Origination of Radon-222 (222Rn) from soil and its concentration, contributing to the highest exposure of ionizing radiation to the public is natural. It is a known radioactive gas and its percentage ...in concentrations contributing to outdoor radon atmospheric level depends on some physical parameters of the soil. To ascertain some of its dependency on soil porosity, a radiometric survey was carried out on soil depths at varying locations and the laboratory analysis was carried out on the soil sample at each location and depth in order to determine its porosity. The measurements were done using radon detector at five (5) locations. At each location, data were collected at four (4) different soil depths of 20, 40, 60 and 100 cm respectively. In addition, soil samples at these locations and depths were taken to the laboratory for porosity test. The result showed that highest value of 222Rn concentration at 100 cm depth is 24680 ± 1960 Bqm−3 with maximum porosity level of 69.92%, while the lowest concentration at 100 cm depth is 7370 ± 1139 Bqm−3 with minimum porosity level 51.61% respectively. Inferentially, a statistical analysis carried out using Pearson correlation showed that there exist some relationships between soil-gas 222Rn concentrations measured and soil porosity determined at each measurement soil-depths. The nature of the established relationship shows interdependency of 222Rn on soil porosity at different depths, such that if the soil porosity is known, its corresponding soil-gas radon concentration can be determined.
Infiltration and/or inflow (I/I) into a collection system often causes hydraulic overloads at the associated treatment plant. The impacts from I/I can become especially severe in areas with unstable ...soil conditions and deteriorating sewer systems. I/I can (a) result in increased operation and maintenance costs and (b) cause overflows and bypasses of untreated wastewater within the collection system during wet weather conditions. A major reason for I/I flows is improper installation and degradation of privately owned sewer lines as well as illegal or improper private connections. Previous studies have indicated that a large percentage of I/I flows are the result of defective sewer lines on private property. This article presents a computer model that has been developed as a comparison and/or decision-making tool to predict the reduction of sanitary sewer overflows and private property I/I for various rehabilitation approaches.
Herein, fatty acid (oleic acid, OA) was upgraded to fatty acid methyl ester (FAME)
via
esterification reaction using sulfonated biochar obtained from eucalyptus tree shed bark as solid acid catalyst. ...Under the optimal esterification conditions (
i.e.
, at 65 °C for 2 h using a methanol/OA molar ratio of 10 : 1 with a catalyst dosage of 4 wt%), the FAME yield was 97.05 ± 0.28% when a solid acid catalyst prepared by loading 6 g of
p
-Toluenesulfonic acid (
p
-TSA) on 2 g of activated biochar (
p
-TSA
3
/ABC) was used. The remarkable performance of the
p
-TSA
3
/ABC could be attributed to its high acidity (468.8 μmol g
−1
) and dominance of the SO
3
H acid site on the catalyst surface. Experimental findings showed that the
p
-TSA
3
/ABC was relatively stable due to its highly functionalized structure. The catalyst was recycled for five successive cycles and exhibited no dramatic decrease in catalytic activity.
Herein, fatty acid (oleic acid, OA) was upgraded to fatty acid methyl ester (FAME)
via
esterification reaction using sulfonated biochar obtained from eucalyptus tree shed bark as solid acid catalyst.
In this study, the surface sediments of the Malacca and Prai Rivers were analyzed to identify the distributions, and sources of Polycyclic Aromatic Hydrocarbons (PAHs). The total PAH concentrations ...varied from 716 to 1210 and 1102 to 7938 ng g(-1)dw in the sediments of the Malacca and Prai Rivers, respectively. The PAH concentrations can be classified as moderate and high level of pollution in the sediments of the Malacca and Prai Rivers, respectively. The comparison of PAHs with the Sediment Quality Guidelines (SQGs) indicates that the PAHs in the sediments of the Malacca and Prai Rivers may have the potential to cause adverse toxicity effects on the sampled ecosystems. The diagnostic ratios of individual PAHs indicate both petrogenic- and pyrogenic-origin PAHs with dominance of pyrogenic source in both rivers. These findings demonstrate that the environmental regulations in Malaysia have effectively reduced the input of petrogenic petroleum hydrocarbons into rivers.
