To estimate and model explosion pressure rise in closed volumes, industrial applications require a simple method. Ideal gas model is capable to assume pressure rise values to 10% above to initial pressure. However, most of the explosion venting devices opens higher than this pressure range.
Extension of ideal gas model was carried out in this paper. Authors made some experimental studies in 20 L explosion sphere at ambient temperature and atmospheric initial pressure, with propane-air mixtures at different concentrations between 2.8 and 6.3 vol%. They measured pressure values inside the chamber during explosion and recorded at 9,600 Hz. Based on experimental studies, authors extended ideal gas model application range to 1.5 barg.
This study aims to select the suitable density of the material according to the mechanical properties needed by the 3D-printing application in which it will be used. 3D-printed carbon fiber filaments with different printing densities have been tensile, and a fatigue test was experimented with to find the mechanical properties. Furthermore, the modulus of elasticity, yield stress, and ultimate tensile strength of the material was determined by analyzing the stress-strain curves. The result shows that the parts printed with a high infill density give better mechanical properties, more time to build the object, more strength, and heavier weight than those printed with low infill density.
Accessibility is known as the ease of reaching destinations. The accessibility is determined by the spatial distribution of potential destinations, and the magnitude, quality, and character of the activities found there. However, modernization and the fast expansion of urban development transform cities' local cultural life from walkable accessible places to just car places. This has encroached into every corner of our urban environment today. In addition, the available services and systems to manage the pedestrian movement in the historic core are inadequate and inefficient, posing risks to both the traffic and the pedestrians. That affects the walkability for cities gradually. Hence, this paper aims to explore the main physical elements that contribute toward accessibility under three main categories (pedestrians, vehicles and public transport) as one of the walkability characters in Salt City in Jordan. Historical review, site analysis, and survey were the main methodology used in this study.
Cracking in composite steel-concrete bridge decks is a common problem in civil engineering. Before, or shortly after, the bridge is subjected to live loads; various levels of cracking can appear, mostly due to plastic shrinkage and temperature effects.
This paper presents an investigation of the behavior of cracked concrete in a composite deck slab of a railway bridge supported by steel girders using the finite element method. Eurocode 4-2 proposes a few simplified methods for calculating shrinkage and cracking effects in concrete. Through the proposed methods of analysis, an analytical simulation of a continuous composite steel-concrete bridge deck is performed and some practical recommendations for analyzing beam girders of this type are given.
Metal injection molding has undergone great growth in the last years and is widely used in the manufacturing of small-sized and geometrically complex metal parts in high-volume production series in many applications. This paper makes overview of the integrity evaluation of metal injection molding production. Digital radiography can automatize the process of controlling various discontinuities inside the material, with sensitivity acceptable by the standard. Image processing through software Rythm Review 2.2, allows the detection of discontinuities in complicated geometric shapes. Tests were made on items with thicknesses 3 – up to 8 mm, with complicated geometry. The result is satisfactory in terms of localization and evaluation of defects in both dimensions and typology.
This paper presents an experimental work of using crushed glass mixed with the poorly graded sandy soil to investigate the possibility of shear strength parameters improvement using the direct shear test. The crushed glass is sieved and prepared for seven sets of percentages, the collected percentages of crushed glass represented a mix of glass retained on sieves No. 4, No. 8, No. 30, No. 100, and No. 200 and were added as a weight ratio of the sample for many cases. The main results of this work show that the mixing 10% of crushed glass for sieves No. 8, No. 200, and No. 50 increase the angle of internal friction of poorly graded sand (Ø˚) about 15%, 3%, and 29% respectively, and mixing 10% of crushed glass retained on sieve No. 4 decrease Ø˚ about 40%.
This study evaluates future hydrological alterations caused by climatic changes until 2100 using climate change scenarios. The indicators of hydrologic alteration software program assess predicted changes in flow characteristics and the degree of hydrological alteration obtained through a range of variability approach analysis. The study was performed on the Hron River basin in Slovakia, using the daily discharges from the observation period of 1981–2010 and a modelled scenario of daily discharges until 2100. The time period investigated was divided into three periods among which four ranges of variability approach analysis were conducted. The study results presented assume an increased incidence of drought in the summer months. In the winter months, the period of increased flows is expected to intensify.
The natural fibre containing cellulose as its main component that can be used as an alternative material to improve the strength of polymer composites. Paper focused on the determination of the best volume fraction of sugarcane fibre-reinforced polymer composites. Three variants of alkalization time were carried out. The highest average value of the tensile test results was obtained at an alkalization time of 1.5 h with a tensile strength of 41 N mm−2 and elongation correspond to 11.806% where the highest bending test results were obtained at an alkalizing time of 0.5 h with a bending strength of 24.89 N mm−2. The results of mechanical interlocking have been observed on macrostructure photo and at 1.5 h of alkalization are better than 0.5 h and 1 h of alkalizing time.
This manuscript proposes a novel adaptive restarting genetic algorithm-based solution approach for rescheduling generation-based congestion control. The generator sensitivity values are considered to select generators to participate in the congestion management. The efficacy of the suggested technique is demonstrated on a 39-bus New England system and a modified IEEE 30 bus system, and a comparative study with other optimization strategies are established. The findings produced with the suggested technique for congestion management better the outcomes obtained with different methods. The presented approach ensures a superior convergence profile by eliminating local minima traps. This method also assists the independent system operator in managing congestion more efficiently.
A major object of prosthetics fitting procedure his to provide the amputee with the greatest potential long-term rehabilitation result by providing the finest feasible design. The foot keel and ankle joint are two key components for transtibial prosthetic users. This essay's objective is to determine the effect of systematically altering the stiffness of prosthetic foot keel and ankle joint on standing in individuals who have undergone unilateral transtibial amputations. A balance analysis was carried out to select the optimal combination of prosthetic foot and joint. According to the findings, the medium foot and soft ankle joint is the best one for standing analysis.