scholarly journals Improving the Flame Retardance of Polyisocyanurate Foams by Dibenzo[d,f][1,3,2]dioxaphosphepine 6-Oxide-Containing Additives

Polymers ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1242 ◽  
Author(s):  
Lenz ◽  
Pospiech ◽  
Paven ◽  
Albach ◽  
Günther ◽  
...  
Keyword(s):  
Thermal Decomposition ◽  
Oxidation State ◽  
Chemical Structure ◽  
Flame Retardants ◽  
State Of The Art ◽  
Fire Behavior ◽  
Flame Retardance ◽  
Fire Properties

A series of new flame retardants (FR) based on dibenzo[d,f][1,3,2]dioxaphosphepine 6-oxide (BPPO) incorporating acrylates and benzoquinone were developed previously. In this study, we examine the fire behavior of the new flame retardants in polyisocyanurate (PIR) foams. The foam characteristics, thermal decomposition, and fire behavior are investigated. The fire properties of the foams containing BPPO-based derivatives were found to depend on the chemical structure of the substituents. We also compare our results to state-of-the-art non-halogenated FR such as triphenylphosphate and chemically similar phosphinate, i.e. 9,10-dihydro-9-oxa-10- phosphaphenanthrene-10-oxide (DOPO), based derivatives to discuss the role of the phosphorus oxidation state.

scholarly journals Influence of Ammonium Polyphosphate/Lignin Ratio on Thermal and Fire Behavior of Biobased Thermoplastic: The Case of Polyamide 11

Materials ◽  
2019 ◽  
Vol 12 (7) ◽  
pp. 1146 ◽  
Author(s):  
Aurélie Cayla ◽  
François Rault ◽  
Stéphane Giraud ◽  
Fabien Salaün ◽  
Rodolphe Sonnier ◽  
...  
Keyword(s):  
Flame Retardancy ◽  
Flame Retardants ◽  
Fire Behavior ◽  
Melting Process ◽  
Development Trend ◽  
Ammonium Polyphosphate ◽  
Polyamide 11 ◽  
Biobased Materials ◽  
Combustion Flow ◽  
Fire Properties

Flame retardancy of polymers is a recurring obligation for many applications. The development trend of biobased materials is no exception to this rule, and solutions of flame retardants from agro-resources give an advantage. Lignin is produced as a waste by-product from some industries, and can be used in the intumescent formation development as a source of carbon combined with an acid source. In this study, the flame retardancy of polyamide 11 (PA) is carried out by extrusion with a kraft lignin (KL) and ammonium polyphosphate (AP). The study of the optimal ratio between the KL and the AP makes it possible to optimize the fire properties as well as to reduce the cost and facilitates the implementation of the blend by a melting process. The properties of thermal decomposition and the fire reaction have been studied by thermogravimetric analyzes, pyrolysis combustion flow calorimetry (PCFC) and vertical flame spread tests (UL94). KL permits a charring effect delaying thermal degradation and decreases by 66% the peak of heat release rate in comparison with raw PA. The fire reaction of the ternary blends is improved even if KL-AP association does not have a synergy effect. The 25/75 and 33/67 KL/AP ratios in PA give an intumescence behavior under flame exposure.

scholarly journals Fire Behavior of Wood-Based Composite Materials

Polymers ◽  
2021 ◽  
Vol 13 (24) ◽  
pp. 4352
Author(s):  
Juliana Sally Renner ◽  
Rhoda Afriyie Mensah ◽  
Lin Jiang ◽  
Qiang Xu ◽  
Oisik Das ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Composite Materials ◽  
Flame Retardancy ◽  
Flame Retardants ◽  
Wood Fiber ◽  
Fire Behavior ◽  
Manufacturing Techniques ◽  
Materials Used ◽  
Fire Properties ◽  
Wood Based Composite

Wood-based composites such as wood plastic composites (WPC) are emerging as a sustainable and excellent performance materials consisting of wood reinforced with polymer matrix with a variety of applications in construction industries. In this context, wood-based composite materials used in construction industries have witnessed a vigorous growth, leading to a great production activity. However, the main setbacks are their high flammability during fires. To address this issue, flame retardants are utilized to improve the performance of fire properties as well as the flame retardancy of WPC material. In this review, flame retardants employed during manufacturing process with their mechanical properties designed to achieve an enhanced flame retardancy were examined. The addition of flame retardants and manufacturing techniques applied were found to be an optimum condition to improve fire resistance and mechanical properties. The review focuses on the manufacturing techniques, applications, mechanical properties and flammability studies of wood fiber/flour polymer/plastics composites materials. Various flame retardant of WPCs and summary of future prospects were also highlighted.

