Comparing Flashover Heat Release Rate Within Different Materials

Fire model systems hold great value in helping figure out what happened during a fire, how a fire could have been prevented, or how a hypothetical fire would behave. This is important in both reconstructing a fire and preventing fires in buildings. Spreadsheet models calculate mathematical solutions for inputted conditions including the type of material ignited. This study examines the Fire Dynamics Tools (FDTs) (Stroup et al., 2013) spreadsheet model (Chapter 13) that tests the minimum heat release rate (HRR) within compartments for flashover. Flashover is the most dangerous phase of a fire in which surfaces exposed to thermal radiation read ignition temperature. The smaller the HRR, the faster flashover will occur. This model determines how quickly flashover will occur in different settings. Using this model, it was hypothesized that flashover would occur faster in a smaller compartment made of brick than one made of concrete. To test this hypothesis, the width of the compartment was changer between 1-40m, keeping the rest of the parameters of the compartment constant. This was repeated for both brick and concrete. The model has three methods of calculation providing varying output values. It was found that for both rooms of brick and concrete, the larger the width the slower flashover occurs with a room made of brick reaching flashover faster. Additionally, one method, Babrauskas, did not show any change in HRR when the width of the compartment was changed, demonstrating a limit to this model

Development of a Surface-Enhanced Raman Spectroscopy Method for the Detection of Benzodiazepines in Urine

Benzodiazepines are among the most prescribed compounds for anti-anxiety and are present in many toxicological screens. These drugs are also prominent in the commission of drug facilitated sexual assaults due their effects on the central nervous system. Due to their potency, a low dose of these compounds is often administered to victims; therefore, the target detection limit for these compounds in biological samples is 10 ng/mL. Currently these compounds are predominantly analyzed using immunoassay techniques; however more specific screening methods are needed. The goal of this dissertation was to develop a rapid, specific screening technique for benzodiazepines in urine samples utilizing surface-enhanced Raman spectroscopy (SERS), which has previously been shown be capable of to detect trace quantities of pharmaceutical compounds in aqueous solutions. Surface enhanced Raman spectroscopy has the advantage of overcoming the low sensitivity and fluorescence effects seen with conventional Raman spectroscopy. The spectra are obtained by applying an analyte onto a SERS-active metal substrate such as colloidal metal particles. SERS signals can be further increased with the addition of aggregate solutions. These agents cause the nanoparticles to amass and form hot-spots which increase the signal intensity. In this work, the colloidal particles are spherical gold nanoparticles in aqueous solution with an average size of approximately 30 nm. The optimum aggregating agent for the detection of benzodiazepines was determined to be 16.7 mM MgCl2, providing the highest signal intensities at the lowest drug concentrations with limits of detection between 0.5 and 127 ng/mL. A supported liquid extraction technique was utilized as a rapid clean extraction for benzodiazepines from urine at a pH of 5.0, allowing for clean extraction with limits of detection between 6 and 640 ng/mL. It was shown that at this pH other drugs that are prevalent in urine samples can be removed providing the selective detection of the benzodiazepine of interest. This technique has been shown to provide rapid (less than twenty minutes), sensitive, and specific detection of benzodiazepines at low concentrations in urine. It provides the forensic community with a sensitive and specific screening technique for the detection of benzodiazepines in drug facilitated assault cases

Is Forensic Paint Analysis Affected by Environmentally Friendly Products?

The forensic comparison of paint often provides key evidence in crime scene investigations. Paint analysis involves using attenuated total reflectance infrared spectroscopy (ATR-FTIR) to compare the chemical makeup of different chips of paint. Environmentally friendly paints are becoming more common in homes, and this study was conducted to determine if the brand ECOS Paints, which absorbs potentially harmful compounds from the air, changes its chemical makeup over time. ECOS Paints claims that its products are uniquely formulated without the harsh chemicals that can be found in other paint brands. The company claims that its paints have a molecular sieve designed to stop harmful compounds from being released into the air (Air Pure Learn). Four paints were chosen from ECOS Paints, the air-purifying primer, air-purifying drywall primer, anti-formaldehyde paint, and the air-purifying paint. The paint was applied to wood sticks in two coats and every two weeks the paint was analyzed using ATR-FTIR to determine if there was a change in the chemical makeup. These results will be presented at the conference

Plastic Water Bottles, Source of Phthalates?

Phthalates are plasticizers which are added to many materials to increase their flexibility, durability, longevity, and transparency. These compounds are commonly found in personal-care products, plastic bottles, medical tubing, and in foods (Centers for Disease Control, n.d). Due to their prevalence in our everyday lives, and their ability to act as endocrine disruptors in humans, knowing the exact source of phthalate exposure is of interest to public health. One common source is the contact between food we consume and the plastic containers they are stored in. This study was conducted to determine thepresence of phthalates in disposable water bottles after incubation at three different temperatures to determine the optimal storage temperature that would expel the least amount of phthalates. Over the course of eight weeks, water bottles were incubated at 4°C, 29°C, and 40°C. The water samples from each condition were extracted every two weeks to detect the level of dimethyl phthalate (DMP), using high performance liquid chromatography (HPLC) with UV detection. The relative concentration was then plotted over time. It was hypothesized that water stored at higher temperatures would have higher levels of DMP compared to water stored in colder temperatures (Al-Saleh, 2011). However, we found that bottled water stored at higher temperatures over the course of eight weeks contained lower levels of DMP over time compared to bottled water stored at cooler temperatures. The phthalate levels obtained were low, however these chemicals should still not be dismissed due to the health issues which could arise from exposure

Personal Care Products: Where are the Phthalates?

