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2021

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Articles 31 - 60 of 9963

Full-Text Articles in Engineering

Flexible Microfluidic Device With Nonplanar Interdigitated Microelectrodes, Saud Alssaidy Dec 2021

Flexible Microfluidic Device With Nonplanar Interdigitated Microelectrodes, Saud Alssaidy

Theses

The lab-on-a-chip concept has improved significantly in recent years to meet global demand for various applications with the advent of new technologies. Much progress has been achieved, but many microfluidic devices still suffer from design limitations in terms of sensitivity and selectivity because they use rigid, fragile substrate materials and conventional electrodes, which do not provide high sensitivity or selectivity and suffer from signal-to-noise ratio issues. This work proposes a novel device architecture that uses flexible, transparent top and bottom layers integrated with (nonplanar interdigitated microelectrodes) to create a sandwich-like flexible substrate base. The top and bottom layers consist of …


Itraconazole Nanocomposites Prepared Via Rotary Evaporator Drying Of Nanomilled Suspensions, Alexander Santos Coelho Dec 2021

Itraconazole Nanocomposites Prepared Via Rotary Evaporator Drying Of Nanomilled Suspensions, Alexander Santos Coelho

Theses

The aim of this study is to explore the feasibility of rotary evaporation for drying wetmilled drug suspensions as a novel approach to produce drug nanocomposites that exhibit fast redispersion and immediate drug release. To this end, the physical stability of the nanomilled itraconazole (drug) suspensions, a.k.a., nanosuspensions, during the milling and storage; the drying of the itraconazole nanosuspensions via the rotary evaporator; and the type/loading of various polymers/surfactants (dispersants) on aqueous redispersion and drug release from the nanocomposites were examined. Our results suggest that smaller drug particle size, owing to nanomilling, and smaller nanocomposite particle size, owing to optimized …


Energy Planning Model Design For Forecasting The Final Energy Consumption Using Artificial Neural Networks, Haidy Eissa Dec 2021

Energy Planning Model Design For Forecasting The Final Energy Consumption Using Artificial Neural Networks, Haidy Eissa

Theses and Dissertations

“Energy Trilemma” has recently received an increasing concern among policy makers. The trilemma conceptual framework is based on three main dimensions: environmental sustainability, energy equity, and energy security. Energy security reflects a nation’s capability to meet current and future energy demand. Rational energy planning is thus a fundamental aspect to articulate energy policies. The energy system is huge and complex, accordingly in order to guarantee the availability of energy supply, it is necessary to implement strategies on the consumption side. Energy modeling is a tool that helps policy makers and researchers understand the fluctuations in the energy system. Over the …


Sustainable Wastewater Treatment Technology For Rural Communities, Yousra Ahmed Dec 2021

Sustainable Wastewater Treatment Technology For Rural Communities, Yousra Ahmed

Theses and Dissertations

Egypt is considered the country with the largest population in the Middle East Region. It is also expected to have the most significant population increase. The main objective of the present research was to develop a sustainable and effective wastewater treatment technology based on locally available materials such as sand and fabric in the treatment process. From the results obtained from the different experimental runs, it can be concluded that the use of fabric-aided sand filters achieves significant removal efficiency, especially in terms of COD and TSS. The results indicated the technical feasibility of utilizing different fabric materials with nylon …


Smart Building Energy Model Using Artificial Intelligence, Riad El Abed, Mohamed El-Gohary Dec 2021

Smart Building Energy Model Using Artificial Intelligence, Riad El Abed, Mohamed El-Gohary

BAU Journal - Science and Technology

This paper presents a Smart Building Energy Model of Residential Building using Artificial Neural Network model (ANN) to assist architects and engineers in selecting the optimum alternative design of building envelope parameters such that external wall and roof insulation material types and window types that minimizes the cost of energy consumption of a residential building to transform it to a green building.

