Life cycle assessment of geopolymer concrete: A Malaysian context

An electrochemical fuel cell contains first and second monolithic electrically conducting flow field-bipolar plate assemblies arranged essentially parallel to each other such that an inside surface of the first bipolar separator plate is facing an inside surface of the second bipolar separator plate, wherein the bipolar separator plates are electrically and mechanically connected by intervening layers that are directly bonded to each other. The fuel cells can be stacked between endplates and supplied with hydrogen and oxygen to generate electric power. An air cooled condenser for use with a fuel cell stack is composed of a porous foam condensing element and a porous foam cooling element. The condenser can be placed by a fuel cell stack for cooling purposes.U

Using elemental concentrations and dust loadings as metrics of human exposure to potentially toxic elements in kindergarten indoor dust

Due to the hand-to-mouth activities frequently observed among the youngest children, they are likely to ingest higher amounts of indoor dust than adults. Since pre-schoolers are prone to exposure to potentially toxic elements (PTEs) through the ingestion route, characterising human exposure within kindergarten microenvironments is paramount for children who spend considerable time in school. Ergo, a study encompassing five kindergartens in an industrial city was performed. Indoor dust samples were collected from the kindergartens. The present study reports dust metal concentrations and metal loadings to estimate indoor exposure to PTEs. Total concentrations of chromium (Cr), cobalt (Co), nickel (Ni), cadmium (Cd), arsenic (As) and lead (Pb) were determined by Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) in the of the <63 μm and <250 μm particle size fractions of the indoor dust. The results show that the elemental loadings vary widely among the different kindergartens but are consistently higher in the finer dust size fraction. Non-parametric analysis (Spearman's rank-order correlation) shows strong and significant (p<0.001) positive correlations between total dust loading - dust elemental loading. Relatively strong correlations were also obtained between elemental loadings and elemental concentrations, but the relationship is only significant for Ni and Pb. The strong correlation (rs= 0.73) between Pb concentration and dust Pb loading suggests that total dust loading has a greater influence on dust Pb loading. The results suggest a negligible influence of dust mass over the dust elemental loading for elements such as Cd, Co, Cr and As

The effects of lead sources on oral bioaccessibility in soil and implications for contaminated land risk management

Lead (Pb) is a non-threshold toxin capable of inducing toxic effects at any blood level but availability of soil screening criteria for assessing potential health risks is limited. The oral bioaccessibility of Pb in 163 soil samples was attributed to sources through solubility estimation and domain identification. Samples were extracted following the Unified BARGE Method. Urban, mineralisation, peat and granite domains accounted for elevated Pb concentrations compared to rural samples. High Pb solubility explained moderate-high gastric (G) bioaccessible fractions throughout the study area. Higher maximum G concentrations were measured in urban (97.6 mg kg−1) and mineralisation (199.8 mg kg−1) domains. Higher average G concentrations occurred in mineralisation (36.4 mg kg−1) and granite (36.0 mg kg−1) domains. Findings suggest diffuse anthropogenic and widespread geogenic contamination could be capable of presenting health risks, having implications for land management decisions in jurisdictions where guidance advises these forms of pollution should not be regarded as contaminated land

Linking oral bioaccessibility and solid phase distribution of potentially toxic elements in extractive waste and soil from an abandoned mine site: Case study in Campello Monti, NW Italy

Oral bioaccessibility and solid phase distribution of potentially toxic elements (PTE) from extractive waste streams were investigated to assess the potential human health risk posed by abandoned mines. The solid phase distribution along with micro-X-ray fluorescence (micro-XRF) and scanning electron microscopy (SEM) analysis were also performed. The results showed that the total concentrations of PTE were higher in <250 μm size fractions of waste rock and soil samples in comparison to the <2 mm size fractions. Mean value of total concentrations of chromium(Cr), copper (Cu), and nickel (Ni) in waste rocks (size fractions <250 μm) were found to be 1299, 1570, and 4010 mg/kg respectively due to the parent material. However, only 11% of Ni in this sample was orally bioaccessible. Detailed analysis of the oral bioaccessible fraction (BAF, reported as the ratio of highest bioaccessible concentration compared with the total concentration from the 250 μm fraction) across all samples showed that Cr, Cu, and Ni varied from 1 to 6%, 14 to 47%, and 5 to 21%, respectively. The variation can be attributed to the difference in pH, organic matter content and mineralogical composition of the samples. Non-specific sequential extraction showed that the non-mobile forms of PTE were associated with the clay and Fe oxide components of the environmental matrices. The present study demonstrates how oral bioaccessibility, solid phase distribution and mineralogical analysis can provide insights into the distribution, fate and behaviour of PTE in waste streams from abandoned mine sites and inform human health risk posed by such sites