Phthalates are chemicals that are commonly used as a plasticizer in personal care products. This class of compounds is added to help prevent products from drying out. Phthalates have been shown to have potential negative impacts on reproductive organs, cause birth defects, effect the endocrine system, as well as causing other ill effects. For example, previous work found that phthalates can have an effect on the endocrine system of adolescent individuals. In an intervention study, phthalate exposure was reduced when these products were not being used. The purpose of the present study is to examine phthalate abundance in personal care products and to design an intervention study to lessen exposure. To identify products containing phthalates, we used the Environmental Working Group’s Skin Deep cosmetic database. This database contains personal care products and their ingredients. We used the database to identify products that contain phthalates and the type of phthalates used. The most commonly used phthalate is polyethylene terephthalate, with it currently found in 610 products, with 314 of which are nail polish. There are also 12 other kinds of phthalates that are regularly used in personal care products, ranging from lipstick to sunscreen. We can see that there are still a multitude of products that contain potentially harmful phthalates. This study is the foundation to future work looking at exposure to phthalates in adult populations and assessing sources of exposure from personal care products

Personal Care Products: Where are the Phthalates?

Phthalates are chemicals that are commonly used as a plasticizer in personal care products. This class of compounds is added to help prevent products from drying out. Phthalates have been shown to have potential negative impacts on reproductive organs, cause birth defects, effect the endocrine system, as well as causing other ill effects. For example, previous work found that phthalates can have an effect on the endocrine system of adolescent individuals. In an intervention study, phthalate exposure was reduced when these products were not being used. The purpose of the present study is to examine phthalate abundance in personal care products and to design an intervention study to lessen exposure. To identify products containing phthalates, we used the Environmental Working Group’s Skin Deep cosmetic database. This database contains personal care products and their ingredients. We used the database to identify products that contain phthalates and the type of phthalates used. The most commonly used phthalate is polyethylene terephthalate, with it currently found in 610 products, with 314 of which are nail polish. There are also 12 other kinds of phthalates that are regularly used in personal care products, ranging from lipstick to sunscreen. We can see that there are still a multitude of products that contain potentially harmful phthalates. This study is the foundation to future work looking at exposure to phthalates in adult populations and assessing sources of exposure from personal care products

The Impact of Unplanned Remote Instruction on a CURE Paired with Cookbook-Style Laboratory Exercises

Course based-undergraduate research experiences (CUREs) have been well defined in the literature. These authentic research experiences can be designed in many different ways, ranging from fully faculty-guided to completely student-driven (Spell et al., 2014). The implementation of CUREs is growing within biology education because they have been shown to provide collaborative environments that foster engagement with the scientific process, while promoting iterative research through the process of discovery (Auchincloss et al., 2014). Due to the COVID-19 pandemic, the semester-long CURE developed by our group experienced a rapid transition to remote instruction, creating a pseudo-experimental condition to compare student performance across semesters in on-campus versus remote learning conditions. In this semester-long set of laboratory modules, students develop skills to assess exposure to environmental chemicals. As originally designed, students participate in hands-on cookbook-style labs to learn about sample extraction methods and are introduced to the CURE-project, which entails authentic sample extraction, data analysis, and presentation of a poster. Rather than completing the full set of modules, the COVID-19 cohort completed the canned labs, but were tasked with virtually viewing the experimental process and analyzing previously collected data. Previous work by Kirkpatrick et al. (2019), has determined that there was no significant difference in the positive impacts on students’ attitudes between students who completed a computer-based CURE versus a bench-based CURE. This study examines if that holds true when the same research project is taken to a remote format

\u3ci\u3eDrosophila\u3c/i\u3e Model for Potential Plasticizer Induced Hyperactivity

Plasticizing additives such as phthalates, are known to cause disruptions in human nervous systems linked to neurological disorders, thus with the Drosophila activity monitoring (DAM) system test can be conducted to consider whether the flies are exhibiting hyperactivity (Hlisníková et al., 2021). Drosophila is a useful model for exposure of metabolic compounds followed by general and specific assays of their effects. Our experiments propose a link between exposure to phthalates and hyperactivity between humans that can be investigated with flies as a model for testing hyperactivity (Praveena et al., 2020). The link that is proposed is a cross-sectional study that collected urine samples of children and then scored kids based on attention-deficit/hyperactivity disorder (ADHD) (Kim et al., 2009). The DAM system is a method in which flies are individually monitored for activity during the day and night to notice any differences in general activity, locomotion, and circadian rhythms. The general activities of the flies would be examined alongside a baseline of Drosophila activity, alongside flies induced with glucose to measure any differences in hyperactivity. The addition of glucose is to give a baseline of what hyperactive flies will look like in their sleep cycle and movements in the DAM system We hypothesize a significant increase in hyperactivity in phthalate-exposed flies over both high-glucose and normal flies because phthalates are disrupters in the nervous system, thus may cause signs of hyperactivity when administered to the flies