, and hard working conditions in the Russian provinces. However, the activities of V.I. Bukhovtseva, A.I. Sukhodeeva and E.A. Kharizomenova at the Saratov zemstvo demonstrated the organizational and research abilities of the first female doctors, their awareness of the medical and social problems of the Russian hinterland, and active participation in sanitary and educational work. Restoration and development of higher medical education for women at the turn of the 1890–1900s became the main factor in the increase in the number of female doctors in the zemstvo service, the expansion of their professional competencies, and the increased role in the development of the health care system. Authors’ contributions. The study of zemstvo office documentation and periodicals containing information about the activities of the first female doctors in the Saratov province was carried out by Candidate of Historical Sciences, associate professor O.S. Kitsenko. Information about the number and place of service of female doctors in the Russian medical lists of 1883–1916 analyzed by the Candidate of Philosophical Sciences, associate professor R.N. Kitsenko.

Experimental and Simulation Study on the Hard Rock–Breaking Characteristics of Disk Cutter under the Water Jet Precutting Kerf

The effect of water jet kerf depth (H) and cut spacing (S) on the rock-breaking performance of a disc cutter under water jet precutting kerf was investigated through a full-scale linear cutting test and numerical analysis with a discrete element method (DEM). Rock-breaking force, rock chip, and rock-breaking efficiency are used to evaluate the rock-breaking performance. The rock-breaking experimental results show that the rock failure patterns are closely related to H and S, and distinct rock failure patterns are shown for the different rock-breaking parameters. In addition, this study reveals the variation law of rock-breaking force and specific energy (SE) consumption with H and S. The difference in crack expansion between rock-breaking under conventional and precutting kerf conditions was compared with numerical simulations. The lateral cracks tend to expand toward the bottom of the precutting kerf and are more prone to produce large-sized rock chips in the precutting kerf condition. In addition, the increased H promotes the expansion of the vertical and lateral cracks, which resulted in different rock failure patterns. Therefore, the numerical, and experimental results show that the rock-breaking of the disc cutter under the precutting kerf conditions is promising, which significantly improves the rock-breaking performance of the disc cutter in hard rock conditions.

Physics-based models, surrogate models and experimental assessment of the vehicle–bridge interaction in braking conditions

The dynamics of roadway bridges crossed by vehicles moving at variable speed has attracted far less attention than that generated by vehicles travelling at constant velocity. Consequently, the role of some parameters and the combination thereof, as well as influence and accuracy of the modelling strategies, are not fully understood yet. Therefore, a large statistical analysis is performed in the present study to provide novel insights into the dynamic vehicle–bridge interaction (VBI) in braking conditions. To this end, an existing mid-span prestressed concrete bridge is selected as case study. First, several numerical simulations are performed considering alternative vehicle models (i.e., single and two degrees-of-freedom models) and different braking scenarios (i.e., soft and hard braking conditions, with both stationary and nonstationary road roughness models in case of soft braking). The statistical appraisal of the obtained results unfolds some effects of the dynamic VBI modelling in braking conditions that have not been reported in previous studies. Additionally, the use of machine learning techniques is explored for the first time to develop surrogate models able to predict the effect of the dynamic VBI in braking conditions efficiently. These surrogate models are then employed to obtain the fragility curve for the selected prestressed concrete bridge, where the attainment of the decompression moment is considered as relevant limit state. Whilst the derivation of the fragility curve using numerical simulations turned out to be almost unpractical using standard computational resources, the proposed approach that exploits surrogate models carried out via machine learning techniques was demonstrated accurate despite the dramatic reduction of the total elaboration time. Finally, the accuracy of the numerical (physics-based and surrogate) models is evaluated on a statistical basis through comparisons with experimental data.

Estimate of Responses of Multistoried Building under Earthquake Ground Motion to Prevent Failure

Seismic microzonation is defined as the process of subdividing a potential seismic or earthquake-prone area into zones with respect to some geological and geophysical characteristics of the sites such as ground shaking, liquefaction susceptibility, landslide, and rock fall hazard, earthquake-related flooding, etc. Very often, the seismic data are used from existing ground motion data that are related to other geographical regions and thus leads to unrealistic predictions. In this analysis, normalization of the available earthquake data is carried out for a better realistic prediction of building response. An extensive study is carried out in this work that involves two major types of buildings, microzones, and soil conditions. Fixed base, hard, medium, and soft soil have been considered for this analysis. The effect of actual and normalized ground motion for specific microzones having plan asymmetric and symmetric structures is not yet studied in prior research. The analysis has been done by finite element-based software. The present study makes an effort to determine the fundamental responses of plan asymmetric building in different kinds of soil in certain microzones. Maximum shear forces and bending moment have been seen in hard soil base conditions among all other supports. Responses of microzone II and actual ground motion are almost the same in dynamic analysis.

