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Sample records for char forming processes

  1. A solid state NMR investigation of char forming processes in polymer degradation

    CERN Document Server

    Dick, C M

    2002-01-01

    A detailed knowledge of the condensed phase chemistry occurring in polymers exposed to elevated temperatures is crucial to understanding the behaviour of polymers exposed to fire. This is particularly true when trying to reduce polymer flammability by means of promoting char-forming reactions. Until recently, however, structural information on highly crosslinked chars and their precursors has been difficult to obtain, and as a consequence many degradation workers have merely labelled degradation residues as 'intractable'. However, the application of solid state NMR techniques developed in our laboratories for the structural characterisation of coals has provided a considerable insight into the structure and chemistry of polymer chars formed under both oxidative and non-oxidative conditions. A series of polymers including poly(vinyl chloride), poly(vinyl acetate), polyurethanes, polychloropene, cis and trans polyisoprene have been studied. These polymers have been used to describe the application of quantitati...

  2. Dwarf char, a new form of chars (the genus Salvelinus) in Lake Kronotskoe

    Science.gov (United States)

    Pavlov, S.D.; Pivovarov, E.A.; Ostberg, C.O.

    2012-01-01

    Lake Kronotskoe is situated in the Kronotskii State Nature Reserve and is a unique natural heritage of Kamchatka. The lake–river system of the reserve includes numerous springs and small streams and three large inflowing rivers, Listvennichnaya, Unana, and Uzon, which form the main bays of Lake Kronotskoe; one river (Kronotskaya) flows from the lake. This river is characterized by several rapids, which are assumed to be unsurmountable barriers for fish migration. The ichthyofauna of the lake has been isolated for a long time, and some endemic fishes appeared, including char of the genus Salvelinus and the residential form of red salmon Oncorhynchus nerka (the local name is kokanee). These species are perfect model objects to study microevolution processes. Char of Lake Kronotskoe are characterized by significant polymorphism and plasticity [1–3]; therefore, they are extremely valuable for studying the processes of speciation and form development. That is why the populations of char in Lake Kronotskoe are unique and attract special attention of researchers. 

  3. An investigation of the reactivity of chars formed in fluidized-bed gasifiers: equipment development and initial tests

    Energy Technology Data Exchange (ETDEWEB)

    A. Cousins; N. Paterson; D.R. Dugwell; R. Kandiyoti [Imperial College London, London (United Kingdom). Department of Chemical Engineering

    2006-03-15

    Chars formed during air and oxygen blown gasification processes have a low reactivity. This is due to changes that occur in the structure and morphology of the original coal during heating. In part, the changes depend on conditions prevailing during the pyrolysis stage and partly on the length of time spent at peak temperature. Previous work in this laboratory has highlighted that the gasification reactivity of a char depends on the conditions of its formation. This means that chars must be prepared under realistic conditions when conducting laboratory scale reactivity studies that are intended to support a larger scale development. This is not easy to do and requires the development of dedicated methods for preparing the char. In this paper, the development of a laboratory-scale test, based on a laboratory-scale spouted bed gasifier, is described that is able to prepare chars under conditions that represent those in an air-blown gasifier. The reactivity of the prepared chars is then examined to identify how the reactivity of the char varies within the envisaged operating window of the process. A feature of this apparatus is that the char formation time is known accurately, which has required the development of novel feeding and draining mechanisms. These enable the coal particles to be injected quickly into the reactor and the sand/char bed drained and quenched rapidly after a known residence time. The extent of char deactivation can be measured with residence times between 2 and 3600 s. In this paper, the validation of the experiment is described and some preliminary results are reported. 7 refs., 10 figs., 2 tabs.

  4. Co-gasification of tire and biomass for enhancement of tire-char reactivity in CO2 gasification process.

    Science.gov (United States)

    Lahijani, Pooya; Zainal, Zainal Alimuddin; Mohamed, Abdul Rahman; Mohammadi, Maedeh

    2013-06-01

    In this investigation, palm empty fruit bunch (EFB) and almond shell (AS) were implemented as two natural catalysts rich in alkali metals, especially potassium, to enhance the reactivity of tire-char through co-gasification process. Co-gasification experiments were conducted at several blending ratios using isothermal Thermogravimetric analysis (TGA) under CO2. The pronounced effect of inherent alkali content of biomass-chars on promoting the reactivity of tire-char was proven when acid-treated biomass-chars did not exert any catalytic effect on improving the reactivity of tire-char in co-gasification experiments. In kinetic studies of the co-gasified samples in chemically-controlled regime, modified random pore model (M-RPM) was adopted to describe the reactive behavior of the tire-char/biomass-char blends. By virtue of the catalytic effect of biomass, the activation energy for tire-char gasification was lowered from 250 kJ/mol in pure form 203 to 187 kJ/mol for AS-char and EFB-char co-gasified samples, respectively.

  5. Modeling and field observations of char bed processes in black liquor recovery boilers

    Energy Technology Data Exchange (ETDEWEB)

    Engblom, M.

    2010-07-01

    The char bed plays an important role in kraft black liquor combustion. Stable operation of the char bed promotes efficient and safe operation of the black liquor recovery boiler. It also plays a crucial role in the recovery of the pulping chemicals. Char bed operation involves controlling the char bed size and shape. Mathematical modeling based on computational fluid dynamics (CFD) haas been applied to recovery boilers for increased insights into the recovery furnace processes and to aid in the design of new boilers. So far, all CED-based char bed models reported in literature have used a fixed bed shape. This imposes restrictions on simulation of char bed burning by not considering inherently occurring changes in bed shape. In this thesis, a CED -based recovery furnace model is further developed to predict changes in bed shape. The new model is used in simulation of existing recovery boilers. The predictions of bed shape are compared with observations from real boilers. The furnace model is capable of correctly simulating the overall response of the char bed size to operational changes. This confirms the current quantitative overall understanding of char bed burning. In addition to modeling, visual observations of the char bed processes were made in this work. The observations provide validation data concerning the physical behavior of the char bed, and the findings from the observations can be used in further development of char bed models. Modeling and simulations of fundamental laboratory scale char bed experiments reported in literature are also carried out. The simulations complement the experimental data by providing detailed insights into gas phase reactions that can occur inside the gas boundary layer above a char bed. (orig.)

  6. Determination of the forms of calcium present in coal chars by Ca K-edge XANES with Synchrotron Radiation

    CERN Document Server

    Liu, Lijuan; Cui, Mingqi; Hu, Yongfeng; Zheng, Lei; Zhao, Yidong; Ma, Chenyan; Xi, Shibo; Yang, Dongliang; Guo, Zhiying; Wang, Jie

    2012-01-01

    This work is concerned with the Ca transformations during the pyrolysis of Ca(OH)2 or CaCO3-added coals. Ca K-edge X-ray absorption near edge structure (XANES) spectroscopy was applied to determine the forms of Ca in chars prepared from the pyrolysis of Ca-added coal. Results showed that Ca(OH)2 and CaSO4 existed in both the Ca(OH)2-added chars and the CaCO3-added chars, while CaS and CaO only existed in the chars prepared from the Ca(OH)2-added coal. Moreover, it was found that carboxyl Ca was formed during pyrolysis for either the Ca(OH)2-added coal or the CaCO3-added coals.

  7. Study on Char Forming Properties of ABS Flame Retarded by EG%可膨胀石墨阻燃ABS分解成炭性能研究

    Institute of Scientific and Technical Information of China (English)

    王志伟; 李荣勋; 周兵; 刘光烨

    2011-01-01

    The char forming properties of EG were studied by observing its macrostructure and microstructure. The thermogravimetric processes of EG and ABS/EG were studied by TG. The microstructure of flame-retardant ABS/EG was studied by SEM. The results show that EG has special "worm" structure after expansion, which imparts size effect and load effect to char layer of EG; flame-retardant ABS/EG can form compact and high temperature resistant char layer,which has heat insulation effect and oxygen insulation effect; the porous char layer structure can improve the structure stability of flame-retardant ABS/EG; the load catalyzing effect of EG char layer accelerates thermo-oxidation degradation and char crosslinking formation of ABS,meanwhile the char layer of EG can protect the char products of ABS, so it can increase the practical amount of char residue.%通过观测可膨胀石墨(EG)的宏观和微观结构,探讨了EG的分解成炭性能,利用热失重分析仪研究了EG与EG阻燃ABS的热失重行为,并采用扫描电镜观察了EG阻燃ABS膨胀炭层的微观结构.结果表明:EG自身膨胀后具有独特的"蠕虫"状结构,使EG炭层具有尺寸效应和负载作用;EG阻燃ABS形成了致密,耐高温的膨胀炭层,发挥隔氧、隔热作用,并且炭层呈现多孔的发泡堆砌结构,结构稳定性提高;EG膨胀炭层的负载值化作用促进了ABS的热氧降解反应和交联成炭反应,同时EG炭层能够保护ABS成炭产物,提高实际残炭量.

  8. Investigation of non-isothermal and isothermal gasification process of coal char using different kinetic model

    Institute of Scientific and Technical Information of China (English)

    Wang Guangwei; Zhang Jianliang; Shao Jiugang; Li Kejiang; Zuo Haibin

    2015-01-01

    Isothermal and non-isothermal gasification kinetics of coal char were investigated by using thermogravi-metric analysis (TGA) in CO2 atmosphere, and the experimental data were interpreted with the aids of random pore model (RPM), unreacted shrinking core model (URCM) and volume model (VM). With the increase of heating rate, gasification curve moves into high temperature zone and peak rate of gasification increases;with the increase of gasification temperature, gasification rate increases and the total time of gasification is shortened. The increase of both heating rate and gasification temperature could improve gasification process of coal char. Kinetics analysis indicates that experimental data agree better with the RPM than with the other two models. The apparent activation energy of non-isothermal and isother-mal gasification of coal char using RPM is 193.9 kJ/mol and 212.6 kJ/mol respectively, which are in accor-dance with reported data. Gasification process of coal char under different heating rates and different temperatures are predicted by the RPM derived in this study, and it is found that the RPM predicts the reaction process satisfactorily.

  9. The effect of chars and their water extractable organic carbon (WEOC) fractions on atrazine adsorption-desorption processes

    Science.gov (United States)

    Cavoski, I.; Jablonowski, N.; Burauel, P.; Miano, T.

    2012-04-01

    Chars are carbonaceous material produced from different type of biomass by pyrolysis. They are known as highly effective adsorbents for atrazine therefore limiting its degradation and its diffusion into the aqueous phase. The aim of the present work is to study the effects of different chars and char's derived WEOC on atrazine sorption-desorption processes. The five chars been used in this study derived from: 1) fast pyrolysis from hard wood (FP1); 2) flash pyrolysis from soft wood (FP2); 3) slow pyrolysis from deciduous wood (CC); 4) gasification from deciduous wood (GC) and 5) the market, purchased as activated charcoal standard (AC). Short-term batch equilibration tests were conducted to assess the sorption-desorption behavior of 14C-labeled atrazine on the chars, with a special focus on the desorption behavior using successive dilution method with six consecutive desorption step. Chars and their WEOC were physically and chemically characterized. Results demonstrate that biomass and pyrolysis process used to produce chars affect their physical and chemical properties, and atrazine adsorption-desorption behavior. Atrazine desorption resulted from the positive and competitive interactions between WEOC and chars surfaces. WEOC pool play important role in atrazine adsorption-desorption behavior. FP1 and FP2 with higher concentration of WEOC showed higher desorption rates, whereas GC, CC and AC with insignificant WEOC concentration strongly adsorb atrazine with low desorption rates. According to our results, when high WEOC pools chars are concerned, an increase in atrazine desorption can be observed but further studies would help in confirming the present results.

  10. Investigation on the catalytic effects of AAEM during steam gasification and the resultant char reactivity in oxygen using Shengli lignite at different forms

    Institute of Scientific and Technical Information of China (English)

    Jianxin Mi; Ningbo Wang; Mingfeng Wang; Pengju Huo; Dan Liu

    2015-01-01

    The purpose of this study is to investigate the catalytic effects of alkali and alkaline earth metallic species (AAEM) on char conversion during the gasification in steam and the changes in ex-situ char reactivity in oxygen after the gasification in steam using different forms (i.e. H-form, Na-form) of Shengli brown coal. The surface area, AAEM concentration and carbon crystallite of chars were obtained to understand the change in char reactivity. It was found that not only Na concentration and carbon structure were the main factors governing the char reactivity in the atmosphere of steam and oxygen, but also they interacted each other. The presence of Na could facilitate the formation of disordering carbon structure in char, and the amorphous carbon structure would in turn affect the distribution of Na and thus its catalytic performance. The surface area and pore volume had very little relationship with the char’s reactivity. Addi-tionally, the morphology of chars from different forms of coals were observed using scanning electron microscope (SEM).

  11. Adding the combination of CNTs and MoS{sub 2} into halogen-free flame retarding TPEE with enhanced the anti-dripping behavior and char forming properties

    Energy Technology Data Exchange (ETDEWEB)

    Zhong, Yuhua; Li, Maolin; Zhang, Luchong; Zhang, Xuewei; Zhu, Songwei; Wu, Wei, E-mail: wuwei@ecust.edu.cn

    2015-08-10

    Highlights: • Introduction the combination of the CNTs and MoS{sub 2} into P–N flame retarding TPEE. • Binary synergists for P–N flame retardants in TPEE. • Increase of char yield and form the stable carbonaceous char. - Abstract: In this paper, the nanocomposites thermoplastic polyester-ether elastomer (TPEE) with phosphorus–nitrogen (P–N) flame retardants, carbon nanotubes (CNTs) and molybdenum disulfide (MoS{sub 2}) was prepared by melt blending. TPEE containing P–N flame retardant, CNTs and MoS{sub 2} achieved UL94 V-0 rating due to the better barrier effect of the special structure. The structure was supported by the result of rheological properties. The thermal stability was studied by thermal gravimetric analysis (TGA) and char residue characterization was investigated by SEM–EDX measurements. The results demonstrated that the combination of CNTs and MoS{sub 2} results in the increase of char yield and the formation of the thermally stable char which can effectively prevent in the dripping behavior during the burning process.

  12. Manufacturing processes 4 forming

    CERN Document Server

    Klocke, Fritz

    2013-01-01

    This book provides essential information on metal forming, utilizing a practical distinction between bulk and sheet metal forming. In the field of bulk forming, it examines processes of cold, warm and hot bulk forming, as well as rolling and a new addition, the process of thixoforming. As for the field of sheet metal working, on the one hand it deals with sheet metal forming processes (deep drawing, flange forming, stretch drawing, metal spinning and bending). In terms of special processes, the chapters on internal high-pressure forming and high rate forming have been revised and refined. On the other, the book elucidates and presents the state of the art in sheet metal separation processes (shearing and fineblanking). Furthermore, joining by forming has been added to the new edition as a new chapter describing mechanical methods for joining sheet metals. The new chapter “Basic Principles” addresses both sheet metal and bulk forming, in addition to metal physics, plastomechanics and computational basics; ...

  13. Development of an advanced continuous mild gasification process for the production of coproducts. Task 4, System integration studies: Char upgrading

    Energy Technology Data Exchange (ETDEWEB)

    Jha, M.C.; McCormick, R.L.; Hogsett, R.F.; Rowe, R.M.; Anast, K.R.

    1991-12-01

    This document describes the results of Task 4 under which a 50 pound/hour char-to-carbon (CTC) process research unit (PRU) was designed in the second half of 1989, with construction completed in June 1990. The CTC PRU at Golden was operated for nearly one year during which 35 runs were completed for a total of nearly 800 hours of operation. Char methanation and carbon production reactor development activities are detailed in this report, as well as the results of integrated runs of the CTC process. Evaluation of the process and the carbon product produced is also included. It was concluded that carbon could be produced from mild gasification char utilizing the CTC process. Char methanation and membrane separation steps performed reasonably well and can scaled up with confidence. However, the novel directly heated reactor system for methane cracking did not work satisfactorily due to materials of construction and heat transfer problems, which adversely affected the quantity and quality of the carbon product. Alternative reactor designs are recommended.

  14. Influence of carbonization conditions on micro-pore structure of foundry formed coke produced with char

    Energy Technology Data Exchange (ETDEWEB)

    Jun Qiao; Jianjun Wu; Jingru Zu; Zhiyuan Gao; Guoli Zhou

    2009-07-01

    There are few studies on coke's micro-pore structure in recent years, however, micro-pore structure of foundry coke determines its macroscopically quality index and reactivity in cupola furnace. Effect of such factors on micro-pore structure were investigated under different carbonization conditions with certain ratio of raw materials and material forming process in this article as charging temperature (A); braised furnace time (B); heating rate of the first stage (C)and the second stage (D) and holding time of ultimate temperature (E). Research showed that charging temperature was the most influential factor on the coke porosity, pore volume, pore size and specific surface area. It is suggested that formation of plastic mass and releasing rate of volatile during carbonization period are two main factors on microstructure of foundry coke while charging temperature contributes most to the above factors. 6 refs., 4 figs., 9 tabs.

  15. The densification of bio-char: Effect of pyrolysis temperature on the qualities of pellets.

    Science.gov (United States)

    Hu, Qiang; Yang, Haiping; Yao, Dingding; Zhu, Danchen; Wang, Xianhua; Shao, Jingai; Chen, Hanping

    2016-01-01

    The densification of bio-chars pyrolyzed at different temperatures were investigated to elucidate the effect of temperature on the properties of bio-char pellets and determine the bonding mechanism of pellets. Optimized process conditions were obtained with 128MPa compressive pressure and 35% water addition content. Results showed that both the volume density and compressive strength of bio-char pellets initially decreased and subsequently increased, while the energy consumption increased first and then decreased, with the increase of pyrolysis temperature. The moisture adsorption of bio-char pellets was noticeably lower than raw woody shavings but had elevated than the corresponding char particles. Hydrophilic functional groups, particle size and binder were the main factors that contributed to the cementation of bio-char particles at different temperatures. The result indicated that pyrolysis of woody shavings at 550-650°C and followed by densification was suitable to form bio-char pellets for application as renewable biofuels.

  16. Effect of pyrolysis conditions and composition on the char structure and char yield of biomass chars

    DEFF Research Database (Denmark)

    Trubetskaya, Anna; Steibel, Markus; Spliethoff, Hartmut;

    The char yield as well as physical and chemical structure of chars generated from different types of biomass divided into five different particle size fractions from 50μm to 1mm were studied to better understand the influences of holding time, final temperatures and heating rates on the pyrolysis...... electron microscopy indicated different types of softening and melting of the biomass chars at all applied temperatures, heating rates and holding times, except for rice husks, which formed chars with a structure similar to the parent fuel. The char particles generated at high pyrolysis temperatures had...... many small pores and showed complete melting, while the biomasses like wheat straw and beech wood showed larger pores and not complete melting with the remaining carbon skeleton of different forms. FTIR analysis was conducted to estimate the remaining organic composition of the char consisting mainly...

  17. Quantum chemical study on the catalytic mechanism of Na/K on NO-char heterogeneous reactions during the coal reburning process

    Institute of Scientific and Technical Information of China (English)

    Zheng-cheng WEN; Zhi-hua WANG; Jun-hu ZHOU; Ke-fa CEN

    2009-01-01

    Quantum chemical simulation was used to investigate the catalytic mechanism of Na/K on NO-char heterogeneous reactions during the coal reburning process. Both NO-char and NO-NaYK reactions were considered as three-step processes in this calculation. Based on geometry optimizations made using the UB3LYP/6-31 G(d) method, the activation energies of NO-char and NO-Na/K reactions were calculated using the QC1SD(T)/6-3 i 1G(d, p) method; Results showed that the activation energy of the NO-Na/K reaction (107.9/82.0 kJ/mol) was much lower than that of the NO-char reaction (245.1 kJ/mol). The reactions of NaO/KO and Na2P/K2O reduced by char were also studied, and their thermodynamics were calculated using the UB3LYP/6-31G(d) method; Results showed that both Na and K can be refreshed easily and rapidly by char at high temperature during the coal rebuming process. Based on the calculations and analyses, the catalytic mechanism of Na/K on NO-char het-erogeneous reactions during the coal reburning process was clarified.

  18. Overview of the CHarring Ablator Response (CHAR) Code

    Science.gov (United States)

    Amar, Adam J.; Oliver, A. Brandon; Kirk, Benjamin S.; Salazar, Giovanni; Droba, Justin

    2016-01-01

    An overview of the capabilities of the CHarring Ablator Response (CHAR) code is presented. CHAR is a one-, two-, and three-dimensional unstructured continuous Galerkin finite-element heat conduction and ablation solver with both direct and inverse modes. Additionally, CHAR includes a coupled linear thermoelastic solver for determination of internal stresses induced from the temperature field and surface loading. Background on the development process, governing equations, material models, discretization techniques, and numerical methods is provided. Special focus is put on the available boundary conditions including thermochemical ablation and contact interfaces, and example simulations are included. Finally, a discussion of ongoing development efforts is presented.

  19. Formed HIP Can Processing

    Energy Technology Data Exchange (ETDEWEB)

    Clarke, Kester Diederik [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-07-27

    The intent of this report is to document a procedure used at LANL for HIP bonding aluminum cladding to U-10Mo fuel foils using a formed HIP can for the Domestic Reactor Conversion program in the NNSA Office of Material, Management and Minimization, and provide some details that may not have been published elsewhere. The HIP process is based on the procedures that have been used to develop the formed HIP can process, including the baseline process developed at Idaho National Laboratory (INL). The HIP bonding cladding process development is summarized in the listed references. Further iterations with Babcock & Wilcox (B&W) to refine the process to meet production and facility requirements is expected.

  20. Optimisation of slow-pyrolysis process conditions to maximise char yield and heavy metal adsorption of biochar produced from different feedstocks.

    Science.gov (United States)

    Hodgson, E; Lewys-James, A; Rao Ravella, S; Thomas-Jones, S; Perkins, W; Gallagher, J

    2016-08-01

    The objective of this work was to identify biomass feedstocks and optimum pyrolysis process conditions to produce a biochar capable of adsorbing metals from polluted groundwater. Taguchi experimental design was used to determine the effects of slow-pyrolysis process conditions on char yield and zinc adsorption. Treatments were repeated using six candidate feedstocks (Lolium perenne, Lolium perenne fibre, Miscanthus x giganteus, Salix viminalis, Fraxinus excelsior and Picea sitchensis) and the resultant chars were tested for metal adsorption performance. Chars produced from L. perenne and its extracted fibre displayed the greatest zinc adsorption performance and removed 83.27-92.96% respectively. Optimum process conditions in terms of both char yield and zinc adsorption performance were achieved from slow-pyrolysis at 300°C for 2h using a feedstock with a particle size of less than 1mm. PMID:27179953

  1. Predictive Method for Correct Identification of Archaeological Charred Grape Seeds: Support for Advances in Knowledge of Grape Domestication Process.

    Directory of Open Access Journals (Sweden)

    Mariano Ucchesu

    Full Text Available The identification of archaeological charred grape seeds is a difficult task due to the alteration of the morphological seeds shape. In archaeobotanical studies, for the correct discrimination between Vitis vinifera subsp. sylvestris and Vitis vinifera subsp. vinifera grape seeds it is very important to understand the history and origin of the domesticated grapevine. In this work, different carbonisation experiments were carried out using a hearth to reproduce the same burning conditions that occurred in archaeological contexts. In addition, several carbonisation trials on modern wild and cultivated grape seeds were performed using a muffle furnace. For comparison with archaeological materials, modern grape seed samples were obtained using seven different temperatures of carbonisation ranging between 180 and 340ºC for 120 min. Analysing the grape seed size and shape by computer vision techniques, and applying the stepwise linear discriminant analysis (LDA method, discrimination of the wild from the cultivated charred grape seeds was possible. An overall correct classification of 93.3% was achieved. Applying the same statistical procedure to compare modern charred with archaeological grape seeds, found in Sardinia and dating back to the Early Bronze Age (2017-1751 2σ cal. BC, allowed 75.0% of the cases to be identified as wild grape. The proposed method proved to be a useful and effective procedure in identifying, with high accuracy, the charred grape seeds found in archaeological sites. Moreover, it may be considered valid support for advances in the knowledge and comprehension of viticulture adoption and the grape domestication process. The same methodology may also be successful when applied to other plant remains, and provide important information about the history of domesticated plants.

  2. A burnout prediction model based around char morphology

    Energy Technology Data Exchange (ETDEWEB)

    T. Wu; E. Lester; M. Cloke [University of Nottingham, Nottingham (United Kingdom). Nottingham Energy and Fuel Centre

    2005-07-01

    Poor burnout in a coal-fired power plant has marked penalties in the form of reduced energy efficiency and elevated waste material that can not be utilized. The prediction of coal combustion behaviour in a furnace is of great significance in providing valuable information not only for process optimization but also for coal buyers in the international market. Coal combustion models have been developed that can make predictions about burnout behaviour and burnout potential. Most of these kinetic models require standard parameters such as volatile content, particle size and assumed char porosity in order to make a burnout prediction. This paper presents a new model called the Char Burnout Model (ChB) that also uses detailed information about char morphology in its prediction. The model can use data input from one of two sources. Both sources are derived from image analysis techniques. The first from individual analysis and characterization of real char types using an automated program. The second from predicted char types based on data collected during the automated image analysis of coal particles. Modelling results were compared with a different carbon burnout kinetic model and burnout data from re-firing the chars in a drop tube furnace operating at 1300{sup o}C, 5% oxygen across several residence times. An improved agreement between ChB model and DTF experimental data proved that the inclusion of char morphology in combustion models can improve model predictions. 27 refs., 4 figs., 4 tabs.

  3. Intensification of adsorption process by using the pyrolytic char from waste tires to remove chromium(Ⅵ) from wastewater

    Institute of Scientific and Technical Information of China (English)

    ZHOU Jie; YANG Yong-rong

    2004-01-01

    Pyrolysis has the potential of transforming waste into valuable recyclable products. Pyrolytic char(PC) is one of the most important products from the pyrolysis of used tires. One of the most significant applications for pyrolytic char recovered is used for the removal of Cr(Ⅵ) in the wastewater effluent to control waste by waste. The surface chemistry properties of surface element distribution / concentration and chemical structure were examined for the pyrolytic char and the commercial activated carbon(CAC) respectively. The results showed that surfaces of PC possesses a large amount of ester and hydrocarbon graft, whereas there are mainly carbon functional components of C-OH, C=O and COOH on the surface of CAC. Therefore the surface electronegativity of PC is lower than that of CAC in the water. The repulsive interactions between the surfaces of PC and the negatively charged Cr(Ⅵ) ion are weaker than that of CAC, which results in an intensification of the adsorption process by the utilization of PC. The adsorption isotherms of Cr(Ⅵ) ion on the two kinds of carbons were determined experimentally. The larger adsorption amount on the PC in the case of Cr(Ⅵ) may be attributed mainly to its special surface micro-chemical environment. The mechanism of the removal Cr(Ⅵ) from aqueous solution was assumed to be the integration of adsorption and redox reaction. The adsorption was the rate-controlled step for Cr(Ⅵ) removal. The adsorption of Cr(Ⅵ) has been identified as pseudo-second- order kinetics. The rate constants of adsorption have been evaluated.

  4. Reactivities of Shenfu Chars Toward Gasification with Carbon Dioxide

    Institute of Scientific and Technical Information of China (English)

    ZHANG Jia-wei; WEI Xian-yong; ZONG Zhi-min; WANG Tao-xia; XIE Rui-lun; DING Ming-jie; CAI Ke-ying; HUANG Yao-guo; GAO Jin-sheng; WU You-qing

    2007-01-01

    Five Shenfu char samples were prepared from Shenfu raw coal at different temperatures (950, 1100, 1200, 1300 and 1400 ℃) using a muffle furnace. Demineralization of the char samples was performed by treating them with 10% nitric acid for 10 min in a CEM Discover microwave reactor. The gasification of the chars, and corresponding demineralized chars, in a carbon dioxide (CO2) atmosphere was conducted in a Netzsch STA 409C131F temperature-programmed thermogravimetry apparatus. The effects of charring temperature and demineralization on the gasification reactivity of chars were systematically investigated. The results show that a char formed at a lower temperature is more reactive except for demineralized char formed at 1100 ℃, which is less reactive than char formed at 1200 ℃. Demineralization decreases the char reactivities toward gasification with CO2 to a small extent.

  5. Application of Wood Char in Processing Oolitic High-phosphorus Hematite for Phosphorus Removal

    Institute of Scientific and Technical Information of China (English)

    Hui-qing TANG; Yan-qi QIN; Teng-fei QI; Zhi-lei DONG; Qing-guo XUE

    2016-01-01

    Phosphorus removal from oolitic high-phosphorus hematite using direct reduction followed by melting sep-aration was investigated.At the direct reduction stage,highly volatile wood char was prepared by carbonizing j uj ube wood at 673 K for 2 h and was used as reducing agent.The results of the direct reduction tests show that at a tem-perature of 1 373 K,a char mixing ratio of 0�8,and a reduction time of 10-25 min,the briquettes reached a metal-lization degree of 80%-84% and a residual carbon content of 0�13-1�98 mass%.Phosphorus remained in the gangue as calcium phosphate after reduction.The results of the melting separation tests show that residual carbon in reduced briquette negatively affects the phosphorus content (w[P])in hot metal.When the reduced briquettes ob-tained under the aforementioned conditions were used for melting separation,hot metal suitable for basic oxygen steelmaking (w[P]<0�4 mass%)could not be obtained from metallic briquettes with a residual carbon content more than 1�0 mass%.In contrast,it could be obtained from metallic briquettes with residual carbon content less than 0�35 mass% by mixing with 2%-4% Na2 CO3 .

  6. An integrated process for hydrogen-rich gas production from cotton stalks: The simultaneous gasification of pyrolysis gases and char in an entrained flow bed reactor.

    Science.gov (United States)

    Chen, Zhiyuan; Zhang, Suping; Chen, Zhenqi; Ding, Ding

    2015-12-01

    An integrated process (pyrolysis, gas-solid simultaneous gasification and catalytic steam reforming) was utilized to produce hydrogen-rich gas from cotton stalks. The simultaneous conversion of the pyrolysis products (char and pyrolysis gases) was emphatically investigated using an entrained flow bed reactor. More carbon of char is converted into hydrogen-rich gas in the simultaneous conversion process and the carbon conversion is increased from 78.84% to 92.06% compared with the two stages process (pyrolysis and catalytic steam reforming). The distribution of tar components is also changed in this process. The polycyclic aromatic compounds (PACs) of tar are converted into low-ring compounds or even chain compounds due to the catalysis of char. In addition, the carbon deposition yield over NiO/MgO catalyst in the steam reforming process is approximately 4 times higher without the simultaneous process. The potential H2 yield increases from 47.71 to 78.19g/kg cotton stalks due to the simultaneous conversion process.

  7. Laser forming and welding processes

    CERN Document Server

    Yilbas, Bekir Sami; Shuja, Shahzada Zaman

    2013-01-01

    This book introduces model studies and experimental results associated with laser forming and welding such as laser induced bending, welding of sheet metals, and related practical applications. The book provides insight into the physical processes involved with laser forming and welding. The analytical study covers the formulation of laser induced bending while the model study demonstrates the simulation of bending and welding processes using the finite element method. Analytical and numerical solutions for laser forming and welding problems are provided.

  8. Charred olive stones: experimental and archaeological evidence for recognizing olive processing residues used as fuel

    NARCIS (Netherlands)

    Braadbaart, Freek; Marinova, E.; Sarpaki, A.

    2016-01-01

    After extracting oil from olives a residue is left usually referred to as the olive oil processing residue (OPR). This study explores the way in which ancient societies may have used OPR as fuel for fires to generate heat and the various issues that are related to the residues of this fuel. After dr

  9. Active sites in char gasification: Final technical report

    Energy Technology Data Exchange (ETDEWEB)

    Wojtowicz, M.; Lilly, W.D.; Perkins, M.T.; Hradil, G.; Calo, J.M.; Suuberg, E.M.

    1987-09-01

    Among the key variables in the design of gasifiers and combustors is the reactivity of the chars which must be gasified or combusted. Significant loss of unburned char is unacceptable in virtually any process; the provision of sufficient residence time for complete conversion is essential. A very wide range of reactivities are observed, depending upon the nature of the char in a process. The current work focuses on furthering the understanding of gasification reactivities of chars. It has been well established that the reactivity of char to gasification generally depends upon three principal factors: (1) the concentration of ''active sites'' in the char; (2) mass transfer within the char; and (3) the type and concentration of catalytic impurities in the char. The present study primarily addresses the first factor. The subject of this research is the origin, nature, and fate of active sites in chars derived from parent hydrocarbons with coal-like structure. The nature and number of the active sites and their reactivity towards oxygen are examined in ''model'' chars derived from phenol-formaldehyde type resins. How the active sites are lost by the process of thermal annealing during heat treatment of chars are studied, and actual rate for the annealing process is derived. Since intrinsic char reactivities are of primary interest in the present study, a fair amount of attention was given to the model char synthesis and handling so that the effect of catalytic impurities and oxygen-containing functional groups in the chemical structure of the material were minimized, if not completely eliminated. The project would not be considered complete without comparing characteristic features of synthetic chars with kinetic behavior exhibited by natural chars, including coal chars.

  10. Predictive Method for Correct Identification of Archaeological Charred Grape Seeds: Support for Advances in Knowledge of Grape Domestication Process

    OpenAIRE

    Ucchesu, Mariano; Orrù, Martino; Grillo, Oscar; Venora, Gianfranco; Paglietti, Giacomo; Ardu, Andrea; Bacchetta, Gianluigi

    2016-01-01

    The identification of archaeological charred grape seeds is a difficult task due to the alteration of the morphological seeds shape. In archaeobotanical studies, for the correct discrimination between Vitis vinifera subsp. sylvestris and Vitis vinifera subsp. vinifera grape seeds it is very important to understand the history and origin of the domesticated grapevine. In this work, different carbonisation experiments were carried out using a hearth to reproduce the same burning conditions that...

  11. Combustion of char-coal waste pellets for high efficiency and low NO{sub x}. Quarterly report, 1 December 1994--28 February 28, 1995

    Energy Technology Data Exchange (ETDEWEB)

    Rajan, S. [Southern Illinois Univ., Carbondale, IL (United States)

    1995-12-31

    High efficiencies can be obtained from combined cycle power plants where fuel gas produced in a carbonizer is used to power the topping cycle turbines, while the residual char is burnt to raise steam for the bottoming Rankine cycle plant. Illinois coals are excellent fuels for these high efficiency power plants as the sulfur in the fuel gas is removed in the carbonization process by adding dolomite, thus producing a clean burning fuel gas. The residual char has essentially no volatiles, and is of low density. Because of these characteristics the char requires a longer residence time for efficient combustion. This research is directed towards improving the residence time of the char by pelletizing it with a waste coal, while at the same time reducing the sulfur dioxide emissions from the char combustion. During this quarter, extensive experimentation has been performed to determine the char-gob waste proportions necessary for forming pellets with desirable compression strength for feeding into the circulating fluidized bed combustor. Carbonizer char-gob coal pellets have been made with 5, 10 and 15 weight percent of cornstarch binder. Based on the test data presented, it is concluded that 10--15% weight percent of binder will be required when pelletizing char-gob coal waste mixtures containing 30-40 percent by weight of gob coal. During the next quarter, these pellets will be made in larger quantities and their combustion and emissions properties will be evaluated in a bench scale 4-inch diameter circulating fluidized bed combustor.

  12. STUDY OF ACTIVATION OF COAL CHAR

    Energy Technology Data Exchange (ETDEWEB)

    E.M. Suuberg; I. Kulaots; I Aarna; M. Callejo; A. Hsu

    2003-12-31

    of this study, it was noted in a preliminary way how the use of different oxidizing environments would lead to very different porosity development in the same char. There did not seem to be a link to the overall inherent reactivity of the gas-char combination to the pattern of porosity development. In another portion of this study, it was observed that the expected pattern of porosity development could be seen, as a function of whether the process was carried out in a pure chemical kinetic control regime (Zone I) or in a partially mass transfer control regime (Zone II). This portion of the study was useful in suggesting that the unburned carbon from many practical pulverized coal combustion processes had actually emerged from a Zone II environment. This confirms other published hypotheses, and strongly suggests that the material does not survive the boiler environment because it was produced in a purely oxygen mass transfer limited zone (so-called Zone III) or because it was simply so unreactive that it could not burn up in the allotted time (a pure Zone I argument). Moreover, it is believed that the very rapid initial opening of porosity that is revealed by the rapid disappearance of nitrogen and carbon dioxide accessible porosity may be associated with a very thin surface layer of pyrolytically-formed carbon that effectively blocks the bulk char structure from nitrogen. Once removed by low extent of burn-off this phenomenon disappears. Finally, the project turned to comparing the relative influences of the starting coal and the oxidizing environment on the nature of porosity that was developed. Once again, the Argonne Premium coal suite served as a source of chars that would be representative of the broad range of coals found an utilized in the US. The conclusion is that the starting coal has a profound influence upon the ability of an oxidizing agent to develop porosity in the char. This is the single most important factor. Beyond this, however, there was a

  13. Structure Based Predictive Model for Coal Char Combustion

    Energy Technology Data Exchange (ETDEWEB)

    Robert Hurt; Joseph Calo; Robert Essenhigh; Christopher Hadad

    2000-12-30

    technical discussion organized into chapters whose organization is dictated by the nature of the research performed. Chapter 2 is entitled 'Experimental Work on Char Structure, Properties, and Reactivity', and focuses on fundamental structural studies at Brown using both phenollformaldehyde resin chars as model carbons and real coal chars. This work includes the first known in site high resolution TEM studies of carbonization processes, and some intriguing work on 'memory loss', a form of interaction between annealing and oxidation phenomena in chars. Chapter 3 entitled 'Computational Chemistry of Aromatic Oxidation Pathways' presents in detail the OSU work targeted at understanding the elementary molecular pathways of aromatic oxidation. Chapter 4 describes the 'Mesoscale Structural Models', using a combination of thermodynamic (equilibrium) approaches based on liquid crystal theory and kinetic simulations accounting for the effects of limited layer mobility in many fossil fuel derived carbons containing cross-linking agents. Chapter 5 entitled 'Combustion Modeling' presents work on extinction in the late stages of combustion and the development and features of the CBK8 model.

  14. Particle-based characterisation of pulverised coals and chars for carbon burnout studies

    Energy Technology Data Exchange (ETDEWEB)

    Gibbins, J.R.; Seitz, M.H.; Kennedy, S.M.; Beeley, T.J.; Riley, G.S. [Imperial College of Science, Technology and Medicine, London (United Kingdom). Mechanical Engineering Department

    1999-07-01

    The study of individual particle properties, as opposed to averaged behaviour of differing particles, was carried out for the combustion of coals and chars using optical microscopy and digital image processing. Chars from entrained flow reactors and corresponding pulverized fuel samples were characterized to examine possible char particle origins for real heterogeneous particles. 7 refs., 5 figs., 1 tab.

  15. Formation, Structure and Properties of Amorphous Carbon Char from Polymer Materials in Extreme Atmospheric Reentry Environments

    Science.gov (United States)

    Lawson, John W.

    2010-01-01

    Amorphous carbonaceous char produced from the pyrolysis of polymer solids has many desirable properties for ablative heat shields for space vehicles. Molecular dynamics simulations are presented to study the transformation of the local atomic structure from virgin polymer to a dense, disordered char [1]. Release of polymer hydrogen is found to be critical to allow the system to collapse into a highly coordinated char structure. Mechanisms of the char formation process and the morphology of the resulting structures are elucidated. Thermal conductivity and mechanical response of the resulting char are evaluated [2]. During reenty, the optical response and oxidative reactivity of char are also important properties. Results of ab initio computations of char optical functions [3] and char reactivity [4] are also presented.

  16. 污水处理工艺对污泥热解半焦热解特性的影响%Effect of wastewater treatment processes on the pyrolysis properties of the chars from sewage sludge pyrolysis

    Institute of Scientific and Technical Information of China (English)

    王俊; 解立平; 高建东; 曹占平

    2013-01-01

    The pyrolysis properties of five different pyrolysis chars,derived from the pyrolysis of five different sewage sludges from three wastewater treatment plants under 450 ℃ , were studied by thermal gravimetric analysis with a heating rate of 10 ℃/min in nitrogen atmosphere. The results show that the pyrolysis processes of the five chars all can be divided into four stages: the stages of water release, slow weight loss, volatile release and residue decomposition respectively. Both the anaerobic process of wastewater treatment processes and sludge anaerobic digestion make the organic compounds in char complicated. The sludge anaerobic digestion improves the pyrolysis property of char, but the processes of " anaerobic + aerobic" and "aerobic + anaerobic" in wastewater treatment processes make the properties decrease,in which the influence of " aerobic + anaerobic " on the pyrolysis property of sludge is different from that of char; the third stage of char pyrolysis corresponds to the fourth stage of the sludge pyrolysis to some degree. The pyrolysis mechanisms of the five chars have been studied with Coats-Redfern method. It indicates that the mechanism functions of the five chars are not identical each other, but the pyrolysis activation energies of chars are higher than that of sludges.%通过在升温速率10℃/min和氮气氛围下的热重实验,对来自3个污水处理厂的5种污泥在450℃下热解制得半焦的热解特性进行了研究.结果表明,5种半焦的热解过程均为水分析出、缓慢失重、挥发分析出和残余物分解4个阶段.污水处理工艺中的厌氧过程和污泥厌氧消化使半焦中的有机物复杂化;污泥厌氧消化改善了半焦的热解性能,污水处理工艺中的“厌氧+好氧”和“好氧+厌氧”过程则降低了半焦的热解性能,其中“好氧+厌氧”过程对半焦热解性能的影响异于其对污泥热解性能的影响;半焦热解时的第三阶段与污泥的第四阶段

  17. Thermal decomposition and gasification of biomass pyrolysis gases using a hot bed of waste derived pyrolysis char.

    Science.gov (United States)

    Al-Rahbi, Amal S; Onwudili, Jude A; Williams, Paul T

    2016-03-01

    Chars produced from the pyrolysis of different waste materials have been investigated in terms of their use as a catalyst for the catalytic cracking of biomass pyrolysis gases during the two-stage pyrolysis-gasification of biomass. The chars were produced from the pyrolysis of waste tyres, refused derived fuel and biomass in the form of date stones. The results showed that the hydrocarbon tar yields decreased significantly with all the char materials used in comparison to the non-char catalytic experiments. For example, at a cracking temperature of 800°C, the total product hydrocarbon tar yield decreased by 70% with tyre char, 50% with RDF char and 9% with biomass date stones char compared to that without char. There was a consequent increase in total gas yield. Analysis of the tar composition showed that the content of phenolic compounds decreased and polycyclic aromatic hydrocarbons increased in the product tar at higher char temperatures. PMID:26773946

  18. Low-energy and chemical-free activation of pyrolytic tire char and its adsorption characteristics.

    Science.gov (United States)

    Quek, Augustine; Balasubramanian, Rajasekhar

    2009-06-01

    It is generally known that the solid char obtained from pyrolysis of scrap rubber tires can be used as an adsorbent for several applications such as wastewater treatment. In this study, scrap tires were first pyrolyzed under nitrogen (N2) or carbon dioxide (CO2) gas under various temperatures to produce char. The char was activated in situ by post-pyrolysis oxygenation (PPO) at different temperature ranges as soon as the pyrolysis process was completed. Elemental and spectroscopic analyses showed significant zinc content in the char after PPO. Batch-mode removal of aqueous copper (Cu) using the chars revealed that, for N2 and CO2, the optimum condition for pyrolysis was at 550 degrees C and for activation was from 550 to 250 degrees C. Although CO2-pyrolyzed char had lower Cu and lead (Pb) removal than N2-pyrolyzed char, it had higher char yields. For both N2- and CO2-pyrolyzed char, activation with PPO improved their heavy metal removal efficiencies significantly compared with unactivated char. PPO chars had much faster removal rates and higher Cu removal compared with both pyrolyzed, unactivated char and commercial activated carbons. PMID:19603742

  19. Microanalysis of vitrous char and associated polymers: reference and ancient assemblages

    Science.gov (United States)

    Allue, E.; Bonnamy, S.; Courty, M. M.; Gispert I Guirado, F.

    2012-12-01

    Formation of vitrous char that occur in ancient charcoal assemblages have remained unsolved. Laboratory experiments refuted vitrification to resulting from high temperature charring of green or resinous wood. This puzzling problem has been refreshed by showing the association to the charcoal and vitrous char of plastics that were originally supposed to only be produced by petroleum industry. Extraction of similar polymers within geological glassy products from cosmic airbursts has suggested impact processes to possibly forming the carbonaceous polymorphs. The pulverisation at the ground in the Angles village (French Eastern Pyrenees) following the 2011 August 2nd high altitude meteor explosion of exotic debris with vitrous char and polymers, just alike the puzzling ones of the geological and archaeological records, has provided potential reference materials. We present here their microanalysis by Environmental SEM with EDS, Raman micro-spectrometry and FTIR, XRD, TEM, ICP-MS and isotope analyses. The characterization helps elucidating how the carbonaceous polymorphs formed by transient heating and transient high pressure of atmospheric aerosols. Under TEM the vesicular, dense, vitrous char show high structural organization with a dense pattern of nano-sized graphitized domains, metals and mineral inclusions. The coupled Raman-ESEM has allowed identifying a complex pattern at micro scales of ordered "D" peak at 1320-1350 cm-1 and the graphitic, ordered peak at 1576-1590 cm-1, in association to amorphous and poorly graphitic ordered carbon. The later occurs within plant cells that have been extracted from the dense vitrous char by performing controlled combustion under nitrogen up to 1000°C. In contrast, the brittle, vesicular vitrous char and the polymers encountered at the rear of the pulverised airburst debris reveal to be formed of agglutinated micro spherules of amorphous carbon with rare crystallized carbon nano-domains and scattered mineral inclusions. They

  20. CONCEPTUAL ANALYSIS OF FORMING PROCESSES PROJECT TEAM

    OpenAIRE

    Celovalnikova, E.

    2010-01-01

    In the article the conceptual analysis of the stages of forming of project team and processes is conducted management its project activity with the purpose of achievement of successful completion of the put aims in a project.

  1. Gasification of biomass chars in steam-nitrogen mixture

    Energy Technology Data Exchange (ETDEWEB)

    Haykiri-Acma, H. [Department of Chemical Engineering, Chemical and Metallurgical Engineering Faculty, Istanbul Technical University, 34469 Maslak, Istanbul (Turkey)]. E-mail: hanzade@itu.edu.tr; Yaman, S. [Department of Chemical Engineering, Chemical and Metallurgical Engineering Faculty, Istanbul Technical University, 34469 Maslak, Istanbul (Turkey); Kucukbayrak, S. [Department of Chemical Engineering, Chemical and Metallurgical Engineering Faculty, Istanbul Technical University, 34469 Maslak, Istanbul (Turkey)

    2006-05-15

    Some agricultural and waste biomass samples such as sunflower shell, pinecone, rapeseed, cotton refuse and olive refuse were first pyrolyzed in nitrogen, and then, their chars were gasified in a gas mixture of steam and nitrogen. Experiments were performed using the thermogravimetric analysis technique. Pyrolysis of the biomass samples was performed at a heating rate of 20 K/min from ambient to 1273 K in a dynamic nitrogen atmosphere of 40 cm{sup 3} min{sup -1}. The obtained chars were cooled to ambient temperature and then gasified up to 1273 K in a dynamic atmosphere of 40 cm{sup 3} min{sup -1} of a mixture of steam and nitrogen. Derivative thermogravimetric analysis profiles from gasification of the chars were derived, and the mass losses from the chars were interpreted in terms of temperature. It was concluded that gasification characteristics of biomass chars were fairly dependent on the biomass properties such as ash and fixed carbon contents and the constituents present in the ash. Different mechanisms in the three temperature intervals, namely water desorption at lower temperatures, decomposition of hydroxide minerals to oxide minerals and formation of carbon monoxide at medium temperatures and production of hydrogen at high temperatures govern the behavior of the char during the gasification process. The chars from pinecone and sunflower shell could be easily gasified under the mentioned conditions. In order to further raise the conversion yields, long hold times should be applied at high temperatures. However, the chars from rapeseed and olive refuse were not gasified satisfactorily. Low ash content and high fixed carbon content biomass materials are recommended for use in gasification processes when char from pyrolysis at elevated temperatures is used as a feedstock.

  2. Low temperature waste form process intensification

    Energy Technology Data Exchange (ETDEWEB)

    Fox, K. M. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Cozzi, A. D. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Hansen, E. K. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Hill, K. A. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2015-09-30

    This study successfully demonstrated process intensification of low temperature waste form production. Modifications were made to the dry blend composition to enable a 50% increase in waste concentration, thus allowing for a significant reduction in disposal volume and associated costs. Properties measurements showed that the advanced waste form can be produced using existing equipment and processes. Performance of the waste form was equivalent or better than the current baseline, with approximately double the amount of waste incorporation. The results demonstrate the feasibility of significantly accelerating low level waste immobilization missions across the DOE complex and at environmental remediation sites worldwide.

  3. Systematic Process Improvement of Sheet Metal Forming Processes

    Science.gov (United States)

    Carleer, Bart; Stippak, Michael

    2011-08-01

    The design of a forming process of sheet metal forming parts is a complex issue. Many boundary conditions must be fulfilled and many considerations must be made to come to a successful solution. Elimination wrinkles and splits very often need contrary measures. Many times the approach to come to a successful solution is an iterative process which is also dependent on the person who deals with the job. Generally this job has been solved with help of simulation software. AutoForm developed a methodology, systematic process improvement, to systematically approach this job. The systematic process improvement is a standardized way to effectively design forming processes. This systematical approach reduces the number of loops, gives transparency of the different solution statements and makes it easier to pass the work to a colleague. As a result the development of a forming process can be done faster, more reliable and less dependent on individuals. The systematic process improvement will be illustrated on the design of forming process of an automotive part.

  4. Experimental Study of Hydrogasification of Lignite and Subbituminous Coal Chars

    Directory of Open Access Journals (Sweden)

    Stanisław Gil

    2015-01-01

    Full Text Available The experimental facility for pressure hydrogasification research was adapted to the pressure of 10 MPa and temperature of 1300 K, which ensured repeatability of results and hydrogen heating to the process temperature. A hydrogasification reaction of chars produced from two rank coals was investigated at temperatures up to 1173 K, pressures up to 8 MPa, and the gas flow rates of 0.5–5 dmn3/min. Reactivity of the “Szczerców” lignite char was found to be slightly higher than that of the subbituminous “Janina” coal char produced under the same conditions. A high value of the char reactivity was observed to a certain carbon conversion degree, above which a sharp drop took place. It was shown that, to achieve proper carbon conversion, the hydrogasification reaction must proceed at a temperature above 1200 K.

  5. Prehistoric cereal foods from Greece and Bulgaria: investigation of starch microstructure in experimental and archaeological charred remains

    OpenAIRE

    Valamoti, Soultana-Maria; Samuel, Delwen; Bayram, Mustafa; Elena MARINOVA

    2008-01-01

    Abstract In order to investigate ancient cereal cooking practices, the microstructure of preserved starch in charred ground cereal remains recovered from prehistoric sites in Greece and Bulgaria has been analysed. A comparative modern set of cooked and subsequently charred cereals was produced. By scanning electron microscopy it is demonstrated that, under some conditions, distinctive cooked starch structure survives the charring process. Charring alone can occasionall...

  6. Hencky's model for elastomer forming process

    Science.gov (United States)

    Oleinikov, A. A.; Oleinikov, A. I.

    2016-08-01

    In the numerical simulation of elastomer forming process, Henckys isotropic hyperelastic material model can guarantee relatively accurate prediction of strain range in terms of large deformations. It is shown, that this material model prolongate Hooke's law from the area of infinitesimal strains to the area of moderate ones. New representation of the fourth-order elasticity tensor for Hencky's hyperelastic isotropic material is obtained, it possesses both minor symmetries, and the major symmetry. Constitutive relations of considered model is implemented into MSC.Marc code. By calculating and fitting curves, the polyurethane elastomer material constants are selected. Simulation of equipment for elastomer sheet forming are considered.

  7. The effect of char structure on burnout during pulverized coal combustion at pressure

    Energy Technology Data Exchange (ETDEWEB)

    Liu, G.; Wu, H.; Benfell, K.E.; Lucas, J.A.; Wall, T.F.

    1999-07-01

    An Australian bituminous coal sample was burnt in a drop tube furnace (DTF) at 1 atm and a pressurized drop tube furnace (PDTF) at 15 atm. The char samples were collected at different burnout levels, and a scanning electron microscope was used to examine the structures of chars. A model was developed to predict the burnout of char particles with different structures. The model accounts for combustion of the thin-walled structure of cenospheric char and its fragmentation during burnout. The effect of pressure on reaction rate was also considered in the model. As a result, approximately 40% and 70% cenospheric char particles were observed in the char samples collected after coal pyrolysis in the DTF and PDTF respectively. A large number of fine particles (< 30 mm) were observed in the 1 atm char samples at burnout levels between 30% and 50%, which suggests that significant fragmentation occurred during early combustion. Ash particle size distributions show that a large number of small ash particles formed during burnout at high pressure. The time needed for 70% char burnout at 15 atm is approximately 1.6 times that at 1 atm under the same temperature and gas environment conditions, which is attributed to the different pressures as well as char structures. The overall reaction rate for cenospheric char was predicted to be approximately 2 times that of the dense chars, which is consistent with previous experimental results. The predicted char burnout including char structures agrees reasonably well with the experimental measurements that were obtained at 1 atm and 15 atm pressures.

  8. Simulation of Glass Fiber Forming Processes

    DEFF Research Database (Denmark)

    Von der Ohe, Renate; Yue, Yuanzheng

    Two glass fiber forming processes have been simulated using FEM, which are the drawing of continuous glass fibers for reinforcement purposes and the spinning of discontinuous glass fibers - stone wool for insulation. The aim of this work was to set up a numerical model for each process, and to use......, and parametric studies have been made. Several properties that characterize the process have been calculated, and the relationship between the fictive temperature and the cooling rate of the fibers has been found. The model for the discontinuous fiber spinning was brought to the limits of the commercial code...... this model in finding relationships between the production conditions and the resulting fiber properties. For both processes, a free surface with large deformation and radiative and convective heat transfer must be taken into account. The continuous fiber drawing has been simulated successfully...

  9. Casting Forming Process Simulation of Aluminum Flywheel

    Directory of Open Access Journals (Sweden)

    QIAO Yin-hu

    2013-04-01

    Full Text Available Simulating the forming process of casting in this paper, according to two kinds of analysis results of the designed model, the reasonable structure, pouring temperature and riser selecting of the flywheel are determined to ensure the quality of castings. The using of simulation software before the actual molding can get rid of the possible hidden danger, to shorten the product development cycle, save money, improve product quality.

  10. Influence of pyrolysis conditions on the structure and gasification reactivity of biomass chars

    Energy Technology Data Exchange (ETDEWEB)

    E. Cetin; B. Moghtaderi; R. Gupta; T.F. Wall [University of Newcastle, Callaghan, NSW (Australia). Discipline of Chemical Engineering, Faculty of Engineering and Built Environment, School of Engineering

    2004-11-01

    The physical and chemical structure as well as gasification reactivities of chars generated from several biomass species (i.e. pinus radiata, eucalyptus maculata and sugar cane bagasse) were studied to gain insight into the role of heating rate and pressure on the gasification characteristics of biomass chars. Char samples were generated in a suite of reactors including a wire mesh reactor, a tubular reactor, and a drop tube furnace. Scanning electron microscopy analysis, X-ray diffractometry, digital cinematography and surface area analysis were employed to determine the impact of operating conditions on the char structure. The global gasification reactivities of char samples were also determined for a range of pressures between 1 and 20 bar using pressurised thermogravimetric analysis technique. Char reactivities were found to increase with increasing pyrolysis heating rates and decreasing pyrolysis pressure. It was found that under high heating rates the char particles underwent plastic deformation (i.e. melted) developing a structure different to that of the virgin biomass. Pressure was also found to influence the physical and chemical structures of char particles. The difference in the gasification reactivities of biomass chars at pressure was found to correlate well with the effect of pyrolysis pressure on the graphitisation process in the biomass char structure. 29 refs., 18 figs., 2 tabs.

  11. Waste Form Features, Events, and Processes

    Energy Technology Data Exchange (ETDEWEB)

    R. Schreiner

    2004-10-27

    The purpose of this report is to evaluate and document the inclusion or exclusion of the waste form features, events and processes (FEPs) with respect to modeling used to support the Total System Performance Assessment for License Application (TSPA-LA). A screening decision, either Included or Excluded, is given for each FEP along with the technical bases for screening decisions. This information is required by the Nuclear Regulatory Commission (NRC) in 10 CFR 63.114 (d, e, and f) [DIRS 156605]. The FEPs addressed in this report deal with the issues related to the degradation and potential failure of the waste form and the migration of the waste form colloids. For included FEPs, this analysis summarizes the implementation of the FEP in TSPA-LA, (i.e., how the FEP is included). For excluded FEPs, this analysis provides the technical bases for exclusion from TSPA-LA (i.e., why the FEP is excluded). This revision addresses the TSPA-LA FEP list (DTN: MO0407SEPFEPLA.000 [DIRS 170760]). The primary purpose of this report is to identify and document the analyses and resolution of the features, events, and processes (FEPs) associated with the waste form performance in the repository. Forty FEPs were identified that are associated with the waste form performance. This report has been prepared to document the screening methodology used in the process of FEP inclusion and exclusion. The analyses documented in this report are for the license application (LA) base case design (BSC 2004 [DIRS 168489]). In this design, a drip shield is placed over the waste package and no backfill is placed over the drip shield (BSC 2004 [DIRS 168489]). Each FEP may include one or more specific issues that are collectively described by a FEP name and a FEP description. The FEP description may encompass a single feature, process or event, or a few closely related or coupled processes if the entire FEP can be addressed by a single specific screening argument or TSPA-LA disposition. The FEPs are

  12. Evaluation of control strategies in forming processes

    Directory of Open Access Journals (Sweden)

    Calmano Stefan

    2015-01-01

    Full Text Available Products of forming processes are subject to quality fluctuations due to uncertainty in semi-finished part properties as well as process conditions and environment. An approach to cope with these uncertainties is the implementation of a closed-loop control taking into account the actual product properties measured by sensors or estimated by a mathematical process model. Both methods of uncertainty control trade off with a financial effort. In case of sensor integration the effort is the cost of the sensor including signal processing as well as the design and manufacturing effort for integration. In case of an estimation model the effort is mainly determined by the time and knowledge needed to derive the model, identify the parameters and implement the model into the PLC. The risk of mismatch between model and reality as well as the risk of wrong parameter identification can be assumed as additional uncertainty (model uncertainty. This paper evaluates controlled and additional uncertainty by taking into account process boundary conditions like the degree of fluctuations in semi-finished part properties. The proposed evaluation is demonstrated by the analysis of exemplary processes.

  13. Failure Prediction in Bulk Metal Forming Process

    Directory of Open Access Journals (Sweden)

    Ameen Topa

    2014-01-01

    Full Text Available An important concern in metal forming is whether the desired deformation can be accomplished without defects in the final product. Various ductile fracture criteria have been developed and experimentally verified for a limited number of cases of metal forming processes. These criteria are highly dependent on the geometry of the workpiece and cannot be utilized for complicated shapes without experimental verification. However, experimental work is a resource hungry process. This paper proposes the ability of finite element analysis (FEA software such as LS-DYNA to pinpoint the crack-like flaws in bulk metal forming products. Two different approaches named as arbitrary Lagrangian-Eulerian (ALE and smooth particle hydrodynamics (SPH formulations were adopted. The results of the simulations agree well with the experimental work and a comparison between the two formulations has been carried out. Both approximation methods successfully predicted the flow of workpiece material (plastic deformation. However ALE method was able to pinpoint the location of the flaws.

  14. Different characteristics of char and soot in the atmosphere and their ratio as an indicator for source identification in Xi'an, China

    Directory of Open Access Journals (Sweden)

    Y. M. Han

    2010-01-01

    Full Text Available Numerous definitions and analytical techniques for elemental (or black carbon (EC have been published in the scientific literature, but still no generally accepted interdisciplinary definition exists. EC is not a single chemical compound, but is mainly composed of two parts of carbon contents: combustion residues from pyrolysis and combustion emissions formed via gas-to-particle conversion. Accordingly EC is subdivided into two classes: char and soot. Char is defined as carbonaceous materials obtained by heating organic substances and formed directly from pyrolysis, or as an impure form of graphitic carbon obtained as a residue when carbonaceous material is partially burned or heated with limited access of air. Soot is defined as only those carbon particles that form at high temperature via gas-phase processes. Since the different classes of EC have different chemical and physical properties, their optical light-absorbing properties differ, so that it is essential to differentiate them in the environment. The thermal optical reflectance (TOR method was used to differentiate between char-EC and soot-EC according to its stepwise thermal evolutional oxidation of different carbon fractions under different temperatures and atmosphere. Char-EC and soot-EC are operationally defined as EC1-OP and EC2+EC3 (EC1, EC2 and EC3 corresponding to carbon fractions evolved at 550, 700 and 800 °C in a 98% He/2% O2 atmosphere, respectively, respectively. One year of observations of the daily and seasonal variations of carbonaceous particles were conducted in Xi'an, China in 2004 to demonstrate the different characteristics of char and soot in the atmosphere. Total carbon (TC, organic carbon (OC, EC and char-EC showed similar seasonal trends, with high concentrations in winter and low concentrations in summer, while soot-EC revealed relatively small seasonal variations, with maximum concentration (1.85±0.72 μg m−3 in spring and minimum

  15. Comparison of the carbon-sequestering abilities of pineapple leaf residue chars produced by controlled combustion and by field burning.

    Science.gov (United States)

    Leng, L Y; Husni, M H A; Samsuri, A W

    2011-11-01

    This study was undertaken to compare the chemical properties and yields of pineapple leaf residue (PLR) char produced by field burning (CF) with that produced by a partial combustion of air-dried PLR at 340 °C for 3 h in a furnace (CL). Higher total C, lignin content, and yield from CL as well as the presence of aromatic compounds in the Fourier Transform Infrared spectra of the char produced from CL suggest that the CL process was better in sequestering C than was the CF process. Although the C/N ratio of char produced from CL was low indicating a high N content of the char, the C in the char produced from CL was dominated by lignin suggesting that the decomposition of char produced from CL would be slow. To sequester C by char application, the PLR should be combusted in a controlled process rather than by burning in the field. PMID:21958525

  16. Comparison of the carbon-sequestering abilities of pineapple leaf residue chars produced by controlled combustion and by field burning.

    Science.gov (United States)

    Leng, L Y; Husni, M H A; Samsuri, A W

    2011-11-01

    This study was undertaken to compare the chemical properties and yields of pineapple leaf residue (PLR) char produced by field burning (CF) with that produced by a partial combustion of air-dried PLR at 340 °C for 3 h in a furnace (CL). Higher total C, lignin content, and yield from CL as well as the presence of aromatic compounds in the Fourier Transform Infrared spectra of the char produced from CL suggest that the CL process was better in sequestering C than was the CF process. Although the C/N ratio of char produced from CL was low indicating a high N content of the char, the C in the char produced from CL was dominated by lignin suggesting that the decomposition of char produced from CL would be slow. To sequester C by char application, the PLR should be combusted in a controlled process rather than by burning in the field.

  17. Biochemical stability of sewage sludge chars and their impact on soil organic matter of a Mediterranean Cambisol

    Science.gov (United States)

    Paneque, Marina; María De la Rosa, José; Aragón, Carlos; Kern, Jürgen; Knicker, Heike

    2016-04-01

    Transformation of sewage sludge (SS) into char achieves sludge hygienisation, which is necessary prior its application into agricultural soils. The pyrolysis of SS increases its stability in a degree which depends on the thermal treatment used. Thus, chars produced by using hydrothermal carbonization are typically more stable than normal soil organic matter (SOM), but less stable than chars from dry pyrolysis (Libra et al., 2011). Addition of highly-recalcitrant SS-chars to soil will likely increase its carbon sequestration potential; however the fertilizing properties of SS may be compromised due to its alteration during the pyrolysis. The main goal of this work was to investigate the biochemical recalcitrance of two 13C-enriched SS-chars once applied in a Mediterranean Cambisol as well as to evaluate their impact on the SOM quality and carbon stability. Thus, we studied the distribution of 13C between plants and soil after the addition of the 13C-enriched chars (2 atm%) to the soil. Therefore, we performed a greenhouse incubation experiment, using a Mediterranean Cambisol as matrix and tested the following treatments: control (soil alone), raw SS, SS-hydrochar, SS-pyrochar. The SS was produced in a pilot-scale waste-water plant and enriched with 13C by the addition of 13C-glucose during the treatment. The amendment was only applied to the upper 2 cm of the soil matrix where it accounted for 5% of its dry weight. Per pot, 25 seeds of Lolium perenne were sowed and incubated under controlled conditions. The biomass production as well as the concentration of 13C in leaves and roots was determined after 1, 2 and 5 months. The partitioning of the 13C between soil and plant and its transformation into bioavailable forms were monitored by stable isotopic mass spectrometry. The 13C-enrichment of the chars allowed the use of solid-state 13C NMR spectroscopy as a means for the detection of chemical alterations of the chars during their aging. Libra J., Ro K., Kammann C

  18. Production of activated carbon from TCR char

    Science.gov (United States)

    Stenzel, Fabian; Heberlein, Markus; Klinner, Tobias; Hornung, Andreas

    2016-04-01

    The utilization of char for adsorptive purposes is known since the 18th century. At that time the char was made of wood or bones and used for decoloration of fluids. In the 20th century the production of activated carbon in an industrial scale was started. The today's raw materials for activated carbon production are hard coal, peat, wood or coconut shells. All these materials entail costs especially the latter. Thus, the utilization of carbon rich residues (biomass) is an interesting economic opportunity because it is available for no costs or even can create income. The char is produced by thermo-catalytic reforming (TCR®). This process is a combination of an intermediate pyrolysis and subsequently a reforming step. During the pyrolysis step the material is decomposed in a vapor and a solid carbon enriched phase. In the second step the vapor and the solid phase get in an intensive contact and the quality of both materials is improved via the reforming process. Subsequently, the condensables are precipitated from the vapor phase and a permanent gas as well as oil is obtained. Both are suitable for heat and power production which is a clear advantage of the TCR® process. The obtained biochar from the TCR® process has special properties. This material has a very low hydrogen and oxygen content. Its stability is comparable to hard coal or anthracite. Therefore it consists almost only of carbon and ash. The latter depends from input material. Furthermore the surface structure and area can be influenced during the reforming step. Depending from temperature and residence time the number of micro pores and the surface area can be increased. Preliminary investigations with methylene blue solution have shown that a TCR® char made of digestate from anaerobic digestion has adsorptive properties. The decoloration of the solution was achieved. A further influencing factor of the adsorption performance is the particle size. Based on the results of the preliminary tests a

  19. Subcellular distribution of trace elements and liver histology of landlocked Arctic char (Salvelinus alpinus) sampled along a mercury contamination gradient.

