10368 research outputs found
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Comparing the Effectiveness of various Crosswalk Designs in New York City
No full textOver the years, vehicles have gotten progressively larger, creating a larger risk for pedestrians.,This is also amplified by city infrastructure, which prioritizes vehicular traffic. The purpose of this study was to take certain crosswalk designs, test them, and compare them to the traditional design found across North America. It was hypothesized that the most effective design would be the speed hump. This hypothesis was tested by using the AnyLogic simulation software. A control was set up with a simple crosswalk with crossing lights, along with adding a crosswalk with LED signs and a speed hump later on. A map of New York City was designed and the pedestrians were set up to come at a rate of 175 people per hour, calculated to be 1,533,000 people in the simulated year. Six trials were conducted for each group. Findings show that the speed hump had a 51.9% decrease in pedestrians hit and the LEDs had a 45.6% decrease. The p-value of less than .001 at a 95% confidence level showed that the speed hump was most effective. However, both solutions reduced the number of pedestrians hit significantly compared to the control. Crosswalk design does have an impact on pedestrian safety and a study like this could be used to improve city design guidelines
Simulating a Cable System for Broken Pylons of Suspension Bridges to Prevent Bridge Failure from Eathquakes Using Houdini SideFX
No full textLong-span bridges can be subject to collapse due to corrosion and natural events, such as earthquakes, that can cause severe damage afterwards. Many studies have looked into the different types of corrosion bridges experience as well as the tension and pressure earthquakes can inflict onto a bridge. The purpose of this study was to model a cable system that would support the lower part of a broken pylon of the Kurushima Kaikyo Bridge and simulate it through different types of earthquakes. It was hypothesized that the tension of the suspenders would decrease at least 10% and prevent the bridge from collapsing. Four earthquakes were simulated and tested on the bridge for 30 trials with or without the cable system. The results showed that the bridge could not withstand any of the earthquakes with and without the cable system. The simulation showed that despite the cable system delaying the bridge collapse, the suspenders around the midspan would still break due to the stress exerted on them, resulting in a chain reaction of other suspenders breaking due to taking on the stress of the broken suspender adjacent to it. Future research should focus on supporting the weight of the bridge deck instead of the pylons
Assessment of Microplastic Release and Rate of Release Over Time from Various Plastic Polymers Under Environmental Exposure in a Humid Subtropical Environment
No full textDespite being one of humanity\u27s most important materials, plastic, specifically plastic waste, has become a major environmental concern. This study aimed to determine the degradation rates of plastic polymers in a subtropical soil environment over time. With the growth of plastic use comes the risk of microplastics (MPs), small plastic pieces less than 5 millimeters in size, that break off from larger items (NOAA, 2021). It was hypothesized that polyvinyl chloride (PVC) would exhibit the slowest degradation rate due to its weather-resistant properties. This study investigated degradation rates and MP release from various plastic polymers, including both single-use plastics (SUPs) and non-SUPs, in a humid subtropical environment. Four different plastic polymers, polyethylene terephthalate (PET), high-density polyethylene (HDPE), PVC, and polystyrene (PS), were exposed to environmental conditions in controlled soil environments over eight weeks. MP concentrations were measured biweekly through a microscopic analysis following a density separation. A two-way ANOVA revealed a significant effect of time (p = .0003) on MP release, while the effect of polymer type approached significance (p = .091). PET showed the highest MP release, followed closely by PS. HDPE and PVC showed moderate increases, with control samples showing minimal change. The interaction between time and polymer type was not significant (p = .1809), suggesting similar degradation rates/patterns across all tested polymers. These findings provide insight into the degradation rates of different polymer types in terrestrial environments, contributing to our understanding of plastic pollution and informing policy decisions regarding plastic use and management
The Combined Effects of Curcumin and Melaleuca quinquenervia L. Oil on Inhibiting the Overgrowth of Staphylococcus epidermidis
