137 research outputs found
Bi2O3/Nylon multilayered nanocomposite membrane for the photocatalytic inactivation of waterborne pathogens and degradation of mixed organic pollutants
No full textWorldwide there is an increasing demand for clean water and sanitation systems and any different solutions are under evaluation, including advanced oxidation processes such as photocatalysis. This work describes the scalable synthesis process of an electrospun composite membrane made of Nylon and embedded α/β-Bi2O3 nanoparticles that can be activated by visible light instead of UV light typically used with other nanomaterials (e.g. TiO2). As a proof of concept, the efficacy of the α/β-Bi2O3 electrospun composite membrane in the visible light inactivation of pollutants and pathogens was demonstrated in a Continuous-flow Photocatalytic Membrane Reactor, highlighting the great potential of this advanced photocatalytic process for clean water and sanitation
The Identification of Selective Pathogenic Microbial Community Biofilms in Different Distribution Pipeline Materials and Their Disinfection Kinetics
No full textBiofilms in water distribution lines strongly affect water safety as they are the main carriers of pathogens. The current study investigated the biofilm formation and identification of selected pathogens in different distribution pipeline materials and their disinfection method in an annular reactor (AR). Initially, the quality of the flowing water from each pipeline material was analyzed, i.e., pH, TDS, EC, turbidity, and salinity; then, the biofilm formation was monitored for each material, i.e., ABS, PC, PVC, PP, and HDPE. Further, the disinfection kinetics of biofilm at different chlorine doses, i.e., 0.5, 1.0, 1.5, and 2.0 mg/L, was investigated. The selected pathogens, i.e., E. coli, Pseudomonas, Shigella, Salmonella sp., and Vibrio sp. were identified in biofilms formed in different pipeline materials. The disinfection kinetics results showed that a chlorine dose of 2.0 mg/L was the most effective in disinfecting selected pathogens. Following the disinfection kinetics, it was observed that Salmonella sp. was disinfected within 7 days, whereas other pathogenic biofilms were disinfected within 14 days. The efficacy of chlorine disinfection was affected by the types of pipeline materials. The study outcomes could provide insights into biofilms' disinfection method and the selection of suitable pipeline materials to ensure drinking water safety
Photocatalytic Denitrification of Nitrate Using Fe-TiO2-Coated Clay Filters
No full textIn this work, 3D-structured clay filters were prepared and coated with iron-doped titanium dioxide (Fe-TiO2) using 3D printing and sol–gel soaking and calcination techniques. Three-dimensional printing was employed to mold and shape the clay filters before annealing. The coated and uncoated filters were characterized for different properties, i.e., morphology, optical properties, and crystalline structure, using field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDS), UV/Vis diffused reflectance spectroscopy (DRS), and X-ray diffraction (XRD). The FESEM images show uniform coatings of round-shaped Fe-TiO2 on the tiny pore of the clay filter. The optical energy band gap of the obtained coating was around 2.8 eV, estimated by Tauc’s plot, compared with 3.2 eV of pristine anatase TiO2. The XRD spectra data processed through XRD software revealed the coatings of TiO2 on the filter surface with the obtained phase of anatase. The photocatalytic performance of bare and coated filters was initially tested for the degradation of indigo carmine (IC) dye and the obtained results suggested the photocatalytic degradation of IC dye by the Fe-TiO2 clay filter compared with the bare filter. Afterward, the denitrification of nitrate NO3 at various concentrations was performed using Fe-TiO2-coated clay filters and analyzing the total nitrogen (TN) analysis and reduction of NO3 to nitrite (NO2−), nitrogen monoxide (NO), and nitrogen gas (N2). The TN analysis revealed up to 81% denitrification efficiency of the 30 ppm NO3 solution with the photocatalytic response of the Fe-TiO2-coated filter. The results revealed that the Fe-TiO2-coated clay filter has a high potential for denitrification applications under natural sunlight
Food waste measurement toward a fair, healthy and environmental-friendly food system: a critical review
No full textPurpose–Given the importance of food waste in the economic, social, health and environmental dimensions,the purpose of this work is to detect, through a systematic and configurative literature review on food-waste-measurement methodologies, the global approaches, characteristics, limitations, opportunities and resultsapplied within the literature. The analysis of these papers provides useful information about how far we arefrom international action plans and, therefore, how we need to direct programs and policies to measure andreduce food waste and ensure food security and food safety.
