Safety Comfort Research Articles

EVALUATION OF WHEEL LOAD FLUCTUATIONS.

Unevenness of the road surface impairs ride comfort and vehicle safety. This paper quantifies the influence of wheel load fluctuations which occur in certain circumstances on vehicle handling. The reason for this influence is that wheel load fluctuations produce changes in tyre properties: the average cornering forces decrease and dynamic lateral force fluctuations are produced. In respect to handling, this results in changes to the steering tendency, stability and dynamic response. In addition, it also produces variations from the course. For simulation, a dynamic high frequency tyre model and a non–linear vehicle model are developed. In step two, a quarter vehicle illustrates the main tyre properties changed by wheel load fluctuations. In a third step, the effects of the changed tyre properties on driving behaviour in linear range are discussed by means of a linear single track model. In a final step, the influences of the wheel load fluctuations on driving behaviour into the limit range are shown. In addition, results of measurements are presented and important vehicle parameters are analysed. It is shown that even high fluctuations in wheel load need not significantly impair vehicle safety. This is achieved by evaluating wheel loads separately from axle or body resonance. A proposal for reducing the conflicting aims between vehicle safety and ride comfort is presented.

In a land of death and diamonds

The Lassa Ward is a real account of a US medical student’s time in a country ravaged by war and poverty. Ross Donaldson, a 20 something medical student leaves behind the comfort and relative safety of the United States and travels to Sierra Leone. While working in a remote hospital he comes face to face with the deadly viral haemorrhagic disease Lassa fever. The Lassa Ward offers a glimpse of the struggles faced by the people of this war stricken country. In the summer of 2003 …

Problems of tractor design evolution

The article presents the author's thoughts on the most promising areas of evolution of tractor designs, based on the analysis of the impact of new design solutions on consumer properties of tractors. These properties are mainly determined by productivity, cost-effective use of resources, comfort and operational safety, and environmental properties.

Novel Electromyographic Monitoring Technique for Prevention of Right Phrenic Nerve Palsy During Cryoballoon Ablation

Right phrenic nerve palsy (PNP) is the most frequent complication of cryoballoon ablation. Diaphragmatic electromyography can predict PNP with a comfortable safety margin. Our goal was to evaluate the feasibility, efficacy, and safety of electromyography-guided PN monitoring using a novel hepatic vein approach for prevention of PNP. This study includes 57 patients (47 males) indicated for cryoballoon ablation for treatment of atrial fibrillation. During right superior pulmonary vein ablation, the PN was paced at 60 beats per minute and diaphragmatic compound motor action potential (CMAP) amplitude was recorded via a quadripolar catheter positioned in a subdiaphragmatic hepatic vein. If a 30% drop in CMAP amplitude was observed, ablation was discontinued with forced deflation. Reliable recording of CMAP before ablation was feasible in 50 of 57 patients (88%). In 7 patients (12%), stable PN pacing could not be achieved. In 44 of 50 patients, CMAP amplitude remained constant during cryoapplication. The mean value of CMAP amplitude was 639.7±240.5 µV; mean variation was 13±4.3%. In 6 of 50 patients (12%) including 5 treated with a 23-mm cryoballoon and 1 with a 28-mm cryoballoon, the 30% reduction cutoff was reached and cryoablation was discontinued. Recovery of CMAP amplitude after discontinuing cryoablation took <60 seconds in all cases. No PNP or complication related to PN monitoring occurred. Recording of diaphragmatic CMAP using a catheter positioned in a subdiaphragmatic hepatic vein seems feasible during cryoballoon ablation. Electromyography-guided PN monitoring seems safe and potentially helpful for prevention of PNP.

Percutaneous Tracheostomy at the Bedside

We have developed a set of routines and practices in the course of performing a large series (n = 70) of percutaneous dilational tracheostomy (PDT). The 13 tips discussed in this review fall into 4 categories. System factors that facilitate training, patient safety, and avoidance of crises including the use of appropriate personnel, importance of timing, use of premedication, and the utility and content of a preprocedure briefing. Suggestions to prevent loss of the airway include tips on airway assessment, preparation of airway equipment, and use of exchange catheter techniques. Strategies to avoid and manage both microvascular and large-vessel bleeding are discussed. We also discuss the management of common postprocedure problems including tracheostomy tube obstruction, malposition requiring tube exchange or replacement, and air leak. The practical considerations for successful execution of PDT involve common sense, thorough planning, and structured approaches to prevent adverse effects if the procedure does not go as smoothly as expected. These strategies will aid anesthesiologists and intensivists in improving their comfort level, safety, and competence in performing this beside procedure.

