Article
Energy & Fuels
Zhiwei Wang, Mengge Wu, Gaofeng Chen, Mengju Zhang, Tanglei Sun, Kiran G. Burra, Shuaihua Guo, Yan Chen, Shuhua Yang, Zaifeng Li, Tingzhou Lei, Ashwani K. Gupta
Summary: Co-pyrolysis technology is an important method for the efficient utilization of waste tires and biomass resources, with synergistic effects observed in the pyrolysis of waste tire and maize stalk. The co-pyrolysis process showed increased weight loss, and the FTIR and GC/MS analysis revealed similar functional groups and improved product yields.
Article
Agricultural Engineering
Haiqing Sui, Jingai Shao, Foster A. Agblevor, Yanhua Zhang, Xianhua Wang, Haiping Yang, Hanping Chen
Summary: This study investigates a multi-condenser system to separate pyrolytic vapors and produce bio-oils that are more resistant to aging. Bio-oil vapors from fast pyrolysis of cotton stalk were fractionated into four fractions using a fractional condensation system. The results demonstrate that the stability of the bio-oil was improved by effectively separating reactive aliphatic compounds, such as water rich organic acids, aldehydes, and ketones, from the other components. The study also found that the stability of bio-oil is influenced by active chemicals derived from fast pyrolysis and the aqueous acidic conditions because certain reactions require the presence of H+ as a catalyst. Additionally, the observation suggests that separating conventional bio-oils into different stages and concentrating the initial suspended solid particles (SS) in a certain fraction can suppress the presence of SS in bio-oils.
BIOMASS & BIOENERGY
(2023)
Article
Engineering, Environmental
Jingwei Qi, Kaihong Zhang, Ming Hu, Pengcheng Xu, Taoli Huhe, Xiang Ling, Haoran Yuan, Yijie Wang, Yong Chen
Summary: Tire pyrolysis is a complex thermochemical conversion process that transforms waste tires into valuable products. Data-driven machine learning models, such as Gaussian process regression (GPR) and random forest regression (RFR), optimized with Particle Swarm Optimization (PSO), demonstrate impressive prediction performance for pyrolysis product yields. These models provide a reliable and accurate method for predicting the yield of pyrolysis oil, char, and gas.
JOURNAL OF ENVIRONMENTAL CHEMICAL ENGINEERING
(2023)
Article
Chemistry, Analytical
P. V. Povalyaev, A. K. Asilbekov, A. Zh. Kaltaev, A. V. Vlasov, K. V. Slyusarsky, A. Ya. Pak, K. B. Larionov
Summary: This paper reports on the extraction and characterization of nanosized carbon material from the pyrolysis oil of waste tires. The study found that the released gas contained significant amounts of hydrogen, methane, and carbon monoxide. The obtained carbon material consisted of nanosized particles with a graphite-like structure and a wide range of specific surface areas. The analysis of samples derived from the pyrolysis oil and its high boiling point fraction revealed similarities to carbon black.
JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
(2023)
Article
Energy & Fuels
Ningbo Gao, Kamran Kamran, Zhengzhao Ma, Cui Quan
Summary: Co-pyrolysis of waste tire and offshore oil sludge can produce high oil yield, with an optimal blend ratio of 75% SWWT and 25% OOS. The resulting oil contains high oxygen, nitrogen, and heavy molecular hydrocarbons.
Article
Chemistry, Analytical
Mudassir Hussain Tahir, Naoto Shimizu
Summary: This study proposed a method of upgrading products by co-pyrolyzing hydrogen-deficient waste (such as cabbage waste) with hydrogen-rich waste (such as tire trash), achieving full resource utilization in an economical way. It was found that the addition of tire waste (TW) during the pyrolysis of cabbage waste (CW) had a coupling synergistic interaction. The activation energy was lowest for the sample with a mass ratio of 50%TW to CW. The relative concentrations of pyrolytic products changed significantly with temperature. As the mass ratio of TW increased, the yield of olefins and MAHs increased, while the yield of OCs and PAHs decreased.
JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
(2023)
Article
Chemistry, Analytical
Yingmei Zhai, Tianhua Yang, Yue Zhang, Yiming Zhu
Summary: Biomass torrefaction followed by co-pyrolysis with oil shale has great potential in upgrading bio-oil. A comparative analysis of oil shale co-pyrolysis with raw/torrefied corn stalk was conducted. Oil shale played a key role in promoting oil yield during co-pyrolysis, but only after corn stalk torrefaction. The optimal blending ratio of oil shale for both raw and torrefied corn stalk is 50%.
JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
(2023)
Article
Energy & Fuels
Oraleou Sangue Djandja, Zhicong Wang, Peigao Duan, Feng Wang, Yuping Xu
Summary: The study aimed to improve properties of waste tire pyrolysis oil by reducing nitrogen and sulfur contents using a combination of tetralin and hydrogen source. Various factors such as catalyst type, temperature, catalyst loading, time, and hydrogen pressure were examined to optimize the upgraded oil with Pt/C showing the highest performance. The upgraded oil had higher heating values and mainly consisted of aromatic compounds, with monocyclic aromatic hydrocarbons accounting for about 40% of the total content.
Article
Chemistry, Physical
Qianwang Cheng, Fanrui Meng, Xianchun Li, Chunyu Fan
Summary: The reaction parameters of K in-situ catalytic pyrolysis of cotton stalks at 600 degrees C were examined using the horizontal fixed bed pyrolysis method. The influence of K on the pyrolysis conversion mechanism of cotton stalks was investigated through various analyses. The addition of K2CO3 accelerated the breakdown of oxygen-containing rings, promoted the conversion of furan structure, and prevented the transformation of furan into long-chain alkanes.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2023)
Article
Chemistry, Applied
Mustafa Karagoz, Fikret Polat, Suat Saridemir, Murat Kadir Yesilyurt, Umit Agbulut
Summary: This study investigates the usability and impact of waste tire pyrolysis oil along with diesel and biogas dual fuel in CI engines. The results show that the presence of pyrolysis oil and biogas increases the unburnt emissions, but the introduction of biogas reduces NOx emissions. However, the use of pyrolysis oil worsens engine performance, resulting in increased BSFC and decreased BTE.
FUEL PROCESSING TECHNOLOGY
(2022)
Review
Chemistry, Applied
Guohao Zhang, Feng Chen, Yuhao Zhang, Liang Zhao, Jingye Chen, Liyuan Cao, Jinsen Gao, Chunming Xu
Summary: WTPO has great potential but is limited by high impurity content and poor fuel performance. Blending with diesel and cleaner production can enhance its fuel properties and reduce pollutant emissions. Increasing the value of WTPO for economic purposes is necessary.
FUEL PROCESSING TECHNOLOGY
(2021)
Review
Energy & Fuels
Felipe Campuzano, Juan Daniel Martinez, Andres F. Agudelo Santamaria, S. Mani Sarathy, William L. Roberts
Summary: Pyrolysis is seen as a crucial step in the transition from a linear to a circular economy and the defossilization of various economic sectors. Tire pyrolysis oil (TPO), derived from the pyrolysis of end-of-life tires, contains valuable chemicals that are building blocks of the petrochemical industry. This study reviews different pathways for producing value-added products from TPO and focuses on implementing conventional refinery practices such as distillation, fluid catalytic cracking (FCC), hydroprocessing, and steam cracking for TPO post-treatment.
Article
Chemistry, Applied
Yiliu Zhong, Jun Xu, Yuhan Pan, Zhitong Yin, Xinwen Wang, Yonggang Zhou, Qunxing Huang
Summary: The study found that aromatic-enriched tire pyrolysis oil (TPO) shows potential as a fuel with higher calorific value and lower combustion activation energy, suitable for use in industrial burners. Oils produced from synthetic rubber at 25 degrees Celsius exhibited a higher stable burning rate.
FUEL PROCESSING TECHNOLOGY
(2022)
Article
Agricultural Engineering
Panbo Yang, Shuheng Zhao, Quanguo Zhang, Jianjun Hu, Ronghou Liu, Zhen Huang, Yulong Gao
Summary: The study found that the synergistic effect between cotton stalk and high-ash coal in copyrolysis/gasification processes can be enhanced by heating to 950 degrees Celsius to increase gas production. There is a linear relationship between the gas yield during copyrolysis and the mixing ratio of cotton stalk, indicating almost no interaction between the two. The addition of steam can enhance the catalytic effect of alkali metals and alkaline earth metals in cotton stalk during cogasification, while the synergistic effect is reduced as the blending ratio of cotton stalk increases.