Potential Uses of Vinegar as a Medicine and Related in vivo Mechanisms

2016 ◽  
Vol 86 (3-4) ◽  
pp. 127-151 ◽  
Author(s):  
Zeshan Ali ◽  
Zhenbin Wang ◽  
Rai Muhammad Amir ◽  
Shoaib Younas ◽  
Asif Wali ◽  
...  
Keyword(s):  
Chemical Structure ◽  
Review Paper ◽  
Heart Diseases ◽  
Folk Medicine ◽  
Active Role ◽  
Current Review ◽  
Different Types ◽  
Positive Effect

While the use of vinegar to fi ght against infections and other crucial conditions dates back to Hippocrates, recent research has found that vinegar consumption has a positive effect on biomarkers for diabetes, cancer, and heart diseases. Different types of vinegar have been used in the world during different time periods. Vinegar is produced by a fermentation process. Foods with a high content of carbohydrates are a good source of vinegar. Review of the results of different studies performed on vinegar components reveals that the daily use of these components has a healthy impact on the physiological and chemical structure of the human body. During the era of Hippocrates, people used vinegar as a medicine to treat wounds, which means that vinegar is one of the ancient foods used as folk medicine. The purpose of the current review paper is to provide a detailed summary of the outcome of previous studies emphasizing the role of vinegar in treatment of different diseases both in acute and chronic conditions, its in vivo mechanism and the active role of different bacteria.

Coinage and the Tributary Mode of Production

2018 ◽  
Author(s):  
Eduardo Manzano Moreno
Keyword(s):  
Roman Empire ◽  
Middle Ages ◽  
Social Role ◽  
State Of The Art ◽  
Early Middle Ages ◽  
The Social ◽  
Simple Question ◽  
Mode Of Production

This chapter addresses a very simple question: is it possible to frame coinage in the Early Middle Ages? The answer will be certainly yes, but will also acknowledge that we lack considerable amounts of relevant data potentially available through state-of-the-art methodologies. One problem is, though, that many times we do not really know the relevant questions we can pose on coins; another is that we still have not figured out the social role of coinage in the aftermath of the Roman Empire. This chapter shows a number of things that could only be known thanks to the analysis of coins. And as its title suggests it will also include some reflections on greed and generosity.

scholarly journals Water-Worked Gravel Bed: State-of-the-Art Review

Water ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 694 ◽  
Author(s):  
Ellora Padhi ◽  
Subhasish Dey ◽  
Venkappayya R. Desai ◽  
Nadia Penna ◽  
Roberto Gaudio
Keyword(s):  
State Of The Art ◽  
Flow Characteristics ◽  
Streamwise Velocity ◽  
Secondary Currents ◽  
Gravel Bed ◽  
Natural Stream ◽  
Art Research ◽  
The Comparative Study ◽  
Water Work

In a natural gravel-bed stream, the bed that has an organized roughness structure created by the streamflow is called the water-worked gravel bed (WGB). Such a bed is entirely different from that created in a laboratory by depositing and spreading gravels in the experimental flume, called the screeded gravel bed (SGB). In this paper, a review on the state-of-the-art research on WGBs is presented, highlighting the role of water-work in determining the bed topographical structures and the turbulence characteristics in the flow. In doing so, various methods used to analyze the bed topographical structures are described. Besides, the effects of the water-work on the turbulent flow characteristics, such as streamwise velocity, Reynolds and form-induced stresses, conditional turbulent events and secondary currents in WGBs are discussed. Further, the results form WGBs and SGBs are compared critically. The comparative study infers that a WGB exhibits a higher roughness than an SGB. Consequently, the former has a higher magnitude of turbulence parameters than the latter. Finally, as a future scope of research, laboratory experiments should be conducted in WGBs rather than in SGBs to have an appropriate representation of the flow field close to a natural stream.

scholarly journals From Exosome Glycobiology to Exosome Glycotechnology, the Role of Natural Occurring Polysaccharides

2021 ◽  
Vol 2 (2) ◽  
pp. 311-338
Author(s):  
Giulia Della Rosa ◽  
Clarissa Ruggeri ◽  
Alessandra Aloisi
Keyword(s):  
State Of The Art ◽  
Cell Communication ◽  
Pathological Conditions ◽  
New Findings ◽  
Cell Type Specific ◽  
New Perspective ◽  
And Function ◽  
And Personalized Medicine ◽  
Innate Ability