Abstract
Herein, esterification of oleic acid (OA) over tosylic acid functionalized eucalyptus bark biochar (TsOH-MBC) to synthesize fatty acid methyl ester (FAME) was investigated. The TsOH-MBC ...catalyst was prepared via pyrolysis-activation-sulfonation process at various impregnation ratios and was characterized by SEM, FTIR, EDX, XRD, BET, TGA and acid site density techniques. The catalytic performance of the sulfonated biochar catalyst was described in terms of acidity and FAME yield. 6 g of sulfonic acid loaded on 10 g of MBC (6TsOH-MBC) appeared to be most appropriate combination to achieve a highly active catalyst for the esterification of OA with 96.28% conversion to FAME at 80 °C for 5 h with catalyst loading of 4.0 wt% and 8:1 methanol/OA molar ratio. The catalytic reaction kinetic data were very well described by the second-order model, with a rate coefficient of 0.223 mL mol
−1
h
−1
at 80 °C and activation energy of 81.77 kJ mol
−1
. The thermodynamic parameters such as
$$\Delta H$$
Δ
H
,
$$\Delta S$$
Δ
S
and
$$\Delta G$$
Δ
G
were determined to be 78.94 kJ mol
−1
, 135.3 J mol
−1
K
−1
and 33.03 kJ mol
−1
, respectively. This research provided an environmentally friendly procedure for FAME production that could be replicated on a commercial scale.
Objectives: This study explored the prevalence and predictors of alcohol and cannabis co-use among 9263 Filipino adolescents, using data from the 2019 Global School-based Student Health Survey ...(GSHS). Methods: We conducted a cross-sectional secondary analysis of the GSHS, targeting adolescents aged 13-17 years and excluding cases with incomplete data on alcohol and cannabis use. Our analysis employed the bivariate chi-square test of independence and multivariable logistic regression using Stata version 18 to identify significant predictors of co-use, with a p-value threshold set at 0.05. Results: The weighted prevalence of co-users was 4.2% (95% confidence interval CI, 3.4 to 5.3). Significant predictors included male sex (adjusted odds ratio aOR, 4.50; 95% CI, 3.31 to 6.10; p<0.001) and being in a lower academic year, specifically grade 7 (aOR, 4.08; 95% CI, 2.39 to 6.99; p<0.001) and grade 8 (aOR, 2.20; 95% CI, 1.30 to 3.72; p=0.003). Poor sleep quality was also a significant predictor (aOR, 1.77; 95% CI, 1.29 to 2.44; p<0.001), as was a history of attempted suicide (aOR, 5.31; 95% CI, 4.00 to 7.06; p<0.001). Physical inactivity was associated with lower odds of co-use (aOR, 0.45; 95% CI, 0.33 to 0.62; p<0.001). Additionally, non-attendance of physical education classes (aOR, 1.48; 95% CI, 1.06 to 2.05; p=0.021), infrequent unapproved parental checks (aOR, 1.37; 95% CI, 1.04 to 1.80; p=0.024), and lower parental awareness of free-time activities (aOR, 0.63; 95% CI, 0.45 to 0.87; p=0.005) were associated with higher odds of co-use. Factors not significantly linked to co-use included age group, being in grade 9, always feeling lonely, having no close friends, being bullied outside school, and whether a parent or guardian understood the adolescent's worries. Conclusions: The findings highlight the critical need for comprehensive interventions in the Philippines, addressing not only physical inactivity and parental monitoring but also focusing on sex, academic grade, participation in physical education classes, sleep quality, and suicide attempt history, to effectively reduce alcohol and cannabis co-use among adolescents.
•Characterization and possible applications of waste biomass ash from oleoresin industries.•Acid treatment yields high surface area material suitable as adsorbent.•Magnetic separation affords iron ...rich fraction with excellent surface area.•Ash suitable as fertilizer and cement substitute after pretreatment.•Rich in carbon which could be recovered and used as adsorbent for pollutants and as additive in rubber composites.