BIORESOURCE TECHNOLOGY
(2021)
Article
Agricultural Engineering
Qiuhao Wu, Letian Zhang, Linyao Ke, Qi Zhang, Xian Cui, Liangliang Fan, Anqi Dai, Chuangxin Xu, Qihang Zhang, Krik Bob, Rongge Zou, Yuhuan Liu, Roger Ruan, Yunpu Wang
Summary: This study found that the residue content of oil-bath co-torrefaction was the highest at 97.01%. Oil-bath co-torrefaction can maximize the retention of hydrogen atoms in corncob, which is beneficial for deoxygenation during pyrolysis. It can also reduce the average activation energy required for corncob decomposition.
BIORESOURCE TECHNOLOGY
(2023)
Article
Energy & Fuels
Shoaib Raza Khan, Muhammad Zeeshan, Muhammad Faheem Khokhar, Zeshan, Iftikhar Ahmad
Summary: This study investigates the co-pyrolysis of rice straw and waste tire, and shows that the feedstock ratio has a significant impact on the products.
BIOMASS CONVERSION AND BIOREFINERY
(2023)
Article
Green & Sustainable Science & Technology
Momina Ahmad, Muhammad Zeeshan
Summary: The objective of this study is to include environmental impact in optimization of concentrated solar power plants. Numerical investigations are conducted to compare the performance of solar towers and parabolic trough collectors at different climatic zones. Techno-economic analysis is used to quantify water usage and compare the environmental impact of concentrated solar power plants with natural gas-based power plants. Multi-objective 'balanced' solutions are proposed, which offer low levelized cost of electricity, high electricity generation, and significant reduction in environmental impact. Semi-arid climates are found suitable for concentrated solar power plant installation.
JOURNAL OF CLEANER PRODUCTION
(2023)
Review
Chemistry, Multidisciplinary
Najla Javed, Tayyaba Noor, Naseem Iqbal, Salman Raza Naqvi
Summary: Due to odd weather patterns and post-pandemic economic recovery, there has been an increase in global demand for oil, coal, and natural gas. However, the excessive usage of these fuels has led to depletion of their reserves and contributed to global warming and power shortage problems. In light of this, it is crucial to focus on and promote the use of renewable energy sources for power production and storage.
Article
Chemistry, Physical
Neelam Zaman, Naseem Iqbal, Tayyaba Noor
Summary: A simple approach using metal organic framework and nickel foam as an electrode for catalyzing methanol oxidation is reported. The NMC-MOF/NF catalysts showed the highest current density response and efficient catalytic oxidation of carbon monoxide. The NMC-MOF/NF electrode retained 100% of its catalytic activity after 20,000 seconds in methanol oxidation. This method enables the generation of energy-efficient products, such as hydrogen, from methanol.
Article
Materials Science, Multidisciplinary
Arif Ullah Khan, Tayyaba Noor, Naseem Iqbal, Neelam Zaman, Zakir Hussain
Summary: This study reports the successful adsorption of carbon dioxide gas using ZIF-8 and its g-C3N4 based composites at a temperature of 45°C and 0-15 bar pressure. The samples were characterized using different techniques, and the results show good structural and morphological properties. The ZIF-8@3wt% g-C3N4 composite exhibits the highest adsorption capacity of 315 mg/g.
JOURNAL OF MATERIALS SCIENCE
(2023)
Article
Multidisciplinary Sciences
Sana Zainab, Muhammad Azeem, Saif Ullah Awan, Syed Rizwan, Naseem Iqbal, Jamshaid Rashid
Summary: In this report, we developed different fabrication parameters to tailor the optical bandgap of graphene oxide (GO) nanosheets for electronic industry. We reduced the bandgap of GO nanosheets by optimizing the oxidation level and fabricating 2-dimensional nanocomposites containing GO/Iron-oxide. The reduction in bandgap and the interaction among the constituents of the nanocomposite make 5%-iron-oxide/95%-GO nanosheet sample a potential candidate for electronic devices.
