Other affiliations: University of Science and Technology of China, University of Maryland, College Park
Bio: Lin Jiang is an academic researcher from Nanjing University of Science and Technology. The author has contributed to research in topics: Flame spread & Combustion. The author has an hindex of 22, co-authored 67 publications receiving 1224 citations. Previous affiliations of Lin Jiang include University of Science and Technology of China & University of Maryland, College Park.
TL;DR: COVID-19 will ensure that masks are always considered as an essential commodity in future pandemic preparedness and utilise raw materials that are side-stream products of local industries to develop facemasks having equal or better efficiency than the conventional ones.
Abstract: The onset of coronavirus pandemic has sparked a shortage of facemasks in almost all nations. Without this personal protective equipment, healthcare providers, essential workers, and the general public are exposed to the risk of infection. In light of the aforementioned, it is critical to balance the supply and demand for masks. COVID-19 will also ensure that masks are always considered as an essential commodity in future pandemic preparedness. Moreover, billions of facemasks are produced from petrochemicals derived raw materials, which are non-degradable upon disposal after their single use, thus causing environmental pollution and damage. The sustainable way forward is to utilise raw materials that are side-stream products of local industries to develop facemasks having equal or better efficiency than the conventional ones. In this regard, wheat gluten biopolymer, which is a by-product or co-product of cereal industries, can be electrospun into nanofibre membranes and subsequently carbonised at over 700 °C to form a network structure, which can simultaneously act as the filter media and reinforcement for gluten-based masks. In parallel, the same gluten material can be processed into cohesive thin films using plasticiser and hot press. Additionally, lanosol, a naturally-occurring substance, imparts fire (V-0 rating in vertical burn test), and microbe resistance in gluten plastics. Thus, thin films of flexible gluten with very low amounts of lanosol (<10 wt%) can be bonded together with the carbonised mat and shaped by thermoforming to create the facemasks. The carbon mat acting as the filter can be attached to the masks through adapters that can also be made from injection moulded gluten. The creation of these masks could simultaneously be effective in reducing the transmittance of infectious diseases and pave the way for environmentally benign sustainable products.
TL;DR: In this article, two typical building-used polymer wastes, extruded polystyrene (XPS) and rigid polyurethane (RPU), were selected to conduct a series of thermogravimetry (TG) experiments.
Abstract: The utilization of polymer wastes for volatile fuel production has been considered as a sustainable and environmental-friendly approach for achieving better waste management, pollution protection, and renewable energy security. Polymer pyrolysis, as an ideal method for polymer waste converted into storable fuel, was explored thoroughly in this study from pyrolysis kinetics to evolved gas analysis. Two typical building-used polymer wastes, extruded polystyrene (XPS) and rigid polyurethane (RPU), were selected to conduct a series of thermogravimetry (TG) experiments. Then commonly-used isoconversional methods were employed to calculate the kinetic parameters of the pyrolysis during the whole conversion. Kinetic models of XPS and RPU thermal degradations were identified from nineteen reaction models by Coats-Redfern and masterplots methods. Then accommodation function was employed to adjust the theoretical model for reconstruction. Considering the complexities of RPU component and degradation process, Py-GC/MS was used to identify the volatile product component at 250, 340, and 460 °C, respectively. Results showed that there are large parts of volatile alcohols and ethers escaped during RPU pyrolysis process. The results of this study have implications concerning kinetic triplet determination method and escaped gas analysis during polymer waste pyrolysis process.
TL;DR: In this article, a new heat balance equation is established to study the heat and mass transfer during smoke propagation process, where the thermal radiation, air entrainment and heat convection are considered.
Abstract: In order to study the hazard of the hot smoke which is toxic and in high temperature, a new heat balance equation is established to study the heat and mass transfer during smoke propagation process. The heat balance equation can be converted into an inhomogeneous linear differential equation of first order in the end, where the thermal radiation, air entrainment and heat convection are considered. The solution to this differential equation is proposed and the parameters are discussed. Furthermore, the factors that influence the smoke temperature distribution are discussed according to the equation we established. Additionally, in order to examine the solution of smoke temperature distribution in longitudinal direction, a set of small scale experiments are carried out where the variables are the ventilation velocity and heat release rate. Otherwise, a comparison with other tests' data both from small scale and real tunnels is conducted. Results show that the smoke temperature distribution correlates in good agreement with the solution we assumed both in our experiments and other tests, confirming that the theoretical analysis and the application of this formula in determining the smoke temperature distribution in tunnel fires in longitudinal direction and assessing the hazard the hot smoke. The investigation presented here considers only the cases when the ratio of the length to the width of the tunnel is large so that the smoke movement can be considered as One-dimensional Horizontal Spread.