Up to 1540 Simulations using different material thickness and conductivity values of material insulation properties and windows types are carried out in eQuest software for simulation.. The simulations results are implemented to create an artificial neural network inverse …


Role Of Technological Revolution In Transport And Communications Development, Mohamad B. Chami Dec 2021

Role Of Technological Revolution In Transport And Communications Development, Mohamad B. Chami

BAU Journal - Science and Technology

The arousal of technology has changed a lot of aspects in human life and has drastically changed its path through a revolution that changed the whole world. This revolution took place in various aspects while affecting significantly the global economy and from those fields that considerably affect the life of human beings in the previous and current centuries are Information and Communication Technology (ICT) and transportation. It is these two factors that play a major role in the economy of countries and dominate the lives of societies in the world. Thus, this paper studies the impact of the technology revolution …


Overview On The Lebanese Environmental Governance System: Main Hazards In The Oil And Gaz Sector, Rami Harkous Dec 2021

Overview On The Lebanese Environmental Governance System: Main Hazards In The Oil And Gaz Sector, Rami Harkous

BAU Journal - Science and Technology

Due to harsh environment and vulnerability of marine ecosystems, many challenges are faced regarding offshore oil and gas activities. Many steps are currently undertaken to overcome such challenges.

As Lebanon is inside the new oil and gas sector in its offshore region, plans should be made to address environmental challenges that may occur in this sector. The Lebanese environmental governance system meets international standards in various aspects but some gaps are addressed to manage such risks that may be encountered with oil and gas activities in the Lebanese offshore. This article ends by a fast run through environmental regulatory authority, …


Investigation Of The Experimental And Numerical Flexural Behavior Of Innovative Totally Encased Composite Beams, Nour Wehbi, Adnan Masri, Oussama Baalbaki Dec 2021

Investigation Of The Experimental And Numerical Flexural Behavior Of Innovative Totally Encased Composite Beams, Nour Wehbi, Adnan Masri, Oussama Baalbaki

BAU Journal - Science and Technology

Composite steel-concrete beams have been widely used in long span construction and high rise buildings due to their favorable behavior in terms of high strength, stiffness, and ductility. In this research, the flexural behavior of an innovative steel-concrete composite section is investigated experimentally and verified numerically using ABAQUS software. The studied section is composed of steel tubular specimen or steel hollow pipe totally encased in concrete in the absence of any flexural or shear reinforcement. Instead, steel mesh wraps are used around the tubular steel specimen to provide sufficient steel-concrete bond. All of the studied beams have the same 3m …


New Type Of Lightweight Aggregate For Use In Structural Concrete, Jamal Khatib, Ali Jahami, Oussama Baalbaki, Adel Elkordi Dec 2021

New Type Of Lightweight Aggregate For Use In Structural Concrete, Jamal Khatib, Ali Jahami, Oussama Baalbaki, Adel Elkordi

BAU Journal - Science and Technology

This research studied the utilization of municipal solid waste incineration bottom ash (MSWI-BA) in lightweight coarse aggregate (LWC) production. A special method was followed to prepare the new aggregate to fully replace the normal aggregates (NWA) in concrete. The mechanical properties such as compressive strength, tensile strength, and elasticity modulus were investigated for the LWC concrete. Then, two beams were prepared; one from LWC and the other from NWC. The structural performance of beams made up of lightweight aggregates compared to normal aggregates was investigated. The results showed that this type of aggregates led to a 20% reduction in concrete …


Evaluating Technology-Mediated Collaborative Workflows For Telehealth, Christopher Bondy Ph.D., Pengcheng Shi, Pamela Grover Md, Vicki Hanson, Linlin Chen, Rui Li Dec 2021

Evaluating Technology-Mediated Collaborative Workflows For Telehealth, Christopher Bondy Ph.D., Pengcheng Shi, Pamela Grover Md, Vicki Hanson, Linlin Chen, Rui Li

Articles

Goals: This paper discusses the need for a predictable method to evaluate gains and gaps of collaborative technology-mediated workflows and introduces an evaluation framework to address this need. Methods: The Collaborative Space Analysis Framework (CS-AF), introduced in this research, is a cross-disciplinary evaluation method designed to evaluate technology-mediated collaborative workflows. The 5-step CS-AF approach includes: (1) current-state workflow definition, (2) current-state (baseline) workflow assessment, (3) technology-mediated workflow development and deployment, (4) technology-mediated workflow assessment, (5) analysis, and conclusions. For this research, a comprehensive, empirical study of hypertension exam workflow for telehealth was conducted using the CS-AF approach. Results: The CS-AF …


Stress Classification Using Deep Learning With 1d Convolutional Neural Networks, Abdulrazak Yahya Saleh, Lau Khai Xian Dec 2021

