SIP threats detection system

OpenAIRE

Vozňák, Miroslav; Řezáč, Filip

2010-01-01

The paper deals with detection of threats in IP telephony, the authors developed a penetration testing system that is able to check up the level of protection from security threats in IP telephony. The SIP server is a key komponent of VoIP infrastructure and often becomes the aim of attacks and providers have to ensure the appropriate level of security. We have developed web-based penetration system which is able to check the SIP server if can face to the most common attacks.The d...

Integrating Usage Control with SIP-Based Communications

Directory of Open Access Journals (Sweden)

A. Lakas

2008-11-01

Full Text Available The Session Initiation Protocol (SIP is a signaling protocol used for establishing and maintaining communication sessions involving two or more participants. SIP was initially designed for voice over IP and multimedia conferencing, and then was extended to support other services such as instant messaging and presence management. Today, SIP is also adopted to be used with 3G wireless networks, thus it becomes an integral protocol for ubiquitous environment. SIP has various methods that support a variety of applications such as subscribing to a service, notification of an event, status update, and location and presence services. However, when it comes to security, the use of wireless and mobile communication technologies and the pervasive nature of this environment introduce higher risks to security than that of the old simple environment. In this paper, we introduce new architecture that implements a new type of access control called usage access control (UCON to control the access to the SIP-based communication at preconnection, during connection, and postconnection. This will enable prescribers of SIP services to control who can identify their locations to approve or disapprove their subsequent connections, and to also set some parameters to determine whether a certain communication can continue or should terminate.

Overload Control in a SIP Signaling Network

OpenAIRE

Masataka Ohta

2007-01-01

The Internet telephony employs a new type of Internet communication on which a mutual communication is realized by establishing sessions. Session Initiation Protocol (SIP) is used to establish sessions between end-users. For unreliable transmission (UDP), SIP message should be retransmitted when it is lost. The retransmissions increase a load of the SIP signaling network, and sometimes lead to performance degradation when a network is overloaded. The paper proposes an overload control for a S...

Clone of EPA Approved Regulations in the Texas SIP

Science.gov (United States)

changed name to EPA Approved Regulations in the Texas SIP, Add links to:Texas Read Me; Texas SIP History;Current/Previous SIP-Approved Regulations; Delete regulations--now in /node/191099, removed tables

Advisable alternative fuels for Mexico; Combustibles alternativos convenientes para Mexico

Energy Technology Data Exchange (ETDEWEB)

Aguilar Gonzalez, Jorge Luis [ICA Fluor (Mexico)

2007-07-15

The alternative fuels are born with the goal of not damaging the environment; biodiesel, electricity, ethanol, hydrogen, methanol, natural gas, LP gas, are the main alternative fuels. However, the biodiesel and bioetanol are the only completely renewable ones, this makes them ideal to be developed in Mexico, since the agricultural sector could be fortified, the technological independence be favored, improve the conservation of the oil resources and by all means not to affect the environment. On the other hand, also efficient cultivation techniques should be developed to guarantee the economy of the process. [Spanish] Los combustibles alternativos nacen con la meta de no danar el medio ambiente; el biodiesel, electricidad, etanol, hidrogeno, metanol, gas natural, gas LP, son los principales combustibles alternativos. No obstante, el biodiesel y el bioetanol son los unicos completamente renovables, esto los hace ideales para desarrollarse en Mexico, ya que se podria fortalecer el sector agricola, favorecer la independencia tecnologica, mejorar la administracion de los recursos petroleros y por supuesto no afectar al medio ambiente. Por otro lado tambien se tendrian que desarrollar tecnicas de cultivo eficientes para garantizar la economia del proceso.

TELESCOPE sipping - a proven fuel leak detection system

International Nuclear Information System (INIS)

Deleryd, R.; Collin, P.

1996-01-01

The advantages of the TELESCOPE sipping method are: For BWRs: clamp-on sipping nozzle, which attaches easily to the grapple of the telescope mast on the refuelling platform, but does not affect its operation; no heavy and large sipping bells have to be operated in the core with risk of damage, entangled hoses or lifting rods/wires; the sipping can also be performed for testing long time storaged fuel in the spent fuel pool. For PWRs: simple attachment of water suction hose or tube to the refuelling platform mast. (orig./DG)

NAT Traversing Solutions for SIP Applications

Directory of Open Access Journals (Sweden)

Huang Ya-Lin

2008-01-01

Full Text Available Abstract Session Initiation Protocol (SIP has been proposed for multimedia services and wide-area connectivity in smart home environments (SHEs. An important issue for SIP deployment in SHEs is network address translator (NAT traversing. SIP and Real-time Transport Protocol (RTP packets are delivered between an SHE (i.e., private IP network and Internet (i.e., a public IP network through an NAT function of a home gateway, and the NAT translates the IP/transport layer address and port number but leaves the application layer content unchanged. This results in inconsistency between the IP addresses/port numbers in the IP/transport layers and those in the SIP layer. To resolve this issue, we describe six solutions including static route, UPnP, STUN, ICE, ALG, and SBC. Then we compare these solutions in terms of smart home appliance (SHA modification, scope of NATs supported, multilayer NAT traversal, ease of configuration, security issue, and time complexities.

NAT Traversing Solutions for SIP Applications

Directory of Open Access Journals (Sweden)

Han-Chieh Chao

2008-05-01

Full Text Available Session Initiation Protocol (SIP has been proposed for multimedia services and wide-area connectivity in smart home environments (SHEs. An important issue for SIP deployment in SHEs is network address translator (NAT traversing. SIP and Real-time Transport Protocol (RTP packets are delivered between an SHE (i.e., private IP network and Internet (i.e., a public IP network through an NAT function of a home gateway, and the NAT translates the IP/transport layer address and port number but leaves the application layer content unchanged. This results in inconsistency between the IP addresses/port numbers in the IP/transport layers and those in the SIP layer. To resolve this issue, we describe six solutions including static route, UPnP, STUN, ICE, ALG, and SBC. Then we compare these solutions in terms of smart home appliance (SHA modification, scope of NATs supported, multilayer NAT traversal, ease of configuration, security issue, and time complexities.

Equipamento para medição do consumo de combustível em experimentos agrícolas

OpenAIRE

Gonzalez Maziero,José Valdemar; Corrêa,Ila Maria; Yanai,Kiyoshi; Menezes,João Floriano de

1992-01-01

É descrito e aferido (em condições de laboratório) um equipamento para medição de consumo de combustível para uso em experimentos com máquinas agrícolas. O medidor, construído com tubos-reservatórios de PVC, tubo de vidro graduado, tanque plástico de combustível e eletroválvulas (12 VCC), é ligado ao sistema de alimentação do trator com mangueiras de plástico de baixa pressão, controlando-se o fluxo de combustível mediante uma chave elétrica liga/desliga. Faz parte do conjunto um medidor de t...

Protocol d'inicialització de sessió SIP

OpenAIRE

Ibrahem Fernández, Samer

2006-01-01

Aquest projecte té com a finalitat estudiar el protocol SIP i desenvolupar una aplicació que l'implementi. Este proyecto tiene como finalidad estudiar el protocolo SIP y desarrollar una aplicación que la implemente The purpose of this project is to study the SIP protocol and develop an application that implements it.

High Load Diminution by Regulating Timers in SIP Servers

OpenAIRE

Montazerolghaem, Ahmadreza; Hosseini-Seno, Seyed-Amin; Yaghmaee, Mohammad Hossein; Budiarto, Rahmat

2014-01-01

To start voice, image, instant messaging, and generally multimedia communication, session communication must begin between two participants. SIP (session initiation protocol) that is an application layer control induces management and terminates this kind of sessions. As far as the independence of SIP from transport layer protocols is concerned, SIP messages can be transferred on a variety of transport layer protocols including TCP or UDP. Mechanism of Retransmission that is embedded in SIP c...

Measurements of SIP Signaling over 802.11b Links

NARCIS (Netherlands)

Hesselman, C.E.W.; Eertink, Henk; Eertink, E.H.; Widya, I.A.; Huizer, E.

The Session Initiation Protocol (SIP) is a popular application-level signaling protocol that is used for a wide variety of applications such as session control and mobility handling. In some of these applications, the exchange of SIP messages is time-critical, for instance when SIP is used to handle

Electrocatalizadores para pilas de combustible de membrana de intercambio protónico

OpenAIRE

Lázaro Elorri, María Jesús; Moliner Álvarez, Rafael; Calvillo Lamana, Laura; Pastor Ferrer, Elsa

2008-01-01

Electrocatalizadores para pilas de combustible de membrana de intercambio protónico. Procedimiento de obtención de un material de carbono mesoporoso (SMC) que comprende: la adición de sílice coloidal a un precursor polimérico de carbono; el curado térmico; el carbonizado del compuesto obtenido; lavado del compuesto carbonizado con ácido fluorhídrico (HF) o NaOH; y la oxidación del material lavado. Además la invención se refiere a un catalizador para pilas de combustibl...

{sup 124}I-L19-SIP for immuno-PET imaging of tumour vasculature and guidance of {sup 131}I-L19-SIP radioimmunotherapy

Energy Technology Data Exchange (ETDEWEB)

Tijink, Bernard M.; Perk, Lars R.; Budde, Marianne; Stigter-van Walsum, Marijke; Leemans, C.R. [VU University Medical Center, Department of Otolaryngology/Head and Neck Surgery, Amsterdam (Netherlands); Visser, Gerard W.M.; Kloet, Reina W. [VU University Medical Center, Nuclear Medicine and PET Research, Amsterdam (Netherlands); Dinkelborg, Ludger M. [Bayer Schering Pharma AG, Global Drug Discovery, Berlin (Germany); Neri, Dario [Swiss Federal Institute of Technology, Institute of Pharmaceutical Sciences, Zurich (Switzerland); Dongen, Guus A.M.S. van [VU University Medical Center, Department of Otolaryngology/Head and Neck Surgery, Amsterdam (Netherlands); VU University Medical Center, Nuclear Medicine and PET Research, Amsterdam (Netherlands)

2009-08-15

The human monoclonal antibody (MAb) fragment L19-SIP is directed against extra domain B (ED-B) of fibronectin, a marker of tumour angiogenesis. A clinical radioimmunotherapy (RIT) trial with {sup 131}I-L19-SIP was recently started. In the present study, after GMP production of {sup 124}I and efficient production of {sup 124}I-L19-SIP, we aimed to demonstrate the suitability of {sup 124}I-L19-SIP immuno-PET for imaging of angiogenesis at early-stage tumour development and as a scouting procedure prior to clinical {sup 131}I-L19-SIP RIT. {sup 124}I was produced in a GMP compliant way via {sup 124}Te(p,n){sup 124}I reaction and using a TERIMO trademark module for radioiodine separation. L19-SIP was radioiodinated by using a modified version of the IODO-GEN method. The biodistribution of coinjected {sup 124}I- and {sup 131}I-L19-SIP was compared in FaDu xenograft-bearing nude mice, while {sup 124}I PET images were obtained from mice with tumours of <50 to {proportional_to}700 mm{sup 3}. {sup 124}I was produced highly pure with an average yield of 15.4 {+-} 0.5 MBq/{mu}Ah, while separation yield was {proportional_to}90% efficient with <0.5% loss of TeO{sub 2}. Overall labelling efficiency, radiochemical purity and immunoreactive fraction were for {sup 124}I-L19-SIP: {proportional_to}80, 99.9 and >90%, respectively. Tumour uptake was 7.3{+-}2.1, 10.8{+-}1.5, 7.8{+-}1.4, 5.3{+-}0.6 and 3.1{+-}0.4%ID/g at 3, 6, 24, 48 and 72 h p.i., resulting in increased tumour to blood ratios ranging from 6.0 at 24 h to 45.9 at 72 h p.i. Fully concordant labelling and biodistribution results were obtained with {sup 124}I- and {sup 131}I-L19-SIP. Immuno-PET with {sup 124}I-L19-SIP using a high-resolution research tomograph PET scanner revealed clear delineation of the tumours as small as 50 mm{sup 3} and no adverse uptake in other organs. {sup 124}I-MAb conjugates for clinical immuno-PET can be efficiently produced. Immuno-PET with {sup 124}I-L19-SIP appeared qualified for sensitive

Two Stage Secure Dynamic Load Balancing Architecture for SIP Server Clusters

Directory of Open Access Journals (Sweden)

G. Vennila

2014-08-01

Full Text Available Session Initiation Protocol (SIP is a signaling protocol emerged with an aim to enhance the IP network capabilities in terms of complex service provision. SIP server scalability with load balancing has a greater concern due to the dramatic increase in SIP service demand. Load balancing of session method (request/response and security measures optimizes the SIP server to regulate of network traffic in Voice over Internet Protocol (VoIP. Establishing a honeywall prior to the load balancer significantly reduces SIP traffic and drops inbound malicious load. In this paper, we propose Active Least Call in SIP Server (ALC_Server algorithm fulfills objectives like congestion avoidance, improved response times, throughput, resource utilization, reducing server faults, scalability and protection of SIP call from DoS attacks. From the test bed, the proposed two-tier architecture demonstrates that the ALC_Server method dynamically controls the overload and provides robust security, uniform load distribution for SIP servers.

CacyBP/SIP promotes the proliferation of colon cancer cells.

Directory of Open Access Journals (Sweden)

Huihong Zhai

Full Text Available CacyBP/SIP is a component of the ubiquitin pathway and is overexpressed in several transformed tumor tissues, including colon cancer, which is one of the most common cancers worldwide. It is unknown whether CacyBP/SIP promotes the proliferation of colon cancer cells. This study examined the expression level, subcellular localization, and binding activity of CacyBP/SIP in human colon cancer cells in the presence and absence of the hormone gastrin. We found that CacyBP/SIP was expressed in a high percentage of colon cancer cells, but not in normal colonic surface epithelium. CacyBP/SIP promoted the cell proliferation of colon cancer cells under both basal and gastrin stimulated conditions as shown by knockdown studies. Gastrin stimulation triggered the translocation of CacyBP/SIP to the nucleus, and enhanced interaction between CacyBP/SIP and SKP1, a key component of ubiquitination pathway which further mediated the proteasome-dependent degradation of p27kip1 protein. The gastrin induced reduction in p27kip1 was prevented when cells were treated with the proteasome inhibitor MG132. These results suggest that CacyBP/SIP may be promoting growth of colon cancer cells by enhancing ubiquitin-mediated degradation of p27kip1.

Development of flameless combustion; Desarrollo de la combustion sin flama

Energy Technology Data Exchange (ETDEWEB)

Flores Sauceda, M. Leonardo; Cervantes de Gortari, Jaime Gonzalo [Universidad Nacional Autonoma de Mexico, Mexico, D.F. (Mexico)]. E-mail: 8344afc@prodigy.net.mx; jgonzalo@servidor.unam.mx

2010-11-15

The paper intends contribute to global warming mitigation joint effort that develops technologies to capture the CO{sub 2} produced by fossil fuels combustion and to reduce emission of other greenhouse gases like the NO{sub x}. After reviewing existing combustion bibliography is pointed out that (a) touches only partial aspects of the collective system composed by Combustion-Heat transfer process-Environment, whose interactions are our primary interest and (b) most specialists think there is not yet a clearly winning technology for CO{sub 2} capture and storage. In this paper the study of combustion is focused as integrated in the aforementioned collective system where application of flameless combustion, using oxidant preheated in heat regenerators and fluent gas recirculation into combustion chamber plus appropriated heat and mass balances, simultaneously results in energy saving and environmental impact reduction. [Spanish] El trabajo pretende contribuir al esfuerzo conjunto de mitigacion del calentamiento global que aporta tecnologias para capturar el CO{sub 2} producido por la combustion de combustibles fosiles y para disminuir la emision de otros gases invernadero como NOx. De revision bibliografica sobre combustion se concluye que (a) trata aspectos parciales del sistema compuesto por combustion-proceso de trasferencia de calor-ambiente, cuyas interacciones son nuestro principal interes (b) la mayoria de especialistas considera no hay todavia una tecnologia claramente superior a las demas para captura y almacenaje de CO{sub 2}. Se estudia la combustion como parte integrante del mencionado sistema conjunto, donde la aplicacion de combustion sin flama, empleando oxidante precalentado mediante regeneradores de calor y recirculacion de gases efluentes ademas de los balances de masa y energia adecuados, permite tener simultaneamente ahorros energeticos e impacto ambiental reducido.

Lateral load performance of SIP walls with full bearing

Science.gov (United States)

Boren Yeh; Tom Skaggs; Xiping Wang; Tom Williamson

2018-01-01

The purpose of this study was to develop test data needed to characterize lateral load performance of structural insulated panel (SIP) walls with full bearing (restrained). The research program involved structural testing of 29 full-size SIP walls (8 ft tall by 8 ft long) of various configurations that bracket a range of SIP wall configurations commonly used in the...

The Water SWITCH-ON Spatial Information Platform (SIP)

Science.gov (United States)

Sala Calero, J., Sr.; Boot, G., Sr.; Dihé, P., Sr.; Arheimer, B.

2017-12-01

The amount of hydrological open data is continually growing and providing opportunities to the scientific community. Although the existing data portals (GEOSS Portal, INSPIRE community geoportal and others) enable access to open data, many users still find browsing through them difficult. Moreover, the time spent on gathering and preparing data usually is more significant than the time spent on the experiment itself. Thus, any improvement on searching, understanding, accessing or using open data is greatly beneficial. The Spatial Information Platform (SIP) has been developed to tackle these issues within the SWITCH-ON European Commission funded FP7 project. The SIP has been designed as a set of tools based on open standards that provide to the user all the necessary functionalities as described in the Publish-Find-Bind (PFB) pattern. In other words, this means that the SIP helps users to locate relevant and suitable data for their experiments analysis, to access and transform it (filtering, extraction, selection, conversion, aggregation). Moreover, the SIP can be used to provide descriptive information about the data and to publish it so others can find and use it. The SIP is based on existing open data protocols such as the OGC/CSW, OGC/WMS, OpenDAP and open-source components like PostgreSQL/PostGIS, GeoServer and pyCSW. The SIP is divided in three main user interfaces: the BYOD (Browse your open dataset) web interface, the Expert GUI tool and the Upload Data and Metadata web interface. The BYOD HTML5 client is the main entry point for users that want to browse through open data in the SIP. The BYOD has a map interface based on Leaflet JavaScript libraries so that the users can search more efficiently. The web-based Open Data Registration Tool is a user-friendly upload and metadata description interface (geographical extent, license, DOI generation). The Expert GUI is a desktop application that provides full metadata editing capabilities for the metadata

SIP: A Web-Based Astronomical Image Processing Program

Science.gov (United States)

Simonetti, J. H.

1999-12-01

I have written an astronomical image processing and analysis program designed to run over the internet in a Java-compatible web browser. The program, Sky Image Processor (SIP), is accessible at the SIP webpage (http://www.phys.vt.edu/SIP). Since nothing is installed on the user's machine, there is no need to download upgrades; the latest version of the program is always instantly available. Furthermore, the Java programming language is designed to work on any computer platform (any machine and operating system). The program could be used with students in web-based instruction or in a computer laboratory setting; it may also be of use in some research or outreach applications. While SIP is similar to other image processing programs, it is unique in some important respects. For example, SIP can load images from the user's machine or from the Web. An instructor can put images on a web server for students to load and analyze on their own personal computer. Or, the instructor can inform the students of images to load from any other web server. Furthermore, since SIP was written with students in mind, the philosophy is to present the user with the most basic tools necessary to process and analyze astronomical images. Images can be combined (by addition, subtraction, multiplication, or division), multiplied by a constant, smoothed, cropped, flipped, rotated, and so on. Statistics can be gathered for pixels within a box drawn by the user. Basic tools are available for gathering data from an image which can be used for performing simple differential photometry, or astrometry. Therefore, students can learn how astronomical image processing works. Since SIP is not part of a commercial CCD camera package, the program is written to handle the most common denominator image file, the FITS format.

Design of a SIP device cooperation system on OSGi service platforms

Science.gov (United States)

Takayama, Youji; Koita, Takahiro; Sato, Kenya

2007-12-01

Home networks feature such various technologies as protocols, specifications, and middleware, including HTTP, UPnP, and Jini. A service platform is required to handle such technologies to enable them to cooperate with different devices. The OSGi service platform, which meets the requirements based on service-oriented architecture, is designed and standardized by OSGi Alliance and consists of two parts: one OSGi Framework and bundles. On the OSGi service platform, APIs are defined as services that can handle these technologies and are implemented in the bundle. By using the OSGi Framework with bundles, various technologies can cooperate with each other. On the other hand, in IP networks, Session Initiation Protocol (SIP) is often used in device cooperation services to resolve an IP address, control a session between two or more devices, and easily exchange the statuses of devices. However, since many existing devices do not correspond to SIP, it cannot be used for device cooperation services. A device that does not correspond to SIP is called an unSIP device. This paper proposes and implements a prototype system that enables unSIP devices to correspond to SIP. For unSIP devices, the proposed system provides device cooperation services with SIP.

A Survey of Open Source Products for Building a SIP Communication Platform

Directory of Open Access Journals (Sweden)

Pavel Segec

2011-01-01

Full Text Available The Session Initiation Protocol (SIP is a multimedia signalling protocol that has evolved into a widely adopted communication standard. The integration of SIP into existing IP networks has fostered IP networks becoming a convergence platform for both real-time and non-real-time multimedia communications. This converged platform integrates data, voice, video, presence, messaging, and conference services into a single network that offers new communication experiences for users. The open source community has contributed to SIP adoption through the development of open source software for both SIP clients and servers. In this paper, we provide a survey on open SIP systems that can be built using publically available software. We identify SIP features for service development and programming, services and applications of a SIP-converged platform, and the most important technologies supporting SIP functionalities. We propose an advanced converged IP communication platform that uses SIP for service delivery. The platform supports audio and video calls, along with media services such as audio conferences, voicemail, presence, and instant messaging. Using SIP Application Programming Interfaces (APIs, the platform allows the deployment of advanced integrated services. The platform is implemented with open source software. Architecture components run on standardized hardware with no need for special purpose investments.

Um modelo integrado econométrico+insumo-produto para previsão de longo prazo da demanda de combustíveis no Brasil

Directory of Open Access Journals (Sweden)

Flaviane Souza Santiago

2012-05-01

Full Text Available O artigo apresenta um modelo integrado de tipo econométrico+insumo-produto para previsões de longo prazo da demanda de combustíveis no Brasil. O modelo é baseado na integração por ligação de um modelo vetorial de correção de erros com um modelo de insumo-produto híbrido para a economia brasileira e permite fazer previsões anuais de consumo para quatro grupos de combustível: gasolina, óleo diesel, óleo combustível e álcool. No processo de desenvolvimento, tanto o modelo econométrico quanto o modelo integrado foram submetidos a testes de desempenho preditivo, com o último sendo calibrado para melhor performance, usando-se dados disponíveis para o período de 2004 a 2007. Posteriormente, o modelo integrado é usado para gerar previsões no período de 2008 a 2017. As previsões são baseadas em dois cenários alternativos, um prevendo duração curta, e o outro, duração longa para a atual crise econômica mundial. Os resultados obtidos indicam que, em ambos os casos, ocorrerá significativo aumento da demanda de combustíveis nos próximos 10 anos.

A methodology of SiP testing based on boundary scan

Science.gov (United States)

Qin, He; Quan, Haiyang; Han, Yifei; Zhu, Tianrui; Zheng, Tuo

2017-10-01

System in Package (SiP) play an important role in portable, aerospace and military electronic with the microminiaturization, light weight, high density, and high reliability. At present, SiP system test has encountered the problem on system complexity and malfunction location with the system scale exponentially increase. For SiP system, this paper proposed a testing methodology and testing process based on the boundary scan technology. Combining the character of SiP system and referencing the boundary scan theory of PCB circuit and embedded core test, the specific testing methodology and process has been proposed. The hardware requirement of the under test SiP system has been provided, and the hardware platform of the testing has been constructed. The testing methodology has the character of high test efficiency and accurate malfunction location.

DNA stable-isotope probing (DNA-SIP).

Science.gov (United States)

Dunford, Eric A; Neufeld, Josh D

2010-08-02

DNA stable-isotope probing (DNA-SIP) is a powerful technique for identifying active microorganisms that assimilate particular carbon substrates and nutrients into cellular biomass. As such, this cultivation-independent technique has been an important methodology for assigning metabolic function to the diverse communities inhabiting a wide range of terrestrial and aquatic environments. Following the incubation of an environmental sample with stable-isotope labelled compounds, extracted nucleic acid is subjected to density gradient ultracentrifugation and subsequent gradient fractionation to separate nucleic acids of differing densities. Purification of DNA from cesium chloride retrieves labelled and unlabelled DNA for subsequent molecular characterization (e.g. fingerprinting, microarrays, clone libraries, metagenomics). This JoVE video protocol provides visual step-by-step explanations of the protocol for density gradient ultracentrifugation, gradient fractionation and recovery of labelled DNA. The protocol also includes sample SIP data and highlights important tips and cautions that must be considered to ensure a successful DNA-SIP analysis.

Thermo-physical properties of reproducible Sip/Al composites

Institute of Scientific and Technical Information of China (English)

XIU Zi-yang; WU Gao-hui; SONG Mei-hui; ZHU De-zhi

2006-01-01

Three kinds of high volume fraction Sip/1199, Sip/4032 and Sip/4019 composites were fabricated by squeeze casting method. The results show that the clean Si/Al interfaces without interfacial reaction products can decrease the interfacial thermal resistance. The composites have a low coefficient of thermal expansion (7.5×10-6 ℃-1) and high thermal conductivity ranging from 126 to 157.9 W/(m ℃). With increasing temperature, the specific capacity and the average coefficient of thermal expansion increases monotonically, the thermal diffusivity and the thermal conductivity decrease gradually. The specific capacity, average coefficient of thermal expansion, thermal diffusivity and the thermal conductivity of the composites decrease gradually with increasing Si content.The thermal conductivities of composites were calculated by theoretical models. Both Maxwell model and P.G model consider the reinforcement as nearly-round particles, and the interface thermal resistance of Sip/Al composite calculated by EMA method is 0.01×10-6m2.℃/W

Impact of 50% Synthesized Iso-Paraffins (SIP) on F-76 Fuel Coalescence

Science.gov (United States)

2013-12-16

petroleum JP-5 and Synthesized Iso-Paraffins (SIP). SIP fuels are made from direct fermentation of sugar into olefinic hydrocarbons. The olefinic...manufactured scaled down filter/coalescer and separator to simulate the performance of a full-scale filter separator system. This test is designed to predict...5 and Synthesized Iso-Paraffins (SIP). SIP fuels are made from direct fermentation of sugar into olefinic hydrocarbons. The olefinic hydrocarbons

Heterologous protein secretion in Lactobacilli with modified pSIP vectors.

Directory of Open Access Journals (Sweden)

Ingrid Lea Karlskås

Full Text Available We describe new variants of the modular pSIP-vectors for inducible gene expression and protein secretion in lactobacilli. The basic functionality of the pSIP system was tested in Lactobacillus strains representing 14 species using pSIP411, which harbors the broad-host-range Lactococcus lactis SH71rep replicon and a β-glucuronidase encoding reporter gene. In 10 species, the inducible gene expression system was functional. Based on these results, three pSIP vectors with different signal peptides were modified by replacing their narrow-host-range L. plantarum 256rep replicon with SH71rep and transformed into strains of five different species of Lactobacillus. All recombinant strains secreted the target protein NucA, albeit with varying production levels and secretion efficiencies. The Lp_3050 derived signal peptide generally resulted in the highest levels of secreted NucA. These modified pSIP vectors are useful tools for engineering a wide variety of Lactobacillus species.

A Stepwise Approach to Developing Languages for SIP Telephony Service Creation

DEFF Research Database (Denmark)

Palix, Nicolas; Consel, Charles; Reveillere, Laurent

2007-01-01

Developing a SIP-based telephony service requires a programmer to have expertise in telephony rules and constraints, the SIP protocol, distributed systems, and a SIP API, which is often large and complex. These requirements make the development of telephony software an overwhelming challenge...... a scripting language dedicated to the development of telephony services. This approach enables critical properties of services to be guaranteed and captures expertise on the operational behavior of a service. We have applied this approach to developing the Session Processing Language (SPL) dedicated to SIP...

Influencia del porcentaje de mezcla del aceite de higuerilla en la obtención de combustible alternativo para motores diesel

OpenAIRE

Arnoldo Emilio Delgado; Willian Aperador Chaparro; Jorge Réne Silva Gonzalez

2011-01-01

En el presente artículo se describe el uso del aceite de higuerilla como combustible alternativo en motores diesel. Para este fi n, se obtiene biodiesel a partir de aceite de higuerilla mediante el proceso de transesterifi cación. Se prueban tres mezclas de biodiesel (B5%, B10% y B20%) en un motor diesel, para el cual se midieron los siguientes parámetros: la potencia, el consumo de combustible, la temperatura del motor, y los gases de combustión;las mezclas fueron caracterizadas mediante la ...

Stream Control Transmission Protocol as a Transport for SIP: a case study

Directory of Open Access Journals (Sweden)

Giuseppe De Marco

2004-06-01

Full Text Available The dominant signalling protocol both in future wireless and wired networks will be the Session Initiation Protocol (SIP, as pointed out in the 3G IP-based mobile networks specifications, entailing a fully Internet integrated network. The use of SIP in the IP Multimedia Subsytem (IMS of Release 5 involves the development of servers capable to handle a large number of call requests. The signaling traffic associated to such requests could explode, if an intelligent congestion control were not introduced. Stream Control Transmission Protocol (SCTP was born to support transport of SS7 signaling messages. However, many of the SCTP features are also useful for transport of SIP messages, as: congestion control mechanism, good separation among independent messages, multihoming. Indeed, adoption of SCTP as transport of SIP signaling might prove useful in some situations where usual transport protocols, like TCP and UDP, suffer performance degradation. In this paper, we analyse the general framework wherein SIP operates and we discuss the benefits of using SCTP as a transport for SIP, toward fair sharing of network resources. This study is carried on in the context of the implementation of an high-performance SIP Proxy Server. We also present some preliminar results of an implementation of SIP over SCTP/UDP in a real LAN environment.

MÉTODOS PARA CARACTERIZAR COMBUSTIBLES LÍQUIDOS Y GASEOSOS OBTENIDOS DE LLANTAS EN DESUSO A TRAVÉS DE LAS NORMAS ASTM.

Directory of Open Access Journals (Sweden)

JAIME ALEJANDRO OSPINA

2011-12-01

Full Text Available Este artículo muestra la importancia de la caracterización de la energía de combustibles líquidos y gaseosos obtenidos del conocido tratamiento térmico de pirolisis a través de un microondas. La caracterización de estos combustibles tomará en cuenta los estándares técnicos tales como ASTM D3452 – 93 para la cromatografía de gases (GC, ASTM D2549 para cromatografía de gas/ espectrometría de masa (GC/MS y ASTM D6370 -99 para termogravimetría en el análisis de la composición de llantas.También muestra que estos combustibles y gases de pirolisis tiene una alta valor calorífico de 42 MJ / Kg y un contenido de azufre entre 0.8 y 1.65 Wt%, dependiendo en el tipo de llanta y las condiciones del proceso.

SIP Signaling Implementations and Performance Enhancement over MANET: A Survey

OpenAIRE

Alshamrani, M; Cruickshank, Haitham; Sun, Zhili; Ansa, G; Alshahwan, F

2016-01-01

The implementation of the Session Initiation Protocol (SIP)-based Voice over Internet Protocol (VoIP) and multimedia over MANET is still a challenging issue. Many routing factors affect the performance of SIP signaling and the voice Quality of Service (QoS). Node mobility in MANET causes dynamic changes to route calculations, topology, hop numbers, and the connectivity status between the correspondent nodes. SIP-based VoIP depends on the caller’s registration, call initiation, and call termin...

Diesel oil combustion in fluidized bed; Combustion de aceite diesel en lecho fluidizado

Energy Technology Data Exchange (ETDEWEB)

Rodriguez Cazares, Mario [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

1992-07-01

The effect of the fluidized bed depth in the combustion in burning diesel oil in a fluidized bed, was analyzed. A self sustained combustion was achieved injecting the oil with an injector that utilized a principle similar to an automobile carburetor venturi. Three different depths were studied and it was found that the deeper the bed, the greater the combustion efficiency. Combustion efficiencies were attained from 82% for a 100mm bed depth, up to 96% for a 200mm bed depth. The diminution in the efficiency was mainly attributed to unburned hydrocarbons and to the carbon carried over, which was observed in the black smoke at the stack outlet. Other phenomena registered were the temperature gradient between the lower part of the bed and the upper part, caused by the fluidization velocity; additionally it was observed that the air employed for the oil injection (carbureting air) is the most important parameter to attain a complete combustion. [Espanol] Se analizo el efecto de la profundidad del lecho en la combustion al quemar aceite diesel en un lecho fluidizado experimental. Se logro combustion autosostenida inyectando el aceite con un inyector que utilizo un principio similar al venturi del carburador de automovil. Se estudiaron tres diferentes profundidades del lecho y se encontro que a mayor profundidad del lecho, mayor eficiencia de la combustion. Se lograron eficiencias de la combustion desde 82% para el lecho de 100 mm de profundidad hasta 96% para el de 200 mm. La disminucion de la eficiencia se atribuyo, principalmente, a los hidrocarburos no quemados y al carbon arrastrado, lo cual se observo en el humo negro a la salida de la chimenea. Otros fenomenos registrados fueron el gradiente de temperatura entre la parte baja del lecho y la parte superior causado por la velocidad de fluidizacion; ademas, se observo que el aire utilizado para inyectar el aceite (aire de carburacion) es el parametro mas importante para lograr una combustion completa.

para celdas de combustible de etanol

Directory of Open Access Journals (Sweden)

CARLOS MONSALVE GIL

2008-01-01

Full Text Available En este trabajo se elaboraron dos membranas nanocompuestas de Nafion®- TiO2 con 2 y 4% del cerámico por el método del “recasting”. El análisis de composición del microscopio de barrido electrónico (SEMEDS mostró una estructura de dos capas, una enriquecida en cerámico y otra con menos cantidad, pero con dispersión uniforme. Se midió la velocidad de permeación de etanol y la absorción de solventes en estas membranas a diferentes temperaturas y concentraciones y los resultados fueron comparados con los obtenidos para la membrana de Nafion® sin modificar. Los resultados experimentales mostraron un incremento de la permeación y de la absorción de solvente con la concentración de etanol y la temperatura. La absorción de agua también mostró un incremento en las membranas compuestas lo cual puede permitir operar a mayores temperaturas y menores humedades relativas y aumentar el desempeño de la celda de combustible.

The SIP express router: An open source SIP platform: Presentation held at EVOLUTE - seamlEss multimedia serVices Over alL IP-based infrastrUcTurEs Workshop, 10. November 2003, Guildford, UK

OpenAIRE

Rebahi, Y.; Sisalem, D.; Kuthan, J.; Pelinescu-Oncicul, A.; Iancu, B.; Janak, J.; Mierla, D.C.

2003-01-01

The session initiation protocol (SIP) is constantly gaining in popularity and acceptance as the signaling protocol for next generation multimedia communication. This paper describes a scalable and reliable open source SIP platform called the SIP Express Router (SER). SER does not only support basic SIP features but also advanced features such as messaging and presence, translation between SIP and SMS or Jabber as well as full featured application programming interfaces. In this paper we will ...

Deployment of SIP in MANET: challenges and circumvention

Directory of Open Access Journals (Sweden)

Abdelhamid Salma R.

2017-01-01

Full Text Available The immense growth in wireless network applications has encouraged the researchers to enhance and propose new approaches that facilitate the deployment of the widely used services, protocols, and applications of the wired networking area in the wireless networks. Among which, the Session Initiation Protocol (SIP is a signaling protocol that allows the establishment of multimedia sessions and calls between different parties. SIP functionality totally depends on a centralized infrastructure, and complexity arises when deploying such a protocol in a special type of wireless networks, namely Mobile Ad-hoc Networks (MANET, due to the absence of a centralized infrastructure, and the dynamic topology of the later. This paper highlights the the challenges arising when deploying SIP in MANETs and presents an overview of different proposed approaches to overcome these challenges.

Testing Dialog-Verification of SIP Phones with Single-Message Denial-of-Service Attacks

Science.gov (United States)

Seedorf, Jan; Beckers, Kristian; Huici, Felipe

The Session Initiation Protocol (SIP) is widely used for signaling in multimedia communications. However, many SIP implementations are still in their infancy and vulnerable to malicious messages. We investigate flaws in the SIP implementations of eight phones, showing that the deficient verification of SIP dialogs further aggravates the problem by making it easier for attacks to succeed. Our results show that the majority of the phones we tested are susceptible to these attacks.

Improvement of the Response Time in an Open Source Audioconference Architecture Based on SIP Multicast Implemented with JainSIP, JainSDP and JGAP Libraries

Directory of Open Access Journals (Sweden)

Carlos M. Moreno

2014-06-01

Full Text Available Group services like the audioconference require a minimum level of quality of service for multicast sessions. This work proposes a new overlay multicast architecture based on SIP extensions and a genetic algorithm. The architecture consists of a SIP Extender client (SE, a Multicast Gateway Agent (MGA and a Multicast Manager (MM. The SE receives information about the most adequate MGA for it determined by a genetic algorithm inside the MM, then connects the chosen MGA and maintains connection with the MM itself. The genetic algorithm is implemented with JGAP(Java Genetic Algorithm Package libraries. The SE and MGA are programmed with JainSIP and JainSDP libraries which contain Java structures associated with the SIP protocol and session description. Some experiments over UTP wired and WiFi IEEE802.11n network were performed. Partial results with static and dynamic MGA selection show that, if we compare the joining and leaving time measured inside a station containing SE client programmed with JainSIP and JainSDP libraries versus SJphone proprietary client, the software engineering may have more influence than the medium access method in the response time for a potential group member. Even more, the genetic algorithm at the MM minimizes the response time at great scale.

Creep Behavior of Structural Insulated Panels (SIPS): Results from a Pilot Study

Science.gov (United States)

Dwight McDonald; Marshall Begel; C. Adam Senalik; Robert Ross; Thomas D. Skaggs; Borjen Yeh; Thomas Williamson

2014-01-01

Structural insulated panels (SIPs) have been recognized as construction materials in the International Residential Code (IRC) since 2009. Although most SIPs are used in wall applications, they can also be used as roof or floor panels that are subjected to long-term transverse loading, for which SIP creep performance may be critical in design. However, limited...

A lightweight privacy preserving authenticated key agreement protocol for SIP-based VoIP

OpenAIRE

Zhang, Liping; Tang, Shanyu; Zhu, Shaohui

2016-01-01

Session Initiation Protocol (SIP) is an essential part of most Voice over Internet Protocol (VoIP) architecture. Although SIP provides attractive features, it is exposed to various security threats, and so an efficient and secure authentication scheme is sought to enhance the security of SIP. Several attempts have been made to address the tradeoff problem between security and efficiency, but designing a successful authenticated key agreement protocol for SIP is still a challenging task from t...

Nationwide SIP Telephony Network Design to Prevent Congestion Caused by Disaster

Science.gov (United States)

Satoh, Daisuke; Ashitagawa, Kyoko

We present a session initiation protocol (SIP) network design for a voice-over-IP network to prevent congestion caused by people calling friends and family after a disaster. The design increases the capacity of SIP servers in a network by using all of the SIP servers equally. It takes advantage of the fact that equipment for voice data packets is different from equipment for signaling packets in SIP networks. Furthermore, the design achieves simple routing on the basis of telephone numbers. We evaluated the performance of our design in preventing congestion through simulation. We showed that the proposed design has roughly 20 times more capacity, which is 57 times the normal load, than the conventional design if a disaster were to occur in Niigata Prefecture struck by the Chuetsu earthquake in 2004.

Gest-sip1 experiments and post-test calculations with the relap5 code

International Nuclear Information System (INIS)

Achilli, A.; Cattadori, G.; Ferri, R.; Gandolfi, S.; Bianchi, F.; Meloni, P.