The oleoresin industries in India make use of the spice residue as boiler fuel and the combustion of this waste biomass generates tons of ash everyday. Herein the study we have carried out the characterization of this industrial waste ash in order to have a broad awareness of its properties in terms of toxicity, composition and possible utility. Techniques like XRF, ICP-AES, SEM–EDS, surface area, pore volume analysis, powder XRD, TG–DTA, FTIR and elemental analyses were used for the purpose. Ash collected from the grate fired furnace (bottom ash) as well the flyash deposited on the boiler walls and pipes were analyzed. Elemental analysis of the ashes indicates its potential as a crude fertilizer or cement replacement material. PXRD indicates the presence of several crystalline phases such as harrisonite (Ca(Fe3+,Mg)6(PO4)2(SiO4)2), aphthitalite ((K,Na)3Na(SO4)2, cryptomelane (KMn4+6Mn2+2O16), varulite (NaCaMn2+2.25Fe2+0.5Fe3+0.25(PO4)3), marokite (CaMn2O4), fersilicite (FeSi) in the flyash fraction and the phases magnetite (Fe3+2Fe2+O4), kalsilite (KAlSiO4), cryptomelane (KMn4+6Mn2+2O16), fukuchilite (Cu3Fe2+S8), walthierite (Ba0.5Al3(SO4)2(OH)6), and magnesite (Mg(CO3) in furnace ash. The amorphous nature of silica in the ashes is evident from the characteristic broad hump around 2θ=30. The iron rich fraction of the ash consists primarily of magnetite which leads to a greenish blue color on heating the ash above 650°C. This magnetite fraction if separated could find use as catalysts in organic reactions. SEM images indicate the ashes to be highly agglomerated and EDX data shows the surface of the ash particles covered with potassium oxide and carbon. The percentage of K seems to be higher in the flyash due to the volatility of the potassium compounds which is carried up by the air current. Even though the surface area of the as received ashes is negligible an acid treatment removes the surface adsorbed species and increases the surface area to 368m2/g making it an effective adsorbent.
Aims At the core of medical diagnosis lies specific blood tests, urine analysis, microscopic and histologic examination of tissues, and as well radiological investigations that are usually ...confirmatory of the presence of a disease. However, the diagnosis of ADHD currently relies on reports of clinical symptoms which is usually subjective, with variable interpretations by different professionals, thus posing issues of misdiagnosis and reliability. This study set out to explore, appraise and summarize molecular biomarkers in literature over the past 30 years, which can be applied for the diagnosis of ADHD. Attention-deficit/hyperactivity disorder (ADHD) is a common neuropsychiatric and neurobehavioral disorder that affects children and adolescents, and more recently, gaining recognition in adults. It is characterized by a pervasive pattern of inattention, hyperactivity, and impulsivity or a mixture of the three, that cuts across the individual's multiple domains of life. Methods One-thousand articles collated across multiple sources and databases were systematically reviewed and analysed for this project. The keywords for the search criteria in the Boolean operators are “biomarkers and ADHD”, “molecular biomarkers and ADHD” and “biomarkers and ADHD and Diagnosis”. Results 5.6% of the articles from several types of studies were included in the final analysis after the inclusion and exclusion criteria were applied. The results revealed various heterogeneity across age, gender, ethnicity, medication status, comorbidities, and study type, in applying biomarkers to assist in the diagnosis of ADHD. Genetics and epigenetics studies were the most common type of molecular biomarkers studied and identified, accounting for 25% of the results. 80% of the studies analysed blood samples with a few others focusing on saliva, urine, cerebrospinal fluid, hair, and stool samples. All the studies identified focused on diagnostic biomarkers with 25% of them combining either prognostic or response-monitoring subtypes of biomarkers. Conclusion This study identified several potential molecular biomarkers in ADHD. However, most of the results showed only associations between the findings and the diagnosis/occurrence of ADHD. It remains a scientific goal to identify a specific and reliable biomarker for ADHD to assist psychiatrists in making accurate diagnosis. Lastly, it would be pragmatic to explore other types of biomarkers such as radiologic and electro-neurologic markers; given that diagnosis is a constellation of signs and symptoms together with appropriate tests. Combining them logically would increase the specificity of diagnosis of ADHD. This study was completed in partial fulfilment of Master of Science (MSc) in Clinical Psychiatry with the University of South Wales.
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