Alternative friction models for braking train dynamics

Braking dynamics plays an essential role in ensuring the comfort and running safety of trains. Due to the complexity of the phenomena involved and the presence of dry friction, studies have been carried out by numerical methods using smoothening. Based on the non-smooth dynamics framework, in the present paper, an efficient and comprehensive alternative model is defined. Set-valued friction of Coulomb's law type is accounted for and motion equations are formulated as a differential inclusion. Some of the fundamental issues of contact dynamics are briefly reviewed. Static friction forces which arise in buffers are computed in a very intuitive and efficient manner, using an original method involving generalised inverses of matrices. The corresponding algorithm is described. Numerical integration is done by an event-driven algorithm. Indeterminate system configurations can be appropriately handled. The number of vehicles on which tests have been carried out ranged from 5 to 50. Comparison with the smoothening method reveals significant differences. Computational efficiency is dramatically improved. Computation speed can rise by a few orders of magnitude. Specific phenomena such as stick–slip or persistent longitudinal forces can be evidenced. Computed values of the system states differ substantially. In addition to this, any wagon connection model can be embedded.

Methods of Dynamic Tire Pressure Judgment Based on Image Processing

When car is in the process of high-speed, the faults caused by tire pressure anomalies are the most worried and difficult to prevent for all drivers. It is one of the important reasons for the sudden traffic accidents. Tire pressure related to ride comfort, fuel consumption, tire wear and vehicle safety, so tire pressure’s monitoring has been one of the important research directions in the safe driving of vehicle. The anomalies of tire pressure made the vehicles appear to tilt and shorten the distance between rim centres and the ground. Using image technology can detect intuitively and fast. This paper measures the dynamic tire pressure based on image processing technology. The vehicles tires goal was extracted by three image differences. After morphological processing, it used three methods to make comprehensive analysis and judgement of whether the tire pressure is normal, to realize the automation and intelligence. This method had realized real-time non-contact detection for dynamic tire pressure, which has extended significance to popularize.

Bulb turbine operating at medium head: XIA JIANG case study

With lots of references for 4-blade bulb turbines, such as these of Wu Jin Xia (4 units – 36.1 MW per unit – 9.2 m rated head), Chang Zhou (15 units – 46.7 MW per unit – 9.5 m rated head) and Tong Wan (4 units – 46.2 MW per unit – 11 m rated head), ALSTOM Power Hydro is one of the major suppliers of bulb turbines operating under medium head for the Chinese market. ALSTOM Power Hydro has been awarded in November 2010 a contract by Jiang Xi Province Xia Jiang Water Control Project Headquarters to equip Xia Jiang's new hydropower plant. The power dam is located on the Gan Jiang river, at about 160 km away from Nan Chang town in South Eastern China. The supply will consist in 5 bulb units including the furniture of both the turbine and its generator, for a total capacity of 200 MW, under a rated net head of 8.6 m. The prototype turbine is a 7.8 m diameter runner, rotating at 71.4 rpm speed. For this project, ALSTOM has proposed a fully new design of 4-blade bulb runner. This paper outlines the main steps of the hydraulic development. First of all, a fine tuning of the blade geometry was performed to enhance the runner behaviour at high loads and low heads, so that to fulfill the demanding requirements of efficiencies and maximum output. The challenge was also to keep an excellent cavitation behaviour, especially at the outer blade diameter in order to avoid cavitation erosion on the prototype. The shape of the blade was optimized by using the latest tools in computational fluid dynamics. Steady state simulations of the distributor and the runner were performed, in order to simulate more accurately the pressure fields on the blade and the velocity distribution at the outlet of the runner. Moreover, draft tube computations have been performed close to the design point and at higher loads. Then, a model fully homologous with the prototype was manufactured and tested at ALSTOM's laboratory in Grenoble (France). The model test results confirmed the predicted ones: the expected weighted average efficiency is higher than the guaranteed value and the maximum output was reached with a comfortable safety margin. A comparison of the experimental and numerical velocity probings under the runner is also proposed as an insight into the prediction of flow behaviour at the inlet of the draft tube.