2001-01-01

The SIP-1 apparatus (Sistema di Iniezione Passiva) was conceived, designed, numerically simulated and tested by the SIET company as an innovative depressurization and make-up device for the New Generation LWRs. In particular it is suitable to cope with those accidents where pressure in the circuit must be dumped to allow low pressure injection systems to intervene. The main peculiarity of SIP-1 is the capability of de-pressurizing a system by cold water injection, rather than by discharging mass to the outlet, as in the common depressurization systems. ENEA sponsored all the research activity, starting from the SIP-1 design, its numerical simulation with the Relap5 code, the realisation of an experimental facility up to the test execution and post-test calculations. An experimental campaign on the GEST-SIP1 facility was performed in July 2000. The facility is mainly constituted by a U-tube Steam Generator which a proper model of SIP-1 apparatus is connected to. A series of Small Break LOCAs was simulated by varying the break size and different steady conditions were investigated to verify the stability of SIP-1, the lack of unexpected interventions and the actuation modalities. This paper deals with the description of the GEST-SIP1 experimental facility, the SIP-1 operating principles, the most meaningful results of the tests and the capability of the Relap5 code in reproducing phenomena and events. (author)

Overexpressed CacyBP/SIP leads to the suppression of growth in renal cell carcinoma

International Nuclear Information System (INIS)

Sun, Shiren; Ning, Xiaoxuan; Liu, Jie; Liu, Lili; Chen, Yu; Han, Shuang; Zhang, Yanqi; Liang, Jie; Wu, Kaichun; Fan, Daiming

2007-01-01

Calcyclin-binding protein/Siah-1-interacting protein (CacyBP/SIP), a target protein of S100, has been identified as a component of a novel ubiquitinylation complex leading to β-catenin degradation, which was found to be related to the malignant phenotypes of gastric cancer. However, the roles of CacyBP/SIP in renal cell carcinoma still remain unclear. In the present study, we had analyzed the expression of the CacyBP/SIP protein in human renal cancer cells and clinical tissue samples. The possible roles of CacyBP/SIP in regulating the malignant phenotype of renal cancer cells were also investigated. The results demonstrated that the expression of CacyBP/SIP was markedly down-regulated in renal cell carcinoma tissues and cell lines. Ectopic overexpression of CacyBP/SIP in A498 cells inhibited the proliferation of this cell and delayed cell cycle progression significantly, which might be related to the down-regulation of Cyclin D1 through reducing β-catenin protein. CacyBP/SIP also suppressed colony formation in soft agar and its tumorigenicity in nude mice. Taken together, our work showed that CacyBP/SIP, as a novel down-regulated gene in renal cell carcinoma, suppressed proliferation and tumorigenesis of renal cancer cells

A combined wet/dry sipping cell for investigating failed triga fuel elements

International Nuclear Information System (INIS)

Boeck, H.; Gallhammer, H.; Hammer, J.; Israr, M.

1987-08-01

A sipping cell to detect failed triga fuel has been designed and constructed at the Atominstitut. The cell allows both wet- and dry sipping of one single standard triga fuel element. In the dry sipping method the fuel element may be electrically heated up to a maximum temperature of about 300 0 C to allow the detection of temperature dependent fission product release from the fuel element. 20 figs., 1 tab. (Author)

Decrease of noxious emissions in the residual fuel oil combustion; Disminucion de emisiones nocivas en la combustion de aceite combustible residual

Energy Technology Data Exchange (ETDEWEB)

Mandoki W, Jorge [Econergia S. de R. L. de C. V. Mexico, D. F. (Mexico)

1994-12-31

achieved. [Espanol] La combustion de aceite combustible residual emite sustancias nocivas como particulas carbonaceas, oxidos de nitrogeno y trioxido de azufre, a niveles inadmisibles. Agua emulsionada en el combustible reduce sustancialmente dichas emisiones, lograndose ademas, en la mayoria de los casos, un ahorro neto en el consumo de combustible. Se muestran los efectos beneficos de quemar el aceite combustible residual en forma de emulsion, asi como el metodo para producir una emulsion adecuada. La tecnologia del combustible emulsionado ofrece una opcion de bajo costo para reducir la contaminacion atmosferica. La calidad del aceite combustible residual ha estado declinando durante las ultimas decadas debido: 1. Al aumento en la produccion de petroleos crudos pesados generalmente con mayor contenido de asfaltenos y de azufre. 2. A menor disponibilidad de residuos de la destilacion al vacio debido a su conversion a productos de mayor valor. 3. A procesos de conversion mas intensivos, como cracking catalitico, {sup v}isbreaking{sup ,} etc., que aumentan la concentracion de asfaltenos en los fondos, ocasionando problemas de inestabilidad. 4. Al aumento en el contenido de vanadio y de otros metales a medida que aumenta la concentracion de asfaltenos. El uso de aceite combustible emulsionado proporciona un medio eficaz y economico para reducir sustancialmente las emisiones nocivas a la atmosfera. La emulsion contiene particulas de agua de un diametro entre 2 y 20 micras, dispersadas uniformemente dentro del aceite combustible, en una proporcion generalmente enter 5 y 10%; ademas contiene un agente tensioactivo para asegurar una emulsion estable, capaz de resistir los esfuerzos cortantes del sistema de bombeo y distribucion. Cuando las gotas de aceite combustible atomizado llegan a la camara de combustion, el agua esmulsionada en ellas se convierte instantaneamente en vapor de alta presion, ocasionando una violenta atomizacion secundaria. El efecto de esta atomizacion

On SIP Session setup delay for VoIP services over correlated fading channels

DEFF Research Database (Denmark)

Fathi, Hanane; Chakraborty, Shyam S.; Prasad, Ramjee

2006-01-01

In this paper, the session setup delay of the session initiation protocol (SIP) is studied. The transmissions on both the forward and reverse channel are assumed to experience Markovian errors. The session setup delay is evaluated for different transport protocols, and with the use of the radio...... link protocol (RLP). An adaptive retransmission timer is used to optimize SIP performances. Using numerical results, we find that SIP over user datagram protocol (UDP) instead of transport control protocol (TCP) can make the session setup up to 30% shorter. Also, RLP drastically reduces the session...... setup delay down to 4 to 5 s, even in environments with high frame error rates (10%) and significant correlation in the fading process (fDT=0.02). SIP is compared with its competitor H.323. SIP session setup delay with compressed messages outperforms H.323 session setup delay....

78 FR 21281 - Approval and Promulgation of Implementation Plans; State of Missouri; Infrastructure SIP...

Science.gov (United States)

2013-04-10

... existing SIP provisions for this purpose. Instead, EPA is only evaluating whether the state's SIP has basic...) requires SIPs to include provisions to provide for establishment and operation of ambient air quality..., restaurants, etc. triggering GHG PSD requirements. On December 23, 2010, EPA promulgated a subsequent series...

Optimización de la medida de conductividad en membranas poliméricas para pilas de combustible

OpenAIRE

Espeso González, Iván

2016-01-01

El objetivo de este Trabajo de Fin de Grado se centra en la medida de conductividad iónica de membranas poliméricas de intercambio iónico en diferentes celdas de conductividad para poder optimizar este tipo de medidas y evaluar las ventajas e inconvenientes que presenta cada una de las celdas de conductividad utilizadas para poder ser utilizadas con otro tipo de membranas poliméricas utilizadas también como electrolitos sólidos en pilas de combustible. Se han utilizado co...

A Secured Authentication Protocol for SIP Using Elliptic Curves Cryptography

Science.gov (United States)

Chen, Tien-Ho; Yeh, Hsiu-Lien; Liu, Pin-Chuan; Hsiang, Han-Chen; Shih, Wei-Kuan

Session initiation protocol (SIP) is a technology regularly performed in Internet Telephony, and Hyper Text Transport Protocol (HTTP) as digest authentication is one of the major methods for SIP authentication mechanism. In 2005, Yang et al. pointed out that HTTP could not resist server spoofing attack and off-line guessing attack and proposed a secret authentication with Diffie-Hellman concept. In 2009, Tsai proposed a nonce based authentication protocol for SIP. In this paper, we demonstrate that their protocol could not resist the password guessing attack and insider attack. Furthermore, we propose an ECC-based authentication mechanism to solve their issues and present security analysis of our protocol to show that ours is suitable for applications with higher security requirement.

Consumo de combustível e emissões de poluentes em um motor Diesel convertido a etanol para geração térmica de energia elétrica

Directory of Open Access Journals (Sweden)

Vinícius Rückert Roso

2016-03-01

Full Text Available Nos esforços globais para a minimização nas emissões de gases do efeito estufa e redução da pegada de carbono, combustíveis renováveis têm sido extensivamente utilizados em substituição aos combustíveis fósseis nos motores de combustão interna. Particularmente para geração de energia elétrica local, motores diesel são os mais utilizados devido à elevada eficiência térmica e a robustez, se comparado a motores de ignição por centelha. Entretanto, estes sistemas apresentam elevados níveis de emissões de óxido de nitrogênio (NOx e material particulado, trazendo sérias consequências para o meio ambiente. Assim, esta pesquisa combina simulação computacional e resultados experimentais da conversão de um motor diesel para a operação com etanol, sendo sua utilização na geração de energia elétrica. Como este combustível renovável é largamente produzido no Brasil utilizando a cana-de-açúcar, acaba por possuir seu custo reduzido em especial próximo à produtores e refinarias. Dados experimentais foram utilizados na validação do modelo computacional unidimensional desenvolvido para a conversão, onde resultados foram analisados para a comparação de ambos combustíveis. Análises econômicas para diferentes condições de carga forneceram informações de custos operacionais em locais próximos às fontes de produção de etanol. Os resultados apontam as vantagens no uso do combustível renovável para a geração de energia elétrica, como o custo reduzido e a menor emissão de NOx ao longo de toda a gama de operação.

Minimizing SIP Session Re-Setup Delay over Wireless Link in 3G Handover Scenarios

Directory of Open Access Journals (Sweden)

Moon Bongkyo

2010-01-01

Full Text Available The delay in transmitting SIP messages over the wireless link for session resetup at handover is still major bottleneck for interactive multimedia service. In this paper, a proxy agent-based scheme is proposed to minimize the SIP session setup delay over a wireless link in 3G inter-subnet handover scenarios. This scheme is based on the two characteristics. One is that the major factor of SIP session re-setup delay is generally caused by the retransmissions in the unreliable wireless links, and the other is that most of the fields in request messages as well as response messages are duplicated when a set of SIP messages are exchanged during session re-setup procedure. In this scheme, no change is required in the SIP message processing except for the proxy agents in both BS and MH.

Comparison of artificial intelligence classifiers for SIP attack data

Science.gov (United States)

Safarik, Jakub; Slachta, Jiri

2016-05-01

Honeypot application is a source of valuable data about attacks on the network. We run several SIP honeypots in various computer networks, which are separated geographically and logically. Each honeypot runs on public IP address and uses standard SIP PBX ports. All information gathered via honeypot is periodically sent to the centralized server. This server classifies all attack data by neural network algorithm. The paper describes optimizations of a neural network classifier, which lower the classification error. The article contains the comparison of two neural network algorithm used for the classification of validation data. The first is the original implementation of the neural network described in recent work; the second neural network uses further optimizations like input normalization or cross-entropy cost function. We also use other implementations of neural networks and machine learning classification algorithms. The comparison test their capabilities on validation data to find the optimal classifier. The article result shows promise for further development of an accurate SIP attack classification engine.

76 FR 28437 - Disease, Disability, and Injury Prevention and Control Special Interest Projects (SIPs): Initial...

Science.gov (United States)

2011-05-17

... Preventive Services for Older Adults SIP11-045, and Measuring Impact of Multi-Component Interventions to Prevent Older Adult Falls and Assessing Sustainability and Scalability, SIP 11-046, Panel D,'' initial... SIP11-045, and Measuring Impact of Multi- Component Interventions to Prevent Older Adult Falls and...

CacyBP/SIP binds ERK1/2 and affects transcriptional activity of Elk-1

International Nuclear Information System (INIS)

Kilanczyk, Ewa; Filipek, Slawomir; Jastrzebska, Beata; Filipek, Anna

2009-01-01

In this work we showed for the first time that mouse CacyBP/SIP interacts with extracellular signal regulated kinases 1 and 2 (ERK1/2). We also established that a calcium binding protein, S100A6, competes for this interaction. Moreover, the E217K mutant of CacyBP/SIP does not bind significantly to ERK1/2 although it retains the ability to interact with S100A6. Molecular modeling shows that the E217K mutation in the 189-219 CacyBP/SIP fragment markedly changes its electrostatic potential, suggesting that the binding with ERK1/2 might have an electrostatic character. We also demonstrate that CacyBP/SIP-ERK1/2 interaction inhibits phosphorylation of the Elk-1 transcription factor in vitro and in the nuclear fraction of NB2a cells. Altogether, our data suggest that the binding of CacyBP/SIP with ERK1/2 might regulate Elk-1 phosphorylation/transcriptional activity and that S100A6 might further modulate this effect via Ca 2+ -dependent interaction with CacyBP/SIP and competition with ERK1/2.

Spectral induced polarization (SIP) response of mine tailings.

Science.gov (United States)

Placencia-Gómez, Edmundo; Parviainen, Annika; Slater, Lee; Leveinen, Jussi

2015-02-01

Mine tailings impoundments are a source of leachates known as acid mine drainage (AMD) which can pose a contamination risk for surrounding surface and groundwater. Methodologies which can help management of this environmental issue are needed. We carried out a laboratory study of the spectral induced polarization (SIP) response of tailings from the Haveri Au-Cu mine, SW Finland. The primary objectives were, (1) to determine possible correlations between SIP parameters and textural properties associated with oxidative-weathering mechanisms, mineralogical composition and metallic content, and (2) to evaluate the effects of the pore water chemistry on SIP parameters associated with redox-inactive and redox-active electrolytes varying in molar concentration, conductivity and pH. The Haveri tailings exhibit well defined relaxation spectra between 100 and 10,000Hz. The relaxation magnitudes are governed by the in-situ oxidative-weathering conditions on sulphide mineral surfaces contained in the tailings, and decrease with the oxidation degree. The oxidation-driven textural variation in the tailings results in changes to the frequency peak of the phase angle, the imaginary conductivity and chargeability, when plotted versus the pore water conductivity. In contrast, the real and the formation electrical conductivity components show a single linear dependence on the pore water conductivity. The increase of the pore water conductivity (dominated by the increase of ions concentration in solution) along with a transition to acidic conditions shifts the polarization peak towards higher frequencies. These findings show the unique sensitivity of the SIP method to potentially discriminate AMD discharges from reactive oxidation zones in tailings, suggesting a significant advantage for monitoring threatened aquifers. Copyright © 2014 Elsevier B.V. All rights reserved.

The SHIP: A SIP to HTTP Interaction Protocol

Science.gov (United States)

Zeiß, Joachim; Gabner, Rene; Bessler, Sandford; Happenhofer, Marco

IMS is capable of providing a wide range of services. As a result, terminal software becomes more and more complex to deliver network intelligence to user applications. Currently mobile terminal software needs to be permanently updated so that the latest network services and functionality can be delivered to the user. In the Internet, browser based user interfaces assure that an interface is made available to the user which offers the latest services in the net immediately. Our approach combines the benefits of the Session Initiation Protocol (SIP) and those of the HTTP protocol to bring the same type of user interfacing to IMS. SIP (IMS) realizes authentication, session management, charging and Quality of Service (QoS), HTTP provides access to Internet services and allows the user interface of an application to run on a mobile terminal while processing and orchestration is done on the server. A SHIP enabled IMS client only needs to handle data transport and session management via SIP, HTTP and RTP and render streaming media, HTML and Javascript. SHIP allows new kinds of applications, which combine audio, video and data within a single multimedia session.

Comparison of H.323 and SIP for IP telephony signaling

Science.gov (United States)

Dalgic, Ismail; Fang, Hanlin

1999-11-01

Two standards currently compete for the dominance of IP telephony signaling: the H.323 protocol suite by ITU-T, and the Session Initiation Protocol (SIP) by IETF. Both of these signaling protocols provide mechanisms for call establishment and teardown, call control and supplementary services, and capability exchange. We investigate and compare these two protocols in terms of Functionality, Quality of Service (QoS), Scalability, Flexibility, Interoperability, and Ease of Implementation. For fairness of comparison, we consider similar scenarios for both protocols. In particular, we focus on scenarios that involve a gatekeeper for H.323, and a Proxy/Redirect server for SIP. The reason is that medium-to-large IP Telephony systems are not manageable without a gatekeeper or proxy server. We consider all three versions of H.323. In terms of functionality and services that can be supported, H.323 version 2 and SIP are very similar. However, supplementary services in H.323 are more rigorously defined, and therefore fewer interoperability issues are expected among its implementations. Furthermore, H.323 has taken more steps to ensure compatibility among its different versions, and to interoperate with PSTN. The two protocols are comparable in their QoS support [similar call setup delays, no support for resource reservation or class of service (CoS) setting], but H.323 version 3 will allow signaling of the requested CoS. SIP's primary advantages are (1) flexibility to add new features, and (2) relative ease of implementation and debugging. Finally, we note that H.323 and SIP are improving themselves by learning from each other, and the differences between them are diminishing with each new version.

'SIP', as a tool of 'Ukrytie' shelter transformation into an ecologically safe system

International Nuclear Information System (INIS)

Dzhadd, K.; Shmidt, D.

1999-01-01

The Shelter implementation plan (SIP) was used for realisation of 'Ukrytie' stabilization and for its transformation into an ecologically safe system SIP includes logic of needed actions and process of solution adaption during 'Ukrytie' transformation

Estudio de planta piloto para peletización de residuos madereros y su utilización como combustible en hornos ladrilleros

Directory of Open Access Journals (Sweden)

Andrés González Hassig

2014-04-01

Full Text Available La biomasa es uno de los materiales más adecuados como combustible alternativo, pero por sus características de humedad, exceso de contenido de oxígeno y bajo poder calorífico, requiere ser sometida a procesos de pretratamiento. La peletización permite acondicionar la biomasa para su utilización directamente en procesos térmicos. El sector ladrillero tiene una gran demanda energética para sus procesos de secado y cocción y el uso de combustibles a partir de biomasa permite obtener reducciones importantes en emisiones atmosféricas. El estudio piloto comparó el desempeño energético y ambiental del uso de combustibles a partir de dos tipos de biomasas peletizadas —residuos de podas de césped, arbustos y árboles de la ciudad y residuos de producción de muebles y aglomerados, aserrín—. La biomasa con mejor desempeño fue el aserrín, debido a su menor consumo energético en el proceso de pretratamiento, aspecto que arroja una mayor productividad en su uso. Adicionalmente, se observó una reducción en los costos de suministro de combustible entre un 7 % y 10 %, sustituyendo un 20 % del carbón utilizado en el proceso.

An IMS testbed for SIP applications

DEFF Research Database (Denmark)

Caba, Cosmin Marius; Soler, José

2013-01-01

The paper presents the design and implementation of an emulation platform for the IP Multimedia Subsystem. The SIP Servlet API v1.1 has been used to implement the final system. The purpose of the emulation is to offer to IMS service developers an environment where they can integrate development...

DoS attacks targeting SIP server and improvements of robustness

OpenAIRE

Vozňák, Miroslav; Šafařík, Jakub

2012-01-01

The paper describes the vulnerability of SIP servers to DoS attacks and methods for server protection. For each attack, this paper describes their impact on a SIP server, evaluation of the threat and the way in which they are executed. Attacks are described in detail, and a security precaution is made to prevent each of them. The proposed solution of the protection is based on a specific topology of an intrusion protection systems components consisting of a combination of...

Pumping characteristics of sputter ion pump (SIP) and titanium sublimation pump (TSP) combination

International Nuclear Information System (INIS)

Ratnakala, K.C.; Patel, R.J.; Bhavsar, S.T.; Pandiyar, M.L.; Ramamurthi, S.S.

1995-01-01

For achieving hydrocarbon free, clean ultra high vacuum, SIP-TSP combination is one of the ideal choice for pumping. For the SRS facility in Centre for Advanced Technology (CAT), we are utilising this combination, enmass. For this purpose, two modules of these combination set-ups are assembled, one with the TSP as an integral part of SIP and the other, with TSP as a separate pump mounted on the top of SIP. The pump bodies were vacuum degassed at 700 degC at 10 -5 mbar for 3 hrs. An ultimate vacuum of 3 x 10 -11 mbar was achieved, after a bake-out at 250 degC for 4 hrs, followed by continuous SIP pumping for 48 hrs, with two TSP flashing at approximately 10 hrs interval. The pump-down patterns as well as the pressure-rise patterns are studied. (author). 2 refs., 5 figs

SMR-Based Adaptive Mobility Management Scheme in Hierarchical SIP Networks

Directory of Open Access Journals (Sweden)

KwangHee Choi

2014-10-01

Full Text Available In hierarchical SIP networks, paging is performed to reduce location update signaling cost for mobility management. However, the cost efficiency largely depends on each mobile node’s session-to-mobility-ratio (SMR, which is defined as a ratio of the session arrival rate to the movement rate. In this paper, we propose the adaptive mobility management scheme that can determine the policy regarding to each mobile node’s SMR. Each mobile node determines whether the paging is applied or not after comparing its SMR with the threshold. In other words, the paging is applied to a mobile node when a mobile node’s SMR is less than the threshold. Therefore, the proposed scheme provides a way to minimize signaling costs according to each mobile node’s SMR. We find out the optimal threshold through performance analysis, and show that the proposed scheme can reduce signaling cost than the existing SIP and paging schemes in hierarchical SIP networks.

Influencia del porcentaje de mezcla del aceite de higuerilla en la obtención de combustible alternativo para motores diesel

Directory of Open Access Journals (Sweden)

Arnoldo Emilio Delgado

2011-01-01

Full Text Available En el presente artículo se describe el uso del aceite de higuerilla como combustible alternativo en motores diesel. Para este fi n, se obtiene biodiesel a partir de aceite de higuerilla mediante el proceso de transesterifi cación. Se prueban tres mezclas de biodiesel (B5%, B10% y B20% en un motor diesel, para el cual se midieron los siguientes parámetros: la potencia, el consumo de combustible, la temperatura del motor, y los gases de combustión;las mezclas fueron caracterizadas mediante la densidad, viscosidad, índice de refracción y calor de combustión. Se determinó que el uso del aceite de higuerilla en la mezcla genera un aumento en la viscosidad y el consumo de combustible, además también infl uye en la reducción del poder calorífico, potencia del motor, los gases de combustión como el CO y CO2, los óxidos de azufre, los hidrocarburos, la opacidad en los humos del escape del motor y ocasiona un equilibrio en el rendimiento observado en el motor diesel, manifi esto en las temperaturas del motor.

SIP-FS: a novel feature selection for data representation

Directory of Open Access Journals (Sweden)

Yiyou Guo

2018-02-01

Full Text Available Abstract Multiple features are widely used to characterize real-world datasets. It is desirable to select leading features with stability and interpretability from a set of distinct features for a comprehensive data description. However, most of existing feature selection methods focus on the predictability (e.g., prediction accuracy of selected results yet neglect stability. To obtain compact data representation, a novel feature selection method is proposed to improve stability, and interpretability without sacrificing predictability (SIP-FS. Instead of mutual information, generalized correlation is adopted in minimal redundancy maximal relevance to measure the relation between different feature types. Several feature types (each contains a certain number of features can then be selected and evaluated quantitatively to determine what types contribute to a specific class, thereby enhancing the so-called interpretability of features. Moreover, stability is introduced in the criterion of SIP-FS to obtain consistent results of ranking. We conduct experiments on three publicly available datasets using one-versus-all strategy to select class-specific features. The experiments illustrate that SIP-FS achieves significant performance improvements in terms of stability and interpretability with desirable prediction accuracy and indicates advantages over several state-of-the-art approaches.

Technologies for the treatment of the sulfur dioxide and nitrogen oxides generated by the combustion in open chamber; Tecnologias para el tratamiento de dioxido de azufre y oxidos de nitrogeno generados por la combustion en camara abierta

Energy Technology Data Exchange (ETDEWEB)

Salazar Villalpando, Maria Dolores [Instituto Mexicano del Petroleo, Mexico, D. F. (Mexico)

1993-12-31

In general terms, there are only three ways of avoiding the sulfur dioxide and the nitrogen oxides, generated by the combustion in open chamber, from contaminating the air; the first one is utilizing low sulfur and nitrogen content fuels, the second one is by controlling the parameters that affect the combustion and the third one to treat and/or clean the gases before exhausting them to the air. In this document, some of the treatments for diminishing the pollutant emissions generated by the combustion in open chamber, are presented. [Espanol] En terminos generales, solo existen 3 maneras de evitar que el dioxido de azufre y oxidos de nitrogeno generados por la combustion en camara abierta sigan contaminando el aire, la primera es utilizar un combustible de bajo contenido de azufre y nitrogeno, la segunda es controlar los parametros que afectan la combustion, y la tercera es tratar y/o limpiar los gases antes de emitirlos a la atmosfera. En este documento se presentan algunos tratamientos para disminuir las emisiones de contaminantes generados por la combustion en camara abierta.

Technologies for the treatment of the sulfur dioxide and nitrogen oxides generated by the combustion in open chamber; Tecnologias para el tratamiento de dioxido de azufre y oxidos de nitrogeno generados por la combustion en camara abierta

Energy Technology Data Exchange (ETDEWEB)

Salazar Villalpando, Maria Dolores [Instituto Mexicano del Petroleo, Mexico, D. F. (Mexico)

1992-12-31

In general terms, there are only three ways of avoiding the sulfur dioxide and the nitrogen oxides, generated by the combustion in open chamber, from contaminating the air; the first one is utilizing low sulfur and nitrogen content fuels, the second one is by controlling the parameters that affect the combustion and the third one to treat and/or clean the gases before exhausting them to the air. In this document, some of the treatments for diminishing the pollutant emissions generated by the combustion in open chamber, are presented. [Espanol] En terminos generales, solo existen 3 maneras de evitar que el dioxido de azufre y oxidos de nitrogeno generados por la combustion en camara abierta sigan contaminando el aire, la primera es utilizar un combustible de bajo contenido de azufre y nitrogeno, la segunda es controlar los parametros que afectan la combustion, y la tercera es tratar y/o limpiar los gases antes de emitirlos a la atmosfera. En este documento se presentan algunos tratamientos para disminuir las emisiones de contaminantes generados por la combustion en camara abierta.

Análise do EIA/RIMA do Terminal de Combustíveis da Paraíba (TECOP para fins de licenciamento ambiental

Directory of Open Access Journals (Sweden)

Valdeniza Delmondes Pereira

2016-09-01

Full Text Available O estudo de impacto ambiental precede ao licenciamento ambiental, sendo obrigatório para atividades efetiva ou potencialmente poluidoras ou capazes de degradar o meio ambiente. Este trabalho teve como objetivo fazer a análise do EIA/RIMA do Terminal de Combustíveis da Paraíba Ltda-TECOP, observando se foram cumpridas as exigências legais para a caracterização dos impactos ambientais, e verificando também a existência de medidas mitigadoras para os impactos adversos e indicação de monitoramento para os referidos impactos identificados. Trata-se de uma pesquisa descritiva e documental, que teve como objetos de estudo, o EIA/RIMA e o Processo de Licenciamento Ambiental do TECOP, cujos dados foram coletados junto ao Setor de Documentação da SUDEMA. O EIA/RIMA se mostrou extremamente superficial no que diz respeito à caracterização dos impactos ambientais, estes não sendo devidamente caracterizados conforme determina a Resolução Conama 01/86, artigo 6, inciso II. Os atributos para a correta caracterização dos impactos não foram levados em consideração sequer para os principais impactos adversos passíveis de ocorrerem na fase de operação do empreendimento. O estudo também não mostrou clareza quanto à proposição das medidas mitigadoras e monitoramento para os impactos identificados, pois nem todos os impactos adversos continham a indicação de mitigação e como seriam monitorados.

HTSSIP: An R package for analysis of high throughput sequencing data from nucleic acid stable isotope probing (SIP experiments.

Directory of Open Access Journals (Sweden)

Nicholas D Youngblut

Full Text Available Combining high throughput sequencing with stable isotope probing (HTS-SIP is a powerful method for mapping in situ metabolic processes to thousands of microbial taxa. However, accurately mapping metabolic processes to taxa is complex and challenging. Multiple HTS-SIP data analysis methods have been developed, including high-resolution stable isotope probing (HR-SIP, multi-window high-resolution stable isotope probing (MW-HR-SIP, quantitative stable isotope probing (qSIP, and ΔBD. Currently, there is no publicly available software designed specifically for analyzing HTS-SIP data. To address this shortfall, we have developed the HTSSIP R package, an open-source, cross-platform toolset for conducting HTS-SIP analyses in a straightforward and easily reproducible manner. The HTSSIP package, along with full documentation and examples, is available from CRAN at https://cran.r-project.org/web/packages/HTSSIP/index.html and Github at https://github.com/buckleylab/HTSSIP.

Gasification of heavy fuels to produce electrical energy and hydrogen; Gasificacion de combustibles pesados para producir energia electrica e hidrogeno

Energy Technology Data Exchange (ETDEWEB)

Vera Garcia, Oscar Alberto [Universidad Nacional Autonoma de Mexico(UNAM), Mexico, D.F. (Mexico)

2006-11-15

A description is presented of the different types of integrated gasifiers that at the moment are used in the synthesis gas production to be used, with different fuels in the generation of electricity in Combined Cycle. Three cases of application of integrated gasifiers are analyzed. The first it is the engine power upgrade of a Combined Cycle power plant to natural gas to burn fuel of bad quality in an integrated gasifier (CCGI). The second one examines the incorporation of a shift reactor in which the synthesis gas is transformed into CO{sub 2} and H{sub 2} which are used to move the turbine to gas, adapted for pure hydrogen. Finally is studied the amount of other by-products that can be obtained from these co-generation cycles such as CO{sub 2} to be used in secondary recovery of oil wells, N{sub 2} to be used in the fertilizer industry or in the proper oil production and H{sub 2} to be used in the oil industry or the generation with fuel cells. All the cases are studied in quantitative form, making the balance of mass and energy of each one of them. In order to give more practical sense to the calculations, the engineering data of the Valladolid Power station of Comision Federal de Electricidad (CFE) have been taken as base. This article provides a basic idea, but very practical, to estimate the fuel consumption of the different modes of arrangement of a CCGI power station, as well as the volumes of the different gases that can be produced and the modifications to the size of the equipment that is required. [Spanish] Se presenta una descripcion de los diferentes tipos de gasificadores integrados que actualmente se utilizan en la produccion de gas de sintesis para ser utilizados, con diferentes combustibles, en la generacion de electricidad con Ciclo Combinado. Se analizan tres casos de aplicacion de gasificadores integrados. El primero es la repotenciacion de una planta de Ciclo Combinado a gas natural para quemar combustible de mala calidad en un gasificador

Materiais cerâmicos para células a combustível Ceramic materials for fuel cells

Directory of Open Access Journals (Sweden)

D. Z. de Florio

2004-12-01

Full Text Available A partir da definição de células a combustível, é feita uma introdução sucinta dos tipos de células e dos materiais cerâmicos que são empregados em projeto e fabricação destes dispositivos geradores de energia elétrica. Tomando por base a ampla literatura científica disponível em publicações periódicas internacionais indexadas e arbitradas, bem como patentes, são relatados com detalhes os materiais cerâmicos com comportamento elétrico adequado para uso como eletrólitos, anodos, catodos, interconectores e selantes, que são os componentes básicos de células a combustível de óxidos sólidos. Por fim, é feita uma avaliação do estado da arte na pesquisa e desenvolvimento de materiais cerâmicos para uso em células a combustível de óxidos sólidos.Basic definitions of fuel cells and a brief introduction of different types of fuel cells are given. A review of the most important ceramic materials being considered for the design and fabrication of devices for producing electrical energy is presented. Ceramic materials with suitable electrical behavior to be used as electrolytes, anodes, cathodes, interconnectors, and sealants of solid oxide fuel cells are reported with details, taking into account the large number of available indexed and refereed scientific publications and patents. Finally, an evaluation of the state of the art of the research and development of ceramic materials for solid oxide fuel cells is presented.

SIP-ing the elixir of youth.

Science.gov (United States)

Mair, William; Steffen, Kristan K; Dillin, Andrew

2011-09-16

AMP-activated protein kinase (AMPK) is a conserved cellular fuel gauge previously implicated in aging. In this issue, Lu et al. (2011) describe how age-related deacetylation of Sip2, a subunit of the AMPK homolog in yeast, acts as a life span clock that can be wound backward or forward to modulate longevity. Copyright © 2011 Elsevier Inc. All rights reserved.

The Early Psychosis Screener (EPS): Quantitative validation against the SIPS using machine learning.

Science.gov (United States)

Brodey, B B; Girgis, R R; Favorov, O V; Addington, J; Perkins, D O; Bearden, C E; Woods, S W; Walker, E F; Cornblatt, B A; Brucato, G; Walsh, B; Elkin, K A; Brodey, I S

2018-01-18

Machine learning techniques were used to identify highly informative early psychosis self-report items and to validate an early psychosis screener (EPS) against the Structured Interview for Psychosis-risk Syndromes (SIPS). The Prodromal Questionnaire-Brief Version (PQ-B) and 148 additional items were administered to 229 individuals being screened with the SIPS at 7 North American Prodrome Longitudinal Study sites and at Columbia University. Fifty individuals were found to have SIPS scores of 0, 1, or 2, making them clinically low risk (CLR) controls; 144 were classified as clinically high risk (CHR) (SIPS 3-5) and 35 were found to have first episode psychosis (FEP) (SIPS 6). Spectral clustering analysis, performed on 124 of the items, yielded two cohesive item groups, the first mostly related to psychosis and mania, the second mostly related to depression, anxiety, and social and general work/school functioning. Items within each group were sorted according to their usefulness in distinguishing between CLR and CHR individuals using the Minimum Redundancy Maximum Relevance procedure. A receiver operating characteristic area under the curve (AUC) analysis indicated that maximal differentiation of CLR and CHR participants was achieved with a 26-item solution (AUC=0.899±0.001). The EPS-26 outperformed the PQ-B (AUC=0.834±0.001). For screening purposes, the self-report EPS-26 appeared to differentiate individuals who are either CLR or CHR approximately as well as the clinician-administered SIPS. The EPS-26 may prove useful as a self-report screener and may lead to a decrease in the duration of untreated psychosis. A validation of the EPS-26 against actual conversion is underway. Copyright © 2017 Elsevier B.V. All rights reserved.

Approach to stress tests in SIP environment based on marginal analysis

OpenAIRE

Voznak, Miroslav; Rozhon, Jan

2013-01-01

In the field of performance metrics and measurements of SIP (Session Initiation Protocol) Proxy and B2BUA (Back-to-Back User Agent) no standardized methodology has been presented yet. This gap results in a problematic determination of a hardware, the performance of which would be cost-effective and sufficient for the running the SIP Server in a given environment. Today practice relies on the administrator’s skills and experience with the needs of the telephony infrastructure. From this and th...

A Secured Load Mitigation and Distribution Scheme for Securing SIP Server

Directory of Open Access Journals (Sweden)

Vennila Ganesan

2017-01-01

Full Text Available Managing the performance of the Session Initiation Protocol (SIP server under heavy load conditions is a critical task in a Voice over Internet Protocol (VoIP network. In this paper, a two-tier model is proposed for the security, load mitigation, and distribution issues of the SIP server. In the first tier, the proposed handler segregates and drops the malicious traffic. The second tier provides a uniform load of distribution, using the least session termination time (LSTT algorithm. Besides, the mean session termination time is minimized by reducing the waiting time of the SIP messages. Efficiency of the LSTT algorithm is evaluated through the experimental test bed by considering with and without a handler. The experimental results establish that the proposed two-tier model improves the throughput and the CPU utilization. It also reduces the response time and error rate while preserving the quality of multimedia session delivery. This two-tier model provides robust security, dynamic load distribution, appropriate server selection, and session synchronization.

SIP Shear Walls: Cyclic Performance of High-Aspect-Ratio Segments and Perforated Walls

Science.gov (United States)

Vladimir Kochkin; Douglas R. Rammer; Kevin Kauffman; Thomas Wiliamson; Robert J. Ross

2015-01-01

Increasing stringency of energy codes and the growing market demand for more energy efficient buildings gives structural insulated panel (SIP) construction an opportunity to increase its use in commercial and residential buildings. However, shear wall aspect ratio limitations and lack of knowledge on how to design SIPs with window and door openings are barriers to the...

Sipping machine control system new design to perform integrity of nuclear fuel test in Cofrentes power plant

Energy Technology Data Exchange (ETDEWEB)

Palomo, M., E-mail: mpalomo@iqn.upv.es [Departamento de Ingenieria Quimica y Nuclear. Universidad Politecnica de Valencia (Spain); Urrea, M., E-mail: Matias.urrea@iberdrola.es [C.N.Cofrentes - Iberdrola Generacion S.A., Cofrentes, Valencia (Spain); Curiel, M., E-mail: m.curiel@lainsa.com [LAINSA Grupo Dominguis, Valencia (Spain); Arnaldos, A., E-mail: a.arnaldos@titaniast.com [TITANIA Servicios Tecnologicos SL, Grupo Dominguis, Valencia (Spain)

2011-07-01

This paper we present is related to SIPPING machine control system new design to perform integrity of nuclear fuel test. This test is a non destructive technique used for evaluating the radiated nuclear fuel coating structural integrity. It is based on the radioactive emission detection of fission elements in the reactor cooling system, using the fuel inspection equipment (SIPPING). SIPPING equipment consists of one simultaneous test bell-shaped vessel of eight fuel elements, and another one for individual element test, a control workstation and some accessories (cables, thermocouples, hoses). SIPPING inspection is carried out by means of fuel element vessel. Through air injection, water flows around the element and heat evacuation is reduced, so fuel elements temperature increases. Those elements with faults shall expelled fission components dissolved in water and/or as a gas component. The project aim is the SIPPING system control design and software based on LabVIEW, for control, monitoring and documentation of the SIPPING Test. This project shall give a major functionality to the system and, at the same time, shall facilitate the user a friendlier and interactive environment allowing: to substitute the present work platform with a real-time electronic system based on cRIO and a control software ad-hoc designed for SIPPING system; to equip new system of a major redundancy for data storage, minimising loss probability of the same. (author)

Analysis regarding steam generator furnace's incident heat, temperature and composition of combustion gases; Analisis de calor incidente, temperatura y composicion de gases de combustion en hornos de generadores de vapor

Energy Technology Data Exchange (ETDEWEB)

Diego Marin, Antonio [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

2006-07-01

In order to obtain more precise evaluations of the combustion process in the furnace of a steam generator a suction pyrometer has been integrated to measure the temperature of the combustion gases; an ellipsoidal radiometer to measure the incident heat by thermal radiation in the water walls; a water cooled probe to determine the particle concentration, as well as a water cooled probe to determine the composition of the combustion gases present. This document clarifies the form of use of these instruments and their engineering specifications, simultaneously presenting an analysis that considers, unlike others, the internal conditions of the furnace to obtain a more precise evaluation of the efficiency that the combustion process presents and bases for the taking of preventive actions in specific zones of the furnace. Thus, the present work exhibits instruments and techniques of analysis to study the phenomena occurring within a steam generator. [Spanish] Con el fin de obtener evaluaciones mas precisas del proceso de combustion en el horno de un generador de vapor, se ha integrado un pirometro de succion para medir la temperatura de los gases de combustion; un radiometro elipsoidal para medir el calor incidente por radiacion termica en las paredes del agua; una sonda enfriada con agua para determinar la concentracion de particulas, asi como una sonda refrigerada con agua para determinar la composicion de los gases de combustion presentes. Este documento aclara la forma de uso de estos instrumentos y sus especificaciones tecnicas, a la vez que presenta un analisis que considera, a diferencia de otros, las condiciones internas del horno para obtener una evaluacion mas precisa sobre la eficiencia del proceso de combustion y bases para la toma de acciones preventivas en zonas especificas del horno. Asi, el presente trabajo exhibe instrumentos y tecnicas de analisis para estudiar los fenomenos que ocurren dentro de un generador de vapor.

Calculation of fuel element temperature TRIGA 2000 reactor in sipping test tubes using CFD

International Nuclear Information System (INIS)

Sudjatmi KA

2013-01-01

It has been calculated the fuel element temperature in the sipping test of Bandung TRIGA 2000 reactor. The calculation needs to be done to ascertain that the fuel element temperatures are below or at the limit of the allowable temperature fuel elements during reactor operation. ensuring that the implementation of the test by using this device, the temperature is still within safety limits. The calculation is done by making a model sipping test tubes containing a fuel element surrounded by 9 fuel elements. according to the position sipping test tubes in the reactor core. by using Gambit. Dimensional model adapted to the dimensions of the tube and the fuel element in the reactor core of Bandung TRIGA 2000 reactor. Sipping test Operation for each fuel element performed for 30 minutes at 300 kW power. Calculations were performed using CFD software and as input adjusted parameters of TRIGA 2000 reactor. Simulations carried out on the operation of the 30, 60, 90, 120, 150, 180 and 210 minutes. The calculation result shows that the temperature of the fuel in tubes sipping test of 236.06 °C, while the temperature of the wall is 87.58 °C. The maximum temperature in the fuel center of TRIGA 2000 reactor in normal operation is 650 °C. and the boiling is not allowed in the reactor. So it can be concluded that the operation of the sipping test device are is very safe because the fuel center temperature is below the temperature limits the allowable fuel under normal operating conditions as well as the fuel element wall temperature is below the boiling temperature of water. (author)

Desenvolvimento de eletrodos de pasta de carbono modificada com 2-aminotiazol sílica gel para a determinação de metais em etanol combustível

OpenAIRE

Takeuchi, Regina Massako [UNESP

2007-01-01

Neste trabalho foram desenvolvidos métodos eletroanalíticos para a determinação de íons metálicos em etanol combustível, empregando-se eletrodos de pasta de carbono modificada com uma sílica organofuncionalizada com grupos 2-aminotiazol (CPE-SiAt). Foi realizado um estudo comparativo entre dois aglutinantes: Nujol® e parafina; sendo observado que este último foi mais apropriado para aplicações em amostras comerciais de etanol combustível. Além da utilização dos CPE-SiAt, empregou-se também um...

The Social Interaction Phobia Scale: Continued support for the psychometric validity of the SIPS using clinical and non-clinical samples.