Design/methodology/approach–The authors have conducted a systematic, configurative literature reviewon food waste measurement methodologies applied only within empirical studies published in academic peer-reviewed scientific journals. Based on the Commission Delegated Decision (EU) 2019/1597 of May 3, 2019(OJEU, 2019) regarding common methodologies and minimum quality requirements for the homogeneousassessment of food waste quantities and composition, the authors investigated the issue on Web of ScienceCore Collection (WoS) from June 2000 to June 2020. The authors researched keywords within article titles,abstracts and author keywords by utilizing 34 different research strings.
Findings–The proposed review particularly refers to following topics: measurement methodologies appliedaccording to the Commission Delegated Decision (EU) 2019/1597; editorial placement and publication timeline;geographical area; food supply-chain stage and publication journals; and the main features, limitations,opportunities and results for each measurement methodology as presented by authors. Among the first 48,000results, only 58 academic articles are perfectly in line with the aim of the review, highlighting the lack ofstandardized methodologies, the limits of those proposed and the deficiency of comparable results to achievesustainable international goals.
Originality/value–The proposed review is one of the few concerning food waste measurementmethodologies. Food waste measurement is essential to rebalance the actual inadequate food system and toswitch it toward a fair, healthy and environmentally friendly one, thereby (1) managing the human nutritionsystem paradox of hungry, undernourished and over-weight people; (2) reducing food insecurity; (3) ensuringeach living being’s access to healthy, nutritious and sustainable food; and (4) reducing environmental impacts(neutral or positive impact) and the loss of biodiversity and mitigating climate change
Efficient and Rapid Combined Electrocoagulation–Filtration of Arsenic in Drinking Water
No full textArsenic (As) contamination is a severe problem in drinking-water sources. This study
designed and investigated a novel combined electrocoagulation–filtration (ECF) system to investigate
As treatment and filtration in drinking water in collaboration with HANDS-Pakistan and Medico
International, Germany. Two separate pilot-scale ECF systems were designed and developed with an
electrocoagulation (EC) unit and a commercially available PAUL® filter configured with vertical flatsheet ultra-low-pressure membranes of 0.04 μm pore size for the combined treatment and filtration
of different As concentrations. Real drinking water at different As concentrations, i.e., 100, 200, and
300 μg/L were tested on one ECF system with EC electrodes of iron (Fe) and another system with
aluminum (Al), at different treatment times (0, 5, 10, 20, 45, 60, 120, 180 min), at a fixed current density
(12 mA/cm2
) and water flow rate of 1 L/min. The initial results showed 99% As removal within
5 min with the combined ECF treatment for both electrodes of Fe and Al. In addition, the effect of
ECF on different water-quality parameters and the ionic interference on ECF performance and As
filtration were analyzed. The results showed the promising potential of combined ECF treatment and
filtration for treating and purifying A
Spectral correspondences for finite graphs without dead ends
No full textBux K-U, Hilgert J, Weich T. Spectral correspondences for finite graphs without dead ends. Indagationes Mathematicae . 2025;36(1):188-217.We compare the spectral properties of two kinds of linear operators characterizing the (classical) geodesic flow and its quantization on connected locally finite graphs without dead ends. The first kind are transfer operators acting on vector spaces associated with the set of non-backtracking paths in the graphs. The second kind of operators are averaging operators acting on vector spaces associated with the space of vertices of the graph. The choice of vector spaces reflects regularity properties. Our main results are correspondences between classical and quantum spectral objects as well as some automatic regularity properties for eigenfunctions of transfer operators. (c) 2024 The Author(s). Published by Elsevier B.V. on behalf of Royal Dutch Mathematical Society (KWG). This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)
Health Hazard Evaluation Report: HETA-83-275-1394: Kautt and Bux MFG.; Mundelein, Illinois
