Water pollution caused by organic wastewater has become a serious concern worldwide. Fenton oxidation process is one of the most effective and suitable methods for the abatement of organic ...pollutants. However, the process has three obvious shortcomings: the narrow working pH range, the high costs and risks associated with handling, transportation and storage of reagents (H2O2 and catalyst), the significant iron sludge related second pollution. In order to overcome these shortcomings, various optimized Fenton processes have been widely studied. Therefore, a summary of the study status of Fenton optimization processes is necessary to develop a novel and high efficiency organic wastewater treatment method. Based on the optimization perspective, taking shortcomings of Fenton process as a breakthrough, the fundamentals, advantages and disadvantages of single Fenton optimization processes (heterogeneous Fenton, photo-Fenton and electro-Fenton) for organic wastewater treatment were reviewed and the corresponding reaction mechanism diagrams were drawn in this paper. Then, the feasibility and application of the coupled Fenton optimization processes (photoelectro-Fenton, heterogeneous electro-Fenton, heterogeneous photoelectro-Fenton, three-dimensional electro-Fenton) for organic wastewater treatment were discussed in depth. Additionally, the effect of some important operation parameters (pH and catalyst, H2O2, organic pollutants concentration) on the degradation efficiency of organic pollutants was studied to provide guidance for the optimization of operation parameters. Finally, the possible future research directions for optimized Fenton processes were given. The review aims to assist researchers and engineers to gain fundamental understandings and critical view of Fenton process and its optimization processes, and hopefully with the knowledge it could bring new opportunities for the optimization and future development of Fenton process.
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•Review of single Fenton optimization processes for organic wastewater treatment.•Review of coupled Fenton optimization processes for organic wastewater treatment.•Key operational parameters are discussed.•Insights into future research directions for optimized Fenton processes.
According to The Guardian, “Professors, programmers and journalists could all be out of a job in just a few years” 1. In North America, long before the pandemic, some high schools (both public and ...private) replaced books and notebooks with laptops. In universities, the students preferred listening to the recordings of the lectures taken on their computers or phones instead of actively taking notes during the classes. Technology has been the topic of many debates among teachers, parents, and students. Seen both advantageous and disadvantageous, technology in the classroom has become indispensable to teaching. Technology has proven to have been the only way out of the pandemic crisis regarding business and education. The trend in the education field in a post-pandemic context resulted from a blend between teaching approaches and technology use. However, in a post-pandemic context, this trend has been seen as one of the central factors leading to an increase in the lack of inperson socialization for youths and a principal distraction from their studies. Moreover, the development of more advanced software (A.I. Bot ChatGPT) has started to influence the teaching process regarding assignments. However, the real question is how and to what extent the use of technology can be advantageous for students today.
Background
Psychosis rates are higher among some migrant groups. We hypothesized that psychosis in migrants is associated with cumulative social disadvantage during different phases of migration.
...Methods
We used data from the EUropean Network of National Schizophrenia Networks studying Gene-Environment Interactions (EU-GEI) case-control study. We defined a set of 3 indicators of social disadvantage for each phase: pre-migration, migration, and post-migration.
Results
249 cases and 219 controls were assessed. Pre-migration (OR 1.61, 95%CI 1.06-2.44, p=0.027) and postmigration social disadvantages (OR 1.89, 95%CI 1.02-3.51, p=0.044), along with expectations/achievements mismatch (OR 1.14, 95%CI 1.03-1.26, p=0.014) were all significantly associated with psychosis. We found a dose-response effect between number of adversities across all phases and odds of psychosis (≥6: OR 14.09, 95%CI 2.06-96-47, p=0.007).
Conclusions
The cumulative effect of social disadvantages before, during and after migration was associated with increased odds of psychosis in migrants, independently of ethnicity or length of stay in the country of arrival. Public health initiatives that address the social disadvantages that many migrants face during the whole migration process and post-migration psychological support may be reduce the excess of psychosis in migrants.
