Morphogenesis Analysis for Digital Image Production with L-System

The process of forming an image requires a correct color composition, location and distance between the lines to produce a good image. Human abilities in both creativity and high imagination are very limited, especially in forming new images by utilizing existing image patterns or images that resemble old images. Here we showed the implementation of L-System to generate new image generations with additional flame as a fire effect/glow on images for image transformation. This research used the L-System algorithm, Iterated Function System, and Voronoi Diagram to improve the result of image transformation. The results of this study indicated that mathematical calculations can be applied in the formation of images and the resulting images can be abstract and symmetrical. The next generation of images produced in this research can be in unlimited numbers as the generation of morphogenesis processes. The process of generating images is carried out randomly by merging the two existing images with morphogenesis analogy. The resulting images can be exported into jpg, png, and svg formats. Furthermore, this research showed that the implementation of the calculation for the variation reach the value of 99.48% while the image variation composition has a value of 99.29%.

Steel Fiber Enhancement upon Punching Shear Strength of Concrete Flat Plates Exposed to Fire Flame

In this study, the effect of fire flame on the punching shear strength of steel fiber reinforced concrete flat plates was experimentally investigated using nine half-scale specimens with dimensions of 1500×1500 mm and a total thickness of 100 mm. The main investigated variables comprised the steel fiber volume fraction 0, 1, and 1.5% and the burning steady state temperature 500 and 600 °C. The specimens were divided into three groups, each group consists of three specimens. The specimens in the first group were tested with no fire effect to be the reference specimens, while the others of the second and third groups were tested after being exposed to fire-flame effect. The adopted characteristics of the fire test were; (one hour) burning time duration and 500 and 600 °C steady state temperature with sudden cooling process (water sprinkling directly after burning). The test results proved that exposing to direct fire effect for one hour caused a reduction in the punching shear strength with an increase in the ultimate mid-span deflection. Also, it was noticed that using steel fiber in the concrete mix leads to a significant increase in the punching shear strength for both the unburned and burned specimens. The ultimate punching load increased by about 11 and 16.6% for the unburned specimens with 1.0 and 1.5% steel fiber volume fraction, respectively, and by about 22.4 and 19% for the burned specimens at 500 °C with 1.0 and 1.5% steel fiber volume fraction, respectively. While, it was increased by about 29.2 and 21.5% for the burned specimens at 600 °C with 1.0 and 1.5% steel fiber volume fraction, respectively, as compared with the reference specimen of each group. Doi: 10.28991/cej-2021-03091751 Full Text: PDF

A Review of Precast Concrete Beam-to-Column Connections Subjected to Severe Fire Conditions

Fire exposure can have a significant impact on the structural integrity and robustness of precast concrete beam-to-column connections. Given the importance of fire safety in the design of a structure, it is critical to understand the damage that may occur in the event of a fire to be able to prevent the building from collapsing. No comprehensive study has been carried out to determine the effects of fire on semirigid and pinned concrete beam-to-column connections. Most studies focused on the impact of exposure of rigid concrete beam-to-column connections to high temperatures. This paper is a comprehensive review of the literature on the performance of precast concrete beam-to-column connections under fire conditions. The key areas in this review are the moment-rotation-temperature characteristics and fire effect on precast concrete beam-to-column connections. This paper focuses primarily on the case studies of real fires, large-scale fire tests, computer simulations and analytical models, fire resistance tests on the connection elements, and assessment and rehabilitation of fire-damaged precast concrete. The paper also discusses the current issues and possible challenges.