    Science.gov (United States)

    Barst, Benjamin D; Rosabal, Maikel; Campbell, Peter G C; Muir, Derek G C; Wang, Xioawa; Köck, Günter; Drevnick, Paul E

    2016-05-01

    We sampled landlocked Arctic char (Salvelinus alpinus) from four lakes (Small, 9-Mile, North, Amituk) in the Canadian High Arctic that span a gradient of mercury contamination. Metals (Hg, Se, Tl, and Fe) were measured in char tissues to determine their relationships with health indices (relative condition factor and hepatosomatic index), stable nitrogen isotope ratios, and liver histology. A subcellular partitioning procedure was employed to determine how metals were distributed between potentially sensitive and detoxified compartments of Arctic char livers from a low- and high-mercury lake (Small Lake and Amituk Lake, respectively). Differences in health indices and metal concentrations among char populations were likely related to differences in feeding ecology. Concentrations of Hg, Se, and Tl were highest in the livers of Amituk char, whereas concentrations of Fe were highest in Small and 9-Mile char. At the subcellular level we found that although Amituk char had higher concentrations of Tl in whole liver than Small Lake char, they maintained a greater proportion of this metal in detoxified fractions, suggesting an attempt at detoxification. Mercury was found mainly in potentially sensitive fractions of both Small and Amituk Lake char, indicating that Arctic char are not effectively detoxifying this metal. Histological changes in char livers, mainly in the form of melano-macrophage aggregates and hepatic fibrosis, could be linked to the concentrations and subcellular distributions of essential or non-essential metals.

  20. Catalytic gasification of char from co-pyrolysis of coal and biomass

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Wenkui [State key Laboratory of Multi-phase Complex system, the Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100080 (China); Graduate University, Chinese Academy of Sciences, Beijing 100080 (China); Song, Wenli; Lin, Weigang [State key Laboratory of Multi-phase Complex system, the Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100080 (China)

    2008-09-15

    The catalytic gasification of char from co-pyrolysis of coal and wheat straw was studied. Alkali metal salts, especially potassium salts, are considered as effective catalysts for carbon gasification by steam and CO{sub 2}, while too expensive for industry application. The herbaceous type of biomass, which has a high content of potassium, may be used as an inexpensive source of catalyst by co-processing with coal. The reactivity of chars from co-pyrolysis of coal and straw was experimentally examined. The chars were prepared in a spout-entrained reactor with different ratios of coal to straw. The gasification characteristics of chars were measured by thermogravimetric analysis (TGA). The co-pyrolysis chars revealed higher gasification reactivity than that of char from coal, especially at high level of carbon conversion. The influence of the alkali in the char and the pyrolysis temperature on the reactivity of co-pyrolysis char was investigated. The experimental results show that the co-pyrolysis char prepared at 750 C have the highest alkali concentration and reactivity. (author)

  1. Coal devolatilization and char conversion under suspension fired conditions in O2/N2 and O2/CO2 atmospheres

    DEFF Research Database (Denmark)

    Jensen, Anker Degn; Brix, Jacob; Jensen, Peter Arendt

    2010-01-01

    was burned at 1573 K and 1673 K a faster conversion was found in N2 suggesting that the lower molecular diffusion coefficient of O2 in CO2 lowers the char conversion rate when external mass transfer influences combustion. The reaction of char with CO2 was not observed to have an influence on char conversion......The aim of the present investigation is to examine differences between O2/N2 and O2/CO2 atmospheres during devolatilization and char conversion of a bituminous coal at conditions covering temperatures between 1173 K and 1673 K and inlet oxygen concentrations between 5 and 28 vol.%. The experiments...... indicates that a shift from air to oxy-fuel combustion does not influence the devolatilization process significantly. Char combustion experiments yielded similar char conversion profiles when N2 was replaced with CO2 under conditions where combustion was primarily controlled by chemical kinetics. When char...

  2. Studying the specific features pertinent to combustion of chars obtained from coals having different degrees of metamorphism and biomass chars

    Science.gov (United States)

    Bestsennyi, I. V.; Shchudlo, T. S.; Dunaevskaya, N. I.; Topal, A. I.

    2013-12-01

    Better conditions for igniting low-reaction coal (anthracite) can be obtained, higher fuel burnout ratio can be achieved, and the problem of shortage of a certain grade of coal can be solved by firing coal mixtures and by combusting coal jointly with solid biomass in coal-fired boilers. Results from studying the synergetic effect that had been revealed previously during the combustion of coal mixtures in flames are presented. A similar effect was also obtained during joint combustion of coal and wood in a flame. The kinetics pertinent to combustion of char mixtures obtained from coals characterized by different degrees of metamorphism and the kinetics pertinent to combustion of wood chars were studied on the RSK-1D laboratory setup. It was found from the experiments that the combustion rate of char mixtures obtained from coals having close degrees of metamorphism is equal to the value determined as a weighted mean rate with respect to the content of carbon. The combustion rate of char mixtures obtained from coals having essentially different degrees of metamorphism is close to the combustion rate of more reactive coal initially in the process and to the combustion rate of less reactive coal at the end of the process. A dependence of the specific burnout rate of carbon contained in the char of two wood fractions on reciprocal temperature in the range 663—833 K is obtained. The combustion mode of an experimental sample is determined together with the reaction rate constant and activation energy.

  3. Effect of the coal particle size on pyrolysis and char reactivity for two types of coal and demineralized coal

    Energy Technology Data Exchange (ETDEWEB)

    Wenkui Zhu; Wenli Song; Weigang Lin [Chinese Academy of Sciences, Beijing (China). State Key Laboratory of Multi-phase Complex System

    2008-07-15

    A better understanding of the influence of particle size on pyrolysis and char reactivity is of crucial importance in optimizing the integrated process combining coal topping (coal fast pyrolysis) with char gasification. Different size fractions of two types of coal and demineralized coal were pyrolyzed in a spouted bed. The resulting chars were characterized by X-ray diffraction, and char reactivity was determined in a thermogravimetric analyzer (TGA). Within the range of particle sizes investigated, an increase in particle size results in an increase of char yield, which may be caused by the secondary reactions of volatile matters inside the coal particles. No significant difference in crystallinity was observed for the chars from different size fractions of the parent coals, while more crystallinity was observed for the chars from demineralized coals, which suggests that minerals in the coal play a role in the reduction of char crystallinity during pyrolysis. Char reactivity for raw coals decreased with the increasing of the particle size. For the demineralized coal samples, the change in char reactivity with the increasing of the particle size was reduced. Both the secondary reactions of volatiles and mineral distribution are believed to cause the influence of coal particle size on char reactivity. 19 refs., 7 figs., 3 tabs.

  4. Preparation and characterization of activated carbon from demineralized tyre char

    Science.gov (United States)

    Manocha, S.; Prasad, Guddu R.; Joshi, Parth.; Zala, Ranjitsingh S.; Gokhale, Siddharth S.; Manocha, L. M.

    2013-06-01

    Activated carbon is the most adsorbing material for industrial waste water treatment. For wider applications, the main consideration is to manufacture activated carbon from low cost precursors, which are easily available and cost effective. One such source is scrap tyres. Recently much effort has been devoted to the thermal degradation of tyres into gaseous and liquid hydrocarbons and solid char residue, all of which have the potential to be processed into valuable products. As for solid residue, char can be used either as low-grade reinforcing filler or as activated carbon. The product recovered by a typical pyrolysis of tyres are usually, 33-38 wt% pyrolytic char, 38-55 wt% oil and 10-30 wt% solid fractions. In the present work activated carbon was prepared from pyrolyzed tyre char (PC). Demineralization involves the dissolution of metal into acids i.e. HCl, HNO3 and H2SO4 and in base i.e. NaOH. Different concentration of acid and base were used. Sodium hydroxide showed maximum amount of metal oxide removal. Further the concentration of sodium hydroxide was varied from 1N to 6N. As the concentration of acid are increased demineralization increases. 6N Sodium hydroxide is found to be more effective demineralising agent of tyre char.

  5. Disintegration of beech wood char during thermal conversion

    DEFF Research Database (Denmark)

    Hindsgaul, Claus

    were limited by Knudsen diffusion through the pits in the wood cell walls for degrees of conversion by gasification up to at least 0.5. A computer model of slab gasification based on the diffusion measurements successfully predicted the mass loss rate during diffusion-limited gasification of beech wood......In the present work the processes occurring in the structures of slowly pyrolysed beech wood char during thermal gasification have been investigated. Emphasis was put on physical changes and gas transport properties during conversion. The highly anisotropic structure of wood was preserved in its...... char. Direct observation of the microscopic char structures during gasification in CO2 at 735 QC showed that the basic structure was nearly intact up to degrees of conversion of 0.6—0.7. Uni-axial measurements of diffusion coefficients and permeabilities with a Wicke-Kallenbach cell revealed...

  6. Fast pyrolysis char - Assessment of alternative uses within the bioliq® concept.

    Science.gov (United States)

    Funke, A; Niebel, A; Richter, D; Abbas, M M; Müller, A-K; Radloff, S; Paneru, M; Maier, J; Dahmen, N; Sauer, J

    2016-01-01

    Experiments with a process development unit for fast pyrolysis of biomass residues of 10kgh(-1) have been performed to quantify the impact of two different product recovery options. Wheat straw, miscanthus and scrap wood have been used as feedstock. A separate recovery of char increases the organic oil yield as compared to a combined recovery of char and organic condensate (OC). Furthermore, it allows for an alternative use of the byproduct char which represents an important product fraction for the high ash biomass residues under consideration. The char produced shows little advantage over its biomass precursor when considered as energy carrier due to its high ash content. Significant value can be added by demineralizing and activating the char. The potential to increase the economic feasibility of fast pyrolysis is shown by an assessment of the bioliq® process chain. PMID:26609947

  7. Influence of fast pyrolysis conditions on yield and structural transformation of biomass chars

    DEFF Research Database (Denmark)

    Trubetskaya, Anna; Jensen, Peter Arendt; Jensen, Anker Degn;

    2015-01-01

    Fast pyrolysis of biomass (wood, straw, rice husk) and its major components (cellulose, hemicellulose, lignin) was conducted in a wire mesh reactor. The aim of this study was to understand the influence of temperature (350-1400 ° C), heating rate (10-3000 ° C/s), particle size (0.05-2 mm...... that the heat treatment temperature had a larger influence on the char yield than the heating rate. Scanning electron microscopy indicated different types of biomass char plasticization influenced by the applied temperatures, heating rates, particle sizes and holding times, except for the rice husk char...... that formed chars with a structure similar to the parental fuel at all conditions. The less severe morphological changes of rice husk char were attributed to a high silica content....

  8. NC INCREMENTAL SHEET METAL FORMING PROCESS AND VERTICAL WALL SQUARE BOX FORMING

    Institute of Scientific and Technical Information of China (English)

    Zhou Liuru; Mo Jianhua; Xiao Xiangzhi

    2004-01-01

    The forming principle and deformation analysis of NC incremental sheet metal forming process as well as the process planning, experiment and key process parameters of vertical wall square box forming are presented. Because the deformation of sheet metal only occurs around the tool head and the deformed region is subjected to stretch deformation, the deformed region of sheet metal thins, and surface area increases. Sheet metal forming stepwise is to lead to the whole sheet metal deformation. The forming half-apex angle θ and corner radius R are the main process parameters in NC incremental forming of vertical wall square box. According to sine law, a vertical wall square box can't be formed by NC incremental sheet metal forming process in a single process, rather, it must be formed in multi processes. Thus, the parallel line type tool path process method is presented to form the vertical wall square box, and the experiment and analysis are made to verify it.

  9. Active carbons from low temperature conversion chars

    International Nuclear Information System (INIS)

    Hulls obtained from the fruits of five tropical biomass have been subjected to low temperature conversion process and their chars activated by partial physical gasification to produce active carbons. The biomass are T. catappa, B. nitida, L leucophylla, D. regia and O. martiana. The bulk densities of the samples ranged from 0.32 g.cm3 to 0.52 g.cm3. Out of the samples T. catappa recorded the highest cellulose content (41.9 g.100g-1), while O. martiana contained the highest lignin content (40.7 g.100g-1). The ash of the samples were low (0.5 - 4.4%). The percentage of char obtained after conversion were high (33.7% - 38.6%). Active carbons obtained from T. catappa, D. regia and O. martiana, recorded high methylene blue numbers and iodine values. They also displayed good micro- and mesostructural characteristics. Micropore volume (Vmicro) was between 0.33cm3.g-1 - 0.40cm3.g-1, while the mesopore volume(Vmeso) was between 0.05 cm3.g-1 - 0.07 cm3.g-1. The BET specific surface exceeds 1000 m2.g-1. All these values compared favourably with high grade commercial active carbons. (author)

  10. Production and Characterization of Bio-Char from the Pyrolysis of Empty Fruit Bunches

    Directory of Open Access Journals (Sweden)

    Mohamad A. Sukiran

    2011-01-01

    Full Text Available Problem statement: The palm oil industry generates an abundance of oil palm biomass such as the Empty Fruit Bunch (EFB, shell, frond, trunk and Palm Oil Mill Effluent (POME. For 88 million tones of Fresh Fruit Bunch (FFB processed in 2008, the amount of oil palm biomass was more than 26 million tones. Studies about production of bio-char from oil palm biomass are still lacking in Malaysia. So, this study was aimed to: (i determine the effect of pyrolysis temperatures on bio-char yield (ii characterize the bio-char obtained under different pyrolysed temperatures. Approach: In this study, pyrolysis of EFB was conducted using a fluidized fixed bed reactor. The effect of pyrolysis temperatures on bio-char yield was investigated. The pyrolysis temperature used ranged from 300-700°C. The elemental analysis, calorific value, surface area and total pore volume of the bio-char were determined. Results: The highest bio char yield of 41.56% was obtained at an optimum pyrolysis temperature of 300°C with particle size of 91-106 μm and the heating rate of 30°C min-1. The calorific values of bio-char ranged from 23-26 MJ kg-1. Conclusion: It was found that the bio-char products can be characterized as carbon rich, high calorific value and potential solid biofuels.

  11. Lowland river systems - processes, form and function

    DEFF Research Database (Denmark)

    Pedersen, M. L.; Kronvang, B.; Sand-Jensen, K.;

    2006-01-01

    Present day river valleys and rivers are not as dynamic and variable as they used to be. We will here describe the development and characteristics of rivers and their valleys and explain the background to the physical changes in river networks and channel forms from spring to the sea. We seek to ...

  12. Alternative Forms of Compound Fractional Poisson Processes

    Directory of Open Access Journals (Sweden)

    Luisa Beghin

    2012-01-01

    Full Text Available We study here different fractional versions of the compound Poisson process. The fractionality is introduced in the counting process representing the number of jumps as well as in the density of the jumps themselves. The corresponding distributions are obtained explicitly and proved to be solution of fractional equations of order less than one. Only in the final case treated in this paper, where the number of jumps is given by the fractional-difference Poisson process defined in Orsingher and Polito (2012, we have a fractional driving equation, with respect to the time argument, with order greater than one. Moreover, in this case, the compound Poisson process is Markovian and this is also true for the corresponding limiting process. All the processes considered here are proved to be compositions of continuous time random walks with stable processes (or inverse stable subordinators. These subordinating relationships hold, not only in the limit, but also in the finite domain. In some cases the densities satisfy master equations which are the fractional analogues of the well-known Kolmogorov one.

  13. Processes, Forms Of Sport Management System

    Directory of Open Access Journals (Sweden)

    Gheorghe Jinga

    2013-05-01

    Full Text Available The process of instructing the sportsmen has always been a complex and thorough activity, that requests profundity, professional sensitivity and bonding. The main characters in this process are played by managers, coaches, trainers, methodists, psychologists, sociologists, technicians who establish and hand over theoretical knowledge, abilitiesand skills for the sportsmen. In this way is being created the environment for instructing and highlighting the physical, technical, tactical and psychic potential of the participants in competitions. The training process of the sportsmen is more and more headed towards the integral and deep internalization of the instructive components, based on the interconnections between the elements of modern sport science.

  14. Thermogravimetric study on the influence of structural, textural and chemical properties of biomass chars on CO2 gasification reactivity

    International Nuclear Information System (INIS)

    The present investigation aims to examine the influence of textural, structural and chemical properties of biomass chars on the CO2 gasification rate. Various lignocellulosic biomass chars were prepared under the same conditions. Different analytical techniques were used to determine the char properties such as Scanning Electronic Microscopy, nitrogen adsorption manometry, Raman spectroscopy and X Ray Fluorescence. Gasification tests were carried out in a thermobalance under 20% CO2 in nitrogen at 800 °C. Significant differences of the total average reactivity were observed with a factor of 2 between the prepared chars. Moreover, different behaviors of gasification rate profiles versus conversion were obtained. This difference of behavior appeared to be correlated with the biomass char properties. Hence, up to 70% of conversion, the gasification rate was shown to depend on the char external surface and the potassium content. At higher conversion ratio, a satisfactory correlation between the Catalytic Index and the average gasification rate was identified. The results highlight the importance of knowing both textural and structural properties and mineral contents of biomass chars to predict fuel reactivity during CO2 gasification processes. Such behavior prediction is highly important in the gasifiers design for char conversion. - Highlights: • CO2 gasification reactivity of various lignocellulosic chars were examined. • Chars properties affect strongly samples gasification behavior. • Initial gasification rate is affected by external surface, K content and D3/G ratio. • Gasification rate behavior depends on the Alkali index at high conversion

  15. Coal pyrolysis and char burnout under conventional and oxy-fuel conditions

    Energy Technology Data Exchange (ETDEWEB)

    Al-Makhadmeh, L.; Maier, J.; Scheffknecht, G. [Stuttgart Univ. (Germany). Institut fuer Verfahrenstechnik und Dampfkesselwesen

    2009-07-01

    Coal utilization processes such as combustion or gasification generally involve several steps i.e., the devolatilization of organic materials, homogeneous reactions of volatile matter with the reactant gases, and heterogeneous reactions of the solid (char) with the reactant gases. Most of the reported work about coal pyrolysis and char burnout were performed at low temperatures under environmental conditions related to the air firing process with single particle tests. In this work, coal combustion under oxy-fuel conditions is investigated by studying coal pyrolysis and char combustion separately in practical scales, with the emphasis on improving the understanding of the effect of a CO{sub 2}-rich gas environment on coal pyrolysis and char burnout. Two coals, Klein Kopje a medium volatile bituminous coal and a low-rank coal, Lausitz coal were used. Coal pyrolysis in CO{sub 2} and N{sub 2} environments were performed for both coals at different temperatures in an entrained flow reactor. Overall mass release, pyrolysis gas concentrations, and char characterization were performed. For char characterization ultimate analysis, particle size, and BET surface area were measured. Chars for both coals were collected at 1150 C in both CO{sub 2} and N{sub 2} environments. Char combustion was performed in a once-through 20 kW test facility in O{sub 2}/CO{sub 2} and O{sub 2}/N{sub 2} atmospheres. Besides coal quality, oxygen partial pressure was chosen as a variable to study the effect of the gas environment on char burnout. In general, it is found that the CO{sub 2} environment and coal rank have a significant effect on coal pyrolysis and char burnout. (orig.)

  16. Ash liberation from included minerals during combustion of pulverized coal: the relationship with char structure and burnout

    Energy Technology Data Exchange (ETDEWEB)

    Wu, H.; Wall, T.; Liu, G.; Bryant, G. [University of Newcastle, Callaghan, NSW (Australia). CRC for Black Coal Utilization and Dept. of Chemical Engineering

    1999-12-01

    In this study, the float fraction ({lt} specific gravity of 2.0) of a size cut (63-90 {mu}m) bituminous coal was combusted in a drop tube furnace (DTF) at a gas temperature of 1300{degree}C under an atmosphere of air, to investigate the ash liberation at five coal burnoff levels (35.5%, 54.3%, 70.1%, 87.1% and 95.6%). The data indicated that char structure determines the ash liberation at different burnoff levels. Fragmentation of porous char was found to be the determinative mechanism for formation of fine ash during the early and middle stages of char combustion, while coalescence of included mineral matter determines the coarse ash formed in the later stages of combustion. The investigation confirmed that the char morphology and structure play a key role in determining char fragmentation, char burnout history, and the ash liberation during combustion. 35 refs., 5 figs., 2 tabs.

  17. 水葫芦水热碳化过程中焦炭物化结构演变特性%Forming property of water hyacinth hydro-char physicochemical structure during hydrothermal carbonation

    Institute of Scientific and Technical Information of China (English)

    高英; 袁巧霞; 陈汉平; 王贤华

    2015-01-01

    以水葫芦为原料,利用高温高压反应釜对240℃、停留时间0.5~24.0 h下水热炭物化结构的演变特性进行分析.研究发现:不同停留时间下焦炭的产率及O/C和H/C原子比的范围分别为22.17%~31.67%,0.19~0.45和0.94~1.51,焦炭的热值范围为16.83~20.63 M J/kg .通过对焦炭进行分析测试,探讨水热炭的生成机理以及炭微球的形成机制,结果表明:4.0h后延长停留时间对焦炭的化学特性没有明显的影响;但是随着时间的进一步延长,水热炭却表现出较好的结构特性,可以观察到焦炭表面有大量微球的生成,具有典型的核壳结构,炭微球的表面含有大量的活性含氧官能团,内部则为低活性的含氧官能团;水热炭比表面积随着时间的延长先增大后减小.%Hydrothermal carbonization of water hyacinth was conducted in an autoclave from 0 .5 h to 24 .0 h at 240 ℃ ,the physicochemical characteristics of water hyacinth hydro‐char was investigated . T he results show that hydro‐char yield ,oxygen/carbon ratio ,and hydrogen/carbon ratio in all hydro‐char products are 22 .17% to 31 .67% ,0 .19 to 0 .45 ,and 0 .94 to 1 .51 ,respectively ,and higher heat‐ing value of hydro‐char products is 16 .83 to 20 .63 MJ/kg .To further investigate the hydrothermal formation mechanism and carbon microspheres formation mechanism ,it is indicated that there′s no significant change in the chemical properties of hydro‐char after 4 .0 h ,but with time increasing ,the hydro‐char show better structural characteristics . The surface generates a large number of micro‐spheres with a typical core‐shell structure and the surface of carbon microspheres contains large a‐mounts of reactive oxygen‐containing functional groups ,compares with low activity of the internal ox‐ygen‐containing functional groups ,and specific surface area increases first ,and then decreases

  18. Chemical processes in star forming regions

    OpenAIRE

    Caselli, Paola

    2005-01-01

    This paper will review the basic concepts of gas-phase and grain surface chemistry of dense molecular clouds, where low mass and high mass stars form. The chemistry of cold pre-stellar cloud cores, where molecular freeze-out and deuterium fractionation dominate, will be presented. Then, following cloud evolution after protostellar birth, hot core and shock chemistry will be discussed in view of recent observations. A brief summary of the chemistry in protoplanetary disks will also be furnishe...

  19. Hyperfinite Dirichlet Forms and Stochastic Processes

    CERN Document Server

    Albeverio, Sergio; Herzberg, Frederik

    2011-01-01

    This monograph treats the theory of Dirichlet forms from a comprehensive point of view, using 'nonstandard analysis'. Thus, it is close in spirit to the discrete classical formulation of Dirichlet space theory by Beurling and Deny (1958). The discrete infinitesimal setup makes it possible to study the diffusion and the jump part using essentially the same methods. This setting has the advantage of being independent of special topological properties of the state space and in this sense is a natural one, valid for both finite- and infinite-dimensional spaces. The present monograph provides a tho

  20. Forms, Sources and Processes of Trust

    NARCIS (Netherlands)

    Nooteboom, B.

    2006-01-01

    This chapter reviews some key points in the analysis of trust, based on Nooteboom (2002)i.The following questions are addressed.What can we have trust in?What is the relation between trust and control?What are the sources of trust? And what are its limits?By what process is trust built up and broken

  1. Identification of a charred corpse through dental records

    OpenAIRE

    Isamara Geandra Cavalcanti Caputo; Jair Naves dos Reis; Teresa Cristina Pantozzi Silveira; Marco Aurélio Guimarães; Ricardo Henrique Alves da Silva

    2011-01-01

    Introduction: Forensic Dentistry is an area of Dentistry related to Law. Among its goals is the execution of human identification, defined as the process of determining the person’s identity. The forensic dentist uses, in this process, ante-mortem records and data for comparison with post-mortem information obtained from the examination of the body. Objective: To describe the process of identification of a charred corpse by using dental records. Case report: The human material remained from a...

  2. Kohnen's limit process for real-analytic Siegel modular forms

    OpenAIRE

    Bringmann, Kathrin; Raum, Martin; Richter, Olav K.

    2012-01-01

    Kohnen introduced a limit process for Siegel modular forms that produces Jacobi forms. He asked if there is a space of real-analytic Siegel modular forms such that skew-holomorphic Jacobi forms arise via this limit process. In this paper, we initiate the study of harmonic skew-Maass-Jacobi forms and harmonic Siegel-Maass forms. We improve a result of Maass on the Fourier coefficients of harmonic Siegel-Maass forms, which allows us to establish a connection to harmonic skew-Maass-Jacobi forms....

  3. Role of char during reburning of nitrogen oxides. Seventh quarterly progress report, April 1, 1995--June 30, 1995

    Energy Technology Data Exchange (ETDEWEB)

    Wei-Yin Chen; Te-Chang Lu [Univ. of Mississippi, University, MS (United States); Fan, L.T.; Yashima, M. [Kansas State Univ., Manhattan, KS (United States)

    1995-08-11

    The progress in this quarter includes four parts. In the first segment, the implications of our data reported in the List quarter are discussed further. BET N{sub 2} surface area does not seems to be the only contributing factor to the remarkable activity of lignite char during reburning, and chars of different origins probably have different controlling steps in the overall surface reaction mechanisms. Unlike NO reduction in the gas phase, oxygen inhibits the heterogeneous mechanisms. The second part of this report justifies the use of our laminar flow reactor system for the measurement of reaction rate. Dispersion model is used in the analysis. An expression relating the rate constant with the experimentally obtainable NO conversion for our flow reactor have been derived. Rates of NO/char reaction for six series of experiments have been measured over the temperature range 800 to 1100{degrees}C. These six series of experiments have been conducted with two different chars, one bituminous coal char and one lignite char, and three different levels of feed NO concentrations, 200, 400 and 1000 ppm. Results from the comparison of char activities suggest that, in the absence of O{sub 2} and CO{sub 2}, the origin of char is not a significant factor for NO reduction. The CO/CO{sub 2} ratio in the products is higher than one under all test conditions, but the ratio increases with increasing feed NO concentrations. Recoveries of oxygen form the lignite char at temperatures above 1050{degrees}C is higher than 1 indicating gasification of organic oxygen in the char. Surface areas of selected chars after devolatilization and after reburning have been analyzed by BET in N{sub 2}. Results indicated char surface area changes after reburning, which is caused either by the higher temperature of reburning or by surface reaction.

  4. Mixed waste treatment using the ChemChar thermolytic detoxification technique

    Energy Technology Data Exchange (ETDEWEB)

    Kuchynka, D. [Mirage Systems, Sunnyvale, CA (United States)

    1995-10-01

    The diversity of mixed waste matrices contained at Department of Energy sites that require treatment preclude a single, universal treatment technology capable of handling sludges, solids, heterogeneous debris, aqueous and organic liquids and soils. This report describes the ChemChar thermolytic detoxification process. The process is a thermal, chemically reductive technology that converts the organic portion of mixed wastes to a synthesis gas, while simultaneously absorbing volatile inorganics on a carbon-based char.

  5. Kinetics characteristics of straw semi-char gasification with carbon dioxide.

    Science.gov (United States)

    Xiao, Ruirui; Yang, Wei

    2016-05-01

    The gasification process has promising potential as a solution for the current global energy problem. Kinetics characteristics of straw semi-char gasification were investigated. The main influence factors of gasification, which include bio-char particle size, pyrolysis temperature and pyrolysis atmosphere, were studied. The smaller the particle size is, the higher is the conversion rate. The gasification reactivity of semi-chars increases with pyrolysis temperature and reaches its maximum at approximately 400°C. The straw semi-char obtained in an H2 pyrolysis atmosphere has the best gasification reactivity, while the semi-char obtained in a CO2 atmosphere has the worst reactivity. In addition, characteristics of semi-char were systematically tested. A random pore model, unreacted core shrinking model and integrated model were employed to describe the reactive behavior of semi-chars. Gasification kinetics parameters were calculated. The random pore model fitting result is in better agreement with the experiments than that of the other two models. PMID:26890792

  6. Combustion of char from plastic wastes pyrolysis

    Science.gov (United States)

    Saptoadi, Harwin; Rohmat, Tri Agung; Sutoyo

    2016-06-01

    A popular method to recycle plastic wastes is pyrolysis, where oil, gas and char can be produced. These products can be utilized as fuels because they are basically hydrocarbons. The research investigates char properties, including their performance as fuel briquettes. There are 13 char samples from PE (Polyethylene) pyrolyzed at temperatures of around 450 °C, with and without a catalyst. Some of the samples were obtained from PE mixed with other types, such as Polystyrene (PS), Polypropylene (PP), Polyethylene Terephthalate (PET), and Others. Char properties, such as moisture, ash, volatile matter, and fixed carbon contents, are revealed from the proximate analysis, whereas calorific values were measured with a bomb calorimeter. Briquettes are made by mixing 4 g of char with 0.5 - 1 g binder. Briquettes are hollow cylinders with an outer and inner diameter of around 1.75 cm and 0.25 cm, respectively. Combustion is carried out in a furnace with wall temperatures of about 230°C and a constant air velocity of 0.7 m/s. Five out of 13 char briquettes are not feasible because they melt during combustion. Briquettes made from 100% PE wastes burn in substantially shorter duration than those from mixed plastic wastes. Char #1 and #5 are excellent due to their highest energy release, whereas #10 show the worst performance.

  7. Life Cycle Assessment of Biochar - EuroChar Project

    Science.gov (United States)

    Rack, M.; Woods, J.

    2012-04-01

    One of the most significant challenges faced by modern-day society is that of global warming. An exclusive focus on reducing the greenhouse gas (GHG) emissions will not suffice and therefore technologies capable of removing CO2 directly from the atmosphere at low or minimal cost are gaining increased attention. The production and use of biochar is an example of such an emerging mitigation strategy. However, as with any novel product, process and technology it is vital to conduct an assessment of the entire life cycle in order to determine the environmental impacts of the new concept in addition to analysing the other sustainability criteria. Life Cycle Assessment (LCA), standardized by ISO (2006a), is an example of a tool used to calculate the environmental impacts of a product or process. Imperial College London will follow the guidelines and recommendations of the ISO 14040 series (ISO 2002, ISO 2006a-b) and the International Life Cycle Data System (ILCD) Handbook (EC JRC IES, 2010a-e), and will use the SimaPro software to conduct a LCA of the biochar supply chains for the EuroChar project. EuroChar ('biochar for Carbon sequestration and large-scale removal of GHG from the atmosphere') is a project funded by the European Commission under its Seventh Framework Programme (FP7). EuroChar aims to investigate and reduce uncertainties around the impacts of, and opportunities for, biochar and, in particular, explore a possible introduction into modern agricultural systems in Europe, thereby moving closer to the determination of the true potential of biochar. EuroChar will use various feedstocks, ranging from wheat straw to olive residues and poplar, as feedstocks for biochar production and will focus on two conversion technologies, Hydrothermal Carbonization (HTC) and Thermochemical Carbonization (TC), followed by the application of the biochar in crop-growth field trials in England, France and Italy. In April 2012, the EuroChar project will be at its halfway mark and

  8. Effects of Processing Parameters on the Forming Quality of C-Shaped Thermosetting Composite Laminates in Hot Diaphragm Forming Process

    Science.gov (United States)

    Bian, X. X.; Gu, Y. Z.; Sun, J.; Li, M.; Liu, W. P.; Zhang, Z. G.

    2013-10-01

    In this study, the effects of processing temperature and vacuum applying rate on the forming quality of C-shaped carbon fiber reinforced epoxy resin matrix composite laminates during hot diaphragm forming process were investigated. C-shaped prepreg preforms were produced using a home-made hot diaphragm forming equipment. The thickness variations of the preforms and the manufacturing defects after diaphragm forming process, including fiber wrinkling and voids, were evaluated to understand the forming mechanism. Furthermore, both interlaminar slipping friction and compaction behavior of the prepreg stacks were experimentally analyzed for showing the importance of the processing parameters. In addition, autoclave processing was used to cure the C-shaped preforms to investigate the changes of the defects before and after cure process. The results show that the C-shaped prepreg preforms with good forming quality can be achieved through increasing processing temperature and reducing vacuum applying rate, which obviously promote prepreg interlaminar slipping process. The process temperature and forming rate in hot diaphragm forming process strongly influence prepreg interply frictional force, and the maximum interlaminar frictional force can be taken as a key parameter for processing parameter optimization. Autoclave process is effective in eliminating voids in the preforms and can alleviate fiber wrinkles to a certain extent.

  9. Investigation of the Anisotropic Behavior of Wood Char Particles during Gasification

    DEFF Research Database (Denmark)

    Henriksen, Ulrik Birk; Hindsgaul, Claus; Qvale, Einar Bjørn;

    2006-01-01

    Wood is a strongly anisotropic material, and likewise, the char produced by pyrolysis of wood is characterized by a strong anisotropy. This anisotropic behavior allows relatively easy transport of gas in the longitudinal (L) direction of the wood, but the transport is much less easy in the radial...... during gasification of wood using macro TGA equipment. The char particles, in the form of slabs (approximately 50 × 70 × 10 mm), were produced by pyrolysis of wood slabs that had been cut from the trunk of beech trees. The char slabs were grouped into three categories according to the orientation...... of the normal to the greater surface of the slabs L, R, or T (see Figure 8). When the smaller surfaces were coated with alumina silicate, the gasification agent could only enter the interior of the slabs through the greater surfaces. Thermally thick char particles from beech and pine reacted more slowly...

  10. Effect of surface area and chemisorbed oxygen on the SO2 adsorption capacity of activated char

    Science.gov (United States)

    Lizzio, A.A.; DeBarr, J.A.

    1996-01-01

    The objective of this study was to determine whether activated char produced from Illinois coal could be used effectively to remove sulfur dioxide from coal combustion flue gas. Chars were prepared from a high-volatile Illinois bituminous coal under a wide range of pyrolysis and activation conditions. A novel char preparation technique was developed to prepare chars with SO2 adsorption capacities significantly greater than that of a commercial activated carbon. In general, there was no correlation between SO2 adsorption capacity and surface area. Temperature-programmed desorption (TPD) was used to determine the nature and extent of carbon-oxygen (C-O) complexes formed on the char surface. TPD data revealed that SO2 adsorption was inversely proportional to the amount of C-O complex. The formation of a stable C-O complex during char preparation may have served only to occupy carbon sites that were otherwise reactive towards SO2 adsorption. A fleeting C(O) complex formed during SO2 adsorption is postulated to be the reaction intermediate necessary for conversion of SO2 to H2SO4. Copyright ?? 1996 Elsevier Science Ltd.

  11. Influence of Pyrolysis Temperature on Rice Husk Char Characteristics and Its Tar Adsorption Capability

    OpenAIRE

    Anchan Paethanom; Kunio Yoshikawa

    2012-01-01

    A biomass waste, rice husk, was inspected by thermoanalytical investigation to evaluate its capability as an adsorbent medium for tar removal. The pyrolysis process has been applied to the rice husk material at different temperatures 600, 800 and 1000 °C with 20 °C/min heating rate, to investigate two topics: (1) influence of temperature on characterization of rice husk char and; (2) adsorption capability of rice husk char for tar removal. The results showed that subsequent ...

  12. Techno-Economic Assessment of Pyrolysis Char Production and Application – A Review

    OpenAIRE

    KUPPENS, Tom; VAN DAEL, Miet; Vanreppelen, Kenny; Carleer, Robert; Yperman, Jan; SCHREURS, Sonja; Van Passel, Steven

    2014-01-01

    Many organic residue streams such as pig manure are not or inefficiently used, although they can be converted into valuable materials, as well as energy, using pyrolysis. The yield of the pyrolysis products (i.e. oil, gas and char) is dependent on the process conditions and the feedstock used. Char as a soil amendment or activated carbon are interesting options for valorization of biomass residues. Here, a review is presented of the techno-economic potential of both valorization options based...

  13. Spring-back of flexible roll forming bending process

    Science.gov (United States)

    Zhang, Y.; Kim, D. H.; Jung, D. W.

    2015-12-01

    Simulations are now widely used in the field of roll forming because of their convenience. Simulations provide a low cost, secure and fast analysis tool. Flexible roll forming provides the desired shapes with a one time forming process. For roll forming, the velocity of the sheet and friction are important factors to attain an ideal shape. Because it is a complicated process, simulations provide a better understanding of the roll forming process. Simulations were peformed using ABAQUS software linked to elastic-plastic modules which we developed taking into account of interactions between these fields [1]. The application of this method makes it possible to highlight the strain-stress and mechanical behaviour laws and the spring-back. Thus, the flexible roll forming and bending process can bewell described by the simulation software and guide the actual machine.

  14. Pyrolysis of flax straw: Characterization of char, liquid, and gas as fuel

    Science.gov (United States)

    Tushar, Mohammad Shahed Hasan Khan

    The demand for energy continues to outstrip its supply and necessitates the development of renewable energy options. Biomass has been recognized as a major renewable energy source to supplement the declining fossil fuel source of energy. It is the most popular form of renewable energy and, currently, biofuel production is becoming more promising. Being carbon neutral, readily available, and low in sulphur content makes biomass a very promising source of renewable energy. In the present research, both the isothermal and non-isothermal pressurized pyrolysis of flax straw is studied for the first time. In case of isothermal pyrolysis, the influence of pyrolysis temperature and reaction time on char yield and morphology was investigated. The applied pyrolysis temperature was varied between 300 and 500°C. The reaction time was varied from 15 to 60 min. The char yield was found to decrease as pyrolysis temperature and reaction time increased. The char structure and surface morphology were thoroughly investigated by means of x-ray diffraction (XRD), temperature-programmed oxidation (TPO), and scanning electron microscopy (SEM). The degree of porosity and graphitization increased as pyrolysis temperature and time increased. In fact, the experiment performed at 500°C for 1h duration did not yield any char; only residual ash could be obtained. The TPO studies on the char samples corroborated the XRD findings and showed the presence of two types of carbon, namely, amorphous filamentous carbon and graphitic carbon. A thermogravimetric analysis (TGA) of the char was performed to gain an understanding of combustion kinetics and reactivity. It implied that the reactivity of the char decreases as temperature increases, and this finding is well supported by the TPO, TGA, SEM, and XRD characterization data. Furthermore, an empirical global model was devised based on the power law to estimate activation energy and other kinetic parameters. For the non-isothermal pressurized

  15. Modeling pyrolysis of charring material in fire

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A modified model of pyrolysis for charring materials in fire has been proposed in this note. In this model some special factors which show the effect on pyrolysis are considered, i.e. heat loss by convection and radiation caused by surface temperature rise and shrinkage of char surface are considered. Experimental device is designed specially for validating the reliability of the model. Effects of density of materials and heat radiation on pyrolysis of materials have also been investigated.

  16. Effect of burn-off on physical and chemical properties of coal char; Gas ka shinko ni tomonau sekitan char no tokusei henka

    Energy Technology Data Exchange (ETDEWEB)

    Yamada, T.; Tamura, K.; Hashimoto, H.; Funaki, M.; Suzuki, T. [Kitami Institute of Technology, Hokkaido (Japan)

    1996-10-28

    For high-efficiency coal gasification, investigations were given on effect of coal chars with different conversion rates on coal gasification reactivity. In coal gasification, reactivity of char after pyrolysis governs the efficiency. The reference char conversion in CO2 gasification of coal (weight loss) changes linearly in the initial stage of the reaction, but the reactivity declines as the end point is approached. Char surface area is as large as 400 m{sup 2}/g in the initial stage with the conversion at 20%, but it decreases in the final stage. This phenomenon relates closely with changes in pore size and crystalline structure. Change in the Raman value R which shows incompleteness of char graphite structure and amorphous carbon ratio suggests that an active portion with high reactivity is oxidized preferentially, and a portion with low reactivity remains finally. Minerals in coal are known to accelerate the gasification. However, their catalytic effect is related with chemical forms, and complex as they may change into inactive sulfides and silicates under severe reaction conditions. Change in forms of calcium compounds may also be involved in decline of the reactivity in the latter stage. 8 refs., 4 figs.

  17. Reactivity of young chars via energetic distribution measurements. Final report, 1 September 1990--31 December 1994

    Energy Technology Data Exchange (ETDEWEB)

    Calo, J.M.; Zhang, L.; Lu, W.; Lilly, W.D.

    1996-01-01

    We have developed what we believe to be the very first, a priori, correlation/prediction technique for the gasification reactivity of coal char. With this method the gasification reactivity of a coal char as a function of temperature can be correlated using the data from a temperature programmed desorption (TPD) experiment following gasification under conditions where the reactivity is controlled by the thermal desorption of oxygen surface complexes formed during gasification. The current project was directed at extending and developing related techniques for the characterization and prediction/correlation of the reactivity of the ``young`` chars to CO{sub 2} and steam. Of particular interest was mapping of the reactivity behavior of the resultant chars, as revealed by the energetic heterogeneity of the complexes with char preparation conditions.

  18. Effect of processing parameters on bulge-forming Polycarbonate parts

    Institute of Scientific and Technical Information of China (English)

    HOU Zhen-xiu; WU Jing; LIU Zhi; LI Xiao-dong; Z. R. Wang

    2007-01-01

    According to the data of the experiment made in mechauical tensile of Polycarbonate in high temperature, experiments were done to polycarbonate sheet by hot gas pressure bulge-forming. It was found that selecting and combination of the processing parameters were vital to the quality. In the experiments and numerical simulation with the software of DYNAFORM, the processing parameters have been studied. The results showed that the method of discontinuous pressure and pressure preservation advantage the forming; when temperature and pressure meet the forming conditions, the longer time of pressure preservation promotes sufficient forming.

  19. ENHANCING ASPHALT RHEOLOGICAL BEHAVIOR AND AGING SUSCEPTIBILITY USING BIO-CHAR AND NANO-CLAY

    Directory of Open Access Journals (Sweden)

    Renaldo C. Walters

    2014-01-01

    Full Text Available The life expectancy of Asphalt Binder (AB has been negatively impacted by the harsh bombardment of UV rays. UV rays cause asphalt to oxidize faster, which results in deterioration of asphalt rheological characteristics that can lead to pavement distresses. This study investigates the impact of bio-char and nano-clay of asphalt rheological properties. Two nano scale materials were used for this study were nano-clay and bio-char. Nano-clay (Cloisite 30B is a naturally occurring inorganic mineral. Bio-char is the waste product from bio-binder production. Bio-binder is produced from swine manure using a thermochemical conversion process. This process is then followed by a filtration procedure where the bio-char is produced. Chemical and physical properties of bio-char showed a significant presence of carbon which could in turn enhance asphalt flow properties and reduce the rate of asphalt oxidation. In this study several mixtures are designed and evaluated using Rotational Viscometer testing (RV and X-Ray Diffraction (XRD. Nano-clay is blended at 2 and 4% by weight, with and without bio-binder (5% by weight of dry mass. Bio-char is grinded to nano scale and added to the virgin asphalt binder (PG 64-22 at 2, 5 and 10% by weight. The study results showed that introduction of nano-clay could be effective in reducing temperature susceptibility of asphalt binder.

  20. Changes in char reactivity due to char-oxygen and char-steam reactions using Victorian brown coal in a fixed-bed reactor

    Institute of Scientific and Technical Information of China (English)

    Shu Zhang; Yonggang Luo; Chunzhu Li; Yonggang Wang

    2015-01-01

    This study was to examine the influence of reactions of char–O2 and char–steam on the char reactivity evolution. A newly-designed fixed-bed reactor was used to conduct gasification experiments using Victorian brown coal at 800 °C. The chars prepared from the gasification experiments were then collected and subjected to reactivity characterisation (ex-situ reactivity) using TGA (thermogravimetric analyser) in air. The results indicate that the char reactivity from TGA was generally high when the char experienced intensive gasification reactions in 0.3%O2 in the fixed-bed reactor. The addition of steam into the gasification not only enhanced the char conversion sig-nificantly but also reduced the char reactivity dramatical y. The curve shapes of the char reactivity with involve-ment of steam were very different from that with O2 gasification, implying the importance of gasifying agents to char properties.

  1. A Study on Forming Characteristics of Roll Forming Process with High Strength Steel

    Science.gov (United States)

    Joo, ByeongDon; Lee, HyunJong; Kim, DongKyu; Moon, YoungHoon

    2011-08-01

    Roll forming is a kind of sheet metal forming process used to manufacture long sheet metal products with constant cross section. Recently, roll forming technology draws attentions of automotive industries due to its various advantages, such as high production speed, reduced tooling cost and improved quality. In automotive industries, roll formed automotive parts used as structural components in vehicle body frame or sub frame and high strength steel becomes more common to improve safety and fuel efficiency. However, when roll forming process is performed with high strength steel, rolling forming defects, such as spring back, buckling and scratch should be considered more carefully. In this study, efforts to avoid roll forming defects and to optimize forming parameters were performed. FE analysis was performed with high strength steels using commercially available simulation software, COPRA-RF™ and SHAPE-RF™. Forming characteristics were analyzed and roll flower model and proper roll-pass sequences were suggested by analyzing longitudinal strain and deformation behavior. This study provided considerable experience about roll forming process design that using high strength steel.

  2. Char characterisation and its application in a coal burnout mode

    Energy Technology Data Exchange (ETDEWEB)

    Michael Cloke; Tao Wu; Richelieu Barranco; Ed Lester [University of Nottingham, Nottingham (United Kingdom). Nottingham Fuel and Energy Centre, School of Chemical, Environmental and Mining Engineering, Coal Technology Research Group

    2003-10-01

    In this study, char image analysis techniques have been employed to investigate the morphology of chars obtained from a Drop-Tube furnace. Char image analysis results have been incorporated as inputs to a char burnout model based on Hurt's CBK model. It has been observed that the char combustion rate was strongly affected by char structural parameters and the inclusion of char morphology has led to a better prediction of char burnout. It has also been suggested by the model that the inclusion of ash inhibition overestimates the resistance attributed by ash film and the consideration of ash film resistance should be undertaken in a different way to give a better prediction at the later stages of char combustion. 12 refs., 13 figs., 5 tabs.

  3. A Plasticity Induced Anisotropic Damage Model for Sheet Forming Processes

    NARCIS (Netherlands)

    Niazi, M.S.; Meinders, V.T.; Wisselink, H.H.; Horn, ten C.H.L.J.; Klaseboer, G.; Boogaard, van den A.H.

    2013-01-01

    Plastic deformation induces damage in Advanced High Strength Steels (AHSS). Therefore damage development in these steels shall be studied and incorporated in the simulations for accurate failure predictions in forming processes and for determination of the product properties after forming. An effici

  4. FE analysis of tube forming process with experimental verification

    OpenAIRE

    Mandic, V.; Stefanovic, M.; M. Zivkovic; N. Grujovic; B. Misic

    2006-01-01

    Purpose: of this paper: The paper presents some results of extensive investigation of steel seam-welded tubesforming process, by applying combined treatment of material narrowing and expansion. The objective ofexecuted numerical FE and experimental investigations was to determine the optimal technology for productionof tubular product at simple tools and at the standard forming processing machines, without defects and withdemanded dimensional accuracy.Design/methodology/approach: Tube forming...

  5. Polymer blends formed by the solid state mechanical alloying process

    OpenAIRE

    Farrell, Michael P.

    1994-01-01

    In the early 1970's a new processing technique to produce metallic alloys was developed by Benjamin and co-workers. This novel technique, called Mechanical Alloying (MA), involves the repeated welding, working hardening, and fracture of metallic powders to form an alloy. The research presented in this thesis describes the use of the MA process to form polymer blends. Until recently there has been no published work discussing the possibility of using this technique with polymers...

  6. Comparative assessment of TRU waste forms and processes. Volume II. Waste form data, process descriptions, and costs

    International Nuclear Information System (INIS)

    This volume contains supporting information for the comparative assessment of the transuranic waste forms and processes summarized in Volume I. Detailed data on the characterization of the waste forms selected for the assessment, process descriptions, and cost information are provided. The purpose of this volume is to provide additional information that may be useful when using the data in Volume I and to provide greater detail on particular waste forms and processes. Volume II is divided into two sections and two appendixes. The first section provides information on the preparation of the waste form specimens used in this study and additional characterization data in support of that in Volume I. The second section includes detailed process descriptions for the eight processes evaluated. Appendix A lists the results of MCC-1 leach test and Appendix B lists additional cost data. 56 figures, 12 tables

  7. Characterization and biodegradation of water-soluble biomarkers and organic carbon extracted from low temperature chars

    Energy Technology Data Exchange (ETDEWEB)

    Norwood, Matt J.; Louchouarn, Patrick; Kuo, Li-Jung; Harvey, Omar

    2013-03-16

    This study demonstrates that wildfires/biomass combustion may be an important source of labile pyrogenic water-soluble organic matter (Py-WSOM) to aquatic systems. Spectroscopic analysis (of the solid char and Py-WSOM) with Fourier transform infrared spectroscopy (FTIR) indicated that the Py-WSOM extracted from two low temperature chars (one wood, one grass) was dominated by polar moieties (-OH and C-O) derived from depolymerization and fragmentation of lignocellulose. Incubation experiments under aerobic conditions with unsterilized river water suggested that Py-WSOM and associated biomarkers may have turnover rates on the order of weeks to months, consistent with mixing and transport conditions of riverine systems. For example, pyrogenic dissolved organic carbon (Py-DOC) had a half-life of 30-40 days. Turnover rate for the combustion biomarkers was shorter, with levoglucosan and free lignin phenols having a half-life around 3-4 days and polymeric lignin components 13-14 days. The latter observations contradict earlier studies on the biodegradation of dissolved lignin and point to the need for re-assessment of lignin degradation kinetics in well-mixed riverine systems, particularly when such lignin components are derived from thermally altered plant material that may exist in a form more labile than that in highly processed riverine DOM.

  8. Characterization of chars produced in the co-pyrolysis of different wastes: decontamination study.

    Science.gov (United States)

    Bernardo, M; Gonçalves, M; Lapa, N; Barbosa, R; Mendes, B; Pinto, F

    2012-03-15

    The present work is devoted to the study of the decontamination of chars obtained in the co-pyrolysis of plastics, biomass and tyre wastes. The chars were extracted with several organic solvents of different polarities either individually or in sequence. The ability of each selected extractant to remove toxic pollutants was evaluated by comparing the extraction yields and by characterizing the crude extracts with a combination of chemical analysis and toxicity bioassays. Also, the mineral composition of the treated and non-treated chars was assessed. The results obtained in this study indicate that hexane is the more efficient extraction solvent to be used in the organic decontamination of chars obtained in the co-pyrolysis of plastics, tyres and biomass. A sequential extraction with solvents of increasing polarity can provide a better decontamination of the raw pyrolysis char than any individual extraction. The compounds removed from the char during the decontamination process are mainly aliphatic hydrocarbons and aromatic hydrocarbons, therefore a material that may be upgraded to be used as a fuel and/or as raw material for the organic chemical industry. PMID:21899951

  9. The potential applications of using compost chars for removing the hydrophobic herbicide atrazine from solution

    Science.gov (United States)

    Tsui, L.; Roy, W.R.

    2008-01-01

    One commercial compost sample was pyrolyzed to produce chars as a sorbent for removing the herbicide atrazine from solution. The sorption behavior of compost-based char was compared with that of an activated carbon derived from corn stillage. When compost was pyrolyzed, the char yield was greater than 45% when heated under air, and 52% when heated under N2. In contrast, when the corn stillage was pyrolyzed under N2, the yield was only 22%. The N2-BET surface area of corn stillage activated carbon was 439 m2/g, which was much greater than the maximum compost char surface area of 72 m2/g. However, the sorption affinity of the compost char for dissolved atrazine was comparable to that of the corn stillage activated carbon. This similarity could have resulted from the initial organic waste being subjected to a relatively long period of thermal processes during composting, and thus, the compost was more thermally stable when compared with the raw materials. In addition, microorganisms transformed the organic wastes into amorphous humic substances, and thus, it was likely that the microporisity was enhanced. Although this micropore structure could not be detected by the N2-BET method, it was apparent in the atrazine sorption experiment. Overall, the experimental results suggested that the compost sample in current study was a relatively stable material thermally for producing char, and that it has the potential as a feed stock for making high-quality activated carbon. ?? 2007 Elsevier Ltd. All rights reserved.

  10. INDUSTRIAL PROCESS VALIDATION OF TABLET DOSAGE FORM: AN OVERVIEW

    Directory of Open Access Journals (Sweden)

    Gupta Surbhi

    2012-03-01

    Full Text Available In pharmaceutical organizations, validation is a fundamental segment that supports a company commitment to quality assurance. Validation is a tool of quality assurance which provides confirmation of the quality in equipment systems, manufacturing processes, software and testing methods. Validation assures that products with pre-determined quality characteristics and attributes can be reproduced consistently/reproducibly within the established limits of the manufacturing process operation at the manufacturing site. Validation of the individual steps of the manufacturing processes is called the process validation. Different dosage forms have different validation protocols. Here this article concentrates on the process validation of tablet dosage form, protocol preparation and regulatory basis for process validation in industry. It gives in detail the validation of each step of the manufacturing process of tablets through wet granulation.

  11. From Function to Context to Form: Precedents and Focus Shifts in the Form Creation Process

    DEFF Research Database (Denmark)

    Restrepo-Giraldo, John Dairo

    2005-01-01

    In design, the form creation process involves imagining, seeing and drawing. Translating the vague and imprecise initial ideas into sketches requires significant ability, and in this process, images of existing products (precedents) are a welcomed aid. Searching for them, however, is difficult, b...

  12. SET OF CRITERIA FOR EFFICIENCY OF THE PROCESS FORMING SET OF CRITERIA FOR EFFICIENCY OF THE PROCESS FORMING

    Directory of Open Access Journals (Sweden)

    Alexander Aleksandrovich RYBANOV,

    Full Text Available Is offered the set of criteria for assessing efficiency of the process forming the answers to multiple-choice test items. To increase accuracy of computer-assisted testing results, it is suggested to assess dynamics of the process of forming the final answer using the following factors: loss of time factor and correct choice factor. The model application results show the high efficiency of suggested set of criterias

  13. From Steady-State To Cyclic Metal Forming Processes

    Science.gov (United States)

    Montmitonnet, Pierre

    2007-05-01

    Continuous processes often exhibit a high proportion of steady state, and have been modeled with steady-state formulations for thirty years, resulting in very CPU-time efficient computations. On the other hand, incremental forming processes generally remain a challenge for FEM software, because of the local nature of deformation compared with the size of the part to be formed, and of the large number of deformation steps needed. Among them however, certain semi-continuous metal forming processes can be characterized as periodic, or cyclic. In this case, an efficient computational strategy can be derived from the ideas behind the steady-state models. This will be illustrated with the example of pilgering, a seamless tube cold rolling process.

  14. INDUSTRIAL PROCESS VALIDATION OF SOLID ORAL DASAGE FORM: A REVIEW

    OpenAIRE

    Vishal Sharma; A C Rana; Nimrata Seth

    2013-01-01

    Validation is the important step in gaining and maintaining the quality of the final product. Validation of the individual steps of the processes is called the process validation. Different dosage forms have different validation protocols. Validation is therefore is one element of quality assurance programs and is associated with a particular process therefore word validation simply means “assessment of validity” or action of proving effectiveness. Validation thus provides a higher degree of ...

  15. Effective Diffusion Coefficients in Coal Chars

    DEFF Research Database (Denmark)

    Johnsson, Jan Erik; Jensen, Anker

    2001-01-01

    Knowledge of effective diffusion coefficients in char particles is important when interpreting experimental reactivity measurements and modeling char combustion or NO and N2O reduction. In this work, NO and N2O reaction with a bituminous coal char was studied in a fixed-bed quartz glass reactor....... Particle sizes in the range 0.05-5 mm were tested, and the effective diffusion coefficients were estimated from measured effectiveness factors using the Thiele modulus. At 1079 K the effective diffusion coefficients were 5.5 X 10(-6) m(2)/s and 6.8 X 10(-6) m(2)/s for N2O and NO, respectively....... The experimental results were compared with theoretical values calculated from the mean pore radius and the cross-linked pore model. The method of mean pore radius underestimated the effective diffusion coefficient more than an order of magnitude. Using the cross-linked pore model, the bimodal pore size...

  16. Evaluation of char combustion models: measurement and analysis of variability in char particle size and density

    Energy Technology Data Exchange (ETDEWEB)

    Daniel J. Maloney; Esmail R. Monazam; Kent H. Casleton; Christopher R. Shaddix

    2008-08-01

    Char samples representing a range of combustion conditions and extents of burnout were obtained from a well-characterized laminar flow combustion experiment. Individual particles from the parent coal and char samples were characterized to determine distributions in particle volume, mass, and density at different extent of burnout. The data were then compared with predictions from a comprehensive char combustion model referred to as the char burnout kinetics model (CBK). The data clearly reflect the particle- to-particle heterogeneity of the parent coal and show a significant broadening in the size and density distributions of the chars resulting from both devolatilization and combustion. Data for chars prepared in a lower oxygen content environment (6% oxygen by vol.) are consistent with zone II type combustion behavior where most of the combustion is occurring near the particle surface. At higher oxygen contents (12% by vol.), the data show indications of more burning occurring in the particle interior. The CBK model does a good job of predicting the general nature of the development of size and density distributions during burning but the input distribution of particle size and density is critical to obtaining good predictions. A significant reduction in particle size was observed to occur as a result of devolatilization. For comprehensive combustion models to provide accurate predictions, this size reduction phenomenon needs to be included in devolatilization models so that representative char distributions are carried through the calculations.

  17. Process designing for laser forming of circular sheet metal

    Institute of Scientific and Technical Information of China (English)

    Q. Nadeem; W. J. Seong; S. J. Na

    2012-01-01

    Laser forming is a new type of flexible manufacturing process that has become viable for the shaping of metallic components.Process designing of laser forming involves finding a set of process parameters,including laser power,laser scanning paths,and scanning speed,given a prescribed shape.To date,research has focused on process designing for rectangular plates,and only a few studies are presented for axis-symmetric geometries like circular plates.In the present study,process designing for axis-symmetric geometries-with focus on class of shapes--is handled using a formerly proposed distance-based approach.A prescribed shape is achieved for geometries such as quarter-circular and half-circular ring plates.Experimental results verify the applicability of the proposed method for a class of shapes.%Laser forming is a new type of flexible manufacturing process that has become viable for the shaping of metallic components. Process designing of laser forming involves finding a set of process parameters, including laser power, laser scanning paths, and scanning speed, given a prescribed shape. To date, research has focused on process designing for rectangular plates, and only a few studies are presented for axis-symmetric geometries like circular plates. In the present study, process designing for axis-symmetric geometries-with focus on class of shapes-is handled using a formerly proposed distance-based approach. A prescribed shape is achieved for geometries such as quarter-circular and half-circular ring plates. Experimental results verify the applicability of the proposed method for a class of shapes.

  18. A method for setting variables in Super Plastic Forming process

    Directory of Open Access Journals (Sweden)

    N. Cappetti

    2010-02-01

    Full Text Available Purpose: Superplastic forming (SPF technology exceeds the limit of standard presswork either of form or of thickness distribution, but the lead time and the energy expenditure are more onerous for industrial use. The aim of this work is to study the role that process parameters play in a superplastic forming manufacturing in order to minimize the processing times and the cost respecting the “total quality” of the finished product.Design/methodology/approach: Identified the basic parameters of SPF process that is the thickness of blank, the strain rate and the processing temperature, were chosen three different values for each of them. For each combination of parameters and using finite element software, a forming simulation of a sample part was made. Important parameters as thickness reduction, stress distribution, time/working pressure curve are calculated and evaluated.Findings: The obtained results were manipulated in order to create some global indicators that was analysed to study the reliance on process quality and production costs.Research limitations/implications: The other and more difficult to define parameters, such as cast and initial sheet shape, friction between cast and sheet, need to be evacuated because they also affect the optimisation process, as well as its affordability, that is the result of careful control of process variables.Practical implications: The highlighted dependencies are whatever useful, during process configuration, to drive production choices for quality improvement and cost reduction of superplastic formed components.Originality/value: The interesting result is that some dependencies are not as strong as expected from literature. As an example, the quality parameters dependence on the strain rate is no linear. So much as to the decrease of strain rate some indices worsen considerably.

  19. Failure mechanism and forming limit of tube axial compressive process

    Institute of Scientific and Technical Information of China (English)

    SUN Zhi-chao; YANG He

    2006-01-01

    Based on minimum energy principle for plastic forming,tearing and buckling failures mechanisms are explored and criteria for them are developed by theoretical analysis and experiment. Combined with finite element software developed forming limit and effects of process parameters on failures are investigated and proper parameters for stable forming are determined. The results show that: 1) The failures and forming limit are mainly determined by geometry and materials parameters of tube blank,fillet radius or half conical angle of die. For the process under fillet die,there exists a maximum fillet radius within which no tearing failure happens,and a maximum radius and a minimum radius range within which no buckling failure happens. For the process under conical die,there exists a maximum and minimum half conical angle range within which no tearing and buckling failures occur. 2) For both forming processes,the higher the value of material strain hardening exponent or the lower the value of relative thickness,the more impossible for tearing and buckling failures to occur,and the larger the ranges of fillet radius and half conical angle. The experiment results verify the reliability and practicability of this research.

  20. QuikForm: Intelligent deformation processing of structural alloys

    Energy Technology Data Exchange (ETDEWEB)

    Bourcier, R.J.; Wellman, G.W.

    1994-09-01

    There currently exists a critical need for tools to enhance the industrial competitiveness and agility of US industries involved in deformation processing of structural alloys. In response to this need, Sandia National Laboratories has embarked upon the QuikForm Initiative. The goal of this program is the development of computer-based tools to facilitate the design of deformation processing operations. The authors are currently focusing their efforts on the definition/development of a comprehensive system for the design of sheet metal stamping operations. The overall structure of the proposed QuikForm system is presented, and the focus of their thrust in each technical area is discussed.

  1. Synthesis of palm oil empty fruit bunch magnetic pyrolytic char impregnating with FeCl3 by microwave heating technique

    International Nuclear Information System (INIS)

    Empty fruit bunch (EFB) is one of the most abundant residues of the Palm oil mill industry in Malaysia. The novel magnetic bio-char was synthesized by single stage microwave heating technique, using EFB in the presence of ferric chloride hexahydrate. The effect of microwave powers, radiation time and impregnation ratio (IR) of ferric chloride hexahydrate to biomass were studied. Also the process parameters such as microwave powers, radiation times and IR were optimized using response surface method. The statistical analysis revealed that the optimum conditions for the high porosity magnetic bio-char production were at 900 W microwave power, 20 min radiation time and 0.5 (FeCl3: biomass) impregnation ratio. These newly produced magnetic bio-char have a high surface area of 890 m2 g−1 and that leads to highly efficient in the removal of methylene blue (MB) with an efficiency of 99.9% from aqueous solution with a maximum adsorption capacity of 265 mg g−1. - Highlights: • Magnetic bio-char production using discarded material EFB with chemical activation. • Single stage synthesis of magnetic bioc-har via microwave heating was narrated. • Effect of each process parameters on synthesis of magnetic bio-char was elaborated. • Magnetic bio-char has high surface area, high porosity and high adsorption capacity. • Novel magnetic bio-char adds new dimension to the materials as an adsorbent

  2. Melt processed multiphase ceramic waste forms for nuclear waste immobilization

    Energy Technology Data Exchange (ETDEWEB)

    Amoroso, Jake, E-mail: jake.amoroso@srs.gov [Savannah River National Laboratory, Aiken, SC 29808 (United States); Marra, James C. [Savannah River National Laboratory, Aiken, SC 29808 (United States); Tang, Ming [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Lin, Ye; Chen, Fanglin [University of South Carolina, Columbia, SC 29208 (United States); Su, Dong [Brookhaven National Laboratory, Upton, NY 11973 (United States); Brinkman, Kyle S. [Clemson University, Clemson, SC 29634 (United States)

    2014-11-15

    Highlights: • We explored the feasibility of melt processing multiphase titanate-based ceramics. • Melt processing produced phases obtained by alternative processing methods. • Phases incorporated multiple lanthanides and transition metals. • Processing in reducing atmosphere suppressed un-desirable Cs–Mo coupling. • Cr partitions to and stabilizes the hollandite phase, which promotes Cs retention. - Abstract: Ceramic waste forms are promising hosts for nuclear waste immobilization as they have the potential for increased durability and waste loading compared with conventional borosilicate glass waste forms. Ceramics are generally processed using hot pressing, spark plasma sintering, and conventional solid-state reaction, however such methods can be prohibitively expensive or impractical at production scales. Recently, melt processing has been investigated as an alternative to solid-state sintering methods. Given that melter technology is currently in use for High Level Waste (HLW) vitrification in several countries, the technology readiness of melt processing appears to be advantageous over sintering methods. This work reports the development of candidate multi-phase ceramic compositions processed from a melt. Cr additions, developed to promote the formation and stability of a Cs containing hollandite phase were successfully incorporated into melt processed multi-phase ceramics. Control of the reduction–oxidation (Redox) conditions suppressed undesirable Cs–Mo containing phases, and additions of Al and Fe reduced the melting temperature.

  3. Particle behavior and char burnout mechanisms under pressurized combustion conditions

    Energy Technology Data Exchange (ETDEWEB)

    Bauer, C.M.; Spliethoff, H.; Hein, K.R.G.

    1999-07-01

    Combined cycle systems with coal-fired gas turbines promise highest cycle efficiencies for this fuel. Pressurized pulverized coal combustion, in particular, yields high cycle efficiencies due to the high flue gas temperatures possible. The main problem, however, is to ensure a flue gas clean enough to meet the high gas turbine standards with a dirty fuel like coal. On the one hand, a profound knowledge of the basic chemical and physical processes during fuel conversion under elevated pressures is required whereas on the other hand suitable hot gas cleaning systems need to be developed. The objective of this work was to provide experimental data to enable a detailed description of pressurized coal combustion processes. A series of experiments were performed with two German hvb coals, Ensdorf and Goettelborn, and one German brown coal, Garzweiler, using a semi-technical scale pressurized entrained flow reactor. The parameters varied in the experiments were pressure, gas temperature and bulk gas oxygen concentration. A two-color pyrometer was used for in-situ determination of particle surface temperatures and particle sizes. Flue gas composition was measured and solid residue samples taken and subsequently analyzed. The char burnout reaction rates were determinated varying the parameters pressure, gas temperature and initial oxygen concentration. Variation of residence time was achieved by taking the samples at different points along the reaction zone. The most influential parameters on char burnout reaction rates were found to be oxygen partial pressure and fuel volatile content. With increasing pressure the burn-out reactions are accelerated and are mostly controlled by product desorption and pore diffusion being the limiting processes. The char burnout process is enhanced by a higher fuel volatile content.