Assessment of Pedestrian Level Wind Environment of a Group of High-Rise Buildings Based on Numerical Simulation

The pedestrian level wind environment including wind comfort and wind safety was assessed with the Computational Fluid Dynamics (CFD) method. The joint probability distribution of the local wind speed and direction information was obtained using the raw meteorological data. The aerodynamic information of the entire flow field was obtained using CFD software. The results of the assessment of pedestrian wind environment were obtained using the Lawson's criterion of wind comfort and wind safety. The results indicated that there are potential safety risks near the corners around the high-rise buildings (5-10m regions). Pedestrians should avoid accessing these areas. The areas can be set to green areas. Most of other areas are comfortable and safe for pedestrians. Some areas are not suitable for long-term standing or sitting.

The Key Technology Research of Building Automation System

Contemporary building automation system (BAS) is realize automatization control and management system through to the modern advanced computer technology, communication technology and control technology, and other comprehensive utilization,which can realize the intelligent buildings all mechanical and electrical equipment and the energy equipment of the united network control connection, so as to achieve the whole building environment system of monitoring and management, to it’s best for people to create a comfortable safety, high efficiency and energy saving life environment. In this paper, there’s a deep discussions of the building automation system of composition, development and the present situation; and the key technology of the present situation and development prospects, and we set a plan based on the technology of building automation system LonWorks solutions, and expounds the concrete realization of key technologies of the system, based on the development of the host general much input/output intelligent node module.

A research about the comfort level of decubitus positions among pregnant women with premature rupture of membranes

Objective To study the safety of using special position for pregnant women with premature rupture of membranes Methods A total of 146 pregnant women with premature rupture of membranes were surveyed by questionnaires applying 3 different positions,the results were summarized and analyzed.Results The comfort levd and safety of improved position were significant better than those of other positions.Conclusions The improved position can meet the need of pregnant women with premature rupture of membranes,it is worthy of spreading. Key words: Premature rupture of membranes; Position; Comfort level

The use of conjoint analysis in the design of bicycle-related clothing

Product design is a creative decision-making process that aims to satisfy human needs by releasing good products that can appropriately meet the preferential requirements of customers. In the development of new products, the designer must identify the preference and attitudes of customers toward certain products, ascertain the factors that make products popular in the market, and devise optimum design plans for those products. Biking has become a popular activity due to its contribution to maintaining health. Bicycle-related clothing is known to play an important role in comfort level and safety. Unfortunately, there is hardly any research or designs that consider customer preferences in the bicycle-related clothing design process. Many manufacturers mainly focus on the improvement of the material properties of clothes instead of clothing design to meet the customer requirements. This study uses conjoint analysis in bicycle-related clothing design to provide designers with an efficient approach to identify customer preferences. The lifestyles of users are examined through a massive amount of collected data used to design an attitude measurement chart/questionnaire. Customer requirements are subsequently categorized through factor analysis, and critical requirement attributes are identified for conjoint analysis. Finally, conjoint analysis is used to obtain the optimal design combination for bicycle-related clothing that adheres to the preferences of customers.

Stereo-vision applications to reconstruct the 3D texture of pavement surface

Characterisation of pavement surface texture has significant effects on ride comfort and road safety. Pavement texture is typically reported as a single attribute, such as mean profile depth, root mean square roughness or hydraulic radius, which limits the usefulness of information extracted from texture measurements. Therefore, advanced methods that characterise pavement texture in three dimensions are needed. This paper reviews recent advances in the development of two imaging-based texture evaluation methods. The main objective of these methods is to recover the 3D heights of the pavement surface. Also, the validation of the proposed image-based texture indicators is examined. Results show that image-based techniques can be successfully applied to recover the 3D heights of pavement surface textures and provide substantial information on the friction and noise characteristics of the surface.

Optimization Design of Ride Comfort for Wind Blade Transporter

The wind blade transporter, a vehicle transporting wind blade, is a new product required by the market. It is supposed to have high level of ride comfort as required by the special load it carrys. Mathematical model of optimization of transporter ride comfort is established with sum of the acceleration RMS of blade centroid and wheel relative dynamic load as objective function. The wind blade transporter is taken as an example while SQPM is used as the optimization strategy. The results show that the ride comfort and operation safety of the transporter could be improved when the inflatable pressure and volume and stiffness of damping device are adjusted.