Seismic response of column supported tanks considering uplift effect and soil‐structure interaction

AbstractIn this paper, the seismic responses of column supported tanks under horizontal earthquake are obtained by finite element method. Two types of structures are discussed including the anchored tank with columns fixed on the ground and the resilient tank whose columns can uplift. The uplift effect is realized by the contact algorithm to allow the column move upwards in a vertical direction and the soil‐structure interaction (SSI) is considered by equivalent soil springs. Different soil types and hard ground condition are adopted to study SSI effect on natural frequencies of tanks and seismic responses of the anchored tank, as well as coupling effect (both uplift and SSI effects) on seismic responses of the resilient tank. The structural displacement and acceleration, the stress of tank walls and columns, the base shear and the overturning moment, the uplift displacement of columns are discussed. The results of tanks in different conditions are compared with each other, which show that SSI has a significant impact on seismic responses of column supported tanks. As the stiffness of soil decreases, the tank has larger displacement, smaller natural frequency, and stress level of structural members especially when it is sited on softer soil type. Compared to the anchored tank, due to the combination of both uplift effect and foundation deformation, the resilient tank has smaller displacement to prevent its overall collapse and lower responses such as the base shear and the overturning moment. The resilient tank has better seismic performances regardless of soil conditions.

Understanding the initial use stage of cement mortar lining in drinking water distribution systems: Silicon and aluminum as stability indicators

The cement mortar lining (CML) of commonly used ductile iron pipes can severely deteriorate the drinking water quality at the initial stage of use, but the behavioral characteristics of different elements release from the CML in this stage is still unclear. In this study, dynamic immersion experiments with new cement mortar lined ductile iron pipe reactors were conducted under different feed water hardness and alkalinity conditions. The results showed that the release of alkaline substances from the CML at the initial stage of use could strongly influence the pH of water, which consequently greatly impacted the release/precipitation behaviors of calcium, aluminum and silicon. The pH and aluminum concentration of the effluent water could reach 11.5 and 700 µg/L within 24 hr of hydraulic retention time, respectively, under conditions of relatively lower hardness and alkalinity. Due to the pH elevation, calcium carbonate precipitation could occur even at much lower feed water alkalinity. Whereas the aluminum and silicon could keep release from the CML in soluble form at different hardness and alkalinity levels, and their release rate depended on the amount of calcium carbonate precipitation. Thus, aluminum and silicon were more suitable as indicators of the corrosion intensity at the initial stage of CML use rather than the traditional calcium carbonate precipitation potential. Appropriate feed water hardness and alkalinity levels for mitigating the initial intense corrosion of CML were proposed: hardness > 40 mg/L (CaCO3), alkalinity > 100 mg/L (CaCO3).

An integrated vision control system for the evaluation of the shape-dimensional accuracy and quality of valve forgings used in motor truck engines

The study refers to a system of vision control concerning the dimension and shape accuracy as well as quality of valve forgings assigned for motor truck engines produced in a two-operation process of forging in closed dies. The performed investigations included a complex review of the solutions regarding various methods of measuring the selected geometrical features or other parameters for different forged elements – forgings during the production process. The conducted literature analysis has showed that, due to the hard operation conditions of the forging processes, measurements of this type are very difficult and the elaborated measurement methods are often dedicated to specific forgings and forging processes. On this basis, a proprietary measuring method was developed based on an adapted industrial laser profilometer installed on a proprietary measurement station, making it possible to conduct measurements under industrial conditions, owing to the application of the elaborated construction enabling automatic collection and manipulation of the scanned forgings directly on the production line. The built system makes it possible to measure the 2 key geometrical characteristics of an exhaustion valve forging: feature A – the diameter of the outer valve head, feature B - the calotte's depth, as well as, additionally, feature C – the surface quality in the form of detection of the most frequent defect: radial scratches (cavities) on the upper surface of the disc-like forging. In the first place, measurements under laboratorial conditions were made, which were then repeated under industrial production conditions in order to determine the influence of operating conditions (like: vibrations, temperature, etc.). Next, a final verification of the constructed system was carried out for forgings measured under strictly industrial conditions (measurement of forgings collected directly from the process). The obtained results of the elaborated measurement method showed high accuracy of the proposed solution, as, compared to the results under laboratorial conditions vs. industry, the error in the case of the 2200th forging, for feature A, equalled 0.35 mm, and for feature B (for 2200th and 100th forging), it was about 0.02 mm. Further studies will focus on be the possibility of measuring the profile of the disc's transition into the leg as well as detection of defects on the forging's leg in the form of longitudinal scratches.