  4. Non linear finite element simulation of complex bulge forming processes

    OpenAIRE

    Mac Donald, Bryan J

    2000-01-01

    Bulge forming is a manufacturing process that is becoming increasingly important as a technology that can be used to produce seamless, lightweight and near-net-shape industrial components. The process is being increasingly applied in the automotive and aerospace industries where the demands for increased structural strength and decreased vehicle weight make it a very attractive manufacturing method. This work is concerned with increasing knowledge of the deformation mechanisms during bulg...

  5. The Ceramic Waste Form Process at Idaho National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Stephen Priebe

    2007-05-01

    The treatment of spent nuclear fuel for disposition using an electrometallurgical technique results in two high-level waste forms: a ceramic waste form (CWF) and a metal waste form. Reactive metal fuel constituents, including all the transuranic metals and the majority of the fission products remain in the salt as chlorides and are processed into the CWF. The solidified salt is containerized and transferred to the CWF process where it is ground in an argon atmosphere. Zeolite 4A is ground and then dried in a mechanically-fluidized dryer. The salt and zeolite are mixed in a V-mixer and heated to 500°C to occlude the salt into the structure of the zeolite. The salt-loaded zeolite is cooled, mixed with borosilicate glass frit, and transferred to a crucible, which is placed in a furnace and heated to 925°C. During this process, known as pressureless consolidation, the zeolite is converted to the final sodalite form and the glass thoroughly encapsulates the sodalite, producing a dense, leach-resistant final waste form.

  6. Kinetic Analysis of Char Thermal Deactivation

    DEFF Research Database (Denmark)

    Zolin, Alfredo; Jensen, Anker; Dam-Johansen, Kim

    2001-01-01

    The thermal deactivation of several fuels was investigated by measuring the reactivity, of chars prepared in a thermogravimetric analyzer (TGA) apparatus at well-defined conditions in the temperature range 973-1673 K. Four coals, Blair Athol from Australia, Cerrejon from Colombia. Illinois no. 6...

  7. Phosphorus recovery from sewage sludge char ash

    NARCIS (Netherlands)

    Atienza-Martinez, M.; Gea, G.; Arauzo, J.; Kersten, S.R.A.; Kootstra, A.M.J.

    2014-01-01

    Phosphorus was recovered from the ash obtained after combustion at different temperatures (600 °C, 750 °C and 900 °C) and after gasification (at 820 °C using a mixture of air and steam as fluidising agent) of char from sewage sludge fast pyrolysis carried out at 530 °C. Depending on the leaching con

  8. Multi-Channel Processing for Digital Beam Forming SAR

    NARCIS (Netherlands)

    Otten, M.P.G.; Rossum, W.L. van; Tan, R.; Vlothuizen, W.J.; Wit, J.J.M. de

    2013-01-01

    A lightweight radar system, suitable for use on board small airborne platforms, has been built and tested. The radar system comprises a digital receive array, offering full beam forming flexibility at the cost of high data rates and heavy processing loads. In this paper, the requirements and archite

  9. Influence of process parameters on hybrid forming of aluminum sheet

    Institute of Scientific and Technical Information of China (English)

    张新明; 陈明安

    2001-01-01

    The influences of the plastic melt pressure and its distribution from the gate to the end of the mold, and of the friction coefficient between the sheet flange and the mold on forming process of the aluminum sheet have been investigated by Finite Element Method. It was shown that further deformation is mainly concentrated on metal sheet around the root corner of the mold, and that two highly strained zones with the severest thickness reduction are formed when the plastic melt pressure increased from 30 MPa to 50 MPa. The deformation of the sheet flange decreased and biaxial tension in plane of the sheet in the mold increased with increase of the friction coefficient. The non-uniform distribution of the plastic melt pressure had negligible influence on forming process of the sheet.

  10. Effects of Hybrid Fibre Reinforcement on Fire Resistance Performance and Char Morphology of Intumescent Coating

    Directory of Open Access Journals (Sweden)

    Amir N.

    2016-01-01

    Full Text Available Recent researches of fire retardant intumescent coatings reinforced by single Rockwool and single glass wool fibre at various weight percentages and lengths showed some improvements to the mechanical properties of the coatings and the char produced. Therefore, in this research the fibres were combined together in intumescent coating formulation at several weight percentages and fibre lengths to study their effects towards fire resistance performance and char morphology. The hybrid fibre reinforced intumescent coatings were subjected to two types of fire tests; Bunsen burner at 1000°C and the electric furnace at 800°C for 1 hour, respectively. Steel temperature of the coated samples during Bunsen burner test was recorded to determine the fire resistance performance. Thermal stability of the intumescent coatings and chars was determined by Thermogravimetric Analysis (TGA. The morphology of the coatings and char was then examined by using Scanning Electron Microscopy (SEM and Energy Dispersive Spectrometry (EDS was conducted to obtain elemental composition of the samples. This research concluded that long-hybrid fibre at 12-mm length and 0.6% fibre-weight produced the top performing hybrid fibre intumescent formulation. The hybrid fibres form survived at elevated temperature, hence helped to provide structure and strengthen the char with the highest fire resistance was recorded at steel temperature of 197°C.

  11. Bitumen on Water: Charred Hay as a PFD (Petroleum Flotation Device

    Directory of Open Access Journals (Sweden)

    Nusrat Jahan

    2015-10-01

    Full Text Available Global demand for petroleum keeps increasing while traditional supplies decline. One alternative to the use of conventional crude oils is the utilization of Canadian bitumen. Raw bitumen is a dense, viscous, semi-liquid that is diluted with lighter crude oil to permit its transport through pipelines to terminals where it can then be shipped to global markets. When spilled, it naturally weathers to its original form and becomes dense enough to sink in aquatic systems. This severely limits oil spill recovery and remediation options. Here we report on the application of charred hay as a method for modifying the surface behavior of bitumen in aquatic environments. Waste or surplus hay is abundant in North America. Its surface can easily be modified through charring and/or chemical treatment. We have characterized the modified and charred hay using solid-state NMR, contact angle measurements and infrared spectroscopy. Tests of these materials to treat spilled bitumen in model aquatic systems have been undertaken. Our results indicate that bitumen spills on water will retain their buoyancy for longer periods after treatment with charred hay, or charred hay coated with calcium oxide, improving recovery options.

  12. Abundant and stable char residues in soils: implications for soil fertility and carbon sequestration.

    Science.gov (United States)

    Mao, J-D; Johnson, R L; Lehmann, J; Olk, D C; Neves, E G; Thompson, M L; Schmidt-Rohr, K

    2012-09-01

    Large-scale soil application of biochar may enhance soil fertility, increasing crop production for the growing human population, while also sequestering atmospheric carbon. But reaching these beneficial outcomes requires an understanding of the relationships among biochar's structure, stability, and contribution to soil fertility. Using quantitative (13)C nuclear magnetic resonance (NMR) spectroscopy, we show that Terra Preta soils (fertile anthropogenic dark earths in Amazonia that were enriched with char >800 years ago) consist predominantly of char residues composed of ~6 fused aromatic rings substituted by COO(-) groups that significantly increase the soils' cation-exchange capacity and thus the retention of plant nutrients. We also show that highly productive, grassland-derived soils in the U.S. (Mollisols) contain char (generated by presettlement fires) that is structurally comparable to char in the Terra Preta soils and much more abundant than previously thought (~40-50% of organic C). Our findings indicate that these oxidized char residues represent a particularly stable, abundant, and fertility-enhancing form of soil organic matter. PMID:22834642

  13. INDUSTRIAL PROCESS VALIDATION OF SOLID ORAL DASAGE FORM: A REVIEW

    Directory of Open Access Journals (Sweden)

    Vishal Sharma

    2013-06-01

    Full Text Available Validation is the important step in gaining and maintaining the quality of the final product. Validation of the individual steps of the processes is called the process validation. Different dosage forms have different validation protocols. Validation is therefore is one element of quality assurance programs and is associated with a particular process therefore word validation simply means “assessment of validity” or action of proving effectiveness. Validation thus provides a higher degree of assurance that the manufacturing process consistently meets the pre-determined specifications and the quality products output can be used to increase productivity, its consistent quality and decreasing the need for processing and market complaints of the drug product. This overview examines the need for pharmaceutical validation, the various approaches and steps involved.

  14. Sulfur retention by ash during coal combustion. Part I. A model of char particle combustion

    Directory of Open Access Journals (Sweden)

    BORISLAV GRUBOR

    2003-02-01

    Full Text Available A model for the combustion of porous char particles as a basis for modeling the process of sulfur retention by ash during coal combustion is developed in this paper. The model belongs to the microscopic intrinsic models and describes the dynamic behavior of a porous char particle during comustion, taking into account temporal and spatial changes of all important physical properties of the char particle and various combustion parameters. The parametric analysis of the enhanced model shows that the model represents a good basis for the development of a model for the process of sulfur retention by ash during coal combustion. The model enables the prediction of the values of all parameters necessary for the introduction of reactions between sulfur compounds and mineral components in ash, primarily calcium oxide.

  15. The Ceramic Waste Form Process at the Idaho National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Ken Bateman; Stephen Priebe

    2006-08-01

    The treatment of spent nuclear fuel for disposition using an electrometallurgical technique results in two high-level waste forms: a ceramic waste form (CWF) and a metal waste form (MWF). The CWF is a composite of sodalite and glass, which stabilizes the active fission products (alkali, alkaline earths, and rare earths) and transuranic (TRU) elements. Reactive metal fuel constituents, including all the TRU metals and the majority of the fission products remain in the salt as chlorides and are processed into the CWF. The solidified salt is containerized and transferred to the CWF process where it is ground in an argon atmosphere. Zeolite 4A is dried in a mechanically-fluidized dryer to about 0.1 wt% moisture and ground to a particle-size range of 45µ to 250µ. The salt and zeolite are mixed in a V-mixer and heated to 500°C for about 18 hours. During this process, the salt occludes into the structure of the zeolite. The salt-loaded zeolite (SLZ) is cooled and then mixed with borosilicate glass frit with a comparable particle-size range. The SLZ/glass mixture is transferred to a crucible, which is placed in a furnace and heated to 925°C. During this process, known as pressureless consolidation, the zeolite is converted to the final sodalite form and the glass thoroughly encapsulates the sodalite, producing a dense, leach-resistant final waste form. During the last several years, changes have occurred to the process, including: particle size of input materials and conversion from hot isostatic pressing to pressureless consolidation, This paper is intended to provide the current status of the CWF process focusing on the adaptation to pressureless consolidation. Discussions will include impacts of particle size on final waste form and the pressureless consolidation cycle. A model will be presented that shows the heating and cooling cycles and the effect of radioactive decay heat on the amount of fission products that can be incorporated into the CWF.

  16. SiteChar - methodology for a fit-for-purpose assessment of CO2 storage sites in Europe

    International Nuclear Information System (INIS)

    The FP7-funded SiteChar project examined the entire CO2 geological storage site characterisation process, from the initial feasibility studies through to the final stage of application for a CO2 storage permit based on criteria defined by the relevant European legislation. The SiteChar work-flow for CO2 geological storage site characterisation provides a description of all elements of a site characterisation study, as well as guidance to streamline the site characterisation process and make sure that the output covers the aspects mentioned in the European Community (EC) Storage Directive. Five potential European storage sites, representative of prospective geological contexts, were considered as test sites for the research work: a North Sea multi-store site (hydrocarbon field and aquifer) offshore Scotland; an onshore aquifer in Denmark; an onshore gas field in Poland; an aquifer offshore in Norway; and an aquifer in the Southern Adriatic Sea. This portfolio combines complementary sites that allowed to encompass the different steps of the characterisation work-flow. A key innovation was the development of internal 'dry-run' permit applications at the Danish and Scottish sites and their review by relevant regulatory authorities. This process helped to refine the site characterisation work-flow, and aimed to identify remaining gaps in site-specific characterisation, needed to secure storage permits under the EC Storage Directive as implemented in 'host' Member States. SiteChar considered the important aspect of the public awareness and public opinions of these new technologies, in parallel to technical issues, on the onshore Polish and offshore Scottish sites. A new format to assist public opinion-forming processes was tested involving a small sample of local communities. Generic as well as site-specific information was made available to the general and local public via the internet and at information meetings. These exercises provide insight in

  17. Characterization of char derived from various types of solid wastes from the standpoint of fuel recovery and pretreatment before landfilling

    International Nuclear Information System (INIS)

    Carbonization is a kind of pyrolysis process to produce char from organic materials under an inert atmosphere. In this work, chars derived from various solid wastes were characterized from the standpoint of fuel recovery and pretreatment of waste before landfilling. Sixteen kinds of municipal and industrial solid wastes such as residential combustible wastes, non-combustible wastes, bulky wastes, construction and demolition wastes, auto shredder residue, and sludges were carbonized at 500 deg. C for 1 h under nitrogen atmosphere. In order to evaluate the quality of char as fuel, proximate analysis and heating value were examined. The composition of raw waste had a significant influence on the quality of produced char. The higher the ratio of woody biomass in waste, the higher heating value of char produced. Moreover, an equation to estimate heating value of char was developed by using the weight fraction of fixed carbon and volatile matter in char. De-ashing and chlorine removal were performed to improve the quality of char. The pulverization and sieving method seems to be effective for separation of incombustibles such as metal rather than ash. Most char met a 0.5 wt% chlorine criterion for utilization as fuel in a shaft blast furnace after it was subjected to repeated water-washing. Carbonization could remove a considerable amount of organic matter from raw waste. In addition, the leaching of heavy metals such as chrome, cadmium, and lead appears to be significantly suppressed by carbonization regardless of the type of raw waste. From these results, carbonization could be considered as a pretreatment method for waste before landfilling, as well as for fuel recovery

  18. Spray forming high speed steel - properties and processing

    International Nuclear Information System (INIS)

    The potential of spray forming (SF) for microstructural refining can be attractive to the production of high speed steels. The refined as-cast structure may lead to important improvements of material properties, compared to conventionally cast materials. The present work aimed to compare the properties of AISI M3:2 high speed steel produced through spray forming and conventional casting. Also, the processing of SF billet is considered, specifically the hot working conditions and its relation to carbide size. A round 400 mm diameter SF billet was produced using a twin atomiser. Characterisation was performed in the as-cast structure and after hot working to 116 mm squared bars and 11 mm diameter round bars. The results show that, compared to conventionally cast high speed steel, the SF material has higher isotropy in toughness due to its less oriented carbide distribution. Regarding processing procedures, time and temperature employed in heating before hot working also affect the microstructure of SF material

  19. Spray forming high speed steel - properties and processing

    Energy Technology Data Exchange (ETDEWEB)

    Mesquita, Rafael Agnelli; Barbosa, Celso Antonio

    2004-10-10

    The potential of spray forming (SF) for microstructural refining can be attractive to the production of high speed steels. The refined as-cast structure may lead to important improvements of material properties, compared to conventionally cast materials. The present work aimed to compare the properties of AISI M3:2 high speed steel produced through spray forming and conventional casting. Also, the processing of SF billet is considered, specifically the hot working conditions and its relation to carbide size. A round 400 mm diameter SF billet was produced using a twin atomiser. Characterisation was performed in the as-cast structure and after hot working to 116 mm squared bars and 11 mm diameter round bars. The results show that, compared to conventionally cast high speed steel, the SF material has higher isotropy in toughness due to its less oriented carbide distribution. Regarding processing procedures, time and temperature employed in heating before hot working also affect the microstructure of SF material.

  20. Effect of oxidation and other treatments on hydrogasification rate of coal char

    Energy Technology Data Exchange (ETDEWEB)

    Toomajian, M.E.; Lussier, M.G.; Miller, D.J. (Michigan State University, East Lansing, MI (USA). Dept. of Chemical Engineering)

    1992-09-01

    Hydrogasification of coal and other chars is a much slower process than steam or carbon dioxide gasification; moreover, the rate of gasification in pure hydrogen decreases sharply with conversion for most carbons. To better understand and overcome this rate behaviour, the effects of oxidation (partial burnoff in air at 375{degree}C), demineralization, heat treatment at 1000{degree}C and K{sub 2}CO{sub 3} addition on hydrogasification rate of Illinois No. 6 coal char and Saran char are investigated. Oxidation of partially hydrogasified or heat-treated chars results in up to a threefold increase in subsequent hydrogasification rate; the enhancement propagates for 5-10% conversion following oxidation. Partial burnoff prior to hydrogasifcation enhances the rate by only about 30% for 1-2% additional conversion. Addition of potassium carbonate catalyst eliminates the decay in rate for mineral-free chars. Oxidation and addition of catalyst enhance the rate of hydrogasification either by removing strongly chemisorbed hydrogen or by generating surface structure active in hydrogasification. 38 refs., 7 figs., 2 tabs.

  1. Melt processed multiphase ceramic waste forms for nuclear waste immobilization

    Science.gov (United States)

    Amoroso, Jake; Marra, James C.; Tang, Ming; Lin, Ye; Chen, Fanglin; Su, Dong; Brinkman, Kyle S.

    2014-11-01

    Ceramic waste forms are promising hosts for nuclear waste immobilization as they have the potential for increased durability and waste loading compared with conventional borosilicate glass waste forms. Ceramics are generally processed using hot pressing, spark plasma sintering, and conventional solid-state reaction, however such methods can be prohibitively expensive or impractical at production scales. Recently, melt processing has been investigated as an alternative to solid-state sintering methods. Given that melter technology is currently in use for High Level Waste (HLW) vitrification in several countries, the technology readiness of melt processing appears to be advantageous over sintering methods. This work reports the development of candidate multi-phase ceramic compositions processed from a melt. Cr additions, developed to promote the formation and stability of a Cs containing hollandite phase were successfully incorporated into melt processed multi-phase ceramics. Control of the reduction-oxidation (Redox) conditions suppressed undesirable Cs-Mo containing phases, and additions of Al and Fe reduced the melting temperature.

  2. PROCESS SIMULATION AND QUALITY EVALUATION IN INCREMENTAL SHEET FORMING

    Directory of Open Access Journals (Sweden)

    Meftah Hrairi

    2011-12-01

    Full Text Available Single Point Incremental Forming (SPIF is a promising sheet-metal-forming process that permits the manufacturing of small to medium-sized batches of complex parts at low cost. It allows metal forming to work in the critical ‘necking-to-tearing' zone which results in a strong thinning before failure if the process is well designed. Moreover, the process is complex due to the number of variables involved. Thus, it is not possible to consider that the process has been well assessed; several remaining aspects need to be clarified. The objective of the present paper is to study some of these aspects, namely, the phenomenon of the wall thickness overstretch along depth and the effect of the tool path on the distribution of the wall thickness using finite element simulations.Abstrak: Pembentukan Tokokan Mata Tunggal (Single Point Incremental Forming (SPIF merupakan satu proses pembentukan kepingan logam yang membolehkan pembuatan dalam jumlah yang kecil hingga sederhana, bahagian-bahagian yang kompleks pada kos yang rendah. Jika proses ini direka dengan baik, kaedah ini membolehkan pembentukan logam yang baik terhasil. Jika tidak, semasa peringkat zon kritikal ‘perleheran-ke-pengoyakan' menyebabkan penipisan keterlaluan yang boleh menyebabkan logam tersebut rosak. Tambahan pula, proses ini agak kompleks, kerana ia melibatkan beberapa pemboleh ubah. Maka, walaupun proses ini telah dinilaikan seeloknya; masih terdapat beberapa aspek lain yang perlu diperjelaskan. Objektif kertas ini dibentangkan adalah untuk mengkaji beberapa aspek tertentu, seperti, ketebalan dinding regangan berlebihan di sepanjang kedalaman dan kesan tool path (beberapa siri posisi koordinat untuk menentukan pergerakan alatan memotong ketika operasi memesin terhadap pengagihan ketebalan dinding menggunakan simulasi unsur terhingga.

  3. Process for forming synapses in neural networks and resistor therefor

    Science.gov (United States)

    Fu, Chi Y.

    1996-01-01

    Customizable neural network in which one or more resistors form each synapse. All the resistors in the synaptic array are identical, thus simplifying the processing issues. Highly doped, amorphous silicon is used as the resistor material, to create extremely high resistances occupying very small spaces. Connected in series with each resistor in the array is at least one severable conductor whose uppermost layer has a lower reflectivity of laser energy than typical metal conductors at a desired laser wavelength.

  4. Numerical simulation and experimental investigation of incremental sheet forming process

    Institute of Scientific and Technical Information of China (English)

    HAN Fei; MO Jian-hua

    2008-01-01

    In order to investigate the process of incremental sheet forming (ISF) through both experimental and numerical approaches, a three-dimensional elasto-plastic finite element model (FEM) was developed to simulate the process and the simulated results were compared with those of experiment. The results of numerical simulations, such as the strain history and distribution, the stress state and distribution, sheet thickness distribution, etc, were discussed in details, and the influences of process parameters on these results were also analyzed. The simulated results of the radial strain and the thickness distribution are in good agreement with experimental results. The simulations reveal that the deformation is localized around the tool and constantly remains close to a plane strain state. With decreasing depth step, increasing tool diameter and wall inclination angle, the axial stress reduces, leading to less thinning and more homogeneous plastic strain and thickness distribution. During ISF, the plastic strain increases stepwise under the action of the tool. Each increase in plastic strain is accompanied by hydrostatic pressure, which explains why obtainable deformation using ISF exceeds the forming limits of conventional sheet forming.

  5. Electrochemical/Pyrometallurgical Waste Stream Processing and Waste Form Fabrication

    Energy Technology Data Exchange (ETDEWEB)

    Steven Frank; Hwan Seo Park; Yung Zun Cho; William Ebert; Brian Riley

    2015-07-01

    This report summarizes treatment and waste form options being evaluated for waste streams resulting from the electrochemical/pyrometallurgical (pyro ) processing of used oxide nuclear fuel. The technologies that are described are South Korean (Republic of Korea – ROK) and United States of America (US) ‘centric’ in the approach to treating pyroprocessing wastes and are based on the decade long collaborations between US and ROK researchers. Some of the general and advanced technologies described in this report will be demonstrated during the Integrated Recycle Test (IRT) to be conducted as a part of the Joint Fuel Cycle Study (JFCS) collaboration between US Department of Energy (DOE) and ROK national laboratories. The JFCS means to specifically address and evaluated the technological, economic, and safe guard issues associated with the treatment of used nuclear fuel by pyroprocessing. The IRT will involve the processing of commercial, used oxide fuel to recover uranium and transuranics. The recovered transuranics will then be fabricated into metallic fuel and irradiated to transmutate, or burn the transuranic elements to shorter lived radionuclides. In addition, the various process streams will be evaluated and tested for fission product removal, electrolytic salt recycle, minimization of actinide loss to waste streams and waste form fabrication and characterization. This report specifically addresses the production and testing of those waste forms to demonstrate their compatibility with treatment options and suitability for disposal.

  6. FE analysis of tube forming process with experimental verification

    Directory of Open Access Journals (Sweden)

    V. Mandic

    2006-08-01

    Full Text Available Purpose: of this paper: The paper presents some results of extensive investigation of steel seam-welded tubesforming process, by applying combined treatment of material narrowing and expansion. The objective ofexecuted numerical FE and experimental investigations was to determine the optimal technology for productionof tubular product at simple tools and at the standard forming processing machines, without defects and withdemanded dimensional accuracy.Design/methodology/approach: Tube forming was done in one phase, in tool with two shaping spherical parts,that enables the expansion of the specimen’s central zone and the filling of the die due to narrowing of thespecimen ends, when certain conditions are achieved and with appropriate combination of influential processparameters (outer diameter, height and tube’s wall thickness, as well as friction conditions. Series of physicaland numerical FE experiments was performed.Findings: Optimal dimensions of tubular product, with required process stability, were obtained this way. Also,results of experiments pointed out that the best process stability and die filling is achieved with specimenswhose surfaces had previously been chemically treated. Results of numerical FE simulations of process arequite verified by experiments.Practical implications: Obtained results have practical significance in solving similar processing problems. Italso enables to investigate and broaden the knowledge on stability of these kinds of processes, beyond the scopeof experimental investigations. Tubular product that is subjected to numerical-experimental investigation in thispaper is prepared by narrowing it at both ends thus excluding the possibility to apply holder inside the tube.Originality/value: Proposed method offers possibility for production of tubular products at simple formingmachines and tools, without complex and expensive hydroforming equipment.

  7. Characterization of char derived from various types of solid wastes from the standpoint of fuel recovery and pretreatment before landfilling

    OpenAIRE

    Hwang, I. H.; Matsuto, T.; Tanaka, N; Sasaki, Y; Tanaami, K.

    2007-01-01

    Carbonization is a kind of pyrolysis process to produce char from organic materials under an inert atmosphere. In this work, chars derived from various solid wastes were characterized from the standpoint of fuel recovery and pretreatment of waste before landfilling. Sixteen kinds of municipal and industrial solid wastes such as residential combustible wastes, non-combustible wastes, bulky wastes, construction and demolition wastes, auto shredder residue, and sludges were carbonized at 500℃ fo...

  8. Process Parameters Optimization in Single Point Incremental Forming

    Science.gov (United States)

    Gulati, Vishal; Aryal, Ashmin; Katyal, Puneet; Goswami, Amitesh

    2016-04-01

    This work aims to optimize the formability and surface roughness of parts formed by the single-point incremental forming process for an Aluminium-6063 alloy. The tests are based on Taguchi's L18 orthogonal array selected on the basis of DOF. The tests have been carried out on vertical machining center (DMC70V); using CAD/CAM software (SolidWorks V5/MasterCAM). Two levels of tool radius, three levels of sheet thickness, step size, tool rotational speed, feed rate and lubrication have been considered as the input process parameters. Wall angle and surface roughness have been considered process responses. The influential process parameters for the formability and surface roughness have been identified with the help of statistical tool (response table, main effect plot and ANOVA). The parameter that has the utmost influence on formability and surface roughness is lubrication. In the case of formability, lubrication followed by the tool rotational speed, feed rate, sheet thickness, step size and tool radius have the influence in descending order. Whereas in surface roughness, lubrication followed by feed rate, step size, tool radius, sheet thickness and tool rotational speed have the influence in descending order. The predicted optimal values for the wall angle and surface roughness are found to be 88.29° and 1.03225 µm. The confirmation experiments were conducted thrice and the value of wall angle and surface roughness were found to be 85.76° and 1.15 µm respectively.

  9. Adsorption of Pb(II by Activated Pyrolytic Char from Used Tire

    Directory of Open Access Journals (Sweden)

    Lu Ping

    2016-01-01

    Full Text Available As a renewable resource, the pyrolytic char derived from used tire has promising adsorption capacities owing to its similar structure and properties with active carbon. The purification and activation of the pyrolytic char from used tire, as well as the application of this material in the adsorption of Pb(II in water is conducted. The influences on the adsorption capacity by temperature and pH value are investigated and discussed; the adsorption thermodynamics and kinetics are also studied. The results show that the pyrolytic char from used tire has remarkable adsorption capacity for Pb(II, and the adsorption is an endothermic process complying with the Langmuir isotherm. The adsorption kinetics is a pseudo second-order reaction.

  10. Fuel gas and char from pyrolysis of waste paper in a microwave plasma reactor

    Energy Technology Data Exchange (ETDEWEB)

    Khongkrapan, Parin; Thanompongchart, Patipat; Tippayawong, Nakorn; Kiatsiriroat, Tanongkiat [Department of Mechanical Engineering, Faculty of Engineering, Chiang Mai University, Chiang Mai 50200 (Thailand)

    2013-07-01

    In this study, a microwave plasma reactor was used for pyrolysis of waste papers. The effects of different argon flow rates on char and gas generation were investigated. Changes in carbon and oxygen contents from those in paper to char were significant. Char yield of over 25 % was obtained with the heating value of about 38 MJ/kg. Average gas yield and total content of combustible fraction (CO, CH4 and H2) in the gas product were 2.56 m3/kg and 36 %, respectively. The heating value of gas product and carbon conversion efficiency of the process were maximum at 6.0 MJ/m3 and 73 %, respectively.

  11. Fuel gas and char from pyrolysis of waste paper in a microwave plasma reactor

    Directory of Open Access Journals (Sweden)

    Parin Khongkrapan, Patipat Thanompongchart, Nakorn Tippayawong, Tanongkiat Kiatsiriroat

    2013-01-01

    Full Text Available In this study, a microwave plasma reactor was used for pyrolysis of waste papers. The effects of different argon flow rates on char and gas generation were investigated. Changes in carbon and oxygen contents from those in paper to char were significant. Char yield of over 25 % was obtained with the heating value of about 38 MJ/kg. Average gas yield and total content of combustible fraction (CO, CH4 and H2 in the gas product were 2.56 m3/kg and 36 %, respectively. The heating value of gas product and carbon conversion efficiency of the process were maximum at 6.0 MJ/m3 and 73 %, respectively.

  12. Production of Bio char with High Mineral Content from Oil Palm Biomass

    International Nuclear Information System (INIS)

    Carbonization of oil palm empty fruit bunch (OPEFB) biomass for the production of high mineral content bio char under an uncontrolled carbonization temperature and controlled air flow rate was studied using a pilot-scale brick carbonization reactor. The maximum temperature during the carbonization process was found to be in the range of 543 to 564 degree Celsius at exhaust gas flow rate of 36 m3/ hr. All minerals (for example P, K ,Mg, Ca, Na, Mn, Fe, Cr, AI) showed an increased from the feedstock concentration up to 300 %. The concentration of heavy metal extracted from OPEFB bio char was lower than listed ceiling permitted levels. This proposed system without electrical control and heating source is preferable to the industry due to its simplicity, ease of operation and low energy requirement making it suitable for OPEFB bio char production for mulching purposes with more than double the mineral content compared to raw OPEFB biomass. (author)

  13. Carborane Dopant Strengthens Pitch Char

    Science.gov (United States)

    Brown, D. Kyle

    1992-01-01

    Addition of small amount of soluble, organic boron compound to matrix precursor of carbon-fiber/carbon-matrix (carbon/carbon) composite increases strength and toughness of composite. Compound catalyzes graphitization of matrix, giving rise to greater degree of graphitization at lower processing temperature. Technique used to advantage in carbon/carbon materials requiring lower temperature processing, such as those with inhibited matrices or materials sensitive to changes in fiber properties.

  14. Production and Characterization of Bio-Char from the Pyrolysis of Empty Fruit Bunches

    OpenAIRE

    Mohamad A. Sukiran; Loh S. Kheang; Nasrin A. Bakar; Choo Y. May

    2011-01-01

    Problem statement: The palm oil industry generates an abundance of oil palm biomass such as the Empty Fruit Bunch (EFB), shell, frond, trunk and Palm Oil Mill Effluent (POME). For 88 million tones of Fresh Fruit Bunch (FFB) processed in 2008, the amount of oil palm biomass was more than 26 million tones. Studies about production of bio-char from oil palm biomass are still lacking in Malaysia. So, this study was aimed to: (i) determine the effect of pyrolysis temperatures on bio-char yield (ii...

  15. [Analysis on the target product from sewage sludge pyrolysis and experiments on using the char for enhancing plant cultivation].

    Science.gov (United States)

    Song, Xue-Ding; Chen, De-Zhen; Wang, Zhong-Hui; He, Wei

    2011-09-01

    Characteristics of sewage sludge pyrolysis under low temperatures were studied and the influences of reaction temperature and moisture content on products distribution and their properties were also investigated with a purpose to select a proper target product. After a dissective comparison, char produced from the pyrolysis process was chosen as the target product and then its effect on plant cultivation was checked by using it to plant garlic when blended into normal soil; also its heavy metals contents and their transfer to the garlic were investigated. The primary research results showed that with the moisture content reduced to a certain level, char production was above 40% of sewage sludge when the pyrolysis process took place under 550 degrees C; ash content of the char is around 60% - 65%, but it is rich with nitrogen, phosphorus and potassium contents. The heavy metal contents in the char meet up with the limitations for land use, and the garlic stems planted in the soil blended with the char grew much faster than those planted in normal soil with their averaged height being 3-4 cm higher; however the heavy metal contents in the fast-growing garlic stems were a little higher than that in the normal ones, which was not suitable for edible plants. The results obtained suggested that char produced from sewage sludge pyrolysis process could be a target product arranged for land use especially for non-edible plant cultivation. PMID:22165228

  16. Upgrading the rice husk char obtained by flash pyrolysis for the production of amorphous silica and high quality activated carbon.

    Science.gov (United States)

    Alvarez, Jon; Lopez, Gartzen; Amutio, Maider; Bilbao, Javier; Olazar, Martin

    2014-10-01

    The overall valorization of rice husk char obtained by flash pyrolysis in a conical spouted bed reactor (CSBR) has been studied in a two-step process. Thus, silica has been recovered in a first step and the remaining carbon material has been subjected to steam activation. The char samples used in this study have been obtained by continuous flash pyrolysis in a conical spouted bed reactor at 500°C. Extraction with Na2CO3 allows recovering 88% of the silica contained in the rice husk char. Activation of the silica-free rice husk char has been carried out in a fixed bed reactor at 800°C using steam as activating agent. The porous structure of the activated carbons produced includes a combination of micropores and mesopores, with a BET surface area of up to 1365m(2)g(-1) at the end of 15min.

  17. Upgrading the rice husk char obtained by flash pyrolysis for the production of amorphous silica and high quality activated carbon.

    Science.gov (United States)

    Alvarez, Jon; Lopez, Gartzen; Amutio, Maider; Bilbao, Javier; Olazar, Martin

    2014-10-01

    The overall valorization of rice husk char obtained by flash pyrolysis in a conical spouted bed reactor (CSBR) has been studied in a two-step process. Thus, silica has been recovered in a first step and the remaining carbon material has been subjected to steam activation. The char samples used in this study have been obtained by continuous flash pyrolysis in a conical spouted bed reactor at 500°C. Extraction with Na2CO3 allows recovering 88% of the silica contained in the rice husk char. Activation of the silica-free rice husk char has been carried out in a fixed bed reactor at 800°C using steam as activating agent. The porous structure of the activated carbons produced includes a combination of micropores and mesopores, with a BET surface area of up to 1365m(2)g(-1) at the end of 15min. PMID:25127010

  18. Metal forming processes to produce ECN superconducting wire

    Energy Technology Data Exchange (ETDEWEB)

    Schaap, E.C.M.E.

    1991-01-01

    The main subject is modelling techniques for metal forming processes. Attention is paid to wire drawing and tube sinking. Part 1 presents the necessary mechanical background. Chapter 2 concerns the issues of the wire drawing of homogeneous isotropic material. Analytic as well as numerical approaches for modelling metal forming processes are discussed in chapter 3, each with their advantages and deficiencies. In Part 2 the applications of the simple upper-bound methods are discussed thoroughly, not because they are expected to bring the ultimate answer in solving deformation problems, but because they can bring some clarity quickly, since they are easy to apply. The upper-bound method applied on wire drawing is discussed in chapter 4; the significance of tube sinking theories is demonstrated in chapter 5 and bi-metal wire drawing in chapter 6. With the aid of the formulas based on these theories, FORTRAN programs for tube sinking and the criterion of core fraction in drawing bi-metal wire have been developed. Their purpose is explained. The finite element method will be discussed in a future report more extensively. In the last chapters some concluding remarks are made on the selection of appropriate values for process and material parameters as to produce sound wire. Recommendations are given for further research. 58 figs., 16 refs., 2 tabs.

  19. Crystallization behavior during melt-processing of ceramic waste forms

    Science.gov (United States)

    Tumurugoti, Priyatham; Sundaram, S. K.; Misture, Scott T.; Marra, James C.; Amoroso, Jake

    2016-05-01

    Multiphase ceramic waste forms based on natural mineral analogs are of great interest for their high chemical durability, radiation resistance, and thermodynamic stability. Melt-processed ceramic waste forms that leverage existing melter technologies will broaden the available disposal options for high-level nuclear waste. This work reports on the crystallization behavior in selected melt-processed ceramics for waste immobilization. The phase assemblage and evolution of hollandite, zirconolite, pyrochlore, and perovskite type structures during melt processing were studied using thermal analysis, x-ray diffraction, and electron microscopy. Samples prepared by melting followed by annealing and quenching were analyzed to determine and measure the progression of the phase assemblage. Samples were melted at 1500 °C and heat-treated at crystallization temperatures of 1285 °C and 1325 °C corresponding to exothermic events identified from differential scanning calorimetry measurements. Results indicate that the selected multiphase composition partially melts at 1500 °C with hollandite coexisting as crystalline phase. Perovskite and zirconolite phases crystallized from the residual melt at temperatures below 1350 °C. Depending on their respective thermal histories, different quenched samples were found to have different phase assemblages including phases such as perovskite, zirconolite and TiO2.

  20. Review of Approximate Analyses of Sheet Forming Processes

    Science.gov (United States)

    Weiss, Matthias; Rolfe, Bernard; Yang, Chunhui; de Souza, Tim; Hodgson, Peter

    2011-08-01

    Approximate models are often used for the following purposes: • in on-line control systems of metal forming processes where calculation speed is critical; • to obtain quick, quantitative information on the magnitude of the main variables in the early stages of process design; • to illustrate the role of the major variables in the process; • as an initial check on numerical modelling; and • as a basis for quick calculations on processes in teaching and training packages. The models often share many similarities; for example, an arbitrary geometric assumption of deformation giving a simplified strain distribution, simple material property descriptions—such as an elastic, perfectly plastic law—and mathematical short cuts such as a linear approximation of a polynomial expression. In many cases, the output differs significantly from experiment and performance or efficiency factors are developed by experience to tune the models. In recent years, analytical models have been widely used at Deakin University in the design of experiments and equipment and as a pre-cursor to more detailed numerical analyses. Examples that are reviewed in this paper include deformation of sandwich material having a weak, elastic core, load prediction in deep drawing, bending of strip (particularly of ageing steel where kinking may occur), process analysis of low-pressure hydroforming of tubing, analysis of the rejection rates in stamping, and the determination of constitutive models by an inverse method applied to bending tests.

  1. Optimum Design Of Addendum Surfaces In Sheet Metal Forming Process

    Science.gov (United States)

    Debray, K.; Sun, Z. C.; Radjai, R.; Guo, Y. Q.; Dai, L.; Gu, Y. X.

    2004-06-01

    The design of addendum surfaces in sheet forming process is very important for the product quality, but it is very time-consuming and needs tedious trial-error corrections. In this paper, we propose a methodology to automatically generate the addendum surfaces and then to optimize them using a forming modelling solver. The surfaces' parameters are taken as design variables and modified in course of optimization. The finite element mesh is created on the initial addendum surfaces and mapped onto the modified surfaces without remeshing operation. The Feasible Sequential Quadratic Programming (FSQP) is adopted as our algorithm of optimization. Two objective functions are used: the first one is the thickness function to minimize the thickness variation on the workpiece ; the second one is the appearance function aiming to avoid the scratching defects on the external surfaces of panels. The FSQP is combined with our "Inverse Approach" or "One Step Approach" which is a very fast forming solver. This leads to a very efficient optimization procedure. The present methodology is applied to a square box. The addendum surfaces are characterised by four geometrical variables. The influence of optimization criteria is studied and discussed.

  2. Modification to the MAPS interview process and electronic form

    CERN Multimedia

    HR Department

    2006-01-01

    Based on the first year of experience with e-MAPS and the feedback from departmental users, a number of modifications to the MAPS interview process and the form have been introduced for the 2006 exercise. Definition of signatories The top of the form now also shows the name of the group leader and department head. This is especially useful in cases of detachment. Corrections can be made via the MAPS Coordinator. 'Send back' facility The possibility to send the MAPS report one step backwards is only available to the MAPS coordinators, i.e., from group leader to supervisor, from staff member to group leader, and from group leader to staff member. The form should only be sent back to correct factual errors or oversights, and any send backs will be tracked. Link 'training' part to 'training' application When entering a training objective for 2006, a search menu allows selection from various CERN internal training courses or from conferences. It remains important however to first read the description of the...

  3. Modification to the MAPS interview process and electronic form

    CERN Multimedia

    HR Department

    2006-01-01

    Based on the first year of experience with e-MAPS and the feedback from departmental users, a number of modifications to the MAPS interview process and form have been introduced for the 2006 exercise. Definition of signatories The top of the form now also shows the name of the Group Leader and Department Head. This is especially useful in cases of detachment. Corrections can be made via the MAPS Coordinator. 'Send back' facility The possibility to send the MAPS report one step backwards, i.e. from Group Leader to supervisor, from Staff Member to Group Leader, and from Group Leader to Staff Member is only available to the MAPS coordinators. The form should only be sent back to correct factual errors or oversights, and any send- backs will be recorded. Link between 'training' part and 'training' application When entering a training objective for 2006, a search menu allows selection from various CERN internal training courses or from conferences. It is still important, however, to first read the descri...

  4. Comparative Study between Programming Systems for Incremental Sheet Forming Process

    Directory of Open Access Journals (Sweden)

    Moayedfar Majid

    2014-07-01

    Full Text Available Incremental Sheet Forming (ISF is a method developed to form a desired surface feature on sheet metals in batch production series. Due to a lack of dedicated programming system to execute, control and monitor the whole ISF, researchers tried to utilize programming systems designed for chip making process to suits for ISF. In this work, experiments were conducted to find suitability and quality of ISF parts produced by using manual CNC part programming. Therefore, ISF was carried out on stainless steel sheets using Computer Numerical Control (CNC milling machines. Prior to running the experiments, a ball-point shaped tool made of bronze alloy was fabricated due to its superior ability to reduce the amount of friction and improve the surface quality of the stainless steel sheet metal. The experiments also employed the method of forming in negative direction with a blank mould and the tool which helped to shape the desired part quickly. The programming was generated using the MasterCAM software for the CNC milling machine and edited before transferring to the machine. However, the programming for the machine was written manually to show the differences of output date between software programming and manual programming. From the results, best method of programming was found and minimum amount of contact area between tool and sheet metal achieved.

  5. Crystalline Ceramic Waste Forms: Comparison Of Reference Process For Ceramic Waste Form Fabrication

    Energy Technology Data Exchange (ETDEWEB)

    Brinkman, K. S. [Savannah River National Laboratory; Marra, J. C. [Savannah River National Laboratory; Amoroso, J. [Savannah River National Laboratory; Tang, M. [Los Alamos National Laboratory

    2013-08-22

    The research conducted in this work package is aimed at taking advantage of the long term thermodynamic stability of crystalline ceramics to create more durable waste forms (as compared to high level waste glass) in order to reduce the reliance on engineered and natural barrier systems. Durable ceramic waste forms that incorporate a wide range of radionuclides have the potential to broaden the available disposal options and to lower the storage and disposal costs associated with advanced fuel cycles. Assemblages of several titanate phases have been successfully demonstrated to incorporate radioactive waste elements, and the multiphase nature of these materials allows them to accommodate variation in the waste composition. Recent work has shown that they can be produced from a melting and crystallization process. The objective of this report is to explore the phase formation and microstructural differences between lab scale melt processing in varying gas environments with alternative densification processes such as Hot Pressing (HP) and Spark Plasma Sintering (SPS). The waste stream used as the basis for the development and testing is a simulant derived from a combination of the projected Cs/Sr separated stream, the Trivalent Actinide - Lanthanide Separation by Phosphorous reagent Extraction from Aqueous Komplexes (TALSPEAK) waste stream consisting of lanthanide fission products, the transition metal fission product waste stream resulting from the transuranic extraction (TRUEX) process, and a high molybdenum concentration with relatively low noble metal concentrations. Melt processing as well as solid state sintering routes SPS and HP demonstrated the formation of the targeted phases; however differences in microstructure and elemental partitioning were observed. In SPS and HP samples, hollandite, pervoskite/pyrochlore, zirconolite, metallic alloy and TiO{sub 2} and Al{sub 2}O{sub 3} were observed distributed in a network of fine grains with small residual pores

  6. Preparation of effective lignite chars for SO{sub 2} adsorption

    Energy Technology Data Exchange (ETDEWEB)

    Zimny, T.; Finqueneisel, G.; Weber, J.V. [Metz Univ. (France). Lab. de Chimi Industrielle; Izquierdo, M.T. [Departemento Energia y Medio Ambiente, Zaragoza (Spain). Inst. de Carboquimica

    1999-12-01

    The objective of this work was to determine the efficiency of activated chars produced from two different lignites to remove sulfur dioxide from industrial flue gas. The lignites used differ mainly in their ashes and water contents. The chars were produced at semi-pilot scale (0.5 t) in rotary kiln, and in our optimized conditions of temperature, the specific surface reaches 372 m{sup 2}/g (pyrolysis temperature 800 C) for the best char. In order to investigate the effect of surface oxigenated groups, a simple and mild post-oxidation treatment (40 min at 320 C in air) was performed. The dynamic adsorption of SO{sub 2} was realized at 100 C in controlled atmosphere containing O{sub 2}, H{sub 2}O, SO{sub 2} and N{sub 2} as a balance. In these conditions 70 mg SO{sub 2}/g can be adsorbed by the best sample. After six adsorption/desorption cycles for the best char, the decrease of adsorption capacity is close to 20%. The oxidation of the char surface leads to a sensible decrease of its adsorption capacity. This could be explained by a simultaneous increase of the basic surface groups which should enhanced SO{sub 2} adsorption and acidic groups which seem to be involved in the deactivation process. The influence of lignite pre-drying (before pyrolysis) on adsorption behavior of char is limited. Finally, once more, the lack of relation between surface area and SO{sub 2} adsorption capacity is observed. That means that considering polar and acidic molecules, both porosity and surface chemistry play important role. (orig.)

  7. Development, Verification and Validation of Enclosure Radiation Capabilities in the CHarring Ablator Response (CHAR) Code

    Science.gov (United States)

    Salazar, Giovanni; Droba, Justin C.; Oliver, Brandon; Amar, Adam J.

    2016-01-01

    With the recent development of multi-dimensional thermal protection system (TPS) material response codes including the capabilities to account for radiative heating is a requirement. This paper presents the recent efforts to implement such capabilities in the CHarring Ablator Response (CHAR) code developed at NASA's Johnson Space Center. This work also describes the different numerical methods implemented in the code to compute view factors for radiation problems involving multiple surfaces. Furthermore, verification and validation of the code's radiation capabilities are demonstrated by comparing solutions to analytical results, to other codes, and to radiant test data.

  8. Preliminary evaluation of alternative waste form solidification processes. Volume I. Identification of the processes.

    Energy Technology Data Exchange (ETDEWEB)

    Treat, R.L.; Nesbitt, J.F.; Blair, H.T.; Carter, J.G.; Gorton, P.S.; Partain, W.L.; Timmerman, C.L.

    1980-04-01

    This document contains preconceptual design data on 11 processes for the solidification and isolation of nuclear high-level liquid wastes (HLLW). The processes are: in-can glass melting (ICGM) process, joule-heated glass melting (JHGM) process, glass-ceramic (GC) process, marbles-in-lead (MIL) matrix process, supercalcine pellets-in-metal (SCPIM) matrix process, pyrolytic-carbon coated pellets-in-metal (PCCPIM) matrix process, supercalcine hot-isostatic-pressing (SCHIP) process, SYNROC hot-isostatic-pressing (SYNROC HIP) process, titanate process, concrete process, and cermet process. For the purposes of this study, it was assumed that each of the solidification processes is capable of handling similar amounts of HLLW generated in a production-sized fuel reprocessing plant. It was also assumed that each of the processes would be enclosed in a shielded canyon or cells within a waste facility located at the fuel reprocessing plant. Finally, it was assumed that all of the processes would be subject to the same set of regulations, codes and standards. Each of the solidification processes converts waste into forms that may be acceptable for geological disposal. Each process begins with the receipt of HLLW from the fuel reprocessing plant. In this study, it was assumed that the original composition of the HLLW would be the same for each process. The process ends when the different waste forms are enclosed in canisters or containers that are acceptable for interim storage. Overviews of each of the 11 processes and the bases used for their identification are presented in the first part of this report. Each process, including its equipment and its requirements, is covered in more detail in Appendices A through K. Pertinent information on the current state of the art and the research and development required for the implementation of each process are also noted in the appendices.

  9. Preliminary evaluation of alternative waste form solidification processes. Volume I. Identification of the processes

    International Nuclear Information System (INIS)

    This document contains preconceptual design data on 11 processes for the solidification and isolation of nuclear high-level liquid wastes (HLLW). The processes are: in-can glass melting (ICGM) process, joule-heated glass melting (JHGM) process, glass-ceramic (GC) process, marbles-in-lead (MIL) matrix process, supercalcine pellets-in-metal (SCPIM) matrix process, pyrolytic-carbon coated pellets-in-metal (PCCPIM) matrix process, supercalcine hot-isostatic-pressing (SCHIP) process, SYNROC hot-isostatic-pressing (SYNROC HIP) process, titanate process, concrete process, and cermet process. For the purposes of this study, it was assumed that each of the solidification processes is capable of handling similar amounts of HLLW generated in a production-sized fuel reprocessing plant. It was also assumed that each of the processes would be enclosed in a shielded canyon or cells within a waste facility located at the fuel reprocessing plant. Finally, it was assumed that all of the processes would be subject to the same set of regulations, codes and standards. Each of the solidification processes converts waste into forms that may be acceptable for geological disposal. Each process begins with the receipt of HLLW from the fuel reprocessing plant. In this study, it was assumed that the original composition of the HLLW would be the same for each process. The process ends when the different waste forms are enclosed in canisters or containers that are acceptable for interim storage. Overviews of each of the 11 processes and the bases used for their identification are presented in the first part of this report. Each process, including its equipment and its requirements, is covered in more detail in Appendices A through K. Pertinent information on the current state of the art and the research and development required for the implementation of each process are also noted in the appendices

  10. Effects of fresh and aged chars from pyrolysis and hydrothermal carbonization on nutrient sorption in agricultural soils

    Science.gov (United States)

    Gronwald, M.; Don, A.; Tiemeyer, B.; Helfrich, M.

    2015-06-01

    Leaching of nutrients from agricultural soils causes major environmental problems that may be reduced with amendments of chars derived from pyrolysis (pyrochars) or hydrothermal carbonization (hydrochars). Chars are characterized by a high adsorption capacity - i.e. they may retain nutrients such as nitrate and ammonium. However, the physicochemical properties of the chars and hence their sorption capacity likely depend on feedstock and the production process. We investigated the nutrient retention capacity of pyrochars and hydrochars from three different feedstocks (digestates, Miscanthus, woodchips) mixed into different soil substrates (sandy loam and silty loam). Moreover, we investigated the influence of char degradation on its nutrient retention capacity using a 7-month in situ field incubation of pyrochar and hydrochar mixed into soils at three different field sites. Pyrochars showed the highest ability to retain nitrate, ammonium and phosphate, with pyrochar from woodchips being particularly efficient in nitrate adsorption. Ammonium adsorption of pyrochars was controlled by the soil type of the soil-char mixture. We found some ammonium retention on sandy soils, but no pyrochar effect or even ammonium leaching from the loamy soil. The phosphate retention capacity of pyrochars strongly depended on the pyrochar feedstock with large phosphate leaching from digestate-derived pyrochar and some adsorption capacity from woodchip-derived pyrochar. Application of hydrochars to agricultural soils caused small, and often not significant, effects on nutrient retention. In contrast, some hydrochars did increase the leaching of nutrients compared to the non-amended control soil. We found a surprisingly rapid loss of the chars' adsorption capacity after field application of the chars. For all sites and for hydrochar and pyrochar, the adsorption capacity was reduced by 60-80 % to less or no nitrate and ammonium adsorption. Thus, our results cast doubt on the efficiency of

  11. Porous structure and morphology of granular chars from flash and conventional pyrolysis of grape seeds

    International Nuclear Information System (INIS)

    This work studies the influence of the operating conditions used in the pyrolysis of grape seeds on the morphology and textural properties of the chars resulting. Flash and conventional (283 K min−1 heating rate) pyrolysis have been used within a wide range of temperature (300–1000 °C). The effect of a pretreatment for oil extraction has also been studied. The porous structure of the chars was characterized by adsorption of N2 at 77 K, Ar at 77 K and 87 K, and CO2 at 273 K and mercury intrusion porosimetry. The morphology was analyzed by scanning electron microscopy. All the materials prepared revealed an essentially microporous structure, with a poor or even negligible contribution of mesopores. Increasing pyrolysis temperature led to higher specific surface areas and lower pore size. The highest specific surface area values occurred within 700–800 °C, reaching up to 500 m2 g−1 with pore sizes in the 0.4–1.1 nm range. No significant morphological changes were observed upon carbonization so that the resulting chars were granular materials of similar size than the starting grape seeds. The hollow core structure of the chars, with most of the material allocated at the periphery of the granules can help to overcome the mass transfer limitations of most common (solid or massive) granular activated carbons. The chars showed a good mechanical strength during attrition tests. These chars can be potential candidates for the preparation of granular carbons molecular sieve or activated carbons raw materials. -- Highlights: •We use a raw material that has a very low price and a high availability. •Not very much attention has been paid to this waste for carbonaceous materials preparation. •The chars obtained have high specific surface area that is an interesting starting point for later activation processes. •The chars show a micro-macro porous bimodal distribution. •Pyrolysis does not affect to morphology or initial seed, leading a carbonized particles

  12. Numerical Modeling of Tube Forming by HPTR Cold Pilgering Process

    Science.gov (United States)

    Sornin, D.; Pachón-Rodríguez, E. A.; Vanegas-Márquez, E.; Mocellin, K.; Logé, R.

    2016-09-01

    For new fast-neutron sodium-cooled Generation IV nuclear reactors, the candidate cladding materials for the very strong burn-up are ferritic and martensitic oxide dispersion strengthened grades. Classically, the cladding tube is cold formed by a sequence of cold pilger milling passes with intermediate heat treatments. This process acts upon the geometry and the microstructure of the tubes. Consequently, crystallographic texture, grain sizes and morphologies, and tube integrity are highly dependent on the pilgering parameters. In order to optimize the resulting mechanical properties of cold-rolled cladding tubes, it is essential to have a thorough understanding of the pilgering process. Finite Element Method (FEM) models are used for the numerical predictions of this task; however, the accuracy of the numerical predictions depends not only on the type of constitutive laws but also on the quality of the material parameters identification. Therefore, a Chaboche-type law which parameters have been identified on experimental observation of the mechanical behavior of the material is used here. As a complete three-dimensional FEM mechanical analysis of the high-precision tube rolling (HPTR) cold pilgering of tubes could be very expensive, only the evolution of geometry and deformation is addressed in this work. The computed geometry is compared to the experimental one. It is shown that the evolution of the geometry and deformation is not homogeneous over the circumference. Moreover, it is exposed that the strain is nonhomogeneous in the radial, tangential, and axial directions. Finally, it is seen that the dominant deformation mode of a material point evolves during HPTR cold pilgering forming.

  13. Numerical Modeling of Tube Forming by HPTR Cold Pilgering Process

    Science.gov (United States)

    Sornin, D.; Pachón-Rodríguez, E. A.; Vanegas-Márquez, E.; Mocellin, K.; Logé, R.

    2016-07-01

    For new fast-neutron sodium-cooled Generation IV nuclear reactors, the candidate cladding materials for the very strong burn-up are ferritic and martensitic oxide dispersion strengthened grades. Classically, the cladding tube is cold formed by a sequence of cold pilger milling passes with intermediate heat treatments. This process acts upon the geometry and the microstructure of the tubes. Consequently, crystallographic texture, grain sizes and morphologies, and tube integrity are highly dependent on the pilgering parameters. In order to optimize the resulting mechanical properties of cold-rolled cladding tubes, it is essential to have a thorough understanding of the pilgering process. Finite Element Method (FEM) models are used for the numerical predictions of this task; however, the accuracy of the numerical predictions depends not only on the type of constitutive laws but also on the quality of the material parameters identification. Therefore, a Chaboche-type law which parameters have been identified on experimental observation of the mechanical behavior of the material is used here. As a complete three-dimensional FEM mechanical analysis of the high-precision tube rolling (HPTR) cold pilgering of tubes could be very expensive, only the evolution of geometry and deformation is addressed in this work. The computed geometry is compared to the experimental one. It is shown that the evolution of the geometry and deformation is not homogeneous over the circumference. Moreover, it is exposed that the strain is nonhomogeneous in the radial, tangential, and axial directions. Finally, it is seen that the dominant deformation mode of a material point evolves during HPTR cold pilgering forming.

  14. Designing Advanced Ceramic Waste Forms for Electrochemical Processing Salt Waste

    Energy Technology Data Exchange (ETDEWEB)

    Ebert, W. L. [Argonne National Lab. (ANL), Argonne, IL (United States); Snyder, C. T. [Argonne National Lab. (ANL), Argonne, IL (United States); Frank, Steven [Argonne National Lab. (ANL), Argonne, IL (United States); Riley, Brian [Argonne National Lab. (ANL), Argonne, IL (United States)

    2016-03-01

    This report describes the scientific basis underlying the approach being followed to design and develop “advanced” glass-bonded sodalite ceramic waste form (ACWF) materials that can (1) accommodate higher salt waste loadings than the waste form developed in the 1990s for EBR-II waste salt and (2) provide greater flexibility for immobilizing extreme waste salt compositions. This is accomplished by using a binder glass having a much higher Na2O content than glass compositions used previously to provide enough Na+ to react with all of the Cl– in the waste salt and generate the maximum amount of sodalite. The phase compositions and degradation behaviors of prototype ACWF products that were made using five new binder glass formulations and with 11-14 mass% representative LiCl/KCl-based salt waste were evaluated and compared with results of similar tests run with CWF products made using the original binder glass with 8 mass% of the same salt to demonstrate the approach and select a composition for further studies. About twice the amount of sodalite was generated in all ACWF materials and the microstructures and degradation behaviors confirmed our understanding of the reactions occurring during waste form production and the efficacy of the approach. However, the porosities of the resulting ACWF materials were higher than is desired. These results indicate the capacity of these ACWF waste forms to accommodate LiCl/KCl-based salt wastes becomes limited by porosity due to the low glass-to-sodalite volume ratio. Three of the new binder glass compositions were acceptable and there is no benefit to further increasing the Na content as initially planned. Instead, further studies are needed to develop and evaluate alternative production methods to decrease the porosity, such as by increasing the amount of binder glass in the formulation or by processing waste forms in a hot isostatic press. Increasing the amount of binder glass to eliminate porosity will decrease the waste

  15. Optimization of Forming Processes with Different Sheet Metal Alloys

    Science.gov (United States)

    Sousa, Luísa C.; Castro, Catarina F.; António, Carlos C.

    2007-05-01

    Over the past decades relatively heavy components made of steel alloys comprise the majority of many manufactured parts due to steel's low cost, high formability and good strength. The desire to produce lightweight parts has led to studies searching for lighter and stronger materials such as aluminum alloys. However, they exhibit lower elastic stiffness than steel resulting in higher elastic strains causing known distortions such as spring-back and so decreasing accuracy of manufactured net-shape components. This paper presents a developed computational method to optimize the design of sheet metal processes using genetic algorithms. An inverse approach is considered so that the final geometry of the bended blank closely follows a prescribed one. The developed computational method couples a finite element forming simulation and an evolutionary algorithm searching the optimal design parameters of the process. The developed method searches the optimal parameters that ensure a perfect net-shape part. Different aluminum alloys candidates for automotive structural applications are considered and the optimal solutions are analyzed.

  16. Synthesis and characterization of resorcinol-formaldehyde resin chars doped by zinc oxide

    Science.gov (United States)

    Gun'ko, Vladimir M.; Bogatyrov, Viktor M.; Oranska, Olena I.; Urubkov, Iliya V.; Leboda, Roman; Charmas, Barbara; Skubiszewska-Zięba, Jadwiga

    2014-06-01

    Polycondensation polymerization of resorcinol-formaldehyde (RF) mixtures in water with addition of different amounts of zinc acetate and then carbonization of dried gels are studied to prepare ZnO doped chars. Zinc acetate as a catalyst of resorcinol-formaldehyde polycondensation affects structural features of the RF resin (RFR) and, therefore, the texture of chars prepared from Zn-doped RFR. The ZnO doped chars are characterized using thermogravimetry, low temperature nitrogen adsorption/desorption, Raman spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), and high resolution transmission electron microscopy (HRTEM). At a relatively high content of zinc acetate (1 mol per 10-40 mol of resorcinol) in the reaction mixture, the formation of crystallites of ZnO (zincite) occurs in a shape of straight nanorods of 20-130 nm in diameter and 1-3 μm in length. At a small content of zinc acetate (1 mol per 100-500 mol of resorcinol), ZnO in composites is XRD amorphous and does not form individual particles. The ZnO doped chars are pure nanoporous at a minimal ZnO content and nano-mesoporous or nano-meso-macroporous at a higher ZnO content.

  17. Synthesis and characterization of resorcinol–formaldehyde resin chars doped by zinc oxide

    Energy Technology Data Exchange (ETDEWEB)

    Gun’ko, Vladimir M., E-mail: vlad_gunko@ukr.net [Chuiko Institute of Surface Chemistry, 17 General Naumov Street, 03164 Kyiv (Ukraine); Bogatyrov, Viktor M.; Oranska, Olena I. [Chuiko Institute of Surface Chemistry, 17 General Naumov Street, 03164 Kyiv (Ukraine); Urubkov, Iliya V. [Kurdyumov Institute of Metal Physics, 36 Vernadsky Boulevard, 03142 Kyiv (Ukraine); Leboda, Roman; Charmas, Barbara; Skubiszewska-Zięba, Jadwiga [Faculty of Chemistry, Maria Curie-Skłodowska University, 20031 Lublin (Poland)

    2014-06-01

    Polycondensation polymerization of resorcinol–formaldehyde (RF) mixtures in water with addition of different amounts of zinc acetate and then carbonization of dried gels are studied to prepare ZnO doped chars. Zinc acetate as a catalyst of resorcinol–formaldehyde polycondensation affects structural features of the RF resin (RFR) and, therefore, the texture of chars prepared from Zn-doped RFR. The ZnO doped chars are characterized using thermogravimetry, low temperature nitrogen adsorption/desorption, Raman spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), and high resolution transmission electron microscopy (HRTEM). At a relatively high content of zinc acetate (1 mol per 10–40 mol of resorcinol) in the reaction mixture, the formation of crystallites of ZnO (zincite) occurs in a shape of straight nanorods of 20–130 nm in diameter and 1–3 μm in length. At a small content of zinc acetate (1 mol per 100–500 mol of resorcinol), ZnO in composites is XRD amorphous and does not form individual particles. The ZnO doped chars are pure nanoporous at a minimal ZnO content and nano-mesoporous or nano-meso-macroporous at a higher ZnO content.

  18. Trans fatty acid-forming processes in foods: a review

    Directory of Open Access Journals (Sweden)

    Clayton A. Martin

    2007-06-01

    Full Text Available There is a mounting concern about the intake of foods containing trans fatty acids (TFA due to their deleterious effects on human health, mainly on the cardiovascular system. In this way, it is important to consider the processes that form TFA in foods, and the alternatives to minimize them. Among the processes that result in the formation of TFA, the hydrogenation of vegetable oils stands out for its impact on the diet of people living in industrialized countries. Other processes such as edible oil refining, meat irradiation, food frying, and biohydrogenation also contribute to increase the daily intake of TFA.Existe uma crescente preocupação em relação a ingestão elevada de ácidos graxos trans (AGT, devido aos seus efeitos desfavoráveis à saúde, principalmente sobre o sistema cardiovascular. Assim, é importante considerar os processos queoriginam os AGT nos alimentos, e as alternativas para minimizar a sua formação. Entre os processos que resultam na produção de AGT, a hidrogenação de óleos vegetais tem recebido o maior destaque por seu impacto na dieta de pessoas que vivem em países industrializados. Outros processos, como o refino de óleos vegetais, a irradiação de carnes, o preparo de alimentos fritos e a bio-hidrogenação, também contribuem para aumentar a ingestão diária de AGT.

  19. Chasing waterfalls: Experimental controls on knickpoint form and migration processes

    Science.gov (United States)

    Baynes, Edwin; Lague, Dimitri; Attal, Mikael

    2016-04-01

    As the link between the fluvial network and hillslopes, bedrock channels mediate the response of the landscape to changing boundary conditions, such as tectonics and climate. Such signals of transient forcing are manifested in bedrock river profiles through migrating 'knickzones' or 'knickpoints', that separate a downstream reach broadly in equilibrium with the new conditions and an upstream reach which is yet to adjust. Knickpoints therefore mark a dynamic boundary location within mountain landscapes, yet the complexities of the mechanisms of knickpoint retreat are often ignored in studies of landscape evolution. We carried out a series of box flume experiments (65 cm long, 30 cm wide) to explore the importance of knickpoint geometry, mean discharge and substrate strength on the form and migration of knickpoints in a cohesive homogenous substrate. The retreat rate of knickpoints is found to be independent of mean discharge. Knickpoints retreat faster through a weaker substrate. The dominant control on knickpoint retreat, when discharge and substrate strength are constant, is the knickpoint form which is set by the ratio of channel flow depth to knickpoint height. Where the knickpoint height is five times greater than the flow depth, the knickpoints develop undercutting plunge pools, accelerating the removal of material from the knickpoint base and the overall retreat rate, possibly due to the trajectory of the jet at the knickpoint lip. Smaller knickpoints relative to the flow depth are more likely to diffuse from a vertical step into a steepened reach or completely as the knickpoint retreats up channel. These experiments challenge the established assumption in models of landscape evolution that a simple relationship exists between knickpoint retreat rate and discharge/drainage area. In order to fully understand how bedrock channels, and thus mountain landscapes, respond to transient forcing, further detailed study of the mechanics of erosion processes at

  20. Stable carbon isotope changes during artificial charring of propagules

    NARCIS (Netherlands)

    Poole, I.J.; Braadbaart, F.; Boon, J.J.; Bergen, P.F. van

    2002-01-01

    Charred organic remains are ubiquitous in the archaeological and fossil record and are often used to interpret past environments and climate. This study focuses on the physical and chemical alteration that takes place during heating (i.e. charring). Modifications to the internal and external morphol

  1. Gas cleaning with hot char beds studied by stable isotopes

    DEFF Research Database (Denmark)

    Egsgaard, Helge; Ahrenfeldt, Jesper; Ambus, Per;

    2014-01-01

    The chemistry taking place in a high temperature char bed used for binding aromatic tar compounds has been studied in detail. 13C labelled tar compounds were used to trace the incorporation into the char bed using isotope ratio mass spectrometry (IRMS) and GC-MS. Furthermore, compounds labelled...

  2. CHARCOAL PACKED FURNACE FOR LOW-TECH CHARRING OF BONE

    DEFF Research Database (Denmark)

    Jacobsen, P.; Dahi, Elian

    1997-01-01

    A low-tech furnace for charring of raw bone using char coal is developed and tested. The furnace consists of a standard oil drum, fitted with simple materials as available in every market in small towns in developing counties. 80 kg of raw bone and 6 kg of charcoal are used for production of 50 k...

