Ali Khan^1,4, Somaiya Khan², Bilal Hassan³, Rizwan Khan^1,4, Zhonglong Zheng^1,4,*

CMC-Computers, Materials & Continua, Vol.77, No.1, pp. 403-424, 2023, DOI:10.32604/cmc.2023.040251

Abstract Smoking has an economic and environmental impact on society due to the toxic substances it emits. Convolutional Neural Networks (CNNs) need help describing low-level features and can miss important information. Moreover, accurate smoker detection is vital with minimum false alarms. To answer the issue, the researchers of this paper have turned to a self-attention mechanism inspired by the ViT, which has displayed state-of-the-art performance in the classification task. To effectively enforce the smoking prohibition in non-smoking locations, this work presents a Vision Transformer-inspired model called SmokerViT for detecting smokers. Moreover, this research utilizes a locally curated dataset of 1120 images… More >

A.C. Budiman^a,*, S. M. Hasheminejad^b, Sudirja^a, A. Mitayani^c, S. H. Winoto^d

Frontiers in Heat and Mass Transfer, Vol.19, pp. 1-6, 2022, DOI:10.5098/hmt.19.9

Abstract Streamwise development of counter-rotating vortices induced by three different types of chevron Vortex Generators (VGs) placed upstream an Electric Vehicles (EV) dummy battery module is experimentally visualized using a smoke-wire method. From the single chevron reference case, the mushroom-like vortices do not collapse until passing the module. When more chevrons are used in line, the vortices become more prominent. It can also be observed that the vortex sizes and shapes are significantly influenced by the spanwise base length of the chevron. The induced vortices from all three VGs suggest a potential heat transfer augmentation for the EV battery module application. More >

HM Iqbal Mahmud^a,b,*,† , Vijay Rajaram^b, Khalid Moinuddin^b

Frontiers in Heat and Mass Transfer, Vol.20, pp. 1-17, 2023, DOI:10.5098/hmt.20.2

Abstract This study has examined some important aspects of the engineered smoke control system, namely the shape of smoke reservoirs and the quantity and distribution of smoke extract points within a smoke compartment. Three different shapes of smoke reservoirs have been selected for analysis, namely square, rectangular, and T-shaped. The shape of the smoke reservoir has been varied, but the area, length and height have been kept identical. Four different configurations of extract points have been used in each shape of the reservoir: a single extract point located at the corner of the smoke reservoir, a single extract point located at… More >

Ayesha¹, Muhammad Javed Iqbal¹, Iftikhar Ahmad^2,*, Madini O. Alassafi², Ahmed S. Alfakeeh², Ahmed Alhomoud³

CMC-Computers, Materials & Continua, Vol.74, No.2, pp. 3647-3661, 2023, DOI:10.32604/cmc.2023.020916

Abstract Contemporarily numerous analysts labored in the field of Vehicle detection which improves Intelligent Transport System (ITS) and reduces road accidents. The major obstacles in automatic detection of tiny vehicles are due to occlusion, environmental conditions, illumination, view angles and variation in size of objects. This research centers on tiny and partially occluded vehicle detection and identification in challenging scene specifically in crowed area. In this paper we present comprehensive methodology of tiny vehicle detection using Deep Neural Networks (DNN) namely CenterNet. Substantially DNN disregards objects that are small in size 5 pixels and more false positives likely to happen in… More >

Yongming Chen^1,2,#, Shuai Huang^1,#, Han Zhao¹, Ru Yang², Yining He¹, Tianyu Zhao¹, Yunlong Zhang¹, Qinghong Kong^1,*, Shasha Sun^3,*, Junhao Zhang³

Journal of Renewable Materials, Vol.10, No.12, pp. 3119-3130, 2022, DOI:10.32604/jrm.2022.019576

Abstract To enhance the thermal stability and flame retardancy of epoxy resin (EP), beta-cyclodextrin (β-CD) is successfully introduced into the layered tin phenylphosphonate (SnPP), which is incorporated into EP matrix for preparing EP/β-CD@SnPP composites. The results indicate that the addition of β-CD@SnPP obviously improve the thermal stability and residual yield of EP composites at higher temperature. When the amount of β-CD@SnPP is only 4 wt%, EP/4β-CD@SnPP composites pass V-1 rating, and LOI value is up to 30.8%. Meanwhile, β- CD@SnPP effectively suppress the heat release and reduce the smoke production of EP/β-CD@SnPP composites in combustion, and the peak heat release rate… More >