Science.gov (United States)

Menatti, Alison R; Weeks, Justin W; Carleton, R Nicholas; Morrison, Amanda S; Heimberg, Richard G; Hope, Debra A; Blanco, Carlos; Schneier, Franklin R; Liebowitz, Michael R

2015-05-01

The present study sought to extend findings supporting the psychometric validity of a promising measure of social anxiety (SA) symptoms, the Social Interaction Phobia Scale (SIPS; Carleton et al., 2009). Analyses were conducted using three samples: social anxiety disorder (SAD) patients, generalized anxiety disorder (GAD) patients, and healthy controls. SIPS scores of SAD patients demonstrated internal consistency and construct validity, and the previously demonstrated three-factor structure of the SIPS was replicated. Further, the SIPS total score uniquely predicted SA symptoms, and SIPS scores were significantly higher for SAD patients than GAD patients or controls. Two cut-off scores that discriminated SAD patients from GAD patients and from healthy controls were identified. The current study is the first to replicate the SIPS three-factor model in a large, treatment-seeking sample of SAD patients and establish a cut-off score discriminating SAD from GAD patients. Findings support the SIPS as a valid, SAD-specific assessment instrument. Copyright © 2015 Elsevier Ltd. All rights reserved.

Combustion of drops of Mexican fuel oils with high asphaltenes content; Combustion de gotas de combustoleos mexicanos con alto contenido de asfaltenos

Energy Technology Data Exchange (ETDEWEB)

Garcia Rodriguez, Jose Francisco [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

1998-09-01

In this work the combustion of fuel drops with a content of 18% of asphaltenes has been studied . The results obtained for this fuel were compared with the ones obtained for another with a content of 12% asphaltenes. The drops were suspended in a platinum filament and burned in an spherical radiant furnace. The drop size varied between 600 and 800 microns. The fuel drops with 12% asphaltenes showed shorter combustion times, a smaller diameter increment of the smaller diameter during the combustion stages and also a shorter burning time of the carbonaceous residue than the fuel drops with a content of 18% asphaltenes. [Espanol] En el presente trabajo se ha estudiado la combustion de gotas de combustible con 18% de contenido de asfaltenos. Los resultados obtenidos para este combustible se compararon con los obtenidos para otro con 12% de contenido de asfaltenos. Las gotas fueron suspendidas en un filamento de platino y quemadas en un horno radiante esferico. El tamano de las gotas vario entre 600 y 800 micras. Las gotas de combustible con 12% de asfaltenos mostraron tiempos de combustion mas cortos, un incremento del diametro menor durante las etapas de combustion y un tiempo de quemado del residuo carbonoso tambien mas corto que las gotas del combustible con 18% de contenido de asfaltenos.

Energy Efficiency and Renewable Energy in SIPs and TIPs

Science.gov (United States)

Tools and guides to encourage state, tribal and local agencies to consider incorporating Energy Efficiency (EE) and Renewable Energy (RE) policies and programs in their State and Tribal Implementation Plans (SIPs/TIPs).

76 FR 28437 - Disease, Disability, and Injury Prevention and Control Special Interest Project (SIP): Initial...

Science.gov (United States)

2011-05-17

... DEPARTMENT OF HEALTH AND HUMAN SERVICES Centers for Disease Control and Prevention Disease, Disability, and Injury Prevention and Control Special Interest Project (SIP): Initial Review The meeting... Disease or Treated by Assisted Reproductive Technology, SIP11-048, Panel F,'' initial review In accordance...

JACoW SIP4C/C++ at CERN - Status and lessons learned

CERN Document Server

Jensen, Steen; Dworak, Andrzej; Gourber-Pace, Marine; Hoguin, Frederic; Lauener, Joel; Locci, Frank; Sigerud, Katarina; Sliwinski, Wojciech

2018-01-01

After 4 years of promoting the Software Improvement Process for C/C++ (SIP4C/C++) initiative at CERN, we describe the current status for tools and procedures along with how they have been integrated into our environment. Based on feedback from four project teams, we present reasons for and against their adoption. Finally, we show how SIP4C/C++ has improved development and delivery processes as well as the first-line support of delivered products.

Determinantes en la elección del tipo de combustible para cocción de alimentos en asentamientos humanos

Directory of Open Access Journals (Sweden)

Carlos Meza

2010-04-01

Full Text Available EL ARTÍCULO PRESENTA LOS DETERMINANTES EN LA ELECCIÓN DEL TIPO DE combustible primario para cocción de alimentos en cuatro asentamientos humanos urbanos localizados en los departamentos de Managua y León. Se eligió un modelo logístico binario (Logit que permitió concluir que los factores que inciden en la elecciónson: el ingreso, los niveles de educación, el departamento al que pertenecen los barrios, número de miembros del hogar y la edad del cabeza de familia. Este estudio ofrece un punto de inicio en la discusión de los aspectos de relevancia en la demanda de combustibles a nivel urbano en Managua y León.

Design of SIP transformation server for efficient media negotiation

Science.gov (United States)

Pack, Sangheon; Paik, Eun Kyoung; Choi, Yanghee

2001-07-01

Voice over IP (VoIP) is one of the advanced services supported by the next generation mobile communication. VoIP should support various media formats and terminals existing together. This heterogeneous environment may prevent diverse users from establishing VoIP sessions among them. To solve the problem an efficient media negotiation mechanism is required. In this paper, we propose the efficient media negotiation architecture using the transformation server and the Intelligent Location Server (ILS). The transformation server is an extended Session Initiation Protocol (SIP) proxy server. It can modify an unacceptable session INVITE message into an acceptable one using the ILS. The ILS is a directory server based on the Lightweight Directory Access Protocol (LDAP) that keeps userí*s location information and available media information. The proposed architecture can eliminate an unnecessary response and re-INVITE messages of the standard SIP architecture. It takes only 1.5 round trip times to negotiate two different media types while the standard media negotiation mechanism takes 2.5 round trip times. The extra processing time in message handling is negligible in comparison to the reduced round trip time. The experimental results show that the session setup time in the proposed architecture is less than the setup time in the standard SIP. These results verify that the proposed media negotiation mechanism is more efficient in solving diversity problems.

Diagnóstico técnico de carbones térmicos para la obtención del combustible ccta en boyacá

OpenAIRE

TRIVIÑO RESTREPO, MARÍA DEL PILAR; MOLINA GALLEGO, CLAUDIA PATRICIA

2009-01-01

Este estudio evalúa los potenciales carbones térmicos de Boyacá, Colombia, para ser utilizados en la obtención del combustible CCTA (mezcla densa de carbón pulverizado disperso en emulsiones de combustóleo o fuel oil y agua), el cual puede sustituir el carbón en la producción de materiales cerámicos. Este sector productivo a nivel regional presenta un desarrollo insipiente, debido a que se utilizan principalmente hornos comunes o locos a carbón, sin obtener variación, ni aumento en la producc...

Scilab and SIP for Image Processing

OpenAIRE

Fabbri, Ricardo; Bruno, Odemir Martinez; Costa, Luciano da Fontoura

2012-01-01

This paper is an overview of Image Processing and Analysis using Scilab, a free prototyping environment for numerical calculations similar to Matlab. We demonstrate the capabilities of SIP -- the Scilab Image Processing Toolbox -- which extends Scilab with many functions to read and write images in over 100 major file formats, including PNG, JPEG, BMP, and TIFF. It also provides routines for image filtering, edge detection, blurring, segmentation, shape analysis, and image recognition. Basic ...

A new technique to modify hypereutectic Al-24%Si alloys by a Si-P master alloy

Energy Technology Data Exchange (ETDEWEB)

Wu Yaping; Wang Shujun; Li Hui [Key Laboratory of Liquid Structure and Heredity of Materials, Ministry of Education, Shandong University, 73 Jingshi Road, Jinan 250061 (China); Liu Xiangfa [Key Laboratory of Liquid Structure and Heredity of Materials, Ministry of Education, Shandong University, 73 Jingshi Road, Jinan 250061 (China)], E-mail: xfliu@sdu.edu.cn

2009-05-27

The modification effect of a Si-P master alloy on Al-24%Si alloy was investigated by using electron probe micro-analyzer (EPMA) and optical microscopy (OM). The dissolution problem of the Si-P master alloys was solved by changing the sequence of addition. When the Si-P master alloy was added into Al melt before the addition of silicon, the best modification effect could be achieved. The modification parameters of the master alloy on Al-24%Si alloy were optimized through designing and analyzing the orthogonal experiment, and their influences on the modification effect were discussed. The results show that the influence of temperature on the modification effect is the greatest, followed by the addition level, and the holding time is the least. The optimized modification parameters are the modification temperature of 810 deg. C, the addition level of 0.35 wt.%, the holding time of 30 min + 50 min whose meaning is that the Si-P master alloy is added firstly to the molten Al, and silicon is added 30 min later, then holding another 50 min. In addition, the modification mechanism of the Si-P master alloy on Al-24%Si alloy was also discussed.

Louisiana SIP: LAC 33:III Ch 2147. Limiting Volatile Organic Compound (VOC) Emissions from Reactor Processes and Distillation Operations in Synthetic Organic Chemical manufacturing Industry (SOCMI); SIP effective 2011-08-04 (LAd34) to 2017-09-27

Science.gov (United States)

Louisiana SIP: LAC 33:III Ch 2147. Limiting Volatile Organic Compound (VOC) Emissions from Reactor Processes and Distillation Operations in Synthetic Organic Chemical manufacturing Industry (SOCMI); SIP effective 2011-08-04 (LAd34) to 2017-09-27

77 FR 31358 - Disease, Disability, and Injury Prevention and Control Special Interest Projects (SIPs): Initial...

Science.gov (United States)

2012-05-25

... announced below concerns Research to Enhance Community- Based Fall Prevention among Older Adults, SIP12-058, and Developing a Compendium of Measures and Questions to Assess Mobility: A Focus on Older Adult... Older Adults, SIP12-058, and Developing a Compendium of Measures and Questions to Assess Mobility: A...

Study on the essential variables for pipe outer surface irradiated laser stress improvement process (L-SIP). Development of pipe outer surface irradiated laser stress improvement process (L-SIP)

International Nuclear Information System (INIS)

Ohta, Takahiro; Kamo, Kazuhiko; Muroya, Itaru; Asada, Seiji; Nakamura, Yasuo

2009-01-01

The new process called L-SIP (outer surface irradiated Laser Stress Improvement Process) is developed to improve the tensile residual stress of the inner surface near the butt welded joints of pipes in the compression stress. The temperature gradient occurs in the thickness of pipes in heating the outer surface rapidly by laser beam. By the thermal expansion difference between the inner surface and the outer surface, the compression stress occurs near the inner surface of pipes. In this paper, the essential variables for L-SIP is studied by experimental and FEM analysis. The range of the essential variables for L-SIP, which are defined by thermo-elastic FEM analysis, are Tmax=550 - 650degC, L Q /√rh ≥ 3, W Q /√rh ≥ 1.7, and, 0.04 ≤ F 0 ≤ 0.10 where Tmax is maximum temperature on the monitor point of the outer surface, F 0 is k x τ 0 /h 2 , k is thermal diffusivity coefficient, τ 0 is the temperature rise time from 100degC to maximum temperature on the monitor point of the outer surface, W Q is τ 0 x v, υ is moving velocity, L Q is the uniform temperature length in the axial direction, h is thickness of the pipe, and r is average radius of the pipe. It is showed by thermo-elastic-plastic FEM analysis that the residual stresses near the inner surface of pipes are improved in 4 different size pipes under the same essential variables. L-SIP is actually applied to welding joints of 4B x Sch160 and 2B x Sch80 SUS304 type stainless steel pipes within the defined range of the essential variables. The measured welding residual stresses on the inner surface near the welding joints are tensile. The residual stresses on the inner surface change to compression in all joints by L-SIP. (author)

Pilas de combustible de Membrana polimérica

OpenAIRE

Asensio, Juan; Peña, Juan; Pérez-Coll, Domingo; Ruiz-Morales, Juan; Marrero -López, David; Núñez, Pedro; Ballesteros, Belèn; Canales-Vázquez, Jesús; Borrós, Salvador; Gómez-Romero, Pedro

2011-01-01

En este trabajo revisamos brevemente las pilas de combustible poliméricas (PEM) basadas en membranas de intercambio protónico y que constituyen la tecnología idónea de pilas de combustible de baja temperatura, y por tanto las más adecuadas para aplicación en transporte. Revisaremos los materiales que las componen pero tambíen los desarrollos necesarios para su implantación definitiva en un mercado inclemente con las tecnologías caras, por límpias que sean.

Generation of a gene cassette for genetically engineered Salmonella Enteritidis in the specific region of the sipC gene

Directory of Open Access Journals (Sweden)

M Ghasemi

2017-05-01

Full Text Available Introduction: Salmonellosis is an infection caused by eating contaminated food with Salmonella, and it can occur in humans and other animals. Salmonella has acquired the ability to create the infection due to the presence of several virulence genes. One of the virulence genes of salmonella is sipC gene that coding the SipC protein. The aim of this study was creating the gene cassette to genetically engineered Salmonella enteritidis in the specific region of the sipC gene. Methods: In this study, after DNA extraction from Salmonella, the upstream and downstream regions of the sipC gene was amplified based on PCR method. The PCR products were cloned with T/A cloning method and they were inserted into the pGEM vector. In order to generate the final gene cassette, each of the upstream and downstream regions of the sipC gene was subcloned into the pET32 vector, and cloning accuracy was assessed by PCR and enzyme digestion methods. Results: Amplification of the 320 bp upstream and 206 bp downstream of sipC gene was successful by PCR method. T/A cloning of these fragments were caused the formation of two pGEM-up and pGEM-down recombinant vectors. Results that were confirmed the sub-cloning accuracy indicate the formation of the final pET32-up-down gene cassette. Conclusion: The generated gene cassette in this study was considered as a multi-purpose cassette that is able to specific gene manipulation of Salmonella sipC gene by homologous recombination matched. This gene cassette has the necessary potential for sipC gene deletion or insertion of any useful gene instead of sipC gene.

Sipping machine control system new design to perform integrity of nuclear fuel test in Cofrentes power plant

Energy Technology Data Exchange (ETDEWEB)

Curiel, M. [Logistica y Acondicionamientos Industriales SAU, Sorolla Center, local 10, Av. de las Cortes Valencianas No. 58, 46015 Valencia (Spain); Palomo, M. J. [ISIRYM, Universidad Politecnica de Valencia, Camino de Vera s/n, Valencia (Spain); Urrea, M. [Iberdrola Generacion S. A., Central Nuclear Cofrentes, Carretera Almansa Requena s/n, 04662 Cofrentes, Valencia (Spain); Vaquer, J., E-mail: m.curiel@lainsa.co [TITANIA Servicios Tecnologicos SL, Sorolla Center, local 10, Av. de las Cortes Valencianas No. 58, 46015 Valencia (Spain)

2010-10-15

This paper related to Sipping machine control system new design to perform integrity of nuclear fuel test. This test is a non destructive technique used for evaluating the radiated nuclear fuel coating structural integrity. It is based on the radioactive emission detection of fission elements in the reactor cooling system, using the fuel inspection equipment Sipping. The equipment consists of one simultaneous test bell-shaped vessel of eight fuel elements, and another one for individual element test, a control workstation and some accessories (cables, thermocouples, hoses). Sipping inspection is carried out by means of fuel element vessel. Through air injection, water flows around the element and heat evacuation is reduced, so fuel elements temperature increases. Those elements with faults shall expelled fission components dissolved in water and/or as a gas component. The project aim is the Sipping system control design and software based on LabVIEWTM, for control, monitoring and documentation of the Sipping test. This project shall give a major functionality to the system and, at the same time, shall facilitate the user a friendlier and interactive environment allowing: 1) To substitute the present work platform with a real-time electronic system based on cRIO and a control software ad-hoc designed for Sipping system. 2) To equip new system of a major redundancy for data storage, minimising loss probability of the same. (Author)

Towards a Standard Psychometric Diagnostic Interview for Subjects at Ultra High Risk of Psychosis: CAARMS versus SIPS

Science.gov (United States)

Fusar-Poli, P.; Cappucciati, M.; Rutigliano, G.; Lee, T. Y.; Beverly, Q.; Bonoldi, I.; Lelli, J.; Kaar, S. J.; Gago, E.; Rocchetti, M.; Patel, R.; Bhavsar, V.; Tognin, S.; Badger, S.; Calem, M.; Lim, K.; Kwon, J. S.; Perez, J.; McGuire, P.

2016-01-01

Background. Several psychometric instruments are available for the diagnostic interview of subjects at ultra high risk (UHR) of psychosis. Their diagnostic comparability is unknown. Methods. All referrals to the OASIS (London) or CAMEO (Cambridgeshire) UHR services from May 13 to Dec 14 were interviewed for a UHR state using both the CAARMS 12/2006 and the SIPS 5.0. Percent overall agreement, kappa, the McNemar-Bowker χ 2 test, equipercentile methods, and residual analyses were used to investigate diagnostic outcomes and symptoms severity or frequency. A conversion algorithm (CONVERT) was validated in an independent UHR sample from the Seoul Youth Clinic (Seoul). Results. There was overall substantial CAARMS-versus-SIPS agreement in the identification of UHR subjects (n = 212, percent overall agreement = 86%; kappa = 0.781, 95% CI from 0.684 to 0.878; McNemar-Bowker test = 0.069), with the exception of the brief limited intermittent psychotic symptoms (BLIPS) subgroup. Equipercentile-linking table linked symptoms severity and frequency across the CAARMS and SIPS. The conversion algorithm was validated in 93 UHR subjects, showing excellent diagnostic accuracy (CAARMS to SIPS: ROC area 0.929; SIPS to CAARMS: ROC area 0.903). Conclusions. This study provides initial comparability data between CAARMS and SIPS and will inform ongoing multicentre studies and clinical guidelines for the UHR psychometric diagnostic interview. PMID:27314005

Towards a Standard Psychometric Diagnostic Interview for Subjects at Ultra High Risk of Psychosis: CAARMS versus SIPS

Directory of Open Access Journals (Sweden)

P. Fusar-Poli

2016-01-01

Full Text Available Background. Several psychometric instruments are available for the diagnostic interview of subjects at ultra high risk (UHR of psychosis. Their diagnostic comparability is unknown. Methods. All referrals to the OASIS (London or CAMEO (Cambridgeshire UHR services from May 13 to Dec 14 were interviewed for a UHR state using both the CAARMS 12/2006 and the SIPS 5.0. Percent overall agreement, kappa, the McNemar-Bowker χ2 test, equipercentile methods, and residual analyses were used to investigate diagnostic outcomes and symptoms severity or frequency. A conversion algorithm (CONVERT was validated in an independent UHR sample from the Seoul Youth Clinic (Seoul. Results. There was overall substantial CAARMS-versus-SIPS agreement in the identification of UHR subjects (n=212, percent overall agreement = 86%; kappa = 0.781, 95% CI from 0.684 to 0.878; McNemar-Bowker test = 0.069, with the exception of the brief limited intermittent psychotic symptoms (BLIPS subgroup. Equipercentile-linking table linked symptoms severity and frequency across the CAARMS and SIPS. The conversion algorithm was validated in 93 UHR subjects, showing excellent diagnostic accuracy (CAARMS to SIPS: ROC area 0.929; SIPS to CAARMS: ROC area 0.903. Conclusions. This study provides initial comparability data between CAARMS and SIPS and will inform ongoing multicentre studies and clinical guidelines for the UHR psychometric diagnostic interview.

Sipping machine control system new design to perform integrity of nuclear fuel test in Cofrentes power plant

International Nuclear Information System (INIS)

Curiel, M.; Palomo, M. J.; Urrea, M.; Vaquer, J.

2010-10-01

This paper related to Sipping machine control system new design to perform integrity of nuclear fuel test. This test is a non destructive technique used for evaluating the radiated nuclear fuel coating structural integrity. It is based on the radioactive emission detection of fission elements in the reactor cooling system, using the fuel inspection equipment Sipping. The equipment consists of one simultaneous test bell-shaped vessel of eight fuel elements, and another one for individual element test, a control workstation and some accessories (cables, thermocouples, hoses). Sipping inspection is carried out by means of fuel element vessel. Through air injection, water flows around the element and heat evacuation is reduced, so fuel elements temperature increases. Those elements with faults shall expelled fission components dissolved in water and/or as a gas component. The project aim is the Sipping system control design and software based on LabVIEWTM, for control, monitoring and documentation of the Sipping test. This project shall give a major functionality to the system and, at the same time, shall facilitate the user a friendlier and interactive environment allowing: 1) To substitute the present work platform with a real-time electronic system based on cRIO and a control software ad-hoc designed for Sipping system. 2) To equip new system of a major redundancy for data storage, minimising loss probability of the same. (Author)

40 CFR 51.125 - Emissions reporting requirements for SIP revisions relating to budgets for SO2 and NOX emissions.

Science.gov (United States)

2010-07-01

... SIP revisions relating to budgets for SO2 and NOX emissions. 51.125 Section 51.125 Protection of... SIP revisions relating to budgets for SO2 and NOX emissions. (a) For its transport SIP revision under § 51.123 and/or 51.124, each State must submit to EPA SO2 and/or NOX emissions data as described in...

Louisiana SIP: LAC 33:III Ch 21 Subchap J, 2147--Limiting Volatile Organic Compound (VOC) Emissions from Reactor Processes and Distillation Operations in Synthetic Organic Chemical manufacturing Industry (SOCMI); SIP effective 1998-02-02 (LAc74) to more..

Science.gov (United States)

Louisiana SIP: LAC 33:III Ch 21 Subchap J, 2147--Limiting Volatile Organic Compound (VOC) Emissions from Reactor Processes and Distillation Operations in Synthetic Organic Chemical manufacturing Industry (SOCMI); SIP effective 1998-02-02 (LAc74) more...

Desenvolvimento de membranas compósitas à base de nanocelulose para pilhas de combustível

OpenAIRE

Martins, Ana Patrícia Carvalho

2016-01-01

A presente dissertação tem como objetivo o desenvolvimento de membranas polieletrólitas baseadas em celulose bacteriana (CB) para aplicação em pilhas de combustível de condução protónica, que se espera ser uma solução ambientalmente sustentável. A CB é um material celulósico, com uma estrutura nanofibrilar tridimensional, biossintetizada por algumas estirpes de bactérias não patogénicas como é o caso da Gluconacetobacter sacchari. Devido a algumas das suas propriedades, nomeadamente a sua ele...

Construction of an electrolytic photocell fuel cell system used to energize a cellular telephone; Construccion de un sistema fotocelda-electrolizador-celda de combustible, utilizado para energizar un telefono celular

Energy Technology Data Exchange (ETDEWEB)

Fuentes Quezada, Eduardo; Rodriguez-Castellanos, A.; Solorza Feria, O. [CINVESTAV-IPN, Mexico, D.F. (Mexico)]. E-mail: edfq_1986@hotmail.com

2009-09-15

An increase in the worldwide population (roughly 6.3 billion people) has brought about a considerable increase in the demand for energy in order to meet national energy and development needs. Oil and carbon are currently the fuels that are most widely used to generate energy. Nevertheless, their extraction and transport, in addition to their combustion, produce residual pollutants, such as carbon bioxide which is released into the atmosphere and contributes to a large amount of the planet's global warming. An alternative to electric energy generation is the use of polymeric membrane fuel cells (PEMFC), which enable the use of alternative fuels such as hydrogen. This work presents the start-up of a system consisting of a photovoltage cell, an electrolyzer and a PEMFC. The photovoltage cell transforms the solar energy into electric energy which electrolyzes the water to provide hydrogen (fuel) and oxygen (combustion). An electrolyzer was designed and built and was characterized with polarization tests. The gases obtained from the electrolyzer are fed to the fuel cell designed and built in the laboratory. To apply this work, the energy produced in the fuel cell is fed to a low-power device such as the electrical charge of a mobile phone. The integration of electrochemical devices will completely revolutionize today's energy sources, which are based on oil derivatives. These integrated systems are efficient for producing electric energy without emitting gas pollutants. [Spanish] Con el crecimiento de la poblacion mundial, (cercana a 6.3 miles de millones de habitantes en el mundo), se incrementa considerablemente la demanda de energia para cubrir las necesidades energeticas propias y del desarrollo de un pais. El petroleo y el carbon son los combustibles mas empleados en la actualidad para la generacion de energia. Sin embargo, su extraccion y transporte ademas de su combustion traen como consecuencia la produccion de residuos contaminantes, como el bioxido

The small serine-threonine protein SIP2 interacts with STE12 and is involved in ascospore germination in Sordaria macrospora.

Science.gov (United States)

Elleuche, Skander; Bernhards, Yasmine; Schäfers, Christian; Varghese, Jans Manjali; Nolting, Nicole; Pöggeler, Stefanie

2010-12-01

In fungi, the homoeodomain protein STE12 controls diverse developmental processes, and derives its regulatory specificity from different protein interactions. We recently showed that in the homothallic ascomycete Sordaria macrospora, STE12 is essential for ascospore development, and is able to interact with the alpha-domain mating-type protein SMTA-1 and the MADS box protein MCM1. To further evaluate the functional roles of STE12, we used the yeast two-hybrid approach to identify new STE12-interacting partners. Using STE12 as bait, a small, serine-threonine-rich protein (designated STE12-interacting protein 2, SIP2) was identified. SIP2 is conserved among members of the fungal class Sordariomycetes. In vivo localization studies revealed that SIP2 was targeted to the nucleus and cytoplasm. The STE12/SIP2 interaction was further confirmed in vivo by bimolecular fluorescence complementation. Nuclear localization of SIP2 was apparently mediated by STE12. Unlike deletion of ste12, deletion of sip2 in S. macrospora led to only a slight decrease in ascospore germination, and no other obvious morphological phenotype. In comparison to the Δste12 single knockout strain, ascospore germination was significantly increased in a Δsip2/ste12 double knockout strain. Our data provide evidence for a regulatory role of the novel fungal protein SIP2 in ascospore germination. Copyright © 2010 Elsevier GmbH. All rights reserved.

Divergent Evolution of the Transcriptional Network Controlled by Snf1-Interacting Protein Sip4 in Budding Yeasts.

Directory of Open Access Journals (Sweden)

Constance Mehlgarten

Full Text Available Cellular responses to starvation are of ancient origin since nutrient limitation has always been a common challenge to the stability of living systems. Hence, signaling molecules involved in sensing or transducing information about limiting metabolites are highly conserved, whereas transcription factors and the genes they regulate have diverged. In eukaryotes the AMP-activated protein kinase (AMPK functions as a central regulator of cellular energy homeostasis. The yeast AMPK ortholog SNF1 controls the transcriptional network that counteracts carbon starvation conditions by regulating a set of transcription factors. Among those Cat8 and Sip4 have overlapping DNA-binding specificity for so-called carbon source responsive elements and induce target genes upon SNF1 activation. To analyze the evolution of the Cat8-Sip4 controlled transcriptional network we have compared the response to carbon limitation of Saccharomyces cerevisiae to that of Kluyveromyces lactis. In high glucose, S. cerevisiae displays tumor cell-like aerobic fermentation and repression of respiration (Crabtree-positive while K. lactis has a respiratory-fermentative life-style, respiration being regulated by oxygen availability (Crabtree-negative, which is typical for many yeasts and for differentiated higher cells. We demonstrate divergent evolution of the Cat8-Sip4 network and present evidence that a role of Sip4 in controlling anabolic metabolism has been lost in the Saccharomyces lineage. We find that in K. lactis, but not in S. cerevisiae, the Sip4 protein plays an essential role in C2 carbon assimilation including induction of the glyoxylate cycle and the carnitine shuttle genes. Induction of KlSIP4 gene expression by KlCat8 is essential under these growth conditions and a primary function of KlCat8. Both KlCat8 and KlSip4 are involved in the regulation of lactose metabolism in K. lactis. In chromatin-immunoprecipitation experiments we demonstrate binding of both, KlSip4 and

POWER CONTROL OF A BIDIRECTIONAL DC BUS FOR FUEL CELLS APPLICATIONS CONTROL DE POTENCIA DE UN BUS DC BIDIRECCIONAL PARA APLICACIONES DE PILAS DE COMBUSTIBLE CONTROLE DE POTÊNCIA DE UM ÔNIBUS DC BIDIRECIONAL PARA APLICAÇÕES DE PILHAS DE COMBUSTÍVE

Directory of Open Access Journals (Sweden)

Andrés Fernando Restrepo

2012-12-01

Full Text Available This paper proposes a power system for fuel cell applications able to transfer energy from the power source to the load, and to charge an auxiliary storage device using regenerative power flows generated by the load. The solution is based on a closed loop bidirectional DC/DC converter, where additional devices have been also designed to experimentally test the solution in a safe and realistic environment: a fuel cell emulator and an electronic load.Este artículo propone un sistema de potencia para aplicaciones de pilas de combustible capaz de transferir energía de la fuente de potencia a la carga y de cargar un sistema de almacenamiento con flujos regenerativos de potencia desde la carga. La solución está basada en un convertidor bidireccional DC/DC en lazo cerrado. Además, se presentan dispositivos auxiliares diseñados para evaluar experimentalmente la solución en un entorno seguro y realista: un emulador de pila de combustible y una carga electrónica.Este artigo propõe um sistema de potência para aplicações de pilhas de combustível capaz de transferir energia da fonte de potência à carga e de carregar um sistema de armazenamento com fluxos regenerativos de potência desde a carga. A solução está baseada em um conversor bidirecional DC/DC em laço fechado. Ademais, apresentam-se dispositivos auxiliares desenhados para avaliar experimentalmente a solução em um meio seguro e realista: um emulador de pilha de combustível e uma carga eletrônica.

Louisiana SIP: LAC 33:III Ch 2132. Stage II Vapor Recovery Systems for Control of Vehicle Refuelling Emissions at Gasoline Dispensing Facilities; SIP effective 2011-08-04 (LAd34) and 2016-02-29 (LAd47) to 2017-09-27

Science.gov (United States)

Louisiana SIP: LAC 33:III Ch 2132. Stage II Vapor Recovery Systems for Control of Vehicle Refuelling Emissions at Gasoline Dispensing Facilities; SIP effective 2011-08-04 (LAd34) and 2016-02-29 (LAd47) to 2017-09-27

77 FR 24843 - Approval and Promulgation of Air Quality Implementation Plans; Virginia; Removal of...

Science.gov (United States)

2012-04-26

... NO X . These source categories included large fossil fuel-fired electric generating units (EGUs...), large stationary internal combustion engines, and large cement kilns. The NO X SIP Call was challenged... internal combustion engines and large cement kilns. EPA approved Virginia's Phase I NO X SIP Call...

Covert Channels in SIP for VoIP Signalling

Science.gov (United States)

Mazurczyk, Wojciech; Szczypiorski, Krzysztof

In this paper, we evaluate available steganographic techniques for SIP (Session Initiation Protocol) that can be used for creating covert channels during signaling phase of VoIP (Voice over IP) call. Apart from characterizing existing steganographic methods we provide new insights by introducing new techniques. We also estimate amount of data that can be transferred in signalling messages for typical IP telephony call.

Infrastructure of the hydrogen use and materials for fuel cells: key for its soon use; Infraestructura de uso de hidrogeno y materiales para celdas de combustible: clave para su pronto uso

Energy Technology Data Exchange (ETDEWEB)

Cano Castillo, Ulises; Rejon Garcia, Leonardo; Ojeda Hernandez, Mirna [Instituto de Investigaciones Electricas, Temixco, Morelos (Mexico)

2000-07-01

Nowadays, many products for the personal generation of electrical energy exist, such as the batteries and the of internal combustion machines; that have developed and established the infrastructure required for their manufacture, distribution and commercial use. Nevertheless, disadvantages as well as practical limitations and their relationship with the environment exist. The fuel cells are able to increase their applications, as well as to solve practical and environmental challenges, but still they face challenges related to the initial cost and the infrastructure required for their uses. In this article the materials and the fuel cells (PEM) are described (membrane cells of proton interchange or of polymeric membrane electrolyte), of the proton interchanging membrane, gas diffuser, current collector plates of with fields gas flow fields and electrocatalizers. A table of fuel cells applications is shown according to the type of cell from a power of less than 1 KW to greater than 1 MW. Also there is a table of hydrogen production methods and tables where it is represented the hydrogen route in a PEM cell and the basic components of a type PEM fuel cell. In the article appears a table where a comparison of some properties of current collector plates is shown, as well as a graph of the spectra of electrochemical impedances. [Spanish] Hoy en dia, existen muchos productos para la generacion personal de energia electrica, como las baterias y las maquinas de combustion interna; que han desarrollado y establecido la infraestructura requerida para su fabricacion, distribucion y su uso comercial. Sin embargo, existen desventajas en cuanto a limitaciones practicas y su relacion con el ambiente. Las celdas de combustion son capaces de aumentar sus aplicaciones, asi como resolver retos practicos y ambientales, pero asi enfrentan retos relacionados con el costo inicial y las infraestructura requerida para su usos. En este articulo se describen los materiales y la descripcion

Research reactor fuel bundle design review by means of hydrodynamic testing; Ensayos hidrodinamicos para verificacion de diseno de un elemento combustible para reactores de investigacion

Energy Technology Data Exchange (ETDEWEB)

Pastorini, A; Belinco, C [Comision Nacional de Energia Atomica, San Martin (Argentina). Centro Atomico Constituyentes

1998-12-31

During the design steps of a fuel bundle for a nuclear reactor, some vibration tests are usually necessary to verify the prototype dynamical response characteristics and the structural integrity. To perform these tests, the known hydrodynamic loop facilities are used to evaluate the vibrational response of the bundle under the different flow conditions that may appear in the reactor. This paper describes the tests performed on a 19 plate fuel bundle prototype designed for a low power research reactor. The tests were done in order to know the dynamical characteristics of the plates and also of the whole bundle under different flow rate conditions. The paper includes a description of the test facilities and the results obtained during the dynamical characterization tests and some preliminary comments about the tests under flowing water are also presented. (author) 4 refs., 12 figs., 4 tabs. [Espanol] Durante el diseno de un elemento combustible para un reactor nuclear se requiere de la realizacion de ensayos con el objeto de verificar el comportamiento de ese diseno y permitir, de ser necesario, la introduccion de modificaciones al mismo. Para verificar las caracteristicas de respuesta dinamica e integridad estructural, se realizan ensayos de vibraciones que incluyen someter al prototipo a condiciones de circulacion del fluido similares a las que soportara durante la operacion del reactor. Estos ensayos se realizan en facilidades de ensayos conocidas como circuitos hidrodinamicos, que permiten no solo someter el prototipo al flujo de fluido, sino tambien obtener una adecuada caracterizacion de la respuesta del mismo a traves del luso de sensores de distinto tipo. En este trabajo se describen los ensayos realizados sobre un prototipo de elemento combustible de 19 placas destinado a un reactor de investigacion multiproposito de baja potencia. Los ensayos tuvieron como objetivo conocer la respuesta dinamica de las placas individuales y del elemento combustible en su

Cooperation of technical support organizations of state nuclear regulatory committee of Ukraine in sip safety regulation

International Nuclear Information System (INIS)

Bikov, V.O.; Kyilochits'ka, T.P.; Bogorins'kij, P.; Vasil'chenko, V.M.; Kondrat'jev, S.M.; Smishlyajeva, S.P.; Troter, D.

2002-01-01

The main task of the technical support in the Shelter Implementation Plan (SIP) licensing process consists in Technical Evaluation of SIP projects and documents submitted by the Licensee to State Nuclear Regulatory Committee to substantiate the safety of Shelter-related work. The goal of this task is to evaluate the submitted materials whether they meet the requirements of nuclear and radiation safety

Development and implementation of the Caribbean Laboratory Quality Management Systems Stepwise Improvement Process (LQMS-SIP) Towards Accreditation.

Science.gov (United States)

Alemnji, George; Edghill, Lisa; Guevara, Giselle; Wallace-Sankarsingh, Sacha; Albalak, Rachel; Cognat, Sebastien; Nkengasong, John; Gabastou, Jean-Marc

2017-01-01

Implementing quality management systems and accrediting laboratories in the Caribbean has been a challenge. We report the development of a stepwise process for quality systems improvement in the Caribbean Region. The Caribbean Laboratory Stakeholders met under a joint Pan American Health Organization/US Centers for Disease Control and Prevention initiative and developed a user-friendly framework called 'Laboratory Quality Management System - Stepwise Improvement Process (LQMS-SIP) Towards Accreditation' to support countries in strengthening laboratory services through a stepwise approach toward fulfilling the ISO 15189: 2012 requirements. This approach consists of a three-tiered framework. Tier 1 represents the minimum requirements corresponding to the mandatory criteria for obtaining a licence from the Ministry of Health of the participating country. The next two tiers are quality improvement milestones that are achieved through the implementation of specific quality management system requirements. Laboratories that meet the requirements of the three tiers will be encouraged to apply for accreditation. The Caribbean Regional Organisation for Standards and Quality hosts the LQMS-SIP Secretariat and will work with countries, including the Ministry of Health and stakeholders, including laboratory staff, to coordinate and implement LQMS-SIP activities. The Caribbean Public Health Agency will coordinate and advocate for the LQMS-SIP implementation. This article presents the Caribbean LQMS-SIP framework and describes how it will be implemented among various countries in the region to achieve quality improvement.

The role of groundwater discharge fluxes on Si:P ratios in a major tributary to Lake Erie.

Science.gov (United States)

Maavara, Taylor; Slowinski, Stephanie; Rezanezhad, Fereidoun; Van Meter, Kimberly; Van Cappellen, Philippe

2018-05-01

Groundwater discharge can be a major source of nutrients to river systems. Although quantification of groundwater nitrate loading to streams is common, the dependence of surface water silicon (Si) and phosphorus (P) concentrations on groundwater sources has rarely been determined. Additionally, the ability of groundwater discharge to drive surface water Si:P ratios has not been contextualized relative to riverine inputs or in-stream transformations. In this study, we quantify the seasonal dynamics of Si and P cycles in the Grand River (GR) watershed, the largest Canadian watershed draining into Lake Erie, to test our hypothesis that regions of Si-rich groundwater discharge increase surface water Si:P ratios. Historically, both the GR and Lake Erie have been considered stoichiometrically P-limited, where the molar Si:P ratio is greater than the ~16:1 phytoplankton uptake ratio. However, recent trends suggest that eastern Lake Erie may be approaching Si-limitation. We sampled groundwater and surface water for dissolved and reactive particulate Si as well as total dissolved P for 12months within and downstream of a 50-km reach of high groundwater discharge. Our results indicate that groundwater Si:P ratios are lower than the corresponding surface water and that groundwater is a significant source of bioavailable P to surface water. Despite these observations, the watershed remains P-limited for the majority of the year, with localized periods of Si-limitation. We further find that groundwater Si:P ratios are a relatively minor driver of surface water Si:P, but that the magnitude of Si and P loads from groundwater represent a large proportion of the overall fluxes to Lake Erie. Copyright © 2017 Elsevier B.V. All rights reserved.

Proposta de metodologia para classificação de empresas de transporte rodoviário de combustíveis líquidos

Directory of Open Access Journals (Sweden)

Marne Lieggio Júnior

2009-10-01

Full Text Available

O objetivo deste trabalho consiste em propor uma metodologia de classificação de empresas de transporte rodoviário de combustíveis líquidos, de forma a oferecer ao embarcador uma ferramenta de apoio à tomada de decisão, no processo de contratação de uma transportadora. A metodologia de classificação é construída a partir da visão de três grupos de atores: os transportadores de combustível líquido, técnicos da Agência Nacional de Transportes Terrestres – ANTT e especialistas em transporte e logística. Os atributos da oferta de serviço importantes para o transporte rodoviário de combustíveis líquidos levantados junto aos grupos de atores entrevistados deram suporte à elaboração da proposta metodológica.

Combustión y combustibles

Directory of Open Access Journals (Sweden)

Virella, A.

1961-06-01

Full Text Available Not availableLa ponencia trata de los combustibles generalmente empleados en los hornos rotativos de cemento Portland y, especialmente, de los problemas relacionados con los carbones pobres. En cualquier caso, hay que tener un conocimiento previo del poder calorífico del combustible que se pretende emplear, siendo de considerar antes el coste por unidad de calor que el coste por unidad de peso. Se describen el secado y la molienda de los carbones, señalando la tendencia actual de efectuar ambas operaciones simultáneamente, definiendo la aptitud para la pulverización y la determinación de la finura del polvo de carbón, por los métodos clásicos y por medio del permeabilímetro. Se expone en qué medida influyen la finura del combustible, el sistema de inyección, el estado del aire primario, su poder comburente, el exceso de aire y la proporción de cenizas en la determinación de la temperatura de la llama, su poder radiante, el flujo térmico y la posibilidad de obtener un clínker bien cocido. Se propugna por el empleo conjunto de aceites combustibles y carbones pobres como solución muy apropiada en la mayoría de los casos. Por último, se menciona la posibilidad de que se formen anillos en los hornos rotativos como consecuencia del empleo de carbones de alto contenido de cenizas, indicando algunas soluciones para evitar dicha perturbación.