No full textWorker exposures to asbestos (1332214), copper (7440508) dust, and 1,1,1-trichloroethane (71556) (TCE) were investigated on June 15, 1983, at Kautt and Bux Manufacturing (SIC-3621) in Mundelein, Illinois. The evaluation was requested by District 140, International Association of Machinists and Aerospace Workers Union, on behalf of 14 exposed production workers. Personal and area air samples were collected and analyzed for asbestos, copper dust, and TCE. Selected workers were questioned about any work-related health problems. All asbestos concentrations were below the OSHA limit of 350ppm. For copper dust, concentrations ranged from 0.007 to 0.012 milligrams per cubic meter (mg/m3), compared to the OSHA limit of 1mg/m3. None of the workers questioned reported any job-related health symptoms. The author concludes that no hazard exists from TCE or copper dust, but a hazard from asbestos does exist. The author recommends use of engineering controls or additional personal protective equipment during the filling of 55-gallon drums with asbestos reinforced plastic pellets, use of a vacuum with a High Efficiency Particulate Air filter to clean up excess asbestos reinforced plastic shavings, and prohibition of eating, drinking, and smoking at workstations
How Do Neural Networks Enhance the Predictability of Central European Stock Returns?
No full textIn this paper, the author applies neural networks as nonparametric and nonlinear methods to Central European (Czech, Polish, Hungarian, and German) stock market returns modeling. In the first part, he presents the intuition of neural networks and also discusses statistical methods for comparing predictive accuracy, as well as economic significance measures. In the empirical tests, he uses data on the daily and weekly returns of the PX-50, BUX, WIG, and DAX stock exchange indices for the 2000–2006 period. He finds neural networks to have a significantly lower prediction error than the classical models for the daily DAX series and the weekly PX-50 and BUX series. The author also achieves economic significance of the predictions for both the daily and weekly PX-50, BUX, and DAX, with a 60% prediction accuracy.emerging stock markets, predictability of stock returns, neural networks
Governance of coal resources in the Sindh province (SE-Pakistan): an evaluation of challenges and reforms
No full textAbstract Pakistan is endowed with immense mineral resources, particularly soft coal (lignite) deposits in the Sindh province (SE-Pakistan), which boast an estimated 185 Gt, with a significant portion of approximately 175 Gt located in the Thar region. These deposits have the potential to address the country’s energy crises, drive economic growth, support urbanization and alleviate poverty. However, Thar’s coal remains considerably underutilized, as evidenced by its minimal contribution to Pakistan’s minerals-to-GDP ratio. This raises pressing questions: how can Pakistan fully leverage its significant coal potential? And what strategies can Pakistan adopt to maximize substantial foreign direct investment in the coal mining sector? To address this, Pakistan’s mineral policy and governance system is critically examined, with a particular focus on province Sindh’s regulatory framework governing coal, concerned social and environmental obligations and mining operations. The research seeks to identify weaknesses within the existing policy and regulatory framework governing Sindh’s coal sector and proposes actionable reforms centered on transparency, inclusivity and sustainability, with the aim of establishing a sustainable coal governance system for long-term economic growth in Pakistan. The study concludes that regulatory fragmentation, outdated geological data, lack of investor protection and insufficient community engagement are major barriers to sectoral growth and foreign investment. A comprehensive and cohesive “National Thar Coal Policy” is urgently needed to streamline inter- and intra-agency coordination, enhance transparency in licensing and institute robust social and environmental safeguards. Implementing these reforms will improve investor confidence, promote responsible resource development and help realize the full economic potential of Pakistan’s coal sector while ensuring long-term sustainability and socio-economic benefits
MANAGEMENT OF GEODIVERSITY AND GEOSYSTEM SERVICES IN GEOPARKS: A CASE STUDY OF THE CHABLAIS UNESCO GLOBAL GEOPARK, FRANCE
No full text- …