A Waste of Space: Bodies, Time and Urban Renewal

A Waste of Space: Bodies, Time and Urban Renewal

Less iodine injected for the same diagnostic performances: comparison of two low-osmolar contrast agents (iobitridol 350 and iopamidol 370) in coronary angiography and ventriculography: a randomized double-blind clinical study

Objective — Mild reductions in iodine concentration could reduce acute side effects after intraarterial contrast media administration without affecting the quality of coronary artery images. This study was designed to show the equivalence in terms of image quality of two nonionic low-osmolar monomers, iobitridol 350 and iopamidol 370, and to compare their clinical safety in coronary angiography and ventriculography.Methods and results— In this multicentre, double-blind clinical trial, 98 adult patients were randomized to receive either iobitridol 350 or iopamidol 370.The image quality (primary evaluation criterion) of the whole examination was assessed using a 5-point scale (poor, fair, moderate, good, excellent). Secondary endpoints were the image quality per territory, diagnostic efficacy, practical comfort (5-point scale: impossible to evaluate, not practical, moderately practical, practical, very practical to use) and clinical safety (adverse events and vital signs).he proportions of examinations presenting with good or excellent global image quality was similar with both contrast media: 87.8% with iobitridol 350 vs. 89.8% with iopamidol 370. Similar results were observed when considering the image quality specifically for each major coronary artery and left ventricle. No difference between groups was found with respect to other secondary criteria. Adverse events occurred in 7 patients with iobitridol 350 (14.3%) and in 10 patients with iopamidol 370 (20.4%).Conclusions — This study showed that, with regard to image quality and diagnostic efficacy and using a lower iodine concentration, iobitridol 350 was comparable to iopamidol 370 in adult patients requiring coronary angiography and ventriculography for diagnostic indications.

Freezing desalination of sea water in a static layer crystallizer

This work aims in developing a static layer crystallizer for freezing desalination of sea water. The experiments were performed with a simple system of H2O-NaCl and with samples of sea water from Rabat. The pilot crystallizer consists in a tube cooled bymeans of a thermostatic bath. The tube is immerged in a cylindrical double jacketed tank cooled by means of a second thermostatic bath. The brine is poured into the tank and the crystallization takes place on the external surface of the tube. The global process is divided into 4 steps: (i) crystallization of the ice layer by controlling the cooling rate in the tube (ii) draining off the concentrated brine (iii) purification of the layer by sweating and (iv) melting of the ice to recover the fresh water. A parametric study of the effect of the operating parameters has allowed us to quantify the role of the different key parameters of the crystallization step. Within the studied domain, the purity of the crystalline layer was mainly affected by the initial salinity of the brine. The growth rate of the layer, controlled by the cooling rate in the tube, had also a significant effect. Experiments performed with Rabat sea water showed that a fresh water of salinity close to the drinking water standards could be obtained in one stage within 31 h. Desalination operated in two consecutive stages (10 h þ11 h) gave salinity below the standards with a comfortable safety margin. If sufficiently severe operating conditions are applied, sweating is able to purify the interior of the ice layer and to reach the drinking water standards, provided the impurity concentration of the ice produced in the crystallization step is low enough. The mass loss induced by sweating is also high when the impurity concentration is high. These first results are promising and show the feasibility of the process which still requires to be optimized.

Subjective evaluation of a simple active noise control system mounted inside an earth moving machine cab

A series of experiments were carried out in order to verify the feasibility of an active noise control (ANC) approach to improve the acoustic comfort at the operator's station of a compact loader. For this kind of application expensive noise control solutions would be too expensive for the market and therefore unsuitable. Hence, a very simple active noise control layout using a single channel feed-forward scheme was used. Its capability to reduce the dominant low frequency noise components and the overall level within the space where the operator's head is located during his/her work was experimentally verified. Then, the modifications caused by this ANC system were subjectively evaluated with regards to some important noise features (tiredness, concentration loss, loudness and booming sensation) in order to qualify comfort and working safety conditions for the operator.

Wearable that achieves Society of Safe Comfortable Safety

Wearable that achieves Society of Safe Comfortable Safety

Flexible seat concept for improved occupant protection

From an ergonomic point of view, the backrests of present-day vehicle seats are a compromise that take account of the different stature of the occupants only to a limited extent. In order to improve comfort and passive safety in vehicles, Bertrandt AG has joined forces with partners to develop an innovative seat concept that can be adjusted to fit the individual length of the occupant’s back.