Simulation and analysis of the tangential flow in the combustion chamber of a steam generator; Simulacion y analisis del flujo tangencial en la camara de combustion de un generador de vapor

Energy Technology Data Exchange (ETDEWEB)

Hernandez Ramirez, Isaias

1997-06-01

supplying ducts, were obtained, with a maximum discrepancy of 5.5 m/s between the data published by McKenty and Gravel (1997) and this analysis, for the case of combustion gases in the interior of the furnace. Temperature profiles were obtained, which were overestimated in the order of 417 Celsius degrees for the case of the temperature of gases in the center of the combustion chamber, when comparing them with the corresponding ones obtained by McKenty and Gravel (1997). It is speculated that this discrepancy must to be due to the omission of the connection of the radiation model to the global computational model and; the contours of concentration of species for the combustion products in the chamber were considered (carbon dioxide, oxygen and nitrogen), obtaining only the qualitative behavior of these. It is proposed as conclusion that the computational model developed in this thesis work can be used for the estimation of flow of fluids patterns, heat transference and transference of mass of a steam generator VU-60 of the tangential type and similar to the one taken as a base for this analysis. One improvement to the computational model developed could be achieved including the radiation effect, which requires a larger memory capacity of the computer hardware than the one available during the elaboration of this thesis. [Espanol] El presente trabajo de tesis describe la simulacion y analisis de la camara de combustion de un generador de vapor VU-60 del tipo tangencial, el cual esta basado en la solucion de la ecuacion generalizada de transporte, empleando modelos matematicos desarrollados para la caracterizacion de fenomenos fisicos para cerrar los sistemas de ecuaciones gobernantes. Para la solucion de los modelos matematicos y ecuaciones gobernantes se empleo el metodo de volumen finito, el cual se basa en el concepto de volumen de control. Se desarrollo un modelo computacional tridimensional por medio del cual se estimaron los perfiles de velocidad, presion, temperatura

A single sip of a strong alcoholic beverage causes exposure to carcinogenic concentrations of acetaldehyde in the oral cavity.

Science.gov (United States)

Linderborg, Klas; Salaspuro, Mikko; Väkeväinen, Satu

2011-09-01

The aim of this study was to explore oral exposure to carcinogenic (group 1) acetaldehyde after single sips of strong alcoholic beverages containing no or high concentrations of acetaldehyde. Eight volunteers tasted 5 ml of ethanol diluted to 40 vol.% with no acetaldehyde and 40 vol.% calvados containing 2400 μM acetaldehyde. Salivary acetaldehyde and ethanol concentrations were measured by gas chromatography. The protocol was repeated after ingestion of ethanol (0.5 g/kg body weight). Salivary acetaldehyde concentration was significantly higher after sipping calvados than after sipping ethanol at 30s both with (215 vs. 128 μmol/l, psipping of the alcoholic beverages. Carcinogenic concentrations of acetaldehyde are produced from ethanol in the oral cavity instantly after a small sip of strong alcoholic beverage, and the exposure continues for at least 10 min. Acetaldehyde present in the beverage has a short-term effect on total acetaldehyde exposure. Copyright © 2011 Elsevier Ltd. All rights reserved.

Uma Análise da Demanda por Combustíveis Através do Modelo Almost Ideal Demand System para Pernambuco

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Edilberto Tiago de Almeida

Full Text Available Resumo: O mercado de combustíveis tem sido amplamente estudado sob várias perspectivas, desde a questão da assimetria e transmissão de preços, formação de cartéis, dinâmica de preços atrelada às flutuações na economia internacional, sistemas de demanda, entre outras. Neste sentido, este artigo tem como objetivo estimar um sistema de demanda para gasolina comum, etanol hidratado e óleo diesel via modelo (LA-AIDS Linear Approximation Almost Ideal Demand System com dados de séries temporais trimestrais para o período de 2001 a 2015 para o estado de Pernambuco. As estimações foram feitas por meio do método (SUR Seemingly Unrelated Regressions. Os resultados encontrados são semelhantes aos observados na literatura, no sentido em que apontam para a inelasticidade-preço da demanda da gasolina e diesel, o que é esperado dada a essencialidade dos bens. Também foi possível verificar que a demanda por etanol é elástica por ter elasticidade-preço marshalliana maior que um em valor absoluto, convergindo para os resultados já encontrados em outros estudos.

Telescope sipping the optimum fuel leak detection system

International Nuclear Information System (INIS)

Deleryd, R.

1998-01-01

The TELESCOPE Sipping technology is an evolutionary development from previous ABB fuel leak systems used in LWR reactors. The system utilizes the existing dynamics that cause numerous fission products to leak from a failed fuel rod when the fuel assembly is raised from a reactor core during core fuel alterations. The system can also be used by repair work in pool side inspection in order to detect leaking rods or to verify reconstituted assemblies as non leakers. (author)

Louisiana SIP: LAC 33:III Ch. 7 - Table 2 - Ambient Air--Methods of Contaminant Measurements; SIP effective 1989-05-08 (LAc49) and 1989-08-14 (LAc50) to 2011-08-03 (LAd34 - Moved to Section 711 and revised [adds PM-2.5])

Science.gov (United States)

Louisiana SIP: LAC 33:III Ch. 7 - Table 2 - Ambient Air--Methods of Contaminant Measurements; SIP effective 1989-05-08 (LAc49) and 1989-08-14 (LAc50) to 2011-08-03 (LAd34 - Moved to Section 711 and revised [adds PM-2.5])

Targeting Unknowns Just Underfoot: Microbial Ecology and Community Genomics of C Cycling in Soil Informed and Enabled with DNA-SIP

Science.gov (United States)

Pepe-Ranney, C. P.; Campbell, A.; Buckley, D. H.

2015-12-01

Microorganisms drive biogeochemical cycles and because soil is a large global carbon (C) reservoir (soil contains more C than plants and the atmosphere combined), soil microorganisms are important players in the global C-cycle. Frustratingly, however, many soil microorganisms resist cultivation and soil communities are astoundingly complex. This makes soil microbiology difficult to study and without a solid understanding of soil microbial ecology, models of soil C feedbacks to climate change are under-informed. Stable isotope probing (SIP) is a useful approach for establishing identity-function connections in microbial communities but has been challenging to employ in soil due to the inadequate resolution of microbial community fingerprinting techniques. High throughput DNA sequencing improves SIP resolving power transforming it into a powerful tool for studying the soil C cycle. We conducted a DNA-SIP experiment to track flow of xylose-C, a labile component of plant biomass, and cellulose-C, the most abundant global biopolymer, through a soil microbial community. We could track 13C into microbial DNA even when added 13C amounted to less than 5% of native C and found Spartobacteria, Chloroflexi, and Planctomycetes taxa were among those that assimilated 13C cellulose. These lineages are cosmopolitan in soil but little is known of their ecophysiology. By profiling SSU rRNA genes across entire DNA-SIP density gradients, we assessed relative DNA atom % 13C per taxon in 13C treatments and found cellulose degraders exhibited signal consistent with a specialist lifestyle with respect to C preference. Further, DNA-SIP enriches DNA of targeted microorganisms (Verrucomicrobia cellulose degraders were enriched by nearly two orders of magnitude) and this enriched DNA can serve as template for community genomics. We produced draft genomes from soil cellulose degraders including microorganisms belonging to Verrucomicrobia, Chloroflexi, and Planctomycetes from SIP enriched DNA

Joint inversion of NMR and SIP data to estimate pore size distribution of geomaterials

Science.gov (United States)

Niu, Qifei; Zhang, Chi

2018-03-01

There are growing interests in using geophysical tools to characterize the microstructure of geomaterials because of the non-invasive nature and the applicability in field. In these applications, multiple types of geophysical data sets are usually processed separately, which may be inadequate to constrain the key feature of target variables. Therefore, simultaneous processing of multiple data sets could potentially improve the resolution. In this study, we propose a method to estimate pore size distribution by joint inversion of nuclear magnetic resonance (NMR) T2 relaxation and spectral induced polarization (SIP) spectra. The petrophysical relation between NMR T2 relaxation time and SIP relaxation time is incorporated in a nonlinear least squares problem formulation, which is solved using Gauss-Newton method. The joint inversion scheme is applied to a synthetic sample and a Berea sandstone sample. The jointly estimated pore size distributions are very close to the true model and results from other experimental method. Even when the knowledge of the petrophysical models of the sample is incomplete, the joint inversion can still capture the main features of the pore size distribution of the samples, including the general shape and relative peak positions of the distribution curves. It is also found from the numerical example that the surface relaxivity of the sample could be extracted with the joint inversion of NMR and SIP data if the diffusion coefficient of the ions in the electrical double layer is known. Comparing to individual inversions, the joint inversion could improve the resolution of the estimated pore size distribution because of the addition of extra data sets. The proposed approach might constitute a first step towards a comprehensive joint inversion that can extract the full pore geometry information of a geomaterial from NMR and SIP data.

The atomization and the flame structure in the combustion of residual fuel oils; La atomizacion y estructura de flama en la combustion de combustibles residuales

Energy Technology Data Exchange (ETDEWEB)

Bolado Estandia, Ramon [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

1986-12-31

In this article a research on the combustion of heavy residual fuel oils is presented. The type of flames studied were obtained by means of the burning of sprays produced by an atomizer designed and calibrated specially for the research purpose. The flame characteristics that were analyzed are its length, its luminosity, the temperature, the distribution of the droplets size and mainly the burning regime of the droplets in the flame. The experimental techniques that were used for these studies were shadow micro-photography, suction pyrometry and of total radiation, laser diffraction, 35 mm photography, and impact push. The analysis of the experimental results, together with the results of the application of a mathematical model, permitted to establish two parameters, that quantitatively related determine the burning regime of the droplets in a flame of sprays of residual heavy fuel oil. [Espanol] En este articulo se presenta una investigacion sobre la combustion de combustibles residuales pesados. El tipo de flamas estudiadas se obtuvieron mediante el quemado de sprays producidos por un atomizador disenado y calibrado especialmente para el proposito de la investigacion. Las caracteristicas de flama que se analizaron son la longitud, la luminosidad, la temperatura, la distribucion de tamano de gotas y, principalmente, el regimen de quemado de gotas en la flama. Las tecnicas experimentales que se usaron para estos estudios fueron microfotografia de sombras, pirometria de succion y de radiacion total, difraccion laser, fotografia de 35 mm y empuje de impacto. El analisis de resultados experimentales, junto con los resultados de la aplicacion de un modelo matematico, permitio establecer dos parametros, que relacionados cuantitativamente, determinan el regimen de quemado de gotas en una flama de sprays de combustible residual pesado.

The atomization and the flame structure in the combustion of residual fuel oils; La atomizacion y estructura de flama en la combustion de combustibles residuales

Energy Technology Data Exchange (ETDEWEB)

Bolado Estandia, Ramon [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

1985-12-31

In this article a research on the combustion of heavy residual fuel oils is presented. The type of flames studied were obtained by means of the burning of sprays produced by an atomizer designed and calibrated specially for the research purpose. The flame characteristics that were analyzed are its length, its luminosity, the temperature, the distribution of the droplets size and mainly the burning regime of the droplets in the flame. The experimental techniques that were used for these studies were shadow micro-photography, suction pyrometry and of total radiation, laser diffraction, 35 mm photography, and impact push. The analysis of the experimental results, together with the results of the application of a mathematical model, permitted to establish two parameters, that quantitatively related determine the burning regime of the droplets in a flame of sprays of residual heavy fuel oil. [Espanol] En este articulo se presenta una investigacion sobre la combustion de combustibles residuales pesados. El tipo de flamas estudiadas se obtuvieron mediante el quemado de sprays producidos por un atomizador disenado y calibrado especialmente para el proposito de la investigacion. Las caracteristicas de flama que se analizaron son la longitud, la luminosidad, la temperatura, la distribucion de tamano de gotas y, principalmente, el regimen de quemado de gotas en la flama. Las tecnicas experimentales que se usaron para estos estudios fueron microfotografia de sombras, pirometria de succion y de radiacion total, difraccion laser, fotografia de 35 mm y empuje de impacto. El analisis de resultados experimentales, junto con los resultados de la aplicacion de un modelo matematico, permitio establecer dos parametros, que relacionados cuantitativamente, determinan el regimen de quemado de gotas en una flama de sprays de combustible residual pesado.

Estudio comparativo de las diferentes tecnologías de celdas de combustible

Directory of Open Access Journals (Sweden)

Alvarado-Flores, J.

2013-06-01

Full Text Available Fuel cells generate electricity and heat during electrochemical reaction which happens between the oxygen and hydrogen to form the water. Fuel cell technology is a promising way to provide energy for rural areas where there is no access to the public grid or where there is a huge cost of wiring and transferring electricity. In addition, applications with essential secure electrical energy requirement such as uninterruptible power supplies (UPS, power generation stations and distributed systems can employ fuel cells as their source of energy. The current paper includes a comparative study of basic design, working principle, applications, advantages and disadvantages of various technologies available for fuel cells. In addition, techno-economic features of hydrogen fuel cell vehicles (FCV and internal combustion engine vehicles (ICEV are compared. The results indicate that fuel cell systems have simple design, high reliability, noiseless operation, high efficiency and less environmental impact. The aim of this paper is to serve as a convenient reference for fuel cell power generation reviews.Las celdas de combustible generan electricidad y calor durante la reacción electroquímica que ocurre entre el oxígeno e hidrógeno para formar agua. La tecnología de la celda de combustible es un camino prometedor para proporcionar energía en áreas rurales, donde no hay acceso a la red eléctrica pública, o donde hay un costo enorme en el cableado y transferencia de electricidad. Además, las celdas de combustible, pueden emplearse como fuente de energía, para asegurar la energía eléctrica como por ejemplo, en fuentes de potencia ininterrumpida (uninterruptible power supplies, UPS, estaciones de generación de energía y sistemas de distribución. En este artículo, se hace un estudio comparativo sobre diseño básico, principios de funcionamiento, aplicaciones, ventajas y desventajas de las diversas tecnologías disponibles para celdas de

Tolerancia al co en celdas de combustible

Directory of Open Access Journals (Sweden)

BIBIAN HOYOS

2008-01-01

Full Text Available El entendimiento completo del proceso de adsorción y posterior oxidación de moléculas de CO en platino es de fundamental importancia para el desarrollo de celdas de combustible poliméricas que operan a baja temperatura. En este trabajo se presenta una revisión de las cinco estrategias experimentales más importantes en la búsqueda de mejorar la tolerancia al CO: disminución del potencial de inicio de la reacción de oxidación, reducción de la cantidad de CO adsorbido, utilización de pequeñas cantidades de oxígeno en la corriente de alimentación al ánodo, aumento de la temperatura de operación y limpieza del CO a la entrada. Aunque se han desarrollado catalizadores bastante promisorios (PtMo y PdAu, todavía se sigue considerando a la mezcla Pt-Ru como el catalizador anódico más eficiente para combustibles que contienen 10 ppm de CO o más. La estrategia de inyectar oxígeno al ánodo parece promisoria pero requiere el desarrollo de nuevas membranas más resistentes y de la implementación de condiciones más seguras de operación de la celda. El diseño estructural de ánodos especiales con múltiples capas soportando catalizadores específicos para cada tipo de combustible puede ser una estrategia muy atractiva.

Uso de elementos de tierras raras contenidos en los discos duros de computadoras para optimizar la quema de combustibles fluidos

Directory of Open Access Journals (Sweden)

Carlos Vallejos

2014-12-01

Full Text Available La investigación examinó el uso de imanes de neodimio provenientes de los discos duros de computadoras en desuso, y su utilización como optimizadores de la combustión de fluidos tales como propano, butano o la mezcla de los mismos. En la validación del efecto del campo magnético sobre los fluidos en referencia se utilizaron dos cocinas nuevas y dos cocinas previamente utilizadas, con su respectiva alimentación de gas. Los ensayos se realizaron sin y con imanes de neodimio provenientes de desechos tecnológicos. Como resultado de la investigación se concluyó que tales imanes son aptos para este propósito, con un rango de optimización en la combustión del gas de entre el 13 y el 20%. Esto pudo demostrarse mediante la aplicación de principios generales de la mecánica de fluidos, del campo magnético y de la termodinámica. Los resultados contribuyen a la búsqueda de estrategias para disminuir el uso de combustibles fosiles en los hogares y otros espacios donde se utiliza gas licuado para la cocción de los alimentos, así cómo para contribuir al bienestar de la microeconomía.

Safety and immunogenicity of an oral DNA vaccine encoding Sip of Streptococcus agalactiae from Nile tilapia Oreochromis niloticus delivered by live attenuated Salmonella typhimurium.

Science.gov (United States)

Huang, L Y; Wang, K Y; Xiao, D; Chen, D F; Geng, Y; Wang, J; He, Y; Wang, E L; Huang, J L; Xiao, G Y

2014-05-01

Attenuated Salmonella typhimurium SL7207 was used as a carrier for a reconstructed DNA vaccine against Streptococcus agalactiae. A 1.02 kb DNA fragment, encoding for a portion of the surface immunogenic protein (Sip) of S. agalactiae was inserted into pVAX1. The recombinant plasmid pVAX1-sip was transfected in EPC cells to detect the transient expression by an indirect immunofluorescence assay, together with Western blot analysis. The pVAX1-sip was transformed by electroporation into SL7207. The stability of pVAX1-sip into Salmonella was over 90% after 50 generations with antibiotic selection in vitro while remained stable over 80% during 35 generations under antibiotic-free conditions. The LD50 of SL/pVAX1-sip was 1.7 × 10(11) CFU/fish by intragastric administration which indicated a quite low virulence. Tilapias were inoculated orally at 10(8) CFU/fish, the recombinant bacteria were found present in intestinal tract, spleens and livers and eventually eliminated from the tissues 4 weeks after immunization. Fish immunized at 10(7), 10(8) and 10(9) CFU/fish with different immunization times caused various levels of serum antibody and an effective protection against lethal challenge with the wild-type strain S. agalactiae. Integration studies showed that the pVAX1-sip did not integrate with tilapia chromosomes. The DNA vaccine SL/pVAX1-sip was proved to be safe and effective in protecting tilapias against S. agalactiae infection. Copyright © 2014 Elsevier Ltd. All rights reserved.

Herramienta flexible para análisis de estabilidad de pequeña señal

OpenAIRE

Biteznik, Carlos Ezequiel; Agüero, Jorge Luis; Beroqui, Mario César

2015-01-01

El análisis modal permite determinar los autovalores o modos de oscilación de un sistema, expresados en términos de frecuencia y amortiguamiento. Para el realizar el análisis modal, se requiere la matriz "A" de estado del sistema. En estudios llevados a cabo sobre el Sistema Argentino de Interconexión y Sistema Interconectado Patagónico (SADI-SIP), la matriz de estado se obtiene de los mismos modelos no lineales utilizados para estudios de estabilidad transitoria. La base de datos de model...

78 FR 68005 - Approval and Promulgation of Implementation Plans; Mississippi; Transportation Conformity SIP...

Science.gov (United States)

2013-11-13

...] Approval and Promulgation of Implementation Plans; Mississippi; Transportation Conformity SIP--Memorandum... transportation conformity criteria and procedures related to interagency consultation and enforceability of... conformity process to allow direct consultation among agencies at the Federal, state and local levels. This...

The Impact of Dopant Segregation on the Maximum Carrier Density in Si:P Multilayers.

Science.gov (United States)

Keizer, Joris G; McKibbin, Sarah R; Simmons, Michelle Y

2015-07-28

Abrupt dopant profiles and low resistivity are highly sought after qualities in the silicon microelectronics industry and, more recently, in the development of an all epitaxial Si:P based quantum computer. If we increase the active carrier density in silicon to the point where the material becomes superconducting, while maintaining a low thermal budget, it will be possible to fabricate nanoscale superconducting devices using the highly successful technique of depassivation lithography. In this work, we investigate the dopant profile and activation in multiple high density Si:P δ-layers fabricated by stacking individual layers with intervening silicon growth. We determine that dopant activation is ultimately limited by the formation of P-P dimers due to the segregation of dopants between multilayers. By increasing the encapsulation thickness between subsequent layers, thereby minimizing the formation of these deactivating defects, we are able to achieve an active carrier density of ns = 4.5 ×10(14) cm(-2) for a triple layer. The results of electrical characterization are combined with those of secondary ion mass spectroscopy to construct a model that accurately describes the impact of P segregation on the final active carrier density in Si:P multilayers. Our model predicts that a 3D active carrier density of 8.5 × 10(20) cm(-3) (1.7 atom %) can be achieved.

Biorremediación para la degradación de hidrocarburos totales presentes en los sedimentos de una estación de servicio de combustible

OpenAIRE

Ñústez Cuartas, Diana Cristina; Paredes Cuervo, Diego; Cubillos Vargas, Janneth

2014-01-01

En la presente investigación, se evaluó el efecto de la Bioaumentación y Bioestimulación de los sedimentos contaminados con hidrocarburos (HTP) de una Estación de Servicio de Combustible (EDS), provenientes del mantenimiento de las unidades de tratamiento de aguas residuales industriales, como son: la trampa de grasa, canales perimetrales y desarenador del lavado vehicular. Para el desarrollo del trabajo, se utilizaron ocho mesocosmos, compuestos por canastas de polietileno de alta densidad, ...

Gas de Síntesis como Combustible para la Generación de Energía-Edición Ênica

OpenAIRE

Valdés de León, Osvaldo A.

2005-01-01

El presente trabajo analiza el proceso de gasificación acoplado a un ciclo combinado, con la finalidad de producir energía eléctrica, para lo cual se utilizan como combustibles el carbón, el coque de petróleo y los residuos sólidos municipales. El análisis matemático se realiza a través de la modelación de las ecuaciones químicas y termodinámicas que lo describen. Se resuelve el modelo haciendo variar los parámetros que describen el mecanismo de gasificación (presión, temperatura y los flujos...

Sipping test on a failed MTR fuel element

International Nuclear Information System (INIS)

Terremoto, Luis Antonio Albiac; Zeituni, Carlos Alberto; Silva, Antonio Teixeira e; Perrotta, Jose Augusto; Silva, Jose Eduardo Rosa da

2002-01-01

This work describes sipping tests performed on MTR fuel elements of the IEA-R1 research reactor, in order to determinate which one failed in the core during a routine operation of the reactor. radioactive iodine isotopes 131 I and 133 I, employed as failure indicators, were detected in samples corresponding to the fuel element IEA-156. The specific activity of each sample, as well as the average leaking rate, were measured for 137 Cs. The nuclear fuels U 3 O 8 - Al dispersion and U - Al alloy were compared concerning their measured average leaking rates of 137 Cs. (author)

Flux-Enabled Exploration of the Role of Sip1 in Galactose Yeast Metabolism

Directory of Open Access Journals (Sweden)

Christopher M. Shymansky

2017-05-01

Full Text Available 13C metabolic flux analysis (13C MFA is an important systems biology technique that has been used to investigate microbial metabolism for decades. The heterotrimer Snf1 kinase complex plays a key role in the preference Saccharomyces cerevisiae exhibits for glucose over galactose, a phenomenon known as glucose repression or carbon catabolite repression. The SIP1 gene, encoding a part of this complex, has received little attention, presumably, because its knockout lacks a growth phenotype. We present a fluxomic investigation of the relative effects of the presence of galactose in classically glucose-repressing media and/or knockout of SIP1 using a multi-scale variant of 13C MFA known as 2-Scale 13C metabolic flux analysis (2S-13C MFA. In this study, all strains have the galactose metabolism deactivated (gal1Δ background so as to be able to separate the metabolic effects purely related to glucose repression from those arising from galactose metabolism. The resulting flux profiles reveal that the presence of galactose in classically glucose-repressing conditions, for a CEN.PK113-7D gal1Δ background, results in a substantial decrease in pentose phosphate pathway (PPP flux and increased flow from cytosolic pyruvate and malate through the mitochondria toward cytosolic branched-chain amino acid biosynthesis. These fluxomic redistributions are accompanied by a higher maximum specific growth rate, both seemingly in violation of glucose repression. Deletion of SIP1 in the CEN.PK113-7D gal1Δ cells grown in mixed glucose/galactose medium results in a further increase. Knockout of this gene in cells grown in glucose-only medium results in no change in growth rate and a corresponding decrease in glucose and ethanol exchange fluxes and flux through pathways involved in aspartate/threonine biosynthesis. Glucose repression appears to be violated at a 1/10 ratio of galactose-to-glucose. Based on the scientific literature, we may have conducted our experiments

Assessment of SIP Buildings for Sustainable Development in Rural China Using AHP-Grey Correlation Analysis.

Science.gov (United States)

Bai, Libiao; Wang, Hailing; Shi, Chunming; Du, Qiang; Li, Yi

2017-10-25

Traditional rural residential construction has the problems of high energy consumption and severe pollution. In general, with sustainable development in the construction industry, rural residential construction should be aimed towards low energy consumption and low carbon emissions. To help achieve this objective, in this paper, we evaluated four different possible building structures using AHP-Grey Correlation Analysis, which consists of the Analytic Hierarchy Process (AHP) and the Grey Correlation Analysis. The four structures included the traditional and currently widely used brick and concrete structure, as well as structure insulated panels (SIPs). Comparing the performances of economic benefit and carbon emission, the conclusion that SIPs have the best overall performance can be obtained, providing a reference to help builders choose the most appropriate building structure in rural China.

Demanda por gasolina: um estudo de caso para uma rede de postos de combustíveis

Directory of Open Access Journals (Sweden)

Samia Mercado Alvarenga

2017-07-01

Full Text Available RESUMO: Este trabalho tem como objetivo analisar a demanda por gasolina em uma Rede de Postos situada na fronteira oeste do Rio Grande Sul, além disso, pretende-se verificar estatisticamente a existência de sazonalidade nas vendas desse combustível. Para tanto, recorre-se ao estudo de caso apoiado no ferramental econométrico. O período de análise compreende desde janeiro de 2010 a junho de 2016, os dados utilizados são provenientes de fontes secundárias tais como os documentos da empresa e órgãos governamentais. Os principais resultados revelam que a demanda por gasolina é explicada por aumentos na renda e não é estatisticamente afetada pelos preços, sugerindo uma demanda inelástica e uma relação imperfeita de substituição com o álcool. A sazonalidade foi confirmada, validando estudos anteriores.

Experience on wet storage spent fuel sipping at IEA-R1 Brazilian research reactor

International Nuclear Information System (INIS)

Perrotta, J.A.; Terremoto, L.A.A.; Zeituni, C.A.

1998-01-01

The IEA-R1 research reactor of the Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP) is a pool type reactor of B and W design, that has been operating since 1957 at a power of 2 MW. Irradiated (spent) fuels have been stored at the facility during the various years of operation. At present there are 40 spent fuel assemblies at dry storage, 79 spent fuel assemblies at wet storage and 30 fuel assemblies in the core. The oldest fuels are of United States origin, made with U-Al alloy, both of LEU and HEU MTR fuel type. Many of these fuel assemblies have corrosion pits along their lateral fuel plates. These pits originate by galvanic corrosion between the fuel plate and the stainless steel storage racks. As a consequence of the possibility of sending the irradiated old fuels back the U.S.A., sipping tests were performed with the spent fuel assemblies. The reason for this was to evaluate their 137 Cs leaking rate, if any. This work describes the procedure and methodology used to perform the sipping tests with the fuel assemblies at the storage pool, and presents the results obtained for the 137 Cs sipping water activity for each fuel assembly. A correlation is made between the corrosion pits and the activity values measured. A 137 Cs leaking rate is determined and compared to the criteria established for canning spent fuel assemblies before shipment

Scaling of ion implanted Si:P single electron devices

International Nuclear Information System (INIS)

Escott, C C; Hudson, F E; Chan, V C; Petersson, K D; Clark, R G; Dzurak, A S

2007-01-01

We present a modelling study on the scaling prospects for phosphorus in silicon (Si:P) single electron devices using readily available commercial and free-to-use software. The devices comprise phosphorus ion implanted, metallically doped (n + ) dots (size range 50-500 nm) with source and drain reservoirs. Modelling results are compared to measurements on fabricated devices and discussed in the context of scaling down to few-electron structures. Given current fabrication constraints, we find that devices with 70-75 donors per dot should be realizable. We comment on methods for further reducing this number

Scaling of ion implanted Si:P single electron devices

Energy Technology Data Exchange (ETDEWEB)

Escott, C C [Centre for Quantum Computer Technology, School of Electrical Engineering and Telecommunications, UNSW, Sydney, NSW 2052 (Australia); Hudson, F E [Centre for Quantum Computer Technology, School of Electrical Engineering and Telecommunications, UNSW, Sydney, NSW 2052 (Australia); Chan, V C [Centre for Quantum Computer Technology, School of Electrical Engineering and Telecommunications, UNSW, Sydney, NSW 2052 (Australia); Petersson, K D [Centre for Quantum Computer Technology, School of Electrical Engineering and Telecommunications, UNSW, Sydney, NSW 2052 (Australia); Clark, R G [Centre for Quantum Computer Technology, School of Physics, UNSW, Sydney, 2052 (Australia); Dzurak, A S [Centre for Quantum Computer Technology, School of Electrical Engineering and Telecommunications, UNSW, Sydney, NSW 2052 (Australia)

2007-06-13

We present a modelling study on the scaling prospects for phosphorus in silicon (Si:P) single electron devices using readily available commercial and free-to-use software. The devices comprise phosphorus ion implanted, metallically doped (n{sup +}) dots (size range 50-500 nm) with source and drain reservoirs. Modelling results are compared to measurements on fabricated devices and discussed in the context of scaling down to few-electron structures. Given current fabrication constraints, we find that devices with 70-75 donors per dot should be realizable. We comment on methods for further reducing this number.

Security Analysis System to Detect Threats on a SIP VoIP Infrasctructure Elements

Directory of Open Access Journals (Sweden)

Filip Rezac

2011-01-01

Full Text Available SIP PBX is definitely the alpha and omega of any IP telephony infrastructure and frequently also provides other services than those related to VoIP traffic. These exchanges are, however, very often the target of attacks by external actors. The article describes a system that was developed on VSB-TU Ostrava as a testing tool to verify if the target VoIP PBX is adequately secured and protected against any real threats. The system tests the SIP element for several usually occurring attacks and it compiles evaluation of its overall security on the basis of successfully or unsuccessfully penetrations. The article describes the applications and algorithms that are used by system and the conclusion consists recommendations and guidelines to ensure effective protection against VoIP PBX threats. The system is designed as an open-source web application, thus allowing independent access and is fully extensible to other test modules.

Non-Destructive Methods for Determining Burn-Up in Nuclear Fuel; Methodes Non Destructives d'Evaluation du Taux de Combustion dans le Combustible Nucleaire; Metody opredeleniya vygoraniya v yadernom toplive bez razrusheniya obraztsa; Metodos No Destructivos para Determinai el Grado de Combustion de los Elementos Combustibles Nucleares

Energy Technology Data Exchange (ETDEWEB)

McGonnagle, W. J. [Illinois Institute of Technology, Chicago, IL (United States)

1966-02-15

gamma emis par les matieres radioactives qui se forment au cours du processus de fission, en particulier le spectrometre a cristal courbe, le spectrometre Compton magnetique, le spectrometre Compton a coiencidence et le spectrometre a scintillation. Parmi les autres methodes non destructives, on peut citer l'activation de feuilles, la transmission des neutrons, l'analyse par activation, la mesure des rayonnements gamma de capture et la mesure des neutrons instantanes et differes. Le memoire etudie les principes essentiels des differents appareils et procedes ci-dessus, leur precision et leurs limitations. Le memoire presente des methodes non destructives utilisant les isotopes stables produits au cours du processus de fission. Dans les mesures au moyen de ces isotopes, le schema d'irradiation n'a qu'une importance secondaire et le temps de refroidissement ne joue aucun role. De plus, on dispose de donnees nucleaires plus precises sur les produits stables de la fission. Il semble que les plus utiles de tous les isotopes stables produits au cours du processus de fission soient ceux du zirconium, du molybdene, du ruthenium et du neodyme. Le memoire etudie l'interet de ces methodes d'analyse non destructive. (author) [Spanish] Los metodos no destructivos son de gran utilidad para medir cuantitativamente el grado de combustion. El metodo ideal seria el que no requiriese datos especiales sobre los espectros neutrtfni- cos, las irradiaciones precedentes o el tiempo de enfriamiento. Los elementos combustibles irradiados llevan en cierto modo el registro de su grado de combustion. Este registro consiste en el conjunto de los isotopos radiactivos y estables resultantes del proceso de fision. Desgraciadamente, tanto con los metodos no destructivos como con los destructivos el espectro neutronico, las irradiaciones precedentes y el tiempo de enfriamiento influyen sobre dicho registro. Analogamente, la falta de datos nucleares precisos tales como las secciones eficaces nucleares

PROCEDIMIENTO PARA LA MEJORA PROCESOS QUE INTERVIENEN EN EL CONSUMO DE COMBUSTIBLE

Directory of Open Access Journals (Sweden)

Liodine Miyashiro Pérez

2009-09-01

Full Text Available

El ahorro de combustible es una necesidad devenida por su agotamiento previsible, la inestabilidad en sus precios y el impacto ambiental que causa su uso continuado. El mundo ha desarrollado varias políticas de contención, entre las cuales se incluye el incremento máximo de la eficiencia en el uso de todas las formas de energía. La mejora continua de procesos y de los indicadores que caracterizan el consumo de combustible, a través de un procedimiento estructurado, que permita el alcance paulatino de este objetivo, es la propuesta que se presenta en este artículo. El procedimiento se aplica al proceso de gestión de combustible de la base de transporte, de la Universidad de las Ciencias Informáticas (UCI y se obtiene una mejora en los indicadores de eficiencia y eficacia definidos.

Coupled RNA-SIP and metatranscriptomics of active chemolithoautotrophic communities at a deep-sea hydrothermal vent.

Science.gov (United States)

Fortunato, Caroline S; Huber, Julie A

2016-08-01

The chemolithoautotrophic microbial community of the rocky subseafloor potentially provides a large amount of organic carbon to the deep ocean, yet our understanding of the activity and metabolic complexity of subseafloor organisms remains poorly described. A combination of metagenomic, metatranscriptomic, and RNA stable isotope probing (RNA-SIP) analyses were used to identify the metabolic potential, expression patterns, and active autotrophic bacteria and archaea and their pathways present in low-temperature hydrothermal fluids from Axial Seamount, an active submarine volcano. Metagenomic and metatranscriptomic results showed the presence of genes and transcripts for sulfur, hydrogen, and ammonium oxidation, oxygen respiration, denitrification, and methanogenesis, as well as multiple carbon fixation pathways. In RNA-SIP experiments across a range of temperatures under reducing conditions, the enriched (13)C fractions showed differences in taxonomic and functional diversity. At 30 °C and 55 °C, Epsilonproteobacteria were dominant, oxidizing hydrogen and primarily reducing nitrate. Methanogenic archaea were also present at 55 °C, and were the only autotrophs present at 80 °C. Correspondingly, the predominant CO2 fixation pathways changed from the reductive tricarboxylic acid (rTCA) cycle to the reductive acetyl-CoA pathway with increasing temperature. By coupling RNA-SIP with meta-omics, this study demonstrates the presence and activity of distinct chemolithoautotrophic communities across a thermal gradient of a deep-sea hydrothermal vent.

78 FR 22827 - Approval and Promulgation of Implementation Plans; State of Kansas; Infrastructure SIP...

Science.gov (United States)

2013-04-17

... strategies to reduce air pollution. Based upon review of the state's infrastructure SIP submissions for the... revisions; (I) Nonattainment areas; (J) Consultation with government officials, public notification... pollution with the Secretary of Health and Environment (``Secretary''). The Secretary in turn administers...

Álcool combustível no Brasil e path dependence

Directory of Open Access Journals (Sweden)

Pery Francisco Assis Shikida

2012-06-01

Full Text Available Este trabalho tem como objetivo analisar a relação de path dependence no sistema econômico e institucional do álcool combustível no Brasil. O etanol, após fases de crescimento e desafios, tornou-se parte da matriz energética brasileira. Esta trajetória reflete a persistência de uma rota (caminho traçada sob influência de organizações (usinas e destilarias, setor de máquinas e equipamentos, indústria automobilística, Estado, organizações corporativistas, P&D e de agentes econômicos (consumidores voltados, direta ou indiretamente, para a manutenção dessa rota escolhida. Este arranjo de "interesses" deu sustentação ao etanol brasileiro, mesmo em momentos em que a competitividade deste combustível era questionada como opção energética mais adequada para a substituição de gasolina/ diesel. Mesmo após a retomada do setor nos anos 2000, em que a tecnologia flex e as crescentes preocupações acerca das mudanças climáticas impulsionaram o setor no Brasil e no mundo, a escolha do etanol como substituto dos derivados do petróleo ainda se mostra ameaçada por novas tecnologias renováveis e mesmo pela descoberta de novas reservas de petróleo. Fica claro que, caso se deseje manter a liderança no mercado nacional de combustíveis e expandir o mercado internacional para estes produtos, a coalizão em torno do álcool combustível ainda precisará enfrentar diversas questões técnicas e institucionais.

eSIP: A Novel Solution-Based Sectioned Image Property Approach for Microscope Calibration.

Directory of Open Access Journals (Sweden)

Malte Butzlaff

Full Text Available Fluorescence confocal microscopy represents one of the central tools in modern sciences. Correspondingly, a growing amount of research relies on the development of novel microscopic methods. During the last decade numerous microscopic approaches were developed for the investigation of various scientific questions. Thereby, the former qualitative imaging methods became replaced by advanced quantitative methods to gain more and more information from a given sample. However, modern microscope systems being as complex as they are, require very precise and appropriate calibration routines, in particular when quantitative measurements should be compared over longer time scales or between different setups. Multispectral beads with sub-resolution size are often used to describe the point spread function and thus the optical properties of the microscope. More recently, a fluorescent layer was utilized to describe the axial profile for each pixel, which allows a spatially resolved characterization. However, fabrication of a thin fluorescent layer with matching refractive index is technically not solved yet. Therefore, we propose a novel type of calibration concept for sectioned image property (SIP measurements which is based on fluorescent solution and makes the calibration concept available for a broader number of users. Compared to the previous approach, additional information can be obtained by application of this extended SIP chart approach, including penetration depth, detected number of photons, and illumination profile shape. Furthermore, due to the fit of the complete profile, our method is less susceptible to noise. Generally, the extended SIP approach represents a simple and highly reproducible method, allowing setup independent calibration and alignment procedures, which is mandatory for advanced quantitative microscopy.

SIP-Based Single Neuron Stochastic Predictive Control for Non-Gaussian Networked Control Systems with Uncertain Metrology Delays

Directory of Open Access Journals (Sweden)

Xinying Xu

2018-06-01

Full Text Available In this paper, a novel data-driven single neuron predictive control strategy is proposed for non-Gaussian networked control systems with metrology delays in the information theory framework. Firstly, survival information potential (SIP, instead of minimum entropy, is used to formulate the performance index to characterize the randomness of the considered systems, which is calculated by oversampling method. Then the minimum values can be computed by optimizing the SIP-based performance index. Finally, the proposed strategy, minimum entropy method and mean square error (MSE are applied to a networked motor control system, and results demonstrated the effectiveness of the proposed strategy.

75 FR 32190 - Disease, Disability, and Injury Prevention and Control Special Interest Projects (SIPs...

Science.gov (United States)

2010-06-07

... DEPARTMENT OF HEALTH AND HUMAN SERVICES Centers for Disease Control and Prevention Disease, Disability, and Injury Prevention and Control Special Interest Projects (SIPs): Examining the Impact of... Advisory Committee Act (Pub. L. 92-463), the Centers for Disease Control and Prevention (CDC) announces the...

Estudio de la deposición de catalizador sobre membranas de intercambio protónico basadas en líquidos iónicos polimerizados para su aplicación en pilas de combustible

OpenAIRE

Herrero Rozas, Luis Alberto

2017-01-01

RESUMEN: Debido al aumento de la población mundial y a los problemas asociados al cambio climático se están desarrollando nuevas fuentes de energía más sostenibles. Crabtree y cols (2006) propusieron un modelo energético basado en la producción de hidrógeno a partir de energías renovables y su almacenamiento para su posterior uso. En este modelo energético las pilas de combustible juegan un papel fundamental al ser las generadoras de energía eléctrica. Una pila de combustible es un dispos...

78 FR 2871 - Approval and Promulgation of Implementation Plans; Georgia: New Source Review-Prevention of...

Science.gov (United States)

2013-01-14

... management processes; CO 2 from the combustion of biogas collected from biological decomposition of waste in... provision at (i)(4) provide exemptions from the requirement of a source to obtain a SIP permit for... regarding testing and monitoring, and changes regarding exemptions from the requirement to obtain a SIP...

Combustion and gasification of solid biomass: energy solutions for the Amazon; Combustao e gasificacao de biomassa solida: solucoes energeticas para a Amazonia

Energy Technology Data Exchange (ETDEWEB)

Barreto, Eduardo Jose Fagundes; Rendeiro, Goncalo; Nogueira, Manoel Fernandes Martins; Brasil, Augusto Cesar de Mendonca; Cruz, Daniel Onofre de Almeida; Guerra, Danielle Regina da Silva; Macedo, Emanuel Negrao; Ichihara, Jorge de Araujo

2008-07-01

For electrify isolated rural communities in the Amazon, the Ministerio de Minas e Energia - MME (Brazilian Mining and Energy Ministry), promoted under the 'Luz para todos' (Light for All) program, a series of activities aimed at the development and implementation of projects for small- scale power generation and training professionals, in the region, for the deployment of alternative energy solutions from renewable energy sources. Among these activities are the production of the collection 'Energy Solutions for the Amazon', consisting of five volumes. This is the fourth volume in the series that presents an overview of the combustion and gasification of solid biomass.

77 FR 29351 - Disease, Disability, and Injury Prevention and Control; Special Interest Projects (SIPs): Initial...

Science.gov (United States)

2012-05-17

... DEPARTMENT OF HEALTH AND HUMAN SERVICES Centers for Disease Control and Prevention Disease, Disability, and Injury Prevention and Control; Special Interest Projects (SIPs): Initial Review The meeting.... L. 92-463), the Centers for Disease Control and Prevention (CDC) announces the aforementioned...

