Seasonal Variation and Source Apportionment of Inorganic and Organic Components in PM2.5: Influence of Organic Markers Application on PMF Source Apportionment

PM2.5 samples collected over a 1-year period in a Chinese megacity were analyzed for organic carbon (OC), elemental carbon (EC), water soluble ions, elements and organic markers such as polycyclic aromatic hydrocarbons (PAHs), hopanes, steranes, and n-alkanes. In order to study the applicability of organic markers in source apportionment, this study analyzes the relationship between organic and inorganic components, and four scenarios were implemented by incorporating different combinations of organic and inorganic tracers. A positive correlation of SO42− with 4 rings PAHs can prove that coal burning directly emits a portion of sulfate. A positive correlation of NO3− with 5-7 rings PAHs are found, implying collective impacts from the vehicle source. The concentrations of OC and EC positively correlate with the 5-7 rings PAHs and Cu and Zn, which proves that part of Cu and Zn comes from vehicle emissions. Five factors were identified by incorporating only conventional components, including secondary source (SS, 30%), urban fugitive dust (UFD, 14%), cement dust (CD, 4%), traffic source (TS, 19%) and coal combustion (CC, 14%). Six factors were identified by incorporating conventional components and PAHs, including SS (28%), UFD (15%), CD (4%), CC (13%), gasoline vehicles (GV, 12%) and diesel vehicles (DV, 10%). Eight factors were identified by incorporating conventional components, PAHs, hopanes, and n-alkanes, including SS (26%), UFD (17%), CD (3%), GV (14%), DV (8%), immature coal combustion (ICC, 5%), mature coal combustion (MCC, 10%) and biogenic source (BS, 1%).

Anti-Blackness is the American Way: Assessing the Relationship Between Chattel Slavery, Lynchings, & Police Violence During the Civil Rights Movement

Research finds that historical anti-Black violence helps to explain the spatial distribution of contemporary conflict, inequality, and violence in the U.S. Building on this research, the current study examined the spatial relationship between chattel slavery in 1860, lynchings of Black individuals between 1882 and 1930, and anti-Black violence during the Civil Rights Movement era in which police or other legal authorities were implicated. I draw on an original dataset of over 300 events of police violence that occurred between 1954 and 1974 in the sample state of Louisiana, and that was compiled from a number of primary and secondary source documents that were themselves culled from archival research conducted in the state. Path analysis was then employed using negative binomial generalized structural equation modeling in order to assess the direct and indirect effects of these racially violent histories. The implications for social justice, public policy, and future research are also discussed. Keywords Slavery, lynchings, anti-Black violence, civil rights movement, police

Synthesis and Characterization of Feed-Grade Monocalcium Phosphate Ca(H2PO4)2·H2O from Oyster Shell

Oyster shells are considered as a byproduct or solid waste in mariculture or related food processing areas that face a major disposal problem at the landfill in coastal regions for sustainable development. Oyster shell is composed mostly of CaCO3, and it is also considered as a secondary source of calcium for various applications. In this paper, we extracted the calcium carbonate from oyster shell and used it as the source of calcium for the preparation of feed-grade monocalcium phosphate (MCP). The investigation shows that the heavy metal contents in oyster shells as well as in the synthesized MCP are extremely low, and the synthesized product meets the requirements for the European Union (EU) maximum limits applied for feed additives. The XRD, TG, and IR data analyses confirmed that the synthesized product is monocalcium phosphate.

Design and Development of a Hybrid DC-DC Converter for Solar-Battery-Based Standalone Milk Vending Machine

Dairying has become a major secondary source of income for several rural families. The easily perishable nature of milk increases the spoilage of the product and reduces the dairy farms' productivity in rural areas due to power supply shortage issues. In order to overcome the inaccessibility of proper preservation strategies, this chapter proposed a hybrid DC-DC converter for a solar battery-powered milk vending machine. This proposed system can work continuously and provides an uninterrupted power supply to maintain the milk quality at an optimum level. Moreover, the proposed system utilized a novel converter to reduce the number of power conversion stages and compact the system. Besides, the proposed converter can achieve a higher gain ratio with fewer components. Furthermore, a proper algorithmic-based control scheme has been implemented to maintain effective power flow management. Finally, to verify the feasibility and performance of the system, detailed results are obtained at different dynamic conditions, and various case studies are presented in this chapter.

Assessing the Quality of Sources in Wikidata Across Languages: A Hybrid Approach

Wikidata is one of the most important sources of structured data on the web, built by a worldwide community of volunteers. As a secondary source, its contents must be backed by credible references; this is particularly important, as Wikidata explicitly encourages editors to add claims for which there is no broad consensus, as long as they are corroborated by references. Nevertheless, despite this essential link between content and references, Wikidata's ability to systematically assess and assure the quality of its references remains limited. To this end, we carry out a mixed-methods study to determine the relevance, ease of access, and authoritativeness of Wikidata references, at scale and in different languages, using online crowdsourcing, descriptive statistics, and machine learning. Building on previous work of ours, we run a series of microtasks experiments to evaluate a large corpus of references, sampled from Wikidata triples with labels in several languages. We use a consolidated, curated version of the crowdsourced assessments to train several machine learning models to scale up the analysis to the whole of Wikidata. The findings help us ascertain the quality of references in Wikidata and identify common challenges in defining and capturing the quality of user-generated multilingual structured data on the web. We also discuss ongoing editorial practices, which could encourage the use of higher-quality references in a more immediate way. All data and code used in the study are available on GitHub for feedback and further improvement and deployment by the research community.

