Role of Geologists During Tunnel Construction and Face Mapping to Decide the Required Tunnel Support

The stability of underground structures is an important aspect during design, construction and execution Phase. Depending on the geotechnical conditions and influencing factors, different failure modes during execution mode can be expected, and depending on the potential failure modes, boundary conditions and specific construction measures to ensure stability have to be chosen. The most important is developing a realistic estimate of the expected ground conditions and their potential behaviour/failure modes as a result of the excavation. The variability of the geological conditions including local ground structure, ground parameters, stress and ground water conditions requires that a consistent and specific procedure is used. The other is to design an economic and safe excavation and support method for the determined ground behaviours. The discussion of role of geologists during design stage is beyond the scope of the present study. The main objective of this study is to present the role of geologists during the construction stage. Keywords: Geologist, Stress, Behaviour, RMR, Q Value, RQD, Rock Mass

Perception of stress in cats by German cat owners and influencing factors regarding veterinary care

Objectives Visiting the veterinarian is generally perceived as a stressful situation for cats. Previous studies have shown that the perception of stress may influence cats’ healthcare. In order to minimise stress in cats during the veterinary consultation, feline-friendly handling has gained importance and is increasingly being used. The aim of this study was to find out whether cats experience stress during a visit to the veterinarian (and, if so, to what extent), and which factors influence the perception of stress and whether feline-friendly handling techniques have an impact. Methods An online survey was conducted among German cat owners. In total, 889 questionnaires were evaluated. The results were analysed with binary logistic regression and a χ² test. A principal component analysis was used to detect the main influencing factors on the perception of stress. Results Most of the cats (88.7%, n = 732/825) were perceived as stressed during a veterinary consultation, while only about half of the owners (50.8%, n = 419/824) stated that they felt stressed themselves. The cat owners (n = 819) who perceived visiting the veterinarian as a stressful situation also described their cat as stressed significantly more often compared with owners who did not feel stressed (χ² = 101.113, P <0.001). The probability that owners experienced stress themselves was significantly increased if they perceived their cat to be stressed too (odds ratio 0.073, 95% confidence interval 0.016–0.328). One factor that influenced whether an owner was stressed was the stress behaviour of their cat (P <0.001). Furthermore a feline-friendly demeanour by the veterinarian led to less stress in the owners (P <0.001). Conclusions and relevance The owner’s stress influences the perception of their cat’s stress. By adhering to feline-friendly handling guidelines, veterinarians can reduce owner stress associated with veterinary visits, thereby promoting optimal veterinary care and health for their feline patients.

Tribological Stress Behaviour of Cast Iron without and with Surface Treatment under Concentrated Contact Load*

The graphite inclusions typical of grey solidified cast iron materials reduce the load-bearing capacity under locally concentrated pressure and simultaneous sliding stress. Surface treatment processes such as nitriding and electron beam remelting are known to improve the local stress behaviour. In this paper, the effects of the above-mentioned individual processes and their combination on the tribological stress behaviour of ferritic and pearlitic cast irons with different graphite morphologies are discussed. The results obtained in the model wear test ball-plate show that the specific wear coefficient of the investigated cast irons with different graphite morphology can already be reduced by at least one order of magnitude by an approx. 0.5–0.9 mm thick remelted surface layer with a surface hardness of 650–750 HV1. This treatment eliminates the graphite and produces ledeburitic carbides instead. The potential of an additional nitriding treatment depends on the parameters used, i. e. the nitrided layer thickness produced as well as the phase composition and the pore fraction of the compound layer. Based on stress calculations, the experimentally determined main influences such as the coefficient of friction, the pore fraction in the compound layer and the magnitude of the Hertzian pressure on the contact stress could essentially be confirmed.

Stress and Strain Distribution in the Upsetting Process

Numerical simulation of metal flow behaviour was studied using DeformTM3D software. The simulation process was done on X20 steel taken from the software database at 1073-1273K temperature, 10mm/s die speed, and 67% height reduction. From the simulation results, forging load, damage, and stress/strain distributions were obtained. The results show that the forging load increased with a decrease in temperature or decreased with an increase in temperature. The maximum damage values increased as the temperature increased. The obtained maximum damage values were 0.42 (1073K), 0.43 (1173K), and 0.45 (1273K). The damage distribution was inhomogeneous in the deformed cylinder. The stress/strain distributions were inhomogeneous in the deformed cylinder. The location of the maximum strain was at the centre of the deformed cylinder while the maximum stress occurred at the die-cylinder contact surfaces. The study showed that flow stress behaviour can be predicted using finite element method. This shows the feasibility of applying the finite element analysis to analyse the forging process.

IDENTIFICATION OF OCCUPATIONAL STRESSORS AMONGST RADIOGRAPHERS

Purpose: The aim of this research is to defi ne stress and correlated factors and identify which stressors are present among radiographers in relation to their workplace. Methods: A total of 450 radiographers received a questionnaire that covers a variety of workplace stressors, which conditions aff ect stress, how frequently radiographers notice stress and to what extent they use coping mechanisms. The online survey was available on the website 1ka and the results were analysed using the IBM SPSS program. Results: A total of 236 radiographers completed the survey (52.4% response rate). Interpersonal relations and management staff cause the highest level of stress, while the most important stressor is a conflict with a supervisor (3.38). Radiographers who work in a field of radiotherapy perceive the most stress. There is no difference between a healthcare activity in relation to levels of perceived stress. We could not identify any statistically significant differences in perceived stress in relation to gender or age (p?0.05). Radiographers who asses their relationship with co-workers and supervisors as good perceive lower levels of stress. Additionally, the same results are present with radiographers who are satisfied because they work in a multidisciplinary team (p?0.05). Teaching new staff has a positive correlation with occupational stress development. Unnecessary radiological procedures, along with unclear roles, have no effect on the development of stress behaviour (p>0.05). However, a conflict between roles has a major association (p?0.05) with stress occurrence. The most frequent methods for reducing symptoms of stress are caring for one’s health and physical appearance (3.77). It proved that communication with patients and duty work (p<0.05) represent significant elements of the workload. Most radiographers think that physical conditions in the workplace could be improved. Discussion and conclusion: The results show that radiographers notice a variety of stressors in their workplace. The most important are related to interpersonal relations. Further research should include analysis of stress within particular fields of radiography that would help to explain occupational stress.

Stress behaviour across human tooth by temperature gradient resulting of laser irradiation

The authors report the simulation of temperature distribution and thermally induced stress in the premolar tooth under ND-YAG pulsed laser beam. The Three-Phase-Lag (TPL) non-Fourier model is proposed to describe the heat conduction in the human tooth with nonhomogeneous inner structures. A premolar tooth comprising enamel, dentin, and pulp with real shapes and thicknesses are considered and a numerical method of finite difference was adopted to solve the time-dependent TPL bio-heat transfer, strain and stress equations. The surface heating scheme is applied for simulation of laser therapy. The aim of this laser therapy is that the temperature of pulp reaches to 47oC. The results are achieved as a function of laser heat flux showed when laser beam is irradiated downward (from the top of the tooth), the temperature and thermally induced stress increase as a function of time. The temperature increment is high on the top layers of tooth that is a result of strong absorption of beams by enamel. The thermal stress and strain in the enamel and dentin layers are more than the pulp layer that is a result of weak thermal expansion of them proportional to the pulp layer.