  3. Evaluation of solid fuel char briquettes from human waste.

    Science.gov (United States)

    Ward, Barbara J; Yacob, Tesfayohanes W; Montoya, Lupita D

    2014-08-19

    The developing world faces dual crises of escalating energy demand and lack of urban sanitation infrastructure that pose significant burdens on the environment. This article presents results of a study evaluating the feasibility of using human feces-derived char as a solid fuel for heating and cooking and a potential way to address both crises. The study determined the energy content and the elemental composition of chars pyrolyzed at 300, 450, and 750 °C. Fecal chars made at 300 °C were found to be similar in energy content to wood chars and bituminous coal, having a heating value of 25.6 ± 0.08 MJ/kg, while fecal chars made at 750 °C had an energy content of 13.8 ± 0.48 MJ/kg. The higher heating values of the studied chars were evaluated using their elemental composition and a published predictive model; results found good agreement between the measured and predicted values. Fecal chars made at low temperatures were briquetted with molasses/lime and starch binders. Briquettes made with 10% starch had an average impact resistance index of 79 and a higher heating value of 25 MJ/kg. These values are comparable to those of commercial charcoal briquettes, making fecal char briquettes a potential substitute that also contributes to the preservation of the environment. PMID:25020243

  4. NO Reduction over Biomass and Coal Char during Simultaneous Combustion

    DEFF Research Database (Denmark)

    Zhao, Ke; Glarborg, Peter; Jensen, Anker Degn

    2013-01-01

    This paper reports an experimental study of NO reduction over chars of straw, bark, bituminous coal, and lignite. The experiments were performed in a fixed bed reactor in the temperature range 850–1150 °C. The chars were generated by in situ pyrolysis at the reaction temperature to minimize further...

  5. Physico-chemical characterization of metal-doped bone chars and their adsorption behavior for water defluoridation

    Science.gov (United States)

    Rojas-Mayorga, C. K.; Bonilla-Petriciolet, A.; Silvestre-Albero, J.; Aguayo-Villarreal, I. A.; Mendoza-Castillo, D. I.

    2015-11-01

    New bone chars for fluoride adsorption from drinking water have been synthetized via metallic doping using aluminum and iron salts. A detailed statistical analysis of the metal doping process using the signal-to-noise ratios from Taguchi's experimental designs and its impact on the fluoride adsorption properties of modified bone chars have been performed. The best conditions, including the proper metallic salt, for metal doping were identified to improve the fluoride uptakes of modified bone chars. Results showed that the fluoride adsorption properties of bone chars can be enhanced up to 600% using aluminum sulfate for the surface modification. This aluminum-based adsorbent showed an adsorption capacity of 31 mg/g, which outperformed the fluoride uptakes reported for several adsorbents. Surface interactions involved in the defluoridation process were established using FTIR, DRX and XPS analysis. Defluoridation using the metal-doped bone chars occurred via an ion exchange process between fluoride ions and the hydroxyl groups on the adsorbent surface, whereas the Al(OH)xFy, FexFy, and CaF2 interactions could play also an important role in the removal process. These metal-doped adsorbents anticipate a promising behavior in water treatment, especially in developing countries where the efficiency - cost tradeoff is crucial for implementing new defluoridation technologies.

  6. Cracking of textured zinc coating during forming process

    Energy Technology Data Exchange (ETDEWEB)

    Mei, Z.; Morris, J.W. Jr.

    1993-09-01

    A model is presented to relate cracking of a zinc coating on steel during forming process with its crystallographic texture. There are three deformation modes that can accommodate strains in a zinc coating caused by external loadings; basal slip, twinning, and cleavage cracking. Twinning of a zinc hexagonal crystal induces a contraction along its c-axis while cleavage relaxes tensile strain along its c-axis. Because of this, when basal slip in grains of a textured zinc coating is difficult under a given loading, either twinning or cleavage occurs, depending on whether the basal plane is parallel or normal to the loading axis and whether the loading is tensile or compressive. The loadings during formability or surface friction tests cause twinning in the basal-textured coating and cleavage cracking in the prism-textured coating. The prism-textured coating contains in extraordinarily high hardness since none of the three deformation modes may be operative under compression. These results derived from the model are confirmed with recent studies on electrogalvanized steels.

  7. Form and motion coherence processing in dyspraxia: evidence of a global spatial processing deficit.

    Science.gov (United States)

    O'Brien, Justin; Spencer, Janine; Atkinson, Janette; Braddick, Oliver; Wattam-Bell, John

    2002-08-01

    Form and motion coherence was tested in children with dyspraxia and matched controls to assess their global spatial and global motion processing abilities. Thresholds for detecting form coherence patterns were significantly higher in the dyspraxic group than in the control group. No corresponding difference was found on the motion coherence task. We tested eight children with dyspraxic disorder (mean age 8.2 years) and 50 verbal-mental-age matched controls (mean age 8.4 years) to test for a neural basis to the perceptual abnormalities observed in dyspraxia. The results provide evidence that children with dyspraxia have a specific impairment in the global processing of spatial information. This finding contrasts with other developmental disorders such as Williams syndrome, autism and dyslexia where deficits have been found in global motion processing and not global form processing. We conclude that children with dyspraxia may have a specific occipitotemporal deficit and we argue that testing form and motion coherence thresholds might be a useful diagnostic tool for the often coexistent disorders of dyspraxia and dyslexia. PMID:12167761

  8. The effects of the conditions of char formation on the physical properties of charred phenolic-nylon

    Science.gov (United States)

    Smyly, E. D.; Pears, C. D.

    1972-01-01

    A study was made of the effects of the conditions of char formation on the physical properties of charred phenolic nylon of 0.577 gm/cu cm density. It was found that the thermal conductivity and several of the monitors correlate well with degradation conditions. The monitors included electrical resistivity, sonic velocity, porosity, lattice spacing and crystallite size.

  9. Evolution of Plastic Strain During a Flow Forming Process

    CERN Document Server

    Roy, M J; Wood, J T; 10.1016/j.jmatprotec.2008.03.030

    2011-01-01

    The distribution of equivalent plastic strain through the thickness of several AISI 1020 steel plates formed under different conditions over a smooth cylindrical mandrel using a single-roller forward flow forming operation was studied by measuring the local micro-indentation hardness of the deformed material. The equivalent plastic strain was higher at the inner and outer surfaces and lowest at the center of the workpiece. Empirical expressions are presented which describe the contribution of the roller and mandrel to the total local equivalent plastic strain within the flow formed part. The dependence of these expressions upon the thickness reduction during flow forming is discussed.

  10. Synthesis and Application of a Novel Polyamide Charring Agent for Halogen-Free Flame Retardant Polypropylene

    Directory of Open Access Journals (Sweden)

    Jie Liu

    2013-01-01

    Full Text Available A novel charring agent, poly(p-ethylene terephthalamide (PETA, for halogen-free flame retardant polypropylene was synthesized by using p-phthaloyl chloride (TPC and ethylenediamine through solution polycondensation at low temperature, and the effects of PETA on flame retardance of polypropylene (PP/IFR systems were studied. The experimental results showed that PETA could considerably enhance the fire retardant performance as proved by evidence of the increase of limiting oxygen index (LOI values, the results of UL-94 tests, and cone calorimeter tests (CCT. Fourier transform infrared spectroscopy (FTIR and scanning electron microscope (SEM demonstrated that an appropriate amount of PETA could react with PP/IFR system to form cross-link network; a more compact char layer could be formed which was responsible for the improved thermal and flame retardant properties of PP/IFR systems. However, the superfluous amount of PETA would play the negative role.

  11. Three Dimensional FEM Simulation of Titanium Hollow Blade Forming Process

    NARCIS (Netherlands)

    Zhao Bing, [No Value; Li Zhiqiang, [No Value; Hou Hongliang, [No Value; Liao Jinhua, [No Value; Bai Bingzhe, [No Value

    2010-01-01

    With the introduction of high by-pass turbofan engines into both commercial and military aircraft industries, the fabrication of large size fan blade through superplastic forming/diffusion bonding (SPF/DB) has become a pivotal technique of turbine fan engine. There are three key steps to form a holl

  12. Development and Verification of Enclosure Radiation Capabilities in the CHarring Ablator Response (CHAR) Code

    Science.gov (United States)

    Salazar, Giovanni; Droba, Justin C.; Oliver, Brandon; Amar, Adam J.

    2016-01-01

    With the recent development of multi-dimensional thermal protection system (TPS) material response codes, the capability to account for surface-to-surface radiation exchange in complex geometries is critical. This paper presents recent efforts to implement such capabilities in the CHarring Ablator Response (CHAR) code developed at NASA's Johnson Space Center. This work also describes the different numerical methods implemented in the code to compute geometric view factors for radiation problems involving multiple surfaces. Verification of the code's radiation capabilities and results of a code-to-code comparison are presented. Finally, a demonstration case of a two-dimensional ablating cavity with enclosure radiation accounting for a changing geometry is shown.

  13. Preliminary evaluation of alternative waste form solidification processes. Volume II. Evaluation of the processes

    Energy Technology Data Exchange (ETDEWEB)

    1980-08-01

    This Volume II presents engineering feasibility evaluations of the eleven processes for solidification of nuclear high-level liquid wastes (HHLW) described in Volume I of this report. Each evaluation was based in a systematic assessment of the process in respect to six principal evaluation criteria: complexity of process; state of development; safety; process requirements; development work required; and facility requirements. The principal criteria were further subdivided into a total of 22 subcriteria, each of which was assigned a weight. Each process was then assigned a figure of merit, on a scale of 1 to 10, for each of the subcriteria. A total rating was obtained for each process by summing the products of the subcriteria ratings and the subcriteria weights. The evaluations were based on the process descriptions presented in Volume I of this report, supplemented by information obtained from the literature, including publications by the originators of the various processes. Waste form properties were, in general, not evaluated. This document describes the approach which was taken, the developent and application of the rating criteria and subcriteria, and the evaluation results. A series of appendices set forth summary descriptions of the processes and the ratings, together with the complete numerical ratings assigned; two appendices present further technical details on the rating process.

  14. Preliminary evaluation of alternative waste form solidification processes. Volume II. Evaluation of the processes

    International Nuclear Information System (INIS)

    This Volume II presents engineering feasibility evaluations of the eleven processes for solidification of nuclear high-level liquid wastes (HHLW) described in Volume I of this report. Each evaluation was based in a systematic assessment of the process in respect to six principal evaluation criteria: complexity of process; state of development; safety; process requirements; development work required; and facility requirements. The principal criteria were further subdivided into a total of 22 subcriteria, each of which was assigned a weight. Each process was then assigned a figure of merit, on a scale of 1 to 10, for each of the subcriteria. A total rating was obtained for each process by summing the products of the subcriteria ratings and the subcriteria weights. The evaluations were based on the process descriptions presented in Volume I of this report, supplemented by information obtained from the literature, including publications by the originators of the various processes. Waste form properties were, in general, not evaluated. This document describes the approach which was taken, the developent and application of the rating criteria and subcriteria, and the evaluation results. A series of appendices set forth summary descriptions of the processes and the ratings, together with the complete numerical ratings assigned; two appendices present further technical details on the rating process

  15. Preparation of mulberry branch biomass char and its usage in wastewater treatment.

    Science.gov (United States)

    Wu, Dong Lei; Wang, Wei; Zhang, Jing Hui; Fu, Hao; Lv, Xiao Shu; Xu, Xin Hua

    2012-11-01

    Biomass char was prepared from mulberry branches by physical activation. An examination by Fourier transform infrared spectroscopy (FTIR) indicated that the functional groups of Si-O were mostly burnt out, significantly decreasing the ash content Analysis of data from a scanning electron microscope (SEM) and a Brunauer-Emmett-Teller (BET) test also revealed increased surface roughness and pore structure, which improved the adsorption capacity of biomass char after preparation. The optimum conditions for preparation were found to be pyrolysis at 700 degrees C for 30 minutes, and then activation at 750 degrees C for one hour, with 3.4% steam content for the activating agent. The prepared biomass char was then employed to adsorb ammonium, copper(II) actetate [Cu(II)] and hexavalent chromium [Cr(VI)] in a solution. The results indicated that the prepared biomass char had a better adsorptive performance than the raw material. Moreover, the removal of determinands increased along with the dosage, and the highest adsorption efficiency of ammonium, copper(II) acetate [Cu(II)] and hexavalent chromium [Cr(VI)] were found to be 20%, 100% and 50%, respectively. The adsorptions of ammonium and hexavalent chromium [Cr(VI)] can be simulated by a pseudo-second order model, while the adsorption of copper(II) acetate [Cu(II)] is better simulated by a pseudo-first order model. The adsorption isotherms of copper(II) acetate [Cu(II)] by biomass char were also investigated, and the Langmuir isotherm was found to best describe the adsorption process. PMID:23356022

  16. The role of nano-sized manganese coatings on bone char in removing arsenic(V) from solution: Implications for permeable reactive barrier technologies.

    Science.gov (United States)

    Liu, Jing; He, Lile; Dong, Faqin; Hudson-Edwards, Karen A

    2016-06-01

    Although the removal of arsenic(V) (As(V)) from solution can be improved by forming metal-bearing coatings on solid media, there has been no research to date examining the relationship between the coating and As(V) sorption performance. Manganese-coated bone char samples with varying concentrations of Mn were created to investigate the adsorption and desorption of As(V) using batch and column experiments. Breakthrough curves were obtained by fitting the Convection-Diffusion Equation (CDE), and retardation factors were used to quantify the effects of the Mn coatings on the retention of As(V). Uncoated bone char has a higher retention factor (44.7) than bone char with 0.465 mg/g of Mn (22.0), but bone char samples with between 5.02 mg/g and 14.5 mg/g Mn have significantly higher retention factors (56.8-246). The relationship between retardation factor (Y) and Mn concentration (X) is Y = 15.1 X + 19.8. Between 0.2% and 0.6% of the sorbed As is desorbed from the Mn-coated bone char at an initial pH value of 4, compared to 30% from the uncoated bone char. The ability of the Mn-coated bone char to neutralize solutions increases with increased amounts of Mn on the char. The results suggest that using Mn-coated bone char in Permeable Reactive Barriers would be an effective method for remediating As(V)-bearing solutions such as acid mine drainage.

  17. A Study on the Applicability of Kinetic Models for Shenfu Coal Char Gasification with CO2 at Elevated Temperatures

    Directory of Open Access Journals (Sweden)

    Jinsheng Gao

    2009-07-01

    Full Text Available In this paper, measurements of the CO2 gasification kinetics for two types of Shenfu coal chars, which were respectively prepared by slow and rapid pyrolysis at temperatures of 950 °C and 1,400 °C, were performed by an isothermal thermo-gravimetric analysis under ambient pressure and elevated temperature conditions. Simultaneously, the applicability of the kinetic model for the CO2 gasification reaction of Shenfu coal chars was discussed. The results showed: (i the shrinking un-reacted core model was not appropriate to describe the gasification reaction process of Shenfu coal chars with CO2 in the whole experimental temperature range; (ii at the relatively low temperatures, the modified volumetric model was as good as the random pore model to simulate the CO2 gasification reaction of Shenfu coal chars, while at the elevated temperatures, the modified volumetric model was superior to the random pore model for this process; (iii the integral expression of the modified volumetric model was more favorable than the differential expression of that for fitting the experimental data. Moreover, by simply introducing a function: A = A★exp(ft, it was found that the extensive model of the modified volumetric model could make much better predictions than the modified volumetric model. It was recommended as a convenient empirical model for comprehensive simulation of Shenfu coal char gasification with under conditions close to those of entrained flow gasification.

  18. Structure of Block Copolymer Hydrogel Formed by Complex Coacervate Process

    Science.gov (United States)

    Choi, Soohyung; Ortony, Julia; Krogstad, Daniel; Spruell, Jason; Lynd, Nathaniel; Han, Songi; Kramer, Edward

    2012-02-01

    Complex coacervation occurs when oppositely charged polyelectrolytes associate in solution, forming dense micron-sized droplets. Hydrogels with coacervate block domains were formed by mixing two ABA and A'BA' triblock copolymer solutions in water where the A and A' blocks are oppositely charged. Small-angle neutron scattering (SANS) was used to investigate the structure of hydrogels formed by ABA triblock copolymers (A block: poly(allyl glycidyl ether) functionalized with guanidinium (A) or sulfonate (A'), B block: poly(ethylene oxide)). By using an appropriate fitting model, structural information such as coacervate core block radius and water volume fraction w can be extracted from SANS data. The results reveal that w in the coacervate core block was significantly higher than in conventional triblock copolymer hydrogels where microphase separation is driven by the hydrophobicity of the core-forming blocks.

  19. A burnout prediction model based around char morphology

    Energy Technology Data Exchange (ETDEWEB)

    Tao Wu; Edward Lester; Michael Cloke [University of Nottingham, Nottingham (United Kingdom). School of Chemical, Environmental and Mining Engineering

    2006-05-15

    Several combustion models have been developed that can make predictions about coal burnout and burnout potential. Most of these kinetic models require standard parameters such as volatile content and particle size to make a burnout prediction. This article presents a new model called the char burnout (ChB) model, which also uses detailed information about char morphology in its prediction. The input data to the model is based on information derived from two different image analysis techniques. One technique generates characterization data from real char samples, and the other predicts char types based on characterization data from image analysis of coal particles. The pyrolyzed chars in this study were created in a drop tube furnace operating at 1300{sup o}C, 200 ms, and 1% oxygen. Modeling results were compared with a different carbon burnout kinetic model as well as the actual burnout data from refiring the same chars in a drop tube furnace operating at 1300{sup o}C, 5% oxygen, and residence times of 200, 400, and 600 ms. A good agreement between ChB model and experimental data indicates that the inclusion of char morphology in combustion models could well improve model predictions. 38 refs., 5 figs., 6 tabs.

  20. Feedback processes in cellulose thermal decomposition. Implications for fire-retarding strategies and treatments

    CERN Document Server

    Ball, R; Brindley, J

    2002-01-01

    A simple dynamical system that models the competitive thermokinetics and chemistry of cellulose decomposition is examined, with reference to evidence from experimental studies indicating that char formation is a low activation energy exothermal process and volatilization is a high activation energy endothermal process. The thermohydrolysis chemistry at the core of the primary competition is described. Essentially, the competition is between two nucleophiles, a molecule of water and an -OH group on C_6 of an end glucosyl cation, to form either a reducing chain fragment with the propensity to undergo the bond-forming reactions that ultimately form char or a levoglucosan-end-fragment that depolymerizes to volatile products. The results of this analysis suggest that promotion of char formation under thermal stress can actually increase the production of flammable volatiles. Thus we would like to convey an important safety message in this paper: in some situations where heat and mass transfer is restricted in cell...

  1. Structural and Compositional Transformations of Biomass Chars during Fast Pyrolysis

    DEFF Research Database (Denmark)

    Trubetskaya, Anna; Steibel, Markus; Spliethoff, Hartmut;

    In this work the physical and chemical transformations of biomass chars during fast pyrolysis, considered as a 2nd stage of combustion, has been investigated. Seven biomasses containing different amount of ash and organic components were reacted at up to 1673 K with high heating rates in a wire......-mesh reactor and the resulting chars were retrieved. In order to obtain information on the structural and compositional transformations of the biomass chars, samples were subjected to elemental analysis, scanning electron microcopy with EDX and Raman spectrometry. The results show that there are significant...

  2. Process for forming a metal compound coating on a substrate

    International Nuclear Information System (INIS)

    This patent describes a method of coating a substrate with a thin layer of a metal compound by forming a dispersion of an electrophoretically active organic colloid and a precursor of the metal compound in an electrolytic cell in which the substrate is an electrode. Upon application of an electric potential, the electrode is coated with a mixture of the organic colloid and the precursor to the metal compound, and the coated substrate is then heated in the presence of an atmosphere or vacuum to decompose the organic colloid and form a coating of either a combination of metal compound and carbon, or optionally forming a porous metal compound coating by heating to a temperature high enough to chemically react the carbon

  3. Process for forming a metal compound coating on a substrate

    Science.gov (United States)

    Sharp, D.J.; Vernon, M.E.; Wright, S.A.

    1988-06-29

    A method of coating a substrate with a thin layer of a metal compound by forming a dispersion of an electrophoretically active organic colloid and a precursor of the metal compound in an electrolytic cell in which the substrate is an electrode. Upon application of an electric potential, the electrode is coated with a mixture of the organic colloid and the precursor to the metal compound, and the coated substrate is then heated in the presence of an atmosphere or vacuum to decompose the organic colloid and form a coating of either a combination of metal compound and carbon, or optionally forming a porous metal compound coating by heating to a temperature high enough to chemically react the carbon.

  4. Determination of the intrinsic reactivities for carbon dioxide gasification of rice husk chars through using random pore model.

    Science.gov (United States)

    Gao, Xiaoyan; Zhang, Yaning; Li, Bingxi; Zhao, Yijun; Jiang, Baocheng

    2016-10-01

    Rice husk is abundantly available and environmentally friendly, and char-CO2 gasification is of great importance for the biomass gasification process. The intrinsic reaction rates of carbon dioxide gasification with rice husk chars derived from different pyrolysis temperatures were investigated in this study by conducting thermogravimetric analysis (TGA) measurements. The effects of gasification temperature and reactant partial pressure on the char-CO2 gasification were investigated and the random pore model (RPM) was used to determine the intrinsic kinetic parameters based on the experimental data. The results obtained from this study show that the activation energy, reaction order and pre-exponential factor varied in the ranges of 226.65-232.28kJ/mol, 0.288-0.346 and 2.38×10(5)-2.82×10(5)1/sPa(n) for the rice husk chars pyrolyzed at 700-900°C, respectively. All the determination coefficients between the RPM predictions and experimental results were higher than 0.906, indicating the RPM is reliable for determining and evaluating the intrinsic reactivities of rice husk chars. PMID:27459684

  5. A lubrication approach to friction in thermoplastic composites forming processes

    NARCIS (Netherlands)

    Thije, ten R.H.W.; Akkerman, R.; Ubbink, M.P.; Meer, van der L.

    2011-01-01

    Friction is an important phenomenon that can dominate the resulting product geometry of thermoplastic composites upon forming. A model was developed that predicts the friction between a thermoplastic laminate and a rigid tool. The model is based on the Reynolds equation for thin film lubrication and

  6. Status of plutonium ceramic immobilization processes and immobilization forms

    Energy Technology Data Exchange (ETDEWEB)

    Ebbinghaus, B.B.; Van Konynenburg, R.A. [Lawrence Livermore National Lab., CA (United States); Vance, E.R.; Jostsons, A. [Australian Nuclear Science and Technology Organization, Menai (Australia)] [and others

    1996-05-01

    Immobilization in a ceramic followed by permanent emplacement in a repository or borehole is one of the alternatives currently being considered by the Fissile Materials Disposition Program for the ultimate disposal of excess weapons-grade plutonium. To make Pu recovery more difficult, radioactive cesium may also be incorporated into the immobilization form. Valuable data are already available for ceramics form R&D efforts to immobilize high-level and mixed wastes. Ceramics have a high capacity for actinides, cesium, and some neutron absorbers. A unique characteristic of ceramics is the existence of mineral analogues found in nature that have demonstrated actinide immobilization over geologic time periods. The ceramic form currently being considered for plutonium disposition is a synthetic rock (SYNROC) material composed primarily of zirconolite (CaZrTi{sub 2}O{sub 7}), the desired actinide host phase, with lesser amounts of hollandite (BaAl{sub 2}Ti{sub 6}O{sub 16}) and rutile (TiO{sub 2}). Alternative actinide host phases are also being considered. These include pyrochlore (Gd{sub 2}Ti{sub 2}O{sub 7}), zircon (ZrSiO{sub 4}), and monazite (CePO{sub 4}), to name a few of the most promising. R&D activities to address important technical issues are discussed. Primarily these include moderate scale hot press fabrications with plutonium, direct loading of PuO{sub 2} powder, cold press and sinter fabrication methods, and immobilization form formulation issues.

  7. Finite element simulations of laminated composite forming processes

    NARCIS (Netherlands)

    Thije, ten René Hermanus Willem

    2007-01-01

    Continuous Fibre Reinforced Polymers (CFRPs) combine strength and stiffness of fibres with the design flexibility of polymeric matrix materials. Fast production methods like thermo-folding, diaphragm forming or stamping can produce large numbers of CFRP components in a cost efficient way. Pre-consol

  8. CHAR CRYSTALLINE TRANSFORMATIONS DURING COAL COMBUSTION AND THEIR IMPLICATIONS FOR CARBON BURNOUT

    Energy Technology Data Exchange (ETDEWEB)

    ROBERT H. HURT

    1998-09-08

    temperatures approaching 3000 o C. For the measurement of temperature histories an optical diagnostic is being developed that offers sufficient spatial resolution to distinguish the sample temperature from the substrate temperature. The optical diagnostic is based on a CID camera, a high-power lens, and movable mirrors to projecting multiple, filtered images onto a single chip. Oxidation kinetics are measured on the heat treated samples by a nonisothermal TGA technique. Task 2 Thermal deactivation kinetics. The goal of this task is to quantify thermal char deactivation as a function of temperature history and parent coal, with an emphasis on inert environments at temperatures and times found in combustion systems. The results are to be cast in the form of deactivation kinetics useful for incorporation in combustion models. Task 3 Crystal structure characterization. Crystal structure characterization provides important insight into the mechanisms of thermal char deactivation, and the degree of crystalline transformations has shown a strong correlation with reactivity changes in recent combustion studies [Davis et al., 1992, Beeley et al., 1996]. This task seeks to improve our understanding of char carbon crystalline transformations under combustion conditions by analyzing a large set of HRTEM fringe images for a series of flame-generated chars whose reactivities have been previously reported [Hurt et al., 1995, Beeley et al., 1996]. As a first step, a new technique is being developed for the quantitative analysis of fringe images, extending previous work to allow measurement of a complete set of crystal structure parameters including mean layer size, mean stacking height, interlayer spacing, layer curvature, amorphous fraction, and degree of anisotropy. The resulting database will revealing, at a very fundamental level, the basic differences in char crystal structure due to parent coal rank and to temperature history in the range of interest to combustion systems.

  9. Study on CO2 gasification reactivity and physical characteristics of biomass, petroleum coke and coal chars.

    Science.gov (United States)

    Huo, Wei; Zhou, Zhijie; Chen, Xueli; Dai, Zhenghua; Yu, Guangsuo

    2014-05-01

    Gasification reactivities of six different carbonaceous material chars with CO2 were determined by a Thermogravimetric Analyzer (TGA). Gasification reactivities of biomass chars are higher than those of coke and coal chars. In addition, physical structures and chemical components of these chars were systematically tested. It is found that the crystalline structure is an important factor to evaluate gasification reactivities of different chars and the crystalline structures of biomass chars are less order than those of coke and coal chars. Moreover, initial gasification rates of these chars were measured at high temperatures and with relatively large particle sizes. The method of calculating the effectiveness factor η was used to quantify the effect of pore diffusion on gasification. The results show that differences in pore diffusion effects among gasification with various chars are prominent and can be attributed to different intrinsic gasification reactivities and physical characteristics of different chars. PMID:24642484

  10. Morphology and reactivity characteristics of char biomass particles.

    Science.gov (United States)

    Avila, Claudio; Pang, Cheng Heng; Wu, Tao; Lester, Ed

    2011-04-01

    In this work, 10 different biomasses were selected which included directly grown energy crops, industrial waste material and different wood types. Each biomass was sieved into six different size fractions and pyrolysed in a fixed bed furnace preheated to 1000 °C to produce a char residue. Intrinsic reactivity during burnout was measured using a non-isothermal thermogravimetric method. Scanning electron microscopy and oil immersion microscopy were used to characterise the morphology of the products. Char morphology was summarised in terms of degree of deformation, internal particle structure and wall thickness. Intrinsic reactivity corresponded directly with these morphology groupings showing a significant correlation between char morphotypes, char reactivity and the initial biomass material. PMID:21334876

  11. Thermal analysis of charring materials based on pyrolysis interface model

    Directory of Open Access Journals (Sweden)

    Huang Hai-Ming

    2014-01-01

    Full Text Available Charring thermal protection systems have been used to protect hypersonic vehicles from high heat loads. The pyrolysis of charring materials is a complicated physical and chemical phenomenon. Based on the pyrolysis interface model, a simulating approach for charring ablation has been designed in order to obtain one dimensional transient thermal behavior of homogeneous charring materials in reentry capsules. As the numerical results indicate, the pyrolysis rate and the surface temperature under a given heat flux rise abruptly in the beginning, then reach a plateau, but the temperature at the bottom rises very slowly to prevent the structural materials from being heated seriously. Pyrolysis mechanism can play an important role in thermal protection systems subjected to serious aerodynamic heat.

  12. CO II laser free-form processing of hard tissue

    Science.gov (United States)

    Werner, Martin; Klasing, Manfred; Ivanenko, Mikhail; Harbecke, Daniela; Steigerwald, Hendrik; Hering, Peter

    2007-07-01

    Drilling and surface processing of bone and tooth tissue belongs to standard medical procedures (bores and embeddings for implants, trepanation etc.). Small circular bores can be generally quickly produced with mechanical drills. However problems arise at angled drilling, the need to execute drilling procedures without damaging of sensitive soft tissue structures underneath the bone or the attempt to mill small non-circular cavities in hard tissue with high precision. We present investigations on laser hard tissue "milling", which can be advantageous for solving these problems. The processing of bone is done with a CO II laser (10.6 μm) with pulse durations of 50 - 100 μs, combined with a PC-controlled fast galvanic laser beam scanner and a fine water-spray, which helps keeping the ablation process effective and without thermal side-effects. Laser "milling" of non-circular cavities with 1 - 4 mm width and about 10 mm depth can be especially interesting for dental implantology. In ex-vivo investigations we found conditions for fast laser processing of these cavities without thermal damage and with minimised tapering. It included the exploration of different filling patterns (concentric rings, crosshatch, parallel lines, etc.), definition of maximal pulse duration, repetition rate and laser power, and optimal water spray position. The optimised results give evidence for the applicability of pulsed CO II lasers for biologically tolerable effective processing of deep cavities in hard tissue.

  13. Complex life forms may arise from electrical processes

    Directory of Open Access Journals (Sweden)

    Elson Edward C

    2010-06-01

    Full Text Available Abstract There is still not an appealing and testable model to explain how single-celled organisms, usually following fusion of male and female gametes, proceed to grow and evolve into multi-cellular, complexly differentiated systems, a particular species following virtually an invariant and unique growth pattern. An intrinsic electrical oscillator, resembling the cardiac pacemaker, may explain the process. Highly auto-correlated, it could live independently of ordinary thermodynamic processes which mandate increasing disorder, and could coordinate growth and differentiation of organ anlage.

  14. Hydrogen inhibition in steam gasification of annealed Saran char

    Science.gov (United States)

    Lussier, Michael Gerard, Jr.

    1998-12-01

    Annealed Saran and coal chars were gasified in mixtures of H2O/H 2/Ar at 1123 K and varying pressures to varying extents of conversion, followed by transient kinetic desorption and TPD to 1773 K, in order to characterize hydrogen adsorbed onto char surfaces during gasification and to identify the mode(s) of hydrogen inhibition at varying extents of char conversion. Adsorbed hydrogen concentration on annealed Saran char was found to be independent of reactant gas composition and pressure, to increase from an initial surface concentration of 3 x 10-5 to 1.5 x 10 -3 0--3 mmolH2(STP)/m2 over the first 1% conversion, and to increase very gradually after this. Gasification rate declines significantly over the initial 1% carbon conversion and is inhibited mainly by dissociative hydrogen adsorption over this range. Linearized Langmiur-Hinshellwood type rate expressions based on the three primary modes of hydrogen inhibition have been developed for all gasification data above 1% char conversion. The expression which indicates reverse oxygen exchange or "associative" hydrogen adsorption fits the data well, while the expression for dissociative hydrogen adsorption does not. Calculation of the equilibrium constant for oxygen exchange (k1/k-1 = 0.029) indicates a low fractional coverage of adsorbed oxygen complexes (C(O)), while the equilibrium constant for "associative" hydrogen adsorption (k3/k-3 = 425 MPa-1) stipulates a high fractional coverage of "associatively" adsorbed hydrogen. Because no "associatively" bound hydrogen was detected and because low concentrations of surface oxides were found during gasification, it is concluded that reverse oxygen exchange is the primary mode of hydrogen inhibition past 1% char conversion for Saran char. Active site propagation along graphitic zig-zag edges is proposed as the main source of surface carbon consumption for steady-state char gasification in steam.

  15. Separation of isoflavones form okara : process mechanisms & synthesis

    NARCIS (Netherlands)

    Jankowiak, L.

    2014-01-01

    By-product utilisation, more efficient use of resources, and more sustainable processing have become of the utmost importance for society and the food industry. During soymilk production, a by-product called okara is produced in great quantities. Despite being a by-product, okara contains many nutri

  16. Process of forming a sol-gel/metal hydride composite

    Science.gov (United States)

    Congdon, James W.

    2009-03-17

    An external gelation process is described which produces granules of metal hydride particles contained within a sol-gel matrix. The resulting granules are dimensionally stable and are useful for applications such as hydrogen separation and hydrogen purification. An additional coating technique for strengthening the granules is also provided.

  17. Ferrolysis, a soil-forming process in hydromorphic conditions

    NARCIS (Netherlands)

    Brinkman, R.

    1979-01-01

    A hypothesis was proposed explaining clay decomposition and interlayering in acid, seasonally wet soils, under the influence of the periodic reduction and oxidation of iron. This process, termed ferrolysis, is as follows. In the wet season, reduction of ferric oxides produces dissolved ferrous iron

  18. Process considerations for hot pressing ceramic nuclear waste forms

    International Nuclear Information System (INIS)

    Spray calcined simulated ceramic nuclear waste powders were hot pressed in graphite, nickel-lined graphite and ZrO2-lined Al2O3 dies. Densification, initial off-gas, waste element retention and pellet-die interactions were evaluated. Indicated process considerations and limitations are discussed. 15 figures

  19. Tool And Blank Interaction In The Cross-Die Forming Process

    NARCIS (Netherlands)

    Lingbeek, R.A.; Meinders, T.; Rietman, A.

    2008-01-01

    The deformation of the press and the forming tools during a deep drawing process is small. However, it has a significant influence on the formed product, since the draw-in is affected significantly by this deformation. This effect is demonstrated for the cross-die forming process. The process was si

  20. Processes to remove acid forming gases from exhaust gases

    Energy Technology Data Exchange (ETDEWEB)

    Chang, S.G.

    1994-09-20

    The present invention relates to a process for reducing the concentration of NO in a gas, which process comprises: (A) contacting a gas sample containing NO with a gaseous oxidizing agent to oxidize the NO to NO[sub 2]; (B) contacting the gas sample of step (A) comprising NO[sub 2] with an aqueous reagent of bisulfite/sulfite and a compound selected from urea, sulfamic acid, hydrazinium ion, hydrazoic acid, nitroaniline, sulfanilamide, sulfanilic acid, mercaptopropanoic acid, mercaptosuccinic acid, cysteine or combinations thereof at between about 0 and 100 C at a pH of between about 1 and 7 for between about 0.01 and 60 sec; and (C) optionally contacting the reaction product of step (A) with conventional chemical reagents to reduce the concentrations of the organic products of the reaction in step (B) to environmentally acceptable levels. Urea or sulfamic acid are preferred, especially sulfamic acid, and step (C) is not necessary or performed. 16 figs.

  1. Separation of isoflavones form okara : process mechanisms & synthesis

    OpenAIRE

    Jankowiak, L

    2014-01-01

    By-product utilisation, more efficient use of resources, and more sustainable processing have become of the utmost importance for society and the food industry. During soymilk production, a by-product called okara is produced in great quantities. Despite being a by-product, okara contains many nutrients, which could be utilised for human consumption. Isoflavones are one example of the components present in soy, which are also found in okara. Isoflavones are a subclass of flavonoids, a group o...

  2. The effects of forming parameters on conical ring rolling process.

    Science.gov (United States)

    Meng, Wen; Zhao, Guoqun; Guan, Yanjin

    2014-01-01

    The plastic penetration condition and biting-in condition of a radial conical ring rolling process with a closed die structure on the top and bottom of driven roll, simplified as RCRRCDS, were established. The reasonable value range of mandrel feed rate in rolling process was deduced. A coupled thermomechanical 3D FE model of RCRRCDS process was established. The changing laws of equivalent plastic strain (PEEQ) and temperature distributions with rolling time were investigated. The effects of ring's outer radius growth rate and rolls sizes on the uniformities of PEEQ and temperature distributions, average rolling force, and average rolling moment were studied. The results indicate that the PEEQ at the inner layer and outer layer of rolled ring are larger than that at the middle layer of ring; the temperatures at the "obtuse angle zone" of ring's cross-section are higher than those at "acute angle zone"; the temperature at the central part of ring is higher than that at the middle part of ring's outer surfaces. As the ring's outer radius growth rate increases at its reasonable value ranges, the uniformities of PEEQ and temperature distributions increase. Finally, the optimal values of the ring's outer radius growth rate and rolls sizes were obtained.

  3. The Effects of Forming Parameters on Conical Ring Rolling Process

    Directory of Open Access Journals (Sweden)

    Wen Meng

    2014-01-01

    Full Text Available The plastic penetration condition and biting-in condition of a radial conical ring rolling process with a closed die structure on the top and bottom of driven roll, simplified as RCRRCDS, were established. The reasonable value range of mandrel feed rate in rolling process was deduced. A coupled thermomechanical 3D FE model of RCRRCDS process was established. The changing laws of equivalent plastic strain (PEEQ and temperature distributions with rolling time were investigated. The effects of ring’s outer radius growth rate and rolls sizes on the uniformities of PEEQ and temperature distributions, average rolling force, and average rolling moment were studied. The results indicate that the PEEQ at the inner layer and outer layer of rolled ring are larger than that at the middle layer of ring; the temperatures at the “obtuse angle zone” of ring’s cross-section are higher than those at “acute angle zone”; the temperature at the central part of ring is higher than that at the middle part of ring’s outer surfaces. As the ring’s outer radius growth rate increases at its reasonable value ranges, the uniformities of PEEQ and temperature distributions increase. Finally, the optimal values of the ring’s outer radius growth rate and rolls sizes were obtained.

  4. Time resolved quantitative imaging of charring in materials at temperatures above 1000 K

    Science.gov (United States)

    Böhrk, Hannah; Jemmali, Raouf

    2016-07-01

    A device is presented allowing for in situ investigation of chemically changing materials by means of X-ray imaging. A representative cork ablator sample, additionally instrumented with thermocouples, is encapsulated in an evacuated cell heating a sample surface with a heat flux of 230 kW/m2. The images show the sample surface and the in-depth progression of the char front dividing the char layer from the virgin material. Correlating the images to thermocouple data allows for the deduction of a reaction temperature. For the representative cork ablator investigated at the present conditions, the progression rate of the pyrolysis layer is determined to 0.0285 mm/s and pyrolysis temperature is 770 or 737 K, depending on the pre-existing conditions. It is found that the novel device is ideally suited for volume process imaging.

  5. Process of forming catalytic surfaces for wet oxidation reactions

    Science.gov (United States)

    Jagow, R. B. (Inventor)

    1977-01-01

    A wet oxidation process was developed for oxidizing waste materials, comprising dissolved ruthenium salt in a reactant feed stream containing the waste materials. The feed stream is introduced into a reactor, and the reactor contents are then raised to an elevated temperature to effect deposition of a catalytic surface of ruthenium black on the interior walls of the reactor. The feed stream is then maintained in the reactor for a period of time sufficient to effect at least partial oxidation of the waste materials.

  6. Method for processing ENDF/B photon form factor data

    International Nuclear Information System (INIS)

    A method is described for processing ENDF/B photon data to generate group-to-group scattering matrices. The method has these salient features: 1. It is tailored toward treating the full energy and angular detail with which the cross sections are represented in ENDF/B; 2. It is simple to program; 3. It closely parallels a treatment developed for producing multigroup neutron matrices; 4. The time required to execute the method on a computer varies linearly with the number of energy groups as opposed to double numerical integration schemes which tend to vary as the square of the number of groups

  7. Friction Modelling In Connection With Cold Forming Processes

    DEFF Research Database (Denmark)

    Tan, Xincai

    is first coated with aluminate conversion coatings and then lubricated by alkaline soap, molybdenum disulphide (MoS2), alkaline soap followed by molykote grease paste, or kerosene respectively. Steel and stainless steel are first coated with zinc phosphate coatings and then lubricated by either alkaline...... soap or molybdenum disulphide. As processes testing friction sensitive flow, the ring-compression tests and the double cup extrusion tests are carried out. An absolute constant friction model has been proposed to separate the influence of strain hardening from friction. This model has been applied...

  8. Optimization of Stamp Forming Process for Thermoplastic Composites

    Directory of Open Access Journals (Sweden)

    Chih-Min Ma

    2014-02-01

    Full Text Available The present study is focused on the development of a two-dimensional stamping method for the manufacturing of fiber reinforced composites with thermoplastic matrix resins. Materials investigated are carbon fiber reinforced polyamide-6. Taguchi L16 orthogonal array is used in split-plot designs. The processing conditions include thermoforming temperature, mold temperature, pressure and time, required to establish high-quality parts. From the experimental results, we derive a set of best combination, A1 (90°, B2 (263C, C1 (105C, D1 (33 kg/cm2 and E2 (48 sec and carry out an estimated equation for the short-beam shear strength. The results have described the correlations between processing parameters and shear stress. Finally, for verifying the prediction ability of the estimated equation, the confirmation experiments are conducted. The confirmation test result is 48.67 kg/mm2, fall in the confidence interval. It shows that the prediction ability of estimated equation and the repetition of the experimental results has confirmed and accepted by the tests.

  9. Processes to remove acid forming gases from exhaust gases

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Shih-Ger (El Cerrito, CA)

    1994-01-01

    The present invention relates to a process for reducing the concentration of NO in a gas, which process comprises: (A) contacting a gas sample containing NO with a gaseous oxidizing agent to oxidize the NO to NO.sub.2 ; (B) contacting the gas sample of step (A) comprising NO.sub.2 with an aqueous reagent of bisulfite/sulfite and a compound selected from urea, sulfamic acid, hydrazinium ion, hydrazoic acid, nitroaniline, sulfanilamide, sulfanilic acid, mercaptopropanoic acid, mercaptosuccinic acid, cysteine or combinations thereof at between about 0.degree. and 100.degree. C. at a pH of between about 1 and 7 for between about 0.01 and 60 sec; and (C) optionally contacting the reaction product of step (A) with conventional chemical reagents to reduce the concentrations of the organic products of the reaction in step (B) to environ-mentally acceptable levels. Urea or sulfamic acid are preferred, especially sulfamic acid, and step (C) is not necessary or performed.

  10. Bio-oil and bio-char production from biomass and their structural analyses

    International Nuclear Information System (INIS)

    Energy demand is increasing day by day because of the rapid developments in the population, industrialization and urbanisation. Since, fossil fuels will be at the verge of getting extinct, researches are mostly focused on the renewable sources, such as biomass, in recent years. This paper provides an environmentally friendly process to convert waste biomass samples to bio-oil and bio-char by pyrolysis. For this purpose, pyrolysis characteristics of pomegranate peels under inert atmosphere were studied by using both TGA to analysis decomposition behaviour and a batch reactor to investigate product yields and properties. The properties of bio-oil and bio-char were investigated by different analytical techniques such as GC-MS, FT-IR, SEM, He pycnometry and elemental analysis. As a consequence, it is possible to obtain bio-oil, which has similar properties like petroleum hydrocarbons, and to obtain bio-char, which can be further used as a solid fuel or a carbonaceous adsorbent material via pyrolysis process. (full text)

  11. Caracterization of the process of forming strategic alliances

    Directory of Open Access Journals (Sweden)

    Luciano Mattana

    2009-03-01

    Full Text Available The union between companies has represented an increase in their competitive capabilities. The strategic alliances have been shown as alternatives for the adequacy of the conduct and organizational framework of the companies toward the market and the world economic juncture. Nevertheless, researches demonstrate that a good number of enterprises of this nature fail. In this sense, this study aimed at characterizing the formation and sustentation of a strategic alliance which has already been formed for 26 years and, thus, verifying the main foundations which are responsible for the maintenance of the union health. The unity of analysis was the alliance between companies as FEMSA and CVI Indústria de Refrigerantes Ltda. Through the method of case study, using the qualitative technique with the aim of describing the case in study, four managers and one collaborator, all of them linked to the alliance, were interviewed. The research allowed establishing that the main foundations of sustaining the alliance in study are in the individual abilities of the partnerships, in the synergy among individual strategies and in the feeling of mutual confidence which exists. Moreover, it was found out that, in the moments of crisis, the major factor responsible for the maintenance of the business is the determination of the upper management on keeping a climate of enthusiasm between the participants of the strategic alliance.

  12. Animal Bone Char Solubilization with Itaconic Acid Produced by Free and Immobilized Aspergillus terreus Grown on Glycerol-Based Medium

    NARCIS (Netherlands)

    Vassilev, N.; Medina, A.; Eichler-Lobermann, B.; Flor-Peregrin, E.; Vassileva, M.

    2012-01-01

    Cells of Aspergillus terreus, free and immobilized in polyurethane foam, were employed in itaconic acid fermentation processes on glycerol-based media. The purpose was to assess their suitability for animal bone char solubilization and the development of a biotechnological alternative to P fertilize

  13. Mathematical Optimization for the Virtual Design of Process Chains with Electromagnetic Forming

    OpenAIRE

    Rozgic, M.; Stiemer, M.

    2016-01-01

    In this work, a framework for virtual process design for coupled processes including electromagnetic impulse forming is presented. Virtual process design is here understood as the computer based identification of suitable geometry and process parameters to reach a predefined forming result via physically feasible process paths. Implementation of this concept relies on three pillars: a physical process model, its implementation within a numerical simulation, and a mathematical o...

  14. Optimization of Process Parameters of Stamping Forming of the Automotive Lower Floor Board

    OpenAIRE

    Ma, Guoying; Huang, Binbing

    2014-01-01

    There are many process parameters which have great effect on the forming quality of parts during automobile panel stamping forming process. This paper took automotive lower floor board as the research object; the forming process was analyzed by finite element simulation using Dynaform. The influences of four main process parameters including BHF (blank holder force), die corner radius, friction coefficient, and die clearance on the maximum thinning rate and the maximum thickening rate were re...

  15. Process modelling and die design concepts for forming aircraft sheet parts

    Science.gov (United States)

    Hatipoğlu, H. A.; Alkaş, C. O.

    2016-08-01

    This study is about typical sheet metal forming processes applied in aerospace industry including flexform, stretch form and stretch draw. Each process is modelled by using finite element method for optimization. Tensile, bulge, forming limit and friction tests of commonly used materials are conducted for defining the hardening curves, yield loci, anisotropic constants, forming limit curves and friction coefficients between die and sheet. Process specific loadings and boundary conditions are applied to each model. The models are then validated by smartly designed experiments that characterize the related forming processes. Lastly, several examples are given in which those models are used to predict the forming defects before physical forming and necessary die design and process parameter changes are applied accordingly for successful forming operations.

  16. FE simulation and process analysis on forming of aluminum alloy multi-layer cylinder parts with flow control forming

    Institute of Scientific and Technical Information of China (English)

    WANG Xin-yun; WU You-sheng; XIA Ju-chen; HU Guo-an

    2005-01-01

    The aluminum alloy parts used in airbag of car were studied with flow control forming(FCF) method,which was a good way to low forming force and better mechanical properties. The key technology of FCF was the design of control chamber to divide metal flow. So, the design method of FCF was analyzed and two type of control chamber were put forward. According to divisional principle, calculation model of forming force and approximate formula were given. Then forming process of aluminum alloy multi-layer cylinder parts was simulated. The effect of friction factor, die radius and punch velocity on metal flow and forming force was obtained. Finally, the experiment was preformed under the direction of theory and finite element(FE) simulation results. And the qualified parts were manufactured. The simulation data and experimental results show that the forming sequence of inner wall and outer wall, and then the force step, can be controlled by adjusting the process parameters. And the FCF technology proposed has very important application value in precision forging.

  17. Fixed-bed adsorption study of methylene blue onto pyrolytic tire char

    Science.gov (United States)

    Makrigianni, Vassiliki; Giannakas, Aris; Papadaki, Maria; Albanis, Triantafyllos; Konstantinou, Ioannis

    2016-04-01

    In this work, the adsorption efficiency of acid treated pyrolytic tire char to cationic methylene blue (MB) dye adsorption from aqueous solutions was investigated by fixed-bed adsorption column experiments. The effects of the initial dye concentration (10 - 40 mg L-1) and feed flow rate (50 - 150 mL min -1) with a fixed bed height (15 cm) were studied in order to determine the breakthrough characteristics of the adsorption system. The Adams-Bohart, Yoon-Nelson and Thomas model were applied to the adsorption of MB onto char at different operational conditions to predict the breakthrough curves and to determine the characteristic parameters of the column. The results showed that the maximum adsorbed quantities decreased with increasing flow rate and increased with increasing initial MB concentration. Breakthrough time and exhaustion time increased with decreasing inlet dye concentration and flow rate. In contrast with Adams-Bohart model, Yoon-Nelson model followed by Thomas model were found more suitable to describe the fixed-bed adsorption of methylene blue by char. The correlation coefficient values R2 for both models at different operating conditions are higher than 0.9 and the low average relative error values provided very good fittings of experimental data at different operating conditions. Higher adsorption capacity of 3.85 mg g -1 was obtained at 15 cm of adsorbent bed height, flow rate of 100 mL min -1and initial MB concentration of 40 mg L-1. Although that activated carbons exhibited higher adsorption capacities in the literature, acid-treated pyrolytic tire char was found to be considerably efficient adsorbent for the removal of MB dye column taking into account the advantages of the simpler production process compared to activated carbons, as well as, the availability of waste tire feedstock and concurrent waste tire management.

  18. Bone char surface modification by nano-gold coating for elemental mercury vapor removal

    Energy Technology Data Exchange (ETDEWEB)

    Assari, Mohamad javad [Department of Environmental & Occupational Health, Faculty of Medical Sciences, Tarbiat Modares university, Tehran (Iran, Islamic Republic of); Rezaee, Abbas, E-mail: rezaee@modares.ac.ir [Department of Environmental & Occupational Health, Faculty of Medical Sciences, Tarbiat Modares university, Tehran (Iran, Islamic Republic of); Rangkooy, Hossinali [Occupational Health Department, Faculty of Health, Jondishapor Medical Sciences University, Ahvaz (Iran, Islamic Republic of)

    2015-07-01

    Highlights: • A novel nanocomposite including bone char and gold nanoparticle was developed for capture of Hg{sup 0} vapor. • EDS and XRD results confirm the presence of nano-gold on the surface of the bone char support. • The majority of the pores were found to be in the mesoporous range. • The dynamic capacity of 586 μg/g was obtained for Hg{sup 0} vapor. - Abstract: The present work was done to develop a novel nanocomposite using bone char coated with nano-gold for capture of elemental mercury (Hg{sup 0}) from air. The morphologies, structures, and chemical constitute of the prepared nanocomposite were evaluated by UV–VIS–NIR, dynamic light-scattering (DLS), X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infra-red (FTIR) spectroscopy, and energy dispersive X-ray spectroscopy (EDS). The capture performance of nanocomposite was evaluated in a needle trap for mercury vapor. An on-line setup based on cold vapor atomic absorption spectrometry (CVAAS) was designed for Hg{sup 0} determination. Dynamic capacity of nanocomposite for Hg{sup 0} was shown high efficient operating capacity of 586.7 μg/g. As temperature increases, the dynamic adsorption capacity of the nanocomposite was decreased, which are characteristics of physicosorption processes. It was found that the surface modification of bone char with nano-gold has various advantages such as high operating dynamic adsorption capacity and low cost preparation. It was also demonstrated that the developed nanocomposite is suitable for on-line monitoring of Hg{sup 0}. It could be applied for the laboratory and field studies.

  19. Bone char surface modification by nano-gold coating for elemental mercury vapor removal

    International Nuclear Information System (INIS)

    Highlights: • A novel nanocomposite including bone char and gold nanoparticle was developed for capture of Hg0 vapor. • EDS and XRD results confirm the presence of nano-gold on the surface of the bone char support. • The majority of the pores were found to be in the mesoporous range. • The dynamic capacity of 586 μg/g was obtained for Hg0 vapor. - Abstract: The present work was done to develop a novel nanocomposite using bone char coated with nano-gold for capture of elemental mercury (Hg0) from air. The morphologies, structures, and chemical constitute of the prepared nanocomposite were evaluated by UV–VIS–NIR, dynamic light-scattering (DLS), X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infra-red (FTIR) spectroscopy, and energy dispersive X-ray spectroscopy (EDS). The capture performance of nanocomposite was evaluated in a needle trap for mercury vapor. An on-line setup based on cold vapor atomic absorption spectrometry (CVAAS) was designed for Hg0 determination. Dynamic capacity of nanocomposite for Hg0 was shown high efficient operating capacity of 586.7 μg/g. As temperature increases, the dynamic adsorption capacity of the nanocomposite was decreased, which are characteristics of physicosorption processes. It was found that the surface modification of bone char with nano-gold has various advantages such as high operating dynamic adsorption capacity and low cost preparation. It was also demonstrated that the developed nanocomposite is suitable for on-line monitoring of Hg0. It could be applied for the laboratory and field studies

  20. Bio-char from treated and untreated oil palm fronds

    Science.gov (United States)

    Sulaiman, Fauziah; Abdullah, Nurhayati; Rahman, Aizuddin Abdul

    2013-05-01

    The palm oil industry generates almost 94% of biomass in Malaysia, while other agricultural and forestry by-products contribute the remaining of 6%. Oil palm fronds (OPF) are estimated to be the highest available biomass amounting to 44.84 million tonnes in Malaysia. However, studies on OPF for thermochemical conversion technology which has good potential for energy conversion are still lacking. In this work, pyrolysis of OPF is conducted by using a fixed bed reactor. Samples were carbonized at slow pyrolysis temperature of around 300 to 500°C with heating rate of 10°C min-1. In addition, samples were treated for 20 min with distilled water at ambient temperature to reduce the ash content. Effectiveness of pre-treatment can be determined by observing the percentage of ash content reduction of each sample after undergoing washing pre-treatment. At 300°C, the char yields of the untreated OPF were slightly higher at 50.95% compared to the treated sample at 49.77%. Approximately all bio-char from the treated samples have better high heating value (HHV) of around 18-20 MJ kg-1 compared to the untreated samples. Besides that, all treated OPF char is more carbon rich and considered to be environmental friendly due to its low nitrogen content compared to the untreated OPF char. In this work, microscopic analysis of OPF bio-char were also studied by observing and evaluating their structure surface and morphology.

  1. Gasification reactivity of biomass chars with CO{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Dong Kyun; Lee, Sun Ki; Kang, Min Woong; Hwang, Jungho [Department of Mechanical Engineering, Yonsei University, 134 Sinchon-dong, Seodaemun-gu, Seoul (Korea, Republic of); Yu, Tae-U. [High Temperature Processing R and D Department of Korea Institute of Industrial Technology, 35-3, Hongchon-Ri, Ipchang-Myun, Seobuk-Gu, Chonan-Si (Korea, Republic of)

    2010-12-15

    In this study, carbon conversion was calculated from the data obtained with a real-time gas analyzer. In a lab-scale furnace, each biomass sample was pyrolyzed in a nitrogen environment and became biomass char. For preparation of the char, the furnace was electrically heated over 40 min up to the wall temperature of 850 C, and maintained at the same temperature over 17 min. The furnace was again heated over 3 min to a temperature higher than 850 C and then CO{sub 2} was injected. The biomass char was then gasified with CO{sub 2} under isothermal conditions. The reactivity of biomass char was investigated at various temperatures and CO{sub 2} concentrations. The VRM (volume reaction model), SCM (shrinking core model), and RPM (random pore model) were used to interpret the experimental data. For each model, the activation energy (E) and pre-exponential factor (A) of the biomass char-CO{sub 2} reaction were determined from gas-analysis data by using the Arrhenius equation. For the RPM, the apparent reaction order was determined. According to this study, it was found that the experimental data agreed better with the RPM than with the other two models. Through BET analyses, it was found that the structural parameter ({psi}) of the surface area for the RPM was obtained as 4.22. (author)

  2. Differences in morphological properties between the olivine group minerals formed in natural and industrial processes

    OpenAIRE

    Dević S.; Marčeta L.

    2007-01-01

    Olivines are a large isomorphic series of minerals, belonging to silicates group. Regardless of their chemical composition, any of these minerals can be formed both in natural and industrial processes. The aim of this work is to describe these minerals and differences of morphological properties between the olivines formed in nature, and those formed as byproducts of some industrial processes , as Process Metalurgy-Ironmaking. The olivines whose formation is tied to rock masses (natural proce...

  3. Suprasubduction volcanic rocks of the Char ophiolite belt, East Kazakhstan: new geochemical and first geochronological data

    Science.gov (United States)

    Safonova, Inna; Simonov, Vladimir; Seltmann, Reimar; Yamamoto, Shinji; Xiao, Wenjiao

    2016-04-01

    The Char ophiolite belt is located in the western Central Asian Orogenic Belt, a world largest accretionary orogen, which has evolved during more than 800 Ma. The Char belt formed during Kazakhstan - Siberia collision. It has been known for hosting fragments of Late Devonian-Early Carboniferous oceanic crust, MORB, OPB and OIB, of the Paleo-Asian Ocean (Safonova et al., 2012). The Char is surrounded by two Paleozoic island-arc terranes: Zharma-Saur in the west and Rudny Altai in the east, however, until recent times, no island-arc units have been found within it. We were the first to find island-arc units as tectonic sheets occurring adjacent to those consisting of oceanic rocks. In places, island-arc andesites cut oceanic basalts. The Char volcanic and subvolcanic rocks of a probable suprasubduction origin are basalt, microgabbro, dolerite, andesite, tonalite and dacite. The mafic to andesitic volcanics possessing low TiO2 (0.85 wt.%av.) and show MgO vs. major elements crystallization trends suggesting two magma series: tholeiitic and calc-alkaline. The tholeiitic varieties are less enriched in incompatible elements then the calc-alkaline ones. Two samples are high-Mg and low-Ti andesibasalts similar to boninites. The rocks possess moderately LREE enriched rare-earth element patterns and are characterized by negative Nb anomalies present on the multi-element spectra (Nb/Lapm = 0.14-0.47; Nb/Thpm = 0.7-1.6).The distribution of rare-earth elements (La/Smn = 0.8-2.3, Gd/Ybn = 0.7-1.9) and the results of geochemical modeling in the Nb-Yb system suggest high degrees of melting of a depleted harzburgite-bearing mantle source at spinel facies depths. Fractional crystallization of clinopyroxene, plagioclase and opaque minerals also affected the final composition of the volcanic rocks. Clinopyroxene monomineral thermometry indicates crystallization of melts at 1020-1180°C. Melt inclusion composition based numerical calculations show that primary melts were derived at 1350

  4. Mechanical Characterization of Bio-Char Made Hybrid Composite

    Directory of Open Access Journals (Sweden)

    Amit pandey

    2016-08-01

    Full Text Available Material discoveries and development have always been the cause of the growth and development of a nation and the need of naturally made materials is the need of hours. Thus this paper takes you to the development of a hybrid composite made of sisal fiber with epoxy as the matrix intertwined with softwood bio-char. Softwood chip bio-char, produced by slow pyrolysis, has a porous structure improving its nutrient absorbing capacity, surface area and thus a potential substituent. Bio-char has an appreciable carbon sequestration value i.e. a carbon absorbing product. The orientation of sisal fiber are changed and studied in longitudinal and orthogonal direction indicating superiority of longitudinal fiber orientation .It also addresses the variation in mechanical characteristic (tensile flexural and impact with different constituent of the new composite and its position in material selection charts with a direction for further work.

  5. Heat Transfer in a Fixed Bed of Straw Char

    DEFF Research Database (Denmark)

    Fjellerup, Jan Søren; Henriksen, Ulrik Birk; Jensen, Anker;

    2003-01-01

    A model for the thermal conductivity of a straw char bed has been developed. The model extends the work of Yagi and Kunii to describe heat transfer in a bed of cylinders, using a relationship between the interparticle distance and the external porosity. To verify the model, thermal conductivity...... experiments were performed on shredded and un-shredded straw char samples, varying particle size, bed packing (loose or dense), and temperature. Predictions with the model, using the measured external porosity and particle diameter as input parameters, are in agreement with measurements within...... the experimental uncertainty over the range of conditions investigated. The heat transfer model was used in a parametric study to evaluate the effect of gas flow rate, particle diameter, porosity, and temperature on the thermal conductivity in a straw char bed....

  6. Caracterização dos produtos líquidos e do carvão da pirólise de serragem de eucalipto Characterization of liquid products and char from the pyrolysis of eucalyptus sawdust

    Directory of Open Access Journals (Sweden)

    Ayrton F. Martins

    2007-08-01

    Full Text Available This study proposes the low temperature pyrolysis as an alternative conversion process for residual biomass and for obtaining gaseous, liquid and solid chemical feedstocks. Using a bench electrical pyrolysis oven, four product fractions from eucalyptus sawdust were obtained: a gaseous one, two liquid (aqueous and oily, and a solid residue (char. These products were characterized by different analytical methods. The liquid fractions showed themselves as potential sources for input chemicals. The residual char revealed appreciable adsorption capability. The process demonstrated good efficiency, generating at least two fractions of great industrial interest: bio oil and char.

  7. Development of Replacements for Phoscoating Used in Forging, Extrusion and Metal Forming Processes

    Energy Technology Data Exchange (ETDEWEB)

    Kerry Barnett

    2003-03-01

    Many forging, extrusion, heading and other metal forming processes use graphite-based lubricants, phosphate coatings, and other potentially hazardous or harmful substances to improve the tribology of the metal forming process. The application of phosphate-based coatings has long been studied to determine if other synthetic ''clean'' lubricants could provide the same degree of protection afforded by phoscoatings and its formulations. So far, none meets the cost and performance objectives provided by phoscoatings as a general aid to the metal forming industry. In as much as phoscoatings and graphite have replaced lead-based lubricants, the metal forming industry has had previous experience with a legislated requirement to change processes. However, without a proactive approach to phoscoating replacement, many metal forming processes could find themselves without a cost effective tribology material necessary for the metal forming process

  8. Influence of Process Parameters on Forming of Arched Aircraft Skin with Aluminum Alloy 2024

    Science.gov (United States)

    Yan, Huajun; Zhang, Shuangjie; Gao, Ying

    To solve these problems such as easily springback and hardly controlling the loading direction when arched aircraft skin is formed, stretch forming of steel plate with aluminium alloy 2024 was simulated by the finite element software Abaqus, and the shape of the stretch forming die was the arc with radius 350mm. The influence of process parameters, such as stretch forming track and dangling length on forming of arched aircraft skin was researched, and the reasonable range of stretch forming length track and dangling length was given. The results have significance for research the forming law of arched aircraft skin.

  9. A Risk-Based Strategy for Evaluating Mitigation Options for Process-Formed Compounds in Food

    OpenAIRE

    Hanlon, Paul; Brorby, Gregory P.; Krishan, Mansi

    2016-01-01

    Processing (eg, cooking, grinding, drying) has changed the composition of food throughout the course of human history; however, awareness of process-formed compounds, and the potential need to mitigate exposure to those compounds, is a relatively recent phenomenon. In May 2015, the North American Branch of the International Life Sciences Institute (ILSI North America) Technical Committee on Food and Chemical Safety held a workshop on the risk-based process for mitigation of process-formed com...

  10. Effects of rice husks and their chars from hydrothermal carbonization on the germination rate and root length of Lepidium sativum

    Science.gov (United States)

    Kern, Jürgen; Mukhina, Irina; Dicke, Christiane; Lanza, Giacomo; Kalderis, Dimitrios

    2015-04-01

    Currently, char substrates gain a lot of interest, since they are being discussed as a component in growing media, which may become one option for the replacement of peat. Among different thermal conversion processes of biomass hydrothermal carbonization (HTC) has been found to produce chars with similar acidic pH values like peat. The question however is, if these hydrochars, which may contain toxic phenolic compounds are suitable to be introduced as a new substitute for peat in horticulture. In this study rice husk were hydrothermally carbonized at 200° C for 6 hours, yielding in hydrochars containing organic contaminants such as phenols and furfurals, which may affect plants and soil organisms. We investigated potential toxic effects on the germination rate and the root length of cress salad (Lepidium sativum) in four fractions: i) soil control, ii) raw rice husk + soil, iii) unwashed rice char + soil and iv) acetone/water washed rice char + soil. It could be shown that phenols and furfurals, which were removed from the hydrochar after washing by 80 to 96% did not affect the germination rate and the root length of the cress plants. The lowest germination rate and root length were found in the soil control, the highest in the non-washed hydrochar treatment, indicating a fertilization effect and growth stimulation of cress salad by hydrochar. If this result can be confirmed for other target and non-target organisms in future studies, a new strategy for the production of growing media may be developed.

  11. OPTIMIZATION OF CHAR FOR NOx REMOVAL; FINAL

    International Nuclear Information System (INIS)

    Work performed for this study demonstrates that the temperature of treatment and the identity of the treatment gas both strongly impact the surface chemistry of activated carbon. Two commercial activated carbons were treated in either N(sub 2) or H(sub 2) at different temperatures up to 2600 C. Several techniques-including microcalorimetry, point of zero charge measurements, thermal desorption-were used to provide insight into important aspects of the chemical surface properties. The results show that activated carbons treated at high temperatures (ca. 950 C) in hydrogen will not react with oxygen and water at ambient temperatures; moreover, surfaces created in this fashion have stable properties in ambient conditions for many months. In contrast, the same carbons treated in an inert gas (e.g., N(sub 2)) will react strongly with oxygen and water at ambient temperatures. In the presence of platinum (or any other noble metal), stable basic carbons, which will not adsorb oxygen in ambient laboratory conditions, can be created via a relatively low-temperature process. Treatment at higher temperatures ( and gt;1500 C) produced increasingly stable surfaces in either N(sub 2) or H(sub 2). A structural model is proposed. To wit: Treatment at high temperatures in any gas will lead to the desorption of oxygen surface functionalities in the form of CO and/or CO(sub 2). Absent any atom rearrangement, the desorption of these species will leave highly unsaturated carbon atoms (''dangling carbons'') on the surface, which can easily adsorb O(sub 2) and H(sub 2)O. In an inert gas these ''dangling carbons'' will remain, but hydrogen treatments will remove these species and leave the surface with less energetic sites, which can only adsorb O(sub 2) at elevated temperatures. Specifically, hydrogen reacts with any highly unsaturated carbons in the surface to form methane. At temperatures greater than 1500 C (e.g., 1800 C, 2600 C), structural annealing takes place and the consequent

  12. Formation of structure, phase composition and properties of electro explosion resistant coatings using electron-beam processing

    Energy Technology Data Exchange (ETDEWEB)

    Romanov, Denis A., E-mail: romanov-da@physics.sibsiu.ru, E-mail: kos2906@mail.ru, E-mail: budovskih-ea@physics.sibsiu.ru, E-mail: gromov@physics.sibsiu.ru, E-mail: da-rom@live.ru; Sosnin, Kirill V., E-mail: romanov-da@physics.sibsiu.ru, E-mail: kos2906@mail.ru, E-mail: budovskih-ea@physics.sibsiu.ru, E-mail: gromov@physics.sibsiu.ru, E-mail: da-rom@live.ru; Budovskikh, Evgenij A., E-mail: romanov-da@physics.sibsiu.ru, E-mail: kos2906@mail.ru, E-mail: budovskih-ea@physics.sibsiu.ru, E-mail: gromov@physics.sibsiu.ru, E-mail: da-rom@live.ru; Gromov, Viktor E., E-mail: romanov-da@physics.sibsiu.ru, E-mail: kos2906@mail.ru, E-mail: budovskih-ea@physics.sibsiu.ru, E-mail: gromov@physics.sibsiu.ru, E-mail: da-rom@live.ru; Semin, Alexander P., E-mail: romanov-da@physics.sibsiu.ru, E-mail: kos2906@mail.ru, E-mail: budovskih-ea@physics.sibsiu.ru, E-mail: gromov@physics.sibsiu.ru, E-mail: da-rom@live.ru [Siberian State Industrial University, Novokuznetsk, 654007 (Russian Federation)

    2014-11-14

    For the first time, the high intensity electron beam modification of electroexplosion composite coatings of Mochar description='Single-Bond' name='Single-Bond' value='Single-Bond'/>Cu, Mochar description='Single-Bond' name='Single-Bond' value='Single-Bond'/>Cchar description='Single-Bond' name='Single-Bond' value='Single-Bond'/>Cu, Wchar description='Single-Bond' name='Single-Bond' value='Single-Bond'/>Cu, Wchar description='Single-Bond' name='Single-Bond' value='Single-Bond'/>Cchar description='Single-Bond' name='Single-Bond' value='Single-Bond'/>Cu and TiB{sub 2}char description='Single-Bond' name='Single-Bond' value='Single-Bond'/>Cu systems was done. The studies of phase and elemental composition, defective structure conditions of these coatings were carried out. The regimes of electron-beam processing making possible to form the dense, specular luster surface layers having a submicrocrystalline structure were revealed. It was established that electron-beam processing of elecroexplosion spraying of layer of elecroexplosion spraying carried out in the regime of melting results in the formation of structurally and contrationally homogeneous surface layer. Investigation of the effect of electron-beam processing of electroexplosion electroerosion resistant coatings on their tribological properties (wear resistanse and coefficient of friction) and electroerosion resistance was done. It was shown that all the examined costings demonstrate the increase of electroerosion resistance in spark erosion up to 10 times.