Meixian Li¹, Xin Hu¹, Jie Yang¹, Hongyu Yang^1,3,*, Yao Yuan^2,*

Journal of Renewable Materials, Vol.10, No.10, pp. 2639-2654, 2022, DOI:10.32604/jrm.2022.019491

Abstract In this work, a bio-based flame retardant (Cy-HEDP) was synthesized from cytosine and HEDP through a facile salt-forming reaction and embedded into epoxy matrix to improve the flame retardancy and smoke suppression performance. The product Cy-HEDP was well characterized by FTIR, ¹ H and ³¹P NMR and SEM tests. On the basis of the results, by adding 15 wt% Cy-HEDP, the EP₁₅ can pass UL-94 V-0 rating, and the total smoke production (TSP) as well as total heat release (THR) can be decreased by 61.05% (from 22.61 to 8.7 m² /m² ) and 39.44% (from 103.19 to 62.50 MJ/m² )… More > Graphic Abstract

Pengfei Guan¹, Ping Li², Yiqiang Wu¹, Xingong Li¹, Guangming Yuan¹, Yingfeng Zuo^1,*

Journal of Renewable Materials, Vol.10, No.9, pp. 2451-2463, 2022, DOI:10.32604/jrm.2022.020459

Abstract To enhance mechanical properties and improve flame retardancy and smoke suppression of fast-growing poplar wood in wood applications, the wood was impregnated and modified. An organic phenolic prepolymer and inorganic sodium silicate was used as contrasting impregnation modifiers and wood samples were impregnated by a bionic “respiration” method with alternating positive and negative pressure. The weight percentage gain, density increase ratio, mechanical properties (bending and compressive strength and hardness), and water absorption rate of inorganic and organic-impregnated modified poplar wood (IIMPW and OIMPW, respectively) were compared and these properties in IIMPW were found to be higher than those of OIMPW… More >

Xianling Fu^#, Hongliang Ding^#, Xin Wang^*, Lei Song, Yuan Hu^*

Journal of Renewable Materials, Vol.10, No.9, pp. 2303-2317, 2022, DOI:10.32604/jrm.2022.020759

Abstract Although epoxy resin has been widely used in various fields, it still suffers from some problems including brittleness and flammability. In this study, a new phosphonic acid, N, N-bis(phosphomethyl) glycine (GDMP), was prepared by Mannich reaction with bio-based glycine and then a novel layered zirconium phosphonate (ZrGDMP) was synthesized using GDMP and zirconyl chloride hydrate as reactants. The chemical structure of ZrGDMP was well characterized by ¹H and ³¹P NMR, SEM, XRD and XPS. The effect of ZrGDMP on the flame retardancy, smoke suppression, strengthening and toughening performances of the epoxy matrix was investigated and evaluated. TGA results indicated that… More > Graphic Abstract

Bing Zhang¹, Sujie Yang¹, Mengru Liu¹, Panyue Wen², Xiuyu Liu¹, Gang Tang^1,*, Xiangrong Xu^3,4,*

Journal of Renewable Materials, Vol.10, No.5, pp. 1201-1220, 2022, DOI:10.32604/jrm.2022.018047

Abstract Biomass phytic acid has potential flame retardant value as the main form of phosphorus in plant seeds. In this study, phytate-based flame retardants aluminum phytate (PA-Al) and iron phytate (PA-Fe) were synthesized and characterized. Subsequently, they were introduced into rigid polyurethane foam (RPUF) as flame retardants by one-step water-blown method. The results indicated that RPUF/PA-Fe30 exhibited the highest char residue of 22.1 wt%, significantly higher than 12.4 wt% of RPUF. Cone calorimetry analysis showed that the total heat release (THR) of RPUF/PA-Al30 decreased by 17.0% and total smoke release (TSR) decreased by 22.0% compared with pure RPUF, which were the lowest, demonstrating… More > Graphic Abstract

Liying Zhu^*, Ang Wang, Fang Jin

FDMP-Fluid Dynamics & Materials Processing, Vol.17, No.6, pp. 1213-1222, 2021, DOI:10.32604/fdmp.2021.017572

Abstract In the present study, the laws of smoke diffusion during forest fires are determined using the general principles of fluid mechanics and dedicated data obtained experimentally using an “ad hoc” imaging technology. Experimental images mimicking smoke in a real scenario are used to extract some “statistics”. These in turn are used to obtain the “divergence” of the flow (this fluid-dynamic parameter describing the amount of air that converges to a certain place from the surroundings or vice versa). The results show that the divergence of the smoke depends on the outside airflow and finally tends to zero as time passes.… More >