Disclosure of Interest
None Declared
The demand for wireless communications is growing every day which requiresmore speed and bandwidth. In two way relay networks (TWRN), physical layer network coding (PLNC) was proposed to double the ...bandwidth. A TWRN is a system where two end users exchange data through a middle node called the relay. The two signals are allowed to be physically added before being broadcasted back to the end users. This system can work smoothly in flat fading channels, but can not be applied straightforward in frequency selective channels. In a multipath multi-tap FIR channel, the inter-symbol interference (ISI) spreads through several symbols. In this case, the symbols at the relay are not just an addition of the sent symbols but also some of the previous symbols from both sides. This not only causes a traditional PLNC to fail but also a simple one equalizer system will not solve the problem. Three main methods have been proposed by other researchers. The OFDM based PLNC is the simplest in terms of implementation and complexity but suffers from the disadvantages of the OFDMlike cyclic prefix overhead and frequency offset. The main disadvantage, however is the relatively low BER performance because it is restricted to linear equalizers in the PLNC system. Another approach is pre-filtering or pre-equalization. This method also has some disadvantages like complexity, sensitivity to channel variation and the need of a feedback channel for both end nodes. Finally, the maximum likelihood sequence detector was also proposed but is restricted to BPSK modulation and exponentially rising complexity are major drawbacks. The philosophy in this work is to avoid these disadvantages by using a time domain based system. The DFE is the equalizer of choice here because it provides a non-trivial BER performance improvement with very little increase in complexity. In this thesis, the problem of frequency selective channels in PLNC systems can be solved by properly adjusting the design of the system including the DFE. The other option is to redesign the equalizer to meet that goal. An AF DFE system is proposed in this work that provides very low complexity especially at the relay with little sensitivity to channel changes. A multi-antenna DNF DFE system is also proposed here with an improved performance. Finally, a new equalizer is designed for very low complexity and cost DNF approach with little sacrifice of BER performance. Matlab was used for the simulations with Monte Carlo method to verify the findings of this work through finding the BER performance of each system. This thesis opens the door for future improvement on the PLNC system. More research needs to be done like testing the proposed systems in real practical implementation and also the effect of adding channel coding to these systems.
This is an open access title available under the terms of a CC BY-NC-ND 4.0 License. It is free to read, download and share on Elgaronline.com. Achieving Equitable Education argues that critical gaps ...in education data are hampering the achievement of one of the UN’s Sustainable Development Goals: “inclusive and equitable quality education…for all”. This book critically explores education data gaps across regions, themes and levels of education, highlighting key relationships and disconnects between national, regional and global data needs.
•Composition and properties of biomass were summarised.•Comparative characterization between biomass and coal was given.•Advantages of biomass composition and properties were described.•Disadvantages ...of biomass composition and properties were discussed.
An extended overview of the advantages and disadvantages of biomass composition and properties for biofuel application was conducted based on reference peer-reviewed data plus own investigations. Initially, some general considerations and comparisons about composition and properties of biomass and coal as the most popular solid fuel are addressed. Then, some of the major advantages related to the composition and properties of biomass and/or biomass ash (BA) are discussed. They include: (1) high values of volatile matter, H, structural organic components, extractives and reactivity of biomass, water-soluble nutrient elements and alkaline-earth elements in biomass and BA, and pH of BA; and (2) low values of C, fixed C, ash, N, S, Si and initial ignition and combustion temperatures of biomass, and low contents of many trace elements including hazardous ones in biomass and BA. Further, some of the major disadvantages connected with the composition and properties of biomass and/or BA are described. They comprise: (1) high values of moisture and O in biomass, water-soluble fraction, alkaline and halogen elements, and some hazardous trace elements in biomass and BA; (2) low values of energy density (bulk density and calorific value), pH and ash-fusion temperatures of biomass, and bulk density and size of BA; (3) highly variable composition and properties of biomass and BA; and (4) indefinite availability of sustainable biomass resources for production of biofuels. Finally, a discussion about the availability of sustainable biomass resources for production of biofuels and biochemicals is given. It was found that the disadvantages of biomass for biofuel and biochemical applications prevail over the advantages; however, the major environmental, economic and social benefits appear to compensate the technological and other barriers caused by the unfavourable composition and properties of biomass.