TL;DR: The aim of this work was motivated by the research of sample width and thickness effects on upward flame spread behavior, including flame spread rate during acceleration propagation for different sample thickness and width, theoretical global mass loss prediction based on Emmons's hypothesis, and dimensionless flame height scaling with dimensionless heat release rate for steady stage burning.
Abstract: Upward flame spread has the same propagating direction with air flow and buoyancy, and features as the most hazardous fire case in all flame spread configurations. It has been a long time for fire researchers to find a simple and effective method to evaluate upward flame spread behaviors, especially for different materials and sample sizes. The aim of this work was motivated by the research of sample width and thickness effects on upward flame spread behavior, including flame spread rate during acceleration propagation for different sample thickness and width, theoretical global mass loss prediction based on Emmons's hypothesis, and dimensionless flame height scaling with dimensionless heat release rate for steady stage burning. Four kinds of sample thicknesses were selected, including 1.7, 3.5, 5, and 7mm. For each kind of thickness, six sample widths ranging from 40 to 90mm were prepared. To eliminate the side flame spreading effects, one set of contrast experiments with sample sides sealed was also performed, by which way flame could only spread along sample front surface and flame propagation was inhibited along both sides. Based on Emmons's hypothesis, a method for calculation of global mass loss rate was developed. Theoretical global mass loss rate over pyrolysis surface of upward flame spread configurations was calculated and could fit the experimental data well. Finally, a dimensionless heat-release rate for wall flames of different sample sizes was used to scale the dimensionless flame height with a power-law exponent 0.58. The results of this study have implications concerning designs for high-rise building fire safety problems and can help to get better understandings of upward flame spread mechanism from aspects of heat and mass transfer.
27 Mar 2021
TL;DR: In this article, a review of the state-of-the-art technologies for the adoption of the circular economy concept in biocomposite development is presented, highlighting the opportunities and challenges pertaining to the implementation of CE have been discussed in detail.
Abstract: Biocomposites being environmentally-friendly alternative to synthetic composites are gaining increasing demand for various applications. Hence, biocomposite development should be integrated within a circular economy (CE) model to ensure a sustainable production that is simultaneously innocuous towards the environment. This review presents an overview of the state-of-the-art technologies for the adoption of the CE concept in biocomposite development. The study outlined the properties, environmental and economic impacts of biocomposites. A critical review of the life-cycle assessment of biocomposite for evaluating greenhouse gas emissions and carbon footprints was conducted. In addition, the opportunities and challenges pertaining to the implementation of CE have been discussed in detail. Recycling and utilisation of bio-based constituents were identified as the critical factors in embracing CE. Therefore, the development of innovative recycling technologies and an enhanced use of novel biocomposite constituents could lead to a reduction in material waste and environmental footprints. This article is one of the first studies to review the circularity of biocomposites in detail that will stimulate further research in enhancing the sustainability of these polymeric materials.
TL;DR: In this paper, the authors provide a comprehensive review of the thermal runaway phenomenon and related fire dynamics in singe and multi-cell battery packs, as well as potential fire prevention measures.
Abstract: Lithium ion batteries (LIBs) are booming due to their high energy density, low maintenance, low self-discharge, quick charging and longevity advantages. However, the thermal stability of LIBs is relatively poor and their failure may cause fire and, under certain circumstances, explosion. The fire risk hinders the large scale application of LIBs in electric vehicles and energy storage systems. This manuscript provides a comprehensive review of the thermal runaway phenomenon and related fire dynamics in singe LIB cells as well as in multi-cell battery packs. Potential fire prevention measures are also discussed. Mitigating the hazards associated with a growing number of LIB applications represents a significant new challenge for the fire safety engineering community. Some perspectives and outlooks on the future of LIB fire safety research and safety engineering are given.
Max Planck Society1, Autonomous University of Madrid2, University of Turin3, Curtin University4, University of Nottingham5, University of Oslo6, Ben-Gurion University of the Negev7, Aarhus University8, University of the Western Cape9, ENEA10, National Scientific and Technical Research Council11, Griffith University12, École Polytechnique Fédérale de Lausanne13, Swiss Federal Laboratories for Materials Science and Technology14
TL;DR: In this article, the present status and the future perspectives of the use of metal hydrides for hydrogen storage are discussed, as well as a new hydrogen compression technology is proposed.