Evaluating Socioecological Wildfire Effects in Greece with a Novel Numerical Index

Large-scale wildfires have become more frequent in Greece and coupled with the country’s limited economic resources, investments in both pre-fire planning and post-fire rehabilitation for most affected areas are not feasible. From the perspective of forest and fire management agencies, the severity and importance of fire effects are evaluated based only on total area burned, while from a societal standpoint, by the number of fatalities and destroyed houses. A holistic approach to rank wildfires with an inclusive assessment of all their effects is missing. We developed a new evaluation and ranking index based on expert judgment, the study of 50 large-scale fire events in Greece and a detailed review of the literature, to develop a set of categories and criteria to assess ecological and socioeconomic effects of wildfires. The Fire Inventory and Ranking of Effects (FIRE) Index provides a comprehensive and easy-to-use semi-numeric framework that combines scores from seven fire effects categories and 56 criteria through a user-friendly web-platform. The seven categories include fire effects on landscape and vegetation, general environmental impacts, regeneration potential and vegetation recovery, casualties and fatalities, destruction and damages to infrastructure, economic losses, and firefighting and wildfire suppression. Each of the 56 criteria within these categories describes a different anticipated fire effect. The magnitude of each fire effect criterion is estimated by predefined ranked choices by one or more persons/assessors in a multi-level evaluation procedure. We apply the FIRE Index assessment to a significant 5900-ha wildfire that occurred in 2011 in northern Greece, including a sensitivity analysis of how different category weights impact the final index score. More diverse metrics to assess wildfire effects will help address the complex social and biophysical dimensions of the wildfire governance challenge and help guide pre- and post-fire management actions.

Contaminated Land by Wildfire Effect on Ultramafic Soil and Associated Human Health and Ecological Risk

The purpose of this study is the evaluation of fire effect on contaminated land and the assessment of the associated risk of human health and terrestrial ecological receptors. Ash and soil samples were gathered from burned and unburned areas (central Evia, Greece) which are adjacent with a Natura 2000 area. The geochemical dataset includes 20 sampling sites and 35 elements. The wildfire severity was investigated by applying a macroscopic approach and field observations. Statistical and spatial analysis were applied for delineating the distribution of elements in ash and soil. Elemental balance approach was performed for estimating net gain (+) or loss (−) to the ash. Element contents in sampling sites were compared to screening values proposed by the literature. Hundreds of hectares of burned land including wildland areas in central Evia are contaminated with (contents in mg Kg−1), Co (up to 43.5), Cr (up to 244), Mn (up to 1158), Ni (up to 463) associated with geogenic sources such as serpentinite peridotites and Ni-laterite deposits. Aluminum, As, Cd, Co, Cr, Fe, Mn, Ni, Pb, V and Zn contents recorded in the sampling sites are posing a potential risk to human health and ecological receptors.

Ultrasonic Assessment of the Concrete Residual Strength after a Real Fire Exposure

After a fire, the assessment of concrete residual strength can be a challenge. Since the strength reduction depends on the distance from the heated surface examination based on destructive test, i.e., core samples, is not precise enough. Therefore, more detailed methods can establish the influence of the high temperature in the zone, which no longer has visible cracks. That method can be used to assess layer thickness to remove due to the fire damage. The Ultrasound Pulse Velocity (UPV) method with point heads was used in the paper to examine samples taken from a structure after the real fire. Moreover, to make the analysis more precise, an effect associated with the porosity in concrete was also considered to separate pure fire effect.

Modification of Interaction Forces between Smoke and Evacuees

The most used fire effect models on evacuees are only focused on the physical capacity of the evacuees. However, some of the evacuees in a fire situation continuously move through the familiar route, although the familiar route is smoke-filled and they know that they are moving towards the fire source. Thus, the additional evacuation models are required for considering the behavioral changes due to the psychological pressure when the evacuees are moving through the smoke or towards the fire source. In this study, the inner smoke region force is modified to improve the accuracy and practicality of the BR-smoke model by varying the walking speed according to the smoke density. Additionally, the BR-smoke model is applied to FDS+Evac to compare the simulation results of the modified BR-smoke model with those of existing models. Based on the results, the evacuation characteristics inside the smoke region can be improved by using the modified BR-smoke model because the evacuees are continuously influenced by the modified inner smoke force inside the smoke region. However, additional studies for determining more reliable evacuee psychological factors are required to improve the reality of the modified BR-smoke model.