Stress Classification Using Deep Learning With 1d Convolutional Neural Networks, Abdulrazak Yahya Saleh, Lau Khai Xian

Knowledge Engineering and Data Science

Stress has been a major problem impacting people in various ways, and it gets serious every day. Identifying whether someone is suffering from stress is crucial before it becomes a severe illness. Artificial Intelligence (AI) interprets external data, learns from such data, and uses the learning to achieve specific goals and tasks. Deep Learning (DL) has created an impact in the field of Artificial Intelligence as it can perform tasks with high accuracy. Therefore, the primary purpose of this paper is to evaluate the performance of 1D Convolutional Neural Networks (1D CNNs) for stress classification. A Psychophysiological stress (PS) dataset …


Research On High-Rap Mixtures With Rejuvenator - Field Implementation, Nitish R. Bastola, Mahdieh Khedmati, Hamzeh Haghshenas Dec 2021

Research On High-Rap Mixtures With Rejuvenator - Field Implementation, Nitish R. Bastola, Mahdieh Khedmati, Hamzeh Haghshenas

Nebraska Department of Transportation: Research Reports

The use of Rejuvenating Agents (RAs), as Recycled Asphalt Pavement (RAP) modifiers, has been increasing over the past years. However, the field performance of asphalt mixtures containing high-RAP materials and modified with RAs has raised some concerns regarding the long-term performance of RAs. This study evaluated the laboratory and field performance of high-RAP mixtures with and without bio-oil RA. Three sets of plant-produced specimens were collected: 1) laboratory-compacted; 2) field-compacted and cored after paving; and 3) field-compacted and cored after one and two years. The Hamburg Wheel Tracking (HWT) test was used to evaluate the specimens' resistance to rutting and …


Removal Of Methylene Blue By Adsorption Of Water Hyacinth Derived Active Carbon Embedded With Cobalt Nanoparticles, Hany A. Elazab, A. O. Okasha, M. A. Radwan, M. A. Sadek, Amin Firouzi, Tamer T. El-Idreesy Dec 2021

Removal Of Methylene Blue By Adsorption Of Water Hyacinth Derived Active Carbon Embedded With Cobalt Nanoparticles, Hany A. Elazab, A. O. Okasha, M. A. Radwan, M. A. Sadek, Amin Firouzi, Tamer T. El-Idreesy

Chemical and Biochemical Engineering Faculty Research & Creative Works

In this research, active carbon-based catalyst synthesis and characterization were tested for potential catalysts to be used in dye removal of methylene blue (MB). Water hyacinth is one of the major problems that is facing humankind and especially here in Egypt. One of the implications of industrial activities is environmental pollution. Dyes used in the production of textiles, paper, and clothes are one of the major pollutants. The waste of those dyes discharged into water supplies without treatment or with ineffective treatment harmfully impacts the environment. In this research, the treatment is implemented using active carbon-based catalysts using embedded nanoparticles. …


Scale Model Equations And Optimization For Annular Flow Of Non-Newtonian Fluids Between Eccentric And Rotating Cylinders, Wei Zhang, Pooya Khodaparast, Amin Mehrabian Dr., Amir Shojaei Dec 2021

Scale Model Equations And Optimization For Annular Flow Of Non-Newtonian Fluids Between Eccentric And Rotating Cylinders, Wei Zhang, Pooya Khodaparast, Amin Mehrabian Dr., Amir Shojaei

Progress in Scale Modeling, an International Journal

A broad range of engineering applications involves helical flow of non-Newtonian fluids between two eccentric cylinders. These applications often require estimation of the frictional pressure losses along the axes of the cylinders. Laboratory flow loops are commonly used to study the flow characteristics at smaller scales of investigation. This study uses the laws of similarity and dimensional analysis to obtain a set of scaling equations between the laboratory and prototype scales of the described annular flow. These equations are derived for four types of fluid rheology including Newtonian, power-law, Bingham-plastic, and yield power-law.