  13. Utilization of oil palm tree residues to produce bio-oil and bio-char via pyrolysis

    International Nuclear Information System (INIS)

    Highlights: • About 14.72% of the total landmass in Malaysia was used for oil palm plantations. • Oil palm tree residues were pyrolyzed to produce bio-oil and bio-char. • The process was performed at a temperature of 500 °C and reaction time of 60 min. • Characterization of the products was performed. - Abstract: Oil palm tree residues are a rich biomass resource in Malaysia, and it is therefore very important that they be utilized for more beneficial purposes, particularly in the context of the development of biofuels. This paper described the possibility of utilizing oil palm tree residues as biofuels by producing bio-oil and bio-char via pyrolysis. The process was performed in a fixed-bed reactor at a temperature of 500 °C, a nitrogen flow rate of 2 L/min and a reaction time of 60 min. The physical and chemical properties of the products, which are important for biofuel testing, were then characterized. The results showed that the yields of the bio-oil and bio-char obtained from different residues varied within the ranges of 16.58–43.50 wt% and 28.63–36.75 wt%, respectively. The variations in the yields resulted from differences in the relative amounts of cellulose, hemicellulose, lignin, volatiles, fixed carbon, and ash in the samples. The energy density of the bio-char was found to be higher than that of the bio-oil. The highest energy density of the bio-char was obtained from a palm leaf sample (23.32 MJ/kg), while that of the bio-oil was obtained from a frond sample (15.41 MJ/kg)

  14. Simulation of Forming Process as an Educational Tool Using Physical Modeling

    Science.gov (United States)

    Abdullah, A. B.; Muda, M. R.; Samad, Z.

    2008-01-01

    Metal forming process simulation requires a very high cost including the cost for dies, machine and material and tight process control since the process involve very huge pressure. A physical modeling technique is developed and initiates a new era of educational tool of simulating the process effectively. Several publications and findings have…

  15. Diversity of optical signal processing led by optical signal form conversion

    Energy Technology Data Exchange (ETDEWEB)

    Konishi, Tsuyoshi, E-mail: konishi@mls.eng.osaka-u.ac.j [Osaka University, 2-1 Yamadaoka, Suita Osaka 565-0871 (Japan)

    2010-02-01

    This paper reviews opportunities of optical signal form conversion as typified by time-space conversion in optical signal processing. Several examples of typical ultra-fast optical signal processing using optical signal form conversion are described and their applications are introduced in respect to photonic networks, ultra-fast measurement, and so on.

  16. A Comparison of Diary Method Variations for Enlightening Form Generation in the Design Process

    Science.gov (United States)

    Babapour, Maral; Rehammar, Bjorn; Rahe, Ulrike

    2012-01-01

    This paper presents two studies in which an empirical approach was taken to understand and explain form generation and decisions taken in the design process. In particular, the activities addressing aesthetic aspects when exteriorising form ideas in the design process have been the focus of the present study. Diary methods were the starting point…

  17. Keep your eyes on development - The behavioural and neurophysiological development of visual mechanisms underlying form processing

    Directory of Open Access Journals (Sweden)

    Carlijn eVan Den Boomen

    2012-03-01

    Full Text Available Visual form perception is essential for correct interpretation of, and interaction with, our environment. Form perception depends on visual acuity and processing of specific form characteristics, such as luminance contrast, spatial frequency, colour, orientation, depth and even motion information. As other cognitive processes, form perception matures with age. This paper aims at providing a concise overview of our current understanding of the typical development, from birth to adulthood, of form-characteristic processing, as measured both behaviourally and neurophysiologically. Two main conclusions can be drawn. First, the current literature conveys that for most reviewed characteristics a developmental pattern is apparent. These trajectories are discussed in relation to the organisation of the visual system. The second conclusion is that significant gaps in the literature exist for several age-ranges. To complete our understanding of the typical and, by consequence, atypical development of visual mechanisms underlying form processing, future research should uncover these missing segments.

  18. PROCESS VALIDATION OF SOLID ORAL DOSAGE FORM AND PROCESS VALIDATION GUIDANCE FOR INDUSTRY

    OpenAIRE

    Chakarvarty Gourish; Seth Nimrata; Sharma Vishal

    2013-01-01

    Validation is one of the important steps in achieving and maintaining the quality of the final product. Validation of the individual steps of the processes is called the process validation. Process validation's main objective continues to be the generation of a process which yields a product which meets pre-determined quality criteria. It is an important component in the design, prototyping and manufacturing process and one, if done correctly, that can save a considerable amount of time, mon...

  19. Experimental comparison of biomass chars with other catalysts for tar reduction

    NARCIS (Netherlands)

    Abu El-Rub, Z.; Bramer, E.A.; Brem, G.

    2008-01-01

    In this paper the potential of using biomass char as a catalyst for tar reduction is discussed. Biomass char is compared with other known catalysts used for tar conversion. Model tar compounds, phenol and naphthalene, were used to test char and other catalysts. Tests were carried out in a fixed bed

  20. Single point incremental sheet forming investigated by in-process 3D digital image correlation

    Directory of Open Access Journals (Sweden)

    Bernhart G.

    2010-06-01

    Full Text Available Single Point Incremental Forming (SPIF is a promising sheet metal forming process for prototyping and small batches, in which the blank is formed in a stepwise fashion by a displacement-controlled small-sized tool. Due to specific strain paths induced by the process and limited plastic zones in the contact region between the tool and the workpiece, forming diagrams and forming strategies are different from the classical stamping processes. One major limitation of SPIF is the lack of accuracy of the obtained final parts because of the poor knowledge of the state of stress during the process that requires a good description of the material models and a right choice of the process parameters. In this paper, the SPIF process is experimentally investigated by the mean of surface 3D digital image correlation during the forming of a AW-5086-H111 grade aluminium alloy. Development of strain fields encountered in incremental forming is reported and material formability is evaluated on several formed shapes, taking into account a wide range of straining conditions of this process.

  1. Heat Transfer in a Fixed Biomass Char Bed

    DEFF Research Database (Denmark)

    Fjellerup, Jan Søren; Henriksen, Ulrik Birk; Glarborg, P.;

    2002-01-01

    A thermal conductivity model based on the Yagi and Kunii model together with a bed model was developed to describe the thermal conductivity of a straw char bed. The bed model describes the relationship between the distance between particles and the external porosity. To verify the model, thermal...

  2. Bone char quality and defluoridation capacity in contact precipitation

    DEFF Research Database (Denmark)

    Albertus, J.; Bregnhøj, Henrik; Kongpun, M.

    2002-01-01

    Samples from six different brands of bone char are tested for their capacity to remove fluoride from water in batch. Initial concentrations of 10 mg/L and contact times of 6 hours are used. The removal capacities observed are 0.6-1.1 mg/g on an average, s.d. being 0.16. Addition of calcium and ph...

  3. Sensitivity analysis of roll load, torque and material properties in the roll forming process

    Science.gov (United States)

    Abeyrathna, Buddhika; Rolfe, Bernard; Hodgson, Peter; Weiss, Matthias

    2013-12-01

    Advanced High Strength Steel (AHSS) and Ultra High Strength Steel (UHSS) are increasingly used in the current automotive industry because of their high strength and weight saving potential. As a sheet forming process, roll forming is capable of forming such materials with precise dimensions, however a small change in processing may results in significant change in the material properties such as yield strength and hardening exponent from coil to coil or within the same coil. This paper presents the effect of yield strength and the hardening exponent on roll load, torque of the roll forming process and the longitudinal bow. The roll forming process is numerically simulated, and then the regression analysis and Analysis of Variance (ANOVA) techniques are employed to establish the relationships among the aforementioned parameters and to determine the percentage influence of material properties on longitudinal bow, roll load and torque.

  4. Char-recirculation biomass gasification system--a site-specific feasibility study

    International Nuclear Information System (INIS)

    A site-specific feasibility study was conducted for a char-recirculation biomass gasification plant which would dispose of the chippable solid residues of the area sawmills. The plant would receive green hardwood chips and convert them into active charcoal while producing process steam and electrical power. An economic analysis was performed on the basis of not-for-profit operation, marketing crushed active charcoal to a broker at a discounted price, and displacing purchased electric power. Given a market for the active charcoal, the plant was judged to be economically viable

  5. Importance of fragmentation on the steady state combustion of wood char in a bubbling fluidized bed

    Energy Technology Data Exchange (ETDEWEB)

    Pinho, Carlos [Universidade do Porto (CEFT/FEUP), Porto (Portugal). Faculdade de Engenharia. Centro de Estudos de Fenomenos de Transporte], E-mail: ctp@fe.up.pt

    2010-07-01

    A simple mathematical model for the analysis of the steady state behavior of a bubbling fluidized bed burner is presented, with the main intention of evaluating the importance of the primary fragmentation of fuel particles on the performance of this type of burners. This model has pedagogical advantages because of its simplicity and easiness of application to the analysis of realistic situations. The model is based upon the classical models used for the study of batch combustion processes in fluidized bed reactors. Experimental data from studies of fluidized bed combustion of portuguese vegetable chars are used to support the analysis of the performance of a 1 m diameter fluidized bed combustor. (author)

  6. Type of litter determines the formation and properties of charred material during wildfires

    Science.gov (United States)

    Chavez, Bruno; Fonturbel, M. Teresa; Salgado, Josefa; García-Oliva, Felipe; Vega, Jose A.; Merino, Agustin

    2014-05-01

    Wildfire is one of the most important disturbances all over the World, affecting both the amount and composition of forest floor and mineral soils. In comparison with unburnt areas, wildfire-affected forest floor usually shows lower contents of labile C compounds and higher concentrations of recalcitrant aromatic forms. These changes in composition can have important impact on biogeochemical cycles and therefore ecosystem functions. Although burning of different types of litter can lead to different amount and types of pyrogenic compounds, this aspect has not been evaluated yet. The effect of wildfire on SOM composition and stability were evaluated in five major types of non-wood litter in Mediterranean ecosystems: Pinus nigra, E. arborea, P. pinaster, U. europaeus and Eucalyptus globulus. In each of these ecosystems, forest floor samples from different soil burn severities were sampled. Soil burnt severities were based on visual signs of changes in forest floor and deposition of ash. Pyrogenic carbon quality were analysed using elementary analysis, solid-state 13 C nuclear magnetic resonance spectroscopy, Reflectance Infrared Fourier Transform (FTIR) and thermal analysis (simultaneous DSC-TG). The study showed that the different types of litter influenced the formation and characteristics of charred material. They differed in the temperature at which they start to be formed, the amounts of charred compounds and in their chemical composition. The resulting charred materials from the different litter, showed an important variability in the degree of carbonitation/aromatization. Unlike the biochar obtained through pyrolysis of woody sources, which contains exclusively aromatic structures, in the charred material produced in some litter, lignin, cellulose and even cellulose persist even in the high soil burnt severity. Coinciding with increases in aromatic contents, important decreases in atomic H/C and O/C ratios were recorded. However, the values found in some

  7. Interactions between motion and form processing in the human visual system

    Directory of Open Access Journals (Sweden)

    George eMather

    2013-05-01

    Full Text Available The predominant view of motion and form processing in the human visual system assumes that these two attributes are handled by separate and independent modules. Motion processing involves filtering by direction-selective sensors, followed by integration to solve the aperture problem. Form processing involves filtering by orientation-selective and size-selective receptive fields, followed by integration to encode object shape. It has long been known that motion signals can influence form processing in the well-known Gestalt principle of common fate; texture elements which share a common motion property are grouped into a single contour or texture region. However recent research in psychophysics and neuroscience indicates that the influence of form signals on motion processing is more extensive than previously thought. First, the salience and apparent direction of moving lines depends on how the local orientation and direction of motion combine to match the receptive field properties of motion-selective neurons. Second, orientation signals generated by ‘motion-streaks’ influence motion processing; motion sensitivity, apparent direction and adaptation are affected by simultaneously present orientation signals. Third, form signals generated by human body shape influence biological motion processing, as revealed by studies using point-light motion stimuli. Thus form-motion integration seems to occur at several different levels of cortical processing, from V1 to STS.

  8. [Morphology of soil iron oxides and its correlation with soil-forming process and forming conditions in a karst mountain].

    Science.gov (United States)

    Zhang, Zhi-Wei; Zhu, Zhang-Xiong; Fu, Wa-Li; Wen, Zhi-Lin

    2012-06-01

    The quantity and morphology of iron oxides are indicators of soil forming-process and forming conditions. In order to analyze the connection between soil iron oxides and soil forming conditions and degenerative process of karst ecosystem, we have chosen 14 soil profiles on the top and middle section of Jinfo Mountain, a typical karst slope in Chongqing, China. Morphology and contents of soil iron oxides were studied by using chemical selective extraction techniques. We draw conclusions: 1) total iron (Fe(t)) is mainly controlled by parent material and lithology. Significant difference of Fe(t) content exists between soils in Top Mountain (51.49 g x kg(-1), mean value from 5 profiles) and soils at the middle sector of North Slope (86.29 g x kg(-1), mean value of 9 profiles); 2) the results show low concentration of F(d) (29.16 g x kg(-1)) and low ratio of Fe(d) to Fe(t)(35.40%) in soil clay under conditions of high elevation and low temperature on Top Mountain. In contrast, the results indicate advanced weathering and soil-forming process at middle slope sites due to high temperature; this is supported by high mean values of Fe(d) (43.92 g x kg(-1)) and ratio of Fe(d)/Fe(t) in clay (60.41%); 3) long humid climatic setting and large numbers of soil organic matter on top of the mountain result in high activation degrees (F(o)/Fe(d)) and high complexation degrees (Fe(p)/Fe(d)); mean values of them are 73.51%, 17.21% respectively, which are higher than that of soils at middle slope sites (13.06%, 0.41%); 4) after degradation or deforestation of secondary forestland (pines massoniana among bushes) at middle section of the hillslope, soil free iron oxides (Fe(d)) and total iron oxides (Fe(t)) decrease as well as soil organic carbon and clay, because of progressively increasing of soil erosion. Average contents of Fe(t) and Fe(d) in clay from 2 shrub profiles are 98.25 g x kg(-1), 50.81 g x kg(-1) respectively. However, the four tillage soils we have studied reveal lower

  9. Numerical Methodology for Metal Forming Processes Using Elastoplastic Model with Damage Occurrence

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Ductile damage often occurs during metal forming processes due to the large thermo-elasto (visco) plastic flow Iocalisation. This paper presents a numerical methodology, which aims to virtually improve any metal forming processes. The methodology is based on elastoplastic constitutive equations accounting for nonlinear mixed isotropic and kinematic hardening strongly coupled with isotropic ductile damage. An adaptive remeshing scheme based on geometrical and physical error estimates including a kill element procedure is used. Some numerical results are presented to show the capability of the model to predict the damage initiation and growth during the metal forming processes.

  10. Combustion Characteristics of Lignite Char in a Laboratory-scale Pressurized Fluidized Bed Combustor

    Science.gov (United States)

    Murakami, Takahiro; Suzuki, Yoshizo

    In a dual fluidized bed gasifier, the residual char after steam gasification is burnt in riser. The objectives of this work are to clarify the effect of parameters (temperature, pressure, and particle size of lignite char) of char combustion using a laboratory-scale pressurized fluidized bed combustor (PFBC). As a result, the burnout time of lignite char can be improved with increasing operating pressure, and temperature. In addition, the decrease in the particle size of char enhanced the effect on burnout time. The initial combustion rate of the char can be increased with increasing operating pressure. The effect was decreased with increasing operating temperature. However, the effect of operating pressure was slightly changed in small particle size, such as 0.5-1.0 mm. It takes about 20 sec to burn 50% of char in the operating pressure of 0.5 MPa and the particle size of 0.5-1.0 mm.

  11. A study on the char burnout characteristics of coal and biomass blends

    Energy Technology Data Exchange (ETDEWEB)

    Behdad Moghtaderi [University of Newcastle, Callaghan, NSW (Australia). Discipline of Chemical Engineering, School of Engineering, Faculty of Engineering and Built Environment

    2007-10-15

    The char burnout characteristics of coal/biomass blends under conditions pertinent to pulverised fuel combustors were investigated by a combined modelling and experimental approach. Results indicate that blending of coal with biomass increases the likelihood of char extinction (i.e. extinction potential of the char particle in the blend), in turn, decreasing the char burnout level. Our modelling results attribute this to a reduction in the char particle size to levels below a critical dimension which appears to be a strong function of the fuel blending ratio (the weight percentage of biomass in the blend), fuel reactivity, char cloud shape and particle density number. It is demonstrated here that the drop in the char burnout level during co-firing can be effectively resolved when a more reactive secondary coal is added to the blend to minimise its extinction potential. 22 refs., 8 figs., 2 tabs.

  12. Combustion and gasification characteristics of chars from raw and torrefied biomass.

    Science.gov (United States)

    Fisher, E M; Dupont, C; Darvell, L I; Commandré, J-M; Saddawi, A; Jones, J M; Grateau, M; Nocquet, T; Salvador, S

    2012-09-01

    Torrefaction is a mild thermal pretreatment (Ttorrefaction on the gasification and oxidation reactivity of chars from torrefied and raw biomass was investigated. Thermogravimetric analysis was used to study the differences in O(2) and steam reactivity, between chars prepared from torrefied and raw willow, under both high- and low-heating-rate conditions. High-heating-rate chars were prepared at 900°C with a residence time of 2s. Low-heating-rate chars were prepared with a heating rate of 33°C/min, a maximum temperature of 850 or 1000°C, and a residence time of 30 min or 1h, respectively, at the maximum temperature. Pretreatment by torrefaction consistently reduced char reactivity. Torrefaction's impact was greatest for high-heating-rate chars, reducing reactivity by a factor of two to three. The effect of torrefaction on a residence time requirements for char burnout and gasification was estimated.

  13. Hot Granules Medium Pressure Forming Process of AA7075 Conical Parts

    Institute of Scientific and Technical Information of China (English)

    DONG Guojiang; ZHAO Changcai; PENG Yaxin; LI Ying

    2015-01-01

    High strength aluminum alloy plate has a low elongation at room temperature, which leads to the forming of its components need a high temperature. Liquid or gas is used as the pressure-transfer medium in the existing flexible mould forming process, the heat resistance of the medium and pressurizing device makes the application of aluminum alloy plate thermoforming restricted. To solve this problem, the existing medium is replaced by the heat-resisting solid granules and the general pressure equipments are applied. Based on the pressure-transfer performance test of the solid granules medium, the feasibility that the assumption of the extended Drucker-Prager linear model can be used in the finite element analysis is proved. The constitutive equation, the yield function and the theoretical forming limit diagram(FLD) of AA7075 sheet are established. Through the finite element numerical simulation of hot granules medium pressure forming(HGMF) process, not only the influence laws of the process parameters, such as forming temperature, the blank-holder gap and the diameter of the slab, on sheet metal forming performance are discussed, but also the broken area of the forming process is analyzed and predicted, which are coincided with the technological test. The conical part whose half cone angle is 15° and relative height H/d0 is 0.57, is formed in one process at 250℃. The HGMF process solves the problems of loading and seal in the existing flexible mould forming process and provides a novel technology for thermoforming of light alloy plate, such as magnesium alloy, aluminium alloy and titanium alloy.

  14. When semantics aids phonology: a processing advantage for iconic word forms in aphasia

    OpenAIRE

    Meteyard, Lotte; Stoppard, Emily; Snudden, Dee; Cappa, Stefano F.; Vigliocco, Gabriella

    2015-01-01

    Iconicity is the non-arbitrary relation between properties of a phonological form and semantic content (e.g. “moo”, “splash”). It is a common feature of both spoken and signed languages, and recent evidence shows that iconic forms confer an advantage during word learning. We explored whether iconic forms conferred a processing advantage for 13 individuals with aphasia following left-hemisphere stroke. Iconic and control words were compared in four different tasks: repetition, reading aloud, a...

  15. SIMULATION OF THE PROCESS OF USING AND FORMING EDUCATIONAL RECOURCES OF INNOVATIVE COMPUTER DIDACTICS

    Directory of Open Access Journals (Sweden)

    Grishchenko V. I.

    2015-09-01

    Full Text Available The article contains the schemes of forming theoretical models which illustrate the processes of ERICD’s (educational resources of innovative computer didactics application in the professional work of educational specialists, as well as forming them on the basis of elaborated software components. We offer the three models which give to educational specialists the references for well-grounded choice of ERICD, for forming electronic learning resources according to the requirements of Federal Standard, for generating new types of resource

  16. Utilization of CO2 and biomass char derived from pyrolysis of Dunaliella salina: the effects of steam and catalyst on CO and H2 gas production.

    Science.gov (United States)

    Yang, Chao; Jia, Lishan; Su, Shuai; Tian, Zhongbiao; Song, Qianqian; Fang, Weiping; Chen, Changping; Liu, Guangfa

    2012-04-01

    Biomass char, by-product of Dunaliella salina pyrolysis at a final pyrolysis temperature of 500°C, was used as feedstock material in this study. The reactions of biomass char with CO(2) were performed in a fixed-bed reactor to evaluate the effect of temperature and steam on the CO(2) conversion, CO yield and gas composition. The CO(2) conversion and CO yield without steam and catalyst reached about 61.84% and 0.99mol/(mol CO(2)) at 800°C, respectively. Steam and high temperature led to high CO(2) conversion. A new approach for improving H(2) was carried out by using biomass char and Au/Al(2)O(3) catalyst, which combined steam gasification of biomass char and water gas shift reaction, and the H(2) concentration was 1.8 times higher than without catalyst. The process not only mitigated CO(2) emission and made use of residual biomass char, but also created renewable source.

  17. Modeling of Heat Transfer and Solidification Process of Spray Formed Billet

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    In this paper, modeling of heat transfer and solidification process of spray formed billet was established. Thermal profiles of billet at various spray time and under various spray forming conditions were calculated numerically. The simulation results are consistent with the actual experimental results.

  18. Simulating Some Complex Phenomena in Hydrothermal Ore-Forming Processes by Reaction-Diffusion CNN

    Institute of Scientific and Technical Information of China (English)

    Xu Deyi; Yu Chongwen; Bao Zhengyu

    2003-01-01

    Complexity phenomena like dynamic and static patterns, order from disorder, chaos and catastrophe were simulated by the application of 2-D reaction-diffusion CNN of two state variables and two diffusion coefficients transformed from Zhabotinksii model. They revealed somehow the mechanism of hydrothermal ore-forming processes, and answered several questions about the onset of ore forming.

  19. Microstructures of Melt-Processed and Spark Plasma Sintered Ceramic Waste Forms

    Science.gov (United States)

    Clark, B. M.; Tumurugoti, P.; Sundaram, S. K.; Amoroso, J. W.; Marra, J. C.; Brinkman, K. S.

    2014-12-01

    Hollandite-rich ceramic waste forms have been demonstrated to exhibit high durability while simultaneously accommodating a wide range of radionuclides in their matrices. This paper presents preliminary results on the preparation and characterization of ceramic waste forms prepared by two different methods—melt processing and spark plasma sintering (SPS). Both processes resulted in similar phase assemblages but exhibited different microstructures depending on processing method. The SPS samples exhibited fine-grained (<1 µm) and dispersed phases, whereas the melt-processed sample contained larger grains (10-20 µm) of specific phases. Additional data will need to be collected on the aqueous leaching durability and radiation resistance to evaluate each processing method for waste form performance.

  20. COUPLED ATOMIZATION AND SPRAY MODELLING IN THE SPRAY FORMING PROCESS USING OPENFOAM

    DEFF Research Database (Denmark)

    Gjesing, Rasmus; Hattel, Jesper Henri; Fritsching, Udo

    2009-01-01

    The paper presents a numerical model capable of simulating the atomization, break-up and in-flight spray phenomena in the spray forming process. The model is developed and implemented in the freeware code openFOAM. The focus is on studying the coupling effect of the melt break-up phenomena with the...... model for droplet cooling and solidification. The model is tested and validated against results from literature and experiments. Subsequently, the model is used to simulate the complex flow fields in the spray forming process and the results are discussed. The presented model of the spray forming...... process is able to predict the droplet size distribution of the spray from the process conditions, by introducing submodels for the melt fragmentation and successive secondary break-up processes as part of the spray model. Furthermore, the competition of drop break-up and solidification is derived by...

  1. Process for making RF shielded cable connector assemblies and the products formed thereby

    Science.gov (United States)

    Fisher, A.; Clatterbuck, C. H. (Inventor)

    1973-01-01

    A process for making RF shielded cable connector assemblies and the resulting structures is described. The process basically consists of potting wires of a shielded cable between the cable shield and a connector housing to fill in, support, regidize, and insulate the individual wires contained in the cable. The formed potting is coated with an electrically conductive material so as to form an entirely encompassing adhering conductive path between the cable shield and the metallic connector housing. A protective jacket is thereby formed over the conductive coating between the cable shield and the connector housing.

  2. Numerical simulation of wrinkle phenomenon during multi-point forming process of shallow rectangle cup

    Institute of Scientific and Technical Information of China (English)

    裴永生; 李明哲; 李雪; 隋振

    2004-01-01

    In this paper, the principle of multi-point forming (MPF) technique is presented. One of the most serious defects, wrinkling, during the multi-point forming process of a shallow rectangle cup is discussed by means of numerical simulation on the shallow rectangle cup forming process. The effects of thickness, material of sheet metal and the pressure of the blank holder are investigated. Based on the simulation results, the reasons and control methods of wrinkling are pointed out. Moreover, the experiment on the multi-point die forming of the shallow rectangle cup by the MPF machine is done to validate the efficiency of the numerical simulation,and the result proves that the application of an elastic cushion in the forming can restrain wrinkling efficiently.

  3. Numerical Simulation of the Roll Forming Process of Aluminum Folded Micro-channel Tube

    Science.gov (United States)

    Zou, Tianxia; Zhou, Ning; Peng, Yinghong; Tang, Ding; Li, Dayong

    2016-08-01

    Micro-channel tube is the most important component of flat tube heat exchangers. The folded microchannel tube is made of clad aluminum sheet through roll forming process, and has great advantage in the aspect of corrosion resistance over extruded tube. The folded tube's sub-millimeter channel size as well as tight dimensional precision requirement brings great challenge to roll forming process design. In this paper, the finite element model of the whole roll forming process of a ten-channel tube is established by using ABAQUS/Explicit. The deformation at different forming stands are investigated and compared with experiment. The hydraulic pressure test is carried out on the developed tube and its pressure bearing capacity is evaluated.

  4. Morphological changes during oxidation of a single char particle

    Energy Technology Data Exchange (ETDEWEB)

    d' Amore, M. (Salerno Univ. (Italy). Dept. of Chemical and Food Engineering); Tognotti, L. (Pisa Univ. (Italy). Dept. of Chemical Engineering); Sarofim, A.F. (Massachusetts Inst. of Tech., Cambridge, MA (United States). Dept. of Chemical Engineering)

    1992-01-01

    In this study, the changes with conversion in morphology of a carbon char in the temperature range 500--1200 K are followed by using an electrodynamic balance (EDB) (Spjut et al., 1985; Dudek, 1988; Bar-ziv et al., 1989). This device allows one to measure in situ, over temperature range wider than in other apparatuses, mass, diameter, density, surface area, rate of reaction and temperature for a single, suspended submillimeter particle. By following with the EDB the changes in the char as it reacts, it is possible to study the influence of the porous texture on the reaction behavior and shed some light on the contribution by micropores to the reaction in the chemical kinetic controlled regime.

  5. High energy density processing of a free form nickel-alumina nanocomposite

    NARCIS (Netherlands)

    Viswanathan, V; Agarwal, A; Ocelik, V; De Hosson, J T M; Sobczak, N; Seal, S

    2006-01-01

    The development of a free form bulk Nickel reinforced Alumina matrix nano composites using Air Plasma Spray and laser processing has been presented. The process consumes less time and requires further minimal machining and therefore is cost effective. The relative differences in using APS over laser

  6. Reliability Estimation of the Pultrusion Process Using the First-Order Reliability Method (FORM)

    NARCIS (Netherlands)

    Baran, Ismet; Tutum, Cem C.; Hattel, Jesper H.

    2013-01-01

    In the present study the reliability estimation of the pultrusion process of a flat plate is analyzed by using the first order reliability method (FORM). The implementation of the numerical process model is validated by comparing the deterministic temperature and cure degree profiles with correspond

  7. Process optimisation in the semi-solid forming of hypereutectic Al/Si MMCs

    OpenAIRE

    Ward, P; Atkinson, H; D. Kirkwood; Sellars, C.

    1993-01-01

    A novel processing route for the fabrication of Al/high silicon MMCs is presented. The silicon size is much finer than can be achieved by casting, yet the materials can still be formed into a near-net shape. Initial properties of the MMCs are presented, and methods under investigation to optimise processing and improve properties are discussed.

  8. Methodology development for the sustainability process assessment of sheet metal forming of complex-shaped products

    Science.gov (United States)

    Pankratov, D. L.; Kashapova, L. R.

    2015-06-01

    A methodology was developed for automated assessment of the reliability of the process of sheet metal forming process to reduce the defects in complex components manufacture. The article identifies the range of allowable values of the stamp parameters to obtain defect-free punching of spars trucks.

  9. /sup 238/Pu fuel form processes quarterly report, April-June 1980

    Energy Technology Data Exchange (ETDEWEB)

    Folger, R. L.

    1980-06-01

    Savannah River Laboratory (SRL) completed the development of a production process to fabricate /sup 238/PuO/sub 2/ fuel forms for the GPHS. The fabrication flowsheet was based on a flowsheet originally developed at Los Alamos National Scientific Laboratory (LANSL). A summary report of the SRL process development effort is presented.

  10. Form cues and content difficulty as determinants of children's cognitive processing of televised educational messages.

    Science.gov (United States)

    Campbell, T A; Wright, J C; Huston, A C

    1987-06-01

    An experiment was designed to assess the effects of formal production features and content difficulty on children's processing of televised messages about nutrition. Messages with identical content (the same script and visual shot sequence) were made in two forms: child program forms (animated film, second-person address, and character voice narration with sprightly music) and adult program forms (live photography, third-person address, and adult male narration with sedate background music). For each form, messages were made at three levels of content difficulty. Easier versions were longer, more redundant, and used simpler language; difficult versions presented information more quickly with less redundancy and more abstract language. Regardless of form or difficulty level, each set of bits presented the same basic information. Kindergarten children (N = 120) were assigned to view three different bits of the same form type and difficulty embedded in a miniprogram. Visual attention to child forms was significantly greater than to adult forms; free and cued recall scores were also higher for child than for adult forms. Although all recall and recognition scores were best for easy versions and worst for difficult versions, attention showed only minor variation as a function of content difficulty. Results are interpreted to indicate that formal production features, independently of content, influence the effort and level of processing that children use to understand televised educational messages.

  11. Investigation of the deformation stability in the incremental sheet forming process

    Directory of Open Access Journals (Sweden)

    Ai S.

    2015-01-01

    Full Text Available Incremental sheet forming (ISF is a highly versatile and flexible process for rapid manufacturing of complex sheet metal parts. One of the unique characters of the ISF process is the improved formability comparing to conventional sheet forming process. This may be due to the localized deformation nature, which increases the deformation stability in the ISF process. Although many hypotheses have been proposed, there is no direct modelling and calculation of the ISF deformation stability. Aiming to obtain a better understanding of the ISF process, an analytical model was developed to investigate and analyse the material deformation stability in this work. Based on the analytical evaluation of stress variations and force equilibrium, a mathematical relationship between the maximum forming angle and the process stability condition was established. To validate the developed model, experiments were carried out by forming a hyperbolic part made of AA1100 material. The maximum forming angle, as an indicator to the ISF formability, was employed compare the analytical evaluation and experimental result. It was found that the ISF deformation stability is one of the key factors that affect the ISF formability.

  12. Rapid Forming Process and Device of Small-size Booster Explosive Pellet

    Institute of Scientific and Technical Information of China (English)

    MA Gui-chun; ZHANG Shu-sheng; ZHANG Jing-lin; ZHI Hai-bo

    2006-01-01

    A rapid forming device for small-size booster explosive pellet is designed. The rationality of explosive processing is analyzed in theory and the realized process is presented. The experimental results show that the device can improve the internal quality of small-size explosive pellet and the obtained pellet has a good density distribution. The presented rapid forming process and device can provide a credible base for the precise testing and application of booster explosive to general weapons, aerospace and aeronautic weapons and nukes.

  13. Phosphorus Availability in Soils Amended with Wheat Residue Char

    OpenAIRE

    Parvage, Md. Masud; Ulén, Barbro; Eriksson, Jan; Strock, Jeffery; Kirchmann, Holger

    2013-01-01

    Plant availability and risk for leaching and/or runoff losses of phosphorus (P) from soils depends among others on P concentration in the soil solution. Water soluble P in soil measures soil solution P concentration. The aim of this study was to understand the effect of wheat residue char (biochar) addition on water soluble P concentration in a wide range of biochar amended soils. Eleven agricultural fields representing dominant soil texture classes of Swedish agricultural lands were chosen. ...

  14. BONE CHAR BASED BUCKET DEFLUORIDATOR IN TANZANIAN HOUSEHOLDS

    DEFF Research Database (Denmark)

    Jacobsen, P.; Dahi, Elian

    1997-01-01

    A household defluoridator, made of a 20 L plastic bucket and 10 kg of bone char, is tested and found efficient to remove fluoride at a capacity of 1.1 mg/g. On an average, the defluoridator reduced the original contents of 8.5 mgF/L to 0.37 mgF/L, i.e. 95.6 %, for a period of 2 months, where 32.5...

  15. Industrial application and validation of forming simulation in the flexforming process

    Science.gov (United States)

    Leacock, Alan; Ling, Dave; Bergkvist, Mikael

    2016-08-01

    The flex-forming process is used extensively in aerospace industry for net shape forming of sheet metal structural components. Common metals used in the manufacture of these components include 7075 and 2024 aluminium alloys; usually in an as quenched condition following solution heat treatment. While the process is commonplace, the level of manual rework remains high, driven by inherent process and material variability and the lack of upfront analysis before the manufacture of tooling. A suitable process modelling method using AutoForm is presented along with an industrial validation study for the manufacture of an aerospace frame component in 7075-W aluminium alloy. The results illustrate the importance of material model accuracy and the inclusion of through thickness compressive stresses in predicting the flange springback of the component.

  16. Structure-Based Predictive model for Coal Char Combustion.

    Energy Technology Data Exchange (ETDEWEB)

    Hurt, R.; Colo, J [Brown Univ., Providence, RI (United States). Div. of Engineering; Essenhigh, R.; Hadad, C [Ohio State Univ., Columbus, OH (United States). Dept. of Chemistry; Stanley, E. [Boston Univ., MA (United States). Dept. of Physics

    1997-09-24

    During the third quarter of this project, progress was made on both major technical tasks. Progress was made in the chemistry department at OSU on the calculation of thermodynamic properties for a number of model organic compounds. Modelling work was carried out at Brown to adapt a thermodynamic model of carbonaceous mesophase formation, originally applied to pitch carbonization, to the prediction of coke texture in coal combustion. This latter work makes use of the FG-DVC model of coal pyrolysis developed by Advanced Fuel Research to specify the pool of aromatic clusters that participate in the order/disorder transition. This modelling approach shows promise for the mechanistic prediction of the rank dependence of char structure and will therefore be pursued further. Crystalline ordering phenomena were also observed in a model char prepared from phenol-formaldehyde carbonized at 900{degrees}C and 1300{degrees}C using high-resolution TEM fringe imaging. Dramatic changes occur in the structure between 900 and 1300{degrees}C, making this char a suitable candidate for upcoming in situ work on the hot stage TEM. Work also proceeded on molecular dynamics simulations at Boston University and on equipment modification and testing for the combustion experiments with widely varying flame types at Ohio State.

  17. Vitality Forms Processing in the Insula during Action Observation: A Multivoxel Pattern Analysis.

    Science.gov (United States)

    Di Cesare, Giuseppe; Valente, Giancarlo; Di Dio, Cinzia; Ruffaldi, Emanuele; Bergamasco, Massimo; Goebel, Rainer; Rizzolatti, Giacomo

    2016-01-01

    Observing the style of an action done by others allows the observer to understand the cognitive state of the agent. This information has been defined by Stern "vitality forms". Previous experiments showed that the dorso-central insula is selectively active both during vitality form observation and execution. In the present study, we presented participants with videos showing hand actions performed with different velocities and asked them to judge either their vitality form (gentle, neutral, rude) or their velocity (slow, medium, fast). The aim of the present study was to assess, using multi-voxel pattern analysis, whether vitality forms and velocities of observed goal-directed actions are differentially processed in the insula, and more specifically whether action velocity is encoded per se or it is an element that triggers neural populations of the insula encoding the vitality form. The results showed that, consistently across subjects, in the dorso-central sector of the insula there were voxels selectively tuned to vitality forms, while voxel tuned to velocity were rare. These results indicate that the dorso-central insula, which previous data showed to be involved in the vitality form processing, contains voxels specific for the action style processing.

  18. A comparison of form processing involved in the perception of biological and nonbiological movements

    Science.gov (United States)

    Thurman, Steven M.; Lu, Hongjing

    2016-01-01

    Although there is evidence for specialization in the human brain for processing biological motion per se, few studies have directly examined the specialization of form processing in biological motion perception. The current study was designed to systematically compare form processing in perception of biological (human walkers) to nonbiological (rotating squares) stimuli. Dynamic form-based stimuli were constructed with conflicting form cues (position and orientation), such that the objects were perceived to be moving ambiguously in two directions at once. In Experiment 1, we used the classification image technique to examine how local form cues are integrated across space and time in a bottom-up manner. By comparing with a Bayesian observer model that embodies generic principles of form analysis (e.g., template matching) and integrates form information according to cue reliability, we found that human observers employ domain-general processes to recognize both human actions and nonbiological object movements. Experiments 2 and 3 found differential top-down effects of spatial context on perception of biological and nonbiological forms. When a background does not involve social information, observers are biased to perceive foreground object movements in the direction opposite to surrounding motion. However, when a background involves social cues, such as a crowd of similar objects, perception is biased toward the same direction as the crowd for biological walking stimuli, but not for rotating nonbiological stimuli. The model provided an accurate account of top-down modulations by adjusting the prior probabilities associated with the internal templates, demonstrating the power and flexibility of the Bayesian approach for visual form perception. PMID:26746875

  19. Forming Process of Strong Anisotropic Material Based on the Hydrodynamic Deep Drawing with Radial Pressure

    Institute of Scientific and Technical Information of China (English)

    Lihui LANG; Joachim DANCKERT; Karl Brian NIELSEN

    2005-01-01

    The hydrodynamic deep drawing process enables net shape or near net shape forming of complicated sheet metal parts made from difficultly forming materials, such as aluminium or high strength steels. Based on the conventional hydrodynamic deep drawing process, a new process, hydrodynamic deep drawing process, in which radial pressure is applied to the rim of the blank, is proposed. This new process has been analysed using FEM simulations and the obtained results have been compared with the experimental results. The material used in the experiments was Al-Mg-Si alloy, and in the FEM-simulations the elastic-plastic behaviour of Al-Mg-Si alloy was modelled using Barlat's 89 yield criteria.

  20. When semantics aids phonology: A processing advantage for iconic word forms in aphasia.

    Science.gov (United States)

    Meteyard, Lotte; Stoppard, Emily; Snudden, Dee; Cappa, Stefano F; Vigliocco, Gabriella

    2015-09-01

    Iconicity is the non-arbitrary relation between properties of a phonological form and semantic content (e.g. "moo", "splash"). It is a common feature of both spoken and signed languages, and recent evidence shows that iconic forms confer an advantage during word learning. We explored whether iconic forms conferred a processing advantage for 13 individuals with aphasia following left-hemisphere stroke. Iconic and control words were compared in four different tasks: repetition, reading aloud, auditory lexical decision and visual lexical decision. An advantage for iconic words was seen for some individuals in all tasks, with consistent group effects emerging in reading aloud and auditory lexical decision. Both these tasks rely on mapping between semantics and phonology. We conclude that iconicity aids spoken word processing for individuals with aphasia. This advantage is due to a stronger connection between semantic information and phonological forms. PMID:25637775

  1. When semantics aids phonology: A processing advantage for iconic word forms in aphasia.

    Science.gov (United States)

    Meteyard, Lotte; Stoppard, Emily; Snudden, Dee; Cappa, Stefano F; Vigliocco, Gabriella

    2015-09-01

    Iconicity is the non-arbitrary relation between properties of a phonological form and semantic content (e.g. "moo", "splash"). It is a common feature of both spoken and signed languages, and recent evidence shows that iconic forms confer an advantage during word learning. We explored whether iconic forms conferred a processing advantage for 13 individuals with aphasia following left-hemisphere stroke. Iconic and control words were compared in four different tasks: repetition, reading aloud, auditory lexical decision and visual lexical decision. An advantage for iconic words was seen for some individuals in all tasks, with consistent group effects emerging in reading aloud and auditory lexical decision. Both these tasks rely on mapping between semantics and phonology. We conclude that iconicity aids spoken word processing for individuals with aphasia. This advantage is due to a stronger connection between semantic information and phonological forms.

  2. Free-form architectural envelopes: Digital processes opportunities of industrial production at a reasonable price

    Directory of Open Access Journals (Sweden)

    E. Castaneda

    2015-06-01

    Full Text Available Free-form architecture is one of the major challenges for architects, engineers, and the building industry. This is due to the inherent difficulty of manufacturing double curvature facades at reasonable prices and quality. This paper discusses the possibilities of manufacturing free-form facade panels for architectural envelopes supported by recent advances in CAD/CAM systems and digital processes. These methods allow for no-mould processes, thus reducing the final price. Examples of actual constructions will be presented to prove the viability of computer numerically controlled (CNC fabrication technologies. Scientific literature will be reviewed. Promising fabrication methods (additive, subtractive, forming to accomplish this proposal will be discussed. This research will provide valuable information regarding the feasibility of manufacturing free-form panels for architectural envelopes at lower prices.  

  3. Robust Design of Sheet Metal Forming Process Based on Kriging Metamodel

    Science.gov (United States)

    Xie, Yanmin

    2011-08-01

    Nowadays, sheet metal forming processes design is not a trivial task due to the complex issues to be taken into account (conflicting design goals, complex shapes forming and so on). Optimization methods have also been widely applied in sheet metal forming. Therefore, proper design methods to reduce time and costs have to be developed mostly based on computer aided procedures. At the same time, the existence of variations during manufacturing processes significantly may influence final product quality, rendering non-robust optimal solutions. In this paper, a small size of design of experiments is conducted to investigate how a stochastic behavior of noise factors affects drawing quality. The finite element software (LS_DYNA) is used to simulate the complex sheet metal stamping processes. The Kriging metamodel is adopted to map the relation between input process parameters and part quality. Robust design models for sheet metal forming process integrate adaptive importance sampling with Kriging model, in order to minimize impact of the variations and achieve reliable process parameters. In the adaptive sample, an improved criterion is used to provide direction in which additional training samples can be added to better the Kriging model. Nonlinear functions as test functions and a square stamping example (NUMISHEET'93) are employed to verify the proposed method. Final results indicate application feasibility of the aforesaid method proposed for multi-response robust design.

  4. Sustainable development of tyre char-based activated carbons with different textural properties for value-added applications.

    Science.gov (United States)

    Hadi, Pejman; Yeung, Kit Ying; Guo, Jiaxin; Wang, Huaimin; McKay, Gordon

    2016-04-01

    This paper aims at the sustainable development of activated carbons for value-added applications from the waste tyre pyrolysis product, tyre char, in order to make pyrolysis economically favorable. Two activation process parameters, activation temperature (900, 925, 950 and 975 °C) and residence time (2, 4 and 6 h) with steam as the activating agent have been investigated. The textural properties of the produced tyre char activated carbons have been characterized by nitrogen adsorption-desorption experiments at -196 °C. The activation process has resulted in the production of mesoporous activated carbons confirmed by the existence of hysteresis loops in the N2 adsorption-desorption curves and the pore size distribution curves obtained from BJH method. The BET surface area, total pore volume and mesopore volume of the activated carbons from tyre char have been improved to 732 m(2)/g, 0.91 cm(3)/g and 0.89 cm(3)/g, respectively. It has been observed that the BET surface area, mesopore volume and total pore volume increased linearly with burnoff during activation in the range of experimental parameters studied. Thus, yield-normalized surface area, defined as the surface area of the activated carbon per gram of the precursor, has been introduced to optimize the activation conditions. Accordingly, the optimized activation conditions have been demonstrated as an activation temperature of 975 °C and an activation time of 4 h. PMID:26775155

  5. The Blurred Line between Form and Process: A Comparison of Stream Channel Classification Frameworks.

    Directory of Open Access Journals (Sweden)

    Alan Kasprak

    Full Text Available Stream classification provides a means to understand the diversity and distribution of channels and floodplains that occur across a landscape while identifying links between geomorphic form and process. Accordingly, stream classification is frequently employed as a watershed planning, management, and restoration tool. At the same time, there has been intense debate and criticism of particular frameworks, on the grounds that these frameworks classify stream reaches based largely on their physical form, rather than direct measurements of their component hydrogeomorphic processes. Despite this debate surrounding stream classifications, and their ongoing use in watershed management, direct comparisons of channel classification frameworks are rare. Here we implement four stream classification frameworks and explore the degree to which each make inferences about hydrogeomorphic process from channel form within the Middle Fork John Day Basin, a watershed of high conservation interest within the Columbia River Basin, U.S.A. We compare the results of the River Styles Framework, Natural Channel Classification, Rosgen Classification System, and a channel form-based statistical classification at 33 field-monitored sites. We found that the four frameworks consistently classified reach types into similar groups based on each reach or segment's dominant hydrogeomorphic elements. Where classified channel types diverged, differences could be attributed to the (a spatial scale of input data used, (b the requisite metrics and their order in completing a framework's decision tree and/or, (c whether the framework attempts to classify current or historic channel form. Divergence in framework agreement was also observed at reaches where channel planform was decoupled from valley setting. Overall, the relative agreement between frameworks indicates that criticism of individual classifications for their use of form in grouping stream channels may be overstated. These

  6. The Blurred Line between Form and Process: A Comparison of Stream Channel Classification Frameworks

    Science.gov (United States)

    Kasprak, Alan; Hough-Snee, Nate

    2016-01-01

    Stream classification provides a means to understand the diversity and distribution of channels and floodplains that occur across a landscape while identifying links between geomorphic form and process. Accordingly, stream classification is frequently employed as a watershed planning, management, and restoration tool. At the same time, there has been intense debate and criticism of particular frameworks, on the grounds that these frameworks classify stream reaches based largely on their physical form, rather than direct measurements of their component hydrogeomorphic processes. Despite this debate surrounding stream classifications, and their ongoing use in watershed management, direct comparisons of channel classification frameworks are rare. Here we implement four stream classification frameworks and explore the degree to which each make inferences about hydrogeomorphic process from channel form within the Middle Fork John Day Basin, a watershed of high conservation interest within the Columbia River Basin, U.S.A. We compare the results of the River Styles Framework, Natural Channel Classification, Rosgen Classification System, and a channel form-based statistical classification at 33 field-monitored sites. We found that the four frameworks consistently classified reach types into similar groups based on each reach or segment’s dominant hydrogeomorphic elements. Where classified channel types diverged, differences could be attributed to the (a) spatial scale of input data used, (b) the requisite metrics and their order in completing a framework’s decision tree and/or, (c) whether the framework attempts to classify current or historic channel form. Divergence in framework agreement was also observed at reaches where channel planform was decoupled from valley setting. Overall, the relative agreement between frameworks indicates that criticism of individual classifications for their use of form in grouping stream channels may be overstated. These form

  7. Mathematical Modeling of Impulsive Forming Processes Using Various Energy Sources and Transmitting Medium

    OpenAIRE

    Sabelkin, V.; Taran, V.; Vovk, A.; V. Vovk

    2006-01-01

    High-speed forming uses high explosives, gun powder, combustible gas mixes and compressed gases as sources of energy. Special mathematical models are used to take into account specific dynamic properties. Different technological processes of forming have been modeled in the work. They use liquid (water), elastic (polyurethane), and gaseous transmitting medium. The difference between impulse energy transference, load distribution on a blank and tool surface, and also wave propagation is sho...

  8. Rapid Finite Element Analysis of Bulk Metal Forming Process Based on Deformation Theory

    Institute of Scientific and Technical Information of China (English)

    WANG Peng; DONG Xiang-huai; FU Li-jun

    2009-01-01

    The one-step finite element method (FEM), based on plastic deformation theory, has been widely used to simulate sheet metal forming processes, but its application in bulk metal forming simulation has been seldom investigated, because of the complexity involved. Thus, a bulk metal forming process was analyzed using a rapid FEM based on deformation theory. The material was assumed to be rigid-plastic and strain-hardened. The constitutive relationship between stress and total strain was adopted, whereas the incompressible condition was enforced by penalty function. The geometrical non-linearity in large plastic deformation was taken into consideration. Furthermore, the force boundary condition was treated by a simplified equivalent approach, considering the contact history. Based on constraint variational principle, the deformation FEM was proposed. The one-step forward simulation of axisymmetric upsetting process was performed using this method. The results were compared with those obtained by the traditional incremental FEM to verify the feasibility of the proposed method.

  9. Finite element synthesized analysis of the forming process of spiral welded pipe

    Institute of Scientific and Technical Information of China (English)

    Yu Jianrong; Wu Bo; Zhao Zenghui; Ling Xingzhong; Xiao Yunfeng; Chen Haiyang

    2006-01-01

    Numerical simulation concerning the forming and welding process of spiral welded pipe was conducted, which included three steps: the first step was the stress analysis when the spiral was formed, and then the stress was regarded as initial condition of melding during the temperature field analysis in the process of welding, the last step was the thermal stress analysis of the weld seam after the welding was over. Moreover, when the steel strip was pushed, the stress was also calculated by non-linearity contact technology using Abaqus Software. By finite element modeling and calculating of the forming and welding process of the spiral welded pipe, the key points of the multi-fields synthetic simulating were studied and discussed.

  10. Advanced char burnout models for the simulation of pulverized coal fired boilers

    Energy Technology Data Exchange (ETDEWEB)

    T. Severin; S. Wirtz; V. Scherer [Ruhr-University, Bochum (Germany). Institute of Energy Plant Technology (LEAT)

    2005-07-01

    The numerical simulation of coal combustion processes is widely used as an efficient means to predict burner or system behaviour. In this paper an approach to improve CFD simulations of pulverized coal fired boilers with advanced coal combustion models is presented. In simple coal combustion models, first order Arrhenius rate equations are used for devolatilization and char burnout. The accuracy of such simple models is sufficient for the basic aspects of heat release. The prediction of carbon-in-ash is one aspect of special interest in the simulation of pulverized coal fired boilers. To determine the carbon-in-ash levels in the fly ash of coal fired furnaces, the char burnout model has to be more detailed. It was tested, in how far changing operating conditions affect the carbon-in-ash prediction of the simulation. To run several test cases in a short time, a simplified cellnet model was applied. To use a cellnet model for simulations of pulverized coal fired boilers, it was coupled with a Lagrangian particle model, used in CFD simulations, too. 18 refs., 5 figs., 5 tabs.

  11. Inverse estimation of properties for charring material using a hybrid genetic algorithm

    International Nuclear Information System (INIS)

    Fire characteristics can be analyzed more realistically by using more accurate material properties related to the fire dynamics and one way to acquire these fire properties is to use one of the inverse property estimation techniques. In this study an optimization algorithm which is frequently applied for the inverse heat transfer problems is selected to demonstrate the procedure of obtaining fire properties of a solid charring material with relatively simple chemical structure. Thermal decomposition is occurred at the surface of the test plate by receiving the radiative energy from external heat sources and in this process the heat transfer through the test plate can be simplified by an unsteady one dimensional problem. The input parameters for the analyses are the surface temperature and mass loss rate of the char plate which are determined from the actual experiment of from the unsteady one-dimensional analysis with a given set of eight properties. The performance of hybrid genetic algorithm (HGA) is compare with a basic genetic algorithm (GA) in order to examine its performance. This comparison is carried out for the inverse property problem of estimating the fire properties related to the reaction pyrolysis of some relatively simple materials; redwood and red oak. Results show that the hybrid genetic algorithm has better performance in estimating the eight pyrolysis properties than the genetic algorithm

  12. Bone char surface modification by nano-gold coating for elemental mercury vapor removal

    Science.gov (United States)

    Assari, Mohamad javad; Rezaee, Abbas; Rangkooy, Hossinali

    2015-07-01

    The present work was done to develop a novel nanocomposite using bone char coated with nano-gold for capture of elemental mercury (Hg0) from air. The morphologies, structures, and chemical constitute of the prepared nanocomposite were evaluated by UV-VIS-NIR, dynamic light-scattering (DLS), X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infra-red (FTIR) spectroscopy, and energy dispersive X-ray spectroscopy (EDS). The capture performance of nanocomposite was evaluated in a needle trap for mercury vapor. An on-line setup based on cold vapor atomic absorption spectrometry (CVAAS) was designed for Hg0 determination. Dynamic capacity of nanocomposite for Hg0 was shown high efficient operating capacity of 586.7 μg/g. As temperature increases, the dynamic adsorption capacity of the nanocomposite was decreased, which are characteristics of physicosorption processes. It was found that the surface modification of bone char with nano-gold has various advantages such as high operating dynamic adsorption capacity and low cost preparation. It was also demonstrated that the developed nanocomposite is suitable for on-line monitoring of Hg0. It could be applied for the laboratory and field studies.

  13. Vitality Forms Processing in the Insula during Action Observation: A Multivoxel Pattern Analysis

    Science.gov (United States)

    Di Cesare, Giuseppe; Valente, Giancarlo; Di Dio, Cinzia; Ruffaldi, Emanuele; Bergamasco, Massimo; Goebel, Rainer; Rizzolatti, Giacomo

    2016-01-01

    Observing the style of an action done by others allows the observer to understand the cognitive state of the agent. This information has been defined by Stern “vitality forms”. Previous experiments showed that the dorso-central insula is selectively active both during vitality form observation and execution. In the present study, we presented participants with videos showing hand actions performed with different velocities and asked them to judge either their vitality form (gentle, neutral, rude) or their velocity (slow, medium, fast). The aim of the present study was to assess, using multi-voxel pattern analysis, whether vitality forms and velocities of observed goal-directed actions are differentially processed in the insula, and more specifically whether action velocity is encoded per se or it is an element that triggers neural populations of the insula encoding the vitality form. The results showed that, consistently across subjects, in the dorso-central sector of the insula there were voxels selectively tuned to vitality forms, while voxel tuned to velocity were rare. These results indicate that the dorso-central insula, which previous data showed to be involved in the vitality form processing, contains voxels specific for the action style processing. PMID:27375461

  14. Plasma Processes : Operation of a capacitor bank for plasma metal forming

    Indian Academy of Sciences (India)

    P Sarkar; S Chaturvedi; Raj Kumar; Rajesh Kumar; D Lathi; A Shyam; J Sonara

    2000-11-01

    Previously metal forming has been done using electromagnet in pulsed power mode, better known as magneform [1]. Here we will be presenting a different technique for metal forming. We are using water as a medium for this process. By discharging the stored electrical energy of the capacitor bank in water, we are getting the desired result i.e. to form (expand or compress) a wide range of workpiece to the desired shapes. The advantage of this method over conventional method is that it uses low power (negligible running cost). It does not require any post assembly cleaning degreasing and is hence environmentally ‘friendly’.

  15. Electromagnetic and absorbing property of CIPs/resin composite using the 3D forming process

    Science.gov (United States)

    Xu, Yonggang; Liang, Zichang; Wang, Xiaobing; Yuan, Liming; Li, Xinghao

    2016-08-01

    The absorbing composite filled with the flaky carbonyl iron particles (CIPs) were prepared using a three-dimensional (3D) forming process, in which the forming powder was fabricated using a milling process. The surface morphology was characterized by the scanning electron microscopy, the static magnetic property was evaluated on a vibrating sample magnetometer, and X-ray diffraction (XRD) patterns were done to analyze the particle crystal grain structure. The complex permittivity and permeability were measured using a vector network analyzer in the frequency range of 4-18 GHz. With the variable thickness was set, the reflection loss (RL) was simulated to analyze the absorbing property of the composite. The results showed that the forming powder was uniformly dispersed in the absorber, and the saturation magnetization and the grain structure of the CIPs in the forming powder nearly did not change in the milling process. With the same volume content CIPs added, the average permittivity and the imaginary permeability of the samples added the powder was smaller than the directly mixing sample due to the aggregation effect. The RL results showed that the absorbing composites using the 3D forming process with thickness 6 or 8 mm had an better absorbing property (minimum RL -13.58 and -21.85 dB) in 4-18 GHz.

  16. Coal combustion science: Task 1, Coal char combustion: Task 2, Fate of mineral matter. Quarterly progress report, July--September 1993

    Energy Technology Data Exchange (ETDEWEB)

    Hardesty, D.R. [ed.; Hurt, R.H.; Davis, K.A.; Baxter, L.L.

    1994-07-01

    Progress reports are presented for the following tasks: (1) kinetics and mechanisms of pulverized coal char combustion and (2) fate of inorganic material during coal combustion. The objective of Task 1 is to characterize the combustion behavior of selected US coals under conditions relevant to industrial pulverized coal-fired furnaces. In Sandia`s Coal Combustion Laboratory (CCL), optical techniques are used to obtain high-resolution images of individual burning coal char particles and to measure, in situ, their temperatures, sizes, and velocities. Detailed models of combustion transport processes are then used to determine kinetic parameters describing the combustion behavior as a function of coal type and combustion environment. Partially reacted char particles are also sampled and characterized with advanced materials diagnostics to understand the critical physical and chemical transformations that influence reaction rates and burnout times. The ultimate goal of the task is the establishment of a data base of the high temperature reactivities of chars from strategic US coals, from which important trends may be identified and predictive capabilities developed. The overall objectives for task 2 are: (1) to complete experimental and theoretical investigation of ash release mechanisms; (2) to complete experimental work on char fragmentation; (3) to establish the extent of coal (as opposed to char) fragmentation as a function of coal type and particle size; (4) to develop diagnostic capabilities for in situ, real-time, qualitative indications of surface species composition during ash deposition, with work continuing into FY94; (5) to develop diagnostic capabilities for in situ, real-time qualitative detection of inorganic vapor concentrations; and (6) to conduct a literature survey on the current state of understanding of ash deposition, with work continuing into FY94.

  17. Process description and plant design for preparing ceramic high-level waste forms

    International Nuclear Information System (INIS)

    The ceramics process flow diagram has been simplified and upgraded to utilize only two major processing steps - fluid-bed calcination and hot isostatic press consolidating. Full-scale fluid-bed calcination has been used at INEL to calcine high-level waste for 18 y; and a second-generation calciner, a fully remotely operated and maintained calciner that meets ALARA guidelines, started calcining high-level waste in 1982. Full-scale hot isostatic consolidation has been used by DOE and commercial enterprises to consolidate radioactive components and to encapsulate spent fuel elements for several years. With further development aimed at process integration and parametric optimization, the operating knowledge of full-scale demonstration of the key process steps should be rapidly adaptable to scale-up of the ceramic process to full plant size. Process flowsheets used to prepare ceramic and glass waste forms from defense and commercial high-level liquid waste are described. Preliminary layouts of process flow diagrams in a high-level processing canyon were prepared and used to estimate the preliminary cost of the plant to fabricate both waste forms. The estimated costs for using both options were compared for total waste management costs of SRP high-level liquid waste. Using our design, for both the ceramic and glass plant, capital and operating costs are essentially the same for both defense and commercial wastes, but total waste management costs are calculated to be significantly less for defense wastes using the ceramic option. It is concluded from this and other studies that the ceramic form may offer important advantages over glass in leach resistance, waste loading, density, and process flexibility. Preliminary economic calculations indicate that ceramics must be considered a leading candidate for the form to immobilize high-level wastes

  18. Process description and plant design for preparing ceramic high-level waste forms

    Energy Technology Data Exchange (ETDEWEB)

    Grantham, L.F.; McKisson, R.L.; Guon, J.; Flintoff, J.F.; McKenzie, D.E.

    1983-02-25

    The ceramics process flow diagram has been simplified and upgraded to utilize only two major processing steps - fluid-bed calcination and hot isostatic press consolidating. Full-scale fluid-bed calcination has been used at INEL to calcine high-level waste for 18 y; and a second-generation calciner, a fully remotely operated and maintained calciner that meets ALARA guidelines, started calcining high-level waste in 1982. Full-scale hot isostatic consolidation has been used by DOE and commercial enterprises to consolidate radioactive components and to encapsulate spent fuel elements for several years. With further development aimed at process integration and parametric optimization, the operating knowledge of full-scale demonstration of the key process steps should be rapidly adaptable to scale-up of the ceramic process to full plant size. Process flowsheets used to prepare ceramic and glass waste forms from defense and commercial high-level liquid waste are described. Preliminary layouts of process flow diagrams in a high-level processing canyon were prepared and used to estimate the preliminary cost of the plant to fabricate both waste forms. The estimated costs for using both options were compared for total waste management costs of SRP high-level liquid waste. Using our design, for both the ceramic and glass plant, capital and operating costs are essentially the same for both defense and commercial wastes, but total waste management costs are calculated to be significantly less for defense wastes using the ceramic option. It is concluded from this and other studies that the ceramic form may offer important advantages over glass in leach resistance, waste loading, density, and process flexibility. Preliminary economic calculations indicate that ceramics must be considered a leading candidate for the form to immobilize high-level wastes.

  19. Effects of heat treatment conditions on reactivity of chars in air

    Energy Technology Data Exchange (ETDEWEB)

    Ashu, J. T.; Walker, Jr., P. L.

    1977-09-01

    Reactivities of chars are maximized by keeping heat treatment temperatures as low as possible, minimizing soak time at maximum HTT and maximizing heating rates. It is feasible to use reactivity parameters as a tool for the study of thermal history of carbonaceous materials. Maximum HTT as well as the heating rate used for char preparation seem to be more important parameters in influencing char reactivity than the atmosphere used during preparation. Aging of chars in air following heat treatment at 800/sup 0/C has little or no effect on subsequent char reactivity. The most significant conclusion of this investigation is that rapid heating results in significant increase in char reactivity to air. Surface areas of rapidly heated samples are significantly higher than those prepared at the same temperature using slower heating rates.

  20. Optimization of Process Parameters of Stamping Forming of the Automotive Lower Floor Board

    Directory of Open Access Journals (Sweden)

    Guoying Ma

    2014-01-01

    Full Text Available There are many process parameters which have great effect on the forming quality of parts during automobile panel stamping forming process. This paper took automotive lower floor board as the research object; the forming process was analyzed by finite element simulation using Dynaform. The influences of four main process parameters including BHF (blank holder force, die corner radius, friction coefficient, and die clearance on the maximum thinning rate and the maximum thickening rate were researched based on orthogonal experiment. The results show that the influences of each value of various factors on the target are not identical. On this basis, the optimization of the four parameters was carried out, and the high quality product was obtained and the maximum thinning rate and maximum thickening rate were effectively controlled. The results also show that the simulation analysis provides the basis for the optimization of the forming process parameters, and it can greatly shorten the die manufacturing cycles, reduce the production costs, and improve the production efficiency.

  1. Biomedical Titanium alloy prostheses manufacturing by means of Superplastic and Incremental Forming processes

    Directory of Open Access Journals (Sweden)

    PiccininniAntonio

    2016-01-01

    Full Text Available The present work collects some results of the three-years Research Program “BioForming“, funded by the Italian Ministry of Education (MIUR and aimed to investigate the possibility of using flexible sheet forming processes, i.e. Super Plastic Forming (SPF and Single Point Incremental Forming (SPIF, for the manufacturing of patient-oriented titanium prostheses. The prosthetic implants used as case studies were from the skull; in particular, two different Ti alloys and geometries were considered: one to be produced in Ti-Gr23 by SPF and one to be produced in Ti-Gr2 by SPIF. Numerical simulations implementing material behaviours evaluated by characterization tests were conducted in order to design both the manufacturing processes. Subsequently, experimental tests were carried out implementing numerical results in terms of: (i gas pressure profile able to determine a constant (and optimal strain rate during the SPF process; (ii tool path able to avoid rupture during the SPIF process. Post forming characteristics of the prostheses in terms of thickness distributions were measured and compared to data from simulations for validation purposes. A good correlation between numerical and experimental thickness distributions has been obtained; in addition, the possibility of successfully adopting both the SPF and the SPIF processes for the manufacturing of prostheses has been demonstrated.

  2. Electron paramagnetic resonance and dynamic nuclear polarization of char suspensions: surface science and oximetry

    DEFF Research Database (Denmark)

    Clarkson, R B; Odintsov, B M; Ceroke, P J;

    1998-01-01

    Carbon chars have been synthesized in our laboratory from a variety of starting materials, by means of a highly controlled pyrolysis technique. These chars exhibit electron paramagnetic resonance (EPR) line shapes which change with the local oxygen concentration in a reproducible and stable fashion...... in conjunction with electron Zeeman pumping. Low-frequency EPR, DNP and DNP-enhanced MRI all show promise as oximetry methods when used with carbon chars....