•Composition and properties of algae and algae ash were summarized.•Comparative characterization between algae and other solid fuels was given.•Advantages of algae composition and properties were ...described.•Disadvantages and challenges of algae composition and properties were discussed.
Algae-based fuels are considered to be the most sustainable, renewable, effective and environment friendly response to climate change and food–feed security, as well as the only renewable energy resource that has the capacity to meet the global demand for fuels in the long-term. Therefore, an extended overview of the composition, properties and challenges of algae biomass for biofuel application was conducted based on reference peer-reviewed data plus own investigations. Initially, some general considerations such as current bioenergy situation and significance of biofuel generations, as well as different aspects related to biomass use as biofuels are discussed. Then, common issues concerning taxonomical classification, habitat environment, carbon reserve capacity, production, use, and main advantages and disadvantages of algae or algae biofuel are addressed. Further, more than 135 characteristics related to the chemical, phase and mineral composition and properties of algae and algae ash are evaluated and compared to those of terrestrial biomass, coal and their ashes. As a result specific benefits and obstacles connected with the composition and properties of algae and algae ash are discussed. The behaviour of organic and inorganic matter during algae combustion is also described. Finally, the major technological and environmental challenges related to algae-based fuels are emphasized. The present data demonstrate that the high contents of inorganic matter with unfavourable modes of element occurrences (chlorides, sulphates, carbonates, oxalates, nitrates and some oxyhydroxides, phosphates and amorphous material) in algae and algae ash provoke the most critical technological and environmental challenges during algae processing for biofuel application and especially during algae thermochemical conversion. Another very important challenge addressed is the indefinite availability of sustainable algae resources for production of biofuels and biochemicals and certain recommendations are given. It was found that the disadvantages of algae biofuel application prevail significantly over the advantages; however, the major economic, environmental and social benefits appear to compensate the technological and other barriers caused by the unfavourable composition and properties of algae.
•Five mixture design methods for SCC based on different principles are reviewed.•Feature and flow chart of mixture design procedure for each method is presented.•Advantages and disadvantages of each ...method is compared.•It provides valuable suggestions for choosing appropriate design method for SCC.
Mixture design is a very important step in production and application of concrete. Many mixture design methods have been proposed for self-compacting concrete (SCC). This paper presents a critical review on SCC mixture design methods in publications. Based on principles, those methods can be classified into five categories including empirical design method, compressive strength method, close aggregate packing method and methods based on statistical factorial model and rheology of paste model. The procedures, advantages and disadvantages of each method were discussed. The most appropriate method should be chosen according to actual situations to obtain high quality SCC with satisfactory properties.
Cancer is one of the leading causes of death worldwide, and the factors responsible for its progression need to be elucidated. Exosomes are structures with an average size of 100 nm that can ...transport proteins, lipids, and nucleic acids. This review focuses on the role of exosomes in cancer progression and therapy. We discuss how exosomes are able to modulate components of the tumor microenvironment and influence proliferation and migration rates of cancer cells. We also highlight that, depending on their cargo, exosomes can suppress or promote tumor cell progression and can enhance or reduce cancer cell response to radio- and chemo-therapies. In addition, we describe how exosomes can trigger chronic inflammation and lead to immune evasion and tumor progression by focusing on their ability to transfer non-coding RNAs between cells and modulate other molecular signaling pathways such as PTEN and PI3K/Akt in cancer. Subsequently, we discuss the use of exosomes as carriers of anti-tumor agents and genetic tools to control cancer progression. We then discuss the role of tumor-derived exosomes in carcinogenesis. Finally, we devote a section to the study of exosomes as diagnostic and prognostic tools in clinical courses that is important for the treatment of cancer patients. This review provides a comprehensive understanding of the role of exosomes in cancer therapy, focusing on their therapeutic value in cancer progression and remodeling of the tumor microenvironment. Graphical Keywords: Exosome, Cancer, Immunotherapy, Non-coding RNA, Biomarker, Prognosis