Results are expressed through a set of …


Numerical Investigation On The Effect Of Spectral Radiative Heat Transfer Within An Ablative Material, Raghava S. C. Davuluri, Rui Fu, Kaveh A. Tagavi, Alexandre Martin Dec 2021

Numerical Investigation On The Effect Of Spectral Radiative Heat Transfer Within An Ablative Material, Raghava S. C. Davuluri, Rui Fu, Kaveh A. Tagavi, Alexandre Martin

Mechanical Engineering Faculty Publications

The spectral radiative heat flux could impact the material response. In order to evaluate it, a coupling scheme between KATS - MR and P1 approximation model of radiation transfer equation (RTE) is constructed and used. A Band model is developed that divides the spectral domain into small bands of unequal widths. Two verification studies are conducted: one by comparing the simulation computed by the Band model with pure conduction results and the other by comparing with similar models of RTE. The comparative results from the verification studies indicate that the Band model is computationally efficient and can be used to …


A Comparison Of Solid Electrolyte Interphase Formation And Evolution On Highly Oriented Pyrolytic And Disordered Graphite Negative Electrodes In Lithium-Ion Batteries, Haoyu Zhu, Joshua A. Russell, Zongtang Fang, Pete Barnes, Lan Li, Corey M. Efaw, Allison Muenzer, Jeremy May, Kailash Hamal, I. Francis Cheng, Paul H. Davis, Eric J. Dufek, Hui Xiong Dec 2021

A Comparison Of Solid Electrolyte Interphase Formation And Evolution On Highly Oriented Pyrolytic And Disordered Graphite Negative Electrodes In Lithium-Ion Batteries, Haoyu Zhu, Joshua A. Russell, Zongtang Fang, Pete Barnes, Lan Li, Corey M. Efaw, Allison Muenzer, Jeremy May, Kailash Hamal, I. Francis Cheng, Paul H. Davis, Eric J. Dufek, Hui Xiong

Materials Science and Engineering Faculty Publications and Presentations

The presence and stability of solid electrolyte interphase (SEI) on graphitic electrodes is vital to the performance of lithium-ion batteries (LIBs). However, the formation and evolution of SEI remain the least understood area in LIBs due to its dynamic nature, complexity in chemical composition, heterogeneity in morphology, as well as lack of reliable in situ/operando techniques for accurate characterization. In addition, chemical composition and morphology of SEI are not only affected by the choice of electrolyte, but also by the nature of the electrode surface. While introduction of defects into graphitic electrodes has promoted their electrochemical properties, how such structural …


Trajectory Optimization For Connected And Autonomous Vehicle Platooning And Split Operations: Modeling And Experiments, Qianwen Li Dec 2021

Trajectory Optimization For Connected And Autonomous Vehicle Platooning And Split Operations: Modeling And Experiments, Qianwen Li

USF Tampa Graduate Theses and Dissertations

Emerging connected and autonomous vehicle (CAV) platoon technology holds great potential in improving mobility, enhancing riding comfort, reducing fuel consumption, and mitigating congestion. It reduces car-following gaps via cyber connections. Further, it smooths vehicle trajectories via automated control. Smoothed trajectories and improved aerodynamic efficiency from reduced car-following gaps improve fuel and space efficiency, thus improving traffic performance.

Motivated by such promising advantages, this dissertation investigates trajectory optimization for two basic CAV platoon operations, i.e., platooning and split, which are the premise to implement this technology to benefit society. Two two-stage optimization problems are formulated to solve the platooning and split …


Research Of Physical And Mechanical Properties Of Babbits Filled In Sliding Bearings, K G. Gaparov Dec 2021

Research Of Physical And Mechanical Properties Of Babbits Filled In Sliding Bearings, K G. Gaparov

Scientific-technical journal

The article presents the results of research of physical and mechanical properties of babbites prepared from scrap and wastes poured into sliding bearings. The development of the technology of recycling scrap and babbites waste is aimed at optimizing the parameters of the technology of cleaning and melting babbites for reuse of so-called secondary babbites.