  3. Properties of slurries made of fast pyrolysis oil and char or beech wood

    DEFF Research Database (Denmark)

    Trinh, Ngoc Trung; Jensen, Peter Arendt; Dam-Johansen, Kim;

    2014-01-01

    and ground char slurry samples with 5e20 wt% solid loading obtain a volumetric energy density of 21e23 GJ/m3. The slurry sample with 20 wt% ground char having a d80 of 118 mm was pumped successfully into a pressurized chamber (0e6 bar) while plugging appeared when the slurry samples with 15 wt% char having...... a d80 of 276 mm was pumped into the pressurized chamber....

  4. Structural evolution of biomass char and its effect on the gasification rate

    DEFF Research Database (Denmark)

    Fatehi, Hesameddin; Bai, Xue Song

    2016-01-01

    The evolution of char porous structure can affect the conversion rate of the char by affecting the intra-particle transport, especially in the zone II conversion regime. A multi-pore model based on the capillary pore theory is developed to take into account different conversion rates for pores......-pore model accommodates the detailed intra-particle transport, it is a useful basis toward developing a more predictive model for biomass char gasification....

  5. The role of quality control operations in a process of plastic forming

    OpenAIRE

    S. Topolska

    2007-01-01

    Purpose: The aim of this paper is present the role of quality control operations in such a complex manufacturing process like plastic forming. Nowadays classical manufacturing process management is replaced with total quality management philosophy.Design/methodology/approach: The presented results base on the investigations conducted in manufacturing plants of heavy industry. Next the results of researches have been compared with requirements of quality standards.Findings: Results obtained in...

  6. Automatic Process Optimization Of Sheet Metal Forming With Multi-objective

    International Nuclear Information System (INIS)

    It's crucial for process engineers to determine optimal value and combination of process parameters in the design of sheet metal forming. The multi-objective genetic algorithm (MOGA) based on Pareto approach and numerical simulation codes were integrated in this paper to fulfill the optimal formability in the sheet metal forming. Three objective functions of local formability on fracture, wrinkling and insufficient stretching were presented based on the strains state at the end of the forming process on the Forming Limit Diagram. By using Pareto-based MOGA, the optimal global formability which represents the trade-off between different local formability was decided. For the efficiency and accuracy of optimization procedure, both inverse and incremental finite element analysis were used to evaluate the value of objective functions. This method was applied to a complex engineering optimization problem: an engine hood outer panel, the optimal blank holder force and draw bead restraining forces were determined to satisfy the given objective functions for the forming of the auto body panels. The approach proposed in this paper has been shown to be a powerful tool than manual numerical simulation procedure

  7. Newly-formed emotional memories guide selective attention processes: Evidence from event-related potentials.

    Science.gov (United States)

    Schupp, Harald T; Kirmse, Ursula; Schmälzle, Ralf; Flaisch, Tobias; Renner, Britta

    2016-01-01

    Emotional cues can guide selective attention processes. However, emotional stimuli can both activate long-term memory representations reflecting general world knowledge and engage newly formed memory representations representing specific knowledge from the immediate past. Here, the self-completion feature of associative memory was utilized to assess the regulation of attention processes by newly-formed emotional memory. First, new memory representations were formed by presenting pictures depicting a person either in an erotic pose or as a portrait. Afterwards, to activate newly-built memory traces, edited pictures were presented showing only the head region of the person. ERP recordings revealed the emotional regulation of attention by newly-formed memories. Specifically, edited pictures from the erotic compared to the portrait category elicited an early posterior negativity and late positive potential, similar to the findings observed for the original pictures. A control condition showed that the effect was dependent on newly-formed memory traces. Given the large number of new memories formed each day, they presumably make an important contribution to the regulation of attention in everyday life. PMID:27321471

  8. Newly-formed emotional memories guide selective attention processes: Evidence from event-related potentials

    Science.gov (United States)

    Schupp, Harald T.; Kirmse, Ursula; Schmälzle, Ralf; Flaisch, Tobias; Renner, Britta

    2016-01-01

    Emotional cues can guide selective attention processes. However, emotional stimuli can both activate long-term memory representations reflecting general world knowledge and engage newly formed memory representations representing specific knowledge from the immediate past. Here, the self-completion feature of associative memory was utilized to assess the regulation of attention processes by newly-formed emotional memory. First, new memory representations were formed by presenting pictures depicting a person either in an erotic pose or as a portrait. Afterwards, to activate newly-built memory traces, edited pictures were presented showing only the head region of the person. ERP recordings revealed the emotional regulation of attention by newly-formed memories. Specifically, edited pictures from the erotic compared to the portrait category elicited an early posterior negativity and late positive potential, similar to the findings observed for the original pictures. A control condition showed that the effect was dependent on newly-formed memory traces. Given the large number of new memories formed each day, they presumably make an important contribution to the regulation of attention in everyday life. PMID:27321471

  9. Inhibition of steam gasification of biomass char by hydrogen and tar

    Energy Technology Data Exchange (ETDEWEB)

    Fushimi, Chihiro; Wada, Tomoko; Tsutsumi, Atsushi [Collaborative Research Center for Energy Engineering, Institute of Industrial Science, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8505 (Japan)

    2011-01-15

    The influence of hydrogen and tar on the reaction rate of woody biomass char in steam gasification was investigated by varying the concentrations in a rapid-heating thermobalance reactor. It was observed that the steam gasification of biomass char can be separated into two periods. Compared with the first period, in the second period (in which the relative mass of remaining char is smaller than 0.4) the gasification rate is increased. These effects are probably due to inherent potassium catalyst. Higher hydrogen partial pressure greatly inhibits the gasification of biomass char in the first and second periods. By calculating the first-order rate constants of char gasification in the first and second periods, we found that the hydrogen inhibition on biomass char gasification is caused by the reverse oxygen exchange reaction in the first period. In the second period, dissociative hydrogen adsorption on the char is the major inhibition reaction. The influence of levoglucosan, a major tar component derived from cellulose, was also examined. We found that not only hydrogen but also vapor-phase levoglucosan and its pyrolysates inhibited the steam gasification of woody biomass char. By mixing levoglucosan with woody biomass sample, the pyrolysis of char proceeds slightly more rapidly than with woody biomass alone, and gas evolution rates of H{sub 2} and CO{sub 2} are larger in steam gasification. (author)

  10. Production of activated char from Illinois coal for flue gas cleanup

    Science.gov (United States)

    Lizzio, A.A.; DeBarr, J.A.; Kruse, C.W.

    1997-01-01

    Activated chars were produced from Illinois coal and tested in several flue gas cleanup applications. High-activity chars that showed excellent potential for both SO2 and NOx removal were prepared from an Illinois No. 2 bituminous coal. The SO2 (120 ??C) and NOx (25 ??C) removal performance of one char compared favorably with that of a commercial activated carbon (Calgon Centaur). The NOx removal performance of the same char at 120 ??C exceeded that of the Centaur carbon by more than 1 order of magnitude. Novel char preparation methods were developed including oxidation/thermal desorption and hydrogen treatments, which increased and preserved, respectively, the active sites for SO2 and NOx adsorption. The results of combined SO2/NOx removal tests, however, suggest that SO2 and NOx compete for similar adsorption sites and SO2 seems to be more strongly adsorbed than NO. A low-activity, low-cost char was also developed for cleanup of incinerator flue gas. A three-step method involving coal preoxidation, pyrolysis, and CO2 activation was used to produce the char from Illinois coal. Five hundred pounds of the char was tested on a slipstream of flue gas from a commercial incinerator in Germany. The char was effective in removing >97% of the dioxins and furans present in the flue gas; mercury levels were below detectable limits.

  11. Effect of pyrolysis pressure and heating rate on radiata pine char structure and apparent gasification reactivity

    Energy Technology Data Exchange (ETDEWEB)

    E. Cetin; R. Gupta; B. Moghtaderi [University of Newcastle, Callaghan, NSW (Australia). Discipline of Chemical Engineering, Faculty of Engineering and Built Environment, School of Engineering

    2005-07-01

    The knowledge of biomass char gasification kinetics has considerable importance in the design of advanced biomass gasifiers, some of which operate at high pressure. The char gasification kinetics themselves are influenced by char structure. In this study, the effects of pyrolysis pressure and heating rate on the char structure were investigated using scanning electron microscopy (SEM) analysis, digital cinematography, and surface area analysis. Char samples were prepared at pressures between 1 and 20 bar, temperatures ranging from 800 to 1000{degree}C, and heating rates between 20 and 500{degree}C/s. Our results indicate that pyrolysis conditions have a notable impact on the biomass char morphology. Pyrolysis pressure, in particular, was found to influence the size and the shape of char particles while high heating rates led to plastic deformation of particles (i.e. melting) resulting in smooth surfaces and large cavities. The global gasification reactivities of char samples were also determined using thermogravimetric analysis (TGA) technique. Char reactivities were found to increase with increasing pyrolysis heating rates and decreasing pyrolysis pressure. 22 refs., 8 figs., 2 tabs.

  12. The image simulation arithmetic of the degradating process of porous biologic ceramic in life-form

    Institute of Scientific and Technical Information of China (English)

    CHEN Zuo-bing; HUANG Jian-zhong; YAN Yu-hua; LI Shi-pu

    2001-01-01

    @@ It is a complex and difficult task to simulate the degradating process of porous biologic ceramic in life-form by computer. Because the evolvement of crystal' s structure deals with not only the mechanism of many factors, such as crystallography tropism, the reciprocity of wafer, interfacial movement, but also topology geometry mechanism of dimensional padding.

  13. Mechanical and Metallurgical Evolution of Stainless Steel 321 in a Multi-step Forming Process

    Science.gov (United States)

    Anderson, M.; Bridier, F.; Gholipour, J.; Jahazi, M.; Wanjara, P.; Bocher, P.; Savoie, J.

    2016-04-01

    This paper examines the metallurgical evolution of AISI Stainless Steel 321 (SS 321) during multi-step forming, a process that involves cycles of deformation with intermediate heat treatment steps. The multi-step forming process was simulated by implementing interrupted uniaxial tensile testing experiments. Evolution of the mechanical properties as well as the microstructural features, such as twins and textures of the austenite and martensite phases, was studied as a function of the multi-step forming process. The characteristics of the Strain-Induced Martensite (SIM) were also documented for each deformation step and intermediate stress relief heat treatment. The results indicated that the intermediate heat treatments considerably increased the formability of SS 321. Texture analysis showed that the effect of the intermediate heat treatment on the austenite was minor and led to partial recrystallization, while deformation was observed to reinforce the crystallographic texture of austenite. For the SIM, an Olson-Cohen equation type was identified to analytically predict its formation during the multi-step forming process. The generated SIM was textured and weakened with increasing deformation.

  14. The impact of recreational MDMA 'ecstasy' use on global form processing.

    Science.gov (United States)

    White, Claire; Edwards, Mark; Brown, John; Bell, Jason

    2014-11-01

    The ability to integrate local orientation information into a global form percept was investigated in long-term ecstasy users. Evidence suggests that ecstasy disrupts the serotonin system, with the visual areas of the brain being particularly susceptible. Previous research has found altered orientation processing in the primary visual area (V1) of users, thought to be due to disrupted serotonin-mediated lateral inhibition. The current study aimed to investigate whether orientation deficits extend to higher visual areas involved in global form processing. Forty-five participants completed a psychophysical (Glass pattern) study allowing an investigation into the mechanisms underlying global form processing and sensitivity to changes in the offset of the stimuli (jitter). A subgroup of polydrug-ecstasy users (n=6) with high ecstasy use had significantly higher thresholds for the detection of Glass patterns than controls (n=21, p=0.039) after Bonferroni correction. There was also a significant interaction between jitter level and drug-group, with polydrug-ecstasy users showing reduced sensitivity to alterations in jitter level (p=0.003). These results extend previous research, suggesting disrupted global form processing and reduced sensitivity to orientation jitter with ecstasy use. Further research is needed to investigate this finding in a larger sample of heavy ecstasy users and to differentiate the effects of other drugs.

  15. The Model of Forming Communicative Competence of Students in the Process of Teaching the English Language

    Science.gov (United States)

    Fahrutdinova, Rezida A.; Fahrutdinov, Rifat R.; Yusupov, Rinat N.

    2016-01-01

    The relevance of the topic is specified by the necessity of forming the communicative competence of students in the process of teaching of the English language in the institute of higher education. This article is intended to define interactive methods of teaching foreign language, which are based on interactive conception of interaction between…

  16. Implementation of Microstructural Material Phenomena in Macro Scale Simulations of Forming Processes

    NARCIS (Netherlands)

    Huetink, J.

    2004-01-01

    The paper deals with problems related to full/macro scale simulations of industrial forming processes. Large-scale numerical simulations and virtual modeling are replacing prototypes in order to reduce costs and time. This requires accurate and reliable predictions. To satisfy these requirements, so

  17. A national effort to identify fry processing clones with low acrylamide-forming potential

    Science.gov (United States)

    Acrylamide is a suspected human carcinogen. Processed potato products, such as chips and fries, contribute to dietary intake of acrylamide. One of the most promising approaches to reducing acrylamide consumption is to develop and commercialize new potato varieties with low acrylamide-forming potenti...

  18. Modeling of Thermo-Electro-Mechanical Manufacturing Processes Applications in Metal Forming and Resistance Welding

    CERN Document Server

    Nielsen, C V; Alves, L M; Bay, N; Martins, P A F

    2013-01-01

    Modeling of Thermo-Electro-Mechanical Manufacturing Processes with Applications in Metal Forming and Resistance Welding provides readers with a basic understanding of the fundamental ingredients in plasticity, heat transfer and electricity that are necessary to develop and proper utilize computer programs based on the finite element flow formulation.   Computer implementation of a wide range of theoretical and numerical subjects related to mesh generation, contact algorithms, elasticity, anisotropic constitutive equations, solution procedures and parallelization of equation solvers is comprehensively described.   Illustrated and enriched with selected examples obtained from industrial applications, Modeling of Thermo-Electro-Mechanical Manufacturing Processes with Applications in Metal Forming and Resistance Welding works to diminish the gap between the developers of finite element computer programs and the professional engineers with expertise in industrial joining technologies by metal forming and resista...

  19. Controlled Nucleation Method:A New Process for Semisolid Metal Forming

    Institute of Scientific and Technical Information of China (English)

    王浩

    2005-01-01

    Semisolid metal forming requires special feedstock material with a fine-grained and globular structure to achieve thixotropic properties. A number of methods have been developed to produce such feedstock materials. Controlled Nucleation Method (CNM) is a new and simple, cost effective method that has been developed by the University of Queensland. The CNM process does not use the conventional stirring process, instead, it uses solidification conditions to control nucleation, nuclei survival and grain growth, thereby produce fine and globular structures suitable for semisolid forming. No specialised equipment is required. The method can produce both semisolid slurry for rheocasting and semisolid billet for thixocasting. It can be applied to a wide range of alloys and can easily be incorporated into existing metal forming installation. Semisolid slurries/billets of hypoeutectic and hypereutectic aluminium-silicon casting alloys, aluminium wrought alloys and a magnesium alloys have been successfully produced.

  20. Maturity determination and information visualization of new forming processes considering uncertain indicator values

    Science.gov (United States)

    Weckenmann, A.; Akkasoglu, G.

    2012-04-01

    Operative or strategic decision-making during the development of novel objects is complicated and mostly based on fuzzy assumptions or uncertain information. Consideration of information uncertainty would enhance the reliability of any evaluation of the current development status of new objects. Decisions could be made with a higher safety. The development status equates to the maturity and is to be assessed by previously elicited indicators in relation to phase-dependent requirements. Within this paper, a reference-model based maturity method considering uncertain indicators is introduced for enabling the determination and assurance of the development status in a quantitative and systematic way. The method is applied within the development of a novel metal forming process namely the Sheet-Bulk Metal Forming, which aims to unite the advantages of sheet metal and bulk metal forming. Additionally techniques for visualizing the determined maturity value are proposed to support subsequent decision processes in the context of maturity assurance or improvement.

  1. Endoscopic fringe projection for in-situ inspection of a sheet-bulk metal forming process

    Science.gov (United States)

    Matthias, Steffen; Kästner, Markus; Reithmeier, Eduard

    2015-05-01

    Sheet-bulk metal forming is a new production process capable of performing deep-drawing and massive forming steps in a single operation. However, due to the high forming forces of the forming process, continuous process control is required in order to detect wear on the forming tool before production quality is impacted. To be able to measure the geometry of the forming tool in the limited space of forming presses, a new inspection system is being developed within the SFB/TR 73 collaborative research center. In addition to the limited space, the process restricts the amount of time available for inspection. Existing areal optical measurement systems suffer from shadowing when measuring the tool's inner elements, as they cannot be placed in the limited space next to the tool, while tactile measurement systems cannot meet the time restrictions for measuring the areal geometries. The new inspection system uses the fringe projection optical measurement principle to capture areal geometry data from relevant parts of the forming tool in short time. Highresolution image fibers are used to connect the system's compact sensor head to a base unit containing both camera and projector of the fringe projection system, which can be positioned outside of the moving parts of the press. To enable short measurement times, a high intensity laser source is used in the projector in combination with a digital micro-mirror device. Gradient index lenses are featured in the sensor head to allow for a very compact design that can be used in the narrow space above the forming tool inside the press. The sensor head is attached to an extended arm, which also guides the image fibers to the base unit. A rotation stage offers the possibility to capture measurements of different functional elements on the circular forming tool by changing the orientation of the sensor head next to the forming tool. During operation of the press, the arm can be travelled out of the moving parts of the forming press

  2. KINETICS AND MECHANISMS OF NOx - CHAR REDUCTION

    Energy Technology Data Exchange (ETDEWEB)

    Suuberg, E.M.

    1998-06-19

    This study was undertaken in order to improve understanding of several aspects of the NO-carbon reaction. This reaction is of practical importance in combustion systems, but its close examination also provides some fundamental insight into oxidizing gas-carbon reactions. As part of this study, a comprehensive literature review of earlier work on this reaction has been published (Aarna and Suuberg, Fuel, 1997, 76, 475-491). It has been thought for some time that the kinetics of the NO-carbon reaction are unusual, in that they often show a two-regime Arrhenius behavior. It has, however, turned out during this work that NO is not alone in this regard. In this laboratory, we also uncovered evidence of two kinetic regime behavior in CO{sub 2} gasification. In another laboratory, a former colleague has identified the same behavior in N{sub 2}O. The low temperature reaction regime always shows an activation energy which is lower than that in the high temperature regime, leaving little doubt that a shift in mechanism, as opposed to transport limitations, dictates the behavior. The activation energy of the low temperature regime of these reactions is typically less than 100 kJ/mol, and the activation energy of the high temperature regime is generally considerably in excess of this value. In this study, we have resolved some apparent inconsistencies in the explanation of the low temperature regime, whose rate has generally been ascribed to desorption-controlled processes. Part of the problem in characterization of the different temperature regimes is that they overlap to a high degree. It is difficult to probe the low temperature regime experimentally, because of slow relaxation of the surface oxides in that regime. Using careful experimental techniques, we were able to demonstrate that the low temperature regime is indeed characterized by zero order in NO, as it must be. A separate study is being carried out to model the behavior in this regime in NO and in other gases, and

  3. Forming of tubes and bars of alumina/LY12 composites by liquid extrusion process

    Institute of Scientific and Technical Information of China (English)

    齐乐华; 李贺军; 崔培玲; 史忠科

    2003-01-01

    Tube and bar products of aluminum alloy composites reinforced by alumina short-fiber were formed in a single process with liquid extrusion technology. The microstructure verifies that the reinforcing effect is obvious in the deformation direction since fibers are distributed along this direction, which is resulted from the flow and crystallization under pressure of liquid metal and large plastic deformation of solidified metal in the process. The interface between fiber and matrix belongs to mechanical bonding. The fractograph demonstrates ductile mode. Liquid extrusion process opens up a new way for fabricating tube, bar and shaped products.

  4. The Topographic Design of River Channels for Form-Process Linkages

    Science.gov (United States)

    Brown, Rocko A.; Pasternack, Gregory B.; Lin, Tin

    2016-04-01

    Scientists and engineers design river topography for a wide variety of uses, such as experimentation, site remediation, dam mitigation, flood management, and river restoration. A recent advancement has been the notion of topographical design to yield specific fluvial mechanisms in conjunction with natural or environmental flow releases. For example, the flow convergence routing mechanism, whereby shear stress and spatially convergent flow migrate or jump from the topographic high (riffle) to the low point (pool) from low to high discharge, is thought to be a key process able to maintain undular relief in gravel bedded rivers. This paper develops an approach to creating riffle-pool topography with a form-process linkage to the flow convergence routing mechanism using an adjustable, quasi equilibrium synthetic channel model. The link from form to process is made through conceptualizing form-process relationships for riffle-pool couplets into geomorphic covariance structures (GCSs) that are then quantitatively embedded in a synthetic channel model. Herein, GCSs were used to parameterize a geometric model to create five straight, synthetic river channels with varying combinations of bed and width undulations. Shear stress and flow direction predictions from 2D hydrodynamic modeling were used to determine if scenarios recreated aspects of the flow convergence routing mechanism. Results show that the creation of riffle-pool couplets that experience flow convergence in straight channels requires GCSs with covarying bed and width undulations in their topography as supported in the literature. This shows that GCSs are a useful way to translate conceptualizations of form-process linkages into quantitative models of channel form.

  5. New isotopic evidence bearing on bonanza (Au-Ag) epithermal ore-forming processes

    Science.gov (United States)

    Saunders, James A.; Mathur, Ryan; Kamenov, George D.; Shimizu, Toru; Brueseke, Matthew E.

    2016-01-01

    New Cu, S, and Pb isotope data provide evidence for a magmatic source of metal(loid)s and sulfur in epithermal Au-Ag deposits even though their ore-forming solutions are composed primarily of heated meteoric (ground) waters. The apparent isotopic discrepancy between ore metals and ore-forming solutions, and even between the ore and associated gangue minerals, indicates two different sources of epithermal ore-forming constituents: (1) a shallow geothermal system that not only provides the bulk of water for the ore-forming solutions but also major chemical constituents leached from host rocks (silica, aluminum, potassium, sodium, calcium) to make gangue minerals and (2) metals and metalloids (As, Te, Sb, etc.) and sulfur (±Se) derived from deeper magma bodies. Isotopic data are consistent with either vapor-phase transport of metal(loids) and sulfur and their subsequent absorption by shallow geothermal waters or formation of metallic (Au, Ag, Cu phases) nanoparticles at depth from magmatic fluids prior to encountering the geothermal system. The latter is most consistent with ore textures that indicate physical transport and aggregation of nanoparticles were significant ore-forming processes. The recognition that epithermal Au-Ag ores form in tectonic settings that produce magmas capable of releasing metal-rich fluids necessary to form these deposits can refine exploration strategies that previously often have focused on locating fossil geothermal systems.

  6. Reliability Estimation of the Pultrusion Process Using the First-Order Reliability Method (FORM)

    DEFF Research Database (Denmark)

    Baran, Ismet; Tutum, Cem Celal; Hattel, Jesper Henri

    2013-01-01

    In the present study the reliability estimation of the pultrusion process of a flat plate is analyzed by using the first order reliability method (FORM). The implementation of the numerical process model is validated by comparing the deterministic temperature and cure degree profiles...... with corresponding analyses in the literature. The centerline degree of cure at the exit (CDOCE) being less than a critical value and the maximum composite temperature (Tmax) during the process being greater than a critical temperature are selected as the limit state functions (LSFs) for the FORM. The cumulative...... in the probability of Tmax being greater than the resin degradation temperature. A similar trend is also seen for the probability of the CDOCE being less than 0.8....

  7. Energy (mass) transfer processes in low-temperature plasma as applied to forming ordered structures

    Science.gov (United States)

    Abramenko, T. N.; Laktyushina, T. V.; Laktyushin, A. N.

    2000-03-01

    The methods of irreversible thermodynamics are adopted to analyze the energy (mass) transfer in gases (their mixtures) over a wide temperature range up to 20000 K. An energy transfer process is considered as a path in the state space, and a concept of non-Euclidean state space is postulated. Experimental data on the gas thermal conductivity over a wide temperature range is generalized by the methods of thermodynamic similarity theory. Thermal conductivities of CH4-O2 and CH4-H2O mixtures are calculated for technological applications. The process of forming a space-time structure is analyzed by using the experimental data on the gas thermal conductivity over a wide temperature range. An attempt is made to interpret the mechanism of the thermal diffusion in gases due to the forming of ordered structures. A contribution of the diffusional thermoeffect to the energy transfer processes in a three-component nitrogen plasma is calculated.

  8. Is this charred material from a VHS video cassette?

    Science.gov (United States)

    Fruchtenicht, Tara; Blackledge, Robert D.; Williams, Teresa R.

    2010-06-01

    At his residence, a victim in a double homicide had installed a home-built video surveillance system. The suspects either knew of or discovered this system and removed it. In a backyard at a location associated with the suspects was a barrel used for burning trash. Could charred debris recovered from a metal bowl found among the contents of the barrel be the remains of a VHS video cassette? A positive answer to the question was obtained through a combination of optical microscopy, Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and Energy Dispersive Spectroscopy (EDS).

  9. One kind of technology on producing char without pollution

    Energy Technology Data Exchange (ETDEWEB)

    Yin Chengxu [Kunming Inst. of Coal Science (China). Dept. of Coal Chemical Engineering

    1997-12-31

    This paper introduces one kind of technology on continually producing char without pollution. The capacity of each furnace is treating 5000 tons of brown coal annually. The production has been kept running for one year. Its products are high quality reducing agent for the iron alloy, calcium carbide and yellow phosphorus etc. This technology has the advantages of less investment, easy to manage, low energy consumption and environmental-friendly. The abundant heat could be utilized to produce steam for thermal supply and power generation. (orig.)

  10. Simulation study for atomic size and alloying effects during forming processes of amorphous alloys

    Institute of Scientific and Technical Information of China (English)

    ZHENG Caixing; LIU Rangsu; PENG Ping; ZHOU Qunyi

    2004-01-01

    A molecular dynamics (MD) simulation study has been performed for the solidification processes of two binary liquid alloys Ag6Cu4 and CuNi by adopting the quantum Sutton-Chen many-body potentials. By analyzing bond-types, it is demonstrated that at the cooling rate of 2×1012K/s, the CuNi forms fcc crystal structures, while the Ag6Cu4 forms amorphous structures. The original reason is that the atomic radius ratio (1.13) of the CuAg is bigger than that (1.025) of the CuNi. This shows that the atomic size difference is indeed the main factor for forming amorphous alloys. Moreover, for Ag60Cu40,corresponding to the deep eutectic point in the phase diagram, it forms amorphous structure easily. This confirms that as to the forming tendency and stability of amorphous alloys, the alloying effect plays a key role. In addition, having analyzed the transformation of microstructures by using the bond-type index and cluster-type index methods, not only the key role of the icosahedral configuration to the formation and stability of amorphous alloys can be explained, but also the solidification processes of liquid metals and the characteristics of amorphous structures can be further understood.

  11. Reliability Estimation of the Pultrusion Process Using the First-Order Reliability Method (FORM)

    Science.gov (United States)

    Baran, Ismet; Tutum, Cem C.; Hattel, Jesper H.

    2013-08-01

    In the present study the reliability estimation of the pultrusion process of a flat plate is analyzed by using the first order reliability method (FORM). The implementation of the numerical process model is validated by comparing the deterministic temperature and cure degree profiles with corresponding analyses in the literature. The centerline degree of cure at the exit (CDOCE) being less than a critical value and the maximum composite temperature ( T max) during the process being greater than a critical temperature are selected as the limit state functions (LSFs) for the FORM. The cumulative distribution functions of the CDOCE and T max as well as the correlation coefficients are obtained by using the FORM and the results are compared with corresponding Monte-Carlo simulations (MCS). According to the results obtained from the FORM, an increase in the pulling speed yields an increase in the probability of T max being greater than the resin degradation temperature. A similar trend is also seen for the probability of the CDOCE being less than 0.8.

  12. Development of Aluminum-Lithium 2195 Gores by the Stretch Forming Process

    Science.gov (United States)

    Volz, M. P.; Chen, P. S.; Gorti, S.; Salvail, P.

    2014-01-01

    Aluminum-Lithium alloy 2195 exhibits higher mechanical properties and lower density than aluminum alloy 2219, which is the current baseline material for Space Launch System (SLS) cryogenic tank components. Replacement of Al 2219 with Al-Li 2195 would result in substantial weight savings, as was the case when this replacement was made on the shuttle external tank. A key component of cryogenic tanks are the gores, which are welded together to make the rounded ends of the tanks. The required thicknesses of these gores depend on the specific SLS configuration and may exceed the current experience base in the manufacture of such gores by the stretch forming process. Here we describe the steps taken to enhance the formability of Al-Li 2195 by optimizing the heat treatment and stretch forming processes for gore thicknesses up to 0.75", which envelopes the maximum expected gore thicknesses for SLS tanks. An annealing treatment, developed at Marshall Space Flight Center, increased the forming range and strain hardening exponent of Al-Li 2195 plates. Using this annealing treatment, one 0.525" thick and two 0.75" thick gores were manufactured by the stretch forming process. The annealing treatment enabled the stretch forming of the largest ever cross sectional area (thickness x width) of an Al-Li 2195 plate achieved by the manufacturer. Mechanical testing of the gores showed greater than expected ultimate tensile strength, yield strength, modulus, and elongation values. The gores also exhibited acceptable fracture toughness at room and LN2 temperatures. All of the measured data indicate that the stretch formed gores have sufficient material properties to be used in flight domes.

  13. An in-process form error measurement system for precision machining

    International Nuclear Information System (INIS)

    In-process form error measurement for precision machining is studied. Due to two key problems, opaque barrier and vibration, the study of in-process form error optical measurement for precision machining has been a hard topic and so far very few existing research works can be found. In this project, an in-process form error measurement device is proposed to deal with the two key problems. Based on our existing studies, a prototype system has been developed. It is the first one of the kind that overcomes the two key problems. The prototype is based on a single laser sensor design of 50 nm resolution together with two techniques, a damping technique and a moving average technique, proposed for use with the device. The proposed damping technique is able to improve vibration attenuation by up to 21 times compared to the case of natural attenuation. The proposed moving average technique is able to reduce errors by seven to ten times without distortion to the form profile results. The two proposed techniques are simple but they are especially useful for the proposed device. For a workpiece sample, the measurement result under coolant condition is only 2.5% larger compared with the one under no coolant condition. For a certified Wyko test sample, the overall system measurement error can be as low as 0.3 µm. The measurement repeatability error can be as low as 2.2%. The experimental results give confidence in using the proposed in-process form error measurement device. For better results, further improvement in design and tests are necessary

  14. Production and characterization of Lemna minor bio-char and its catalytic application for biogas reforming

    International Nuclear Information System (INIS)

    Pyrolysis of fast-growing aquatic biomass - Lemna minor (commonly known as duckweed) with the emphasis on production, characterization and catalytic application of bio-char is reported in this paper. The yield of bio-char was determined as a function of L. minor pyrolysis temperature and sweep gas flow rate. It was found that the pore development during L. minor pyrolysis was not significant and the changes in the reaction conditions (temperature and sweep gas flow rate) did not alter markedly the textural characteristics and BET surface area of the bio-char produced. Thermogravimetric/differential thermogravimetric (TG/DTG) analyses of L. minor and different bio-char samples in inert (helium) and oxidative (air) media showed substantial differences in their TG/DTG patterns. A comparison of scanning electron micrographs (SEM) of L. minor, bio-char and ash indicated that the basic structural features of L. minor remained intact and were not affected by thermolysis. The inorganic ash content of L. minor derived bio-char is significantly higher than that of typical terrestrial (plant) biomass. The energy dispersive spectroscopic (EDS) analysis of L. minor ash showed that it mostly consisted of silica, and small quantities of Na, K and Ca compounds. The treatment of bio-char with CO2 at 800 °C increased its BET surface area. It was found that CO2-treated bio-char exhibited appreciable initial catalytic activity in biogas reforming. -- Highlights: New data on characterization of bio-chars derived from Lemna minor are presented. ► Effect of pyrolysis operational parameters on bio-char properties is determined. ► Basic skeletal structure of Lemna minor leaflets does not change during pyrolysis. ► Bio-chars show an appreciable initial catalytic activity for biogas reforming.

  15. Preparation of porous bio-char and activated carbon from rice husk by leaching ash and chemical activation.

    Science.gov (United States)

    Ahiduzzaman, Md; Sadrul Islam, A K M

    2016-01-01

    Preparation porous bio-char and activated carbon from rice husk char study has been conducted in this study. Rice husk char contains high amount silica that retards the porousness of bio-char. Porousness of rice husk char could be enhanced by removing the silica from char and applying heat at high temperature. Furthermore, the char is activated by using chemical activation under high temperature. In this study no inert media is used. The study is conducted at low oxygen environment by applying biomass for consuming oxygen inside reactor and double crucible method (one crucible inside another) is applied to prevent intrusion of oxygen into the char. The study results shows that porous carbon is prepared successfully without using any inert media. The adsorption capacity of material increased due to removal of silica and due to the activation with zinc chloride compared to using raw rice husk char. The surface area of porous carbon and activated carbon are found to be 28, 331 and 645 m(2) g(-1) for raw rice husk char, silica removed rice husk char and zinc chloride activated rice husk char, respectively. It is concluded from this study that porous bio-char and activated carbon could be prepared in normal environmental conditions instead of inert media. This study shows a method and possibility of activated carbon from agro-waste, and it could be scaled up for commercial production. PMID:27536531

  16. Preparation of porous bio-char and activated carbon from rice husk by leaching ash and chemical activation.

    Science.gov (United States)

    Ahiduzzaman, Md; Sadrul Islam, A K M

    2016-01-01

    Preparation porous bio-char and activated carbon from rice husk char study has been conducted in this study. Rice husk char contains high amount silica that retards the porousness of bio-char. Porousness of rice husk char could be enhanced by removing the silica from char and applying heat at high temperature. Furthermore, the char is activated by using chemical activation under high temperature. In this study no inert media is used. The study is conducted at low oxygen environment by applying biomass for consuming oxygen inside reactor and double crucible method (one crucible inside another) is applied to prevent intrusion of oxygen into the char. The study results shows that porous carbon is prepared successfully without using any inert media. The adsorption capacity of material increased due to removal of silica and due to the activation with zinc chloride compared to using raw rice husk char. The surface area of porous carbon and activated carbon are found to be 28, 331 and 645 m(2) g(-1) for raw rice husk char, silica removed rice husk char and zinc chloride activated rice husk char, respectively. It is concluded from this study that porous bio-char and activated carbon could be prepared in normal environmental conditions instead of inert media. This study shows a method and possibility of activated carbon from agro-waste, and it could be scaled up for commercial production.

  17. Two-pulse NMR techniques for studying proton-unpaired electron interactions in coals and chars

    Science.gov (United States)

    Barton, W. A.; Lynch, L. J.

    The time-domain NMR signals stimulated in solids by two-pulse sequences of the form 90°- τ- βφ, where β is the angle of rotation and φ the relative phase of the second pulse which is separated from the initial 90° pulse by a time τ, can be influenced by the presence of a second spin species and therefore, in principle, can yield information on the separate contributions, M2II and M2IS, of like- and unlike-spin interactions to the Van Vleck second moment M2I of the resonant spins. The validity of the standard operator formalism for predicting the transverse magnetization signals thus produced in homogeneous solids by the 90°- τ-90 φ° and 90°- τ-180 φ° ( φ = 0° and 90°) sequences is discussed and the effects of pulse duration are briefly outlined. The time-series expansions yielded by the operator formalism for these signals are reviewed with emphasis on the effects of unlike-spin interactions, and a useful difference signal is discussed. The potential for application of these two-pulse techniques to protons in heterogeneous solids such as coals, in which unpaired electrons constitute the second spin species, is considered and experimentally assessed. Semiquantitative estimates of M2IS are made for protons in diphenyl picryl hydrazyl (DPPH) and several coals and chars at room temperature from measurements of the amplitude of the 90°- τ-90° 0 ° transient signal at small τ and of the initial rate of attenuation of the 90°- τ-90 90°° solid echo with increasing τ. It is found that (i) organic radicals and paramagnetic ions produce relatively small M2IS values, a result which limits the usefulness of this approach to studying unpaired electron properties of coals and chars; (ii) the M2II values deduced from these results and calculations of M2I follow expected trends; and (iii) only specimens containing small particles of magnetically ordered material give rise to rapidly decaying time-domain signals and a well-defined 90°- τ-180 90°° spin

  18. MECHANICS ANALYSIS ON PRECISE FORMING PROCESS OF EXTERNAL SPLINE COLD ROLLING

    Institute of Scientific and Technical Information of China (English)

    ZHANG Dawei; LI Yongtang; FU Jianhua; ZHENG Quangang

    2007-01-01

    According to the suitable assumption, the deformation process of external spline cold rolling is analyzed. By the graphing method, the slip-line field of plastically deforming area in process of external spline cold rolling is set up. Different friction-conditions are used in different contact areas in order to realistically reflect the actual situation. The unit average pressure on contact surface of the rolling process is solved according to the stress filed theory of slip-line. And the formulae of the rolling-force and rolling-moment are established. The theoretical result is well consistent with the finite element analysis. A theoretical basis is provided for the precise forming process of spline cold rolling and the production of external splined shafts.

  19. Free form fabrication of metallic components using the Directed Light Fabrication process

    Energy Technology Data Exchange (ETDEWEB)

    Lewis, G.K.; Milewski, J.O.; Nemec, R.B.; Thoma, D.J.

    1998-03-01

    The Directed Light Fabrication (DLF) process uses a laser beam and metal powder, fed into the laser focal zone, to produce free standing metal components that are fully dense and have structural properties equivalent to conventional metal forming processes. The motion of the laser focal zone is precisely controlled by a motion path produced from a 3 dimensional solid model of a desired component. The motion path commands move the focal zone of the laser such that all solid areas of the part are deposited and the part can be built (deposited) in its entirety to near net shape, typically within {+-} 0.13 mm. The process is applicable to any metal or intermetallic. Full density and mechanical properties equivalent to conventionally processed material are achieved.

  20. Rheology as a tool for evaluation of melt processability of innovative dosage forms

    DEFF Research Database (Denmark)

    Aho, Johanna Maaria; Boetker, Johan P; Baldursdottir, Stefania;

    2015-01-01

    -polymer mixtures is highly dependent on the rheological properties of these systems, and rheological measurements should be considered as a more central part of the material characterization tool box when selecting suitable candidates for melt processing by, e.g., HME or 3D printing. The polymer processing......Future manufacturing of pharmaceuticals will involve innovative use of polymeric excipients. Hot melt extrusion (HME) is an already established manufacturing technique and several products based on HME are on the market. Additionally, processing based on, e.g., HME or three dimensional (3D......) printing, will have an increasingly important role when designing products for flexible dosing, since dosage forms based on compacting of a given powder mixture do not enable manufacturing of optimal pharmaceutical products for personalized treatments. The melt processability of polymers and API...

  1. Simulation of coal char gasification using O2/CO2

    Institute of Scientific and Technical Information of China (English)

    Haibin Li; Yu Yu; Minfang Han; Ze Lei

    2014-01-01

    The authors proposed an integrated gasification fuel cell zero-emission system. The coal char gasification is discussed using high temperature and concentration of CO2 produced by solid oxide fuel cells and oxy-fuel combustion. The gasification is simulated by Aspen plus based on Gibbs free energy minimization method. Gasification model of pulverized coal char is computed and analyzed. Effects of gas flow rate, pressure, preheating temperature, heat losses on syngas composition, reaction temperature, lower heating value and carbon conversion are studied. Results and parameters are determined as following. The optimum O2 flow rate is 20 kg/h. The reaction temperature decreases from 1645 to 1329 ?C when the CO2 flow rate increases from 0 to 5 kg/h, the CO2 flow rate should be operated reasonably; lower heating value reduces and reaction temperature increases as the pressure increases;compared to the CO2 preheating, O2 preheating has greater influence on reaction temperature and lower heating value.

  2. Reaction Kinetic Equation for Char Combustion of Underground Coal Gasification

    Institute of Scientific and Technical Information of China (English)

    YU Hong-guan; YANG Lan-he; FENG Wei-min; LIU Shu-qin; SONG Zhen-qi

    2006-01-01

    Based on the quasi-steady-state approximation, the dynamic equation of char combustion in the oxidation zone of underground coal gasification (UCG) was derived. The parameters of the dynamic equation were determined at 900℃ using a thermo-gravimetric (TG) analyzer connected to a flue gas analyzer and this equation. The equation was simplified for specific coals, including high ash content, low ash content, and low ash fusibility ones. The results show that 1) the apparent reaction rate constant increases with an increase in volatile matter value as dry ash-free basis, 2) the effective coefficient of diffusion decreases with an increase in ash as dry basis, and 3) the mass transfer coefficient is independent of coal quality on the whole. The apparent reaction rate constant, mass-transfer coefficient and effective coefficient of diffusion of six char samples range from 7.51×104 m/s to 8.98×104 m/s, 3.05×106 m/s to 3.23×106 m/s and 5.36×106 m2/s to 8.23×106 m2/s at 900℃, respectively.

  3. Process of forming compounds using reverse micelle or reverse microemulsion systems

    Science.gov (United States)

    Linehan, John C.; Fulton, John L.; Bean, Roger M.

    1998-01-01

    The present invention is directed to a process for producing a nanometer-sized metal compound. The process comprises forming a reverse micelle or reverse microemulsion system comprising a polar fluid in a non-polar or low-polarity fluid. A first reactant comprising a multi-component, water-soluble metal compound is introduced into the polar fluid in a non-polar or low-polarity fluid. This first reactant can be introduced into the reverse micelle or reverse microemulsion system during formation thereof or subsequent to the formation of the reverse micelle or microemulsion system. The water-soluble metal compound is then reacted in the reverse micelle or reverse microemulsion system to form the nanometer-sized metal compound. The nanometer-sized metal compound is then precipitated from the reverse micelle or reverse microemulsion system.

  4. SCALE UP OF CERAMIC WASTE FORMS FOR THE EBR-II SPENT FUEL TREATMENT PROCESS

    Energy Technology Data Exchange (ETDEWEB)

    Matthew C. Morrison; Kenneth J. Bateman; Michael F. Simpson

    2010-11-01

    ABSTRACT SCALE UP OF CERAMIC WASTE FORMS FOR THE EBR-II SPENT FUEL TREATMENT PROCESS Matthew C. Morrison, Kenneth J. Bateman, Michael F. Simpson Idaho National Laboratory, P.O. Box 1625, Idaho Falls, ID 83415 The ceramic waste process is the intended method for disposing of waste salt electrolyte, which contains fission products from the fuel-processing electrorefiners (ER) at the INL. When mixed and processed with other materials, the waste salt can be stored in a durable ceramic waste form (CWF). The development of the CWF has recently progressed from small-scale testing and characterization to full-scale implementation and experimentation using surrogate materials in lieu of the ER electrolyte. Two full-scale (378 kg and 383 kg) CWF test runs have been successfully completed with final densities of 2.2 g/cm3 and 2.1 g/cm3, respectively. The purpose of the first CWF was to establish material preparation parameters. The emphasis of the second pre-qualification test run was to evaluate a preliminary multi-section CWF container design. Other considerations were to finalize material preparation parameters, measure the material height as it consolidates in the furnace, and identify when cracking occurs during the CWF cooldown process.

  5. The Role of Sexual Disorder in FormingDivorce Process: a Grounded Theory Study

    OpenAIRE

    H enayat; SU Panjehband

    2016-01-01

    Background & Aim: consequences resulting in the increase of the divorce rate in the Iranian society, which surrounded all individuals, families and society, has prepared the background of the present study. The main purpose of the present study was demonstrating a paradigm model of the role of sexual disorder in forming the divorce process among men in Iran. Method: The present study was conducted by applying a qualitative method using the grounded theory approach in Gachs...

  6. An expert system for ensuring the reliability of the technological process of cold sheet metal forming

    Science.gov (United States)

    Kashapova, L. R.; Pankratov, D. L.; Utyaganov, P. P.

    2016-06-01

    In order to exclude periodic defects in the parts manufacturing obtained by cold sheet metal forming a method of automated estimation of technological process reliability was developed. The technique is based on the analysis of reliability factors: detail construction, material, mechanical and physical requirements; hardware settings, tool characteristics, etc. In the work the expert system is presented based on a statistical accumulation of the knowledge of the operator (technologist) and decisions of control algorithms.

  7. Performance Evolution of Phytic Acid Conversion Film in the Forming Process

    OpenAIRE

    Xiufang Cui; Lili Lin; Erbao Liu; Guo Jin; Jie Jin

    2013-01-01

    To improve conversion film techniques, control film properties and improve quality of following techniques, in this study, the environment-friendly phytic conversion films were deposited on AZ91D magnesium alloy. The performance evolution of the film during the forming process such as mechanical property, residual stress, corrosion resistance, micromorphology, composition, and roughness was investigated by nanomechanical testing system, electrochemical workstation, scanning electron microscop...

  8. INVESTIGATION OF A PNEUMO-MECHANICAL HIGH SPEED FORMING PROCESS WITH RESPECT TO THE FORMING OF COMPLEX SHEET AND TUBE COMPONENTS

    OpenAIRE

    Homberg, W.; Djakow, E.; Akst, O.

    2015-01-01

    Lightweight design is playing an increasing role in the automotive and aerospace industries due to the stringent emission regulations. Hence it is necessary to produce parts with complex geometries from sophisticated high-strength materials. In this context, and especially when high strength materials have to be formed into highly complex geometries, it is inevitable that new manufacturing processes will need to be developed which meet these requirements. High speed forming processes have a v...

  9. Use of laser(s) in the process of superplastic forming and diffusion bonding

    Energy Technology Data Exchange (ETDEWEB)

    Jocelyn, A.; Jonik, M.; Keevil, A.; Ackerman, M.; Way, J.; Flower, T. [Aerospace Mfg. Research Centre, Faculty of Computing, Engineering and Mathematical Sciences, Coldharbour Lane, Bristol (United Kingdom); Kar, A. [Univ. of Central Florida, School Optics/CREOL, Orlando, FL (United States)

    2004-07-01

    Superplastic forming and diffusion bonding (SPF/DB) has permitted the manufacture of some of the lightest, strongest, corrosion resistant, complex, and yet often elegant structures ever to be produced. For the last 30 years, all such components have been made by some form of high thermal-mass, isothermal method of production using conventional equipment, such as hot platen presses or furnaces. However, if laser(s) could be used just to heat the material to be superplastically formed, this could provide a novel, low thermal-mass, means of production which could, relatively easily, be integrated into a laser based manufacturing centre. In this paper, a concept is described of how a laser based manufacturing centre, comprised of a number of individual process cells, together with integrated pre and post SPF/DB operations, would work and the benefits that would result. The concept is based on four considerations. Firstly, that it is essential to heat the material directly and quickly. Secondly, the environment must be completely inert so that there is no contamination of components. Thirdly, the complete process of diffusion bonding must only entail the use of laser(s). Lastly, established laser activities such as cutting, welding, hole drilling or trepanning and the removal of surplus material, must be integrated into the process. In addition, the envisaged cells need to be modular in concept so industry can acquire capital plant progressively, thereby spreading the cost over time. (orig.)

  10. Bio-char derived from sewage sludge by liquefaction: Characterization and application for dye adsorption

    Energy Technology Data Exchange (ETDEWEB)

    Leng, Lijian [College of Environmental Science and Engineering, Hunan University, Changsha 410082 (China); Key Laboratory of Environment Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082 (China); Yuan, Xingzhong, E-mail: yxz@hnu.edu.cn [College of Environmental Science and Engineering, Hunan University, Changsha 410082 (China); Key Laboratory of Environment Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082 (China); Huang, Huajun [School of Land Resources and Environment, Jiangxi Agricultural University, Nanchang 330045 (China); Shao, Jianguang; Wang, Hou [College of Environmental Science and Engineering, Hunan University, Changsha 410082 (China); Key Laboratory of Environment Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082 (China); Chen, Xiaohong [School of Business, Central South University, Changsha 410083 (China); Zeng, Guangming [College of Environmental Science and Engineering, Hunan University, Changsha 410082 (China); Key Laboratory of Environment Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082 (China)

    2015-08-15

    Graphical abstract: - Highlights: • SS liquefaction bio-chars were effective on MG and MB removal from aqueous. • MG adsorption capacity depended strongly on carboxylic and phenolic groups. • Metal release accounted for nearly 30% of the total MG adsorbed on bio-chars. • Acetone and low temperature favor effective adsorbent production by liquefaction. - Abstract: Bio-chars produced by liquefaction of sewage sludge with methanol, ethanol, or acetone as the solvent at 260–380 °C were characterized in terms of their elemental composition, thermogravimetric characteristics, surface area and pore size distribution, and oxygen-containing functional groups composition. The surface area and total volume of the bio-chars were low, but the contents of oxygen-containing functional groups were high. The bio-chars were effective on Malachite green (MG) and Methylene blue (MB) removal from aqueous solution. The MG adsorption equilibrium data showed excellent fit to the Langmuir model and the kinetic data fitted well to the Pseudo-second-order model. Thermodynamic investigations indicated that MG adsorption on bio-char was spontaneous and endothermic. The MG adsorption mechanism appears to be associated with cation release and functional group participation. Additionally, liquefaction of SS with acetone as the solvent at low temperature (280 °C) would favor the production of bio-char adsorbent in terms of bio-char yield and MG and MB adsorption capacity.

  11. Bio-char derived from sewage sludge by liquefaction: Characterization and application for dye adsorption

    International Nuclear Information System (INIS)

    Graphical abstract: - Highlights: • SS liquefaction bio-chars were effective on MG and MB removal from aqueous. • MG adsorption capacity depended strongly on carboxylic and phenolic groups. • Metal release accounted for nearly 30% of the total MG adsorbed on bio-chars. • Acetone and low temperature favor effective adsorbent production by liquefaction. - Abstract: Bio-chars produced by liquefaction of sewage sludge with methanol, ethanol, or acetone as the solvent at 260–380 °C were characterized in terms of their elemental composition, thermogravimetric characteristics, surface area and pore size distribution, and oxygen-containing functional groups composition. The surface area and total volume of the bio-chars were low, but the contents of oxygen-containing functional groups were high. The bio-chars were effective on Malachite green (MG) and Methylene blue (MB) removal from aqueous solution. The MG adsorption equilibrium data showed excellent fit to the Langmuir model and the kinetic data fitted well to the Pseudo-second-order model. Thermodynamic investigations indicated that MG adsorption on bio-char was spontaneous and endothermic. The MG adsorption mechanism appears to be associated with cation release and functional group participation. Additionally, liquefaction of SS with acetone as the solvent at low temperature (280 °C) would favor the production of bio-char adsorbent in terms of bio-char yield and MG and MB adsorption capacity

  12. Suspension Combustion of Wood: Influence of Pyrolysis Conditions on Char Yield, Morphology, and Reactivity

    DEFF Research Database (Denmark)

    Dall'Ora, Michelangelo; Jensen, Peter Arendt; Jensen, Anker Degn

    2008-01-01

    Chars from pine and beech wood were produced by fast pyrolysis in an entrained flow reactor and by slow pyrolysis in a thermogravimetric analyzer. The influence of pyrolysis temperature, heating rate and particle size on char yield and morphology was investigated. The applied pyrolysis temperatur...

  13. Thermogravimetric Analysis of Char Waste from the Air Gasification of Empty Fruit Bunch Briquette.

    Directory of Open Access Journals (Sweden)

    Nyakuma Bemgba Bevan

    2014-07-01

    Full Text Available The thermal decomposition behavior of char waste produced from the air gasification of Empty Fruit Bunch (EFB briquette was examined using thermogravimetric analysis (TGA. A comparison between the thermal decomposition behavior of char waste and EFB briquette is also presented. The results indicate that the char waste produced decreased from 22 % to 18 % with increasing temperature from 600 °C to 700 °C during gasification. This is due to the effect of high temperatures on the primary char decomposition reactions. It was observed that char degradation occurs in two steps; char degradation I & II with weight losses of 17 % and 32 % respectively. This showed that only ~ 50 % char was decomposed during thermal analysis, hence higher temperatures are required to ensure complete decomposition. The TGA curve for EFB briquette showed that complete thermal decomposition of EFB briquette occurs in four stages namely; drying, devolatization, reduction and char degradation. The most significant weight loss 2.51 mg or 49.31 % occurred during devolatization.

  14. Study on demetalization of sewage sludge by sequential extraction before liquefaction for the production of cleaner bio-oil and bio-char.

    Science.gov (United States)

    Leng, Lijian; Yuan, Xingzhong; Shao, Jianguang; Huang, Huajun; Wang, Hou; Li, Hui; Chen, Xiaohong; Zeng, Guangming

    2016-01-01

    Demetalization of sewage sludge (SS) by sequential extraction before liquefaction was implemented to produce cleaner bio-char and bio-oil. Demetalization steps 1 and 2 did not cause much organic matter loss on SS, and thus the bio-oil and bio-char yields and the compositions of bio-oils were also not affected significantly. However, the demetalization procedures resulted in the production of cleaner bio-chars and bio-oils. The total concentrations and the acid soluble/exchangeable fraction (F1 fraction, the most toxic heavy metal fraction) of heavy metals (Cu, Cr, Pb, Zn, and Cd) in these products were significantly reduced and the environmental risks of these products were also relived considerably compared with those produced from raw SS, respectively. Additionally, these bio-oils had less heavy fractions. Demetalization processes with removal of F1 and F2 fractions of heavy metals would benefit the production of cleaner bio-char and bio-oil by liquefaction of heavy metal abundant biomass like SS.

  15. Forming characteristics of thin-walled tube bending process with small bending radius

    Institute of Scientific and Technical Information of China (English)

    LI Heng; YANG He; ZHAN Mei; GU Rui-Jie

    2006-01-01

    Currently requirements of thin-walled tube with small bending radius cause the defects such as wrinkling,overthinning and cross-section distortion more prone to occur in bending process. Based on the analysis of the forming characteristics by analytical and experimental methods,a complete 3D elastic-plastic FEM model of the process was developed using ABAQUS/Explicit code,including bending process,balls retracting and unloading process,and thus the plastic deformation characteristics with small bending radius were investigated. The main results show that: 1) The utmost deformation feature of the NC bending process is its continuous progressive deformation. 2) The occurring conditions of the defects such as wrinkling and tension instability in the process are obtained. The wrinkling is traditional on the double compressive stresses state and the tension instability is on the double tension stresses state. 3) The enhanced non-uniform deformation in thin-walled tube with small bending radius is demonstrated by comparing the stress/ strains distributions under the 1.5D and 1D bending conditions. 4) For 1D small bending process,a new method-"stepped mandrel retraction" is proposed to improve the bending quality in experiment according to the FE simulation. The simulation results are verified by experiment.

  16. Research of upsetting ratio in forming processes on a three – slides forging press

    Directory of Open Access Journals (Sweden)

    W.S. Weroński

    2006-04-01

    Full Text Available Purpose: The purpose of the presented in this work research was determining the limiting conditions of upsetting in three-slide forging press (TSFP. The free upsetting process and upsetting process in cylindrical impression were analyzed.Design/methodology/approach: The assumed purpose was confirmed in experimental research. For the case of upsetting in cylindrical impression, the research of limiting upsetting coefficients were made for different diameters and impression lengths. Findings: The obtained results showed large variety of limiting upsetting ratio depending on the analyzed impression geometrical parameters. It was stated, that there are 3 phenomena limiting the upsetting process in the die. The main phenomenon is the bar upsetting outside the impression. The upsetting processes in the impression are limited also by bar buckling outside the impression and overlapping inside the impressionResearch limitations/implications: The results of research allowed for stating that, besides the process geometrical parameters, friction conditions and type of the formed material influenced the limiting upsetting coefficients in the cylindrical impression. It is purposeful to make the further research determining quantitative and qualitative dependencies between these factors. Practical implications: The obtained results are the basis for designing of forming processes in TSFP in which the upsetting dominates. Especially it considers the elongated forgings and elongated preforms with thickeningsOriginality/value: The influence of the impression geometrical parameters on the limiting upsetting coefficients for the case of upsetting in cylindrical impression in TSFP has been analyzed in details. The dependencies, which should be used during designing of upsetting processes in TSFP were determined.

  17. PROPERTIES OF GAS AND CHAR FROM MICROWAVE PYROLYSIS OF PINE SAWDUST

    Directory of Open Access Journals (Sweden)

    Xian-Hua Wang

    2009-08-01

    Full Text Available Pine sawdust pyrolysis was carried out respectively using microwave and conventional electrical heating at different temperatures in order to understand the properties of pyrolytic products from microwave pyrolysis of biomass. Less char material was obtained by microwave pyrolysis compared to conventional heating at the same temperature. While comparing the components of the pyrolytic gases, it was revealed that the microwave pyrolysis gas usually had higher H2 and CO contents and lower CH4 and CO2 contents than those obtained by conventional pyrolysis at the same temperature. The texture analysis results of the microwave pyrolysis chars showed that the chars would melt and the pores would shrink at high temperatures, and hence, the specific surface areas of the chars decreased with increasing temperature. Similarly, the reactivity of the char was remarkably reduced when the microwave pyrolysis temperature exceeded 600°C.

  18. Investigating the morphology and reactivity of chars from Triplochiton scleroxylon pyrolysed under varied conditions.

    Science.gov (United States)

    Oluoti, Kehinde; Pettersson, Anita; Richards, Tobias

    2016-05-01

    A gasifier may be optimised via a good understanding of the char formation, morphology and reactivity. The effects of varying the pyrolysis pressure and heating rate on the morphology of the char were investigated using a thermogravimetric analyser (TGA), scanning electron microscope (SEM) and micrograph spot analyser. The gasified chars were produced at heating rates of 5, 10 and 20°C/min and pressures of 0.1, 0.4 and 0.6 MPa. All the chars have different degrees of apparent gasification reactivity. The random pore model (RPM) provided a better description of the experiment, with low average error values, θ, in all of the cases considered. The alkaline and alkaline earth metals (AAEM) in the tropical wood biomass Arere (Triplochiton scleroxylon) consist predominantly of calcium and could altogether be partly responsible for the noticeably high reactivity nature of the tropical Arere chars. PMID:26926201

  19. Forms And Methods Of Modern Russian Youth Involvement Into The Electoral Process

    Directory of Open Access Journals (Sweden)

    Aleksey D. Maslov

    2015-03-01

    Full Text Available In the present article authors analyzes forms and methods of modern Russian youth involvement in the electoral process. Involving young people in the electoral process is directly related to the problem of increasing the level of political culture in the society. This article presents the main forms of work to attract young people to participate in elections in our country, according to the Central Election Commission (CEC of Russia, some of the regional election commissions, the Russian Public Opinion Research Center (WCIOM. Authors note that at present there are more than one hundred and sixty legislative acts of the Russian Federation, which reflect certain aspects of the state youth policy. All these measures stimulate the political activity of young people, but in our opinion, that is not enough. The fundamental change in the attitude of young people to politics, to the institution of elections is possible only when young people feel like a real part and the subject of transformation processes in our country. In conclusion authors summarizes, that a fundamental change in the relationship of young people to politics, the institution of elections is possible only, when very young feel a real party and the subject of transformation processes in our country. This is possible only when the state is really and not formally prioritizes youth policy. Young people should have a daily state support for education, starting a business, implementation of acquired skills for a decent fee, starting a family, buying a house, etc.

  20. Characterisation and reaction kinetics of high ash chars derived from inertinite-rich coal discards / Rufaro Kaitano

    OpenAIRE

    Kaitano, Rufaro

    2007-01-01

    An investigation was undertaken to determine the gasification and combustion characteristics of chars derived from an inertinite-rich coal discard sample with a high ash content. Fundamental knowledge of the reaction rate kinetics for char conversion at reactions conditions used in fluidised bed gasification and combustion was obtained. For this purpose, characterisation of the parent coal and derived chars, reactivity determinations of the chars and detailed reaction rate mode...

  1. Chars produced by slow pyrolysis and hydrothermal carbonization vary in carbon sequestration potential and greenhouse gases emissions

    OpenAIRE

    Malghani, S; G. Gleixner; Trumbore, SE, Reichstein, M.

    2013-01-01

    Bio-char, biomass that has been deliberately charred to slow its rate of decomposition, has been proposed as an amendment with the potential to sequester carbon and improve certain soil properties. Slow pyrolysis (temperature ≤500°C) and hydrothermal carbonization (low temperature, high pressure) are two efficient methods to produce bio-char with high yield and are applicable to a broad range of feedstocks. Chars made using slow pyrolysis (PC) and hydrothermal carbonization (HTC) of the same ...

  2. Membrane loop process for separating carbon dioxide for use in gaseous form from flue gas

    Energy Technology Data Exchange (ETDEWEB)

    Wijmans, Johannes G; Baker, Richard W; Merkel, Timothy C

    2016-09-06

    The invention is a process involving membrane-based gas separation for separating and recovering carbon dioxide emissions from combustion processes in partially concentrated form, and then transporting the carbon dioxide and using or storing it in a confined manner without concentrating it to high purity. The process of the invention involves building up the concentration of carbon dioxide in a gas flow loop between the combustion step and a membrane separation step. A portion of the carbon dioxide-enriched gas can then be withdrawn from this loop and transported, without the need to liquefy the gas or otherwise create a high-purity stream, to a destination where it is used or confined, preferably in an environmentally benign manner.

  3. Controlled FEM simulation ways of blank holding force in sheet metal forming process

    International Nuclear Information System (INIS)

    A new scheme for blank holding force (BHF) is introduced in order to apply more realistic BHF in simulation. The present study has been carried out for deep drawing processes of a washing-trough. Different blankholder gaps and separation forces simulate the blank holding process. The optimum blankholder gap and separation force are determined through a systematic approach. It is found that the wrinkling in the flange region of the blank increases with the augmentation of the blank holder gap. And the BHF increases owing to the elevation of the rigidity of the sheet metal. The simulated thickness with separation force is lower than that with the blankholder gap because the BHF is variable in the flange region. A comparison of the thickness and flange contour between the simulation results and experiment shows that the blankholder gap is better in the simulation of the BHF in sheet metal forming process

  4. The thermal stability and pyrolysis mechanism of boron-containing phenolic resins: The effect of phenyl borates on the char formation

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Shujuan; Wang, Yong; Bian, Cheng; Zhong, Yuhu [Department of Applied Chemistry, School of Science, Xi’an Jiaotong University, Xi’an 710049, People’ s Republic of China (China); Jing, Xinli, E-mail: rgfp-jing@mail.xjtu.edu.cn [Department of Applied Chemistry, School of Science, Xi’an Jiaotong University, Xi’an 710049, People’ s Republic of China (China); MOE Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed Matter, Xi’an, 710049, People’ s Republic of China (China)

    2015-03-15

    Graphical abstract: - Highlights: • The thermal stability and pyrolysis mechanism of cured BPR are investigated. • The high char yield of BPR results from the formed phenyl borates during curing. • Boron oxide is formed on the surface of carbonized product during pyrolysis. • The formed boron oxide revealed the cleavage of O–C bonds from phenyl borates. • The graphitization degree and graphite crystallites of PR are improved by introducing boron. - Abstract: Boron-containing phenolic resin (BPR) is a kind of the ablative resins with high-performance. Due to the lack of the exact knowledge concerning the pyrolysis mechanism of BPR, its development and application are greatly impeded. In the present paper, the chemical structure of the cured BPR and its structural evolution at high temperatures are investigated to clarify the reason for the high char yield of BPR. The results indicate that the high char yield of BPR is mainly attributed to the phenyl borates formed during curing, which can block parts of phenolic hydroxyl groups, and effectively inhibit their thermal decomposition reaction. Boron oxide is formed on the surface of carbonization products by the cleavage of O–C bonds from phenyl borates via pyrolysis, which avoids the release of volatile carbon dioxide and reduces the development of micro-structural defects of carbonization products. Introducing boron into PR improves the graphitization degree and graphite crystallites of carbonization products, which promotes the formation of a more ordered glassy carbon during pyrolysis. This study provides a new vision for the understanding of the high char yield of BPR, which makes it possible to develop a new ablative resin through molecular design.

  5. Rheology as a tool for evaluation of melt processability of innovative dosage forms.

    Science.gov (United States)

    Aho, Johanna; Boetker, Johan P; Baldursdottir, Stefania; Rantanen, Jukka

    2015-10-30

    Future manufacturing of pharmaceuticals will involve innovative use of polymeric excipients. Hot melt extrusion (HME) is an already established manufacturing technique and several products based on HME are on the market. Additionally, processing based on, e.g., HME or three dimensional (3D) printing, will have an increasingly important role when designing products for flexible dosing, since dosage forms based on compacting of a given powder mixture do not enable manufacturing of optimal pharmaceutical products for personalized treatments. The melt processability of polymers and API-polymer mixtures is highly dependent on the rheological properties of these systems, and rheological measurements should be considered as a more central part of the material characterization tool box when selecting suitable candidates for melt processing by, e.g., HME or 3D printing. The polymer processing industry offers established platforms, methods, and models for rheological characterization, and they can often be readily applied in the field of pharmaceutical manufacturing. Thoroughly measured and calculated rheological parameters together with thermal and mechanical material data are needed for the process simulations which are also becoming increasingly important. The authors aim to give an overview to the basics of rheology and summarize examples of the studies where rheology has been utilized in setting up or evaluating extrusion processes. Furthermore, examples of different experimental set-ups available for rheological measurements are presented, discussing each of their typical application area, advantages and limitations. PMID:25666026

  6. FEM-based strain analysis study for multilayer sheet forming process

    Science.gov (United States)

    Zhang, Rongjing; Lang, Lihui; Zafar, Rizwan

    2015-12-01

    Fiber metal laminates have many advantages over traditional laminates (e.g., any type of fiber and resin material can be placed anywhere between the metallic layers without risk of failure of the composite fabric sheets). Furthermore, the process requirements to strictly control the temperature and punch force in fiber metal laminates are also less stringent than those in traditional laminates. To further explore the novel method, this study conducts a finite element method-based (FEM-based) strain analysis on multilayer blanks by using the 3A method. Different forming modes such as wrinkling and fracture are discussed by using experimental and numerical studies. Hydroforming is used for multilayer forming. The Barlat 2000 yield criteria and DYNAFORM/LS-DYNA are used for the simulations. Optimal process parameters are determined on the basis of fixed die-binder gap and variable cavity pressure. The results of this study will enhance the knowledge on the mechanics of multilayer structures formed by using the 3A method and expand its commercial applications.

  7. Rock weathering Tendency at Different Stages of Soil—Forming Processes in Fildes Peninsula,Antarctic

    Institute of Scientific and Technical Information of China (English)

    CHENJIE; GONGZITONG

    1996-01-01

    From the view of energy state of material,this paper introduces a concept a concept of weathering potential in carrying out quantitative calculation of the relevant products at different stages of rock-weathering and primary soil-forming processes,elaborates respectively on weathering degree in the bio-weathering layer of rocks and during the formation of soil material and clay,and evaluats the further tendency of weathering in the above-mentioned stages.The authors have discovered that the scales of weathering potential of the materials increase successively in the three stages,which indicates that the products in the above-mentioned three stages must have undergone stronger and stronger weathering in the primitive forming process of soil in Fildes Peninsula,Antarctic.But,Because of relatively weak chemical weathering,it is reasonable that there are much more skeleton grains and little clay in priamry soils in this region.Meanwhile the authors have also verified that the weathering potential of crde rock determines to some extent decrease in the products' weathering potential in the different stages in primary soil-forming,thereby plays an important role in the genesis and development of the primary soil in the studied area.