Using oral bioaccessibility measurements to refine risk assessment of potentially toxic elements in topsoils across an urban area

Elevated concentrations of As, Cr, Cu, Ni, Pb, V and Zn in topsoils in Belfast, Northern Ireland have been found to exceed assessment criteria in the city and therefore may pose a risk to human health. Most generic assessment criteria (GAC) for potentially toxic elements (PTEs) in soils assume PTEs are 100% bioavailable to humans. Here we use in-vitro oral bioaccessibility testing using the Unified BARGE method (UBM) to measure what proportion of soil contamination dissolves in the digestive tract and therefore is available for absorption by the body. This study considers how PTE bioaccessibility in soils varies spatially across urban areas and refines human health risk assessment for these PTEs using site specific oral bioaccessibility results to present the first regional assessment of risk that incorporates bioaccessibility testing. A total of 103 urban soil samples were selected for UBM testing. Results showed low bioaccessible fraction (BAF) for the PTEs from geogenic sources: Cr (0.45–5.9%), Ni (1.1–46.3%) and V (2.2–23.9%). Higher BAF values were registered for PTEs from anthropogenic sources: As (8.0–86.9%), Cu (3.4–67.8%), Pb (9.1–106.2%) and Zn (2.4–77.5%). Graphs of bioaccessibility adjusted assessment criteria (BAAC) were derived for each urban land use type and PTE. These provide a visual representation of the significance of oral bioaccessibility when deriving BAAC and how this is affected by 1) dominant exposure pathways for each land use and 2) relative harm posed from exposure to PTEs via each pathway, allowing oral bioaccessibility research to be targeted to contaminants and pathways that most significantly impact risk assessment. Pb was the most widespread contaminant with 16.5% of sites exceeding the Pb GAC. Applying BAAC did not significantly change risk evaluation for these samples as many had Pb BAF>50%. In contrast, all samples that exceeded the As GAC were found to no longer exceed a minimal level of risk when oral bioaccessibility was considered. Oral bioaccessibility testing resulted in a 45% reduction in the number of sites identified as posing a potential risk to human health

Looking behind the mask: social coping strategies of girls on the autistic spectrum

The socio-communication deficits of individuals on the autistic spectrum are well documented. However, this has largely been based on the male population and less is known about how females with autism manage social relationships across the developmental period. Ten adolescent female participants with a diagnosis of autism were interviewed and Interpretative Phenomenological Analysis used to explore their experiences of managing their social relationships. The results showed that participants were motivated to develop and maintain friendships, but during adolescence this became increasingly difficult. Consequently, they developed explicit strategies to manage these relationships, including masking and imitation. The use of such strategies was both advantageous and disadvantageous, and such findings should be considered in developing gender sensitive assessment and developmentally appropriate support

KSU Men\u27s Ensemble, KSU Community & Alumni Choir and KSU Chamber Singers, Illumination

KSU School of Music presents Illumination with KSU Men\u27s Ensemble, The Kennesaw State University Community and Alumni Choir and KSU Chamber Singers featuring John Rutter\u27s Gloria!https://digitalcommons.kennesaw.edu/musicprograms/1249/thumbnail.jp

Incorporating oral bioaccessibility into human health risk assessment due to potentially toxic elements in extractive waste and contaminated soils from an abandoned mine site

The waste rock, tailings and soil around an abandoned mine site in Gorno (northwest Italy) contain elevated concentrations of potentially toxic elements (PTE) exceeding the permissible limits for residential uses. Specifically, the maximum concentrations of As, Cd, Pb, and Zn were 107 mg/kg, 340 mg/kg, 1064 mg/kg, and 148 433 mg/kg, respectively. A site-specific human health risk assessment (HHRA) was conducted for residential and recreational exposure scenarios, using an approach based on Risk Based Corrective Action (RBCA) method, refined by incorporating oral bioaccessibility data. Oral bioaccessibility analyses were performed by simulating the human digestion process in vitro (Unified BARGE Method). Detailed analysis of oral bioaccessible fraction (BAF i.e. ratio of bioaccessible concentrations to total concentrations on 1) for 50% of the samples, indicating potential human health risks. This study provides information for site-specific risk assessments and planning future research