SCIENTIFIC REPORTS
(2023)
Article
Chemistry, Multidisciplinary
Saleem Munir, Muhammad Amin, Naseem Iqbal, Amjad Iqbal, Ayman A. Ghfar
Summary: This study reveals that the presence of sulfur in ferric sulfate MOF can enhance the production of light hydrocarbons, while calcined ferric nitrate MOF shows the highest diesel production. The research also analyzes the XRD results, SEM images, FT-IR, and TGA testing of the prepared MOFs for downstream application of syngas to liquid fuels.
FRONTIERS IN CHEMISTRY
(2023)
Article
Energy & Fuels
Muhammad Waqas Nazar, Naseem Iqbal, Majid Ali, Hassan Nazir, M. Zain Bin Amjad
Summary: To improve the safety of Li-ion batteries, understanding their behavior under high temperature is crucial. In this study, charge and discharge experiments were conducted on battery packs to evaluate the impact of thermal management on battery performance. By analyzing the temperature distribution among the cells under different conditions and using phase change material, it was found that thermal management significantly affects the battery pack's performance and safety. Active cooling (air cooling) and passive cooling (using PCM) were both effective methods to reduce the temperature difference compared to ambient temperature, with passive cooling showing the most promising results.
JOURNAL OF ENERGY STORAGE
(2023)
Article
Energy & Fuels
Iqra Shaukat, Naseem Iqbal, Tayyaba Noor, Maryam Raza, Rabia Ahmad
Summary: In this study, CoSe/NC composites were synthesized by varying the amount of selenium powder while keeping the mass ratio of ZIF-67 constant. CoSe-1 showed excellent electrochemical performance with the highest specific capacitance and cyclic capability.
Article
Thermodynamics
Momina Ahmad, Muhammad Zeeshan, Junaid Aziz Khan
Summary: This study integrates meteorological and air quality parameters, lifecycle costs and environmental emissions with geospatial, techno-economic parameters to determine potential and suitability of photovoltaic power plants. Strategic planning is required to bridge the gap between sustainability theory and good practice.
ENERGY CONVERSION AND MANAGEMENT
(2023)
Article
Chemistry, Multidisciplinary
Rimsha Mehek, Naseem Iqbal, Tayyaba Noor, Yuanshen Wang, Alexey Y. Ganin
Summary: This study successfully prepared a composite material by carbonization of V-MIL-101, in which vanadium oxide nanoparticles and nanoporous carbon network were embedded, significantly improving the electrochemical performance of the material as a cathode in an aqueous Zn-ion battery system. The loading of manganese oxide further stabilized the composite material and improved the rate capability of the cathode material in the aqueous zinc ion battery. The MnO2@NVC composite cathode material exhibited a capacity of 299 mAh/g at a 0.1C rate for 100 cycles, benefiting from the synergistic effect of the high conductivity of vanadium oxide nanoparticles and the suitable voltage of MnO2. The materials showed superior capacity retention and better cycling performance compared to unmodified vanadium oxide nanoparticles on a carbon substrate as cathode material. Comparative morphological and electrochemical studies confirmed the improved performance, suggesting that the vanadium oxide nanoparticles anchored on a high surface area carbon network intertwined with manganese oxide nanowires provide enhanced conductivity.
JOURNAL OF INDUSTRIAL AND ENGINEERING CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Fozia Bibi, Rafaqat Hussain, Naseem Iqbal, Shaukat Saeed, Muhammad Waseem, Eslam B. Elkaeed, Murefah Mana Al-Anazy, Sirajul Haq
Summary: This study synthesized magnetic activated carbon (MAC) as an efficient adsorbent material using the hydrothermal method. The adsorption behavior of As(III) onto MAC was examined, and it was found that MCNa had a removal efficiency of 99%. The pseudo 2nd-order kinetics and Langmuir model were applicable to the adsorption process.
ARABIAN JOURNAL OF CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Sadia Khan, Tayyaba Noor, Naseem Iqbal, Erum Pervaiz, Lubna Yaqoob
Summary: The synthesis and characterization of ZIF-67, g-C3N4, and their composite for electrochemical water-splitting application were investigated. The combination of ZIF-67 with g-C3N4 improved the electrochemical kinetics. The 3 wt% g-C3N4@ZIF-67 composite exhibited superior catalytic activity for water splitting with low overpotential values and stable performance. It is suggested to be a promising candidate for electrochemical water-splitting application.