Spectral Induced Polarization (SIP) monitoring during Microbial Enhanced Oil Recovery (MEOR)

Science.gov (United States)

Heenan, J. W.; Ntarlagiannis, D.; Slater, L. D.

2010-12-01

Jeffrey Heenan, Dimitrios Ntarlagiannis, Lee Slater Department of Earth and Environmental Sciences, Rutgers University, Newark NJ Microbial Enhanced Oil Recovery (MEOR) is an established, cost effective, method for enhancing tertiary oil recovery. Although not commonly used for shallow heavy oils, it could be a viable alternative since it can offer sustainable economic recovery and minimal environmental impact. A critical component of successful MEOR treatments is accurate, real time monitoring of the biodegradation processes resulting from the injection of microbial communities into the formation; results of recent biogeophysical research suggest that minimally-invasive geophysical methods could significantly contribute to such monitoring efforts. Here we present results of laboratory experiments, to assess the sensitivity of the spectral induced polarization method (SIP) to MEOR treatments. We used heavy oil, obtained from a shallow oilfield in SW Missouri, to saturate three sand columns. We then followed common industry procedures,and used a commercially available microbial consortia, to treat the oil columns. The active MEOR experiments were performed in duplicate while a control column maintained similar conditions, without promoting microbial activity and oil degradation. We monitored the SIP signatures, between 0.001 Hz and 1000 Hz, for a period of six months. To support the geophysical measurements we also monitored common geochemical parameters, including pH, Eh and fluid conductivity, and collected weekly fluid samples from the outflow and inflow for further analysis; fluid samples were analyzed to confirm that microbes actively degraded the heavy oils in the column while destructive analysis of the solid materials was performed upon termination of the experiment. Preliminary analysis of the results suggests that SIP is sensitive to MEOR processes. In both inoculated columns we recorded an increase in the low frequency polarization with time; measureable

Avaliação do desempenho de um aquecedor para aves adaptado para utilizar biogás como combustível Birds heater adaptation and performance using biogas as fuel

Directory of Open Access Journals (Sweden)

Tânia M. B. Santos

2007-12-01

Full Text Available Desenvolveu-se ensaio para avaliar a adaptação (diâmetro do injetor e o desempenho (consumo e eficiência de aquecimento de um aquecedor tipo campânula, adaptado para queimar biogás. Foi testado um aquecedor comum que, queimando gás liquefeito de petróleo (GLP, opera à baixa pressão (28 cm.c.a., com capacidade calorífica de 5.024 kJ h-1 e recomendado para 500 aves. O aquecedor foi avaliado com o combustível original (GLP, sem qualquer modificação no injetor de gás, e após adaptação para o funcionamento a biogás. Na adaptação, foi mantida a mesma grelha do queimador principal, aumentando-se a perfuração do injetor para permitir o funcionamento e a avaliação. Foram avaliados cinco injetores com perfurações de 1,0053; 1,5080; 1,5708; 1,7672 e 1,980 mm². Também se variaram as pressões do biogás na entrada do aquecedor de 10; 12; 15; 17 e 20 cm de coluna d'água (cm.c.a.. Os resultados indicaram que as expressões de cálculo teórico e parâmetros propostos na bibliografia podem ser utilizados com segurança na adaptação de aquecedores do tipo campânula utilizados em aviários; que a adaptação é de simples execução, indicando a viabilidade da utilização dos aquecedores já existentes em granjas e no mercado, e que as temperaturas do ar foram semelhantes às obtidas com o combustível original (GLP.It was carried out a trial to evaluate the adaptation (injector diameter and performance (biogas consumption and heating efficiency of a heating adapted to burn biogas. It was tried a common heater, burning liquefied petroleum gas (LPG, operating with low gas pressure (28 cm water column, with calorific capacity of 5024 kJ/h and recommended for 500 birds. The heater was evaluated with the original fuel (LPG without any modification in the gas injector and after adapting to biogas burning. Five injectors were evaluated with drillings of 1,0053; 1,5080; 1,5708; 1,7672 and 1,980 mm2. It also was varied the biogas

Relevance of phosphorus incorporation and hydrogen removal for Si:P {delta}-doped layers fabricated using phosphine

Energy Technology Data Exchange (ETDEWEB)

Goh, K.E.J.; Oberbeck, L.; Simmons, M.Y. [Centre for Quantum Computer Technology, School of Physics, The University of New South Wales, Sydney, New South Wales 2052 (Australia)

2005-05-01

We present a study to determine the importance of phosphorus incorporation and hydrogen removal for the electrical activation of phosphorus dopants in Si:P {delta}-doped samples fabricated using phosphine dosing and molecular beam epitaxy (MBE). The carrier densities in these samples were determined from Hall effect measurements at 4 K sample temperature. An anneal to incorporate phosphorus atoms into substitutional lattice sites is critical to achieving full dopant activation after Si encapsulation by MBE. Whilst the presence of hydrogen can degrade the quality of the Si encapsulation layer, we show that it does not adversely impact the electrical activation of the phosphorus dopants. We discuss the relevance of our results to the fabrication of nano-scale Si:P devices. (copyright 2005 WILEY-VCH Verlag GmbH and C o. KGaA, Weinheim) (orig.)

76 FR 27649 - Disease, Disability, and Injury Prevention and Control Special Interest Projects (SIPs): Initial...

Science.gov (United States)

2011-05-12

... DEPARTMENT OF HEALTH AND HUMAN SERVICES Centers for Disease Control and Prevention Disease, Disability, and Injury Prevention and Control Special Interest Projects (SIPs): Initial Review The meeting... Committee Act (Pub. L. 92-463), the Centers for Disease Control and Prevention (CDC) announces the...

75 FR 30410 - Disease, Disability, and Injury Prevention and Control Special Interest Project (SIP): Provider...

Science.gov (United States)

2010-06-01

... DEPARTMENT OF HEALTH AND HUMAN SERVICES Centers for Disease Control and Prevention Disease, Disability, and Injury Prevention and Control Special Interest Project (SIP): Provider and Public Health... Federal Advisory Committee Act (Pub. L. 92-463), the Centers for Disease Control and Prevention (CDC...

Eficiência teórica de pilhas a combustível do tipo PaCOS

OpenAIRE

Amaral, Alexandre A.; Matos, Francisco F.; Benedicto, João Paulo; Boaventura, Jaime S.

2007-01-01

A célula a combustível do tipo óxido sólido (PaCOS) é um das mais promissoras tecnologias para a produção de energia elétrica, principalmente, devido ao fato de ser virtualmente não poluente. Tipicamente, a PaCOS é constituída de pelo menos sete fases distintas: combustível, ânodo, cátodo, eletrólito (separando os dois eletrodos), ar e interconectores elétricos (dois) para completar o circuito de corrente. É claramente demonstrado que os sistemas eletroquímicos só podem ser reversíveis quando...

78 FR 50360 - Approval and Promulgation of Air Quality Implementation Plans; Indiana; Infrastructure SIP...

Science.gov (United States)

2013-08-19

... ensure that the structural components of each state's air quality management program are adequate to meet... SIP. The Indiana Department of Environmental Management (IDEM) has requested that EPA approve these... ENVIRONMENTAL PROTECTION AGENCY 40 CFR Part 52 [EPA-R05-OAR-2011-0888; EPA-R05-OAR-2011-0969; EPA...

The strategy of the shelter implementation plan (SIP) performance

International Nuclear Information System (INIS)

Geras'ko, V.N.; Nosovskij, A.V.

1999-01-01

In 1997 the 'Shelter Implementation Plan' (SIP) was developed it's purpose was to transform Unit 4 of the Chernobyl NPP into the ecologically safe system. The Plan was developed by common efforts of the Ukrainian scientists, CES representatives and experts from the United States of America. The fact that there are no nuclear and radiation safety criteria for the projects will result into the situation when different designers might use within the various project tasks various design criteria. Till now o exact date for the constructions stabilization activities has been defined, and it creates a kind of on definiteness while developing the Radioactive Waste Management strategy and Safe Confinement

Elephant grass genotypes for bioenergy production by direct biomass combustion Genótipos de capim-elefante para produção de bioenergia por combustão direta da biomassa

Directory of Open Access Journals (Sweden)

Rafael Fiusa de Morais

2009-02-01

Full Text Available The objective of this work was to evaluate elephant grass (Pennisetum purpureum Schum. genotypes for bioenergy production by direct biomass combustion. Five elephant grass genotypes grown in two different soil types, both of low fertility, were evaluated. The experiment was carried out at Embrapa Agrobiologia field station in Seropédica, RJ, Brazil. The design was in randomized complete blocks, with split plots and four replicates. The genotypes studied were Cameroon, Bag 02, Gramafante, Roxo and CNPGL F06-3. Evaluations were made for biomass production, total biomass nitrogen, biomass nitrogen from biological fixation, carbon/nitrogen and stem/leaf ratios, and contents of fiber, lignin, cellulose and ash. The dry matter yields ranged from 45 to 67 Mg ha-1. Genotype Roxo had the lowest yield and genotypes Bag 02 and Cameroon had the highest ones. The biomass nitrogen accumulation varied from 240 to 343 kg ha-1. The plant nitrogen from biological fixation was 51% in average. The carbon/nitrogen and stem/leaf ratios and the contents of fiber, lignin, cellulose and ash did not vary among the genotypes. The five genotypes are suitable for energy production through combustion.O objetivo deste trabalho foi avaliar genótipos de capim-elefante (Pennisetum purpureum Schum. quanto ao potencial para a produção de bioenergia por combustão direta da biomassa. Avaliaram-se cinco genótipos de capim-elefante, em dois solos com baixa fertilidade. Os experimentos foram conduzidos na estação experimental da Embrapa Agrobiologia, em Seropédica, RJ. O delineamento experimental foi o de blocos ao acaso, em parcelas subdivididas, com quatro repetições. Os genótipos estudados foram Cameroon, Bag 02, Gramafante, Roxo e CNPGL F06-3. Determinaram-se a produção de biomassa, o acúmulo de nitrogênio na biomassa, o nitrogênio da biomassa proveniente da fixação biológica, as relações carbono/nitrogênio e talo/folha, e os teores de fibra, lignina

78 FR 45 - Approval and Promulgation of Implementation Plans; Georgia: New Source Review-Prevention of...

Science.gov (United States)

2013-01-02

... fermentation processes; CO 2 from combustion of the biological fraction of municipal solid waste or biosolids... approve portions of a revision to the Georgia State Implementation Plan (SIP) submitted by the State of... are not required by the Act as part of an approvable SIP program. EPA believes that most states are...

SiP monolayers: New 2D structures of group IV-V compounds for visible-light photohydrolytic catalysts

Science.gov (United States)

Ma, Zhinan; Zhuang, Jibin; Zhang, Xu; Zhou, Zhen

2018-06-01

Because of graphene and phosphorene, two-dimensional (2D) layered materials of group IV and group V elements arouse great interest. However, group IV-V monolayers have not received due attention. In this work, three types of SiP monolayers were computationally designed to explore their electronic structure and optical properties. Computations confirm the stability of these monolayers, which are all indirect-bandgap semiconductors with bandgaps in the range 1.38-2.21 eV. The bandgaps straddle the redox potentials of water at pH = 0, indicating the potential of the monolayers for use as watersplitting photocatalysts. The computed optical properties demonstrate that certain monolayers of SiP 2D materials are absorbers of visible light and would serve as good candidates for optoelectronic devices.

Stereotactic body radiotherapy (SBRT) in recurrent or oligometastatic pancreatic cancer. A toxicity review of simultaneous integrated protection (SIP) versus conventional SBRT

Energy Technology Data Exchange (ETDEWEB)

Gkika, E.; Kirste, S.; Schimek-Jasch, T. [University Medical Center Freiburg, Department of Radiation Oncology, Freiburg im Breisgau (Germany); Adebahr, S. [University Medical Center Freiburg, Department of Radiation Oncology, Freiburg im Breisgau (Germany); German Cancer Consortium (DKTK), Heidelberg (partner site Freiburg) (Germany); Wiehle, R. [University Medical Center Freiburg, Division of Medical Physics, Department of Radiation Oncology, Freiburg (Germany); Claus, R. [University Medical Center Freiburg, Department of Hematology, Oncology and Stem-Cell Transplantation, Freiburg (Germany); Wittel, U. [University Medical Center Freiburg, Department of General and Visceral Surgery, Freiburg (Germany); Nestle, U.; Grosu, A.L.; Brunner, T.B. [University Medical Center Freiburg, Department of Radiation Oncology, Freiburg im Breisgau (Germany); German Cancer Consortium (DKTK), Heidelberg (partner site Freiburg) (Germany); University of Freiburg, Faculty of Medicine, Freiburg (Germany); Baltas, D. [University Medical Center Freiburg, Division of Medical Physics, Department of Radiation Oncology, Freiburg (Germany); German Cancer Consortium (DKTK), Heidelberg (partner site Freiburg) (Germany); University of Freiburg, Faculty of Medicine, Freiburg (Germany)

2017-06-15

Stereotactic body radiotherapy (SBRT) in pancreatic cancer can be limited by its proximity to organs at risk (OAR). In this analysis, we evaluated the toxicity and efficacy of two different treatment approaches in patients with locally recurrent or oligometastatic pancreatic cancer. According to the prescription method, patients were divided in two cohorts (C1 and C2). The planning target volume (PTV) was created through a 4 mm expansion of the internal target volume. In C2, a subvolume was additionally created, a simultaneous integrated protection (SIP), which is the overlap of the PTV with the planning risk volume of an OAR to which we prescribed a reduced dose. In all, 18 patients were treated (7 with local recurrences, 9 for oligometastases, 2 for both). Twelve of 23 lesions were treated without SIP (C1) and 11 with SIP (C2). The median follow-up was 12.8 months. Median overall survival (OS) was 13.2 (95% confidence interval [CI] 9.8-14.6) months. The OS rates at 6 and 12 months were 87 and 58%, respectively. Freedom from local progression for combined cohorts at 6 and 12 months was 93 and 67% (95% CI 15-36), respectively. Local control was not statistically different between the two groups. One patient in C2 experienced grade ≥3 acute toxicities and 1 patient in C1 experienced a grade ≥3 late toxicity. The SIP approach is a useful prescription method for abdominal SBRT with a favorable toxicity profile which does not compromise local control and overall survival despite dose sacrifices in small subvolumes. (orig.) [German] Die stereotaktische Strahlentherapie (SBRT) ist bei Pankreaskarzinomen durch die enge Lagebeziehung der Risikoorgane (OAR) zum Zielvolumen erschwert. In dieser Analyse evaluierten wir die Toxizitaet und die Lokalkontrolle von zwei unterschiedlichen Therapiestrategien bei Patienten mit rezidivierendem oder oligometastatischem Pankreaskarzinom. Die Patienten wurden anhand der Verschreibungsmethode in zwei Kohorten geteilt (C1 und C2). Das

77 FR 30292 - Disease, Disability, and Injury Prevention and Control Special Interest Project (SIP): Initial...

Science.gov (United States)

2012-05-22

... DEPARTMENT OF HEALTH AND HUMAN SERVICES Centers for Disease Control and Prevention Disease, Disability, and Injury Prevention and Control Special Interest Project (SIP): Initial Review The meeting...)(2) of the Federal Advisory Committee Act (Pub. L. 92-463), the Centers for Disease Control and...

75 FR 30410 - Disease, Disability, and Injury Prevention and Control Special Interest Projects (SIPs): Outcomes...

Science.gov (United States)

2010-06-01

... DEPARTMENT OF HEALTH AND HUMAN SERVICES Centers for Disease Control and Prevention Disease, Disability, and Injury Prevention and Control Special Interest Projects (SIPs): Outcomes of Screening... 10(a)(2) of the Federal Advisory Committee Act (Pub. L. 92- 463), the Centers for Disease Control and...

Combustion

CERN Document Server

Glassman, Irvin

2008-01-01

Combustion Engineering, a topic generally taught at the upper undergraduate and graduate level in most mechanical engineering programs, and many chemical engineering programs, is the study of rapid energy and mass transfer usually through the common physical phenomena of flame oxidation. It covers the physics and chemistry of this process and the engineering applications-from the generation of power such as the internal combustion automobile engine to the gas turbine engine. Renewed concerns about energy efficiency and fuel costs, along with continued concerns over toxic and particulate emissions have kept the interest in this vital area of engineering high and brought about new developments in both fundamental knowledge of flame and combustion physics as well as new technologies for flame and fuel control. *New chapter on new combustion concepts and technologies, including discussion on nanotechnology as related to combustion, as well as microgravity combustion, microcombustion, and catalytic combustion-all ...

Multivariate statistical monitoring as applied to clean-in-place (CIP) and steam-in-place (SIP) operations in biopharmaceutical manufacturing.

Science.gov (United States)

Roy, Kevin; Undey, Cenk; Mistretta, Thomas; Naugle, Gregory; Sodhi, Manbir

2014-01-01

Multivariate statistical process monitoring (MSPM) is becoming increasingly utilized to further enhance process monitoring in the biopharmaceutical industry. MSPM can play a critical role when there are many measurements and these measurements are highly correlated, as is typical for many biopharmaceutical operations. Specifically, for processes such as cleaning-in-place (CIP) and steaming-in-place (SIP, also known as sterilization-in-place), control systems typically oversee the execution of the cycles, and verification of the outcome is based on offline assays. These offline assays add to delays and corrective actions may require additional setup times. Moreover, this conventional approach does not take interactive effects of process variables into account and cycle optimization opportunities as well as salient trends in the process may be missed. Therefore, more proactive and holistic online continued verification approaches are desirable. This article demonstrates the application of real-time MSPM to processes such as CIP and SIP with industrial examples. The proposed approach has significant potential for facilitating enhanced continuous verification, improved process understanding, abnormal situation detection, and predictive monitoring, as applied to CIP and SIP operations. © 2014 American Institute of Chemical Engineers.

Experimental Evaluation of a SIP-Based Home Gateway with Multiple Wireless Interfaces for Domotics Systems

Directory of Open Access Journals (Sweden)

Rosario G. Garroppo

2012-01-01

Full Text Available In modern houses, the presence of sensors and actuators is increasing, while communication services and entertainment systems had long since settled into everyday life. The utilization of wireless communication technologies, such as ZigBee, Wi-Fi, and Bluetooth, is attractive because of their short installation times and low costs. The research is moving towards the integration of the various home appliances and devices into a single domotics system, able to exploit the cooperation among the diverse subsystems and offer the end-user a single multiservice platform. In this scenario, the paper presents the experimental evaluation of a domotics framework centered on a SIP-based home gateway (SHG. While SIP is used to build a common control plane, the SHG is in charge of translating the user commands from and to the specific domotics languages. The analysis has been devoted to assess both the performance of the SHG software framework and the negative effects produced by the simultaneous interference among the three widespread wireless technologies.

Combustion

CERN Document Server

Glassman, Irvin

1997-01-01

This Third Edition of Glassman's classic text clearly defines the role of chemistry, physics, and fluid mechanics as applied to the complex topic of combustion. Glassman's insightful introductory text emphasizes underlying physical and chemical principles, and encompasses engine technology, fire safety, materials synthesis, detonation phenomena, hydrocarbon fuel oxidation mechanisms, and environmental considerations. Combustion has been rewritten to integrate the text, figures, and appendixes, detailing available combustion codes, making it not only an excellent introductory text but also an important reference source for professionals in the field. Key Features * Explains complex combustion phenomena with physical insight rather than extensive mathematics * Clarifies postulates in the text using extensive computational results in figures * Lists modern combustion programs indicating usage and availability * Relates combustion concepts to practical applications.

Design and construction of the SIPPING for fuels of the TRIGA Mark III reactor

International Nuclear Information System (INIS)

Castaneda J, G.; Delfin L, A.; Alvarado P, R.; Mazon R, R.; Ortega V, B.

2003-01-01

The sipping technique, it has been used by several possessors of nuclear research reactors in its irradiated nuclear fuels, likewise in some fuel storage sites, with the objective of to determine the quantity of radioactivity that the fuel liberates in the means in that it is. The irradiated fuel in storage of some nuclear research reactors, its can have cracks that cross the cladding of the same one, generating the liberation of fission products that its need to determine to maintain safety measures appropriate as much as the fuel as of the facilities where they are. It doesn't exist until now, some method published for the non destructive sipping test technique. Based on that described, the Reactor Department of the National Institute of Nuclear Research, it has designed and built an inspection system of irradiated fuel that it will allow the detection of gassy fission products in site, and solids by means of the measurement of the activity of the Cs-137 contained in water samples. (Author)

Caracterización de combustibles leñosos en el ejido Pueblo Nuevo, Durango

Directory of Open Access Journals (Sweden)

J. Bautista Rentería-Anima

2005-01-01

Full Text Available Se realizó un inventario de combustibles leñosos en una microcuenca del ejido Pueblo Nuevo, Dgo., para determinar las cargas de combustibles con peligro de propiciar incendios forestales. Se utilizó la técnica de intersecciones planares y en el análisis se consideró la anualidad, tratamientos silvícolas, productividad, pendiente y exposición. Los resultados muestran un incremento en la acumulación de combustible total a partir de la extracción, alcanzando su nivel máximo al tercer año. Las mayores concentraciones de combustibles se presentan en los tratamientos de cortas de regeneración y aclareos, en aquellas áreas con la mayor productividad, en pendiente moderada.

Desenvolvimento de métodos eletroanalíticos para determinação de compostos nitrogenados em combustíveis derivados do petróleo

OpenAIRE

Okumura, Leonardo Luiz [UNESP

2008-01-01

A presença de traços de compostos organonitrogenados (básicos e neutros), tais como, quinolina, piridina, carbazol e indol em combustíveis derivados do petróleo desempenham um importante papel no tempo de vida dos motores dos veículos. No entanto, essas substâncias podem contaminar o meio ambiente e por isso devem ser controladas, pois a maioria delas são potencialmente carcinogênicas e mutagênicas. Por estas razões, um método confiável e sensível foi desenvolvido para a determinação de compo...

Combustion engineering

CERN Document Server

Ragland, Kenneth W

2011-01-01

Introduction to Combustion Engineering The Nature of Combustion Combustion Emissions Global Climate Change Sustainability World Energy Production Structure of the Book   Section I: Basic Concepts Fuels Gaseous Fuels Liquid Fuels Solid Fuels Problems Thermodynamics of Combustion Review of First Law Concepts Properties of Mixtures Combustion StoichiometryChemical EnergyChemical EquilibriumAdiabatic Flame TemperatureChemical Kinetics of CombustionElementary ReactionsChain ReactionsGlobal ReactionsNitric Oxide KineticsReactions at a Solid SurfaceProblemsReferences  Section II: Combustion of Gaseous and Vaporized FuelsFlamesLaminar Premixed FlamesLaminar Flame TheoryTurbulent Premixed FlamesExplosion LimitsDiffusion FlamesGas-Fired Furnaces and BoilersEnergy Balance and EfficiencyFuel SubstitutionResidential Gas BurnersIndustrial Gas BurnersUtility Gas BurnersLow Swirl Gas BurnersPremixed-Charge Engine CombustionIntroduction to the Spark Ignition EngineEngine EfficiencyOne-Zone Model of Combustion in a Piston-...

Developments in the technology for the combustion of water emulsions in Mexican fuel oil; Desarrollos en la tecnologia para la combustion de emulsiones agua en combustoleo mexicano

Energy Technology Data Exchange (ETDEWEB)

Diego, Antonio Marin; Martinez Flores, Marco A.; Tamayo Flores, Gustavo; Alarcon Quiroz, Ernesto; Melendez Cervantes, Carlos [Instituto de Investigaciones Electricas, Temixco, Morelos (Mexico)

2001-07-01

The residual petroleum oil (fuel oil) is the most used fuel in boilers of electrical and industrial power stations. Nevertheless, the use of this fuel can generate diverse problems such as the elevated particle emissions, that affect the boiler efficiency, darken the visibility by the smoke that leaves the chimneys and is emitted to the Environment. In addition, sulfur trioxide is produced, which reacts with the water present in the combustion gases, forming sulfuric acid that, when emitted, also affects the visibility of the plume and can be condensed, originating corrosion and increased accumulation of deposits in the boilers. The experimental research was made in a comparative base, between combustion tests of fuel oil, with emulsions where the water concentration and the size of the drops of this one was varied. A diagram of the supply of fuel and preparation of emulsions in a pilot furnace is shown. The article contains graphs of the effect of the water concentration of the emulsions in the particulate emission. The article contains figures of the cenospheres produced by the fuel oil combustion (500 x) and the ones produced by the combustion with 5% of water (500 x). Also shows graphs of the effect of the water drop size of emulsions in the particulate emission, of the reduction of the sulfur trioxide with soluble magnesium products in the water of emulsions, and of the free particle acidity with neutralizers of water emulsions of soluble magnesium. [Spanish] El aceite residual de petroleo (combustoleo) es el combustible mas utilizado en calderas de centrales electricas e industriales. Sin embargo, el uso de este combustible puede generar diverso problemas como las emisiones elevadas de particulas, que afectan la eficiencia de una caldera, obscurecen la visibilidad pero el humo que sale de las chimeneas y se emiten al medio ambiente. Ademas se produce trioxido de azufre, el cual reacciona con el vapor de agua presente en los gases de combustion, formado acido

Analysis of Active Methylotrophic Communities: When DNA-SIP Meets High-Throughput Technologies.

Science.gov (United States)

Taubert, Martin; Grob, Carolina; Howat, Alexandra M; Burns, Oliver J; Chen, Yin; Neufeld, Josh D; Murrell, J Colin

2016-01-01

Methylotrophs are microorganisms ubiquitous in the environment that can metabolize one-carbon (C1) compounds as carbon and/or energy sources. The activity of these prokaryotes impacts biogeochemical cycles within their respective habitats and can determine whether these habitats act as sources or sinks of C1 compounds. Due to the high importance of C1 compounds, not only in biogeochemical cycles, but also for climatic processes, it is vital to understand the contributions of these microorganisms to carbon cycling in different environments. One of the most challenging questions when investigating methylotrophs, but also in environmental microbiology in general, is which species contribute to the environmental processes of interest, or "who does what, where and when?" Metabolic labeling with C1 compounds substituted with (13)C, a technique called stable isotope probing, is a key method to trace carbon fluxes within methylotrophic communities. The incorporation of (13)C into the biomass of active methylotrophs leads to an increase in the molecular mass of their biomolecules. For DNA-based stable isotope probing (DNA-SIP), labeled and unlabeled DNA is separated by isopycnic ultracentrifugation. The ability to specifically analyze DNA of active methylotrophs from a complex background community by high-throughput sequencing techniques, i.e. targeted metagenomics, is the hallmark strength of DNA-SIP for elucidating ecosystem functioning, and a protocol is detailed in this chapter.

Mezclas etanol-gasolina como combustible de motores de encendido por chispa

Directory of Open Access Journals (Sweden)

Rodríguez Luis Arnoby

1989-12-01

Full Text Available In the Agricultural Mechanics Shop at Texas A&I University in Kingsville (TX, six ethanolgasoline blends (0, 20, 40, 60, 80 and 100% ethanol were used to operated a six-cylinder engine at different operating conditions of air-fuel ratio, timing, load and speed. A main jet the carburator was used for each fuel to obtaining its stoichiometric air-fuel ratio. The main jet diameter was enlarged 1262 times from gasoline to ethanol. To select the optimun timing, timing was varied from Oto 26° BTOC (Before Top Oead Center and the engine tes1ed at maximun power. The optimun advance timings were respectively 6, 6, 10, 14, 18 and 220 BTOC. It was not necessary to introduce modifications to operate the engine with blends containing upto 20 % ethanol. For blends with more than 20% ethanol, the advance timing (V and the ethanol conmnt (X, followed the relation V = 2.0 + 02 X. In the last test, the engine was set at the optimun advance timing for each fuel. All the fuels performed in the same way. They followed the s e characteristic curves for power, torque, specific fuel consumption and efficiency with the following differences from gasoline to straight ethanol: maximun power and torque decreased 10.6% and 8.7% respectively; specific fuel consumption and efficiency increased 49% and 5.2%.
En el Taller de Mecánica Agrícola de Texas A&T University en Kingsville (TX, se usaron seis mezclas etanol-gasolina (0,20,40,60,80 y 100% etanol para operar un motor de seis cilindros variando la razón aire-combustible, avance de encendido, carga y velocidad. Con cada combustible se usó una tobera principal para obtener su razón estequiométrica. De gasolina a etanol el diámetro de la tobera se aumentó 1262 veces. El avance de la chispa se varió entre 0 y 26° APMS (Antes de Punto Muerto Superior. Se seleccionó como óptimo el avance al que el motor desarrolló máxima potencia. Los avances óptimos fueron 6, 6, 10, 14, 18 y 22° APMS. No fue necesario

Protective efficacy of cationic-PLGA microspheres loaded with DNA vaccine encoding the sip gene of Streptococcus agalactiae in tilapia.

Science.gov (United States)

Ma, Yan-Ping; Ke, Hao; Liang, Zhi-Ling; Ma, Jiang-Yao; Hao, Le; Liu, Zhen-Xing

2017-07-01

Streptococcus agalactiae (S. agalactiae) is an important fish pathogen, which has received more attention in the past decade due to the increasing economic losses in the tilapia industry worldwide. As existing effective vaccines of S. agalactiae in fish have obvious disadvantage, to select immunoprotective antigens and package materials would undoubtedly contribute to the development of novel oral vaccines. In the present study, surface immunogenic protein (sip) was selected from the S. agalactiae serovar I a genomes as immunogenic protein in DNA vaccine form with cationic chitosan and biodegradable and biocompatible PLGA. The pcSip plasmid in cationic-PLGA was successfully expressed in tissues of immunized tilapia and the immunogenicity was assessed in tilapia challenge model. A significant increase was observed in the cytokine levels of IL-1β, TNF-α, CC1, CC2 in spleen and kidney tissues. Furthermore, immunized tilapia conferred different levels of protection against challenge with a lethal dose of highly virulent serovar I a S. agalactiae. Our results indicated that the pcSip plasmid in cationic-PLGA induced high level of antibodies and protection against S. agalactiae infection, could be effective oral DNA vaccine candidates. Copyright © 2017 Elsevier Ltd. All rights reserved.

Impact of 50% Synthesized Iso-Paraffins (SIP) on Middle Distillate Fuel Filtration and Coalescence

Science.gov (United States)

2014-10-30

Paraffins DEFINITIONS Coalescence - the ability to shed water Conventional Material Source - crude oil , natural gas liquid condensates...Impact of 50% Synthesized Iso-Paraffins (SIP) on Middle Distillate Fuel Filtration and Coalescence NF&LCFT REPORT 441/15-003 30 October 2014...heavy oil , shale oil , and oil sands Effluent - stream leaving a system Influent - stream entering a system Turnover - time required to flow the

Combustion

CERN Document Server

Glassman, Irvin

1987-01-01

Combustion, Second Edition focuses on the underlying principles of combustion and covers topics ranging from chemical thermodynamics and flame temperatures to chemical kinetics, detonation, ignition, and oxidation characteristics of fuels. Diffusion flames, flame phenomena in premixed combustible gases, and combustion of nonvolatile fuels are also discussed. This book consists of nine chapters and begins by introducing the reader to heats of reaction and formation, free energy and the equilibrium constants, and flame temperature calculations. The next chapter explores the rates of reactio

Implementasi Server VoIP Berbasis SIP Pada LAN Nirkabel

Directory of Open Access Journals (Sweden)

Mohammad Shoffa Al Arofat

2013-03-01

Full Text Available Voice over Internet Protocol (VoIP merupakan teknologi yang memungkinkan percakapan suara jarak jauh melalui protokol internet. Dalam telekomunikasi, diperlukan teknologi pensinyalan yang berguna untuk membangun, mengawasi, dan melepas hubungan antara dua titik. Salah satu teknologi pensinyalan yang banyak digunakan untuk VoIP adalah Session Initiation Protocol, dengan implementasinya yang berupa perangkat lunak Open SIP Server. Selain pensinyalan, ada beberapa parameter yang perlu diperhatikan dalam implementasi VoIP, yaitu Mean Opinion Score (MOS, network impairment, dan bandwidth. Pengujian dilakukan terhadap enam codec, yaitu G.722, PCMA, PCMU, Speex, GSM, dan BV16. Berdasarkan hasil analisis dapat diambil kesimpulan bahwa codec yang menggunakan bandwidth paling rendah adalah Speex (27,12 kbps; Rata-rata delay yang dihasilkan oleh sipdroid lebih baik daripada jitsi.

RGC32 induces epithelial-mesenchymal transition by activating the Smad/Sip1 signaling pathway in CRC.

Science.gov (United States)

Wang, Xiao-Yan; Li, Sheng-Nan; Zhu, Hui-Fang; Hu, Zhi-Yan; Zhong, Yan; Gu, Chuan-Sha; Chen, Shi-You; Liu, Teng-Fei; Li, Zu-Guo

2017-05-04

Response gene to complement 32 (RGC32) is a transcription factor that regulates the expression of multiple genes involved in cell growth, viability and tissue-specific differentiation. However, the role of RGC32 in tumorigenesis and tumor progression in colorectal cancer (CRC) has not been fully elucidated. Here, we showed that the expression of RGC32 was significantly up-regulated in human CRC tissues versus adjacent normal tissues. RGC32 expression was significantly correlated with invasive and aggressive characteristics of tumor cells, as well as poor survival of CRC patients. We also demonstrated that RGC32 overexpression promoted proliferation, migration and tumorigenic growth of human CRC cells in vitro and in vivo. Functionally, RGC32 facilitated epithelial-mesenchymal transition (EMT) in CRC via the Smad/Sip1 signaling pathway, as shown by decreasing E-cadherin expression and increasing vimentin expression. In conclusion, our findings suggested that overexpression of RGC32 facilitates EMT of CRC cells by activating Smad/Sip1 signaling.

Pulsating combustion - Combustion characteristics and reduction of emissions

Energy Technology Data Exchange (ETDEWEB)

Lindholm, Annika

1999-11-01

In the search for high efficiency combustion systems pulsating combustion has been identified as one of the technologies that potentially can meet the objectives of clean combustion and good fuel economy. Pulsating combustion offers low emissions of pollutants, high heat transfer and efficient combustion. Although it is an old technology, the interest in pulsating combustion has been renewed in recent years, due to its unique features. Various applications of pulsating combustion can be found, mainly as drying and heating devices, of which the latter also have had commercial success. It is, however, in the design process of a pulse combustor, difficult to predict the operating frequency, the heat release etc., due to the lack of a well founded theory of the phenomenon. Research concerning control over the combustion process is essential for developing high efficiency pulse combustors with low emissions. Natural gas fired Helmholtz type pulse combustors have been the experimental objects of this study. In order to investigate the interaction between the fluid dynamics and the chemistry in pulse combustors, laser based measuring techniques as well as other conventional measuring techniques have been used. The experimental results shows the possibilities to control the combustion characteristics of pulsating combustion. It is shown that the time scales in the large vortices created at the inlet to the combustion chamber are very important for the operation of the pulse combustor. By increasing/decreasing the time scale for the large scale mixing the timing of the heat release is changed and the operating characteristics of the pulse combustor changes. Three different means for NO{sub x} reduction in Helmholtz type pulse combustors have been investigated. These include exhaust gas recirculation, alteration of air/fuel ratio and changed inlet geometry in the combustion chamber. All used methods achieved less than 10 ppm NO{sub x} emitted (referred to stoichiometric

Supersonic Combustion of Hydrogen Jets System in Hypersonic Stream

International Nuclear Information System (INIS)

Zhapbasbaev, U.K.; Makashev, E.P.

2003-01-01

The data of calculated theoretical investigations of diffusive combustion of plane supersonic hydrogen jets in hypersonic stream received with Navier-Stokes parabola equations closed by one-para metrical (k-l) model of turbulence and multiply staged mechanism of hydrogen oxidation are given. Combustion mechanisms depending on the operating parameters are discussing. The influences of air stream composition and ways off fuel feed to the length of ignition delay and level quantity of hydrogen bum-out have been defined. The calculated theoretical results of investigations permit to make the next conclusions: 1. The diffusive combustion of the system of plane supersonic hydrogen jets in hypersonic flow happens in the cellular structures with alternation zones of intensive running of chemical reactions with their inhibition zones. 2. Gas dynamic and heat Mach waves cause a large - scale viscous formation intensifying mixing of fuel with oxidizer. 3. The system ignition of plane supersonic hydrogen jets in hypersonic airy co-flow happens with the formation of normal flame front of hydrogen airy mixture with transition to the diffusive combustion. 4. The presence of active particles in the flow composition initiates the ignition of hydrogen - airy mixture, provides the intensive running of chemical reactions and shortens the length of ignition delay. 5. The supersonic combustion of hydrogel-airy mixture is characterized by two zones: the intensive chemical reactions with an active energy heat release is occurring in the first zone and in the second - a slow hydrogen combustion limited by the mixing of fuel with oxidizer. (author)

New technologies for the reduction of the use of fossil fuels in automobiles; Nuevas tecnologias para la reduccion del uso de combustibles fosiles en automoviles

Energy Technology Data Exchange (ETDEWEB)

Maya Violante, A.; Dorantes Rodriguez, R. [Universidad Autonoma Metropolitana, Unidad Azcapotzalco, Departamento de Energia, Mexico D. F. (Mexico)

1995-12-31

The new technologies developed for the reduction of the use of fossil fuels in automobiles can be classified by the way these try to reduce the use of energy. In the search for the technologies for the conservation of it the environmental problem is added, that although it is not the subject of this presentation results decisive for the evaluation of the performance of type of technology. The development of technologies in this field has followed three basic tendencies. First: The efficient improvement of internal combustion motors, which consist in the control and constant monitoring the functioning of these motors in order to determine the strictly necessary consumption for the motor operation in accordance with its load conditions. Second, the development of a system that utilizes alternate fuels, as is the case of hybrid vehicles, that utilize gas turbines that can burn these fuels. Third the development of electric driven and energy regeneration systems avoiding the use of fossil fuels. A fourth tendency could be considered, which consists in determining the best way of controlling and using the transportation time, with all the implicit benefits. The purpose of this paper is to answer all these questions beginning with a detailed revision of the main technological innovations developed by the leading car manufacturers at world level, such as BMW, Mercedes Benz, Ford, etc. concerned in bringing to the market the best vehicles that burn less or none fossil fuels and at the same time comply with the every day more strict standards on the environmental pollution subject. Through these innovations the advantages and disadvantages of each one of them are set forth, with special emphasis in the technologies that, to our concern, will be the most convenient to promote in the years to come. [Espanol] Las nuevas tecnologias desarrolladas para la reduccion del uso de combustibles fosiles en automoviles se pueden caracterizar por la manera en que estas tratan de reducir

New technologies for the reduction of the use of fossil fuels in automobiles; Nuevas tecnologias para la reduccion del uso de combustibles fosiles en automoviles

Energy Technology Data Exchange (ETDEWEB)

Maya Violante, A; Dorantes Rodriguez, R [Universidad Autonoma Metropolitana, Unidad Azcapotzalco, Departamento de Energia, Mexico D. F. (Mexico)

1996-12-31

The new technologies developed for the reduction of the use of fossil fuels in automobiles can be classified by the way these try to reduce the use of energy. In the search for the technologies for the conservation of it the environmental problem is added, that although it is not the subject of this presentation results decisive for the evaluation of the performance of type of technology. The development of technologies in this field has followed three basic tendencies. First: The efficient improvement of internal combustion motors, which consist in the control and constant monitoring the functioning of these motors in order to determine the strictly necessary consumption for the motor operation in accordance with its load conditions. Second, the development of a system that utilizes alternate fuels, as is the case of hybrid vehicles, that utilize gas turbines that can burn these fuels. Third the development of electric driven and energy regeneration systems avoiding the use of fossil fuels. A fourth tendency could be considered, which consists in determining the best way of controlling and using the transportation time, with all the implicit benefits. The purpose of this paper is to answer all these questions beginning with a detailed revision of the main technological innovations developed by the leading car manufacturers at world level, such as BMW, Mercedes Benz, Ford, etc. concerned in bringing to the market the best vehicles that burn less or none fossil fuels and at the same time comply with the every day more strict standards on the environmental pollution subject. Through these innovations the advantages and disadvantages of each one of them are set forth, with special emphasis in the technologies that, to our concern, will be the most convenient to promote in the years to come. [Espanol] Las nuevas tecnologias desarrolladas para la reduccion del uso de combustibles fosiles en automoviles se pueden caracterizar por la manera en que estas tratan de reducir

Combustible structural composites and methods of forming combustible structural composites

Science.gov (United States)

Daniels, Michael A.; Heaps, Ronald J.; Steffler, Eric D.; Swank, W. David

2013-04-02

Combustible structural composites and methods of forming same are disclosed. In an embodiment, a combustible structural composite includes combustible material comprising a fuel metal and a metal oxide. The fuel metal is present in the combustible material at a weight ratio from 1:9 to 1:1 of the fuel metal to the metal oxide. The fuel metal and the metal oxide are capable of exothermically reacting upon application of energy at or above a threshold value to support self-sustaining combustion of the combustible material within the combustible structural composite. Structural-reinforcing fibers are present in the composite at a weight ratio from 1:20 to 10:1 of the structural-reinforcing fibers to the combustible material. Other embodiments and aspects are disclosed.

