The present study deals with isolation, identification and characterization of some indigenous heavy metal resistant bacteria isolated from rhizosphere of Tagetes minuta, growing in soil adjoining automobile workshops to investigate their bioaccumulation capacity for three selected metals Cr(VI), Ni(II) and Cd(II). The plant was selected due to its natural abundance in the climate of Kashmir and also in the area of study. On the basis of morphological, biochemical, 16S rRNA gene sequencing, the isolates were identified as B. cereus BDBC01, B. cereus AVP12 and B. cereus NC7401. At maximum studied concentration of metal ions (250 mgl-1), in above sequence, the strains accumulated 118.2, 121.87 and 90 mg/g Cr (VI), 135, 127.5 and 146.25 mg/g Ni (II) and 120, 129.37, 135 mg/g Cd(II). Langmuir and Freundlich models were applied and found suitable to describe biosorption of selected metals by the isolated strains.

For welded bridge components, the knowledge of residual stresses induced by welding is essential to determine their effect on the fatigue life behavior resulting in optimal fatigue design and a better knowledge about the fatigue strength of these welded connections. The residual stresses of a welded component in an orthotropic steel bridge deck are determined with the incremental hole-drilling method. This method is specified by the American Society for Testing and Materials ASTM E837-13a and it can be used only when the material behavior is linear-elastic. However in the region of the bored hole, there are relaxed plastic strains present that can lead to significant error of the measured stresses. The hole-drilling procedure is simulated with three-dimensional finite element modeling including a simplistic model of plasticity. The effect of plasticity on uniform in-depth residual stresses is determined and it is concluded that residual stresses obtained under the assumption of linear-elastic material behavior are an overestimation. Including plasticity for non-uniform in-depth residual stress fields results in larger tensile and smaller compressive residual stresses. Larger tensile residual stresses cause premature fatigue failure. Therefore, it is important to take these larger tensile residual stresses into account for the fatigue design of a welded component.

Concrete is a popular building material all over the world, but because of different physiochemical processes, it is susceptible to crack development. One of the primary deterioration processes of reinforced concrete buildings is corrosion of steel bars within the concrete through these cracks. In this regard, a self-healing technique for crack repair would be the best solution to reduce the penetration of chloride ions inside concrete mass. In this study, a rapid chloride migration (RCM) test was conducted to determine the self-healing capacity of cracked mortar. With the help of the RCM test, the steady-state migration coefficient of cracked and uncracked specimens incorporating expansive and crystalline admixtures was calculated. Based on the rate of change of the chloride ion concentrations in the steady-state condition, the migration coefficient was calculated. Furthermore, bulk electrical conductivity tests were also conducted before and after the migration test to understand the self-healing behavior. It was evident from the test results that the self-healing of cracks was helpful to reduce the penetration of chloride ions and that it enhanced the ability of cracked mortar to restrict the chloride ingress. Using this test method, the self-healing capacity of the new self-healing technologies can be evaluated. The RCM test can be an acceptable technique to assess the self-healing ability of cement-based materials in a very short period, and the self-healing capacity can be characterized in terms of the decrease of chloride migration coefficients.

This study aimed to investigate the effect of autogenous healing capacity with the addition of expansive and crystalline agents on mechanical and fracture behaviors of fiber-reinforced (FR) mortar specimens with crack mouth opening displacement (CMOD) controlled test set-up. The experimental results of a self-healing approach of FR mortar were analyzed in terms of first cracking peak load (FCPL) increase, index of fracture toughness recovery (IFTR), and index of fracture energy recovery (IFER). Initially, the specimens were pre-cracked at different crack widths ranging from 30 μm to 200 μm after 28-days of curing. After pre-cracking, the specimens were kept in water for 56- and 120-day healing. A controlled three-point bending test (PBT) was applied on prism specimen having a central notch of 40 mm depth for pre-cracking as well as the post-conditioning stage for determining the FCPL. However, the crack surfaces were monitored by a high-range digital microscope and scanning electron microscope (SEM) to examine the nature of healed products near the damaged area. Test results revealed that a significant recovery of small cracks (≤50 μm) could be achieved for self-healing specimens by using healing agents (HA), while for large cracks (≥100 μm) partial recovery could be achieved after the 120-day healing period.

Risk perception influences cycling attributes toward its adoption. Researchers are investigating attributes associated with risk formation. In this study, various attributes were selected which influence the user’s formation of risk perception. For this purpose, an online questionnaire survey was conducted in Flanders, among all segments of the population (N = 774). Participants were asked questions for attributes relating to risk formation. Results suggested that risk formation among users evolves around tangible to non-tangible attributes. The spectrum of risk perception was developed which visualizes risk evolution, considering various attributes. Surprisingly, elements such as “comfort”, surface evenness, and policies were rated as being neutral. Infrastructure and the presence of opposite road users tend to be foreseen as critical factors for risk formation. Risk perception varies depending upon psychometric paradigm shifts, such as dread and unknown risk. This strange notion is considered to lie in a space between dread and unknown risk. This explains the difference in risk perception, knowingly or not knowingly (subconsciously), yet expressing cognitively and evolving inside. This is an interesting finding, but reasons behind such a motive need to be explained. A possible explanation behind such behavior is that people tend to change their responses due to knowledge acquisition during the survey.

An advanced design classification system for bicycle paths, based on geometric features and force equilibrium, can pave the way for improved bicycle safety, accident prevention and the development of design guidelines. A design and classification system does exist for bicycle paths, but the number of accidents has led to ambivalence about its validity and effectiveness. In addition, a universally accepted classification system has not yet been approved or adopted. This paper presents a unique set of design parameters, analytically developed based on formulas that consider the physical characteristics and dimensions of individual bicycles. The proposed design system is based on theoretical trigonometric derivations. The model was validated with the real-world geometry of the transportation infrastructure of the city of Antwerp, Belgium. The conclusions of this study are useful for evaluating the effectiveness of bicycle paths during the design stage without the necessity for real-world experiments. The results will thus be valuable for stakeholders working on policy frameworks, bicycle safety and riding comfort.