  8. Polyethylene encapsulatin of nitrate salt wastes: Waste form stability, process scale-up, and economics

    International Nuclear Information System (INIS)

    A polyethylene encapsulation system for treatment of low-level radioactive, hazardous, and mixed wastes has been developed at Brookhaven National Laboratory. Polyethylene has several advantages compared with conventional solidification/stabilization materials such as hydraulic cements. Waste can be encapsulated with greater efficiency and with better waste form performance than is possible with hydraulic cement. The properties of polyethylene relevant to its long-term durability in storage and disposal environments are reviewed. Response to specific potential failure mechanisms including biodegradation, radiation, chemical attack, flammability, environmental stress cracking, and photodegradation are examined. These data are supported by results from extensive waste form performance testing including compressive yield strength, water immersion, thermal cycling, leachability of radioactive and hazardous species, irradiation, biodegradation, and flammability. The bench-scale process has been successfully tested for application with a number of specific ''problem'' waste streams. Quality assurance and performance testing of the resulting waste form confirmed scale-up feasibility. Use of this system at Rocky Flats Plant can result in over 70% fewer drums processed and shipped for disposal, compared with optimal cement formulations. Based on the current Rocky Flats production of nitrate salt per year, polyethylene encapsulation can yield an estimated annual savings between $1.5 million and $2.7 million, compared with conventional hydraulic cement systems. 72 refs., 23 figs., 16 tabs

  9. MCF (Magnetic Compound Fluid) Polishing Process for Free-formed Resin Device using Robotic Arm

    Science.gov (United States)

    Wu, Y.; Sato, T.; Lin, W.; Yamamoto, K.; Shimada, K.

    2011-01-01

    The automatic polishing process for three-dimensional forms, such as prototype models of products made of acrylic resin, are being required to develop in order to reduce cost and time consumption. This paper proposes a new polishing technique using magnetic compound fluid (MCF) and robotic arm. Firstly, a polishing unit, which can generate a dynamic magnetic field and be attachable to the robotic arm, is developed. This unit can hold MCF slurry that acts as a flexible and restorable polishing tool for the sake of magnetic force. Secondly, the effects of the clearance between workpiece and polishing unit, the composition of MCF slurry, the relative motion, the dynamic magnetic field and the supplied amount of slurry on polishing characteristics of acrylic resin are experimentally demonstrated. As a result, the smoothest surface roughness is achieved to below 10 nm Ra in a few min, and the feasibility of polishing the free-formed device by controlling robotic arm has been confirmed.

  10. Effect of Deformation Condition on Axial CompressivePrecision Forming Process of Tube with Curling Die

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The effect of the deformation condition on the axial compressive precision forming process of tube with curling die was investigated by using a rigid-plastic FEM. The results show that the forming accuracy depends mainly on geometric condition rρ/d0, little on tube material properties and friction condition; the relative gap Δ/2rρ of double-walled tubes obtained decreases with increasing rρ/d0, and there is a parameter k for a given t0/d0 or rρ/t0, when rρ,/d0>k, Δ/2rρ<1,otherwise Δ/2rρ>1.

  11. Biological processes controlling the development of modern peat-forming ecosystems

    Energy Technology Data Exchange (ETDEWEB)

    Moore, P.D. [University of London, London (United Kingdom). Division of Life Sciences

    1995-11-01

    Although no precise modern analogue exists for the peat-forming ecosystems (mires) of Tertiary times, it is argued that the principles underlying peat formation are essentially unchanged in the sense that a peat-forming ecosystem has an incomplete decomposition process (normally because of water-logging), leaving a residue of organic material in its overall energy-flow budget. The study of modern mires is therefore of relevance to Tertiary coal geologists. The classification of modern mires is best achieved by reference to their hydrological characteristics, particularly the source of water entering the system. Flow-fed (rheotrophic) mires are often relatively rich in nutrients and clastic, while rain-fed (ombrotrophic) mires are poor. The transition from one hydrological state to the other can occur during mire development and involves a physical elevation of the mire surface by the growth of peat. 29 refs., 4 figs.

  12. Population connectivity: dam migration mitigations and contemporary site fidelity in arctic char

    Directory of Open Access Journals (Sweden)

    Heggenes Jan

    2011-07-01

    Full Text Available Abstract Background Animal feeding and spawning migrations may be limited by physical barriers and behavioral interactions. Dam constructions (e.g. hydropower commonly include gateways for fish migrations to sustain ecological connectivity. Relative genetic impacts of fish passage devices versus natural processes (e.g. hybrid inferiority are, however, rarely studied. We examined genetic (i.e. microsatellite population connectivity of highly migrating lake-dwelling Arctic char (Salvelinus alpinus, introduced 20 generations ago, across and within two subalpine lakes separated by a dam with a subterranean tunnel and spill gates after 7 generations. Due to water flow regime, the time window for fish migration is highly restricted. Results Char populations, with similar genetic structuring and diversity observed across and within lakes, were admixed across the dam with fishways during feeding. For spawning, however, statistically significant, but very low population differentiation (θ; 0.002 - 0.013 was found in nine out of ten reproductive site comparisons, reflecting interactions between extensive migration (mean first generation (F0 = 10.8% and initial site fidelity. Simulations indicated that genetic drift among relatively small effective populations (mean Ne = 62 may have caused the observed contemporary differentiation. Novel Bayesian analyses indicated mean contributions of 71% F0 population hybrids in spawning populations, of which 76% had maternal or paternal native origin. Conclusions Ecological connectivity between lakes separated by a dam has been retained through construction of fishways for feeding migration. Considerable survival and homing to ancestral spawning sites in hybrid progeny was documented. Population differentiation despite preceding admixture is likely caused by contemporary reduced reproductive fitness of population hybrids. The study documents the beginning stages of population divergence among spatial aggregations with

  13. Hygiene Aspects of the Biogas Process with Emphasis on Spore-Forming Bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Bagge, Elisabeth

    2009-07-01

    Biogas is a renewable source of energy which can be obtained from processing of biowaste. The digested residues can be used as fertiliser. Biowaste intended for biogas production contains pathogenic micro-organisms. A pre-pasteurisation step at 70 deg C for 60 min before anaerobic digestion reduces non spore-forming bacteria such as Salmonella spp. To maintain the standard of the digested residues it must be handled in a strictly hygienic manner to avoid recontamination and re-growth of bacteria. The risk of contamination is particularly high when digested residues are transported in the same vehicles as the raw material. However, heat treatment at 70 deg C for 60 min will not reduce spore-forming bacteria such as Bacillus spp. and Clostridium spp. Spore-forming bacteria, including those that cause serious diseases, can be present in substrate intended for biogas production. The number of species and the quantity of Bacillus spp. and Clostridium spp. in manure, slaughterhouse waste and in samples from different stages during the biogas process were investigated. The number of species of clostridia seemed to decrease following digestion, likewise the quantity. However, Bacillus spp. seemed to pass unaffected through the biogas process. In laboratory-scale experiments the effects on clostridia during pasteurisation and digestion were investigated. Pathogenic clostridia were inoculated in substrates from homogenisation tanks and digester tanks. The inoculated clostridia remained after pasteurisation, but the impacts of digestion differ between different species. Culture followed by identification of C. chauvoei by PCR in samples from cattle died from blackleg, is faster and safer than culture followed by biochemical identification of C. chauvoei. However, for environmental samples the PCR method is not practically applicable for detection of C. chauvoei. To avoid spreading of diseases via biogas plants when digested residues are spread on arable land, a pasteurisation

  14. The removal of reactive dyes using high-ash char

    Directory of Open Access Journals (Sweden)

    Moreira R.F.P.M.

    2001-01-01

    Full Text Available The thermodynamics and kinetics of adsorption of reactive dyes on high-ash char was studied. Equilibrium data were obtained using the static method with controlled agitation at temperatures in the range of 30 to 60ºC. The Langmuir isotherm model was used to describe the equilibrium of adsorption, and the equilibrium parameters, R L, in the range of 0 to 1 indicate favorable adsorption. The amount of dye adsorbed increased as temperature increased from 30 to 40ºC, but above 40ºC the increase in temperature resulted in a decrease in the amount of dye adsorbed. The kinetic data presented are for controlled agitation at 50 rpm and constant temperature with dye concentrations in the range of 10 ppm to50 ppm. The film mass transfer coefficient, Kf, and the effective diffusivity inside the particle, De, were fitted to the experimental data. The results indicate that internal diffusion governs the adsorption rate.

  15. Spray Deposition Behavior and Numerical Simulation of Growth of Tubular Preform in Spray Forming Process

    Institute of Scientific and Technical Information of China (English)

    XIANG Jin-zong; ZHANG Yin; FAN Wen-jun; WANG Ping; HE You-duo

    2012-01-01

    Analysis on the deposition behavior of spray on deposition surface was made and an optimization method for the movement parameters (u, ω) of substrate was obtained. Simultaneously, a mathematical model of growth of tubular preform, specifically aimed at the kind of atomizer that is fixed and with a tilt angle was established. By in- tegrating the optimization method and the mathematical model, the growth process and shape of preform were simu- lated. The results show that the tilt angle of atomizer plays an important role on the dimensions and shapes of tubular preforms and it can provide a guidance for the development of spray forming equipment.

  16. Working Place as an Organisational Form of the Process of Labour

    Directory of Open Access Journals (Sweden)

    Amosov Oleg Yu.

    2013-11-01

    Full Text Available In order to achieve efficient functioning of modern production based on application of complex equipment and technology, which is characterised with a big number of internal production links, it is necessary to have an accurate organisation of the working place. The article considers the working place notion not from the position of a portion of space, which is adjusted for performance of production functions by a worker, but as an organisational form of the process of labour, which integrates its following components: organisational, technical, economic, social security of labour and intellectualisation of labour.

  17. An Integrated Approach for the Numerical Modelling of the Spray Forming Process

    DEFF Research Database (Denmark)

    Hattel, Jesper; Thorborg, Jesper; Pryds, Nini;

    2003-01-01

    of the deposition is accomplished using a 3-D cylindrical heat flow model. This model is now coupled with an atomization model via a log-normal droplet size distribution. The coupling between the atomization and the deposition model is accomplished by ensuring that the total droplet size distribution of the spray......In this paper, an integrated approach for modelling the entire spray forming process is presented. The basis for the analysis is a recently developed model which extents previous studies and includes the interaction between an array of droplets and the enveloping gas. The formulation...

  18. Possible method to measure the ratio of proton form factors in processes with proton spin transmission

    CERN Document Server

    Galynsky, M V; Bystritskiy, Yu M

    2008-01-01

    The ratio of squared of electric and magnetic form-factor of proton is shown to be proportional to the ratio of flip and non-flip cross section of elastic electron polarized proton scattering. Spin-flip (non-spin-flip) cross section correspond to the case when polarization of recoil proton antiparallel (parallel) to the polarization of initial proton when polarization of initial proton is parallel to tree momentum scattered proton. A similar arguments are valid for radiative ep-scattering as well as for the crossed process pair photo-production on the polarized proton in Bethe-Heitler kinematics.

  19. Acquisition of material properties in production for sheet metal forming processes

    Science.gov (United States)

    Heingärtner, Jörg; Neumann, Anja; Hortig, Dirk; Rencki, Yasar; Hora, Pavel

    2013-12-01

    In past work a measurement system for the in-line acquisition of material properties was developed at IVP. This system is based on the non-destructive eddy-current principle. Using this system, a 100% control of material properties of the processed material is possible. The system can be used for ferromagnetic materials like standard steels as well as paramagnetic materials like Aluminum and stainless steel. Used as an in-line measurement system, it can be configured as a stand-alone system to control material properties and sort out inapplicable material or as part of a control system of the forming process. In both cases, the acquired data can be used as input data for numerical simulations, e.g. stochastic simulations based on real world data.

  20. Organic structure and possible origin of ancient charred paddies at Chuodun Site in southern China

    Institute of Scientific and Technical Information of China (English)

    HU LinChao; LI Xia; LIU BenDing; GU Min; DAI JingYu

    2009-01-01

    A number of ancient charred paddies with a 14C dating of about 5900 a BP were recovered in the sixthexcavation at Chuodun Site and are assigned to the Majiabang culture (7-6 ka BP). To understand their formation mechanism, the ancient charred paddies were compared to modern paddies using FT-IR spectrum and thermaogravimetric analysis. At the same time, modern charred paddies were made in helium by the laboratory method, and the structural characteristics of them and the ancient ones were revealed using CP/MAS-13C-NMR. Our results show there are more aromatic moieties in ancient charred paddies compared to modern paddies. The aliphatic components of modern charred paddies decreasecontinuously, accompanied by the accumulation of aromatic components, when the duration and temperature of oxidation increase, and the structure buildings of modern charred paddies are more similar to ancient ones. Given the planting manner of paddies during Majiabang culture period, these ancient charred paddies might be a result of the original farming mode involving fire.

  1. Organic structure and possible origin of ancient charred paddies at Chuodun Site in southern China

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    A number of ancient charred paddies with a 14C dating of about 5900 a BP were recovered in the sixth excavation at Chuodun Site and are assigned to the Majiabang culture(7-6 ka BP).To understand their formation mechanism,the ancient charred paddies were compared to modern paddies using FT-IR spectrum and thermaogravimetric analysis.At the same time,modern charred paddies were made in helium by the laboratory method,and the structural characteristics of them and the ancient ones were revealed using CP/MAS-13C-NMR.Our results show there are more aromatic moieties in ancient charred paddies compared to modern paddies.The aliphatic components of modern charred paddies decrease continuously,accompanied by the accumulation of aromatic components,when the duration and temperature of oxidation increase,and the structure buildings of modern charred paddies are more similar to ancient ones.Given the planting manner of paddies during Majiabang culture period,these ancient charred paddies might be a result of the original farming mode involving fire.

  2. Effects of Biomass Feedstocks and Gasification Conditions on the Physiochemical Properties of Char

    Directory of Open Access Journals (Sweden)

    Raymond L. Huhnke

    2013-08-01

    Full Text Available Char is a low-value byproduct of biomass gasification and pyrolysis with many potential applications, such as soil amendment and the synthesis of activated carbon and carbon-based catalysts. Considering these high-value applications, char could provide economic benefits to a biorefinery utilizing gasification or pyrolysis technologies. However, the properties of char depend heavily on biomass feedstock, gasifier design and operating conditions. This paper reports the effects of biomass type (switchgrass, sorghum straw and red cedar and equivalence ratio (0.20, 0.25 and 0.28, i.e., the ratio of air supply relative to the air that is required for stoichiometric combustion of biomass, on the physiochemical properties of char derived from gasification. Results show that the Brunauer-Emmett-Teller (BET surface areas of most of the char were 1–10 m2/g and increased as the equivalence ratio increased. Char moisture and fixed carbon contents decreased while ash content increased as equivalence ratio increased. The corresponding Fourier Transform Infrared spectra showed that the surface functional groups of char differed between biomass types but remained similar with change in equivalence ratio.

  3. Feasibility of mercury removal from simulated flue gas by activated chars made from poultry manures

    Energy Technology Data Exchange (ETDEWEB)

    Klasson, K.T.; Lima, I.M.; Boihem, L.L.; Wartelle, L.H. [USDA, New Orleans, LA (United States)

    2010-12-15

    Increased emphasis on reduction of mercury emissions from coal fired electric power plants has resulted in environmental regulations that may in the future require application of activated carbons as mercury sorbents for mercury removal. At the same time, the quantity of poultry manure generated each year is large and technologies that take advantage of the material should be explored. The purpose of the work was to obtain preliminary data to investigate if activated chars made from different poultry manures could adsorb mercury from simulated flue gas. In laboratory experiments, activated chars made from chicken cake and litter removed mercury from the gas as well as a commercial alternative. It was also found that acid-washing these chars after activation may improve pore structure but does not influence the mercury removal efficiency. Activated chars were also made from turkey cake and litter. These raw materials produced activated chars with similar pore structure as those made from chicken manure, but they did not adsorb mercury as well. Acid-washing the turkey manure-based chars improved their performance, but this step would add to the cost of production. Preliminary evaluations suggest that unwashed activated chars may cost as little as $0.95/kg to produce.

  4. Leaching behaviour and ecotoxicity evaluation of chars from the pyrolysis of forestry biomass and polymeric materials.

    Science.gov (United States)

    Bernardo, M; Mendes, S; Lapa, N; Gonçalves, M; Mendes, B; Pinto, F; Lopes, H

    2014-09-01

    The main objective of this study was to assess the environmental risk of chars derived from the pyrolysis of mixtures of pine, plastics, and scrap tires, by studying their leaching potential and ecotoxicity. Relationships between chemical composition and ecotoxicity were established to identify contaminants responsible for toxicity. Since metallic contaminants were the focus of the present study, an EDTA washing step was applied to the chars to selectively remove metals that can be responsible for the observed toxicity. The results indicated that the introduction of biomass to the pyrolysis feedstock enhanced the acidity of chars and promote the mobilisation of inorganic compounds. Chars resulting from the pyrolysis of blends of pine and plastics did not produce ecotoxic eluates. A relationship between zinc concentrations in eluates and their ecotoxicity was found for chars obtained from mixtures with tires. A significant reduction in ecotoxicity was found when the chars were treated with EDTA, which was due to a significant reduction in zinc in chars after EDTA washing. PMID:24905691

  5. Disaster forming reasons on fire explosion at an asphalt solidification processing facility

    International Nuclear Information System (INIS)

    Disaster forming reasons on fire explosion accident at an asphalt solidification processing facility of the Power Reactor and Nuclear Fuel Development Corporation formed on 1997 was elucidated. Mixture of salts composing of nitrates, nitrites, and so on with asphalt was filled into a drum at about 180 centigrade, and generated disaster during its natural cooling after about 20 hours. Its reason consisted in change of production condition to make liquid wastes of batches 29 and 30 producing the mixture to contain about 7.7 g/L of salts and liquid wastes supplying rate to reduce to about 160 mL/h. The liquid wastes were mixed with asphalt heated to temperature of about 250 centigrade, when it contained a lot of NaHCO3 into the salts particles on filling the mixture because moisture was evaporated more rapidly under pressure of phosphates based on the change of production condition. NaHCO3 directly decomposed to make the salts particles porous and to form a weak redox reaction based on boundary reaction appearing at temperature range from 160 to 200 centigrades. By this reaction, the mixture filled into drum generated thermal accumulation to fire the mixture. (G.K.)

  6. THE PROCESSING STEPS IN THE RENEW OF PLUG-FORMING DETAILS OF PIPELINE FITTINGS

    Directory of Open Access Journals (Sweden)

    Vladimir A. Skryabin

    2016-06-01

    Full Text Available Introduction. In production and repairs of pipeline armature grinding (debugging is considered as one of the major technological operations. The main task is the providing of impermeability of breech-block. Whatever problems did not arise up in the achievement of impermeability, diagnosis of reason, practically, always one - the process of grinding in of fine surfaces is well not enough conducted. There is a large stake of truth in such answer, however, its not all and problem not only in grinding in. Grinding in is the finish operation of polishing of compressions and effective of its application depends not only on the exact observance of the recommended terms and modes of process. A major value of the the stages is the forming of quality and preceding to grinding in of the operation of treatment of compressions. If prior actions are executed off grade, then efficiency of realization of portable radio operations of grinding in will be. Materials and Methods. To the article a growing requirement is driven in the improvement of quality, increment of productivity and increment of longevity and reliability of machines and wares. The process of grinding (polishing in allows to get the surfaces of processed details with high quality descriptions. Quality of implementation of finishing operation is estimated on following criteria: it is exactly in size, it is an error of form, they are indices of waviness of surface, indices of roughness of surface, the light reflect¬ing ability and quality descriptions of surface layer. For renewal of corps of wedge bolt by a main task providing of impermeability of breech-block. For its implementation hard requirements are produced, namely; a small roughness of surface, form and location. Thus fine surface of corps of wedge bolt must be homogeneous. Results. In order to attain the set roughness of fine surface, the trajectory of motion of instrument must have certain character. Because on this machine-tool a

  7. Preliminary Study on Element Leaching and Current Soil—Forming Process of Red Soils

    Institute of Scientific and Technical Information of China (English)

    ZHANQI-GUO; XUESHI-KUI; 等

    1991-01-01

    The leaching characteristics and the element concentration in soil solution of red soils derived from sandstone,granite,Quaternary red clay and basalt have been studied in the Red Earth Ecological Experimental Station,Academia Sinica,using 12 lysimeters.Results obtained show that the element leaching process of red soils occurs mainly from January to the beginning of July annually.The elements with higher concentration in leaching solution of red soils are Si,Ca,Na,K,Mg,and N.The desilication and the leaching process of base cations occur simultaneously in the red soils.Using the first order differential equation and measured parameters of Si leaching,the leaching models of Si for red soils derived from different parent materials are constructed.The leaching process of Si is simulated with the models.Both the absolute and relative ages of red soils derived from different parent materials are discussed based on the simulation result.On the basis of element leaching,composition of soil solution and thermodynamics,the current soil-forming process is discussed.According to the phase diagram,the kaolinization is prevailing in the current formation of different red soils.

  8. Forming Conditions and Neural Network Control of Continuously Directional Microstructure in Directional Solidification Continuous Casting Process

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    Directional solidification continuous casting (DSCC) process is a new manufacturing technology for metal- lic materials which combines advantages of both directional solidification technology and continuous casting technolo- gy. Unlimited long shaped metal with directionally solidifying microstructure can be produced by this process. It is experimentally shown that controlling condition of stable and continuous growth of single crystal structure means the precise control of the location of the S/L interface, which is affected and determined by seven process parameters. Moreover, these parameters are also interacted each other, so the disturbance of any parameters may cause the fail- ure of controlling of S/L interface. In this paper, on the basis of analyzing the forming conditions of continuously di- rectional microstructures in DSCC process, the control model of DSCC procedure by neural network control (NNC) method was proposed and discussed. Combining with the experiments, we first used the computer to simulate the effects of the solidification parameters on destination control variable (S/L interface) and the interactions among these parameters during DSCC procedure. Secondly many training samples necessary for neural network calculation can be obtained through the simulation. Moreover, these samples are inputted into neural network software (NNs) and trained, then the control model can be built up.

  9. Study on Pot Forming of Induction Heater Type Rice Cookers by Forging Cast Process

    Science.gov (United States)

    Ohnishi, Masayuki; Yamaguchi, Mitsugi; Ohashi, Osamu

    This paper describes a study result on pot fabrication by the forging cast process of stainless steel with aluminum. Rice cooked with the new bowl-shaped pot for the induction heater type rice cookers is better tasting than rice cooked with the conventional cylindrical one, due to the achievement of better heat conduction and convection. The conventional pot is made of the clad sheet, consisting of stainless steel and aluminum. However, it is rather difficult to form a bowl shape from the clad sheet, primarily due to the problem of a material spring back. The fabrication of a new type of a pot was made possible by means of the adoption of a forging cast process instead of the clad sheet. In this process, iron powder is inserted between stainless steel and aluminum in order to alleviate the large difference on the coefficient of expansion between each material. It was made clear that the application of two kinds of iron particle, namely 10 μm size powder on the stainless steel side and 44 μm on the aluminum side, enables the joints to become strong enough. The joint strength of the new pot by this fabrication process was confirmed by the tests of the shear strength and the fatigue tests together with the stress analysis.

  10. Multi-objective optimization of stamping forming process of head using Pareto-based genetic algorithm

    Institute of Scientific and Technical Information of China (English)

    周杰; 卓芳; 黄磊; 罗艳

    2015-01-01

    To obtain the optimal process parameters of stamping forming, finite element analysis and optimization technique were integrated via transforming multi-objective issue into a single-objective issue. A Pareto-based genetic algorithm was applied to optimizing the head stamping forming process. In the proposed optimal model, fracture, wrinkle and thickness varying are a function of several factors, such as fillet radius, draw-bead position, blank size and blank-holding force. Hence, it is necessary to investigate the relationship between the objective functions and the variables in order to make objective functions varying minimized simultaneously. Firstly, the central composite experimental (CCD) with four factors and five levels was applied, and the experimental data based on the central composite experimental were acquired. Then, the response surface model (RSM) was set up and the results of the analysis of variance (ANOVA) show that it is reliable to predict the fracture, wrinkle and thickness varying functions by the response surface model. Finally, a Pareto-based genetic algorithm was used to find out a set of Pareto front, which makes fracture, wrinkle and thickness varying minimized integrally. A head stamping case indicates that the present method has higher precision and practicability compared with the“trial and error”procedure.

  11. Role of Lichens in Weathering and Soil—Forming Processes in Fildes Peninsula,Antarctic

    Institute of Scientific and Technical Information of China (English)

    CHENJIE; GONGZi-TONG

    1995-01-01

    Lichens play an unparalleledly vital role in weathering and soil-forming processes in Antarctic region,In this study some related chemical components and micromorphological analyses have been carried out on the samples of the weathered rocks and the lichens grown on them from Files Peninsula,Antarctic,The results indicatied that the major chemical components in the bioweathering surface layer of the sampled rocks have been obviously altered and the weathering potential in this layer has greatly decreased by and average range around 4.66 percent in 4 samples,In the weathering surface layer ferruginiztion of some minerals in varying degress was seen by means of microscopic examination through the thin section of the weathered rocks,and its products proved to be dominated by hematitie,limonite,goethite and free iron oxides Meanwhile,the study suggested that the dissolution and absorption of lichens by their secretion accelerated the process of calcitization of minerals in the bio-weathering suface layer,Eventually,the results also show that different species of lichens play different roles in weathering and soil-forming proesses.

  12. A Model-based Phenomenological Investigation of Char Combustion Kinetics through Thermogravimetry

    Institute of Scientific and Technical Information of China (English)

    Qun CHEN; Rong HE; Zhan Gang LIANG; Xu Chang XU; Chang He CHEN

    2005-01-01

    Five coal char samples were burnt in thermobalance with ramp heating rate of 30 K/min.The pore structure of these char samples was studied through mercury intrusion method.Combined with the kinetic theory of gases, the data of surface area was used in fitting the results.As a result, the kinetic triplet was given. The analysis showed that five char samples share almost the same intrinsic activation energy of the overall reaction. The phenomenological implication of the derived combustion rate equation was given.

  13. Near net shape forming processes for chemically prepared zinc oxide varistors.

    Energy Technology Data Exchange (ETDEWEB)

    Lockwood, Steven John; Voigt, James A.; Tuttle, Bruce Andrew; Bell, Nelson Simmons

    2005-01-01

    Chemically prepared zinc oxide powders are fabricated for the production of high aspect ratio varistor components. Colloidal processing in water was performed to reduce agglomerates to primary particles, form a high solids loading slurry, and prevent dopant migration. The milled and dispersed powder exhibited a viscoelastic to elastic behavioral transition at a volume loading of 43-46%. The origin of this transition was studied using acoustic spectroscopy, zeta potential measurements and oscillatory rheology. The phenomenon occurs due to a volume fraction solids dependent reduction in the zeta potential of the solid phase. It is postulated to result from divalent ion binding within the polyelectrolyte dispersant chain, and was mitigated using a polyethylene glycol plasticizing additive. Chemically prepared zinc oxide powders were processed for the production of high aspect ratio varistor components. Near net shape casting methods including slip casting and agarose gelcasting were evaluated for effectiveness in achieving a uniform green microstructure achieving density values near the theoretical maximum during sintering. The structure of the green parts was examined by mercury porisimetry. Agarose gelcasting produced green parts with low solids loading values and did not achieve high fired density. Isopressing the agarose cast parts after drying raised the fired density to greater than 95%, but the parts exhibited catastrophic shorting during electrical testing. Slip casting produced high green density parts, which exhibited high fired density values. The electrical characteristics of slip cast parts are comparable with dry pressed powder compacts. Alternative methods for near net shape forming of ceramic dispersions were investigated for use with the chemically prepared ZnO material. Recommendations for further investigation to achieve a viable production process are presented.

  14. Forming technologies for manufacturing and processing of lightweight structures; Umformverfahren zur Herstellung und Weiterverarbeitung von Leichtbaustrukturen

    Energy Technology Data Exchange (ETDEWEB)

    Kopp, R.; Ebert, A.; Hohmeier, P.; Schulz, J. [Technische Hochschule Aachen (Germany). Inst. fuer Bildsame Formgebung

    2000-07-01

    Besides Air- and Space-technology, a growing demand for lightweight structures has developed during the last years in fields such as car manufacture. This paper presents the activities in the field of lightweight construction carried out at the Institute of Metal forming of Aachen University of Technology. Examples for developed lightweight structures are Tailor Rolled Blanks and Grid Sheets. In both cases the potential for weight reduction as well as formability is pointed out. Furthermore the Shot Peen Forming process is presented which enables the production of large spacecraft parts with three-dimensional curvatures. By means of two sided peening this process can be optimised regarding part properties and productivity. First results of Finite-Element Simulations of the two sided process are presented. (orig.) [German] In den vergangenen Jahren hat die Entwicklung und der Einsatz von Leichtbaustrukturen in der Automobilindustrie zunehmend an Bedeutung gewonnen und gehoert heute ohne Zweifel zu einem der Forschungsschwerpunkte in dieser Branche. Besondere Impulse entstanden durch die Selbstverpflichtung der Automobilindustrie, die CO{sub 2} Emissionen neu zugelassener Fahrzeuge von heute 186 g/km bis zum Jahre 2008 auf 140 g/km zu reduzieren. Neben der Automobilindustrie gewinnt der Leichtbau aber auch in anderen Branchen an 'Gewicht'. Beispielhaft sei hier der Maschinenbau genannt, wo das Bestreben zu einer Reduktion der Nebenzeiten zu immer hoeheren Verfahrgeschwindigkeiten der Werkzeuge fuehrt. Hierdurch werden die mit den Beschleunigungen verbundenen Massenkraefte immer oefter groesser als die eigentlichen Prozesskraefte. Eine Reduzierung von Beschleunigungskraeften bei gleichzeitiger Verbesserung der Dynamik erfordert eine Reduzierung der Massen und damit Leichtbau. Anhand ausgewaehlter Beispiele sollen im Folgenden die Taetigkeiten des Instituts fuer Bildsame Formgebung (IBF) auf dem Gebiet der Leichtbauforschung und -entwicklung dargestellt und

  15. Efficient Robust Optimization of Metal Forming Processes using a Sequential Metamodel Based Strategy

    Science.gov (United States)

    Wiebenga, J. H.; Klaseboer, G.; van den Boogaard, A. H.

    2011-08-01

    The coupling of Finite Element (FE) simulations to mathematical optimization techniques has contributed significantly to product improvements and cost reductions in the metal forming industries. The next challenge is to bridge the gap between deterministic optimization techniques and the industrial need for robustness. This paper introduces a new and generally applicable structured methodology for modeling and solving robust optimization problems. Stochastic design variables or noise variables are taken into account explicitly in the optimization procedure. The metamodel-based strategy is combined with a sequential improvement algorithm to efficiently increase the accuracy of the objective function prediction. This is only done at regions of interest containing the optimal robust design. Application of the methodology to an industrial V-bending process resulted in valuable process insights and an improved robust process design. Moreover, a significant improvement of the robustness (>2σ) was obtained by minimizing the deteriorating effects of several noise variables. The robust optimization results demonstrate the general applicability of the robust optimization strategy and underline the importance of including uncertainty and robustness explicitly in the numerical optimization procedure.

  16. Residual stress evaluation and curvature behavior of aluminum 7050 peen forming processed

    International Nuclear Information System (INIS)

    Shot peening is a superficial cold work process used to increase the fatigue life evaluated by residual stress measurements. The peen forming process is a variant of the shot peening process, where a curvature in the plate is obtained by the compression of the grains near to the surface. In this paper, the influence of the parameters such as: pressure of shot, ball shot size and thickness of aluminum 7050 samples with respect to residual stress profile and resulting arc height was studied. The evaluation of the residual stress profile was obtained by sin2 ψ method. The results show that the formation of the curvature arc height is proportional to the shot peening pressure, of spheres size and inversely proportional to the thickness of the sample, and that stress concentration factor is larger for samples shot peened with small balls. On final of this paper presents an additional study on micro strain and average crystallite size, which can evaluate the profile of the samples after blasting. (author)

  17. 10 CFR 140.107 - Appendix G-Form of indemnity agreement with licensees processing plutonium for use in plutonium...

    Science.gov (United States)

    2010-01-01

    ... processing plutonium for use in plutonium processing and fuel fabrication plants and furnishing insurance... § 140.107 Appendix G—Form of indemnity agreement with licensees processing plutonium for use in plutonium processing and fuel fabrication plants and furnishing insurance policies as proof of...

  18. Sorption of diuron, atrazine, and copper ion on chars with long-term natural oxidation in soils

    Science.gov (United States)

    Cheng, C.; Lin, T.; Lai, C.

    2011-12-01

    Biochar has been proposed as a measure to sequestrate carbon (C) and to increase soil fertility in sustainable agriculture. However, its sorption characteristics to herbicides, such as lowing herbicides efficacy, may constrain its agricultural application. This assertion may be arguable because most studies so far were conducted with the newly produced char and barely considered the "ageing effect" of old char since it could be oxidized over long time. In this study, historical char samples were collected and compared with the newly produced char. Batch sorption studies of diuron, atrazine, and copper ion onto chars was performed. Greater sorption of Cu was observed on the historical char samples and reached a saturated sorption at 30 mg g-1 for Cu, much higher adsorption value than newly produced char at 4 mg g-1. In contrast, sorption of diuron and atrazine on newly produced char had the highest sorption capacity than the historical char samples. The historical chars also had much higher negative charge than the newly produced char, but its surface area were lower than the new char. The results indicated that change in surface functional groups through natural oxidation rather than the change of surface area may have more pronounced influences on sorption characteristics, in which the negative charge on the historical chars' surface could hinder the adsorption of diuron and atrazine while enhance the sorption to copper ion. Biological assay to test the toxicity of diuron and copper ion for both historical and new chars on rye seed were conducted and will be presented in our poster.

  19. A first step towards identification of tannin-derived black carbon: Conventional pyrolysis (Py–GC–MS) and thermally assisted hydrolysis and methylation (THM–GC–MS) of charred condensed tannins

    NARCIS (Netherlands)

    Kaal, J.; Nierop, K.G.J.; Kraal, P.; Preston, C.M.

    2012-01-01

    Tannins account for a significant proportion of plant biomass and are likely to contribute to the residues formed by incomplete biomass combustion (black carbon, BC). Nonetheless, the molecular properties of thermally modified tannins have not been investigated in laboratory charring experiments. We

  20. FUNCTIONAL AND METABOLIC FEATURES OF BLOOD PHAGOCYTES AT DIFFERENT FORMS OF TUBERCULAR INFLAMMATORY PROCESS OF LUNGS

    Directory of Open Access Journals (Sweden)

    O. V. Berdyugina

    2016-01-01

    Full Text Available A leading role of phagocytes in prevention of M. tuberculosis infection is well established. Various clinical variants of tubercular inflammatory process necessitate further studies of functional and metabolic features of blood phagocytes in the patients with different forms of lung tuberculosis, being the main goal of this study. We have observed a total of 124 persons including 25 healthy subjects, and 99 patients with tuberculosis who manifested with different types of tubercular inflammatory process, i.e., 31 patients had a limited specific process (tuberculoma; in 44 patients, an infiltrative lung tuberculosis was diagnosed, and 24 patients had fibro-cavernous tuberculosis of lungs. We studied activation markers of neutrophils and monocytes (phagotest, burst-test, CD11b+, CD11c+, HLA-DR-Ag, as well as main indicators of cellular immunity (CD45+CD3+, CD45+CD19+, CD45+CD3- CD16+56+. Statistical evaluation was carried out in the «Microsoft Office Excel 2007» and «Statistica for Windows v. 6.1» environment.A considerable decrease in proportion of superoxide anion-producing monocytes was found in 10% of the patients with fibro-cavernous tuberculosis as compared to the patients with tuberculoma and infiltrative tuberculosis. Similarly, the fibro-cavernous tuberculosis was characterized by higher expression of adhesion markers, e.g., CD11b, by 49%, and CD11c, by 73.5%, when compared with the two other groups of patients. A considerable decrease of absorbing granulocyte function was found in the patients with active forms of tuberculosis, as compared with limited clinical forms (tuberculoma. Fibro-cavernous tuberculosis was associated with increased absolute numbers of granulocyte that produce both superoxide anion, and express surface CD11b+ and CD11c+. We have revealed a relative decrease in lymphocyte quantities in the patients from tuberculoma which corresponded to increased granulocyte quantities of granulocytes and monocytes in the

  1. Potential of aeration flow rate and bio-char addition to reduce greenhouse gas and ammonia emissions during manure composting.

    Science.gov (United States)

    Chowdhury, Md Albarune; de Neergaard, Andreas; Jensen, Lars Stoumann

    2014-02-01

    Aeration is an important factor influencing CO2, CH4, N2O and NH3 emissions from the composting process. Both CH4 and N2O are potent greenhouse gases (GHG) of high importance. Here, we examined the effects of high and low aeration rates together with addition of barley straw with and without bio-char on GHG and NH3 emissions from composting cattle slurry and hen manure in small-scale laboratory composters. Depending on treatment, cumulative C losses via CO2 and CH4 emissions accounted for 11.4-22.5% and 0.004-0.2% of initial total carbon, while N losses as N2O and NH3 emissions comprised 0.05-0.1% and 0.8-26.5% of initial total nitrogen, respectively. Decreasing the flow rate reduced cumulative NH3 losses non-significantly (by 88%) but significantly increased CH4 losses (by 51%) from composting of cattle slurry with barley straw. Among the hen manure treatments evaluated, bio-char addition to composting hen manure and barley straw at low flow rates proved most effective in reducing cumulative NH3 and CH4 losses. Addition of bio-char in combination with barley straw to hen manure at both high and low flow rates reduced total GHG emissions (as CO2-equivalents) by 27-32% compared with barley straw addition alone. Comparisons of flow rates showed that low flow could be an alternative strategy for reducing NH3 losses without any significant change in N2O emissions, pointing to the need for well-controlled composting conditions if gaseous emissions are to be minimised.

  2. FORMING OF THE PERSONALITY OF SAFE TYPE IN THE PROCESS OF PEDAGOGICAL EDUCATION

    Directory of Open Access Journals (Sweden)

    Margarita Viktorovna Pogodaeva

    2014-08-01

    Full Text Available During of the preparing for teaching activities necessary to generate creative activities  in teachers, willingness to overcome difficulties, dangerous and unexpected situations. In article regarded the problem optimization of teaching and educational processIn directional on formation personality of safety type This training of each student to a self-appraisal and introspection of behavioral risks , working out and realization of the individual program of health, integration of disciplines safety  with other disciplines of the curriculum forming of teacher’s personal qualities  on basis moral values,  creativity.  Measure of the quality of profession preparing of the future teacher becomes the presence of his personal qualities, allowing to implement ideas in teaching practice safe life and safe interaction with all the elements of the world.

  3. Forming impressions of people versus inanimate objects: social-cognitive processing in the medial prefrontal cortex.

    Science.gov (United States)

    Mitchell, Jason P; Neil Macrae, C; Banaji, Mahzarin R

    2005-05-15

    Recent neuroimaging research has linked the task of forming a "person impression" to a distinct pattern of neural activation that includes dorsal regions of the medial prefrontal cortex (mPFC). Although this result suggests the distinctiveness of social cognition - the processes that support inferences about the psychological aspects of other people - it remains unclear whether mPFC contributions to this impression formation task were person specific or if they would extend to other stimulus targets. To address this unresolved issue, participants in the current study underwent fMRI scanning while performing impression formation or a control task for two types of target: other people and inanimate objects. Specifically, participants were asked to use experimentally-provided information either to form an impression of a person or an object or to intentionally encode the sequence in which the information was presented. Results demonstrated that activation in an extensive region of dorsal mPFC was greater for impression formation of other people than for all other trial types, suggesting that this region specifically indexes the social-cognitive aspects of impression formation (i.e., understanding the psychological characteristics of another mental agent). These findings underscore the extent to which social cognition relies on distinct neural mechanisms.

  4. Forming impressions of people versus inanimate objects: social-cognitive processing in the medial prefrontal cortex.

    Science.gov (United States)

    Mitchell, Jason P; Neil Macrae, C; Banaji, Mahzarin R

    2005-05-15

    Recent neuroimaging research has linked the task of forming a "person impression" to a distinct pattern of neural activation that includes dorsal regions of the medial prefrontal cortex (mPFC). Although this result suggests the distinctiveness of social cognition - the processes that support inferences about the psychological aspects of other people - it remains unclear whether mPFC contributions to this impression formation task were person specific or if they would extend to other stimulus targets. To address this unresolved issue, participants in the current study underwent fMRI scanning while performing impression formation or a control task for two types of target: other people and inanimate objects. Specifically, participants were asked to use experimentally-provided information either to form an impression of a person or an object or to intentionally encode the sequence in which the information was presented. Results demonstrated that activation in an extensive region of dorsal mPFC was greater for impression formation of other people than for all other trial types, suggesting that this region specifically indexes the social-cognitive aspects of impression formation (i.e., understanding the psychological characteristics of another mental agent). These findings underscore the extent to which social cognition relies on distinct neural mechanisms. PMID:15862225

  5. Residual stress evaluation and curvature behavior of aluminium 7050 peen forming processed; Avaliacao da tensao residual em aluminio 7050 conformado pelo processo peen forming

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, R.R. de; Lima, N.B., E-mail: rolivier@ipen.b, E-mail: nblima@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Braga, A.P.V.; Goncalves, M., E-mail: anapaola@ipt.b, E-mail: mgoncalves@ipt.b [Instituto de Pesquisas Tecnologicas (IPT), Sao Paulo, SP (Brazil)

    2010-07-01

    Shot peening is a superficial cold work process used to increase the fatigue life evaluated by residual stress measurements. The peen forming process is a variant of the shot peening process, where a curvature in the plate is obtained by the compression of the grains near to the surface. In this paper, the influence of the parameters such as: pressure of shot, ball shot size and thickness of aluminum 7050 samples with respect to residual stress profile and resulting arc height was studied. The evaluation of the residual stress profile was obtained by sin{sup 2} {Psi} method. (author)

  6. FY16 Annual Accomplishments - Waste Form Development and Performance: Evaluation Of Ceramic Waste Forms - Comparison Of Hot Isostatic Pressed And Melt Processed Fabrication Methods

    Energy Technology Data Exchange (ETDEWEB)

    Amoroso, J. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Dandeneau, C. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-10-13

    FY16 efforts were focused on direct comparison of multi-phase ceramic waste forms produced via melt processing and HIP methods. Based on promising waste form compositions previously devised at SRNL[13], simulant material was prepared at SRNL and a portion was sent to the Australian Nuclear Science and Technology Organization (ANSTO) for HIP treatments, while the remainder of the material was melt processed at SRNL. The microstructure, phase formation, elemental speciation, and leach behavior, and radiation stability of the fabricated ceramics was performed. In addition, melt-processed ceramics designed with different fractions of hollandite, zirconolite, perovskite, and pyrochlore phases were investigated. for performance and properties. Table 1 lists the samples studied.

  7. Prediction of the burnout behaviour of chars derived from coal-biomass blends

    Energy Technology Data Exchange (ETDEWEB)

    Tao Wu; Mei Gong; Edward Lester [University of Nottingham, Nottingham (United Kingdom). School of Chemical, Environmental and Mining Engineering

    2007-07-01

    Nowadays, biomass has been considered an alternative fuel to coal and is being used in power plants to replace part of coal used. This study is to investigate the potential of burning biomass with coal and its impacts on burnout levels. Daw Mill coal was selected for burnout modelling together with three biomasses, Cereal, PKE and Olive Cake. Chars were prepared (75-106 micron) and characterised using image analysis methods as in input data into the char burnout model (ChB) which was adapted to allow the prediction of char burnout of biomass-coal blends under typical pf combustion conditions. The burnout performance of four blend compositions for each biomass were modelled (5%, 10%, 20% and 30%). In practice, the low heating-value of biomass produces a lower flame temperature which can lead to lower levels of char burn-out. The effect is closely linked with the type of biomass used. 36 refs., 4 figs., 1 tab.

  8. The different effects of applying fresh, composted or charred manure on soil N2O emissions

    DEFF Research Database (Denmark)

    Zhu, Kun; Christel, Wibke; Bruun, Sander;

    2014-01-01

    New manure management strategies and technologies are currently being developed in order to reduce manure volume and odorous emissions, utilise energy potential and produce improved manure-derived fertilisers. This has accentuated the need to determine their effects on greenhouse gas emissions...... to higher N2O and CO2 emissions than heterogeneous distribution. However, the effect of different distribution modes was not significant in treatments with charred manure, since N turnover in the immature compost was much more active than that in the charred manure. By combining charred manure...... with composted manure, N2O emissions were significantly reduced by 41% at pF 2.0, but the mitigation effect of charred manure was not observed at lower soil water potentials. © 2014 Elsevier Ltd....

  9. STRUCTURE-BASED PREDICTIVE MODEL FOR COAL CHAR COMBUSTION

    Energy Technology Data Exchange (ETDEWEB)

    CHRISTOPHER M. HADAD; JOSEPH M. CALO; ROBERT H. ESSENHIGH; ROBERT H. HURT

    1998-06-04

    During the past quarter of this project, significant progress continued was made on both major technical tasks. Progress was made at OSU on advancing the application of computational chemistry to oxidative attack on model polyaromatic hydrocarbons (PAHs) and graphitic structures. This work is directed at the application of quantitative ab initio molecular orbital theory to address the decomposition products and mechanisms of coal char reactivity. Previously, it was shown that the �hybrid� B3LYP method can be used to provide quantitative information concerning the stability of the corresponding radicals that arise by hydrogen atom abstraction from monocyclic aromatic rings. In the most recent quarter, these approaches have been extended to larger carbocyclic ring systems, such as coronene, in order to compare the properties of a large carbonaceous PAH to that of the smaller, monocyclic aromatic systems. It was concluded that, at least for bond dissociation energy considerations, the properties of the large PAHs can be modeled reasonably well by smaller systems. In addition to the preceding work, investigations were initiated on the interaction of selected radicals in the �radical pool� with the different types of aromatic structures. In particular, the different pathways for addition vs. abstraction to benzene and furan by H and OH radicals were examined. Thus far, the addition channel appears to be significantly favored over abstraction on both kinetic and thermochemical grounds. Experimental work at Brown University in support of the development of predictive structural models of coal char combustion was focused on elucidating the role of coal mineral matter impurities on reactivity. An �inverse� approach was used where a carbon material was doped with coal mineral matter. The carbon material was derived from a high carbon content fly ash (Fly Ash 23 from the Salem Basin Power Plant. The ash was obtained from Pittsburgh #8 coal (PSOC 1451). Doped

  10. Control of sheet-metal forming processes with piezoactuators in smart structures

    Science.gov (United States)

    Neugebauer, Reimund; Hoffmann, Michael; Roscher, Hans-Jürgen; Scheffler, Sören; Wolf, Klaus

    2006-03-01

    The most important project in sheet metal forming is streamlining the material flow since each rejects increases production costs. Using the multipoint cushion device together with an elastic blankholder makes it possible to actively manipulate the material flow in the flange range. This allows major enhancements in the deformation ratio, especially with the novel high strength materials in car body production. State-of-the-art is multiple draw pins to initiate the force on selected points on the blankholder. Admittedly, the cushion plate does not allow optimum force allocation because it is situated between hydraulic pressure rollers and draw pins. Replacing selected draw pins with piezoactuators for generating high forces allows systematic control of the force progression at critical forming areas during sheet draw-in. The system, consisting of the piezostack actuator, dynamometer and components for force initiation, was built as a compact unit with low resilience with the intension of using the inherent sensory properties of the piezostack actuator to measure force. Applying this principle throughout allows a reduction of hydraulic components which eventually lead to a less expensive one- point cushion device. Initial finding have already been arrived at in the context of a research project at the Fraunhofer Institute for Machine Tools and Forming Technology in Chemnitz, Germany in cooperation with a partner from the automobile industry. A draw pin was replaced ad hoc with a highly durable piezoactuator integrated in a force control cycle. The force progression during the sheet draw-in could be accurately adjusted according to a predetermined master curve. The master curve was taken up in the unregulated process and represents the quality criteria of a formed useable part. The real-time MATLAB Simulink XPC- Target simulation tool was used to develop an adjustment strategy that connects the specific signals of the press control (such as the tappet path, the die

  11. Desert Pavement Process and Form: Modes and Scales of Landscape Stability and Instability in Arid Regions

    Science.gov (United States)

    Wells, Stephen G.; McFadden, Leslie D.; McDonald, Eric V.; Eppes, Martha C.; Young, Michael H.; Wood, Yvonne A.

    2014-05-01

    Desert pavements are recognized in arid landscapes around the world, developing via diminution of constructional/depositional landform relief and creating a 1-2 stone thick armor over a "stone free" layer. Surface exposure dating demonstrates that clasts forming the desert pavements are maintained at the land surface over hundreds of thousands of years, as aeolian fines are deposited on the land surface, transported into the underlying parent material and incorporated into accretionary soil horizons (e.g., the stone free or vesicular [Av] horizon). This surface armor provides long-term stability over extensive regions of the landscape. Over shorter time periods and at the landform-element scale, dynamic surficial processes (i.e., weathering, runoff) continue to modify the pavement form. Clast size reduction in comparison to underlying parent material, along with armoring and packing of clasts in pavements contribute to their persistence, and studies of crack orientations in pavement clasts indicate physical weathering and diminution of particle size are driven by diurnal solar insolation. Over geologic time, cracks form and propagate from tensile stresses related to temporal and spatial gradients in temperature that evolve and rotate in alignment with the sun's rays. Observed multimodal nature of crack orientations appear related to seasonally varying, latitude-dependent temperature fields resulting from solar angle and weather conditions. Surface properties and their underlying soil profiles vary across pavement surfaces, forming a landscape mosaic and controlling surface hydrology, ecosystem function and the ultimate life-cycle of arid landscapes. In areas of well-developed pavements, surface infiltration and soluble salt concentrations indicate that saturated hydraulic conductivity of Av horizons decline on progressively older alluvial fan surfaces. Field observations and measurements from well-developed desert pavement surfaces landforms also yield

  12. On-line measurements to control the forming process of glass vials

    Science.gov (United States)

    Angrilli, Francesco; Bianchini, Gianandrea; Fanti, Giulio; Mozzi, Massimo

    1993-02-01

    The most relevant parameters to control the quality of glass vials are the internal and external diameters of the mouth and the height of the rim. A low cost vision system based on a 486 PC, a frame grabber, 4 CCD cameras (768 X 512 pixels) and I/O device to control the production of vials, by adjusting the flames temperature in the moulding section of the machine, has been developed and tested. A 24 mandrel machine rotating at about 300 rpm with a production capability of about 4200 pieces/hour had to be monitored with an accuracy of +/- 0.02 mm in the measure of the mouth diameters and +/- 0.04 mm on the rim height. In order to minimize the time delay required for the machine temperature compensation, the measurements had to be taken during the forming process. The system must be fast enough to follow the process, able to take into account the temperature variation of different classes of vials and far enough from the high temperature of the flames. A direct calibration procedure, using a reference vial, and a pyrometer to check the temperature range was derived. A long focus lens coupled with a bellow to put the system away from the flames was adopted. The algorithm implemented for the measurements and the machine temperature control is presented.

  13. Forming a filter media from zeolite modified with SDBAC for wastewater treatment process

    Directory of Open Access Journals (Sweden)

    Kolaković Srđan

    2014-01-01

    Full Text Available This paper investigates the effects of several parameters (amounts of organic matter, grain size, content of solid phase, stirring rate, and temperature on the adsorption of stearyl dimethyl benzyl ammonium chloride (SDBAC in natural zeolite tuff in the process of formation of adsorbents based on organo-zeolite, a potential filter in waste water treatment process. Obtained results show that the most favorable ratio between the amount of SDBAC and zeolites is 50-75 mmol M+/kg. Larger grains have lower zeolite adsorption power of organic cations on the surface of zeolite, while favorable percentage of content of solids in the zeolite suspension is 10-20%. Interference between adsorption of mixture and temperature, especially in volumes of SDBAC lower than 75 mmol M+/kg of zeolite, have no significant impact on adsorption of organic cations on the surface of the zeolite. The obtained results present an initial step for defining the optimal operating parameters for forming adsorbents based on organo-zeolite as a filter potentially utilized in waste water treatment. [Projekat Ministarstva nauke Republike Srbije, br. TR 37018 i br. TR 37003

  14. Effect of extrusion wheel angular velocity on continuous extrusion forming process of copper concave bus bar

    Institute of Scientific and Technical Information of China (English)

    WU Peng-yue; XIE Shui-sheng; LI Hua-qing; YAN Ming; HUANG Guo-jie; CHENG Lei

    2007-01-01

    The continuous extrusion forming process for producing large section copper concave bus bar under different extrusion wheel angular velocities was studied by three-dimensional finite element technology based on software DEFORM-3D. The rigid-viscoplastic constitutive equation was employed in the model. The numerical simulation results show that the deformation body flow velocity in the die orifice increases gradually with the increase of the extrusion wheel angular velocity. But slippage between the rod and extrusion wheel occurs when the extrusion wheel angular velocity is high. The effective stress near the die orifice enhances gradually with increasing extrusion wheel angular velocity. High stress is concentrated in adjacent regions of the flash gap. The effective strain gradient is greater near the abutment than that near the die orifice. The effective strain of the product increases gradually with increasing extrusion wheel angular velocity. In the deformation process, the deformation body temperature increases remarkably due to friction and deformation. So the cooling is necessary in the region of the die and tools.

  15. Development of coconut pith chars towards high elemental mercury adsorption performance - Effect of pyrolysis temperatures.

    Science.gov (United States)

    Johari, Khairiraihanna; Saman, Norasikin; Song, Shiow Tien; Cheu, Siew Chin; Kong, Helen; Mat, Hanapi

    2016-08-01

    In this study, chars from coconut pith (CP) were prepared aiming for superior adsorption towards elemental mercury (Hg(o)). The yield, proximate analysis, textural characteristics, surface functional groups and elemental composition analyses of the chars produced at pyrolysis temperature of 300 °C, 500 °C, 700 °C and 900 °C were compared. The surface area, pore volume, ash and carbon content of chars increased, while the yield and moisture content decreased with increasing pyrolysis temperatures. The changing of physical and chemical properties of the chars produced at variety pyrolysis temperature was much effect on the Hg(o) adsorption performance and definitely provides important information on the Hg(o) adsorption mechanism. The highest Hg(o) adsorption capacity was observed for CP900 (6067.49 μg/g), followed by CP700 (2395.98 μg/g), CP500 (289.76 μg/g), CP300 (1.68 μg/g), and CP (0.73 μg/g). The equilibrium data were well described by the Freundlich adsorption isotherm model. The pseudo-second order best described the kinetic data of the Hg(o) adsorption onto CP and CP300. For chars produced at higher pyrolysis temperature, however, the pseudo-zero order and pseudo-second order fitted well for the adsorption and breakthrough regions, respectively. The Hg(o) adsorption capacity of chars obtained from high pyrolysis temperature of CP significantly outperformed the commercial activated carbon (Darco KB-B) as well as superior to chars reported in the literature indicating the CP can be used as a precursor for preparation of chars as elemental mercury adsorbents. PMID:27160635

  16. Development of coconut pith chars towards high elemental mercury adsorption performance - Effect of pyrolysis temperatures.

    Science.gov (United States)

    Johari, Khairiraihanna; Saman, Norasikin; Song, Shiow Tien; Cheu, Siew Chin; Kong, Helen; Mat, Hanapi

    2016-08-01

    In this study, chars from coconut pith (CP) were prepared aiming for superior adsorption towards elemental mercury (Hg(o)). The yield, proximate analysis, textural characteristics, surface functional groups and elemental composition analyses of the chars produced at pyrolysis temperature of 300 °C, 500 °C, 700 °C and 900 °C were compared. The surface area, pore volume, ash and carbon content of chars increased, while the yield and moisture content decreased with increasing pyrolysis temperatures. The changing of physical and chemical properties of the chars produced at variety pyrolysis temperature was much effect on the Hg(o) adsorption performance and definitely provides important information on the Hg(o) adsorption mechanism. The highest Hg(o) adsorption capacity was observed for CP900 (6067.49 μg/g), followed by CP700 (2395.98 μg/g), CP500 (289.76 μg/g), CP300 (1.68 μg/g), and CP (0.73 μg/g). The equilibrium data were well described by the Freundlich adsorption isotherm model. The pseudo-second order best described the kinetic data of the Hg(o) adsorption onto CP and CP300. For chars produced at higher pyrolysis temperature, however, the pseudo-zero order and pseudo-second order fitted well for the adsorption and breakthrough regions, respectively. The Hg(o) adsorption capacity of chars obtained from high pyrolysis temperature of CP significantly outperformed the commercial activated carbon (Darco KB-B) as well as superior to chars reported in the literature indicating the CP can be used as a precursor for preparation of chars as elemental mercury adsorbents.

  17. Leaching behaviour and ecotoxicity evaluation of chars from the pyrolysis of forestry biomass and polymeric materials

    OpenAIRE

    Bernardo, Maria S.; Mendes, S.; Lapa, N.; Gonçalves, Margarida; Mendes, Benilde; Pinto, Filomena; Lopes, M. Helena

    2014-01-01

    The main objective of this study was to assess the environmental risk of chars derived from the pyrolysis of mixtures of pine, plastics, and scrap tires, by studying their leaching potential and ecotoxicity. Relationships between chemical composition and ecotoxicity were established to identify contaminants responsible for toxicity. Since metallic contaminants were the focus of the present study, an EDTA washing step was applied to the chars to selectively remove metals that can be responsibl...

  18. Fluoride removal from drinking water by adsorption using bone char as a biosorbent

    OpenAIRE

    Ma, W; Ya, F.; Wang, R.; Zhao, Y. Q.

    2008-01-01

    As a biomass material, bone char was investigated for the feasibility to be used as a cost-effective biosorbent for fluoride removal from drinking water in groundwater environment. Based on the batch tests with natural tourmalin and active alumina being the reference adsorbents, BF (referring to bone char) has demonstrated a higher fluoride adsorption capacity. This capacity was found being increased with the increase of fluoride concentration. Furthermore, BF based column adsorption experime...

  19. A Risk-Based Strategy for Evaluating Mitigation Options for Process-Formed Compounds in Food: Workshop Proceedings.

    Science.gov (United States)

    Hanlon, Paul; Brorby, Gregory P; Krishan, Mansi

    2016-05-01

    Processing (eg, cooking, grinding, drying) has changed the composition of food throughout the course of human history; however, awareness of process-formed compounds, and the potential need to mitigate exposure to those compounds, is a relatively recent phenomenon. In May 2015, the North American Branch of the International Life Sciences Institute (ILSI North America) Technical Committee on Food and Chemical Safety held a workshop on the risk-based process for mitigation of process-formed compounds. This workshop aimed to gain alignment from academia, government, and industry on a risk-based process for proactively assessing the need for and benefit of mitigation of process-formed compounds, including criteria to objectively assess the impact of mitigation as well as research needed to support this process. Workshop participants provided real-time feedback on a draft framework in the form of a decision tree developed by the ILSI North America Technical Committee on Food and Chemical Safety to a panel of experts, and they discussed the importance of communicating the value of such a process to the larger scientific community and, ultimately, the public. The outcome of the workshop was a decision tree that can be used by the scientific community and could form the basis of a global approach to assessing the risks associated with mitigation of process-formed compounds. PMID:27102178

  20. About Distributed Simulation-based Optimization of Forming Processes using a Grid Architecture

    Science.gov (United States)

    Grauer, Manfred; Barth, Thomas

    2004-06-01

    Permanently increasing complexity of products and their manufacturing processes combined with a shorter "time-to-market" leads to more and more use of simulation and optimization software systems for product design. Finding a "good" design of a product implies the solution of computationally expensive optimization problems based on the results of simulation. Due to the computational load caused by the solution of these problems, the requirements on the Information&Telecommunication (IT) infrastructure of an enterprise or research facility are shifting from stand-alone resources towards the integration of software and hardware resources in a distributed environment for high-performance computing. Resources can either comprise software systems, hardware systems, or communication networks. An appropriate IT-infrastructure must provide the means to integrate all these resources and enable their use even across a network to cope with requirements from geographically distributed scenarios, e.g. in computational engineering and/or collaborative engineering. Integrating expert's knowledge into the optimization process is inevitable in order to reduce the complexity caused by the number of design variables and the high dimensionality of the design space. Hence, utilization of knowledge-based systems must be supported by providing data management facilities as a basis for knowledge extraction from product data. In this paper, the focus is put on a distributed problem solving environment (PSE) capable of providing access to a variety of necessary resources and services. A distributed approach integrating simulation and optimization on a network of workstations and cluster systems is presented. For geometry generation the CAD-system CATIA is used which is coupled with the FEM-simulation system INDEED for simulation of sheet-metal forming processes and the problem solving environment OpTiX for distributed optimization.

  1. Effect of cation exchange on the subsequent reactivity of lignite chars to steam. [108 references

    Energy Technology Data Exchange (ETDEWEB)

    Hippo, E. J.; Walker, Jr., P. L.

    1977-03-01

    The purpose of this investigation is to determine the role which cations in coal play in the subsequent reactivity of chars. It is hoped that this investigation will aid in an understanding of the catalytic nature of inorganic constituents in coal during its gasification. It was found that increased heat treatment temperature decreased reactivity. The decrease in reactivity was shown to be due, at least in part, to the changes in the nature of the cation with increased heat treatment temperature. Reactivity was found to be a linear function of the amount of Ca(++) exchange on the demineralized coal. The constant utilization factor over the wide range of loadings employed indicated that below 800/sup 0/C the calcium did not markedly sinter. Potassium, sodium, and calcium-containing chars were found to be much more reactive than the iron and magnesium-containing chars. However, the iron and magnesium containing chars were more reactive than chars produced from the demineralized coal. The iron char was highly active at first but the iron phase was quickly oxidized to a comparatively unreactive ..gamma..Fe/sub 2/O/sub 3/-Fe/sub 3/O/sub 4/ phase. The state of magnesium was found to be MgO. Sodium and calcium were equally active as catalysts but not as active as potassium.

  2. Improvement of biomass char-CO{sub 2} gasification reactivity using microwave irradiation and natural catalyst

    Energy Technology Data Exchange (ETDEWEB)

    Lahijani, Pooya, E-mail: pooya.lahijani@gmail.com [Biomass and Bioenergy Laboratory, School of Mechanical Engineering, Universiti Sains Malaysia, 14300 Nibong Tebal, Pulau Pinang (Malaysia); Mohammadi, Maedeh, E-mail: m.mohammadi@nit.ac.ir [Faculty of Chemical Engineering, Babol Noushirvani University of Technology, 47148 Babol (Iran, Islamic Republic of); Zainal, Zainal Alimuddin, E-mail: mezainal@eng.usm.my [Biomass and Bioenergy Laboratory, School of Mechanical Engineering, Universiti Sains Malaysia, 14300 Nibong Tebal, Pulau Pinang (Malaysia); Mohamed, Abdul Rahman, E-mail: chrahman@usm.my [Low Carbon Economy (LCE) Research Group, School of Chemical Engineering, Engineering Campus, Universiti Sains Malaysia, 14300 Nibong Tebal, Pulau Pinang (Malaysia)

    2015-03-20

    Highlights: • We study microwave-induced gasification of EFB ash-loaded biomass char with CO{sub 2}. • Synergistic effect of microwave and catalyst resulted in CO{sub 2} conversion of 93%. • Gasification of pristine char using conventional heating gives CO{sub 2} conversion of 58%. • E{sub a} of 74 and 247 kJ/mol were obtained for microwave and conventional CO{sub 2} gasification. - Abstract: In char-CO{sub 2} gasification, the highly endothermic nature of the Boudouard reaction (CO{sub 2} (g) + C (s) ↔ 2CO (g)) dictates use of very high temperatures to shift the equilibrium towards CO production. In this study, such high temperature (750–900 °C) was provided by microwave irradiation. A microwave heating system was developed to perform the gasification tests by passing CO{sub 2} through a packed bed of oil palm shell (OPS) char. In order to speed up the microwave-induced CO{sub 2} gasification, ash of palm empty fruit bunch (EFB) was used as natural catalyst (rich in potassium) and incorporated into the skeleton of the OPS char. The synergistic effect of microwave and catalyst concluded to very encouraging results, where a CO{sub 2} conversion of 93% was achieved at 900 °C, within 60 min microwave gasification. In comparison, CO{sub 2} conversion in thermal gasification (conventional heating) of pristine OPS char was only 58% under the same operating condition.

  3. Effects of Charred Fructus Crataegi on the contractilily of isolated rat gastric and intestine muscle strips

    Institute of Scientific and Technical Information of China (English)

    ZHANG Hou-li; DIAO Yun-peng; LIU Zhi-hao; HUANG Shan-shan; MA Xiao-chi; LIN Yuan

    2008-01-01

    Objective The purpose of the study is to investigate the effects of Charred Fructus Crataegi Alcohol Extract on contractililty of isolated rat gastric and intesting smooth muscle strips. Methods Isolated rat intestine was selected in the assay to test the effects of Charred Fructus Crataegi Alcohol Extract on contractilty of isolated rat gastric and intestine smooth muscle strips using Krebs' solution, to observe the effects of in the presence of acetylcholine or atropine. Results Charred Fructus Crataegi Alcohol Extract in the range of 2-8 rag crude drugs/mL could significantly reduce the contractility of rat gastric and intestine smooth muscle strips in a dose-dependent manner, and Charred Fructus Crataegi Alcohol Extract 8 mg·mL-1(crude drugs) could inhibit the stimulation induced by acetylcholine. Charred Fructus Crataegi Alcohol Extract 8 mg·mL-1(crude drugs) was found to have a inhibiton of the relaxtion concurrently used with atropin. Conclusions The results suggest that Charred Fructus Crataegi Alcohol Extract has prominent inhibitory effects on the contractile activity of isolated rat gastric and intestine smooth muscle strips.