Spectral induced polarization (SIP) measurement of NAPL contaminated soils

Science.gov (United States)

Schwartz, N.; Huisman, J. A.; Furman, A.

2010-12-01

The potential applicability of spectral induce polarization (SIP) as a tool to map NAPLs (non aqueous phase liquids) contaminants at the subsurface lead researchers to investigate the electric signature of those contaminant on the spectral response. However, and despite the cumulative efforts, the effect of NAPL on the electrical properties of soil, and the mechanisms that control this effect are largely unknown. In this work a novel experiment is designed to further examine the effect of NAPL on the electrical properties of partially saturated soil. The measurement system that used is the ZEL-SIP04 impedance meter developed at the Forschungszentrum Julich, Germany. The system accurately (nominal phase precision of 0.1 mrad below 1 kHz) measures the phase and the amplitude of a material possessing a very low polarization (such as soil). The sample holder has a dimension of 60 cm long and 4.6 cm in diameter. Current and potential electrodes were made of brass, and while the current electrodes were inserted in full into the soil, the contact between the potential electrode and the soil was made through an Agarose bridge. Two types of soils were used: clean quartz sand, and a mixture of sand with clean Bentonite. Each soil (sandy or clayey) was mixed with water to get saturation degree of 30%. Following the mixture with water, NAPL was added and the composite were mixed again. Packing was done by adding and compressing small portions of the soil to the column. A triplicate of each mixture was made with a good reproducible bulk density. Both for the sandy and clayey soils, the results indicate that additions of NAPL decrease the real part of the complex resistivity. Additionally, for the sandy soil this process is time depended, and that a further decrease in resistivity develops over time. The results are analyzed considering geometrical factors: while the NAPL is electrically insulator, addition of NAPL to the soil is expected to increase the connectivity of the

78 FR 41311 - Approval of Air Quality Implementation Plans; Indiana; Approval of “Infrastructure” SIP With...

Science.gov (United States)

2013-07-10

... copyrighted material, will be publicly-available only in hard copy. Publicly-available docket materials are available either electronically in www.regulations.gov or in hard copy at the U.S. Environmental Protection... SIP at 326 IAC 1-3-4(b)(8) that among other things, contained the Federally promulgated 2006 PM 2.5...

Calidad de los combustibles en Colombia

Directory of Open Access Journals (Sweden)

Jorge Humberto Arango

2009-05-01

Full Text Available Para conocer el estado actual de los combustibles usados en Colombia y para conocer las necesidades en el marco de los biocombustibles, el Ingeniero Jorge Humberto Arango, gerente de refinados de Ecopetrol, presenta un resumen de la calidad de la gasolina, diesel, biodiesel, y el gas natural, tomando en cuenta aspectos tales como el contenido de azufre, la presencia de aromáticos y la emisión de material particulado. En resumen, se muestra el interesante e importante trabajo de Ecopetrol desde los años 90, relacionado con el cumplimento de los estándares nacionales e internacionales. Por ejemplo, para el caso de diesel, Colombia muestra uno de los contenidos más bajos en azufre con respecto a Latinoamérica, llegando a niveles de 500 ppm para la ciudad de Bogotá. Para el caso de aromáticos en gasolina, Colombia presenta una de las mejores en el mundo en términos de aromáticos, con contenidos de gasolina regular en 20% y en gasolina Premium en 22 %. Por otro lado, la emisión de compuestos azufrados y material particulado no se está reduciendo en la misma proporción que la calidad de los combustibles colombianos, que están siendo mejorados especialmente en parque automotor de trasporte pesado antiguo (mayor de 25 años. / In order to acquire a brief understanding of the state o the fuels in Colombia and then frame the necessities for biofuels, the engineer Jorge Humberto Arango, fuels refining manager at Ecopetrol, displayed a summary regarding the work carried out by Ecopetrol during the last decade to improve the quality of gas, diesel, biodiesel, and natural gas by analyzing aspects such as sulfur and aromatics presence, and particle matter emissions when fueling motors. For example, sulfur concentration for Diesel reaches one of the lowest reported in Latinamerica (500 ppm moreover, the aromatics content in Colombian gasoline projects it as one of the best in world (regular gasoline, 20 % and Premium 22 %. On the other hand, even

Combustion Stratification for Naphtha from CI Combustion to PPC

KAUST Repository

Vallinayagam, R.

2017-03-28

This study demonstrates the combustion stratification from conventional compression ignition (CI) combustion to partially premixed combustion (PPC). Experiments are performed in an optical CI engine at a speed of 1200 rpm for diesel and naphtha (RON = 46). The motored pressure at TDC is maintained at 35 bar and fuelMEP is kept constant at 5.1 bar to account for the difference in fuel properties between naphtha and diesel. Single injection strategy is employed and the fuel is injected at a pressure of 800 bar. Photron FASTCAM SA4 that captures in-cylinder combustion at the rate of 10000 frames per second is employed. The captured high speed video is processed to study the combustion homogeneity based on an algorithm reported in previous studies. Starting from late fuel injection timings, combustion stratification is investigated by advancing the fuel injection timings. For late start of injection (SOI), a direct link between SOI and combustion phasing is noticed. At early SOI, combustion phasing depends on both intake air temperature and SOI. In order to match the combustion phasing (CA50) of diesel, the intake air temperature is increased to 90°C for naphtha. The combustion stratification from CI to PPC is also investigated for various level of dilution by displacing oxygen with nitrogen in the intake. The start of combustion (SOC) was delayed with the increase in dilution and to compensate for this, the intake air temperature is increased. The mixture homogeneity is enhanced for higher dilution due to longer ignition delay. The results show that high speed image is initially blue and then turned yellow, indicating soot formation and oxidation. The luminosity of combustion images decreases with early SOI and increased dilution. The images are processed to generate the level of stratification based on the image intensity. The level of stratification is same for diesel and naphtha at various SOI. When O concentration in the intake is decreased to 17.7% and 14

Vigilância sanitária em postos de revenda de combustíveis: aplicação de um modelo para integrar ações e promover a saúde do trabalhador

Directory of Open Access Journals (Sweden)

Isabela Giardini

Full Text Available Resumo Introdução: o benzeno, composto encontrado na gasolina, é reconhecido como agente cancerígeno e tem sido objeto de controle em âmbito mundial devido aos seus efeitos agudos e crônicos à saúde humana. No Brasil, trabalhadores de postos de revenda de combustíveis (PRC são expostos ao benzeno durante suas atividades ocupacionais. A Vigilância Sanitária, ao monitorar a exposição dos trabalhadores ao benzeno, pode avaliar os riscos e implementar estratégias para estabelecer um ambiente de trabalho mais seguro. Objetivo: suscitar a discussão sobre as ações da Vigilância Sanitária em postos de combustíveis baseada na aplicação do modelo Força-Motriz/Pressão/Situação/Exposição/Efeito/Ação (FPSEEA. Método: realização de uma ampla revisão da literatura com a finalidade de obter as informações necessárias para construção e desenvolvimento da matriz proposta no modelo. Discussão: foi possível identificar as deficiências existentes nos diferentes níveis institucionais que possuem suas ações voltadas à proteção da saúde do trabalhador e propor ações para avançar na reflexão sobre o modelo de desenvolvimento, modos de produção e exploração de recursos. Também foram identificadas as possíveis ações da Vigilância Sanitária a serem aplicadas no ambiente ocupacional de PRC para eliminação ou redução dos riscos à saúde aos quais os trabalhadores estão expostos.

Control predictivo económico de vehículos híbridos basados en pilas de combustible

OpenAIRE

Sampietro, Jose Luis; Costa Castelló, Ramon; Puig Cayuela, Vicenç

2015-01-01

Las pilas de combustible que utilizan el hidrógeno como combustible están siendo consideradas, en estos últimos años, como una alternativa a los combustibles fósiles para su uso en automóviles. Dicha tecnología se puede aplicar en los vehículos de propulsión híbrida. Este trabajo introduce el control predictivo económico (EMPC, siglas en inglés) como técnica de gestión óptima de la energía. Finalmente, se presentan simulaciones de varios escenarios, basados en un control EMPC, en donde se ...

IEA combustion agreement : a collaborative task on alternative fuels in combustion

International Nuclear Information System (INIS)

Larmi, M.

2009-01-01

The focus of the alternative fuels in combustion task of the International Energy Agency is on high efficiency engine combustion, furnace combustion, and combustion chemistry. The objectives of the task are to develop optimum combustion for dedicated fuels by fully utilizing the physical and chemical properties of synthetic and renewable fuels; a significant reduction in carbon dioxide, NOx and particulate matter emissions; determine the minimum emission levels for dedicated fuels; and meet future emission standards of engines without or with minimum after-treatment. This presentation discussed the alternative fuels task and addressed issues such as synthetic fuel properties and benefits. The anticipated future roadmap was presented along with a list of the synthetic and renewable engine fuels to be studied, such as neat oxygenates like alcohols and ethers, biogas/methane and gas combustion, fuel blends, dual fuel combustion, high cetane number diesel fuels like synthetic Fischer-Tropsch diesel fuel and hydrogenated vegetable oil, and low CN number fuels. Implementation examples were also discussed, such as fuel spray studies in optical spray bombs; combustion research in optical engines and combustion chambers; studies on reaction kinetics of combustion and emission formation; studies on fuel properties and ignition behaviour; combustion studies on research engines; combustion optimization; implementing the optimum combustion in research engines; and emission measurements. Overall milestone examples and the overall schedule of participating countries were also presented. figs.

Experimental study of 112 Gb/s short reach transmission employing PAM formats and SiP intensity modulator at 1.3 μm.

Science.gov (United States)

Chagnon, Mathieu; Osman, Mohamed; Poulin, Michel; Latrasse, Christine; Gagné, Jean-Frédéric; Painchaud, Yves; Paquet, Carl; Lessard, Stéphane; Plant, David

2014-08-25

We present a Silicon Photonic (SiP) intensity modulator operating at 1.3 μm with pulse amplitude modulation formats for short reach transmission employing a digital to analog converter for the RF signal generator, enabling pulse shaping and precompensation of the transmitter's frequency response. Details of the SiP Mach-Zehnder interfometer are presented. We study the system performance at various bit rates, PAM orders and propagation distances. To the best of our knowledge, we report the first demonstration of a 112 Gb/s transmission over 10 km of SMF fiber operating below pre-FEC BER threshold of 3.8 × 10(-3) employing PAM-8 at 37.4 Gbaud using a fully packaged SiP modulator. An analytical model for the Q-factor metric applicable for multilevel PAM-N signaling is derived and accurately experimentally verified in the case of Gaussian noise limited detection. System performance is experimentally investigated and it is demonstrated that PAM order selection can be optimally chosen as a function of the desired throughput. We demonstrate the ability of the proposed transmitter to exhibit software-defined transmission for short reach applications by selecting PAM order, symbol rate and pulse shape.

Plasma cleaning and analysis of archeological artefacts from Sipán

Science.gov (United States)

Saettone, E. A. O.; da Matta, J. A. S.; Alva, W.; Chubaci, J. F. O.; Fantini, M. C. A.; Galvão, R. M. O.; Kiyohara, P.; Tabacniks, M. H.

2003-04-01

A novel procedure using plasma sputtering in an electron-cyclotron-resonance device has been applied to clean archeological MOCHE artefacts, unearthed at the Royal Tombs of Sipán. After successful cleaning, the pieces were analysed by a variety of complementary techniques, namely proton-induced x-ray emission, Rutherford backscattering spectroscopy, x-ray diffraction, electron microscopy, and inductively coupled plasma mass spectroscopy. With these techniques, it has been possible to not only determine the profiles of the gold and silver surface layers, but also to detect elements that may be relevant to explain the gilding techniques skillfully developed by the metal smiths of the MOCHE culture.

Internal combustion engine using premixed combustion of stratified charges

Science.gov (United States)

Marriott, Craig D [Rochester Hills, MI; Reitz, Rolf D [Madison, WI

2003-12-30

During a combustion cycle, a first stoichiometrically lean fuel charge is injected well prior to top dead center, preferably during the intake stroke. This first fuel charge is substantially mixed with the combustion chamber air during subsequent motion of the piston towards top dead center. A subsequent fuel charge is then injected prior to top dead center to create a stratified, locally richer mixture (but still leaner than stoichiometric) within the combustion chamber. The locally rich region within the combustion chamber has sufficient fuel density to autoignite, and its self-ignition serves to activate ignition for the lean mixture existing within the remainder of the combustion chamber. Because the mixture within the combustion chamber is overall premixed and relatively lean, NO.sub.x and soot production are significantly diminished.

Combustion Stratification for Naphtha from CI Combustion to PPC

KAUST Repository

Vallinayagam, R.; Vedharaj, S.; An, Yanzhao; Dawood, Alaaeldin; Izadi Najafabadi, Mohammad; Somers, Bart; Johansson, Bengt

2017-01-01

This study demonstrates the combustion stratification from conventional compression ignition (CI) combustion to partially premixed combustion (PPC). Experiments are performed in an optical CI engine at a speed of 1200 rpm for diesel and naphtha (RON

Fuel and combustion stratification study of Partially Premixed Combustion

OpenAIRE

Izadi Najafabadi, M.; Dam, N.; Somers, B.; Johansson, B.

2016-01-01

Relatively high levels of stratification is one of the main advantages of Partially Premixed Combustion (PPC) over the Homogeneous Charge Compression Ignition (HCCI) concept. Fuel stratification smoothens heat release and improves controllability of this kind of combustion. However, the lack of a clear definition of “fuel and combustion stratifications” is obvious in literature. Hence, it is difficult to compare stratification levels of different PPC strategies or other combustion concepts. T...

Sistemas redox reversíveis Fe°/óxido de ferro para produção de hidrogênio

OpenAIRE

Marcelo Goncalves Rosmaninho

2010-01-01

O hidrogênio é o combustível do futuro, seja pela eficiência energética ou pelo aspecto ambiental. Os maiores desafios nesta área hoje são encontrar formas eficientes de produzir hidrogênio para estas aplicações e encontrar formas seguras, simples e de baixo custo para seu armazenamento. Neste trabalho de doutorado foi investigado um sistema inovador para a produção de hidrogênio utilizando combustíveis renováveis e/ou baixo custo e de baixo impacto ambiental tais como etanol, gás natural e l...

Obtención de combustibles a partir de residuos plásticos

OpenAIRE

Proaño, Oswaldo; Crespo, Sara

2009-01-01

Para la obtención de hidrocarburos que puedan utilizarse como combustibles, se realizó la pirolisis del polietileno de alta densidad, empleado en el cultivo de banano, para cubrir el racimo de los frutos. Empleando un reactor de laboratorio de 1 dm3 de capacidad, se experimentó a temperaturas de 300, 350 y 400 ?C y tiempos de 0,5, 1 y 2 horas. A temperaturas menores a 300 ?C solamente se obtiene un producto sólido resinoso La mayor cantidad de productos líquidos se obtiene a 400 ?...

Extended Password Recovery Attacks against APOP, SIP, and Digest Authentication

Science.gov (United States)

Sasaki, Yu; Wang, Lei; Ohta, Kazuo; Kunihiro, Noboru

In this paper, we propose password recovery attacks against challenge-response authentication protocols. Our attacks use a message difference for a MD5 collision attack proposed in IEICE 2008. First, we show how to efficiently find a message pair that collides with the above message difference. Second, we show that a password used in authenticated post office protocol (APOP) can be recovered practically. We also show that the password recovery attack can be applied to a session initiation protocol (SIP) and digest authentication. Our attack can recover up to the first 31 password characters in a short time and up to the first 60 characters faster than the naive search method. We have implemented our attack and confirmed that 31 characters can be successfully recovered.

Viabilidade econômica e mecânica para conversão de motor de combustão interna, a sistemas de combustível flex

OpenAIRE

Mosquera Artamonov, José Daniel; Ortiz Gil, Christian David; Fernández Henao, Sergio Augusto; Mosquera Mosquera, Julio César

2011-01-01

Introduction. This paper introduces the results of a research work made in Pereira and Dosquebradas, in the Risaralda province, about the economic and mechanic feasibility of the conversion of internal combustion engines to flex fuel systems. For the study, a sample of taxi drivers was chosen in the region, given the high consumption of fossil fuel they require for every day of work. Objective. To determine the economic and mechanic feasibility of converting the internal combustion engines ta...

Dynamic behavior of correlated electrons in the insulating doped semiconductor Si:P

Energy Technology Data Exchange (ETDEWEB)

Ritz, Elvira

2009-06-04

At low energy scales charge transport in the insulating Si:P is dominated by activated hopping between the localized donor electron states. Theoretical models for a disordered electronic system with a long-range Coulomb interaction are appropriate to interpret the electric conductivity spectra. With a novel and advanced method we perform broadband phase sensitive measurements of the reflection coefficient from 45 MHz up to 5 GHz, employing a vector network analyzer with a 2.4 mm coaxial sensor, which is terminated by the sample under test. While the material parameters (conductivity and permittivity) can be easily extracted from the obtained impedance data if the sample is metallic, no direct solution is possible if the material under investigation is an insulator. Focusing on doped semiconductors with largely varying conductivity and dielectric function, we present a closed calibration and evaluation procedure with an optimized theoretical and experimental complexity, based on the rigorous solution for the electromagnetic field inside the insulating sample, combined with the variational principle. Basically no limiting assumptions are necessary in a strictly defined parameter range. As an application of our new method, we have measured the complex broadband microwave conductivity of Si:P in a broad range of phosphorus concentration n/n{sub c} from 0.56 to 0.9 relative to the critical value n{sub c}=3.5 x 10{sup 18} cm{sup -3} of the metal-insulator transition driven by doping at temperatures down to 1.1 K, and studied unresolved issues of fundamental research concerning the electronic correlations and the metal-insulator transition. (orig.)

Caso de estudio. Tablas de salvación para la industria azucarera colombiana. Caso del Trimestre

OpenAIRE

Benavides Franco, Julián

2003-01-01

Las perspectivas para el etanol combustible nunca han sido tan halagüeñas. Es probable que el renovado entusiasmo por los biocombustibles desate una gigantesca demanda global de etanol combustible. Esto es lo que afirman los que esperan que la legislación propuesta en los Estados Unidos y la Unión Europea, que obliga a la inclusión de biocombustibles en los carburantes para el transporte, sea adoptada pronto. Además de estas dos "grandes" iniciativas sobre biocombustibles, están los incipient...

Measures for a quality combustion (combustion chamber exit and downstream); Mesures pour une combustion de qualite (sortie de chambre de combustion et en aval)

Energy Technology Data Exchange (ETDEWEB)

Epinat, G. [APAVE Lyonnaise, 69 (France)

1996-12-31

After a review of the different pollutants related to the various types of stationary and mobile combustion processes (stoichiometric, reducing and oxidizing combustion), measures and analyses than may be used to ensure the quality and efficiency of combustion processes are reviewed: opacimeters, UV analyzers, etc. The regulation and control equipment for combustion systems are then listed, according to the generator capacity level

Hydraulic modelling of the CARA Fuel element; Desarrollo hidraulico del combustible CARA

Energy Technology Data Exchange (ETDEWEB)

Brasnarof, Daniel O; Juanico, Luis [Comision Nacional de Energia Atomica, San Carlos de Bariloche (Argentina). Disenios Avanzados y Evaluacion Economica; Giorgi, M [Comision Nacional de Energia Atomica, General San Martin (Argentina). Dept. de Materiales; Ghiselli, Alberto M; Zampach, Ruben; Fiori, Jose M; Yedros, Pablo A [Comision Nacional de Energia Atomica, General San Martin (Argentina). Dept. de Ensayos no Destructivos

2004-07-01

The CARA fuel element is been developing by the National Atomic Energy Commission for both Argentinean PHWRs. In order to keep the hydraulic restriction in their fuel channels, one of CARA's goals is to keep its similarity with both present fuel elements. In this paper is presented pressure drop test performed at a low-pressure facility (Reynolds numbers between 5x10{sup 4} and 1,5x10{sup 5}) and rational base models for their spacer grid and rod assembly. Using these models, we could estimate the CARA hydraulic performance in reactor conditions that have shown to be satisfactory. (author) [Spanish] Con el objeto de validar la similitud hidraulica del elemento combustible CARA con los actuales combustibles de Atucha y Embalse, se realizaron ensayos de perdida de carga en el circuito CBP del CAC con un nuevo diseno de separador de mejor desempeno hidraulico. Se presenta aqui el analisis de los mismos, de los cuales se validaron modelos de base racional para estimar las restricciones hidraulicas de los distintos componentes estructurales (separadores, grillas y barras combustibles) en funcion del flujo refrigerante. Se estimo asi la caida de presion del CARA dentro del canal combustible Embalse en condiciones nominales de reactor, siendo la misma similar al del combustible actual de 37 barras. (autor)

Combustion stratification for naphtha from CI combustion to PPC

NARCIS (Netherlands)

Vallinayagam, R.; Vedharaj, S.; An, Y.; Dawood, A.; Izadi Najafabadi, M.; Somers, L.M.T.; Johansson, B.H.

2017-01-01

This study demonstrated the change in combustion homogeneity from conventional diesel combustion via partially premixed combustion towards HCCI. Experiments are performed in an optical diesel engine at a speed of 1200 rpm with diesel fuel. Single injection strategy is employed and the fuel is

Low NOx combustion technologies for high-temperature natural gas combustion

International Nuclear Information System (INIS)

Flamme, Michael

1999-01-01

Because of the high process temperature which is required for some processes like glass melting and the high temperature to which the combustion air is preheated, NOx emission are extremely high. Even at these high temperatures, NOx emissions could be reduced drastically by using advanced combustion techniques such as staged combustion or flame-less oxidation, as experimental work has shown. In the case of oxy-fuel combustion, the NOx emission are also very high if conventional burners are used. The new combustion techniques achieve similar NOx reductions. (author)

Evaluación de la eficiencia de remoción de material particulado y dióxido de azufre (so2) en un lavador tipo venturi para una caldera que emplea carbón como combustible

OpenAIRE

Jiménez Riaño, Quelver Yesid

2012-01-01

El aporte de las emisiones industriales a la contaminación del aire de Bogotá es significativo y, dentro de las industrias, aquellas que usan carbón como fuente de combustible para la generación de vapor en calderas son las que mayor impacto negativo tiene en la calidad del aire de la ciudad. En este trabajo se llevó a cabo la evaluación de las variables de operación de un sistema de control de emisiones atmosféricas para una caldera industrial a carbón. Se diseño, construyó y puso en marcha ...

Proposta para o escoamento do coque verde de petróleo da Refinaria de Pernambuco: uma abordagem logística

OpenAIRE

Silveira Lapa, Arthur

2010-01-01

Entre os esforços que o Ministério do Meio Ambiente tem feito para melhoria da qualidade do ar no Brasil, está o Programa de Controle de Emissões Veiculares (PROCONVE). Ele estabelece metas que afetam diretamente a qualidade dos combustíveis utilizados para que haja limites máximos para as emissões de poluentes. Visando atender aos novos padrões de exigência, a Petróleo Brasileiro S.A. (Petrobras), principal responsável pelo suprimento de combustíveis do país, vem adequando a especificação de...

Desarrollo y validación experimental de un modelo computacional de pilas de combustible tipo PEM y su aplicación al análisis de monoceldas

OpenAIRE

Iranzo Paricio, Alfredo

2010-01-01

La presente tesis doctoral tiene como objetivo fundamental el desarrollo de un modelo computacional para pilas de combustible tipo PEM, que suponga un avance con respecto al estado actual del modelado de pilas de combustible. ... * Desarrollo de un model

Combustion instability control in the model of combustion chamber

International Nuclear Information System (INIS)

Akhmadullin, A N; Ahmethanov, E N; Iovleva, O V; Mitrofanov, G A

2013-01-01

An experimental study of the influence of external periodic perturbations on the instability of the combustion chamber in a pulsating combustion. As an external periodic disturbances were used sound waves emitted by the electrodynamics. The purpose of the study was to determine the possibility of using the method of external periodic perturbation to control the combustion instability. The study was conducted on a specially created model of the combustion chamber with a swirl burner in the frequency range from 100 to 1400 Hz. The study found that the method of external periodic perturbations may be used to control combustion instability. Depending on the frequency of the external periodic perturbation is observed as an increase and decrease in the amplitude of the oscillations in the combustion chamber. These effects are due to the mechanisms of synchronous and asynchronous action. External periodic disturbance generated in the path feeding the gaseous fuel, showing the high efficiency of the method of management in terms of energy costs. Power required to initiate periodic disturbances (50 W) is significantly smaller than the thermal capacity of the combustion chamber (100 kW)

Carbones pobres. Utilización de combustibles pobres en la fabricación de cemento

Directory of Open Access Journals (Sweden)

Guillon, M. Henri

1958-12-01

Full Text Available Not availableEn el trabajo que vamos a exponer a continuación, se considerará el empleo de los combustibles pobres desde el punto de visto térmico. De este modo, por una parte se examinará el papel que desempeñan como agentes de calefacción y no como aportadores de elementos minerales a la materia prima; por otra parte, se tratará de aquellos combustibles pobres para los cuales la materia combustible es el elemento más importante en oposición a algunas materias de recuperación, desechos de minas o cenizas de hogares, por ejemplo, que contienen principalmente materias minerales y accesoriamente alguna proporción de carbono.

Emulsified fuels. Its use in stationary sources; Combustibles emulsionados. Su utilizacion en fuentes estacionarias

Energy Technology Data Exchange (ETDEWEB)

Campos Morales, Gilberto; Magdaleno Molina, Moises; Vargas Y, Victor M; Gavira D, A [Instituto Mexicano del Petroleo, Mexico, D. F. (Mexico)

1993-12-31

Basic aspects are set forth of the heavy hydrocarbon fuels, the principles, preparation and particularities of the combustion with emulsions, that currently represent one option, either by themselves or in combination with other technologies to utilize heavy hydrocarbons, obtaining advantages in the reduction of polluting emissions, particulate matter and NOx, which allow continuing operating the operation within the limits established by the technical ecological standards. [Espanol] Se exponen aspectos basicos de los combustibles de hidrocarburos pesados (HC), los principios, preparacion y particularidades de la combustion con emulsiones, que actualmente representan una alternativa por si solos o en combinacion con otras tecnologias para utilizar hidrocarburos pesados, obteniendose ventajas en la reduccion de emisiones de contaminantes de particulas y NOx, lo cual permite continuar operando dentro de los limites que establecen las normas tecnicas ecologicas.

Emulsified fuels. Its use in stationary sources; Combustibles emulsionados. Su utilizacion en fuentes estacionarias

Energy Technology Data Exchange (ETDEWEB)

Campos Morales, Gilberto; Magdaleno Molina, Moises; Vargas Y, Victor M.; Gavira D, A. [Instituto Mexicano del Petroleo, Mexico, D. F. (Mexico)

1992-12-31

Basic aspects are set forth of the heavy hydrocarbon fuels, the principles, preparation and particularities of the combustion with emulsions, that currently represent one option, either by themselves or in combination with other technologies to utilize heavy hydrocarbons, obtaining advantages in the reduction of polluting emissions, particulate matter and NOx, which allow continuing operating the operation within the limits established by the technical ecological standards. [Espanol] Se exponen aspectos basicos de los combustibles de hidrocarburos pesados (HC), los principios, preparacion y particularidades de la combustion con emulsiones, que actualmente representan una alternativa por si solos o en combinacion con otras tecnologias para utilizar hidrocarburos pesados, obteniendose ventajas en la reduccion de emisiones de contaminantes de particulas y NOx, lo cual permite continuar operando dentro de los limites que establecen las normas tecnicas ecologicas.

Estudio de modificaciones geométricas en boquillas de calderas piro y acuotubulares para la combustión eficiente de crudos pesados // Study of geometric modifications in pyro and aquatubular mouthpieces of boilers for the efficient combustion of heavy oil

Directory of Open Access Journals (Sweden)

E. Lincheta Mesa

2000-07-01

Full Text Available Se presenta un estudio de boquillas de quemadores de calderas piro y acuotubulares. Se analizan diferentes variantes en lasdimensiones, forma y posición de los conductos de atomizador que dan paso al combustible y al fluido auxiliar en el casode quemadores con atomización por vapor.En todos los casos se evalúa el cono de pulverización y la calidad del spray, analizando la influencia de la presión deatomización y de la configuración geométrica en la eficiencia de atomización.Se determina la eficiencia de la combustión con varios tipos de boquillas, demostrándose la efectividad de lasmodificaciones introducidas cuando se queman combustibles de menor calidad.Se concluye que es posible sustituir algunas boquillas de importación y elevar la eficiencia en la combustión de crudospesados y sus mezclas, con un significativo efecto económico y como un paso más en el perfeccionamiento de las CentralesEléctricas del país para el aprovechamiento del crudo nacional.Palabras claves: quemador, atomizador, fuel oil, caldera, generación de vapor, combustibles, combustión._____________________________________________________________________Abstract :It is presented a study of mouthpieces of pyro and aquatubular burners of boilers. Different variants are analyzed indimensions, forms and position of the atomizer conduits that open the way to the fuel and auxiliary fluid in case of burnerswith steam atomization.In all cases, it is evaluated the pulverization cone and the quality of spray, analyzing the influence of atomization pressureand geometric configuration in the atomization efficiency.Estudio de modificaciones geométricas en boquillas de calderas piro y acuotubulares para la combustión eficiente decrudos pesadosThe efficiency of combustion is determined with several types of mouthpieces. The effectiveness of the introducedmodifications in connection with the import mouthpieces is demonstrated when fuels of smaller quality burns.It is

Rotary combustion device

NARCIS (Netherlands)

2008-01-01

Rotary combustion device (1) with rotary combustion chamber (4). Specific measures are taken to provide ignition of a combustible mixture. It is proposed that a hollow tube be provided coaxially with the axis of rotation (6), so that a small part of the mixture is guided into the combustion chamber.

Combustion physics

Science.gov (United States)

Jones, A. R.

1985-11-01

Over 90% of our energy comes from combustion. By the year 2000 the figure will still be 80%, even allowing for nuclear and alternative energy sources. There are many familiar examples of combustion use, both domestic and industrial. These range from the Bunsen burner to large flares, from small combustion chambers, such as those in car engines, to industrial furnaces for steel manufacture or the generation of megawatts of electricity. There are also fires and explosions. The bountiful energy release from combustion, however, brings its problems, prominent among which are diminishing fuel resources and pollution. Combustion science is directed towards finding ways of improving efficiency and reducing pollution. One may ask, since combustion is a chemical reaction, why physics is involved: the answer is in three parts. First, chemicals cannot react unless they come together. In most flames the fuel and air are initially separate. The chemical reaction in the gas phase is very fast compared with the rate of mixing. Thus, once the fuel and air are mixed the reaction can be considered to occur instantaneously and fluid mechanics limits the rate of burning. Secondly, thermodynamics and heat transfer determine the thermal properties of the combustion products. Heat transfer also plays a role by preheating the reactants and is essential to extracting useful work. Fluid mechanics is relevant if work is to be performed directly, as in a turbine. Finally, physical methods, including electric probes, acoustics, optics, spectroscopy and pyrometry, are used to examine flames. The article is concerned mainly with how physics is used to improve the efficiency of combustion.

Fuel oil combustion with low production of nitrogen oxides; Combustion de combustoleo con baja produccion de oxidos de nitrogeno

Energy Technology Data Exchange (ETDEWEB)

Escalera Campoverde, Rogelio [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

1998-09-01

This work presents the results of the theoretical-experimental study of the effects of the secondary air jet directed perpendicularly to the flame axis in the fuel oil combustion in a 500 Kw furnace. The main purpose of this study was to obtain low nitrogen oxides (NO{sub x}) emissions without increasing the CO, which is observed in low NO{sub x} conventional burners. The experimental results showed a significative reduction of the NO{sub x} and of the CO, from 320 to 90 ppm and from 50 ppm to negligible values, respectively. A commercial computational code of fluid dynamics was employed for modeling the combustion in base line conditions, without secondary air and with the injection of secondary air. The experimental results were compared with calculated ones. [Espanol] En este trabajo se presentan los resultados del estudio teorico experimental de los efectos de los chorro de aire secundario dirigidos en forma perpendicular al eje de la flama en la combustion del combustoleo en un horno de 500 kW. El proposito principal del estudio fue obtener bajas emisiones de oxidos de nitrogeno (NO{sub x}) sin incrementar el CO, lo cual se observa en quemadores convencionales de bajo NO{sub x}. Los resultados experimentales demostraron una reduccion significativa del NO{sub x} y del CO: de 320 a 90 ppm y de 50 ppm a valores despreciables, respectivamente. Se empleo un codigo computacional comercial de dinamica de fluidos para modelar la combustion en condiciones de linea base, sin aire secundario, y con la inyeccion del aire secundario. Se comparan resultados experimentales con los calculados.

Psychosocial work factors and first depressive episode: retrospective results from the French national SIP survey

OpenAIRE

Niedhammer , Isabelle; Chastang , Jean-François

2015-01-01

International audience; Objectives : The objective was to explore the associations between psychosocial work factors and first depressive episode. Additional objectives included the study of the frequency and duration of exposure, and the evaluation of the induction period between exposures and outcome and of the reversibility of the effects.Methods : The study was based on a sample of 13,648 men and women from the 2006 national representative French SIP survey. Retrospective evaluation was p...

Modelagem, controle e otimização de consumo de combustível para um veículo híbrido elétrico série-paralelo.

OpenAIRE

Ivan Miguel Trindade

2016-01-01

O principal objetivo dos veículos híbridos é diminuir o consumo de combustível em relação a veículos convencionais. Para isso, existe a necessidade de realizar a integração dos diferentes sistemas do trem-de-força e coordenar o seu funcionamento através de estratégias de controle. Tais estratégias são desenvolvidas e simuladas em conjunto com um modelo computacional da planta do veículo antes de serem aplicadas em uma unidade de controle eletrônica. O presente estudo tem como objetivo analisa...

Some Factors Affecting Combustion in an Internal-Combustion Engine

Science.gov (United States)

Rothrock, A M; Cohn, Mildred

1936-01-01

An investigation of the combustion of gasoline, safety, and diesel fuels was made in the NACA combustion apparatus under conditions of temperature that permitted ignition by spark with direct fuel injection, in spite of the compression ratio of 12.7 employed. The influence of such variables as injection advance angle, jacket temperature, engine speed, and spark position was studied. The most pronounced effect was that an increase in the injection advance angle (beyond a certain minimum value) caused a decrease in the extent and rate of combustion. In almost all cases combustion improved with increased temperature. The results show that at low air temperatures the rates of combustion vary with the volatility of the fuel, but that at high temperatures this relationship does not exist and the rates depend to a greater extent on the chemical nature of the fuel.

Reduced NOX combustion method

International Nuclear Information System (INIS)

Delano, M.A.

1991-01-01

This patent describes a method for combusting fuel and oxidant to achieve reduced formation of nitrogen oxides. It comprises: It comprises: heating a combustion zone to a temperature at least equal to 1500 degrees F.; injecting into the heated combustion zone a stream of oxidant at a velocity within the range of from 200 to 1070 feet per second; injecting into the combustion zone, spaced from the oxidant stream, a fuel stream at a velocity such that the ratio of oxidant stream velocity to fuel stream velocity does not exceed 20; aspirating combustion gases into the oxidant stream and thereafter intermixing the aspirated oxidant stream and fuel stream to form a combustible mixture; combusting the combustible mixture to produce combustion gases for the aspiration; and maintaining the fuel stream substantially free from contact with oxidant prior to the intermixture with aspirated oxidant

Cálculo de un sistema de inyección multifuel para motores Diesel

OpenAIRE

PAVÍA PARRA, MARC

2015-01-01

[ES] Los nuevos diseños de motores buscan como estrategia la combinación de propiedades de los combustibles Diesel y gasolina convencionales, por sus ventajas en cuanto a rendimiento y emisiones. El presente proyecto calculará el impacto que estos cambios pueden tener sobre la mezcla combustible-aire, y cómo se quema el combustible en el motor. Para ello se empleará un código de cálculo 1D de chorros, en el cual se definen las condiciones de contorno en el cilindro del motor y se puede predec...

Ecology versus economy: is biohydrogen the fuel of the future?; Ecologia contra Economia: ¿es el biohidrogeno el combustible del futuro?

Energy Technology Data Exchange (ETDEWEB)

Patino, Rodrigo [Centro de Investigacion y de Estudios Avanzados, Unidad Merida, Merida, Yucatan (Mexico)] e-mail: rtarkus@mda.cinvestav.mx

2009-09-15

This work presents a literature review of scientific research on different methodologies developed to produce hydrogen. Current processes to obtain commercial hydrogen are completely unsustainable in terms of the use of natural resources and environmental degradation. Different bioprocesses have been proposed in recent years as environmentally clean alternatives to produce combustible gases, but balance has not yet been obtained between production costs and performance. Therefore, a comparative analysis is performed of the different methods to obtain hydrogen, their limitations and the future prospects for each one. An in-depth reflection is also provided about challenges and recommendations for scientific and technological research aimed at proposing hydrogen (or biohydrogen) as the substitute for fossil fuels over the course of the 21st century, including not only its production but also storage and energy transformation mechanisms. [Spanish] En este trabajo se presenta una revision bibliografica acerca de las distintas metodologias desarrolladas en investigacion cientifica para producir hidrogeno. Los procesos actuales por los que se obtiene hidrogeno comercial son completamente insostenibles en cuanto a la utilizacion de recursos naturales y deterioro del medio ambiente. En los ultimos anos se han propuesto distintos bioprocesos como alternativas medioambientalmente limpias para la produccion del combustible gaseoso, pero aun no se llega a obtener un balance entre los costos y los rendimientos de produccion. Se hace entonces un analisis comparativo de los distintos metodos de obtencion de hidrogeno, de las limitantes presentes y las perspectivas futuras para cada uno de ellos. Tambien se hace una profunda reflexion acerca del reto y la orientacion que deben tener las investigaciones cientificas y tecnologicas para proponer al hidrogeno (o al biohidrogeno) como el combustible que deba sustituir a los combustibles fosiles durante el transcurso del siglo XXI

Mapeamento de radicais excitados e cinetica de reação para chamas de etanol

OpenAIRE

Leandro Henrique Benvenutti

1999-01-01

Resumo: Os principais objetivos deste trabalho foram o mapeamento da distribuição espacial das seguintes espécies no estado eletrônico excitado: OH*, HCO*, CH2O*, CH* e C2* , bem como o estudo da cinética de combustão para chamas explosivas de vapor de etanol e oxigênio. Para mapear as espécies excitadas na chama foi construído um sistema experimental com uma câmara de combustão em formato tubular, que possibilitou a obtenção de misturas gasosas com controle das pressões parciais dos gases e ...

Method and device for diagnosing and controlling combustion instabilities in internal combustion engines operating in or transitioning to homogeneous charge combustion ignition mode

Science.gov (United States)

Wagner, Robert M [Knoxville, TN; Daw, Charles S [Knoxville, TN; Green, Johney B [Knoxville, TN; Edwards, Kevin D [Knoxville, TN

2008-10-07

This invention is a method of achieving stable, optimal mixtures of HCCI and SI in practical gasoline internal combustion engines comprising the steps of: characterizing the combustion process based on combustion process measurements, determining the ratio of conventional and HCCI combustion, determining the trajectory (sequence) of states for consecutive combustion processes, and determining subsequent combustion process modifications using said information to steer the engine combustion toward desired behavior.

The Diesel Combustion Collaboratory: Combustion Researchers Collaborating over the Internet

Energy Technology Data Exchange (ETDEWEB)

C. M. Pancerella; L. A. Rahn; C. Yang

2000-02-01

The Diesel Combustion Collaborator (DCC) is a pilot project to develop and deploy collaborative technologies to combustion researchers distributed throughout the DOE national laboratories, academia, and industry. The result is a problem-solving environment for combustion research. Researchers collaborate over the Internet using DCC tools, which include: a distributed execution management system for running combustion models on widely distributed computers, including supercomputers; web-accessible data archiving capabilities for sharing graphical experimental or modeling data; electronic notebooks and shared workspaces for facilitating collaboration; visualization of combustion data; and video-conferencing and data-conferencing among researchers at remote sites. Security is a key aspect of the collaborative tools. In many cases, the authors have integrated these tools to allow data, including large combustion data sets, to flow seamlessly, for example, from modeling tools to data archives. In this paper the authors describe the work of a larger collaborative effort to design, implement and deploy the DCC.

Celdas combustibles: una opción para la transformación descentralizada de energía

Directory of Open Access Journals (Sweden)

Julio Alberto Gavilán Yodú

2011-02-01

Full Text Available La solución a los problemas energéticos actuales y al progresivo deterioro del medio ambiente está estrechamenterelacionada con la elección de sistemas energéticos alternativos que sean capaces de garantizar el desarrollosostenible de todos los países. La producción descentralizada de energía, fundamentada con acierto por losdefensores del denominado camino energético suave o el camino del Sol, permite la transformación de energíacon tecnologías preferentemente no contaminantes en el lugar de consumo. Con esto se reducirían de modoconsiderable las pérdidas energéticas ocasionadas por los procesos de transmisión y distribución. La celdacombustible constituye la tecnología de mayor potencial para revolucionar el panorama energético en este siglo.Como transformador electroquímico, la conversión energética máxima posible se define por la energía libre dereacción en un régimen de temperatura relativamente bajo. En este trabajo se realiza un análisis de los diferentestipos de celdas combustibles y se caracteriza el estado actual de esta tecnología. Además, se analiza el usodel hidrógeno solar en celdas combustibles.  The solution to the actual energy problems and to the progressive damage of the environment is closely relatedwith the election of alternative energy systems that it be able to guarantee the sustainable development of all thecountries. The decentralized energy production, based with success by the defenders of the one denominatedsoft energy way or Sun way, allows the energy transformation with technologies preferably not pollutants in theplace of  consumption. It would decrease in a considerable way the energy losses caused by the transmissionprocesses and distribution. The fuel cell constitutes the technology of more potential to revolutionize the energypanorama in this century. As electrochemical transformer, the possible maximum energy conversion is definedfor the free energy of reaction in a relatively

PRIBIC Application; Aplicacion para la Monitorizacion de una Planta Experimental de Combustion de Biomasa

Energy Technology Data Exchange (ETDEWEB)

Alonso, P.; Barcala Rivas, J. M.