Generating Random SAT Instances: Multiple Solutions could be Predefined and Deeply Hidden

The generation of SAT instances is an important issue in computer science, and it is useful for researchers to verify the effectiveness of SAT solvers. Addressing this issue could inspire researchers to propose new search strategies. SAT problems exist in various real-world applications, some of which have more than one solution. However, although several algorithms for generating random SAT instances have been proposed, few can be used to generate hard instances that have multiple predefined solutions. In this paper, we propose the KHidden-M algorithm to generate SAT instances with multiple predefined solutions that could be hard to solve by the local search strategy when the number of predefined solutions is small enough and the Hamming distance between them is not less than half of the solution length. Specifically, first, we generate an SAT instance that is satisfied by all of the predefined solutions. Next, if the generated SAT instance does not satisfy the hardness condition, then a strategy will be conducted to adjust clauses through multiple iterations to improve the hardness of the whole instance. We propose three strategies to generate the SAT instance in the first part. The first strategy is called the random strategy, which randomly generates clauses that are satisfied by all of the predefined solutions. The other two strategies are called the estimating strategy and greedy strategy, and using them, we attempt to generate an instance that directly satisfies or is closer to the hardness condition for the local search strategy. We employ two SAT solvers (i.e., WalkSAT and Kissat) to investigate the hardness of the SAT instances generated by our algorithm in the experiments. The experimental results show the effectiveness of the random, estimating and greedy strategies. Compared to the state-of-the-art algorithm for generating SAT instances with predefined solutions, namely, M-hidden, our algorithm could be more effective in generating hard SAT instances.

The micro-RWELL detector for the phase-2 upgrade of the LHCb muon system

The micro-RWELL detector (μ-RWELL) is a single amplification stage resistive Micro Pattern Gaseous Detector (MPGD), based on a copper-clad polyimide foil patterned with a micro-well matrix coupled with the readout PCB through a DLC resistive film (10÷100MΩ/□). For the phase-2 upgrade of the LHCb experiment, proposed for the LHC Run-5, the excellent performance of the current muon detector will need to be maintained at 40 times the pile-up level experienced during Run-2. Requirements are challenging for the innermost regions of the muon stations: the detectors should exhibit a rate capability up to 1MHz/cm2 and they are supposed to integrate a charge up to ∼1C/cm2. In this framework an intense optimization program of the micro-RWELL technology has been launched in the last year, together with a technology transfer to the industry operating in the PCB field. In order to fulfill the requirements, a new layout of the detector with a very dense current evacuation grid of the DLC has been designed. The detector, co-produced by the CERN-EP-DT-MPT Workshop, lead by one of the authors, and the ELTOS Company, has been characterized in terms of rate capability exploiting a high intensity X-ray Philips 2217/20 gun with a spot size (10÷50mm diameter) larger than the DLC grounding-pitch. A rate capability exceeding 10MHz/cm2 has been achieved, in agreement with previous results obtained with m.i.p. at the Paul Scherrer Institute (PSI) in Villigen (CH). A long term stability test is in progress: a charge of about 5mC/cm2 has been integrated over a period of about 16 days. The test will continue, in harder conditions (larger gain and X-ray flux), with the goal to integrate about 1C/cm2 in one year, while a slice test of the detector is under preparation.

Numerical and Experimental Study of a Lattice Structure for Orthopedic Applications.

Prosthetic reconstructions provide anatomical reconstruction to replace bones and joints. However, these operations have a high number of short- and long-term complications. One of the main problems in surgery is that the implant remains in the body after the operation. The solution to this problem is to use biomaterial for the implant, but biomaterial does not have the required strength characteristics. The implant must also have a mesh-like structure so that the bone can grow into the implant. The additive manufacturing process is ideal for the production of such a structure. The study deals with the correlation between different prosthetic structures, namely, the relationship between geometry, mechanical properties and biological additivity. The main challenge is to design an endoprosthesis that will mimic the geometric structure of bone and also meet the conditions of strength, hardness and stiffness. In order to match the above factors, it is necessary to develop appropriate algorithms. The main objective of this study is to augment the algorithm to ensure minimum structural weight without changing the strength characteristics of the lattice endoprosthesis of long bones. The iterative augmentation process of the algorithm was implemented by removing low-loaded ribs. A low-loaded rib is a rib with a maximum stress that is less than the threshold stress. Values within the range (10, 13, 15, 16, 17, 18, 19 and 20 MPa) were taken as the threshold stress. The supplement to the algorithm was applied to the initial structure and the designed structure at threshold stresses σf = 10, 13, 15, 16, 17, 18, 19 and 20 MPa. A Pareto diagram for maximum stress and the number of ribs is plotted for all cases of the design: original, engineered and lightened structures. The most optimal was the designed "lightweight" structure under the condition σf = 17 MPa. The maximum stress was 147.48 MPa, and the number of ribs was 741. Specimens were manufactured using additive manufacturing and then tested for four-point bending.