An evaluation of the role of engineering and infrastructure in national development

The clamour for engineering and infrastructure in national development in all spheres of development is more in the developed nations but the responsibility is no less for the developing economies/nations. A lot of effort has been made in sustaining engineering and infrastructural development in Nigeria; still there are more deficiencies in the formalization. Therefore this paper contributes to effort of formalizing the role it play in the national development. The sources of data were mainly on secondary source which rely on much of literature review and the analysis was analytical. The finding reveals the role of engineering and infrastructure in national development and its sustainability. It also state that institution should be established to set a clear plans and rule for service provision, regulate and monitor service quality, coordinate engineering and infrastructural project efficiently and equitably in maintenance of the existing infrastructure. The paper concludes that the government is encouraged to show more commitment to engineering and infrastructure development than ever. It also states that good quality engineering and infrastructure is necessary to avoid bottlenecks and services disruption and to support a range of importance activities in the economy. It was recommended that government should ensure that the standard and policies relating to infrastructural development are addressed and handled holistically. And that effective evaluation of contracts, consulting and construction services of the required professionals should be put in place for proper implementation.

Assessing The Vulnerability Index Of Covid-19 Pandemic In India

The coronavirus (COVID-19) outbreak has created havoc all across the States and Union Territories (UTs) of India since its beginning on 30th January 2020. As of 1st January 2021, India has recorded 10,305,788 cases and 149,218 deaths from this deadly pandemic. It has been observed through the data; across states and UTs, the trend and pattern of this disease are not similar at all. There are many reasons for these dissimilarities which are categorized into indicators to assess the vulnerability in this study. We have examined vulnerabilities in 28 states and 8 UTs of India. Livelihood Vulnerability Index (LVI) has been applied with certain modifications to calculate the Vulnerability Index (VI). The figure resulting from the vulnerability assessment corresponds that the factors involved in the three-section exposure, sensitivity, and adaptive capacity had a significant impact on deciding the vulnerability of the population. The result identified the states and UTs which are more vulnerable and need more attention from the government and policymakers. The proposed method of study is unique in its sense as vulnerability index calculation is purely based on a secondary source of data and therefore has an expectation of a higher degree of practical application.

A Noise Control Method Using Adaptive Adjustable Parametric Array Loudspeaker to Eliminate Environmental Noise in Real Time

Long-term exposure to environmental noise is dangerous to human health. Therefore, there is an urgent need to suppress or eliminate environmental noise. Due to the limitation of environmental space, the use of reverse sound waves emitted by loudspeakers for noise elimination has been widely used in noise control. However, because of the omni-directionality of sound propagation, a traditional voice coil loudspeaker (VCL) is used as a secondary source (emission reverse sound wave). It is easy to increase the sound pressure in non-target areas and form significant acoustic feedback to the reference source. Therefore, we propose an online secondary path modeling method using an adjustable parametric array loudspeaker (PAL) based on ultrasounds to eliminate environmental noise in real time. According to the different distance of the target, the size of the PAL is adjusted adaptively to realize the noise control of different long-distance targets. The distribution of quiet areas is discussed. The experimental results showed that a PAL as a secondary source had the same noise reduction effect as a traditional VCL, but it had longer propagation distance, smaller sound feedback and a more regular and controllable distribution of quiet areas. These research findings have great potential for improving environmental noise and creating a quiet environment.

Pretreatment of Plastic Waste: Removal of Colorants from HDPE Using Biosolvents

Plastics recycling remains a challenge due to the relatively low quality of the recycled material, since most of the developed recycling processes cannot deal with the additives present in the plastic matrix, so the recycled products end up in lower-grade applications. The application of volatile organic solvents for additives removal is the preferred choice. In this study, pretreatment of plastic packaging waste to remove additives using biosolvents was investigated. The plastic waste used was high-density polyethylene (HDPE) with blue and orange colorants (pigment and/or dye). The first step was to identify the type of colorants present in the HDPE, and we found that both plastics presented only one colorant that was actually a pigment. Then, limonene, a renewable solvent, was used to solubilize HDPE. After HDPE dissolution, a wide range of alcohols (mono-, di-, and tri-alcohols) was evaluated as antisolvents in order to selectively precipitate the polymer and maximize its purity. The use of limonene as solvent for plastic dissolution, in combination with poly-alcohols with an intermediate alkyl chain length and a large number of hydroxyl (OH) groups, was found to work best as an antisolvent (1,2,3-propanetriol and 1,2,4-butanetriol), leading to a removal of up to 94% and 100% of the blue and orange pigments, respectively. Finally, three cycles of extraction were carried out, proving the capability of the solvent and antisolvent to be recovered and reused, ensuring the economic viability and sustainability of the process. This pretreatment provides a secondary source of raw materials and revenue for the recycling process, which may lead to an increase in the quality of recycled polymers, contributing to the development of an economical and sustainable recycling process.

Does Model Reflect on Reality? Exploring Beneish M Score on Selected Private Commercial Banks in Nepal

This research explores if possible fraudulent financial statement is present in private commercial banks in Nepal. This study examines the viability of Beneish M-score model in detecting probable earning manipulation considering the sample of 16 private commercial banks including the joint ventures. The published annual report (income statement and balance sheet) of the year 2018 and 2019 of respective banks are used as a secondary source of information. This research employs Beneish M-score equation and threshold value -2.22 as keys to analysis. The result shows even four banks are engaging in income manipulation, the Beneish model cannot identify the deception on the financial statement. Though the given model is suggested for manufacturing companies, the researcher has used it to explore the Banks—this is the limitation of this research. Further investigation of these tools combined with other fraud detection models is suggested to discover financial manipulation and relationship with the stock market return.