2002-07-01

PRIBIC pant (Pollutants Reduction In small Blomass Combustion systems) at CEDER is a facility specifically designed to do biomass combustion tests. In these tests is necessary to known the values of different sensors in real time. With this information the PRIBIC plant is regulated to its optimum point of work and it's possible to follow the operation criteria and get test objectives. Different electronic instruments record information about the plant operation. A software application was developed to let a centralized monitorization of that information. the application communicates with the instrumentation, recovers data, lets operators see data in real time and saves the information in files. An important part of this document describes that application, and some considerations to generalize this kind of developments to other Experimental Plants, including cost estimations. Descriptions of plants, analysis of the problem, result evaluations, and conclusions can also be found in the document. (Author) 13 refs.

Gas phase enthalpies of formation of nitrobenzamides using combustion calorimetry and thermal analysis

International Nuclear Information System (INIS)

Ximello, Arturo; Flores, Henoc; Rojas, Aarón; Adriana Camarillo, E.; Patricia Amador, M.

2014-01-01

Graphical abstract: - Highlights: • Formation enthalpies of the nitrobenzamides were derived from combustion calorimetry. • Enthalpies of vaporisation and sublimation were calculated by thermogravimetry. • From gas phase enthalpies of formation the stability of the isomers is studied. • Stability of isomers is not driven by a steric hindrance between functional groups. - Abstract: The standard molar energies of combustion of 2-nitrobenzamide, 3-nitrobenzamide and 4-nitrobenzamide were determined with an isoperibolic, static-bomb, combustion calorimeter. From the combustion results, the standard molar enthalpies of combustion and formation for these compounds in the condensed phase at T = 298.15 K were derived. Subsequently, to determine the enthalpies of sublimation, the vapour pressure data as a function of the temperature for the compounds under investigation were estimated using thermogravimetry by applying Langmuir’s equation, and the enthalpies of vaporisation were derived. Standard enthalpies of fusion were measured by differential scanning calorimetry then added to those of vaporisation to obtain reliable results for the enthalpy of sublimation. From the combustion and sublimation data, the gas phase enthalpies of formation were determined to be (−138.9 ± 3.5) kJ · mol −1 , (−122.9 ± 2.9) kJ · mol −1 and (−108.5 ± 3.7) kJ · mol −1 for the ortho, meta and para isomers of nitrobenzamide, respectively. The meaning of these results with regard to the enthalpic stability of these molecular structures is discussed herein

New class of combustion processes

International Nuclear Information System (INIS)

Merzhanov, A.G.; Borovinskaya, I.P.

1975-01-01

A short review is given of the results of work carried out since 1967 on studying the combustion processes caused by the interaction of chemical elements in the condensed phase and leading to the formation of refractory compounds. New phenomena and processes are described which are revealed when investigating the combustion of the systems of this class, viz solid-phase combustion, fast combustion in the condensed phase, filtering combustion, combustion in liquid nitrogen, spinning combustion, self-oscillating combustion, and repeated combustion. A new direction in employment of combustion processes is discussed, viz. a self-propagating high-temperature synthesis of refractory nitrides, carbides, borides, silicides and other compounds

Experimental validation for combustion analysis of GOTHIC code in 2-dimensional combustion chamber

International Nuclear Information System (INIS)

Lee, J. W.; Yang, S. Y.; Park, K. C.; Jung, S. H.

2002-01-01

In this study, the prediction capability of GOTHIC code for hydrogen combustion phenomena was validated with the results of two-dimensional premixed hydrogen combustion experiment executed by Seoul National University. The experimental chamber has about 24 liter free volume (1x0.024x1 m 3 ) and 2-dimensional rectangular shape. The test were preformed with 10% hydrogen/air gas mixture and conducted with combination of two igniter positions (top center, top corner) and two boundary conditions (bottom full open, bottom right half open). Using the lumped parameter and mechanistic combustion model in GOTHIC code, the SNU experiments were simulated under the same conditions. The GOTHIC code prediction of the hydrogen combustion phenomena did not compare well with the experimental results. In case of lumped parameter simulation, the combustion time was predicted appropriately. But any other local information related combustion phenomena could not be obtained. In case of mechanistic combustion analysis, the physical combustion phenomena of gas mixture were not matched experimental ones. In boundary open cases, the GOTHIC predicted very long combustion time and the flame front propagation could not simulate appropriately. Though GOTHIC showed flame propagation phenomenon in adiabatic calculation, the induction time of combustion was still very long compare with experimental results. Also, it was found that the combustion model of GOTHIC code had some weak points in low concentration of hydrogen combustion simulation

Nixtamalización de cinco variedades de maíz con diferente dureza de grano: impacto en consumo de combustible y cambios fisicoquímicos

OpenAIRE

Roque-Maciel, Laura; Arámbula-Villa, Gerónimo; López-Espíndola, Mirna; Ortiz-Laurel, Hipólito; Carballo-Carballo, Aquiles; Herrera-Corredor, J. Andrés

2016-01-01

Resumen La nixtamalización causa en el grano de maíz cambios físicos, químicos y reológicos que afectan la calidad de la masa y la tortilla. La nixtamalización tradicional de maíz, realizada principalmente en contenedores abiertos, presenta una muy baja utilización de la energía requerida para este proceso, porque puede usar hasta 70 % más del combustible necesario. La correcta selección de los maíces para nixtamalizar contribuye en la calidad de las tortillas y el ahorro de combustible. El o...

Preliminary assessment of combustion modes for internal combustion wave rotors

Science.gov (United States)

Nalim, M. Razi

1995-01-01

Combustion within the channels of a wave rotor is examined as a means of obtaining pressure gain during heat addition in a gas turbine engine. Several modes of combustion are considered and the factors that determine the applicability of three modes are evaluated in detail; premixed autoignition/detonation, premixed deflagration, and non-premixed compression ignition. The last two will require strong turbulence for completion of combustion in a reasonable time in the wave rotor. The compression/autoignition modes will require inlet temperatures in excess of 1500 R for reliable ignition with most hydrocarbon fuels; otherwise, a supplementary ignition method must be provided. Examples of combustion mode selection are presented for two core engine applications that had been previously designed with equivalent 4-port wave rotor topping cycles using external combustion.

Dissolução do calcário no processo de dessulfurização de gases de combustão

OpenAIRE

Santos, Fabiane Binsfeld Ferreira dos

2007-01-01

Tese (doutorado) - Universidade Federal de Santa Catarina, Centro Tecnológico. Programa de Pós-Graduação em Engenharia Química. O dióxido de enxofre é reconhecido por seu efeito danoso à saúde humana e ao ambiente, por conduzir à chuva ácida. Para reduzir a emissão de SO2 nos gases produzidos pela combustão do carvão, podem-se empregar combustíveis de alta qualidade, com baixo conteúdo em enxofre, alternativa nem sempre viável, ou utilizar o processo de dessulfurização dos gases de combust...

Desempenho de misturas pré-aquecidas de óleo de soja cru e diesel como combustível para motores agrícolas Performance of preheated crude soybean oil-diesel blends as fuel in agricultural engines

Directory of Open Access Journals (Sweden)

José Fernando Schlosser

2007-10-01

Full Text Available O óleo de soja é um dos óleos vegetais que têm potencial de uso como combustível para motores diesel, pois é renovável, seguro e de fácil utilização. Em temperatura ambiente, o óleo cru apresenta uma viscosidade cerca de dez vezes maior que a do óleo diesel. Para reduzir a viscosidade do óleo de soja a níveis aceitáveis, é necessária uma temperatura de aquecimento em torno de aproximadamente 60°C ou misturá-lo com óleo diesel. O objetivo deste estudo foi avaliar o desempenho do óleo de soja cru e suas misturas com óleo diesel, pré-aquecidas antes da bomba injetora entre 57°C e 68°C, como combustível para motores diesel. O desempenho das misturas combustíveis foi avaliado num motor monocilíndrico de injeção indireta e comparado com o obtido pelo óleo diesel. Os ensaios de curta duração foram conduzidos entre 1.800 e 2.800rpm, sob condição de plena carga em dinamômetro hidráulico. Ensaios realizados a 68°C apresentaram sempre os melhores valores para torque, potência e consumo específico de combustível do que a 57°C. Uma mistura composta por 70% de óleo de soja e 30% de óleo diesel, aquecida a 68°C, apresentou os melhores resultados.Crude soybean oil is one of the vegetable oils that have potential for use as fuel for diesel engines. Soybean oil is renewable, and is safe and easy to handle. At room temperature crude oil has a viscosity about ten times higher than that of diesel oil. To lower soybean oil's viscosity to the acceptable levels a heating temperature at least 60°C is needed or blending with diesel fuel. The objective of this study was evaluating the soybean oil and blends performance as a fuel for diesel engines. On both crude soybean oil and soybean oil blends were used pre-heating temperature levels on the range between 57°C and 68°C, before fuel pump. The performance of the fuel blends were evaluated in a single cylinder indirect injection diesel engine and compared with the performance

Combustion modeling in internal combustion engines

Science.gov (United States)

Zeleznik, F. J.

1976-01-01

The fundamental assumptions of the Blizard and Keck combustion model for internal combustion engines are examined and a generalization of that model is derived. The most significant feature of the model is that it permits the occurrence of unburned hydrocarbons in the thermodynamic-kinetic modeling of exhaust gases. The general formulas are evaluated in two specific cases that are likely to be significant in the applications of the model.

A predictive model of natural gas mixture combustion in internal combustion engines

Directory of Open Access Journals (Sweden)

Henry Espinoza

2007-05-01

Full Text Available This study shows the development of a predictive natural gas mixture combustion model for conventional com-bustion (ignition engines. The model was based on resolving two areas; one having unburned combustion mixture and another having combustion products. Energy and matter conservation equations were solved for each crankshaft turn angle for each area. Nonlinear differential equations for each phase’s energy (considering compression, combustion and expansion were solved by applying the fourth-order Runge-Kutta method. The model also enabled studying different natural gas components’ composition and evaluating combustion in the presence of dry and humid air. Validation results are shown with experimental data, demonstrating the software’s precision and accuracy in the results so produced. The results showed cylinder pressure, unburned and burned mixture temperature, burned mass fraction and combustion reaction heat for the engine being modelled using a natural gas mixture.

Boiler using combustible fluid

Science.gov (United States)

Baumgartner, H.; Meier, J.G.

1974-07-03

A fluid fuel boiler is described comprising a combustion chamber, a cover on the combustion chamber having an opening for introducing a combustion-supporting gaseous fluid through said openings, means to impart rotation to the gaseous fluid about an axis of the combustion chamber, a burner for introducing a fluid fuel into the chamber mixed with the gaseous fluid for combustion thereof, the cover having a generally frustro-conical configuration diverging from the opening toward the interior of the chamber at an angle of between 15/sup 0/ and 55/sup 0/; means defining said combustion chamber having means defining a plurality of axial hot gas flow paths from a downstream portion of the combustion chamber to flow hot gases into an upstream portion of the combustion chamber, and means for diverting some of the hot gas flow along paths in a direction circumferentially of the combustion chamber, with the latter paths being immersed in the water flow path thereby to improve heat transfer and terminating in a gas outlet, the combustion chamber comprising at least one modular element, joined axially to the frustro-conical cover and coaxial therewith. The modular element comprises an inner ring and means of defining the circumferential, radial, and spiral flow paths of the hot gases.

40 CFR 51.918 - Can any SIP planning requirements be suspended in 8-hour ozone nonattainment areas that have air...

Science.gov (United States)

2010-07-01

... suspended in 8-hour ozone nonattainment areas that have air quality data that meets the NAAQS? 51.918 Section 51.918 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS... 8-hour Ozone National Ambient Air Quality Standard § 51.918 Can any SIP planning requirements be...

Análise termodinâmica de um ciclo de potência com célula a combustível sofc e turbina a vapor - DOI: 10.4025/actascitechnol.v28i1.1287

Directory of Open Access Journals (Sweden)

Alexandre Sordi

2006-03-01

Full Text Available O objetivo deste artigo foi realizar a análise termodinâmica de um sistema híbrido, SOFC / ST (célula a combustível tipo SOFC e turbina a vapor ST. O combustível considerado para a análise foi o gás metano (biogás produzido por meio da digestão anaeróbica de resíduos orgânicos. A metodologia utilizada foi o balanço de energia do sistema SOFC / ST, considerando a reforma interna do metano na célula a combustível, de forma a obter a sua eficiência elétrica. O resultado foi comparado a um ciclo combinado convencional de turbina a gás e turbina a vapor (GT / ST para potências entre 10 MW e 30 MW. A eficiência do sistema híbrido SOFC / ST variou de 61% a 66% em relação ao poder calorífico do metano; e a eficiência do ciclo combinado GT / ST variou de 41% a 55% para o mesmo intervalo de potência. Para geração distribuída a célula a combustível SOFC é a tecnologia mais eficiente.

HERCULES Advanced Combustion Concepts Test Facility: Spray/Combustion Chamber

Energy Technology Data Exchange (ETDEWEB)

Herrmann, K. [Eidgenoessische Technische Hochschule (ETH), Labor fuer Aerothermochemie und Verbrennungssysteme, Zuerich (Switzerland)

2004-07-01

This yearly report for 2004 on behalf of the Swiss Federal Office of Energy (SFOE) at the Laboratory for Aero-thermochemistry and Combustion Systems at the Federal Institute of Technology ETH in Zurich, Switzerland, presents a review of work being done within the framework of HERCULES (High Efficiency R and D on Combustion with Ultra Low Emissions for Ships) - the international R and D project concerning new technologies for ships' diesels. The work involves the use and augmentation of simulation models. These are to be validated using experimental data. The report deals with the development of an experimental set-up that will simulate combustion in large two-stroke diesel engines and allow the generation of reference data. The main element of the test apparatus is a spray / combustion chamber with extensive possibilities for optical observation under variable flow conditions. The results of first simulations confirm concepts and shall help in further work on the project. The potential offered by high-speed camera systems was tested using the institute's existing HTDZ combustion chamber. Further work to be done is reviewed.

Effect of the synthetic zeolite modification on its physicochemical and catalytic properties in the preparation of the catalysts effectively removing sulphur dioxide from exhaust gases

Directory of Open Access Journals (Sweden)

Marcewicz-Kuba Agnieszka

2016-06-01

Full Text Available This work presents the research results of the influence of modification deSONOx type catalyst of the sulfur dioxide emissions in the process of the hard coal combustion. The addition of zeolite catalysts modified by transition metal ions: V, Mg, activated by zinc sorbent with or without graphite addition caused the deeper burning of coal grains. The addition of the deSOx catalysts to the coal resulted in lowered sulphur dioxide emission. The addition of unmodified zeolite to coal during combustion reduced sulphur dioxide emission at about 5%. The modification of the support by both V and Mg reduced the amount of sulphur dioxide significantly. The obtained results of SO2 removal from exhaust gases were from 34.5% for Sip/Mg to 68.3% for Sip/V.

El biodiesel de aceite de higuerilla como combustible alternativo para motores diesel

OpenAIRE

ALIRIO BENAVIDES; PEDRO BENJUMEA; VESELINA PASHOVA

2007-01-01

En este artículo se presenta un estudio experimental sobre la producción y utilización del biodiesel de aceite de higuerilla. El máximo rendimiento de metilésteres en la reacción de transesterificación del aceite de higuerilla usado se obtiene bajo las siguientes condiciones: temperatura ambiente, una relación molar metanol/aceite de 9 y una concentración de catalizador de 0.8%. El biodiesel de aceite de higuerilla puede ser mezclado con el combustible diesel convencional derivado del petróle...

EL BIODIESEL DE ACEITE DE HIGUERILLA COMO COMBUSTIBLE ALTERNATIVO PARA MOTORES DIESEL

OpenAIRE

BENAVIDES, ALIRIO; BENJUMEA, PEDRO; PASHOVA, VESELINA

2007-01-01

En este artículo se presenta un estudio experimental sobre la producción y utilización del biodiesel de aceite de higuerilla. El máximo rendimiento de metilésteres en la reacción de transesterificación del aceite de higuerilla usado se obtiene bajo las siguientes condiciones: temperatura ambiente, una relación molar metanol/aceite de 9 y una concentración de catalizador de 0.8%. El biodiesel de aceite de higuerilla puede ser mezclado con el combustible diesel convencional derivado del petróle...

Development and feasibility of a Swallowing intervention Package (SiP) for patients receiving radiotherapy treatment for head and neck cancer-the SiP study protocol.

Science.gov (United States)

Wells, Mary; King, Emma; Toft, Kate; MacAulay, Fiona; Patterson, Joanne; Dougall, Nadine; Hulbert-Williams, Nick; Boa, Sally; Slaven, Eleanor; Cowie, Julie; McGarva, John; Niblock, Patricia Gail; Philp, Julie; Roe, Justin

2016-01-01

Head and neck cancer (HNC) is the sixth most common cancer worldwide, and the functional, psychological and social consequences of HNC cancer and its treatment can be severe and chronic. Dysphagia (swallowing problems) affects up to two thirds of patients undergoing combined chemoradiotherapy. Recent reviews suggest that prophylactic swallowing exercises may improve a range of short- and long-term outcomes; however, the importance of psychological and behavioural factors on adherence to swallowing exercises has not been adequately studied. This study aims to develop and test the feasibility of a Swallowing intervention Package (SiP) designed in partnership with patients, speech and language therapists (SLTs) and other members of the head and neck multi-disciplinary team (MDT), for patients undergoing chemoradiotherapy (CRT) or radiotherapy (RT) for head and neck cancer. This feasibility study uses quantitative and qualitative research methods, within a quasi-experimental design, to assess whether patients will tolerate and adhere to the SiP intervention, which aspects of the intervention can be implemented and which cannot, whether treatment fidelity can be achieved across different contexts, whether study processes and outcome measures will be feasible and acceptable and to what extent the intervention is likely to have an impact on swallowing dysfunction and quality of life. Patients are being recruited from five sites in Scotland and England (three interventions and two usual care). The SLT based in the relevant intervention centre teaches the exercise programme and provides supporting materials. A combination of patient-reported outcome measures (PROMs), adherence measures and clinical swallowing assessments are used prior to intervention (baseline), at the end of treatment, 3 and 6 months post-treatment. This collaborative study has taken a unique approach to the development of a patient-centred and evidence-based swallowing intervention. The introduction of

Gradual combustion - method for nitrogen oxide suppression during brown coal combustion

Energy Technology Data Exchange (ETDEWEB)

Kotler, V.P.; Verzakov, V.N.; Lobov, T.V.

1990-10-01

Discusses combustion of brown coal in BKZ-500-140-1 boilers and factors that influence emission of nitrogen oxides. Temperature distribution in the furnace was evaluated. Effects of burner position, burner number and burner type as well as air excess ratio on chemical reactions during brown coal combustion, formation of nitrogen oxides and their emission were comparatively evaluated. Analyses showed that by optimum arrangement of burners and selecting the optimum air excess ratio a part of nitrogen oxides formed during the initial phase of combustion was reduced to molecular nitrogen in the second phase. On the basis of evaluations the following recommendations for furnace design are made: use of straight-flow burners characterized by a reduced mixing ratio with secondary air, parallel arrangement of burners which guarantees mixing of the combustion products from the burners with stable and unstable combustion (products of incomplete coal combustion), reducing the air excess ratio to below 1.0. 5 refs.

Sistema ultra-sonico para medida volumetrica

OpenAIRE

Isaias Ferreira da Silva

1999-01-01

Resumo: Um método inovador para a medida do volume de um líquido dentro de um recipiente fechado é proposto. A motivação deste trabalho é a aplicação do método para a medida do volume de combustível dentro de um tanque de automóvel. Este método se baseia no fenômeno de reverberação sonora que relaciona o tempo de decaimento da intensidade do som dentro de um ambiente com o seu volume. Este tempo, conhecido como tempo de reverberação, está associado ao volume vazio dentro do recipiente, ao mat...

Enhancing electron transport in Si:P delta-doped devices by rapid thermal anneal

International Nuclear Information System (INIS)

Goh, K. E. J.; Augarten, Y.; Oberbeck, L.; Simmons, M. Y.

2008-01-01

We address the use of rapid thermal anneal (RTA) to enhance electron mobility and phase coherent transport in Si:P δ-doped devices encapsulated by low temperature Si molecular beam epitaxy while minimizing dopant diffusion. RTA temperatures of 500-700 deg. C were applied to δ-doped layers encapsulated at 250 deg. C. From 4.2 K magnetotransport measurements, we find that the improved crystal quality after RTA increases the mobility/mean free path by ∼40% and the phase coherence length by ∼25%. Our results suggest that the initial capping layer has near optimal crystal quality and transport improvement achieved by a RTA is limited

The Italian version of the 92-item Prodromal Questionnaire: Concurrent validity with the SIPS and factor analysis in a sample of 258 outpatients aged 11-36years.

Science.gov (United States)

Kotzalidis, Georgios D; Solfanelli, Andrea; Piacentino, Daria; Savoja, Valeria; Fiori Nastro, Paolo; Curto, Martina; Lindau, Juliana Fortes; Masillo, Alice; Brandizzi, Martina; Fagioli, Francesca; Raballo, Andrea; Gebhardt, Eva; Preti, Antonio; D'Alema, Marco; Fucci, Maria Rosa; Miletto, Roberto; Andropoli, Daniela; Leccisi, Donato; Girardi, Paolo; Loewy, Rachel L; Schultze-Lutter, Frauke

2017-11-01

Current early screeners for psychosis-risk states have still to prove ability in identifying at-risk individuals. Among screeners, the 92-item Prodromal Questionnaire (PQ-92) is often used. We aimed to assess the validity of its Italian translation in a large Italian adolescent and young adult help-seeking sample. We included all individuals aged 12-36years seeking help at psychiatric mental health services in a large semirural Roman area (534,600 population) who accepted to participate. Participants completed the Italian version of the PQ-92 and were subsequently assessed with the Structured Interview of Prodromal/Psychosis-Risk Syndromes (SIPS). We examined diagnostic accuracy (sensitivity, specificity, positive and negative predictive values, and positive and negative likelihood ratios) and content, concurrent, and convergent validity between PQ-92 and SIPS using Cronbach's alpha, Cohen's kappa, and Spearman's rho, respectively. We tested the validity of adopted cut-offs through Receiver Operating Characteristic (ROC) curves plotted against SIPS diagnoses and the instrument's factor-structure through Principal Component Analysis. PQ-92 showed high internal consistency, acceptable diagnostic accuracy and concurrent validity, and excellent convergent validity. ROC analyses pointed to scores of 18 on the Positive subscale and 36 on the total PQ-92 as best cut-offs. The Scree-test identified a four-factor solution as fitting best. Psychometric properties of Italian PQ-92 were satisfactory. Optimal cut-offs were confirmed at ≥18 on the positive subscale, but at ≥36 on the total scale was able to identify more SIPS-positive cases. Copyright © 2017 Elsevier B.V. All rights reserved.

Uncertainties in hydrogen combustion

International Nuclear Information System (INIS)

Stamps, D.W.; Wong, C.C.; Nelson, L.S.

1988-01-01

Three important areas of hydrogen combustion with uncertainties are identified: high-temperature combustion, flame acceleration and deflagration-to-detonation transition, and aerosol resuspension during hydrogen combustion. The uncertainties associated with high-temperature combustion may affect at least three different accident scenarios: the in-cavity oxidation of combustible gases produced by core-concrete interactions, the direct containment heating hydrogen problem, and the possibility of local detonations. How these uncertainties may affect the sequence of various accident scenarios is discussed and recommendations are made to reduce these uncertainties. 40 references

The combustion behavior of diesel/CNG mixtures in a constant volume combustion chamber

Science.gov (United States)

Firmansyah; Aziz, A. R. A.; Heikal, M. R.

2015-12-01

The stringent emissions and needs to increase fuel efficiency makes controlled auto-ignition (CAI) based combustion an attractive alternative for the new combustion system. However, the combustion control is the main obstacles in its development. Reactivity controlled compression ignition (RCCI) that employs two fuels with significantly different in reactivity proven to be able to control the combustion. The RCCI concept applied in a constant volume chamber fuelled with direct injected diesel and compressed natural gas (CNG) was tested. The mixture composition is varied from 0 - 100% diesel/CNG at lambda 1 with main data collection are pressure profile and combustion images. The results show that diesel-CNG mixture significantly shows better combustion compared to diesel only. It is found that CNG is delaying the diesel combustion and at the same time assisting in diesel distribution inside the chamber. This combination creates a multipoint ignition of diesel throughout the chamber that generate very fast heat release rate and higher maximum pressure. Furthermore, lighter yellow color of the flame indicates lower soot production in compared with diesel combustion.

Combustion characteristics and air pollutant formation during oxy-fuel co-combustion of microalgae and lignite.

Science.gov (United States)

Gao, Yuan; Tahmasebi, Arash; Dou, Jinxiao; Yu, Jianglong

2016-05-01

Oxy-fuel combustion of solid fuels is seen as one of the key technologies for carbon capture to reduce greenhouse gas emissions. The combustion characteristics of lignite coal, Chlorella vulgaris microalgae, and their blends under O2/N2 and O2/CO2 conditions were studied using a Thermogravimetric Analyzer-Mass Spectroscopy (TG-MS). During co-combustion of blends, three distinct peaks were observed and were attributed to C. vulgaris volatiles combustion, combustion of lignite, and combustion of microalgae char. Activation energy during combustion was calculated using iso-conventional method. Increasing the microalgae content in the blend resulted in an increase in activation energy for the blends combustion. The emissions of S- and N-species during blend fuel combustion were also investigated. The addition of microalgae to lignite during air combustion resulted in lower CO2, CO, and NO2 yields but enhanced NO, COS, and SO2 formation. During oxy-fuel co-combustion, the addition of microalgae to lignite enhanced the formation of gaseous species. Copyright © 2016 Elsevier Ltd. All rights reserved.

Comparing architectural solutions of IPT application SDKs utilizing H.323 and SIP

Science.gov (United States)

Keskinarkaus, Anja; Korhonen, Jani; Ohtonen, Timo; Kilpelanaho, Vesa; Koskinen, Esa; Sauvola, Jaakko J.

2001-07-01

This paper presents two approaches to efficient service development for Internet Telephony. In first approach we consider services ranging from core call signaling features and media control as stated in ITU-T's H.323 to end user services that supports user interaction. The second approach supports IETF's SIP protocol. We compare these from differing architectural perspectives, economy of network and terminal development, and propose efficient architecture models for both protocols. In their design, the main criteria were component independence, lightweight operation and portability in heterogeneous end-to-end environments. In proposed architecture, the vertical division of call signaling and streaming media control logic allows for using the components either individually or combined, depending on the level of functionality required by an application.

Problems of radiation protection during SIP implementation on the Shelter

International Nuclear Information System (INIS)

Bogorad, V.I.; Litvinskaya, T.V.; Nikonov, D.A.

2001-01-01

One of the most urgent problems for today, during the SIP plans implementation of the Shelter transformation, is personnel radiation safety. The first of them assumes that a worker can be exposed to permitted annual dose during a short period of time with subsequent withdrawal of the person from radiation-hazardous activities. The second approach is based on the determination of derived dose limits that would provide for non-excess of the main limits on the assumption that a person is involved in radiation-hazardous work during the whole year. Radiation protection during practical activity should be formed on the basis of optimization principle. The optimization, in this case, implies that activities in the fields of ionizing radiation should be planned and performed in such way that, during their performance, the levels of individual doses and/or the quantity of exposed persons be as low as possible with taking into account the economic and social factors

In-core sipping method for the identification of failed fuel assemblies

International Nuclear Information System (INIS)

Wu Zhongwang; Zhang Yajun

2000-01-01

The failed fuel assembly identification system is an important safety system which ensures safe operations of reactor and immediate treatment of failed fuel rod cladding. The system uses an internationally recognized method to identify failed fuel assemblies in a reactor with fuel element cases. The in-core sipping method is customary used to identify failed fuel assemblies during refueling or after fuel rod cladding failure accidents. The test is usually performed after reactor shutdown by taking samples from each fuel element case while the cases are still in their original core positions. The sample activity is then measured to identify failed fuel assemblies. A failed fuel assembly identification system was designed for the NHR-200 based on the properties of the NHR-200 and national requirements. the design provides an internationally recognized level of safety to ensure the safety of NHR-200

Up-date on cyclone combustion and cyclone boilers

Energy Technology Data Exchange (ETDEWEB)

Carmo, Felipe Alfaia do; Nogueira, Manoel Fernandes Martins; Rocha, Rodrigo Carnera Castro da; Gazel, Hussein Felix; Martins, Diego Henrique dos Reis [Universidade Federal do Para (UFPA), Belem, PA (Brazil). Campus Universitario Jose da Silveira Netto], E-mails: mfmn@ufpa.br, mfmn@ufpa.br

2010-07-01

The boiler concept has been around for more than 70 years, and there are many types available. Boilers provide steam or hot water for industrial and commercial use. The Federal University of Para (UFPA) through the research group EBMA (Energy,Biomass and Environment) has been developing cyclonic furnace with a water wall, a boiler, aiming to use regional timbers (sawdust) and agro-industries residues as fuel to produce steam to be used in industrial processes as well as in power generation,. The use of cyclonic combustion for burning waste instead of burning in a fixed bed is mainly due to two factors efficiency improvement causing a more compact boiler and less risk of explosion, since their process does not generate an accumulation of volatile. Present state-of-art for commercial cyclone boilers has as set up a cyclone combustor with two combustion chambers, in fluid communication, where there ducts for supplying air and fuel directly into the first chamber and for forming a cyclonic flow pattern and a heat exchanger surrounding the second chamber for keeping low combustion temperature in both chambers. This paper shows the results of a literature review about design, construction and operation of cyclonic boilers using solid, liquid or gaseous fuel. This information has been used for the design of a cyclone boiler to be constructed at UFPA for research purposes and its basic concept is presented at the end of this article. (author)

Fuel and combustion stratification study of Partially Premixed Combustion

NARCIS (Netherlands)

Izadi Najafabadi, M.; Dam, N.; Somers, B.; Johansson, B.

2016-01-01

Relatively high levels of stratification is one of the main advantages of Partially Premixed Combustion (PPC) over the Homogeneous Charge Compression Ignition (HCCI) concept. Fuel stratification smoothens heat release and improves controllability of this kind of combustion. However, the lack of a

Maximal combustion temperature estimation

International Nuclear Information System (INIS)

Golodova, E; Shchepakina, E

2006-01-01

This work is concerned with the phenomenon of delayed loss of stability and the estimation of the maximal temperature of safe combustion. Using the qualitative theory of singular perturbations and canard techniques we determine the maximal temperature on the trajectories located in the transition region between the slow combustion regime and the explosive one. This approach is used to estimate the maximal temperature of safe combustion in multi-phase combustion models

Effect of Variant End of Injection Period on Combustion Process of Biodiesel Combustion

Directory of Open Access Journals (Sweden)

Khalid Amir

2016-01-01

Full Text Available Biodiesel is an alternative fuel as a replacement to the standard diesel fuel in combustion diesel engine. The biodiesel fuel has a significantly influences throughout the combustion process and exhaust emission. The purpose of this research is to investigate the combustion process behavior during the End of Injection (EOI period and operates under variant conditions using Rapid Compression Machine (RCM. Experimental of RCM is used to simulate a combustion process and combustion characteristics of diesel engine combustion. Three types of biodiesel blend which are B5, B10 and B15 were tested at several injection pressures of 80 MPa, 90 MPa and 130 MPa under different ambient temperatures, 750 K to 1100 K. The results of this study showed that the ignition delay slightly reduced with increasing the content of biodiesel blends from B5, B10 and B15 and became more shorten as the injection pressure been enhanced. As the injection pressure increased, the behavior of combustion pressure at end of injection is reduced, radically increased the NOX emission. It is noted that the process of combustion at the end of injection increased as the ambient temperature is rising. In fact, higher initial ambient temperature improved the fuel atomization and mixing process. Under the biodiesel combustion with higher ambient temperature condition, the exhaust emission of CO, O2, and HC became less but increased in NOX emission. Besides, increased in blends of biodiesel ratio are found to enhance the combustion process, resulted a decreased in HC emissions.

Jet plume injection and combustion system for internal combustion engines

Science.gov (United States)

Oppenheim, Antoni K.; Maxson, James A.; Hensinger, David M.

1993-01-01

An improved combustion system for an internal combustion engine is disclosed wherein a rich air/fuel mixture is furnished at high pressure to one or more jet plume generator cavities adjacent to a cylinder and then injected through one or more orifices from the cavities into the head space of the cylinder to form one or more turbulent jet plumes in the head space of the cylinder prior to ignition of the rich air/fuel mixture in the cavity of the jet plume generator. The portion of the rich air/fuel mixture remaining in the cavity of the generator is then ignited to provide a secondary jet, comprising incomplete combustion products which are injected into the cylinder to initiate combustion in the already formed turbulent jet plume. Formation of the turbulent jet plume in the head space of the cylinder prior to ignition has been found to yield a higher maximum combustion pressure in the cylinder, as well as shortening the time period to attain such a maximum pressure.

Path planning during combustion mode switch

Science.gov (United States)

Jiang, Li; Ravi, Nikhil

2015-12-29

Systems and methods are provided for transitioning between a first combustion mode and a second combustion mode in an internal combustion engine. A current operating point of the engine is identified and a target operating point for the internal combustion engine in the second combustion mode is also determined. A predefined optimized transition operating point is selected from memory. While operating in the first combustion mode, one or more engine actuator settings are adjusted to cause the operating point of the internal combustion engine to approach the selected optimized transition operating point. When the engine is operating at the selected optimized transition operating point, the combustion mode is switched from the first combustion mode to the second combustion mode. While operating in the second combustion mode, one or more engine actuator settings are adjusted to cause the operating point of the internal combustion to approach the target operating point.

Combustion, detonation, shock waves. Proceedings of the Zel'dovich memorial - International conference on combustion. Volume 1

International Nuclear Information System (INIS)

Merzhanov, A.G.; Frolov, S.M.

1995-01-01

This book contains lectures by the experts in various fields of modern research in combustion, detonation and shock waves, presented at the Zel'dovich memorial - International conference on combustion dedicated to the 80-th birthday of academician Ya.B. Zel'dovich. There are eight chapters discussing the state-of-the-art in combustion kinetics, ignition and steady-state flame propagation, diffusion and heterogeneous combustion, turbulent combustion, unsteady combustion, detonation, combustion and detonation analogies, intense shock waves and extreme states of matter [ru

Alternative analysis to increase the power in combined-cycle power plants; Analisis de alternativas para el incremento de potencia en plantas termoelectricas de Ciclo Combinado

Energy Technology Data Exchange (ETDEWEB)

Pacheco Cruz, Hector; Arriola Medellin, Alejandro M. [Gerencia de Procesos Termicos, Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)]. E-mail: hpacheco@iie.org.mx; aarriola@iie.org.mx

2010-11-15

The electricity industry traditionally had two thermodynamic cycles for power generation: conventional steam turbine (Rankine cycle) used to supply a base load during the day, and gas turbines (Brayton cycle), for its speed response, normally used to cover peak loads. However, to provide variable peak loads, the gas turbine, as a volumetric machine is affected by the change in air density by changing the combustion temperature. This paper shows the scheme of integration of both systems, that it's known as combined cycle and the different options that would have these power plants, to maintain or increase their power in variable ambient conditions. It analyzes different options, such as: 1. Supplementary fire in the stove. 2. Air cooling intake in the gas turbine (evaporation system or mechanical system). 3. Steam injection in the combustion chamber. [Spanish] La industria electrica tradicionalmente a contado con dos ciclos termodinamicos para generacion electrica: las turbinas convencionales de vapor (ciclo de Rankine) se utilizan para suministrar una carga base durante el dia, y las turbinas de gas (ciclo de Brayton), por su rapidez de respuesta, se utilizan normalmente para cubrir las cargas pico. Sin embargo, para suministrar las cargas variables pico, la turbina a gas, por ser una maquina volumetrica, se ve afectada por el cambio de la densidad del aire de combustion al cambiar la temperatura ambiente. En este trabajo se muestra el esquema de integracion de ambos sistemas, en lo que se conoce como ciclo combinado y las diferentes opciones que tendrian estas plantas de generacion electrica para mantener o incrementar su potencia en condiciones ambiente variable. Para ello se analizan diferentes opciones, tales como: 1.- Combustion suplementaria en el recuperador de calor. 2.- Enfriamiento del aire de admision a la turbina de gas (mediante un sistema de evaporacion o mediante un sistema mecanico). 3.- Inyeccion de vapor a la camara de combustion. Palabras

Fuels and Combustion

KAUST Repository

Johansson, Bengt

2016-08-17

This chapter discusses the combustion processes and the link to the fuel properties that are suitable for them. It describes the basic three concepts, including spark ignition (SI) and compression ignition (CI), and homogeneous charge compression ignition (HCCI). The fuel used in a CI engine is vastly different from that in an SI engine. In an SI engine, the fuel should sustain high pressure and temperature without autoignition. Apart from the dominating SI and CI engines, it is also possible to operate with a type of combustion: autoignition. With HCCI, the fuel and air are fully premixed before combustion as in the SI engine, but combustion is started by the increased pressure and temperature during the compression stroke. Apart from the three combustion processes, there are also a few combined or intermediate concepts, such as Spark-Assisted Compression Ignition (SACI). Those concepts are discussed in terms of the requirements of fuel properties.

Fuels and Combustion

KAUST Repository

Johansson, Bengt

2016-01-01

This chapter discusses the combustion processes and the link to the fuel properties that are suitable for them. It describes the basic three concepts, including spark ignition (SI) and compression ignition (CI), and homogeneous charge compression ignition (HCCI). The fuel used in a CI engine is vastly different from that in an SI engine. In an SI engine, the fuel should sustain high pressure and temperature without autoignition. Apart from the dominating SI and CI engines, it is also possible to operate with a type of combustion: autoignition. With HCCI, the fuel and air are fully premixed before combustion as in the SI engine, but combustion is started by the increased pressure and temperature during the compression stroke. Apart from the three combustion processes, there are also a few combined or intermediate concepts, such as Spark-Assisted Compression Ignition (SACI). Those concepts are discussed in terms of the requirements of fuel properties.

Utilización de la zeolita para disminuir los gases tóxicos de los motores de combustión interna. // The utilization of Cuban zeolites in the decrease of toxic gases emissions of internal combustion engines.

Directory of Open Access Journals (Sweden)

J. L. Reyes González

2003-01-01

Full Text Available En el trabajo se presentan los resultados obtenidos al utilizar la zeolita natural cubana para la disminución de los gasestóxicos que los motores de combustión interna MCI. envían a la atmósfera. Los experimentos fueron realizados en bancosde pruebas de MCI. tanto para motores de carburación como para motores diesel. Obteniéndose eficiencias de disminucióndel CO del 80 %, del CnHm del 50% y el humo negro en un 90%. Se demuestra la importancia de la granulometría de lazeolita para esta eliminación y para mantener la potencia del motor dentro de rangos aceptables.Palabras claves: Toxicidad, zeolita, medio ambiente, filtros, gases de escape._______________________________________________________________________________Abstract.In this paper are presented the results of the utilization of Cuban zeolites in the decrease of toxic gas emissions toatmosphere of internal combustion engines, (MCI. The experiments were carried out in test bank for gasoline and dieselengines. The efficiency in the decrement of CO was of 80%, CnHm in 50%, and 90 % in soot. The size of the zeolitesparticle importance in the efficiency is demonstrated.Key words: Toxicity, zeolite, enviroment, filters, gas emissions.

Lump wood combustion process

Science.gov (United States)

Kubesa, Petr; Horák, Jiří; Branc, Michal; Krpec, Kamil; Hopan, František; Koloničný, Jan; Ochodek, Tadeáš; Drastichová, Vendula; Martiník, Lubomír; Malcho, Milan

2014-08-01

The article deals with the combustion process for lump wood in low-power fireplaces (units to dozens of kW). Such a combustion process is cyclical in its nature, and what combustion facility users are most interested in is the frequency, at which fuel needs to be stoked to the fireplace. The paper defines the basic terms such as burnout curve and burning rate curve, which are closely related to the stocking frequency. The fuel burning rate is directly dependent on the immediate thermal power of the fireplace. This is also related to the temperature achieved in the fireplace, magnitude of flue gas losses and the ability to generate conditions favouring the full burnout of the fuel's combustible component, which, at once ensures the minimum production of combustible pollutants. Another part of the paper describes experiments conducted in traditional fireplaces with a grate, at which well-dried lump wood was combusted.