Exosomes (EXOs) are nano-sized informative shuttles acting as endogenous mediators of cell-to-cell communication. Their innate ability to target specific cells and deliver functional cargo is recently claimed as a promising theranostic strategy. The glycan profile, actively involved in the EXO biogenesis, release, sorting and function, is highly cell type-specific and frequently altered in pathological conditions. Therefore, the modulation of EXO glyco-composition has recently been considered an attractive tool in the design of novel therapeutics. In addition to the available approaches involving conventional glyco-engineering, soft technology is becoming more and more attractive for better exploiting EXO glycan tasks and optimizing EXO delivery platforms. This review, first, explores the main functions of EXO glycans and associates the potential implications of the reported new findings across the nanomedicine applications. The state-of-the-art of the last decade concerning the role of natural polysaccharides—as targeting molecules and in 3D soft structure manufacture matrices—is then analysed and highlighted, as an advancing EXO biofunction toolkit. The promising results, integrating the biopolymers area to the EXO-based bio-nanofabrication and bio-nanotechnology field, lay the foundation for further investigation and offer a new perspective in drug delivery and personalized medicine progress.

scholarly journals Role of long non‐coding RNAs in adipogenesis: State of the art and implications in obesity and obesity‐associated diseases

2021 ◽  
Author(s):  
Federica Rey ◽  
Valentina Urrata ◽  
Luisa Gilardini ◽  
Simona Bertoli ◽  
Valeria Calcaterra ◽  
...  
Keyword(s):  
State Of The Art ◽  
Associated Diseases ◽  
Non Coding Rnas

scholarly journals Multifunctional Role of Chitosan Edible Coatings on Antioxidant Systems in Fruit Crops: A Review

2021 ◽  
Vol 22 (5) ◽  
pp. 2633
Author(s):  
Giuseppina Adiletta ◽  
Marisa Di Matteo ◽  
Milena Petriccione
Keyword(s):  
State Of The Art ◽  
Antioxidant Systems ◽  
Edible Coatings ◽  
Ros Production ◽  
Oxygen Species ◽  
Fruit Crops ◽  
Oxidative Damages ◽  
Film Forming ◽  
Anti Oxidant

Chitosan-based edible coatings represent an eco-friendly and biologically safe preservative tool to reduce qualitative decay of fresh and ready-to-eat fruits during post-harvest life due to their lack of toxicity, biodegradability, film-forming properties, and antimicrobial actions. Chitosan-based coatings modulate or control oxidative stress maintaining in different manner the appropriate balance of reactive oxygen species (ROS) in fruit cells, by the interplay of pathways and enzymes involved in ROS production and the scavenging mechanisms which essentially constitute the basic ROS cycle. This review is carried out with the aim to provide comprehensive and updated over-view of the state of the art related to the effects of chitosan-based edible coatings on anti-oxidant systems, enzymatic and non-enzymatic, evaluating the induced oxidative damages during storage in whole and ready-to-eat fruits. All these aspects are broadly reviewed in this review, with particular emphasis on the literature published during the last five years.

scholarly journals The Role of Surgery in Lung Cancer Treatment: Present Indications and Future Perspectives—State of the Art

Cancers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 3711
Author(s):  
François Montagne ◽  
Florian Guisier ◽  
Nicolas Venissac ◽  
Jean-Marc Baste
Keyword(s):  
Lung Cancer ◽  
Residual Disease ◽  
State Of The Art ◽  
Locally Advanced ◽  
Small Cell Lung ◽  
Lung Cancers ◽  
Screening Programs ◽  
Systemic Therapies

Non-small cell lung cancers (NSCLC) are different today, due to the increased use of screening programs and of innovative systemic therapies, leading to the diagnosis of earlier and pre-invasive tumors, and of more advanced and controlled metastatic tumors. Surgery for NSCLC remains the cornerstone treatment when it can be performed. The role of surgery and surgeons has also evolved because surgeons not only perform the initial curative lung cancer resection but they also accompany and follow-up patients from pre-operative rehabilitation, to treatment for recurrences. Surgery is personalized, according to cancer characteristics, including cancer extensions, from pre-invasive and local tumors to locally advanced, metastatic disease, or residual disease after medical treatment, anticipating recurrences, and patients’ characteristics. Surgical management is constantly evolving to offer the best oncologic resection adapted to each NSCLC stage. Today, NSCLC can be considered as a chronic disease and surgery is a valuable tool for the diagnosis and treatment of recurrences, and in palliative conditions to relieve dyspnea and improve patients’ comfort.

scholarly journals Peptidogalactomannan from Histoplasma capsulatum yeast cell wall: role of the chemical structure in recognition and activation by peritoneal macrophages

2021 ◽  
Author(s):  
Giulia Maria Pires dos Santos ◽  
Gustavo Ramalho Cardoso dos Santos ◽  
Mariana Ingrid Dutra da Silva Xisto ◽  
Rodrigo Rollin-Pinheiro ◽  
Andréa Regina de Souza Baptista ◽  
...  
Keyword(s):  
Cell Wall ◽  
Yeast Cell ◽  
Chemical Structure ◽  
Histoplasma Capsulatum ◽  
Peritoneal Macrophages ◽  
Yeast Cell Wall
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