Abstract: Metal hydrides are known as a potential efficient, low-risk option for high-density hydrogen storage since the late 1970s. In this paper, the present status and the future perspectives of the use of metal hydrides for hydrogen storage are discussed. Since the early 1990s, interstitial metal hydrides are known as base materials for Ni – metal hydride rechargeable batteries. For hydrogen storage, metal hydride systems have been developed in the 2010s  for use in emergency or backup power units, i. e. for stationary applications. With the development and completion of the first submarines of the U212 A series by HDW (now Thyssen Krupp Marine Systems) in 2003 and its export class U214 in 2004, the use of metal hydrides for hydrogen storage in mobile applications has been established, with new application fields coming into focus. In the last decades, a huge number of new intermetallic and partially covalent hydrogen absorbing compounds has been identified and partly more, partly less extensively characterized. In addition, based on the thermodynamic properties of metal hydrides, this class of materials gives the opportunity to develop a new hydrogen compression technology. They allow the direct conversion from thermal energy into the compression of hydrogen gas without the need of any moving parts. Such compressors have been developed and are nowadays commercially available for pressures up to 200 bar. Metal hydride based compressors for higher pressures are under development. Moreover, storage systems consisting of the combination of metal hydrides and high-pressure vessels have been proposed as a realistic solution for on-board hydrogen storage on fuel cell vehicles. In the frame of the “Hydrogen Storage Systems for Mobile and Stationary Applications” Group in the International Energy Agency (IEA) Hydrogen Task 32 “Hydrogen-based energy storage”, different compounds have been and will be scaled-up in the near future and tested in the range of 500 g to several hundred kg for use in hydrogen storage applications.
01 May 2010
TL;DR: It was found that the constructed RBF exhibited a high performance than MLP, ANFIS and MR for predicting S%.
Abstract: Research highlights? The use of multiple regression (MR), artificial neural network (ANN) and artificial neuro-fuzzy inference system (ANFIS) models, for the prediction of swell percent of soils, was described and compared. ? However the accuracies of ANN and ANFIS models may be evaluated relatively similar, it is shown that the constructed ANN models of RBF and MLP exhibit a high performance than ANFIS and multiple regression for predicting swell percent of clays. ? The performance comparison showed that the soft computing system is a good tool for minimizing the uncertainties in the soil engineering projects. ? The use of soft computing will also may provide new approaches and methodologies, and minimize the potential inconsistency of correlations. In the recent years, new techniques such as; artificial neural networks and fuzzy inference systems were employed for developing of the predictive models to estimate the needed parameters. Soft computing techniques are now being used as alternate statistical tool. Determination of swell potential of soil is difficult, expensive, time consuming and involves destructive tests. In this paper, use of MLP and RBF functions of ANN (artificial neural networks), ANFIS (adaptive neuro-fuzzy inference system) for prediction of S% (swell percent) of soil was described, and compared with the traditional statistical model of MR (multiple regression). However the accuracies of ANN and ANFIS models may be evaluated relatively similar. It was found that the constructed RBF exhibited a high performance than MLP, ANFIS and MR for predicting S%. The performance comparison showed that the soft computing system is a good tool for minimizing the uncertainties in the soil engineering projects. The use of soft computing will also may provide new approaches and methodologies, and minimize the potential inconsistency of correlations.
TL;DR: The fundamental aspects of the production of PUFs are reviewed, the new challenges that the PUFs industry are expected to confront regarding process methodologies in the near future are outlined, and some alternatives are also presented.
Abstract: Polymeric foams can be found virtually everywhere due to their advantageous properties compared with counterparts materials. Possibly the most important class of polymeric foams are polyurethane foams (PUFs), as their low density and thermal conductivity combined with their interesting mechanical properties make them excellent thermal and sound insulators, as well as structural and comfort materials. Despite the broad range of applications, the production of PUFs is still highly petroleum-dependent, so this industry must adapt to ever more strict regulations and rigorous consumers. In that sense, the well-established raw materials and process technologies can face a turning point in the near future, due to the need of using renewable raw materials and new process technologies, such as three-dimensional (3D) printing. In this work, the fundamental aspects of the production of PUFs are reviewed, the new challenges that the PUFs industry are expected to confront regarding process methodologies in the near future are outlined, and some alternatives are also presented. Then, the strategies for the improvement of PUFs sustainability, including recycling, and the enhancement of their properties are discussed.
TL;DR: This volume is much more than an update of previous volumes of the ‘Handbook’ and should have given more prominence to Cook, who, in the early 1970s, was the first to demonstrate improvement in neurological deficit with SCS.