  4. Improvement of biomass char-CO2 gasification reactivity using microwave irradiation and natural catalyst

    International Nuclear Information System (INIS)

    Highlights: • We study microwave-induced gasification of EFB ash-loaded biomass char with CO2. • Synergistic effect of microwave and catalyst resulted in CO2 conversion of 93%. • Gasification of pristine char using conventional heating gives CO2 conversion of 58%. • Ea of 74 and 247 kJ/mol were obtained for microwave and conventional CO2 gasification. - Abstract: In char-CO2 gasification, the highly endothermic nature of the Boudouard reaction (CO2 (g) + C (s) ↔ 2CO (g)) dictates use of very high temperatures to shift the equilibrium towards CO production. In this study, such high temperature (750–900 °C) was provided by microwave irradiation. A microwave heating system was developed to perform the gasification tests by passing CO2 through a packed bed of oil palm shell (OPS) char. In order to speed up the microwave-induced CO2 gasification, ash of palm empty fruit bunch (EFB) was used as natural catalyst (rich in potassium) and incorporated into the skeleton of the OPS char. The synergistic effect of microwave and catalyst concluded to very encouraging results, where a CO2 conversion of 93% was achieved at 900 °C, within 60 min microwave gasification. In comparison, CO2 conversion in thermal gasification (conventional heating) of pristine OPS char was only 58% under the same operating condition

  5. Bio-char derived from sewage sludge by liquefaction: Characterization and application for dye adsorption

    Science.gov (United States)

    Leng, Lijian; Yuan, Xingzhong; Huang, Huajun; Shao, Jianguang; Wang, Hou; Chen, Xiaohong; Zeng, Guangming

    2015-08-01

    Bio-chars produced by liquefaction of sewage sludge with methanol, ethanol, or acetone as the solvent at 260-380 °C were characterized in terms of their elemental composition, thermogravimetric characteristics, surface area and pore size distribution, and oxygen-containing functional groups composition. The surface area and total volume of the bio-chars were low, but the contents of oxygen-containing functional groups were high. The bio-chars were effective on Malachite green (MG) and Methylene blue (MB) removal from aqueous solution. The MG adsorption equilibrium data showed excellent fit to the Langmuir model and the kinetic data fitted well to the Pseudo-second-order model. Thermodynamic investigations indicated that MG adsorption on bio-char was spontaneous and endothermic. The MG adsorption mechanism appears to be associated with cation release and functional group participation. Additionally, liquefaction of SS with acetone as the solvent at low temperature (280 °C) would favor the production of bio-char adsorbent in terms of bio-char yield and MG and MB adsorption capacity.

  6. Role of char during reburning of nitrogen oxides. Ninth quarterly report, October 1, 1995--December 31, 1995

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Wei-Yin; Lu, Te-Chang [Mississippi Univ., University, MS (United States). Dept. of Chemical Engineering; Fan, L.T.; Yashima, Mutsuo [Kansas State Univ., Manhattan, KS (United States). Dept. of Chemical Engineering

    1996-01-31

    During this quarter, we have investigated rates and product compositions of NO reduction on chars in gases. N{sub 2} and CO{sub 2} internal surface areas of chars, selected from runs of various pyrolysis and reaction conditions have been measured to assist in interpreting the experimental results. Implications of Langmuir- Hinshelwood mechanisms and mass transfer limitations were examined. Oxidants suppress NO reduction on bituminous coal char more than on lignite char. Observations suggest that NO adsorption and desorption of stable surface oxygen complexes are potentially important rate- limiting steps and may be catalyzed by mineral matter during reburning with lignite char. Relative inert nature of lignite char to CO{sub 2} presence may have potential value in use of fuel system involving both solid and volatile fuels. Lignite char produced at 950 C and zero holding time has higher reactivity than that produced at 1100 C and 5 min holding time. Bituminous coal chars produced at these two conditions, however, have similar reactivity with NO. Internal surface areas of both type chars vary with pyrolysis conditions and gas composition in the subsequent reaction. When oxidants are introduced in the feed, internal surface areas of these two chars vary in opposite directions.

  7. Efficacy of Locust Beans Husk Char in Heavy Metal Sequestration

    Directory of Open Access Journals (Sweden)

    Ademola Ayodeji Ajayi-Banji

    2016-03-01

    Full Text Available Most solid waste management schemes minimally consider low concentration biodegradable agricultural waste management, though the environmental impact of this waste category is significant over a time frame. The column-mode study seeks to address the issue by suggesting potential utilisation of post-harvest waste for heavy metal sequestering. Locust beans husk char of 100 and 200 g was employed to inspect removal efficiency, isotherm and kinetic models of some heavy metals at 30, 60, 90, 120 and 150 min contact time. Elemental composition of the biosorbent was investigated using the SEM-EDX machine. The results obtained depict that over 85% aluminium and nickel removal was achieved at 150 min detention time. The Freundlich isotherm well described most of the sorbates sorption (R2 ≥ 0.91. The sorption rate equally fitted into the second-order pseudo kinetic model (R2 ≥ 0.88. Ion exchange took place during the sorption. Locust beans husk has promising adsorption potential in heavy metal ions removal from fouled surface water. DOI: http://dx.doi.org/10.5755/j01.erem.71.4.13081

  8. Coke, char and organic waste behaviour in the blast furnace with high injection rate

    Directory of Open Access Journals (Sweden)

    Gudenau, H. W.

    2003-10-01

    Full Text Available Blast furnace operation with low coke rate, high amount of auxiliary hydrocarbons and use of nut coke causes a change in coke quality requirements. In particular, not burned in the raceway residues of injected substances (char and ash can influence the coke behaviour. Therefore combustion efficiency of various organic wastes with and without pulverized coal injection (PCI and coal char has been investigated under the raceway simulation conditions. Mixing of various substances improves their combustion efficiency. Study on coke gasification by carbon dioxide in the presence of char showed that with the increase of char concentration, coke strength reduction becomes smaller. The reactivity of char with CO2 is higher than that of coke. Therefore char is consumed preferentially. In presence of injected char, total pore volume in coke and its wear resistance were increased. Coke reactivity and microstructure in the presence of various kinds of ash has been studied. Many ash spheres were observed on the surface of coke matrix and its size was dependent on ash properties.

    La operación del horno alto con una tasa baja de coque, una cantidad elevada de hidrocarburos auxiliares y el empleo de coque calibrado, origina un cambio en las necesidades de calidad del coque. En particular, pueden influir en el comportamiento del coque los residuos inquemados en el raceway (cavidad enfrente a las toberas del horno de las sustancias que se inyectan (char y cenizas. El char es el residuo de carbón que se origina después que el carbón libera sus sustancias volátiles. Por tanto, se ha investigado la eficiencia de la combustión de varios residuos orgánicos con y sin inyección de carbón pulverizado (ICP y char, bajo las condiciones de simulación del raceway. La mezcla de varias sustancias mejora la eficiencia a la combustión. El estudio de la gasificación del coque por el dióxido de carbono en la

  9. Ductile Damage and Fatigue Behavior of Semi-Finished Tailored Blanks for Sheet-Bulk Metal Forming Processes

    Science.gov (United States)

    Besserer, Hans-Bernward; Hildenbrand, Philipp; Gerstein, Gregory; Rodman, Dmytro; Nürnberger, Florian; Merklein, Marion; Maier, Hans Jürgen

    2016-03-01

    To produce parts from sheet metal with thickened functional elements, bulk forming operations can be employed. For this new process class, the term sheet-bulk metal forming has been established recently. Since sheet-bulk metal forming processes such as orbital forming generates triaxial stress and strain states, ductile damage is induced in the form of voids in the microstructure. Typical parts will experience cyclic loads during service, and thus, the influence of ductile damage on the fatigue life of parts manufactured by orbital forming is of interest. Both the formation and growth of voids were characterized following this forming process and then compared to the as-received condition of the ferritic deep drawing steel DC04 chosen for this study. Subsequent to the forming operation, the specimens were fatigued and the evolution of ductile damage and the rearrangement of the dislocation networks occurring during cyclic loading were determined. It was shown, that despite an increased ductile damage due to the forming process, the induced strain hardening has a positive effect on the fatigue life of the material. However, by analyzing the fatigued specimens a development of the ductile damage by an increasing number of voids and a change in the void shape were detected.

  10. Environmental Impacts of the Production and Application of Biochar - EuroChar Project

    Science.gov (United States)

    Rack, Mireille; Woods, Jeremy

    2014-05-01

    One of the potential benefits of biochar is carbon sequestration. To determine the overall net sequestration potential it is important to analyse the full supply chain, assessing both the direct and indirect emissions associated with the production and application of biochar. However, it is essential to also incorporate additional environmental impact categories to ensure the assessment of a more complete environmental impact profile. This paper uses a full life-cycle assessment (LCA) methodology to evaluate the results from the EuroChar, 'biochar for carbon sequestration and large-scale removal of GHG from the atmosphere', project. This EU Seventh Framework Programme project aims to investigate and reduce uncertainties around the impacts of, and opportunities for, biochar, and in particular explore possible pathways for its introduction into modern agricultural systems in Europe. The LCA methodology, according to the ISO standards, is applied to the project-specific supply chains to analyse the environmental impacts of biochar production and application. Two conversion technologies for the production of biochar are assessed, gasification and hydrothermal carbonization (HTC), in order to provide conversion efficiencies and emission factors for the biochar production component of the supply chain. The selected feedstocks include those derived from waste residues and dedicated crops. For the end use stage, various forms and methods for biochar application are considered. In addition to the Global Warming Potential category, other environmental impact categories are also included in the analysis. The resulting 'feedstock * conversion technology' matrix provides nine pathways for the production and application of biochar, which are applied as a representative basis for the scenario modelling. These scenarios have been developed in order to assess the feedstock and land availability in Europe for the production and application of biochar and to give an order of

  11. Initial Evaluation of Processing Methods for an Epsilon Metal Waste Form

    Energy Technology Data Exchange (ETDEWEB)

    Crum, Jarrod V.; Strachan, Denis M.; Zumhoff, Mac R.

    2012-06-11

    During irradiation of nuclear fuel in a reactor, the five metals, Mo, Pd, Rh, Ru, and Tc, migrate to the fuel grain boundaries and form small metal particles of an alloy known as epsilon metal ({var_epsilon}-metal). When the fuel is dissolved in a reprocessing plant, these metal particles remain behind with a residue - the undissolved solids (UDS). Some of these same metals that comprise this alloy that have not formed the alloy are dissolved into the aqueous stream. These metals limit the waste loading for a borosilicate glass that is being developed for the reprocessing wastes. Epsilon metal is being developed as a waste form for the noble metals from a number of waste streams in the aqueous reprocessing of used nuclear fuel (UNF) - (1) the {var_epsilon}-metal from the UDS, (2) soluble Tc (ion-exchanged), and (3) soluble noble metals (TRUEX raffinate). Separate immobilization of these metals has benefits other than allowing an increase in the glass waste loading. These materials are quite resistant to dissolution (corrosion) as evidenced by the fact that they survive the chemically aggressive conditions in the fuel dissolver. Remnants of {var_epsilon}-metal particles have survived in the geologically natural reactors found in Gabon, Africa, indicating that they have sufficient durability to survive for {approx} 2.5 billion years in a reducing geologic environment. Additionally, the {var_epsilon}-metal can be made without additives and incorporate sufficient foreign material (oxides) that are also present in the UDS. Although {var_epsilon}-metal is found in fuel and Gabon as small particles ({approx}10 {micro}m in diameter) and has survived intact, an ideal waste form is one in which the surface area is minimized. Therefore, the main effort in developing {var_epsilon}-metal as a waste form is to develop a process to consolidate the particles into a monolith. Individually, these metals have high melting points (2617 C for Mo to 1552 C for Pd) and the alloy is

  12. Effect of reduction roasting by using bio-char derived from empty fruit bunch on the magnetic properties of Malaysian iron ore

    Institute of Scientific and Technical Information of China (English)

    Nurul A. Yunus; Mohd H. Ani; Hamzah M. Salleh; Rusila Z. A. Rashid; Tomohiro Akiyama; Hadi Purwanto; Nur E. F. Othman

    2014-01-01

    Beneficiation of Malaysian iron ore is becoming necessary as iron resources are depleting. However, the upgrading process is challenging because of the weak magnetic properties of Malaysian iron ore. In this study, bio-char derived from oil palm empty fruit bunch (EFB) was utilized as an energy source for reduction roasting. Mixtures of Malaysian iron ore and the bio-char were pressed into briquettes and subjected to reduction roasting processes at 873-1173 K. The extent of reduction was estimated on the basis of mass loss, and the mag-netization of samples was measured using a vibrating sample magnetometer (VSM). When reduced at 873 K, the original goethite-rich ore was converted into hematite. An increase in temperature to 1073 K caused a significant conversion of hematite into magnetite and enhanced the magnetic susceptibility and saturation magnetization of samples. The magnetic properties diminished at 1173 K as the iron ore was par-tially reduced to wustite. This reduction roasting by using the bio-char can assist in upgrading the iron ore by improving its magnetic proper-ties.

  13. Phosphate-induced metal stabilization: Use of apatite and bone char for the removal of soluble radionuclides in authentic and simulated DOE groundwater

    International Nuclear Information System (INIS)

    The apatite group of minerals is a family of calcium phosphate phases. Apatite is the principal component of bone tissue, and it also occurs naturally as mineral deposits in the geosphere. Bone char is calcined (coked) animal bone, containing activated carbon as well as calcium phosphate mineral phases. Apatite IItrademark is a more reactive form of apatite, supplied by UFA Ventures, Inc., at a cost of approximately 1/4 that of commercial bone char. Apatite is shown to be effective for the removal of select heavy metal impurities in groundwater. Previous investigations have demonstrated that apatite is an effective medium for the stabilization of soluble lead, cadmium, and zinc from mine waste leachate by the formation of highly insoluble precipitate phases. The performance of bone char and apatite II are compared with other candidate sorption media (including granular activated carbon and anion exchange resin) for the removal of soluble uranyl ion in synthetic DOE Site groundwater supplemented with varying levels of interfering nitrate ion. Apatite II has a greater affinity for U(VI), especially in the presence of nitrate ion, as evidenced by a larger value for the conditional distribution coefficient (Kd) in batch test experiments. Contact of uranyl nitrate solution with apatite II is shown to produce highly insoluble mineral phases of the autunite group (calcium uranyl phosphate hydrates). Apatite II is also demonstrated to be moderately effective for the removal of soluble radioactive isotopes of strontium, but not cesium, when these ions are supplemented into authentic DOE Site groundwater

  14. Numerical simulation of the bulk forming processes for 1345 aluminum alloy billets

    Directory of Open Access Journals (Sweden)

    Fakhreddine. KHEROUF

    2015-08-01

    Full Text Available This paper presents an improved numerical simulation of bulk metal forming processes. It takes into the account the advanced formalism of large displacements and large deformations. Also, the interface workpiece formalism in considered. Metallographic studies are conducted to determine the evolution of the micro hardness as a function of annealing time and that to characterize accurately the plastic range of aluminum alloy for a range of plasticity 120%. The obtained results of metallographic studies are used to simulate a hot upsetting under the friction law of the plastic wave. Several simulations of forging operations of an axisymmetric billet by a rigid axisymmetric conical tool are performed with ABAQUS/standard computer code and that for preheated billets from 20 °C to 500 °C. The numerical study of the evolution of the normal stress at the interface has shown that the latter is independent of the tool roughness for a temperature close to 500 °C. The numerical study also allowed us to define the three areas of forging whatever cold; warm and hot forging. The effects of friction coefficient on the metal flow and contact pressure are numerically explored.

  15. Microstructure and electrical conductivity of Al–SiCp composites produced by spray forming process

    Indian Academy of Sciences (India)

    V C Srivastava; S N Ojha

    2005-04-01

    Al–SiCp composites have been synthesized by spray forming process with variation in particle flow rate, size of reinforcement particles and their volume fraction. The microstructure of composites and their electrical conductivity have been investigated. The results showed a uniform dispersion of large size particulate phase in the matrix of the primary -phase with its equiaxed grain morphology. However, clustering of small size particles was observed at the grain boundary and grain junctions. The grain size of the composite materials was observed to be lower than that of the base Al-alloy. The composite materials invariably indicated their lower electrical conductivity compared to that of the monolithic Al-alloy. The electrical conductivity of composites decreased with increase in the volume fraction and decrease in size of the reinforcement particles. A high flow rate of particles during spray deposition resulted in a decrease in its conductivity. These results are explained in the light of thermal mismatch between the matrix and the reinforcement phases resulting in generation of high dislocation density. The droplet-particle interaction and resulting microstructure evolution during the spray deposition of the composites are discussed.

  16. The Role of Sexual Disorder in FormingDivorce Process: a Grounded Theory Study

    Directory of Open Access Journals (Sweden)

    H enayat

    2016-03-01

    Full Text Available Background & Aim: consequences resulting in the increase of the divorce rate in the Iranian society, which surrounded all individuals, families and society, has prepared the background of the present study. The main purpose of the present study was demonstrating a paradigm model of the role of sexual disorder in forming the divorce process among men in Iran. Method: The present study was conducted by applying a qualitative method using the grounded theory approach in Gachsaran, Iran, in 2014. The participants of the study were 15 divorced men who were selected using purposeful sampling. Data were gathered using depth interview, and were analyzed with coding paradigm. Results: according to the coding paradigm, men's sexual dysfunctional as a causal condition, physical disease, mind stress, and age difference between couples as a contextual condition, culture of drug abuse for satisfaction of sexual relation, and infidelity as an interventional condition, caused disorder in their sexual relationship. These men and their wives applied various strategies, such as drug abuse, disconnected sexual relation with each other, and latent violence in order to counteract this phenomenon. Conclusion: The narrative of participants of the present study revealed that disorder in their sexual relation led to other social problems, such as drug abuse, domestic violence, and infidelity in their families. Moreover, these problems led to other disorders in their sexual relationship with their wives, which eventually ended to emotional, sexual and legal divorce.

  17. Formation and magic number characteristics of clusters formed during solidification processes

    International Nuclear Information System (INIS)

    A molecular dynamics simulation study has been performed for a large-sized system consisting of 106 liquid metal Al atoms to investigate the formation and magic number characteristics of various clusters formed during solidification processes. The cluster-type index method (CTIM) is adopted to describe various types of cluster by basic clusters. It is demonstrated that the icosahedral cluster (12 0 12 0) is the most important basic cluster, and that it plays a critical role in the microstructure transition. A new statistical method has been proposed to classify the clusters as some group levels according to the numbers of basic clusters contained in each cluster. The magic numbers can be determined by the respective peak value positions of different group levels of clusters, and the magic number sequence in the system is 13, 19, 25(27), 31(33), 38(40), 42(45), 48(51), 55(59), 61(65), 67,... the numbers in the brackets are the second magic number of the corresponding group levels of clusters. This magic number sequence is in good agreement with the experimental results obtained by Schriver and Harris et al, and the experimental results can be reasonably well explained

  18. Effects of forming processing conditions on the flexural properties of bagasse and bamboo plastic composites

    Directory of Open Access Journals (Sweden)

    Shinichi Shibata

    2012-11-01

    Full Text Available The effects of processing conditions such as pressure, temperature, and holding time on the flexural properties of bagasse and bamboo biodegradable composites were investigated. Each sample of bagasse or bamboo was mixed with a corn-starch-based biodegradable resin and fabricated by a hot press forming method. The cross-sectional structure of the bagasse fiber was found to be porous and compressible, while that of bamboo was found to be more solid. The relationship between flexural strength, flexural modulus, and pressure in bagasse fiber was apparently different from that of bamboo due to the differences in the cross-sectional structure. In bagasse, the flexural strength and flexural modulus increased with the increase in pressure, whereas in bamboo those properties decreased. In bagasse, an increase in pressure made the fibers into a more compressed structure, increasing their flexural properties. In rigid bamboo, an increase in pressure caused the resin to extrude between fibers, and this resulted in lower flexural properties. At temperatures above 170 oC, the resin depolymerized thermally and the degree of polymerization decreased. Thus, the flexural modulus and strength decreased gradually with increase in holding temperature in both bagasse and bamboo composites. Furthermore, a maximum fiber volume fraction existed for both bagasse and bamboo plastic composites in the approximate range of 75% to 80%.

  19. Measurements of Gasification Characteristics of Coal and Char in CO2-Rich Gas Flow by TG-DTA

    Directory of Open Access Journals (Sweden)

    Zhigang Li

    2013-01-01

    Full Text Available Pyrolysis, combustion, and gasification properties of pulverized coal and char in CO2-rich gas flow were investigated by using gravimetric-differential thermal analysis (TG-DTA with changing O2%, heating temperature gradient, and flow rate of CO2-rich gases provided. Together with TG-DTA, flue gas generated from the heated coal, such as CO, CO2, and hydrocarbons (HCs, was analyzed simultaneously on the heating process. The optimum O2% in CO2-rich gas for combustion and gasification of coal or char was discussed by analyzing flue gas with changing O2 from 0 to 5%. The experimental results indicate that O2% has an especially large effect on carbon oxidation at temperature less than 1100°C, and lower O2 concentration promotes gasification reaction by producing CO gas over 1100°C in temperature. The TG-DTA results with gas analyses have presented basic reference data that show the effects of O2 concentration and heating rate on coal physical and chemical behaviors for the expected technologies on coal gasification in CO2-rich gas and oxygen combustion and underground coal gasification.

  20. Modeling the Pyrolysis and Combustion Behaviors of Non-Charring and Intumescent-Protected Polymers Using “FiresCone”

    Directory of Open Access Journals (Sweden)

    Long Shi

    2015-10-01

    Full Text Available A mathematical model, named FiresCone, was developed to simulate the pyrolysis and combustion processes of different types of combustible materials, which also took into account both gas and solid phases. In the present study, some non-charring and intumescent-protected polymer samples were investigated regarding their combustion behaviors in response to pre-determined external heat fluxes. The modeling results were validated against the experimental outcomes obtained from a cone calorimeter. The predicted mass loss rates of the samples were found to fit reasonably well with the experimental data collected under various levels of external irradiation. Both the experimental and modeling results showed that the peak mass loss rate of the non-charring polymer material occurred near the end of burning, whereas for the intumescent-protected polymer it happed shortly after the start of the experiment. “FiresCone” is expected to act as a practical tool for the investigation of fire behavior of combustible materials. It is also expected to model fire scenarios under complicated conditions.

  1. Conversion of char nitrogen to N2 under incomplete combustion conditions; Fukanzen nensho jokenka ni okeru char chuchisso no N2 eno tenka

    Energy Technology Data Exchange (ETDEWEB)

    Zhuang, Q.; Yamauchi, A.; Oshima, Y.; Wu, Z.; Otsuka, Y. [Tohoku University, Sendai (Japan). Institute for Chemical Reaction Science

    1996-10-28

    The effect of combustion conditions on conversion of char nitrogen to N2 was studied in the combustion experiment of char obtained by pyrolysis of coal. Char specimen was prepared by holding ZN coal of Chinese lignite in Ar atmosphere at 1123K for one hour. A batch scale quartz-made fluidized bed reactor was used for combustion experiment. After the specimen was fluidized in reaction gas, it was rapidly heated to start combustion reaction. CO, CO2 and N2 in produced gases were online measured by gas chromatography (GC). As the experimental result, under the incomplete combustion condition where a large amount of CO was produced by consuming almost all of O2, no NOx and N2O produced from char were found, and almost all of N-containing gas was N2. At the final stage of combustion, pyridinic-N disappeared completely, and pyrrolic-N decreased, while O-containing nitrogen complexes became a main component. It was thus suggested that O-containing nitrogen complexes are playing the role of intermediate product in combustion reaction. 7 refs., 4 figs., 1 tab.

  2. 32 CFR Appendix C to Part 286 - DD Form 2086, “Record of Freedom of Information (FOI) Processing Cost”

    Science.gov (United States)

    2010-07-01

    ... 32 National Defense 2 2010-07-01 2010-07-01 false DD Form 2086, âRecord of Freedom of Information (FOI) Processing Costâ C Appendix C to Part 286 National Defense Department of Defense (Continued... INFORMATION ACT PROGRAM REGULATION Pt. 286, App. C Appendix C to Part 286—DD Form 2086, “Record of Freedom...

  3. Comparison of high temperature chars of wheat straw and rice husk with respect to chemistry, morphology and reactivity

    DEFF Research Database (Denmark)

    Trubetskaya, Anna; Jensen, Peter Arendt; Jensen, Anker Degn;

    2016-01-01

    Fast pyrolysis of wheat straw and rice husk was carried out in an entrained flow reactor at hightemperatures(1000e1500) C. The collected char was analyzed using X-ray diffractometry, N2-adsorption,scanning electron microscopy, particle size analysis with CAMSIZER XT, 29Si and 13C solid-statenucle......Fast pyrolysis of wheat straw and rice husk was carried out in an entrained flow reactor at hightemperatures(1000e1500) C. The collected char was analyzed using X-ray diffractometry, N2-adsorption,scanning electron microscopy, particle size analysis with CAMSIZER XT, 29Si and 13C solid......), which led to the formation of a glassy char shell, resulting in a preserved particlesize and shape of chars. The high alkali content in the wheat straw resulted in higher char reactivity,whereas the lower silicon content caused variations in the char shape from cylindrical to near...

  4. The effect of 150μm expandable graphite on char expansion of intumescent fire retardant coating

    Energy Technology Data Exchange (ETDEWEB)

    Ullah, Sami, E-mail: samichemist1@gmail.com; Shariff, A. M., E-mail: azmish@petronas.com.my, E-mail: azmibustam@petronas.com.my; Bustam, M. A., E-mail: azmish@petronas.com.my, E-mail: azmibustam@petronas.com.my [Research Center for Carbon Dioxide Capture, Department of Chemical Engineering, Universiti Techologi PETRONAS, Bandar Sri Iskandar, Tronoh 31750 Perak (Malaysia); Ahmad, Faiz, E-mail: faizahmadster@gmail.com [Department of Mechanical Engineering, Universiti Techologi PETRONAS, Bandar Sri Iskandar, Tronoh 31750 Perak (Malaysia)

    2014-10-24

    Intumescent is defined as the swelling of certain substances to insulate the underlying substrate when they are heated. In this research work the effect of 150μm expandable graphite (EG) was studied on char expansion, char morphology and char composition of intumescent coating formulations (ICFs). To study the expansion and thermal properties of the coating, nine different formulations were prepared. The coatings were tested at 500 °C for one hour and physically were found very stable and well bound with the steel substrate. The morphology was studied by Scanning Electron Microscopy (SEM). The char composition was analysed by X-ray Diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) techniques. EG above than 10.8wt% expands the char abruptly with uniform network structure and affect the outer surface of the char.

  5. Using BPCA and pyrolysis-GC/MS patterns as a measure of charring intensity

    Science.gov (United States)

    Kaal, Joeri; Schneider, Maximilian P. W.; Schmidt, Michael W. I.

    2010-05-01

    Many questions remain on the molecular properties of Black C (organic fire residues such as charcoal and soot). Here we compare parameters from two methods that have recently shown to be related to the degree of thermal modification ("charring intensity") of charcoal-Black C: i) the proportion of mellitic acid (B6CA) among benzenepolycarboxylic acids in the BPCA method [1,2,3] and ii) the relative proportions and degree of alkylation of pyrolysis products from Black C in pyrolysis-GC/MS [4]. For that purpose we used laboratory chars from rice straw (grass) and chestnut wood (wood) produced at 200-1000 °C under N2 flow. The chars obtained at 450 °C are reference materials of the Black Carbon Ring Trial [5]. Positive correlations between the charring temperature and BPCA and pyrolysis patterns confirm that these methods can be used to study the degree of thermal impact of charred remains. Pyrolysis-GC/MS allowed us to track the thermal degradation of the major biocomponents lignin, polysaccharides, tannin, aliphatic chain lipids, triterpenoids, chlorophyll and proteins, mostly between 250 and 450 °C. The proportions of the pyrolysis products of Black C (benzene, toluene, benzonitrile, PAHs, etc.) and also the ratios that reflect the abundance of aliphatic cross-linkages between aromatic moieties (benzene/toluene, naphthalene/alkylnaphthalenes, benzofuran/alkylbenzofurans), increase with charring intensity. Nonetheless, chars obtained at T > 600 °C (especially for wood) gave low quality pyrograms and poor reproducibility because of high thermal stability. The relative contributions of B6CA, one of the molecular markers used for the BPCA method, are indicative for the degree of condensation of the chars. The BPCA approach showed a clear increase in the relative contribution of B6CA from ca. 5 % at 200 °C to ca. 95 % at 1000 °C, confirming the ability of this parameter to assess charring intensity. The relative contribution of B6CA remains almost constant at ca

  6. Geobiology of the Critical Zone: the Hierarchies of Process, Form and Life provide an Integrated Ontology

    Science.gov (United States)

    Cotterill, Fenton P. D.

    2016-04-01

    through to continental scales). Our ability to reconstruct narratives of landscape dynamics of encompassing - mega-geomorphic - patterns can only be as good as the details of individual events we can discern in Earth history. Obviously, recognizing the centrality of "Conquering the Mesoscale" as the intrinsic prerequisite to test competing hypotheses of landscape dynamics, in the earth system context, calls for innovative research approaches. This is where Africa holds vast potential. The continent is the most remarkable natural laboratory to explore and tackle these challenges where we seek to build the composite mega-geomorphic chronicle informed in the detail of mesoscale process and form. But how does geomorphology, embedded in an earth system framework, advance beyond the established approaches in process and mega-geomorphology? The latter's limitations to reconstruct the tempo and mode of African landforms and palaeoenviroments reveal the stark limits for researchers. This is where a geobiological approach brings interesting opportunities, especially for Africa. Consider, for one, the interlinking patterns of high endemism and geographical heterogeneity of extant biodiversity across the continent, and moreover the interplay in biotic turnovers since the Mesozoic that shaped these regional and more local patterns. These individuated biotic assemblages making up the continent's biomes and ecoregions reveal strident congruence with physiographic controls: especially relief, drainage and edaphic variables. Calibrated by molecular clocks, resolved with DNA evidence, timetrees of this phylogenetic diversity reveal a richness of evolutionary signals; the spectrum of these spectacular biotic radiations of African biodiversity range from the Late Mesozoic to Recent. The temporal spread of this phylogenetic diversity is exemplified, for example, in the extant mammal fauna: witness the Afrotheria compared to the Bovidae (Kingdon J et al. 2013. Mammals of Africa. Bloomsbury

  7. Pyrolysis processing for solid waste resource recovery

    Science.gov (United States)

    Serio, Michael A. (Inventor); Kroo, Erik (Inventor); Wojtowicz, Marek A. (Inventor); Suuberg, Eric M. (Inventor)

    2007-01-01

    Solid waste resource recovery in space is effected by pyrolysis processing, to produce light gases as the main products (CH.sub.4, H.sub.2, CO.sub.2, CO, H.sub.2O, NH.sub.3) and a reactive carbon-rich char as the main byproduct. Significant amounts of liquid products are formed under less severe pyrolysis conditions, and are cracked almost completely to gases as the temperature is raised. A primary pyrolysis model for the composite mixture is based on an existing model for whole biomass materials, and an artificial neural network models the changes in gas composition with the severity of pyrolysis conditions.

  8. Pyrolysis process for producing fuel gas

    Science.gov (United States)

    Serio, Michael A. (Inventor); Kroo, Erik (Inventor); Wojtowicz, Marek A. (Inventor); Suuberg, Eric M. (Inventor)

    2007-01-01

    Solid waste resource recovery in space is effected by pyrolysis processing, to produce light gases as the main products (CH.sub.4, H.sub.2, CO.sub.2, CO, H.sub.2O, NH.sub.3) and a reactive carbon-rich char as the main byproduct. Significant amounts of liquid products are formed under less severe pyrolysis conditions, and are cracked almost completely to gases as the temperature is raised. A primary pyrolysis model for the composite mixture is based on an existing model for whole biomass materials, and an artificial neural network models the changes in gas composition with the severity of pyrolysis conditions.

  9. Char characterization and DTF assays as tools to predict burnout of coal blends in power plants

    Energy Technology Data Exchange (ETDEWEB)

    C. Ulloa; A.G. Borrego; S. Helle; A.L. Gordon; X. Garcia [Universidad de Concepcion, Concepcion (Chile). Departamento de Ingenieria Quimica

    2005-02-01

    The aim of this study is to predict efficiency deviations in the combustion of coal blends in power plants. Combustion of blends, as compared to its single coals, shows that for some blends the behavior is non-additive in nature. Samples of coal feed and fly ashes from combustion of blends at two power plants, plus chars of the parent coals generated in a drop-tube furnace (DTF) at temperatures and heating rates similar to those found in the industrial boilers were used. Intrinsic kinetic parameters, burning profiles and petrographic characteristics of these chars correlated well with the burnout in power plants and DTF experiments. The blend combustion in a DTF reproduces both positive and negative burnout deviations from the expected weighted average. These burnout deviations have been previously attributed to parallel or parallel-series pathways of competition for oxygen. No deviations were found for blends of low rank coals of similar characteristics yielding chars close in morphology, optical texture and reactivity. Negative deviations were found for blends of coals differing moderately in rank and were interpreted as associated with long periods of competition. In this case, fly-ashes were enriched in material derived from the least reactive char, but also unburnt material attributed to the most reactive char was identified. Improved burnout compared to the weighted average was observed for blends of coals very different in rank, and interpreted as the result of a short interaction period, followed by a period where the less reactive char burns under conditions that are more favorable to its combustion. In this case, only unburned material from the least reactive char was identified in the fly-ashes. 20 refs., 9 figs., 5 tabs.

  10. Computational investigations of low-emission burner facilities for char gas burning in a power boiler

    Science.gov (United States)

    Roslyakov, P. V.; Morozov, I. V.; Zaychenko, M. N.; Sidorkin, V. T.

    2016-04-01

    Various variants for the structure of low-emission burner facilities, which are meant for char gas burning in an operating TP-101 boiler of the Estonia power plant, are considered. The planned increase in volumes of shale reprocessing and, correspondingly, a rise in char gas volumes cause the necessity in their cocombustion. In this connection, there was a need to develop a burner facility with a given capacity, which yields effective char gas burning with the fulfillment of reliability and environmental requirements. For this purpose, the burner structure base was based on the staging burning of fuel with the gas recirculation. As a result of the preliminary analysis of possible structure variants, three types of early well-operated burner facilities were chosen: vortex burner with the supply of recirculation gases into the secondary air, vortex burner with the baffle supply of recirculation gases between flows of the primary and secondary air, and burner facility with the vortex pilot burner. Optimum structural characteristics and operation parameters were determined using numerical experiments. These experiments using ANSYS CFX bundled software of computational hydrodynamics were carried out with simulation of mixing, ignition, and burning of char gas. Numerical experiments determined the structural and operation parameters, which gave effective char gas burning and corresponded to required environmental standard on nitrogen oxide emission, for every type of the burner facility. The burner facility for char gas burning with the pilot diffusion burner in the central part was developed and made subject to computation results. Preliminary verification nature tests on the TP-101 boiler showed that the actual content of nitrogen oxides in burner flames of char gas did not exceed a claimed concentration of 150 ppm (200 mg/m3).

  11. Gasification of the char derived from distillation of granulated scrap tyres.

    Science.gov (United States)

    López, Félix A; Centeno, Teresa A; Alguacil, Francisco José; Lobato, Belén; López-Delgado, Aurora; Fermoso, Javier

    2012-04-01

    This work reports the effect of pressure on the steam/oxygen gasification at 1000°C of the char derived from low temperature-pressure distillation of granulated scrap tyres (GST). The study was based on the analysis of gas production, carbon conversion, cold gas efficiency and the high heating value (HHV) of the product. For comparison, similar analyses were carried out for the gasification of coals with different rank. In spite of the relatively high ash (≈12 wt.%) and sulphur (≈3 wt.%) contents, the char produced in GST distillation can be regarded as a reasonable solid fuel with a calorific value of 34MJkg(-1). The combustion properties of the char (E(A)≈50 kJ mol(-1)), its temperature of self-heating (≈264°C), ignition temperature (≈459°C) and burn-out temperature (≈676°C) were found to be similar to those of a semi-anthracite. It is observed that the yield, H(2) and CO contents and HHV of the syngas produced from char gasification increase with pressure. At 0.1 MPa, 4.6 Nm(3)kg(char)(-1) of syngas was produced, containing 28%v/v of H(2) and CO and with a HHV around 3.7 MJ Nm(-3). At 1.5 MPa, the syngas yield achieved 4.9N m(3)kg(char)(-1) with 30%v/v of H(2)-CO and HHV of 4.1 MJ Nm(-3). Carbon conversion significantly increased from 87% at 0.1 MPa to 98% at 1.5 MPa. It is shown that the char derived from distillation of granulated scrap tyres can be further gasified to render a gas of considerable heating value, especially when gasification proceeds at high pressure.

  12. A Study on Contour of Workpiece According to the Shape of Forming Coil in EMF Process

    OpenAIRE

    Choi, Y.; Kang, B Y; Kim, I S; Park, D. H.; Shim, J. Y.

    2012-01-01

    Aluminium alloys is desirable for the automotive and electronic appliances industries due to their high strength-to-weight ratio, corrosion resistance and weldability. However applications of the aluminium alloys were very difficult because aluminium alloys formability is very low at room temperature, despite their advantages. One of the high speed forming technologies is Electromagnetic Metal Forming (EMF), which can be useful forming method for low formability light-weight ma...

  13. Description of Defense Waste Processing Facility reference waste form and canister. Revision 1

    Energy Technology Data Exchange (ETDEWEB)

    Baxter, R.G.

    1983-08-01

    The Defense Waste Processing Facility (DWPF) will be located at the Savannah River Plant in Aiken, SC, and is scheduled for construction authorization during FY-1984. The reference waste form is borosilicate glass containing approx. 28 wt % sludge oxides, with the balance glass frit. Borosilicate glass was chosen because of its high resistance to leaching by water, its relatively high solubility for nuclides found in the sludge, and its reasonably low melting temperature. The glass frit contains about 58% SiO/sub 2/ and 15% B/sub 2/O/sub 3/. Leachabilities of SRP waste glasses are expected to approach 10/sup -8/ g/m/sup 2/-day based upon 1000-day tests using glasses containing SRP radioactive waste. Tests were performed under a wide variety of conditions simulating repository environments. The canister is filled with 3260 lb of glass which occupies about 85% of the free canister volume. The filled canister will generate approx. 470 watts when filled with oxides from 5-year-old sludge and 15-year-old supernate from the sludge and supernate processes. The radionuclide content of the canister is about 177,000 ci, with a radiation level of 5500 rem/h at canister surface contact. The reference canister is fabricated of standard 24-in.-OD, Schedule 20, 304L stainless steel pipe with a dished bottom, domed head, and a combined lifting and welding flange on the head neck. The overall canister length is 9 ft 10 in. with a 3/8-in. wall thickness. The 3-m canister length was selected to reduce equipment cell height in the DWPF to a practical size. The canister diameter was selected as an optimum size from glass quality considerations, a logical size for repository handling and to ensure that a filled canister with its double containment shipping cask could be accommodated on a legal-weight truck. The overall dimensions and weight appear to be compatible with preliminary assessments of repository requirements. 10 references.

  14. Process for forming exoergic structures with the use of a plasma

    Science.gov (United States)

    Kelly, M.D.

    1987-05-29

    A method of forming exoergic structures, as well as exoergic structures produced by the method, is provided. The method comprises the steps of passing a plasma-forming gas through a plasma spray gun, forming a plasma spray, introducing exoergic material into the plasma spray and directing the plasma spray toward a substrate, and allowing the exoergic material to become molten in the plasma spray and to thereafter impinge on the substrate to form a solid mass of exoergic material, the shape of which corresponds to the shape of the substrate.

  15. 78 FR 21912 - Proposed Information Collection; Comment Request; Processed Products Family of Forms

    Science.gov (United States)

    2013-04-12

    ... Products Family of Forms AGENCY: National Oceanic and Atmospheric Administration (NOAA), Commerce. ACTION...: Regular submission (extension of a current information collection). Affected Public: Business or other...

  16. OPTIMIZATION OF CATAMARAN DEMIHULL FORM IN EARLY STAGES OF THE DESIGN PROCESS

    Directory of Open Access Journals (Sweden)

    Muhammad Iqbal

    2014-10-01

    Full Text Available The amounts of research about catamaran have generated a practical formula to simplify the calculations of catamaran resistance. Ship designer will calculate the predictions of catamaran resistance rapidly. The aim of this research is focused to search the optimal demihull form where the hull form has the lowest resistance compared to other hull form models with the same displacement. To generate the different hull form, the initial hull form (parent hull is transformed so that become some models by changing the parameter of coefficient block (Cb in range ±10% with Lwl, T, H, volume and displacement are constant. The transformed hull form are calculated their total resistance from Froude number (Fr 0,2 to 0,65 with spacing hull to length ratio (S/L 0,2 to 0,4. The results of calculation show that the optimal demihull form is Model 4 where the initial hull form Cb +5%. The model has the lowest resistance compared to other models. The comparisons of resistance Model 4 with the configurations of S/L shows that the lowest resistance is S/L 0,4, so that the optimal demihull form is Model 4 with S/L 0,4.

  17. Combinations of synergistic interactions and additive behavior during the co-oxidation of chars from lignite and biomass

    Energy Technology Data Exchange (ETDEWEB)

    Haykiri-Acma, H.; Yaman, S. [Istanbul Technical University, Chemical and Metallurgical Engineering Faculty, Chemical Engineering Department, 34469, Maslak, Istanbul (Turkey)

    2008-02-15

    The aim of this study is to investigate the co-combustion behavior of two different pyrolytic chars. For this purpose, Elbistan lignite and woody shells of hazelnut were pyrolysed in a tube furnace by heating to 900 C with a heating rate of 40 C min{sup -} {sup 1} under dynamic nitrogen flow of 400 mL min{sup -} {sup 1} to obtain pyrolytic char. These chars were mixed to obtain blends having the biomass char in the ratios of 5, 10, and 20 wt.%. Non-isothermal DTA and TGA profiles of the chars were obtained from ambient to 900 C with a heating rate of 40 C min{sup -} {sup 1} under the static ambient atmosphere. DTA and TGA profiles of the blend chars were interpreted considering the thermal characteristics such as ignition point, burnout at a given temperature, maximum burning rate, the end of combustion etc. Relations between the fraction of the biomass char in the blends and the thermal behavior of the blends were evaluated according to the synergistic approach. It was found that addition of biomass char led to important variations in some thermal properties which can not be explained by the additive behavior. However it can be concluded in general that the combinations of synergistic interactions and additive behavior govern the thermal properties of the blend chars during co-oxidation. (author)

  18. In situ catalyzed Boudouard reaction of coal char for solid oxide-based carbon fuel cells with improved performance

    International Nuclear Information System (INIS)

    Highlights: • Industrial coal char was used as a fuel for solid oxide-based carbon fuel cells. • The Boudouard reactivity of coal char is higher than that of a commercial activated carbon. • The mineral matter in coal char has a catalytic effect on the Boudouard reaction. • Added catalysts and the inherent catalysts synergetically improved cell output. - Abstract: The use of industrial coal char as a fuel source for an anode-supported solid oxide-based carbon fuel cell (SO-CFC) with a yttrium-stabilized zirconia electrolyte and La0.8Sr0.2MnO3 cathode was investigated. Both the Boudouard reactivity and electrochemical performance of the coal char samples are higher than those of activated carbon samples under the same conditions. The inherent catalytic activity of the metal species (FemOn, CaO, etc.) in the coal char mineral matter leads to good cell performance, even in the absence of an external catalyst. For example, the peak power density of a cell fueled with pure coal char is 100 mW cm−2 at 850 °C, and that of a cell fueled with coal char impregnated with an FemOn-alkaline metal oxide catalyst is 204 mW cm−2. These results suggest that using coal char as the fuel in SO-CFCs might be an attractive way to utilize abundant coal resources cleanly and efficiently, providing an alternative for future power generation

  19. Validation tool for 2D multi-stage metal-forming processes on meta-stable stainless steels

    NARCIS (Netherlands)

    Post, J.; Vries, de C.; Huetink, J.

    2009-01-01

    During the last few years it has become more and more customary for major industries to use FEM simulations during the product creation process. Most of these metal-forming process simulations are based on elastic plastic behaviour of material and use non-deformable tools. For a correct use of FEM s

  20. Actuality of problem of forming social health of future teachers in the process of physical education.

    Directory of Open Access Journals (Sweden)

    Nikiforov A. E.

    2012-06-01

    Full Text Available The issues of the day of forming social health of future teachers are considered. The value of social health for the student of both personality and in the context of professional activity of future teacher is resulted. The place of physical education opens up in forming of social health of students of pedagogical specialities. It is set that an important value has forming of social health of students of pedagogical speciality in the context of future professional activity. It is marked that on formed of social health of future teacher education of the comprehensively developed and healthy young people depends in a great deal. It is set that an important value in forming of social health of students plays physical education due to the use of his potential and complete orientation in the noted direction.

  1. Badlands: Regolith, Forms and Processes. A review of the scientific research in Spain

    Science.gov (United States)

    Nadal-Romero, Estela; Cerdà, Artemi

    2014-05-01

    Badlands are usually defined as 'intensely dissected natural landscapes where vegetation is sparse or absent and which are useless for agriculture' (Bryan and Yair, 1982). Badlands are widerspread around the world (Nadal-Romero, 2007; Dickie and Parsons, 2012; Haregeweyn et al., 2012). In Spain due to the climatic and geological conditions badlands are widespread. Badlands research has national and foreign pioneers (Harvey, 1982; Clotet et al., 1988; Alexander and Calvo, 1990; Calvo et al., 1991; Alexander et al., 1994). Almería, Granada, Murcia, Alicante, the Ebro Valley, and the Pyrenees are good examples of the variety and diversity of badlands in Spain (García-Ruiz and López-Bermúdez, 2009). The research on badlands paid attention to the infiltration and runoff generation (Cerdà, 1999a), piping (Romero-Diaz et al., 2011), the role of parent material on the regolith morphology (Regués, 1995; Cerdà, 1998b) and the soil development (Regués, 1993), and the interaction of the vegetation and soil erosion (Cerdà and García Fayos, 1997; Solé et al., 1997) vegetation varied, whereas the percentage of studies on erosion rates increased steadily over time. During the 90s badlands research was flowering and research on badlands developments, forms and soil physical properties influence was done. The 00's were a period with research focused on processes (infiltration, runoff and erosion) but in general the interest on badland decreased. However, badlands are intensively researched in the Ebro Valley (Nadal-Romero et al., 2007; 2008; Nadal-Romero and Regués; 2009; 2010) and new research is being developed on degraded soils following the knowledge found on badlands (Cerdà, 2007; García Fayos et al., 2010). The future is moving to study vegetation dynamics and badlands reclamation, the effect of climatic change in badland areas, and erosion processes and rates (Nadal-Romero et al., 2013). The use of new non-invasive technologies (remote sensing, Terrestrial Laser

  2. Peroxide-assisted microwave activation of pyrolysis char for adsorption of dyes from wastewater.

    Science.gov (United States)

    Nair, Vaishakh; Vinu, R

    2016-09-01

    In this study, mesoporous activated biochar with high surface area and controlled pore size was prepared from char obtained as a by-product of pyrolysis of Prosopis juliflora biomass. The activation was carried out by a simple process that involved H2O2 treatment followed by microwave pyrolysis. H2O2 impregnation time and microwave power were optimized to obtain biochar with high specific surface area and high adsorption capacity for commercial dyes such as Remazol Brilliant Blue and Methylene Blue. Adsorption parameters such as initial pH of the dye solution and adsorbent dosage were also optimized. Pore size distribution, surface morphology and elemental composition of activated biochar were thoroughly characterized. H2O2 impregnation time of 24h and microwave power of 600W produced nanostructured biochar with narrow and deep pores of 357m(2)g(-1) specific surface area. Langmuir and Langmuir-Freundlich isotherms described the adsorption equilibrium, while pseudo second order model described the kinetics of adsorption. PMID:27268436

  3. Tetracycline adsorption onto activated carbons produced by KOH activation of tyre pyrolysis char.

    Science.gov (United States)

    Acosta, R; Fierro, V; Martinez de Yuso, A; Nabarlatz, D; Celzard, A

    2016-04-01

    Tyre pyrolysis char (TPC), produced when manufacturing pyrolysis oil from waste tyre, was used as raw material to prepare activated carbons (ACs) by KOH activation. KOH to TPC weight ratios (W) between 0.5 and 6, and activation temperatures from 600 to 800 °C, were used. An increase in W resulted in a more efficient development of surface area, microporosity and mesoporosity. Thus, ACs derived from TPC (TPC-ACs) with specific surface areas up to 814 m(2) g(-1) were obtained. TPC, TPC-ACs and a commercial AC (CAC) were tested for removing Tetracycline (TC) in aqueous phase, and systematic adsorption studies, including equilibrium, kinetics and thermodynamic aspects, were performed. Kinetics was well described by the pseudo-first order model for TPC, and by a pseudo second-order kinetic model for ACs. TC adsorption equilibrium data were also fitted by different isotherm models: Langmuir, Freundlich, Sips, Dubinin-Radushkevich, Dubinin-Astokov, Temkin, Redlich-Peterson, Radke-Prausnitz and Toth. The thermodynamic study confirmed that TC adsorption onto TPC-ACs is a spontaneous process. TC adsorption data obtained in the present study were compared with those reported in the literature, and differences were explained in terms of textural properties and surface functionalities. TPC-ACs had similar performances to those of commercial ACs, and might significantly improve the economic balance of the production of pyrolysis oil from waste tyres. PMID:26855221

  4. Estimation of surface heat flux for ablation and charring of thermal protection material

    Science.gov (United States)

    Qian, Wei-qi; He, Kai-feng; Zhou, Yu

    2016-07-01

    Ablation of the thermal protection material of the reentry hypersonic flight vehicle is a complex physical and chemical process. To estimate the surface heat flux from internal temperature measurement is much more complex than the conventional inverse heat conduction problem case. In the paper, by utilizing a two-layer pyrogeneration-plane ablation model to model the ablation and charring of the material, modifying the finite control volume method to suit for the numerical simulation of the heat conduction equation with variable-geometry, the CGM along with the associated adjoint problem is developed to estimate the surface heat flux. This estimation method is verified with a numerical example at first, the results show that the estimation method is feasible and robust. The larger is the measurement noise, the greater is the deviation of the estimated result from the exact value, and the measurement noise of ablated surface position has a significant and more direct influence on the estimated result of surface heat flux. Furthermore, the estimation method is used to analyze the experimental data of ablation of blunt Carbon-phenolic material Narmco4028 in an arc-heater. It is shown that the estimated surface heat flux agrees with the heating power value of the arc-heater, and the estimation method is basically effective and potential to treat the engineering heat conduction problem with ablation.

  5. Competitive biodegradation of dichlobenil and atrazine coexisting in soil amended with a char and citrate

    Energy Technology Data Exchange (ETDEWEB)

    Qiu Yuping; Pang Hui; Zhou Zunlong [College of Biological and Environmental Engineering, Zhejiang University of Technology, Hangzhou 310032 (China); Zhang Ping [Department of Civil Engineering, University of Minnesota, Minneapolis, MN 55455 (United States); Feng Yucheng [Department of Agronomy and Soils, Auburn University, Auburn, AL 36849 (United States); Sheng, G. Daniel, E-mail: dansheng@zjut.edu.c [College of Biological and Environmental Engineering, Zhejiang University of Technology, Hangzhou 310032 (China)

    2009-11-15

    The role of char nutrients in the biodegradation of coexisting dichlobenil and atrazine in a soil by their respective bacterial degraders, DDN and ADP, was evaluated. Under growing conditions, their degradation in soil extract was slow with <40% and <20% degraded within 64 h, respectively. The degradation in extracts and slurries of char-amended solids increased with increasing char content, due to nutritional stimulation on microbial activities. By supplementing soil extract with various major nutrients, the measured degradation demonstrated that P was the exclusive limiting nutrient. The reduction in the degradation of coexisting dichlobenil and atrazine resulted apparently from the competitive utilization of P by DDN and ADP. With a shorter lag phase, ADP commenced growing earlier than DDN with the advantage of utilizing P first in insufficient supply. This resulted in an inhibition on the growth of DDN and thus suppression on dichlobenil degradation. - Competitive utilization of char nutrients by bacterial degraders resulted in the preferential biodegradation of atrazine over dichlobenil in a soil containing a wheat-straw-derived char.

  6. Evaluación de la reducibilidad de un mineral de hierro usando char como reductor

    Directory of Open Access Journals (Sweden)

    Yenny Rubiela Hernández, Carlos Alberto Sandoval Fonseca, Claudia Inés Sánchez Buitrago

    2011-05-01

    Full Text Available Muestra los ensayos de  reduciblidad  realizados en un hornotipo Linder a un mineral de hierro del municipio de Ubalá(departamento de Cundinamarca, Colombia, usando comoreductor un char. Se  indican las características del mineralde  hierro  de Ubalá, de  los  carbones  empleados para  laproducción del char y de la caliza, así como los ensayos dereducibilidad. Para la caracterización de  las materias primasy del char, como producto  final, se aplicaron normas ASTM.En  la producción de  los char se utilizaron  los hornos decoquización  tipo Cerchar  y  tipo  colmena  de  la Uptc  enSamacá  (Boyacá. Los ensayos de reducibilidad se hicieronbajo  los mismos parámetros de operación utilizados concarbón como reductor, y los resultados obtenidos dejan verque el mineral de hierro de Ubalá es reducible en menorporcentaje con char. Sin embargo, por  los grandes beneficiospara el medioambiente que se obtienen trabajando con elchar, no se descarta  la posibilidad de utilizarlo como posiblesustituto del carbón en el proceso de reducción directa.

  7. Oxy-fuel combustion of millimeter-sized coal char: Particle temperatures and NO formation

    DEFF Research Database (Denmark)

    Brix, Jacob; Navascués, Leyre Gómez; Nielsen, Joachim Bachmann;

    2013-01-01

    In this work, differences in particle temperature and NO yield during char oxidation in O2/N2 and O2/CO2 atmospheres, respectively, have been examined. A laboratory scale fixed bed reactor, operated isothermally at 1073 K, was used for combustion of millimeter-sized lignite and bituminous coal char...... increased with mass loading, by as much as 700 K above the furnace set point. The formation of NO from lignite char was not influenced by the change from N2 to CO2 whereas the NO yield from bituminous coal char was considerably lower in O2/CO2 compared O2/N2. For both chars the conversion to NO decreased...... particles in 5–80 vol.% O2. Experiments were carried out with both single particles of different sizes (1.3–543 mg) and multiple particles (30–50 mg). Particle temperatures and structural changes were recorded by a Charged Coupled Device (CCD) camera during the experiments. The particle surface temperatures...

  8. Study of bio-oil and bio-char production from algae by slow pyrolysis

    International Nuclear Information System (INIS)

    This study examined bio-oil and bio-char fuel produced from Spirulina Sp. by slow pyrolysis. A thermogravimetric analyser (TGA) was used to investigate the pyrolytic characteristics and essential components of algae. It was found that the temperature for the maximum degradation, 322 °C, is lower than that of other biomass. With our fixed-bed reactor, 125 g of dried Spirulina Sp. algae was fed under a nitrogen atmosphere until the temperature reached a set temperature between 450 and 600 °C. It was found that the suitable temperature to obtain bio-char and bio-oil were at approximately 500 and 550 °C respectively. The bio-oil components were identified by a gas chromatography/mass spectrometry (GC–MS). The saturated functional carbon of the bio-oil was in a range of heavy naphtha, kerosene and diesel oil. The energy consumption ratio (ECR) of bio-oil and bio-char was calculated, and the net energy output was positive. The ECR had an average value of 0.49. -- Highlights: •Bio-oil and bio-char fuel produced from Spirulina Sp. by slow pyrolysis. •Suitable temperature to obtained bio-oil and bio-char were at about 550 and 500 °C. •Saturated functional carbon of bio-oil was heavy naphtha, kerosene, diesel oil. •ECR had an average value of 0.49

  9. Gasification of bio char from empty fruit bunch in a fluidized bed

    International Nuclear Information System (INIS)

    Full text: Bio char from empty fruit bunch was gasified in a fluidized bed reactor using compressed air as a gasifying agent. The experiment was conducted in the temperature ranges of 500-850 degree Celsius and the equivalence ratio, temperature and size of the feedstock was varied. A series of parameters such as gas yield, overall carbon conversion, gas quality, and composition, were measured as a function of temperature, equivalence ratio and temperature. Results obtained were compared to the actual values of coal and other gasification feedstock reveal that, bio char has the potential to replace coal as a gasification agent in power plants .Hydrogen gas from bio char was also optimized during the experiment. There is great potential of making Hydrogen from Bio char through thermo chemical gasification It was observed that it has a very great potential of being upgraded to Fischer Tropsh fuels. There is a great opportunity of using this char from empty fruit bunch as an alternative fuel in power plants and all the adverse effects of coal gasification can be counteracted. (author)

  10. CFD Simulation of Entrained Flow Gasification With Improved Devolatilization and Char Consumption Submodels

    KAUST Repository

    Kumar, Mayank

    2009-01-01

    In this work, we use a CFD package to model the operation of a coal gasifier with the objective of assessing the impact of devolatilization and char consumption models on the accuracy of the results. Devolatilization is modeled using the Chemical Percolation Devolitilization (CPD) model. The traditional CPD models predict the rate and the amount of volatiles released but not their species composition. We show that the knowledge of devolatilization rates is not sufficient for the accurate prediction of char consumption and a quantitative description of the devolatilization products, including the chemical composition of the tar, is needed. We incorporate experimental data on devolatilization products combined with modeling of the tar composition and reactions to improve the prediction of syngas compositions and carbon conversion. We also apply the shrinking core model and the random pore model to describe char consumption in the CFD simulations. Analysis of the results indicates distinct regimes of kinetic and diffusion control depending on the particle radius and injection conditions for both char oxidation and gasification reactions. The random pore model with Langmuir-Hinshelwood reaction kinetics are found to be better at predicting carbon conversion and exit syngas composition than the shrinking core model with Arrhenius kinetics. In addition, we gain qualitative and quantitative insights into the impact of the ash layer surrounding the char particle on the reaction rate. Copyright © 2010 by ASME.

  11. Tool Monitoring and Electronic Event Logging for Sheet Metal Forming Processes

    Directory of Open Access Journals (Sweden)

    Gerd Heiserich

    2010-06-01

    Full Text Available This contribution describes some innovative solutions regarding sensor systems for tool monitoring in the sheet metal industry. Autonomous and tamper-proof sensors, which are integrated in the forming tools, can detect and count the strokes carried out by a sheet metal forming press. Furthermore, an electronic event logger for documentary purposes and quality control was developed. Based on this technical solution, new business models such as leasing of sheet metal forming tools can be established for cooperation among enterprises. These models allow usage-based billing for the contractors, taking the effectively produced number of parts into account.

  12. Efficient Robust Optimization of Metal Forming Processes using a Sequential Metamodel Based Strategy

    NARCIS (Netherlands)

    Wiebenga, J.H.; Klaseboer, G.; Boogaard, van den A.H.; Chung, J.

    2011-01-01

    The coupling of Finite Element (FE) simulations to mathematical optimization techniques has contributed significantly to product improvements and cost reductions in the metal forming industries. The next challenge is to bridge the gap between deterministic optimization techniques and the industrial

  13. 棉秆和油菜秆热解焦炭的燃烧与吸附特性%Burning and adsorption characteristics of char obtained from pyrolysis of cotton stalk and rapeseed straw

    Institute of Scientific and Technical Information of China (English)

    刘标; 陈应泉; 孟海波; 姚宗路; 王贤华

    2014-01-01

    To study the characteristics of biochar products from biomass pyrolysis, cotton stalk and rapeseed straw were used as raw materials to prepare pyrolytic biochar samples under various temperatures (350, 550, 750, 950°C). The combustion characteristics, hydrating properties, CO2 adsorption characteristics, phenol adsorption characteristics and antioxidant abilities of different biochar samples (marked as CS350, CS550, CS750, CS950, RS350, RS550, RS750, RS950) were compared. A thermo gravimetric analyzer (STA409, NETZSCH) was used to investigate the combustion behavior of char. In the thermogravimetric experiment, approximately 10 mg of sample was heated in TG equipment at a heating rate of 20°C/min from room temperature to 900°C. TG-DTG tangent method was employed to determine the combustion characteristic indexes, including ignition temperature (Ti), burnout temperature (Tf) and the maximum mass loss rate (DTGmax). Results showed that theTi andTf value of char was increased with pyrolysis temperature increment, and CS550 and RS750 had better combustion characteristics due to their higher heating values and faster combustion rates, and they were appropriate for use as fuel char. Water absorption characteristics of char were conducted in a constant temperature and humidity box (Temperature: 30℃, Humidity: 90%), and an oven setting at 55℃ was used to test the dehydration characteristics of the chars. Gravimetric method was used to describe the water absorption and dehydration process of char and soil. The test results showed that CS350 and RS550 had higher water absorbing capacity and water retaining capacity than soil and other chars, and they were appropriate for biochar. CO2 adsorption characteristics of char were measured in an automatic adsorption equipment (Micromeritics, ASAP 2020, USA) at 273 K. Before the adsorption measurements, the sample was degassed at 150°C under a vacuum (pressure of 50 lmHg) for 10 h. The test results showed that the pyrolysis

  14. Explosive Processes on Cathode while Forming Nanosecond Pulsed Discharge of High Pressure

    Directory of Open Access Journals (Sweden)

    A. Hashimov

    2012-01-01

    Full Text Available The paper is devoted to research of cathode surfaces with different curvature radius (r = 1–8 mm while forming nanosecond pulsed discharge in dense air. Influence of field and air pressure heterogeneity rate in gas gap on size of micro-craters being formed on working cathode surface after pulsed effect has been shown in the paper. The paper reveals a maximum expansion of separate micro-crater size on cathode surface with small curvature radius.

  15. Material characterization and finite element simulations of aluminum alloy sheets during non-isothermal forming process

    Science.gov (United States)

    Zhang, Nan

    constructed by calculating the theoretical M-K model with Newton method and backtracking algorithm. The obtained FLDs are found to be instructive and will be applied in the post-processing of FE simulation for stamping so as to identify the critical area of failure. The developed constitutive model and modified yield function are implemented in the form of user defined subroutine (VUMAT) in ABAQUS/Explicit. An explicit stress integration algorithm has been selected for the stress integration with rate-depend viscoplasticity model at temperature higher than 150°. In the low temperature range, the Newton method and cutting plane algorithm are utilized to update the stress tensor with a classic elastoplastic constitutive model. To validate the VUMAT, a non-isothermal tensile testing has been performed with aids of infrared thermal camera and DIC. The heat transfer coefficients in FE model are calibrated with captured thermal images. With appropriate selection of mesh size and mass scaling factor, the punch load vs. displacement curve obtained from the simulation perfectly correlates the experimental result.

  16. Achieving process intensification form the application of a phenomena based synthesis, Design and intensification methodology

    DEFF Research Database (Denmark)

    Babi, Deenesh Kavi; Lutze, Philip; Woodley, John;

    Process Intensification/Process Systems Engineering. Process intensification (PI) is a means by which one can achieve a more efficient and sustainable chemical process. Major success in the area of PI has been achieved by Eastman chemicals [1] which in 1984 intensified the process...... of PI still faces challenges [2] because the identification and design of intensified processes is not simple [3]. Lutze et al [3] has developed a systematic PI synthesis/design method at the unit operations (Unit-Ops) level, where the search space is based on a knowledge-base of existing PI equipment...... for the manufacture of methyl acetate by replacing with one single reactive distillation column the multi-step process which consisted of one reactor, extractive distillation, liquid-liquid separation and azeotropic distillation. However, except for reactive distillation and dividing wall columns, the implementation...

  17. Development of carbon dioxide adsorbent from rice husk char

    Science.gov (United States)

    Abang, S.; Janaun, J.; Anisuzzaman, S. M.; Ikhwan, F. S.

    2016-06-01

    This study was mainly concerned about the development of carbon dioxide (CO2) adsorbent from rice husk (RH). Several chemical treatments were used to produce activated rice husk char (RHAC) from RH. Initially the RH was refluxed with 3M of sodium hydroxide (NaOH) solution, activation followed by using 0.5M of zinc chloride (ZnCl2) solution and finally acidic treatment by using 0.1M of hydrochloric acid (HCl). Then, the RHAC was functionalized by using 3-chloropropylamine hydrochloride (3-CPA) and noted as RHN. RHN samples were characterized with scanning electron microscopy (SEM), mercury intrusion porosimetry (MIP), fourier transform infrared spectroscopy (FTIR). Based on the SEM, the RHN sample had a large pore diameter compared to RH sample after being treated. Based on MIP data, the average pore diameter between RH and RHAC samples were increased significantly from 0.928 microns to 1.017 microns. The RHN sample also had higher total porosity (%) compared to RHAC and RH (58.45%, 47.82% and 45.57% respectively). The total specific surface area of the sample was much increasing from RHO to RHAC (29.17 m2/g and 62.94 m2/g respectively) and slightly being decreasing from RHAC to RHN (58.88 m2/g). FTIR result showed the present of weak band at 1587 cm-1 which demonstrating of the amine group present on the sample. The CO2 capture result showed that the decreasing of operating temperature can increase the breakthrough time of CO2 capture. On the contrary decreasing of CO2 gas flow rate can increase the breakthrough time of CO2 capture. The highest total amount of CO2 adsorbed was 25338.57 mg of CO2/g of RHN sample by using 100 mL/min of gas flow rate at 30oC. Based on adsorption isotherm analysis, the Freundlich isotherm was the best isotherm to describe the CO2 adsorption on the sample.

  18. The effect of pulverised coal’s devolatilisation conditions on char physical characteristics

    Directory of Open Access Journals (Sweden)

    Andrés Felipe Rojas González

    2010-04-01

    Full Text Available This study examined the effect of pulverised coal fuel devolatilisation conditions on char’s physical characteristics. A devolatilisation system was thus designed and built where three bituminous coals were devolatilised at three different times (100, 150 and 300 ms and at three temperatures (900°C, 1,000°C and 1,100°C. The resul- ting char was characterised regarding porosity, pore volume, surface area and particle size distribution. It was found that char porosity and pore volume increased with devolatilisation temperature and time. Devolatilisation operation conditions did not produce any effect on char’s specific surface area. However, char particle size was bigger than original coal size.

  19. The use of activated char for flue gas polishing in municipal and hazardous waste combustors

    Energy Technology Data Exchange (ETDEWEB)

    Hartenstein, H.U. [L & C Steinmueller GmbH, Gummersbach (Germany)

    1996-12-31

    During the late 1980`s and the early 1990`s legislation on emissions from waste combustors were tightened drastically. Also emission limits on new pollutants like dioxins and furans were introduced. Since the flue gas cleaning equipment commonly used before was not designed to meet these emission limits, new technologies had to be developed. Most of these new technologies rely on the use of activated carbon or char for the adsorption of the pollutants. Due to the fact that the amount of activated char used is directly proportional to the mass flow rate of pollutants entering the adsorber, the bulk part of the pollutants has been removed in the preceding gas cleaning stages. Thus the activated char adsorption reactor is employed as a flue gas polishing stage at the end of the APC-train.

  20. [Neuropsychological studies of the gnostic processes in children with various forms of infantile cerebral palsy].

    Science.gov (United States)

    Mamaĭchuk, I I

    1992-01-01

    Psychometric and neuropsychological studies were carried out in 182 patients with three forms of infantile cerebral paralysis (ICP). Of these, 112 children presented with spastic diplegia, 50 with hemiparetic diplegia, and 20 with hyperkinetic diplegia. The children's age ranged from 8 to 14 years. Depending on the form of ICP, the structural characteristics of intellect were defined as were specific features of the development of higher cortical functions depending on the localization of the underdevelopment of different brain areas. The classification of the structure of the disorders with the aid of the methods used makes it possible to have a differentiated approach to the medical and pedagogical correction of those patients. PMID:1333706