Method And Methods For Determining Shapes And Sizes Of Solar Dryer Elements, Sh M. Mirzaev, J R. Kodirov, S S. Ibragimov Dec 2021

Method And Methods For Determining Shapes And Sizes Of Solar Dryer Elements, Sh M. Mirzaev, J R. Kodirov, S S. Ibragimov

Scientific-technical journal

This article presents the calculation of the drying plant, the shape of which is a parallelepiped with non-isosceles triangular bases. Concepts were selected, on the basis of which a computational computational method was developed and the geometric dimensions of the elements of a direct type dryer were determined. The formula for the ratio of the dimensions of the height to the length and, accordingly, to the width of the dryer has been established, and a method has been developed for determining the dimensions of the dampers intended for the flow of air from the environment into the chamber and for …


Estimation Of The Service Life Of Span Structures In Predicting The Durability Of Reinforced Concrete Bridges, Sh.B. Akhmedov, Kh. Almenov, Sh.Sh. Shojalilov, Sh.Sh. Safarov Dec 2021

Estimation Of The Service Life Of Span Structures In Predicting The Durability Of Reinforced Concrete Bridges, Sh.B. Akhmedov, Kh. Almenov, Sh.Sh. Shojalilov, Sh.Sh. Safarov

The Scientific Journal of Vehicles and Roads

In recent years, on the roads of Uzbekistan and other countries, there has been a dangerous increase in various damages in the operated superstructures, caused by an increase in the service life and traffic intensity of vehicles and cargo tension.


Indicators Of Determining The Productivity Of Motor Graders Under Natural Conditions, N.R. Aslonov, S.S. Yusubjonov, S.M. Mirkholiqov Dec 2021

Indicators Of Determining The Productivity Of Motor Graders Under Natural Conditions, N.R. Aslonov, S.S. Yusubjonov, S.M. Mirkholiqov

The Scientific Journal of Vehicles and Roads

In the article, Motor Graders are self-propelled machines that level and shape the ground, and their equipment consists of a fully rotating blade overturner, located between the rear and front bridges of the pneumatic wheel drive.


Evaluation Of Reliability Indicators Of A Transformer Angular Displacement Transducer, S.F. Amirov, M.S. Yakubov, N.R. Yuldashev Dec 2021

Evaluation Of Reliability Indicators Of A Transformer Angular Displacement Transducer, S.F. Amirov, M.S. Yakubov, N.R. Yuldashev

The Scientific Journal of Vehicles and Roads

Based on the analysis of statistical data on the state of transformer angular displacement transducers, the following calculations of probabilistic reliability indicators were performed: failure rate, mean time to failure; the probability of failure-free operation with a sufficiently long operation and gamma-percentage resource; confidence upper and lower bounds are determined, under the chosen conditions of significance, the calculated values ​​satisfy Pearson's χ^2 criterion and therefore do not contradict the experimental data. By analyzing the selected levels of significance, the existence of exponential and normal laws in the laws of probability distribution was revealed.


Warranty And Post-Warranty Service For Vehicles, U.A. Nurullayev, D.M. Zukhurova Dec 2021

Warranty And Post-Warranty Service For Vehicles, U.A. Nurullayev, D.M. Zukhurova

The Scientific Journal of Vehicles and Roads

This article examines the characteristics of warranty and post-warranty service, the specifics of the work to identify problems and take into account the prospects of warranty and post-warranty service development, and compares warranty and post-warranty service before and after equipment purchase.


Processing Of The Results Of Comparisons Of Verification Installations Of The Same Level Of Accuracy, A. Abdukayumov Dec 2021

Processing Of The Results Of Comparisons Of Verification Installations Of The Same Level Of Accuracy, A. Abdukayumov

The Scientific Journal of Vehicles and Roads

Methods of processing the results of comparisons of verification installations of the same level of accuracy on the example of frequency and time standards are considered. A comparative analysis of the methods used to compare the verification installations is performed. The conditions for confirming the metrological status (metrological characteristics) of the verification installations are noted. The method of comparison of verification installations of the same level of accuracy is proposed. The results of the study of the pairwise comparison of frequency and time standards, the difference of the arithmetic mean readings, estimates of the total variance, the arithmetic mean readings …


Method Of Determination Of Characteristics Of Crushed Rocks, B.Yе. Kosymbetov Dec 2021

Method Of Determination Of Characteristics Of Crushed Rocks, B.Yе. Kosymbetov

The Scientific Journal of Vehicles and Roads

The article describes the properties of heat resistance and frost resistance of a cone crusher when crushing rocks, and it is established that the transported stones have an abrasive effect on the cone crusher during crushing. Efficiency, of the crushing chamber, the composition of stones in the deposit, the percentage of their correct use of crushing power during construction work. The abrasive wear of the working bodies of the conical crushers was revealed.