Abstract: This is a very good book and a very important one. The list of authors (107) reads like the ‘Who’s Who’ of spinal cord medicine. The volume is much more than an update of previous volumes of the ‘Handbook’, which also dealt with this topic and were published in 1976 and 1992. New developments have produced important and exciting changes that have altered the subject almost beyond recognition. This statement is true as regards the clinical achievments including diagnosis, prognosis and rehabilitation, but not quite so accurate as regards pre-clinical research. The 38 chapters form five sections. The first section, on development and anatomical perspectives, deals with the growth and maturation of the spinal cord. A good overview of the embryology, both cellular and molecular, is followed by a description of maldevelopment and the implications of molecular and genetic defects. The anatomy and biomechanisms are dealt with in terms of fundamental principles applied to the spinal column and spinal cord, and lead on to spinal cord injury. This is a good base for the following chapters that form the second section and which deal with the diagnosis, prognosis and monitoring of spinal cord trauma. Hopefully, in the future, there will be clinical trials of therapeutic interventions (but more of that later), and this will require accurate and quantitative measurement. The standard and recognized method is the ASIA scale, but this has limitations, and the best potential lies with neurophysiology and with advanced high-resolution neuroimaging techniques.This is dealt with in two excellent and comprehensive chapters. The majority of spinal cord injury outcome measures are understandably related to the younger population. However, the increasingly ageing population in most countries has to be addressed. This is a problem in the entire field of medicine. Specifically, in spinal cord injury, the average age of injury has increased and is still increasing. A short but notable chapter deals with the pathophysiology of the ageing nervous system, the aetiology and clinical presentation, complications and mortality and outcome. The third section deals with acute spinal cord injury: medical and surgical treatment, management and rehabilitation. These are useful straightforward reviews but are also good accounts of exciting developments. It is pointed out, and it cannot be over-emphasized, that spinal cord injury, although interrupting motor and sensory long tracts, still leaves neuronal networks intact below the site of the lesion. This is potentially a much more fruitful area of study than the conventional, and so far fruitless, pursuit of axonal repair. Chapter 20, on the changing field of rehabilitation, gives a brief account of how neural activity has a role in central nervous system (CNS) development and plasticity, but this important subject could have been improved to a great extent. A chapter on spinal cord stimulation (SCS) should have given more prominence to Cook, who, in the early 1970s, was the first to demonstrate improvement in neurological deficit with SCS. He was carrying out this procedure for pain on a young sufferer with multiple sclerosis when to his great surprise he saw a marked improvement in spasticity with consequent improvement in ambulation. The speed of change suggested that this was almost certainly due to an increase in inhibition. Cook took his observations to the neurologists in his hospital and later to the neurological societies in New York. They refused to even investigate this. Subsequent studies (elsewhere) demonstrated recordable and reproducible neurophysiologcal changes at spinal and brain-stem levels and eventually led to the formation of the International Neuromodulation Society. What Cook had observed was no more than that reported by Frohlich and Sherrington in 1902: after decerebration in cat, dog and Macaque, stimulation of the lower thoracic and lumbar region of the spinal cord showed ‘..an effect...constant and regular...evoked marked inhibition of the rigidity..’. Cook deserves much greater recognition. Section 4 is concerned with chronic-stage rehabilitation, and overlaps with the previous section. In fact, it is difficult to see why the two sections were separated. ‘Rehabilitation strategies that optimize spontaneous repair and promote neurological recovery are becoming mainstream’. Is this perhaps rather optimistic? ‘Spontaneous repair’ and ‘neurological recovery’ risks undue raising of hopes. This is based on a single case report about 11 years ago. Nevertheless, this is an interesting section that, in this chapter, deals with the effect of activity including electrical stimulation on synapses. Although the field is not exactly comprehensively covered, a good trenchant point is made: that conventional rehabilitation of spinal cord disease ignores the beneficial effects of afferent feedback and stimulation, which is aninteresting and potentially exciting concept that brings into focus the undamaged, but altered, central nervous system. The final section, section 5, deals with preclinical research ‘bridging the gap between bench and bedside.’ This is the longest section in 15 chapters and approximately one-third of the total volume.The first chapter in this section sets out the goals for therapy, discusses protocols and gives an algorithm for discovery through to clinical use. The authors point out that no clinical trial so far has been shown to be effective (reviewer’s emphasis). An outstanding and thoughtful chapter follows, again emphasizing the improvement in animals and man with appropriate afferent input, and discusses the challenges to be met. However, there is some inconsistency among the contributors, which, though understandable, is somewhat confusing. Chapter 25 states that ‘basic research in spinal cord repair is promising’. A more realistic description might state the opposite. Further chapters point out that there are no satisfactory solutions. Indeed, chapter 33 begins with ‘so far, there is no clinical procedure for inducing severed nerve fibres to regenerate’. Further on, the authors state that ‘the grandfather of the transplantation strategies was espoused by Santiago Ramon y Cajal in the 19th century’. Spinal Cord (2013) 51, 797–799 & 2013 International Spinal Cord Society All rights reserved 1362-4393/13