Article
Engineering, Environmental
Haroon Hayat, Tayyaba Noor, Naseem Iqbal, Rabia Ahmed, Neelam Zaman, Yan Huang
Summary: For metal air batteries, the synthesis of efficient non-precious metal-based electrocatalysts is crucial. In this study, Cu MOF and its g-C3N4 based composites were prepared and characterized. The Cu MOF and g-C3N4-based electrode synergistically enhanced the electrochemical process, improving electron transport and charge transfer efficiency. The composite Cu MOF (5 wt%) showed high stability and improved performance in oxygen reduction reaction (ORR) analysis.
JOURNAL OF ENVIRONMENTAL CHEMICAL ENGINEERING
(2023)
Article
Chemistry, Physical
Asif Khan, Naseem Iqbal, Tayyaba Noor, Neelam Zaman, Shoaib Raza Khan
Summary: This study focuses on the utilization of waste low-density polyethylene (LDPE) plastic by pyrolysis, using fuel oil fly ash catalyst to convert it into valuable fuels. The findings suggest that this waste can be commercially converted into oil, addressing environmental and energy crises.
SUSTAINABLE ENERGY & FUELS
(2023)
Article
Green & Sustainable Science & Technology
Cameron Bracken, Nathalie Voisin, Casey D. Burleyson, Allison M. Campbell, Z. Jason Hou, Daniel Broman
Summary: This study presents a methodology and dataset for examining compound wind and solar energy droughts, as well as the first standardized benchmark of energy droughts across the Continental United States (CONUS) for a 2020 infrastructure. The results show that compound wind and solar droughts have distinct spatial and temporal patterns across the CONUS, and the characteristics of energy droughts are regional. The study also finds that compound high load events occur more often during compound wind and solar droughts than expected.
Article
Green & Sustainable Science & Technology
Ning Zhang, Yanghao Yu, Jiawei Wu, Ershun Du, Shuming Zhang, Jinyu Xiao
Summary: This paper provides insights into the optimal configuration of CSP plants with different penetrations of wind power by proposing an unconstrained optimization model. The results suggest that large solar multiples and TES are preferred in order to maximize profit, especially when combined with high penetrations of wind and photovoltaic plants. Additionally, the study demonstrates the economy and feasibility of installing electric heaters (EH) in CSP plants, which show a linear correlation with the penetration of variable energy resources.
Article
Green & Sustainable Science & Technology
M. Szubel, K. Papis-Fraczek, S. Podlasek
Article
Green & Sustainable Science & Technology
J. Silva, J. C. Goncalves, C. Rocha, J. Vilaca, L. M. Madeira
Summary: This study investigated the methanation of CO2 in biogas and compared two different methanation reactors. The results showed that the cooled reactor without CO2 separation achieved a CO2 conversion rate of 91.8%, while the adiabatic reactors achieved conversion rates of 59.6% and 67.2%, resulting in an overall conversion rate of 93.0%. Economic analysis revealed negative net present worth values, indicating the need for government monetary incentives.
Article
Green & Sustainable Science & Technology
Yang Liu, Yonglan Xi, Xiaomei Ye, Yingpeng Zhang, Chengcheng Wang, Zhaoyan Jia, Chunhui Cao, Ting Han, Jing Du, Xiangping Kong, Zhongbing Chen
Summary: This study investigated the effect of using nanofiber membrane composites containing Prussian blue-like compound nanoparticles (PNPs) to relieve ammonia nitrogen inhibition of rural organic household waste during high-solid anaerobic digestion and increase methane production. The results showed that adding NMCs with 15% PNPs can lower the concentrations of volatile fatty acids and ammonia nitrogen, and increase methane yield.
Article
Green & Sustainable Science & Technology
Zhong Ge, Xiaodong Wang, Jian Li, Jian Xu, Jianbin Xie, Zhiyong Xie, Ruiqu Ma
Summary: This study evaluates the thermodynamic, exergy, and economic performance of a double-stage organic flash cycle (DOFC) using ten eco-friendly hydrofluoroolefins. The influences of key parameters on performance are analyzed, and the advantages of DOFC over single-stage type are quantified.
