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The development of power grid infrastructure and increasingly stringent environmental regulations have intensified work, carried out by researchers and electrical equipment manufacturers, to develop innovative gas-insulated, environmentally neutral devices. The emergence of new designs of circuit breakers and disconnectors, in which the resulting electric arc is extinguished in a vacuum environment, requires the development of appropriate techniques for diagnosing the chambers responsible for the dielectric parameters of the device. The following article presents an overview of the directions of development of diagnostic methods for medium-voltage vacuum switching equipment, which can potentially be used to develop a real-time pressure monitoring system that can be applied to vacuum switching equipment used in electrical infrastructure. [ABSTRACT FROM AUTHOR]

The effects of topical negative pressure therapy (TNP) have been a subject of research for many years. In this study, we investigated new imaging devices to detect clinical changes that TNP causes on healthy tissue and identified differences in microcirculation created by different pressure levels. We used near-infrared spectroscopy (NIS), thermography, and a vein illuminator to measure the differences in oxygen saturation, tissue temperature, and vein pattern. A control group (−125 mmHg) and three comparison groups with only TNP dressing (Group 1), −25 mmHg (Group 2), and −175 mmHg (Group 3) were established. Thirty minutes of TNP on intact skin was followed by 30 min of resting. A total of 24 participants were measured by all imaging devices at predetermined time points. Oxygen saturation and skin temperature increased by 8.07% and 1.67 °C for the control group, 4.00% and 1.65 °C for Group 2, and 8.45% and 1.68 °C for Group 3. Group 1 showed a slight increase in oxygen saturation and a 2.7 °C increase in skin temperature. Over the 30 min following removal of TNP, oxygen saturation and temperature decreased gradually for all groups. The vein illuminator did not show significant differences in the venous pattern or flow. Our study showed that higher negative pressure values resulted in higher oxygen saturation and higher tissue temperature. [ABSTRACT FROM AUTHOR]

Route choice significantly impacts pedestrian evacuation efficiency. Previous studies have mainly focused on environmental or pedestrian conditions in single enclosed spaces, with limited consideration for the effects of successive paths, including both the current paths and subsequent paths beyond the room where pedestrians are located. In this study, we propose a new experimental setup with multiple subsequent paths. We carried out a series of single-person experiments to investigate the effect of different pressure levels on pedestrian route choice in multiple scenarios with different subsequent paths. The results indicate that path length is an important factor for the single person route choice, and the greater the length difference between alternative paths, the higher the proportion of pedestrians choosing the shorter path, reaching up to 100 %. Participants seem to have a short-term oriented behavior, when the total path length is the same, over 60 % of participants chose the shorter current path in all scenarios, and with a 21.67 % higher selection rate observed in high-pressure scenarios compared to low-pressure scenarios. The results of the logit regression analysis also significantly indicate the impact of pressure on pedestrian route choice, and the length of the current path has a greater influence on route choice than the length of the subsequent path. These results provide new evidence for future evacuation design and management in enclosed spaces. [ABSTRACT FROM AUTHOR]

The development of power grid infrastructure and increasingly stringent environmental regulations have intensified work, carried out by researchers and electrical equipment manufacturers, to develop innovative gas-insulated, environmentally neutral devices. The emergence of new designs of circuit breakers and disconnectors, in which the resulting electric arc is extinguished in a vacuum environment, requires the development of appropriate techniques for diagnosing the chambers responsible for the dielectric parameters of the device. The following article presents an overview of the directions of development of diagnostic methods for medium-voltage vacuum switching equipment, which can potentially be used to develop a real-time pressure monitoring system that can be applied to vacuum switching equipment used in electrical infrastructure.

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In order to explore the variation rule of water noise with flow momentum under law Froude number，the influence of water flow mo­mentum on the sound pressure level in the stilling pool was analyzed by means of physical model experiment.The results show that the sound pressure level increases with the increase of water flow momentum，and there is a linear positive correlation between them. SPSS is used to obtain the fitting curve of water flow momentum and sound pressure level at the inlet of the stilling basin. According to the principle of energy conservation，the reduced kinetic energy is converted into heat and dissipated， and some are dissipated in the form of oscillatory energy， which includes the water noise heard by the human ear. The prediction of water noise of fitting curve provides theoretical basis， which shows that curve fitting has practical significance. [ABSTRACT FROM AUTHOR]

Mean monthly precipitable water values from twenty seven state capitals and Federal Capital Territory, Abuja are determined using a ten year monthly meteorological parameter- average surface temperature. The results are then presented on annual average precipitable water map. The map shows that location with high topography has lowest value of precipitable water while location with plain terrain has highest value of precipitable water

Through the evaluation of some etiopathogenic risk factors one can anticipate the evaluation of some fractures towards Compartmental Syndrome (CS) and then their diagnosis in early stage, when the symptomatology is still unconvincing and the treatment reduces the risk of ischemia lesions. Based both on some prospective observations, using a group of shank fractures, and also on the clinical facts of constituted CS, there were made correlations, statistically reported in the case of some etiopathogenic risk factors represented by the fracture localization and its characteristics, traumatic mechanisms, soft tissue quality and polytraumatism, having an objective common denominator, the compartmental pressure level measured directly. The authors propose an etiopathogenic risk score of CS for the fractures reaching the pressure level of 20-30mmHg, recommending the pressional and clinical monitoring for a score of minimum 10 points. These fractures have a certain risk of CS. [ABSTRACT FROM AUTHOR]

The purpose of the present paper is to investigate the effect of elastic deformation of bearing liner on the acoustic behavior of oil lubricated journal bearings. Analysis is performed for hydrodynamic(HD) and elasto-hydrodynamic (EHD) lubrications. Dynamic behavior and acoustical properties are investigated through an analysis of pressure fluctuation calculated from the Reynolds equation governing the flow in the clearance space of the journal bearing. This is solved numerically using the finite difference method with the successive over relaxation technique. In elasto-hydrodynamic lubrication, the finite element method with in iteration scheme is adopted to solve both Reynolds equation and the three-dimensional elasticity equation representing the displacement field in the bearing shell. The results show that the sound pressure level of the bearing is markedly influenced by the flexibility of the bearing liner, the viscosity of lubricant and the load applied to journal. HD analysis shows that the journal centre’s orbit, from a disturbed position, converges to the static equilibrium position faster than EHD lubrication. The results of the present paper could aid in the design of low-noise rotor-bearing systems supported by oil lubricated journal bearings. [ABSTRACT FROM AUTHOR]

The design of small-sized single pass boilers is usually based on the construction code for small-sized boilers, in Japan. Design methods in this construction code and other country codes have not been clearly defined, although most of small-sized boiler's headers are constructed from two concentric circular shells and cover plates. Therefore, Finite Element Analysis (FEA) with a PC and measurement by strain gauges are mainly used in strength design of these boilers. In this study, a T type welded joint of SS400 was adopted for the header of small-sized single pass boilers. Fatigue testing and FEA was carried out. The fatigue limit was greater for base metal than for weldment. For the weldment, the S-N curve decreased with decreasing ρ value. The stress concentration at the toe was evaluated by the FEA. S-N curves for different toe curvature radii were re-drawn using maximum elastic stress, Ktσmax. Crack initiation occurred in the vicinity of the toe. Several small cracks were observed on the surface of T type welded joint fatigue specimen at N/Nf=0.42. These cracks coalesced together at a crack length of 10mm. Fatigue crack growth rate lineally increased with increasing (crack length)1/2. [ABSTRACT FROM AUTHOR]