No full textStaphylococcus epidermidis is a common skin bacteria known to be an opportunistic pathogen when there is an overgrowth. The effect of overgrowth causes damage to the skin barrier ultimately resulting in dry skin and diseases such as eczema (Brown & Horswill, 2020). Many studies have concluded that curcumin has many antimicrobial properties against S. epidermidis in inhibiting bacterial growth. Niaouli oil has also been tested individually with results suggesting that the essential oil can effectively inhibit bacterial growth due to vitamin E content. This study aimed to combine curcumin and niaouli oil to make a solution that would most effectively inhibit the growth of S. epidermidis. It was hypothesized that as the concentration of niaouli oil and curcumin increases in a solution administered to Staphylococcus epidermidis, the growth of bacteria will be more effectively inhibited. Four groups were formed for testing, three being experimental groups. Each experimental group had 30 trials with sterile disks soaked in different niaouli oil and curcumin concentrations placed in the middle of each quadrant. After incubating for three days, no zones of inhibition were formed. This was likely due to olive oil being used as a solvent. Olive oil may have disrupted the potential of niaouli oil and curcumin, which resulted in no-zone formations. An ANOVA statistical analysis would have been utilized if the results collected showed value. In future studies, it would be beneficial to use a larger concentration of niaouli oil so that it can be used as the solvent for curcumin
The Antifungal Efficacy of Handroanthus impetiginosus Extract (Pau D’Arco) on the Growth of Aspergillus niger
No full textFungal contamination poses significant threats to various industries, highlighting the need for natural antifungal agents. Handroanthus impetiginosus has been historically reported to exhibit significant antimicrobial and antifungal, but its effects on certain filamentous fungi are limited. The purpose of this study aimed to evaluate the antifungal properties of Pau D’Arco extract combined with olive oil, against Aspergillus niger as an application to develop a natural fungal pesticide. The hypothesis stated that increasing concentrations of Pau D’Arco would inhibit the growth of A. niger, due to antifungal compounds being able to restrict and inhibit fungal growth. Three groups were tested for 90 trials: one control and two experimental with varying Pau D’Arco concentrations. 30 discs were soaked in each suspension and placed in the center of each quadrant of A. niger plates grown on potato dextrose agar. The plates were incubated for 48 hours. No measurable and visual zone of inhibition was observed, and fungal overgrowth occurred in all 90 trials. It was determined that fungal overgrowth was due to environmental factors or a low-quality extract. Factors such as pH, oxygen levels, moisture, and chemical fumes would cause a deviation in the natural growing pattern of A. niger, leading to spiking proliferation and overgrowth of the fungi. Strictly controlling environmental factors and using higher-quality extracts can produce better results. In addition, carefully researching higher-quality extracts that are more soluble in oil and can contain higher amounts of antifungal compounds can be beneficial to obtain better results
Efficacy of Curcumin as a Substitute for Fluorescent Eye Stains in Gelatin Models
No full textCorneal abrasions, which are small abrasions that can occur on the surface of the cornea can happen to anyone, especially those who have high intensity and laborious jobs. The primary method to detect these abrasions is fluorescent eye stains. However, these stains can be inconvenient and expensive, so the purpose of this study was to determine if curcumin could be used as a viable substitute for fluorescein eye staining due to its low cost and easy accessibility. It was hypothesized that if curcumin was applied to an incision made in a gelatin model of the cornea, then the curcumin would stain the incised area without staining the unincised areas. This is based on the reasoning that the incised areas would catch the dye, similar to a fluorescent eye stain, whereas the smooth areas would repel it. Models of the cornea were created using clear, unflavored gelatin in hemispherical shapes. Various depths of incisions were made into these corneal models, and a prepared curcumin solution was poured on top of each incision. The amount of leftover curcumin solution was then measured. Both a one-way ANOVA and Tukey test were run. The tests only showed significance between the 7 mm and 10 mm groups. The hypothesis was partially supported, because the 5 mm and 10 mm incision groups had less leftover solution than the Control, however the 7 mm had more. Based on these findings, it can be concluded that curcumin is a viable alternative for fluorescein eye staining