Evaluation Of The Efficiency Of Vehicles And Refrigeration Equipment Transporting Perishable Goods, Q.U. Urinbayev Dec 2021

Evaluation Of The Efficiency Of Vehicles And Refrigeration Equipment Transporting Perishable Goods, Q.U. Urinbayev

The Scientific Journal of Vehicles and Roads

Today, the volume of exports and imports is growing, and the demand for food is growing as the world's population grows. Further improvement of the rules of transportation of goods by road, as well as improving the safety of transportation of perishable products is a very important issue. One of the vehicles designed to transport perishable goods in road transport is a refrigerator. Selecting the thickness of the panels for the refrigerator compartment of the refrigerator One of the main applications in rigid polyurethane foam is the use of turgon wall wall sandwich panels as a layer of thermal insulation …


Methods For Assessing The Efficiency Of Urban Public Transport, A.A. Nazarov Dec 2021

Methods For Assessing The Efficiency Of Urban Public Transport, A.A. Nazarov

The Scientific Journal of Vehicles and Roads

The article presents methods for assessing the effectiveness of urban public transport based on the analysis of the operational characteristics of their types. Methods for a comprehensive assessment of options for solving the urban public transport system are analyzed.


Development Of Radiochemical Quality Control Methods For Ra-223 And Th-227 Radiotherapies, Abigail Hasson Dec 2021

Development Of Radiochemical Quality Control Methods For Ra-223 And Th-227 Radiotherapies, Abigail Hasson

McKelvey School of Engineering Graduate Student Theses & Dissertations

Introduction. Radiolabeled molecules for use in disease detection and targeted treatment are a mainstay of patient management. The majority of radiopharmaceuticals deployed to date undergo a single radioactive transition (decay) to reach a stable ground state. Complex emitters, which produce a series of daughter radionuclides, are emerging as novel radiopharmaceuticals, and there is a need for the proper validation of content and purity using common quality control instrumentation. Hypothesis. There is a need for proper characterization of complex emitters for more accurate quality control on readily available equipment. Here, we demonstrate the novel characterization of Th-227 and Ra-223 using a …


Influence Of Heat Treatment Time On Cathode Material Cr8O21 For Lithium Battery, Jiu-Kang Teng, Qing-Jie Wang, Liang Zhang, Hong-Mei Zhang, Xiao-Tao Chen, Peng Zhang, Jin-Bao Zhao Dec 2021

Influence Of Heat Treatment Time On Cathode Material Cr8O21 For Lithium Battery, Jiu-Kang Teng, Qing-Jie Wang, Liang Zhang, Hong-Mei Zhang, Xiao-Tao Chen, Peng Zhang, Jin-Bao Zhao

Journal of Electrochemistry

Chromium oxide (Cr8O21) cathode material for lithium batteries was synthesized by thermal decomposition of chromium trioxide (CrO3) at high temperature. The electrochemical properties of chromium oxide depended on the time and temperature during the heat treatment. Pure phase chromium oxide was prepared, and the effects of heat treatment time on the structures and electrochemical properties of Cr8O21 were systematically studied. The first discharge mechanism of chromium oxide in lithium batteries was explored, and the results were similar to that in lithium-sulfur batteries. The crystal phases and electrochemical properties of the prepared …


Nitrogen-Sulfur Co-Doped Porous Carbon Preparation And Its Application In Lithium-Sulfur Batteries, Gui-Xiang Zhao, Wail Hafiz Zaki Ahmed, Fu-Liang Zhu Dec 2021

Nitrogen-Sulfur Co-Doped Porous Carbon Preparation And Its Application In Lithium-Sulfur Batteries, Gui-Xiang Zhao, Wail Hafiz Zaki Ahmed, Fu-Liang Zhu

Journal of Electrochemistry

In recent years, lithium-sulfur (Li-S) batteries have been considered as a promising candidate for the next generation of energy storage system due to their ultrahigh theoretical capacity (1675 mAh·g-1) and energy density (2600 Wh·kg-1). However, the practical application of Li-S batteries is seriously limited by their insulating nature of sulfur, the shuttle effect of polysulfides (LiPSs), and volume expansion during charging and discharging. To overcome those disadvantages, one of the commonly methods is to infiltrate sulfur into porous conductive carbon framework, such as porous carbon, hollow carbon spheres, graphene, carbon nanotubes and some composites of the …