Article
Green & Sustainable Science & Technology
Nicolas Kirchner-Bossi, Fernando Porte-Agel
Summary: This study investigates the optimization of power density in wind farms and its sensitivity to the available area size. A novel genetic algorithm (PDGA) is introduced to optimize power density and turbine layout. The results show that the PDGA-driven solutions significantly reduce the levelized cost of energy (LCOE) compared to the default layout, and exhibit a convex relationship between area and LCOE or power density.
Article
Green & Sustainable Science & Technology
Chunxiao Zhang, Dongdong Li, Lin Wang, Qingpo Yang, Yutao Guo, Wei Zhang, Chao Shen, Jihong Pu
Summary: In this study, a novel reversible liquid-filled energy-saving window that effectively regulates indoor solar radiation heat gain is proposed. Experimental results show that this window can effectively reduce indoor temperature during both summer and winter seasons, while having minimal impact on indoor illuminance.
Article
Green & Sustainable Science & Technology
Alessandro L. Aguiar, Martinho Marta-Almeida, Mauro Cirano, Janini Pereira, Leticia Cotrim da Cunha
Summary: This study analyzed the Brazilian Equatorial Shelf using a high-resolution ocean model and found significant tidal variations in the area. Several hypothetical barrages were proposed with higher annual power generation than existing barrages. The study also evaluated the installation effort of these barrages.
Article
Green & Sustainable Science & Technology
Francesco Superchi, Nathan Giovannini, Antonis Moustakis, George Pechlivanoglou, Alessandro Bianchini
Summary: This study focuses on the optimization of a hybrid power station on the Tilos island in Greece, aiming to increase energy export and revenue by optimizing energy fluxes. Different scenarios are proposed to examine the impact of different agreements with the grid operator on the optimal solution.
Article
Green & Sustainable Science & Technology
Peimaneh Shirazi, Amirmohammad Behzadi, Pouria Ahmadi, Sasan Sadrizadeh
Summary: This research presents two novel energy production/storage/usage systems to reduce energy consumption and environmental effects in buildings. A biomass-fired model and a solar-driven system integrated with photovoltaic thermal (PVT) panels and a heat pump were designed and assessed. The results indicate that the solar-based system has an acceptable energy cost and the PVT-based system with a heat pump is environmentally superior. The biomass-fired system shows excellent efficiency.
Article
Green & Sustainable Science & Technology
Zihao Qi, Yingling Cai, Yunxiang Cui
Summary: This study aims to investigate the operational characteristics of the solar-ground source heat pump system (SGSHPS) in Shanghai under different operation modes. It concludes that tandem operation mode 1 is the optimal mode for winter operation in terms of energy efficiency.
Article
Green & Sustainable Science & Technology
L. Bartolucci, S. Cordiner, A. Di Carlo, A. Gallifuoco, P. Mele, V. Mulone
Summary: Spent coffee grounds are a valuable biogenic waste that can be used as a source of biofuels and valuable chemicals through pyrolysis and solvent extraction processes. The study found that heavy organic bio-oil derived from coffee grounds can be used as a carbon-rich biofuel, while solvent extraction can extract xantines and p-benzoquinone, which are important chemicals for various industries. The results highlight the promising potential of solvent extraction in improving the economic viability of coffee grounds pyrolysis-based biorefineries.
Article
Green & Sustainable Science & Technology
Luiza de Queiroz Correa, Diego Bagnis, Pedro Rabelo Melo Franco, Esly Ferreira da Costa Junior, Andrea Oliveira Souza da Costa
Summary: Building-integrated photovoltaics, especially organic solar technology, are important for reducing greenhouse gas emissions in the building sector. This study analyzed the performance of organic panels laminated in glass in a vertical installation in Latin America. Results showed that glass lamination and vertical orientation preserved the panels' performance and led to higher energy generation in winter.
Article
Green & Sustainable Science & Technology
Zhipei Hu, Shuo Jiang, Zhigao Sun, Jun Li
Summary: This study proposes innovative fin arrangements to enhance the thermal performance of latent heat storage units. Through optimization of fin distribution and prediction of transient melting behaviors, it is found that fin structures significantly influence heat transfer characteristics and melting behaviors.