Combustion Research Laboratory

Data.gov (United States)

Federal Laboratory Consortium — The Combustion Research Laboratory facilitates the development of new combustion systems or improves the operation of existing systems to meet the Army's mission for...

Combustion chemistry and formation of pollutants; Chimie de la combustion et formation des polluants

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-12-31

This book of proceedings reports on 7 papers on combustion chemistry and formation of pollutants presented during the workshop organized by the `Combustion and Flames` section of the French society of thermal engineers. The chemistry of combustion is analyzed in various situations such as: turbojet engines, spark ignition engines, industrial burners, gas turbines etc... Numerical simulation is used to understand the physico-chemical processes involved in combustion, to describe the kinetics of oxidation, combustion and flame propagation, and to predict the formation of pollutants. (J.S.)

Heavy metals behaviour during mono-combustion and co-combustion of sewage sludge

Energy Technology Data Exchange (ETDEWEB)

Lopes, M. Helena; Abelha, Pedro; Olieveira, J.F. Santos; Gulyurtlu, Ibrahim; Cabrita, Isabel [INETI-DEECA, Lisboa (Portugal)

2005-03-01

This paper presents the study of the combustion of granular dry sewage sludge performed on a pilot fluidized bed system. The results of mono-combustion of sludge and co-combustion with coal were compared with those of coal combustion for ash partitioning, the formation of gaseous pollutants and heavy metals behaviour. It was found that the mineral matter of sludge was essentially retained as bottom ashes. The production of fines ashes was small during the mono-combustion due to the tendency of coal to produce fine ashes which also contained unburned char. The degree of heavy metal volatilization was found to be slightly higher during co-combustion than in mono-combustion; however, most of them were retained in ashes and their emissions were found to be below the regulated levels. Hg was completely volatilized; however, during combustion trials involving coal it was captured by cyclone ashes at temperatures below 300 deg C. During sludge mono-combustion the retention of Hg in cyclone ashes containing low LOI was not enough to decrease emissions below the regulated levels; hence, it is necessary to install dedicated flue gas treatment for Hg removal. The leachability and ecotoxicity of sludge and ashes was compared with the new regulatory limits for landfill disposal in the EU. It was found that the release of organic matter and heavy metals found in the sludge was low from granular bed ashes; hence, except for sulphate release, bed ashes were converted into inert and non-ecotoxic materials. Ashes from test with limestone and cyclone ashes seemed to be more problematic because of pH effects and contamination with steel corrosion products. The recovery and reutilization of sludge bed ashes could, therefore, be possible, as long as the release of sulphate do not interfere with the process.

Twenty-fifth symposium (international) on combustion

International Nuclear Information System (INIS)

Anon.

1994-01-01

Approximately two-thirds of the papers presented at this conference are contained in this volume. The other one-third appear in special issues of ''Combustion and Flame'', Vol. 99, 1994 and Vol. 100, 1995. Papers are divided into the following sections: Supersonic combustion; Detonations and explosions; Internal combustion engines; Practical aspects of combustion; Incineration and wastes; Sprays and droplet combustion; Coal and organic solids combustion; Soot and polycyclic aromatic hydrocarbons; Reaction kinetics; NO x ; Turbulent flames; Turbulent combustion; Laminar flames; Flame spread, fire and halogenated fire suppressants; Global environmental effects; Ignition; Two-phase combustion; Solid propellant combustion; Materials synthesis; Microgravity; and Experimental diagnostics. Papers have been processed separately for inclusion on the data base

LES and RANS modeling of pulverized coal combustion in swirl burner for air and oxy-combustion technologies

International Nuclear Information System (INIS)

Warzecha, Piotr; Boguslawski, Andrzej

2014-01-01

Combustion of pulverized coal in oxy-combustion technology is one of the effective ways to reduce the emission of greenhouse gases into the atmosphere. The process of transition from conventional combustion in air to the oxy-combustion technology, however, requires a thorough investigations of the phenomena occurring during the combustion process, that can be greatly supported by numerical modeling. The paper presents the results of numerical simulations of pulverized coal combustion process in swirl burner using RANS (Reynolds-averaged Navier–Stokes equations) and LES (large Eddy simulation) methods for turbulent flow. Numerical simulations have been performed for the oxyfuel test facility located at the Institute of Heat and Mass Transfer at RWTH Aachen University. Detailed analysis of the flow field inside the combustion chamber for cold flow and for the flow with combustion using different numerical methods for turbulent flows have been done. Comparison of the air and oxy-coal combustion process for pulverized coal shows significant differences in temperature, especially close to the burner exit. Additionally the influence of the combustion model on the results has been shown for oxy-combustion test case. - Highlights: • Oxy-coal combustion has been modeled for test facility operating at low oxygen ratio. • Coal combustion process has been modeled with simplified combustion models. • Comparison of oxy and air combustion process of pulverized coal has been done. • RANS (Reynolds-averaged Navier–Stokes equations) and LES (large Eddy simulation) results for pulverized coal combustion process have been compared

High Frequency Combustion Instabilities of LOx/CH4 Spray Flames in Rocket Engine Combustion Chambers

NARCIS (Netherlands)

Sliphorst, M.

2011-01-01

Ever since the early stages of space transportation in the 1940’s, and the related liquid propellant rocket engine development, combustion instability has been a major issue. High frequency combustion instability (HFCI) is the interaction between combustion and the acoustic field in the combustion

Combustion Research Facility

Data.gov (United States)

Federal Laboratory Consortium — For more than 30 years The Combustion Research Facility (CRF) has served as a national and international leader in combustion science and technology. The need for a...

Method and apparatus for active control of combustion rate through modulation of heat transfer from the combustion chamber wall

Science.gov (United States)

Roberts, Jr., Charles E.; Chadwell, Christopher J.

2004-09-21

The flame propagation rate resulting from a combustion event in the combustion chamber of an internal combustion engine is controlled by modulation of the heat transfer from the combustion flame to the combustion chamber walls. In one embodiment, heat transfer from the combustion flame to the combustion chamber walls is mechanically modulated by a movable member that is inserted into, or withdrawn from, the combustion chamber thereby changing the shape of the combustion chamber and the combustion chamber wall surface area. In another embodiment, heat transfer from the combustion flame to the combustion chamber walls is modulated by cooling the surface of a portion of the combustion chamber wall that is in close proximity to the area of the combustion chamber where flame speed control is desired.

Fuel Combustion Laboratory | Transportation Research | NREL

Science.gov (United States)

Fuel Combustion Laboratory Fuel Combustion Laboratory NREL's Fuel Combustion Laboratory focuses on designs, using both today's technology and future advanced combustion concepts. This lab supports the combustion chamber platform for fuel ignition kinetics research, was acquired to expand the lab's

Sandia Combustion Research: Technical review

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-07-01

This report contains reports from research programs conducted at the Sandia Combustion Research Facility. Research is presented under the following topics: laser based diagnostics; combustion chemistry; reacting flow; combustion in engines and commercial burners; coal combustion; and industrial processing. Individual projects were processed separately for entry onto the DOE databases.

Inversión de modelos de simulación de la reflectividad para la estimación del estado hídrico del combustible vivo en matorrales y pastizales de la Argentina

OpenAIRE

Yebra Álvarez, Marta; Beget, María Eugenia; Oricchio, Patricia; Di Bella, Carlos

2010-01-01

En este trabajo se explora la posibilidad de estimar el contenido de humedad de los combustibles vivos (FMC) a partir de la inversión de los modelos de simulación de la refectividad a nivel de hoja (PROSPECT) y a nivel de dosel (SAILH), la utilización de imágenes de satélite (sensor MODIS) e información auxiliar medida en campo. La metodología propuesta para llevar a cabo la inversión se basa en técnicas de clasificación supervisada de imágenes, así como en técnicas de regresión múltiple. Dic...

Influência da adulteração de combustíveis no desempenho e na vida útil de motores de combustão interna de ignição por faísca de pequeno porte utilizados em motocicletas.

OpenAIRE

Luiz Vicente Figueira de Mello Filho

2009-01-01

Este trabalho tem como principal objetivo mostrar os efeitos do uso de gasolina adulterada em motores de pequena cilindrada em seus desempenhos e durabilidades. Para tanto, foram realizados ensaios comparativos em três motores carburados de aplicação em motocicletas, de mesmas séries. Estes motores consumiram gasolina C, padrão brasileiro de combustível para motores de ignição por faísca, e misturas desta gasolina com etanol hidratado carburante e solvente C-9. Os resultados mostram alteraçõe...

Membranas híbridas basadas en estireno-metacrilato-sílice y ácido fosfowolfrámico obtenidas por sol-gel para pilas de combustible de intercambio protónico (PEMFC

Directory of Open Access Journals (Sweden)

Mosa, J.

2007-10-01

Full Text Available Contrary to internal combustion engines, proton-exchange membrane fuel cells (PEMFC used in transportation operate with zero emissions of environmental pollutants. The increase of the operation temperature in PEMFC above 100°C is a great concern for the application of this type of cells in electric vehicles. Hybrid organic-inorganic membranes with nanosized interfaces can combine the main properties of their components to meet this objective. Styrene-methacrylate-silica membranes doped with phosphotungstic acid (PWA were prepared through acid catalyzed sol-gel process and free-radical copolymerization. Additionally, sulfonation processes of aromatic rings to produce attached SO3H groups were applied to increase the proton conductivity. The effect of sulfonation degree and PWA doping on the membrane properties such as chemical and thermal stability, water uptake, ion exchange capacity, and proton conductivity were investigated. The measurement of conductivity shows a general increase with rising temperatures and with the increasing of SO3H groups density, reaching a maximum value of 3.2 10-3 S/cm at 130ºC and 100%HR.

Comparadas con los motores de combustión interna, las pilas de combustible de intercambio de protones (PEMFC son capaces de operar sin emisiones de agentes contaminantes. El aumento de la temperatura de operación de la pila de combustible por encima de 100ºC es uno de los grandes objetivos en este campo ya que facilitaría el desarrollo comercial de los vehículos eléctricos impulsados por pilas de combustible. Las membranas híbridas orgánico-inorgánicas nanoestructuradas combinan las propiedades necesarias para este tipo de aplicación. Se obtuvieron membranas híbridas dopadas con ácido fosfowolfrámico (PWA por copolimerización radicálica a partir de alquilalcóxidos y monómeros de estireno y metacrilato, y por reacción sol-gel vía catálisis ácida. La conductividad protónica se logra realizando un proceso

COMBUSTION SIMULATION IN A SPARK IGNITION ENGINE CYLINDER: EFFECTS OF AIR-FUEL RATIO ON THE COMBUSTION DURATION

Directory of Open Access Journals (Sweden)

Nureddin Dinler

2010-01-01

Full Text Available Combustion is an important subject of internal combustion engine studies. To reduce the air pollution from internal combustion engines and to increase the engine performance, it is required to increase combustion efficiency. In this study, effects of air/fuel ratio were investigated numerically. An axisymmetrical internal combustion engine was modeled in order to simulate in-cylinder engine flow and combustion. Two dimensional transient continuity, momentum, turbulence, energy, and combustion equations were solved. The k-e turbulence model was employed. The fuel mass fraction transport equation was used for modeling of the combustion. For this purpose a computational fluid dynamics code was developed by using the finite volume method with FORTRAN programming code. The moving mesh was utilized to simulate the piston motion. The developed code simulates four strokes of engine continuously. In the case of laminar flow combustion, Arrhenius type combustion equations were employed. In the case of turbulent flow combustion, eddy break-up model was employed. Results were given for rich, stoichiometric, and lean mixtures in contour graphs. Contour graphs showed that lean mixture (l = 1.1 has longer combustion duration.

The Evaluation of Solid Wastes Reduction with Combustion System in the Combustion Chamber

International Nuclear Information System (INIS)

Prayitno; Sukosrono

2007-01-01

The evaluation of solid wastes reduction with combustion system is used for weight reduction factor. The evaluation was done design system of combustion chamber furnace and the experiment was done by burning a certain weight of paper, cloth, plastic and rubber in the combustion chamber. The evaluation of paper wastes, the ratio of wastes (paper, cloth, plastic and rubber) against the factor of weight reduction (%) were investigated. The condition was dimension of combustion chamber furnace = 0.6 X 0.9 X 1.20 X 1 m with combustion chamber and gas chamber and reached at the wastes = 2.500 gram, oxygen pressure 0.5 Bar, wastes ratio : paper : cloth : plastic : rubber = 55 : 10 : 30 : 5, the reduction factor = 6.36 %. (author)

Análisis para la implementación de celdas de combustible en el sistema de propulsión del ARC “Arturus”

Directory of Open Access Journals (Sweden)

Ricardo A Lugo Villalba

2018-01-01

Full Text Available La Armada Nacional con el fin de buscar la excelencia en el cumplimiento de su misión constitucional y en concordancia con las nuevas tendencias medioambientales, ha iniciado una incursión dentro del mundo tecnológico buscando soluciones alternativas a la producción energética con el fin de buscar disminuir los impactos al medio ambiente y a los ecosistemas que lo conforman. Hoy en día los sistemas de propulsión basados en combustibles fósiles y motores de combustión interna instalados a bordo de las unidades de la Armada Nacional generan entre otros, dióxido de carbono como resultado del proceso de combustión, contribuyendo con el efecto invernadero, que junto con la producción de contaminación sonora originan daño ambiental y detrimento en la salud humana. Adicionalmente la inestabilidad de los precios del petróleo ha forzado a la Armada Nacional a buscar soluciones energéticas para los sistemas de propulsión. Por los grandes inconvenientes que se están viviendo, y se vivirán en las Unidades a Flote de la Armada Nacional, a causa de los sistemas de propulsión de combustión interna, se plantea como propuesta alternativa la implementación de celdas de combustible que puedan generar la potencia deseada, sin afectar el medio ambiente, ya que no generan humos de exhaustación; y que pueden también contribuir al desarrollo de las operaciones estratégicas y tácticas tanto en buques como en submarinos, aportando mínimas vibraciones durante el funcionamiento de la maquinaria, originando un bajo nivel de ruido.

Análisis para la implementación de celdas de combustible en el sistema de propulsión del ARC “Arturus”

Directory of Open Access Journals (Sweden)

Ricardo A. Lugo Villalba

2017-02-01

Full Text Available La Armada Nacional con el fin de buscar la excelencia en el cumplimiento de su misión constitucional y en concordancia con las nuevas tendencias medioambientales, ha iniciado una incursión dentro del mundo tecnológico buscando soluciones alternativas a la producción energética con el fin de buscar disminuir los impactos al medio ambiente y a los ecosistemas que lo conforman. Hoy en día los sistemas de propulsión basados en combustibles fósiles y motores de combustión interna instalados a bordo de las unidades de la Armada Nacional generan entre otros, dióxido de carbono como resultado del proceso de combustión, contribuyendo con el efecto invernadero, que junto con la producción de contaminación sonora originan daño ambiental y detrimento en la salud humana. Adicionalmente la inestabilidad de los precios del petróleo ha forzado a la Armada Nacional a buscar soluciones energéticas para los sistemas de propulsión. Por los grandes inconvenientes que se están viviendo, y se vivirán en las Unidades a Flote de la Armada Nacional, a causa de los sistemas de propulsión de combustión interna, se plantea como propuesta alternativa la implementación de celdas de combustible que puedan generar la potencia deseada, sin afectar el medio ambiente, ya que no generan humos de exhaustación; y que pueden también contribuir al desarrollo de las operaciones estratégicas y tácticas tanto en buques como en submarinos, aportando mínimas vibraciones durante el funcionamiento de la maquinaria, originando un bajo nivel de ruido.

Dinámica de la humedad de los combustibles y su relación con la ecologíay manejo de fuego, region chaqueña occidental (Argentina) II: follaje y residuos de árboles y arbustos

OpenAIRE

KUNST,C; LEDESMA, R; BRAVO, S.; DEFOSSÉ, G.; GODOY, J.; NAVARRETE, V.

2014-01-01

El fuego es fenómeno frecuente en la región chaqueña argentina. El contenido de agua (CH, %) es un factor que define la inflamabilidad de los combustibles vegetales, y sus cambios en magnitud pueden ser usados para comprender la ecología y régimen del fuego en una región, para planificar su uso como prescripto; o como un indicador de riesgo para su prevención. En este trabajo se evaluó la dinámica de CH a través del tiempo del follaje (combustible vivo), hojarasca y residuos leñosos de distin...

Biofuels combustion.

Science.gov (United States)

Westbrook, Charles K

2013-01-01

This review describes major features of current research in renewable fuels derived from plants and from fatty acids. Recent and ongoing fundamental studies of biofuel molecular structure, oxidation reactions, and biofuel chemical properties are reviewed, in addition to combustion applications of biofuels in the major types of engines in which biofuels are used. Biofuels and their combustion are compared with combustion features of conventional petroleum-based fuels. Two main classes of biofuels are described, those consisting of small, primarily alcohol, fuels (particularly ethanol, n-butanol, and iso-pentanol) that are used primarily to replace or supplement gasoline and those derived from fatty acids and used primarily to replace or supplement conventional diesel fuels. Research efforts on so-called second- and third-generation biofuels are discussed briefly.

Indirect enzyme-linked immunosorbent assay method based on Streptococcus agalactiae rSip-Pgk-FbsA fusion protein for detection of bovine mastitis.

Science.gov (United States)

Bu, Ri-E; Wang, Jin-Liang; Wu, Jin-Hua; Xilin, Gao-Wa; Chen, Jin-Long; Wang, Hua

2017-03-01

The aim of this study was to establish a rapid and accurate method for the detection of the Streptococcus agalactiae antibody (SA-Ab) to determine the presence of the bovine mastitis (BM)-causative pathogen. The multi-subunit fusion protein rSip-Pgk-FbsA was prokaryotically expressed and purified. The triple activities of the membrane surface-associated proteins Sip, phosphoglycerate kinase (Pgk), and fibronectin (FbsA) were used as the diagnostic antigens to establish an indirect enzyme-linked immunosorbent assay (ELISA) method for the detection of SA-Ab in BM. The optimal antigen coating concentration was 2 μg/mL, the optimal serum dilution was 1:160, and the optimal dilution of the enzyme-labeled secondary antibody was 1:6000. The sensitivity, specificity, and repeatability tests showed that the method established in this study had no cross-reaction with antibodies to Streptococcus pyogenes, Escherichia coli, Staphylococcus aureus, and Staphylococcus epidermidis in the sera. The results of the sensitivity test showed that a positive result could be obtained even if the serum dilution reached 1:12,800, indicating the high sensitivity and good repeatability of the method. The positive coincidence rate of this method was 98.6%, which is higher than that of previous tests established with the Sip or Pgk mono-antigen fusion protein, respectively, demonstrating the relatively higher sensitivity of this newly established method. The detection rate for 389 clinical samples was 46.53%. The indirect ELISA method established in this study could provide a more accurate and reliable serological method for the rapid detection of S. agalactiae in cases of BM.

Low emission internal combustion engine

Science.gov (United States)

Karaba, Albert M.

1979-01-01

A low emission, internal combustion compression ignition engine having a cylinder, a piston movable in the cylinder and a pre-combustion chamber communicating with the cylinder near the top thereof and in which low emissions of NO.sub.x are achieved by constructing the pre-combustion chamber to have a volume of between 70% and 85% of the combined pre-chamber and main combustion chamber volume when the piston is at top dead center and by variably controlling the initiation of fuel injection into the pre-combustion chamber.

Alcohol combustion chemistry

KAUST Repository

Sarathy, Mani; Oß wald, Patrick; Hansen, Nils; Kohse-Hö inghaus, Katharina

2014-01-01

. While biofuel production and its use (especially ethanol and biodiesel) in internal combustion engines have been the focus of several recent reviews, a dedicated overview and summary of research on alcohol combustion chemistry is still lacking. Besides

diesel-biogás para generación de electricidad

Directory of Open Access Journals (Sweden)

Iván Darío Bedoya Caro

2007-01-01

Full Text Available En este trabajo se presentan los resultados obtenidos en la caracterización mecánica y ambiental de un motor de encendido por compresión (MEC para generación de electricidad, operando con diesel y en modo dual diesel-biogás. El motor ha sido acoplado a un generador eléctrico y evaluado a un régimen de 1.800 rpm con varios grados de carga, el biogás se ha simulado con una composición típica de 60% metano (CH4 y 40% de dióxido de carbono (CO2. Se han encontrado disminuciones en la eficiencia efectiva al reducir la cantidad de combustible piloto en modo dual, al igual que aumentos considerables en las emisiones de CH4 y monóxido de carbono (CO, la opacidad del humo no varía significativamente en modo dual, pero muestra una reducción drástica al compararla con las medidas para el motor en modo diesel. Los resultados obtenidos confirman la importancia del uso del biogás como alternativa para mecanismos de desarrollo limpio y como aporte a la disminución de la dependencia energética y económica de los combustibles fósiles

Transient flow combustion

Science.gov (United States)

Tacina, R. R.

1984-01-01

Non-steady combustion problems can result from engine sources such as accelerations, decelerations, nozzle adjustments, augmentor ignition, and air perturbations into and out of the compressor. Also non-steady combustion can be generated internally from combustion instability or self-induced oscillations. A premixed-prevaporized combustor would be particularly sensitive to flow transients because of its susceptability to flashback-autoignition and blowout. An experimental program, the Transient Flow Combustion Study is in progress to study the effects of air and fuel flow transients on a premixed-prevaporized combustor. Preliminary tests performed at an inlet air temperature of 600 K, a reference velocity of 30 m/s, and a pressure of 700 kPa. The airflow was reduced to 1/3 of its original value in a 40 ms ramp before flashback occurred. Ramping the airflow up has shown that blowout is more sensitive than flashback to flow transients. Blowout occurred with a 25 percent increase in airflow (at a constant fuel-air ratio) in a 20 ms ramp. Combustion resonance was found at some conditions and may be important in determining the effects of flow transients.

Shale oil combustion

International Nuclear Information System (INIS)

Al-dabbas, M.A.

1992-05-01

A 'coutant' carbon steel combustion chamber cooled by water jacket was conslructed to burn diesel fuel and mixlure of shale oil and diesel fuels. During experimental work nir fuel ratio was determined, temperaturces were measured using Chromel/ Almel thermocouple, finally the gasous combustion product analysis was carricd out using gas chromatograph technique. The constructed combustion chamber was operating salisfactory for several hours of continous work. According to the measurements it was found that: the flame temperature of a mixture of diesel and shale oil fuels was greater than the flame temperature of diesel fuel. and the sulfer emissious of a mixture of diesel and shale oil fuels was higher than that of diesel fuel. Calculation indicated that the dry gas energy loss was very high and the incomplete combustion energy loss very small. (author). 23 refs., 35 figs

Shale oil combustion

Energy Technology Data Exchange (ETDEWEB)

Al-dabbas, M A

1992-05-01

A `coutant` carbon steel combustion chamber cooled by water jacket was conslructed to burn diesel fuel and mixlure of shale oil and diesel fuels. During experimental work nir fuel ratio was determined, temperaturces were measured using Chromel/ Almel thermocouple, finally the gasous combustion product analysis was carricd out using gas chromatograph technique. The constructed combustion chamber was operating salisfactory for several hours of continous work. According to the measurements it was found that: the flame temperature of a mixture of diesel and shale oil fuels was greater than the flame temperature of diesel fuel. and the sulfer emissious of a mixture of diesel and shale oil fuels was higher than that of diesel fuel. Calculation indicated that the dry gas energy loss was very high and the incomplete combustion energy loss very small. (author). 23 refs., 35 figs.

Propuesta de dispositivo para diagnosticar las bombas de alta presión de los grupos electrógenos MTU serie 4000

Directory of Open Access Journals (Sweden)

Elio Rafael Hidalgo-Batista

2015-01-01

Full Text Available Se presenta el diseño de un dispositivo para el diagnóstico de las bombas de alta presión de combustible de motores de co mbustión interna Diesel de los Grupos Electrógenos MTU Br 4 000 16V G81 , los cuales pertenecen a la Unidad Empresarial de Base de Generación Distribuida de la Empresa Eléctrica Holguín, siendo este el primer objetivo del proyecto, el segundo es la elaborac ión de los pasos necesarios para el montaje y la realización del diagnóstico de las bombas en el banco. El dispositivo obtenido del diseño se montará en la bancada de un torno universal y para el mismo se utilizaran planchas de acero al carbono. El mismo p ermitirá diagnosticar fallas tales como: baja presión en el conducto común, salideros de combustible y goteo de combustible. El valor de la presión existente en el conducto común ( Common Rail se conocerá a través del valor del voltaje medido en el sensor.

Investigation of the combustion kinetics and polycyclic aromatic hydrocarbon emissions from polycaprolactone combustion.

Science.gov (United States)

Chien, Y C; Yang, S H

2013-01-01

Polycaprolactone (PCL) is one of the most attractive biodegradable plastics that has been widely used in medicine and agriculture fields. Because of the large increase in biodegradable plastics usage, the production of waste biodegradable plastics will be increasing dramatically, producing a growing environmental problem. Generally, waste PCL is collected along with municipal solid wastes and then incinerated. This study investigates the combustion kinetics and emission factors of 16 US Environmental Protection Agency (EPA) priority polycyclic aromatic hydrocarbons (PAHs) in the PCL combustion. Experimentally, two reactions are involved in the PCL combustion process, possibly resulting in the emission of carbon dioxide, propanal, protonated caprolactone and very small amounts of PAH produced by incomplete combustion. The intermediate products may continuously be oxidized to form CO2. The emission factors for 16 US EPA priority PAHs are n.d. -2.95 microg/g, which are much lower than those of poly lactic acid and other plastics combustion. The conversion of PCL is 100%. Results from this work suggest that combustion is a good choice for the waste PCL disposal.

Dinámica de la humedad de los combustibles y su relación con la ecología y manejo de fuego, region chaqueña occidental (Argentina) II: follaje y residuos de árboles y arbustos

OpenAIRE

Kunst, Carlos Roberto Guillermo; Ledesma, Ramona Ofelia; Bravo, S.; Defossé, Guillermo Emilio; Godoy, J.; Navarrete, V.

2017-01-01

El fuego es fenómeno frecuente en la región chaqueña argentina. El contenido de agua (CH, %) es un factor que define la inflamabilidad de los combustibles vegetales, y sus cambios en magnitud pueden ser usados para comprender la ecología y régimen del fuego en una región, para planificar su uso como prescripto; o como un indicador de riesgo para su prevención. En este trabajo se evaluó la dinámica de CH a través del tiempo del follaje (combustible vivo), hojarasca y residuos leñosos de distin...

Procedimiento para la combustión de un gas en lecho fijo con un sólido oxidado e instalación asociada

OpenAIRE

Abanades García, Juan Carlos; Fernández García, José Ramón

2013-01-01

La presente invención se encuadra dentro del campo de la obtención de energía a partir de gases combustibles incorporando captura de dióxido de carbono para su uso o almacenamiento permanente, y en concreto se refiere a procedimientos cíclicos de combustión de gases con sólidos oxidados (procesos de "chemical looping") en lecho fijo para resolver el problema del control de temperatura en la combustión de combustibles gaseosos en lechos fijos de óxidos metálicos operando a altas presiones, así...

The Multi-User Droplet Combustion Apparatus: the Development and Integration Concept for Droplet Combustion Payloads in the Fluids and Combustion Facility Combustion Integrated Rack

Science.gov (United States)

Myhre, C. A.

2002-01-01

The Multi-user Droplet Combustion Apparatus (MDCA) is a multi-user facility designed to accommodate four different droplet combustion science experiments. The MDCA will conduct experiments using the Combustion Integrated Rack (CIR) of the NASA Glenn Research Center's Fluids and Combustion Facility (FCF). The payload is planned for the International Space Station. The MDCA, in conjunction with the CIR, will allow for cost effective extended access to the microgravity environment, not possible on previous space flights. It is currently in the Engineering Model build phase with a planned flight launch with CIR in 2004. This paper provides an overview of the capabilities and development status of the MDCA. The MDCA contains the hardware and software required to conduct unique droplet combustion experiments in space. It consists of a Chamber Insert Assembly, an Avionics Package, and a multiple array of diagnostics. Its modular approach permits on-orbit changes for accommodating different fuels, fuel flow rates, soot sampling mechanisms, and varying droplet support and translation mechanisms to accommodate multiple investigations. Unique diagnostic measurement capabilities for each investigation are also provided. Additional hardware provided by the CIR facility includes the structural support, a combustion chamber, utilities for the avionics and diagnostic packages, and the fuel mixing capability for PI specific combustion chamber environments. Common diagnostics provided by the CIR will also be utilized by the MDCA. Single combustible fuel droplets of varying sizes, freely deployed or supported by a tether are planned for study using the MDCA. Such research supports how liquid-fuel-droplets ignite, spread, and extinguish under quiescent microgravity conditions. This understanding will help us develop more efficient energy production and propulsion systems on Earth and in space, deal better with combustion generated pollution, and address fire hazards associated with

Large-eddy simulation of ethanol spray combustion using a finite-rate combustion model

Energy Technology Data Exchange (ETDEWEB)

Li, K.; Zhou, L.X. [Tsinghua Univ., Beijing (China). Dept. of Engineering Mechanics; Chan, C.K. [Hong Kong Polytechnic Univ. (China). Dept. of Applied Mathematics

2013-07-01

Large-eddy simulation of spray combustion is under its rapid development, but the combustion models are less validated by detailed experimental data. In this paper, large-eddy simulation of ethanol-air spray combustion was made using an Eulerian-Lagrangian approach, a subgrid-scale kinetic energy stress model, and a finite-rate combustion model. The simulation results are validated in detail by experiments. The LES obtained statistically averaged temperature is in agreement with the experimental results in most regions. The instantaneous LES results show the coherent structures of the shear region near the high-temperature flame zone and the fuel vapor concentration map, indicating the droplets are concentrated in this shear region. The droplet sizes are found to be in the range of 20-100{mu}m. The instantaneous temperature map shows the close interaction between the coherent structures and the combustion reaction.

Impacts of Combustion Conditions and Photochemical Processing on the Light Absorption of Biomass Combustion Aerosol.

Science.gov (United States)

Martinsson, J; Eriksson, A C; Nielsen, I Elbæk; Malmborg, V Berg; Ahlberg, E; Andersen, C; Lindgren, R; Nyström, R; Nordin, E Z; Brune, W H; Svenningsson, B; Swietlicki, E; Boman, C; Pagels, J H

2015-12-15

The aim was to identify relationships between combustion conditions, particle characteristics, and optical properties of fresh and photochemically processed emissions from biomass combustion. The combustion conditions included nominal and high burn rate operation and individual combustion phases from a conventional wood stove. Low temperature pyrolysis upon fuel addition resulted in "tar-ball" type particles dominated by organic aerosol with an absorption Ångström exponent (AAE) of 2.5-2.7 and estimated Brown Carbon contributions of 50-70% to absorption at the climate relevant aethalometer-wavelength (520 nm). High temperature combustion during the intermediate (flaming) phase was dominated by soot agglomerates with AAE 1.0-1.2 and 85-100% of absorption at 520 nm attributed to Black Carbon. Intense photochemical processing of high burn rate flaming combustion emissions in an oxidation flow reactor led to strong formation of Secondary Organic Aerosol, with no or weak absorption. PM1 mass emission factors (mg/kg) of fresh emissions were about an order of magnitude higher for low temperature pyrolysis compared to high temperature combustion. However, emission factors describing the absorption cross section emitted per kg of fuel consumed (m(2)/kg) were of similar magnitude at 520 nm for the diverse combustion conditions investigated in this study. These results provide a link between biomass combustion conditions, emitted particle types, and their optical properties in fresh and processed plumes which can be of value for source apportionment and balanced mitigation of biomass combustion emissions from a climate and health perspective.

Phenol-Formaldehyde Resin-Based Carbons for CO2 Separation at Sub-Atmospheric Pressures

Directory of Open Access Journals (Sweden)

Noelia Álvarez-Gutiérrez

2016-03-01

Full Text Available The challenge of developing effective separation and purification technologies that leave much smaller energy footprints is greater for carbon dioxide (CO2 than for other gases. In addition to its involvement in climate change, CO2 is present as an impurity in biogas and bio-hydrogen (biological production by dark fermentation, in post-combustion processes (flue gas, CO2-N2 and many other gas streams. Selected phenol-formaldehyde resin-based activated carbons prepared in our laboratory have been evaluated under static conditions (adsorption isotherms as potential adsorbents for CO2 separation at sub-atmospheric pressures, i.e., in post-combustion processes or from biogas and bio-hydrogen streams. CO2, H2, N2, and CH4 adsorption isotherms at 25 °C and up to 100 kPa were obtained using a volumetric equipment and were correlated by applying the Sips model. Adsorption equilibrium was then predicted for multicomponent gas mixtures by extending the multicomponent Sips model and the Ideal Adsorbed Solution Theory (IAST in conjunction with the Sips model. The CO2 uptakes of the resin-derived carbons from CO2-CH4, CO2-H2, and CO2-N2 at atmospheric pressure were greater than those of the reference commercial carbon (Calgon BPL. The performance of the resin-derived carbons in terms of equilibrium of adsorption seems therefore relevant to CO2 separation in post-combustion (flue gas, CO2-N2 and in hydrogen fermentation (CO2-H2, CO2-CH4.

Engine combustion network (Ecn) : characterization and comparison of boundary conditions for different combustion vessels

NARCIS (Netherlands)

Meijer, M.; Somers, L.M.T.; Johnson, J.; Naber, J.; Lee, S.Y.; Malbec, L.M.; Bruneaux, G.; Pickett, L.M.; Bardi, M.; Payri, R.; Bazyn, T.

2012-01-01

The Engine Combustion Network (ECN) is a worldwide group of institutions using combustion vessels and/or performing computational fluid dynamics (CFD) simulation, whose aim is to advance the state of spray and combustion knowledge at engine-relevant conditions. A key activity is the use of spray

Optimization of combustion chamber geometry for stoichiometric diesel combustion using a micro genetic algorithm

Energy Technology Data Exchange (ETDEWEB)

Park, Sung Wook

2010-11-15

This paper describes the optimization of combustion chamber geometry and engine operating conditions for stoichiometric diesel combustion, targeting lower gross indicated specific fuel consumption. The KIVA code, coupled with a micro genetic algorithm population of nine for each generation was used. The optimization variables were composed of ten variables related to the combustion chamber geometry and engine operating conditions. In addition, an auto mesh generator was developed for generating various kinds of combustion chambers, such as open-crater, re-entrant, deep, and shallow types. In addition, the computational models were validated against the experimental results for a stoichiometric process in terms of the combustion pressure history and emissions. Through the preset optimization, a 35% improvement in the gross indicated that specific fuel consumption was achieved. In addition, the optimization results showed that the optimum engine operating conditions employed a premixed charge compression ignition combustion regime with early injection and a narrow spray included angle. Furthermore, a higher boost pressure was used to prevent fuel film formation. (author)

Sistema de simulación de escenarios de ciclos avanzados de combustible nuclear en transición = Simulation system for advanced fuel cycle transition scenarios

OpenAIRE

Merino Rodríguez, Iván

2015-01-01

El estudio de los ciclos del combustible nuclear requieren de herramientas computacionales o "códigos" versátiles para dar respuestas al problema multicriterio de evaluar los actuales ciclos o las capacidades de las diferentes estrategias y escenarios con potencial de desarrollo en a nivel nacional, regional o mundial. Por otra parte, la introducción de nuevas tecnologías para reactores y procesos industriales hace que los códigos existentes requieran nuevas capacidades para evaluar la transi...

Fuzzy control for the operation of an electrical energy generation system based on standard fuel cells PEM; Control difuso para la operacion de un sistema de generacion de energia electrica basado en celdas de combustible tipo PEM

Energy Technology Data Exchange (ETDEWEB)

Vazquez R, Miguel; Gutierrez A, Ruben [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico); Rodriguez P, Alejandro [Centro Nacional de Investigacion y Desarrollo Tecnologico (Cenidet), Cuernavaca, Morelos (Mexico)

2005-07-01

Fuel cells, as totally clean power plants, have many applications in the industry in general, in the transport system, in the electricity generation for domestic consumption and in the communication systems, among others. When developing new forms of generation with renewable energy sources, it must be considered that petroleum will stop in being an available power resource. The interest in the study of the fuel cells has been increased in the last years because it is considered a solution to the supply of distributed energy problem. Therefore, already exist research institutions that are developing work on this technology. A generation of electrical energy system based on fuel cells is a nonlinear system where the control of the variables of the process, such as the temperature of the system and the pressurization of the reactants, are an important aspect for its proper operation, since it influences in the water balance and therefore in the global efficiency of the system. [Spanish] Las celdas de combustible, como fuente de energia totalmente limpia, tienen muchas aplicaciones en la industria en general: en el sistema de transporte, en la generacion de electricidad para consumo domestico y en los sistemas de comunicacion, entre otros. Al desarrollar nuevas formas de generacion con fuentes de energia renovables, se debe considerar que el petroleo dejara de ser un recurso energetico disponible. El interes en el estudio de las celdas de combustible se ha incrementado en los ultimos anos debido a que se le considera una solucion al problema de abasto de energia distribuida. Por lo tanto, ya existen instituciones de investigacion que estan desarrollando trabajos sobre esta tecnologia. Un sistema de generacion de energia electrica basado en celdas de combustible es un sistema no lineal en donde el control de las variables del proceso, tales como la temperatura del sistema y la presurizacion de los reactantes, es un aspecto importante para su buen funcionamiento, ya que

Visual inspection system and sipping design for spent fuel at TRIGA MARK III reactor of Mexico

International Nuclear Information System (INIS)

Delfin, A.; Mazon, R.

2002-01-01

In the framework of the Technical Cooperation Regional Project for Latin America RLA/4/018 for the biennium 2001-2002, one of the activities identified is the characterization of spent fuel. Of these activities an important one is not doubt the physical condition of spent fuel because an appropriate identification of the fuel status will prevent problems of fuel leaks, corrosion problems etc. As part of the activities of the project was decided that countries no having visual inspection and sipping systems should be very desirable to have them as a result of this project. The Triga reactor of Mexico does not have both of them, therefore, it was decided the need of having both system. The paper describe first the way we designed and constructed a remote Visual Inspection System and example of how is operated. Along the experience and problems we have had with the system. Also we will present the design of the Sipping system were two option were considered. First to take a sample of water after a convenient period of time passing through a circuit to a multichannel analyzer and to identify leakage by way of measuring Caesium-137. Second, exists the possibility that the Stainless Steel sleeve of the fuel has only very small failures, so it is going to be very difficult to have leakages unless the fuel is hot. Therefore we are evaluating the possibility of using heaters to increase the temperature of the fuel and succeed on detecting leakages. The results - we hope - will be ready to be presented at the meeting. (author)

Dry Sliding Wear Behavior of A356 Alloy/Mg2Sip Functionally Graded in-situ Composites: Effect of Processing Conditions

Directory of Open Access Journals (Sweden)

S.C. Ram

2016-09-01

Full Text Available In present study, the effect of dry sliding wear conditions of A356 alloy/Mg2Sip functionally graded in-situ composites developed by centrifugal casting method has been studied. A pure commercial A356 alloy (Al–7.5Si–0.3Mg was selected to be the matrix of the composites and primary Mg2Sip reinforcing particles were formed by in-situ chemical reaction with an average grain size of 40-47.8 µm. The Al–(Mg2Sip functionally graded metal matrix composites (FGMMC’s were synthesized by centrifugal casting technique with radial geometry, using two different mould rotating speeds ( 1200 and 1600 rpm. The X-ray diffraction (XRD characterization technique was carried out to confirm the in-situ formed Mg2Si particles in composites. Optical microscopy examination was carried out to reveals the grain refinement of Al-rich grains due to in-situ formed Mg2Si particles. Scanning electron microscope (SEM and Energy dispersive X-ray spectroscopy (EDS techniques were carried out to reveal the distribution of phases, morphological characteristics and confirmation of primary Mg2Si particles in the matrix. The sliding wear behavior was studied using a Pin-on-Disc set-up machine with sliding wear parameters: effect of loads (N, effect of sliding distances (m and effect of Mg on wear at room temperature with a high-carbon chromium steel disc (HRC-64 as counter surfaces. A good correlation was evidenced between the dry sliding behaviour of functionally graded in-situ composites and the distribution of Mg2Si reinforcing particles. Beside the above processing conditions, the dominant wear mechanisms of functionally graded in-situ composites have been correlated with the microstructures. The hardness and wear resistance properties of these composites increase with increasing volume percent of reinforced primary Si/Mg2Si particles toward inner zone of cast cylindrical shapes. The objective of this works was to study the tribological characteristics under dry sliding

Multi-stage combustion using nitrogen-enriched air

Science.gov (United States)

Fischer, Larry E.; Anderson, Brian L.

2004-09-14

Multi-stage combustion technology combined with nitrogen-enriched air technology for controlling the combustion temperature and products to extend the maintenance and lifetime cycles of materials in contact with combustion products and to reduce pollutants while maintaining relatively high combustion and thermal cycle efficiencies. The first stage of combustion operates fuel rich where most of the heat of combustion is released by burning it with nitrogen-enriched air. Part of the energy in the combustion gases is used to perform work or to provide heat. The cooled combustion gases are reheated by additional stages of combustion until the last stage is at or near stoichiometric conditions. Additional energy is extracted from each stage to result in relatively high thermal cycle efficiency. The air is enriched with nitrogen using air separation technologies such as diffusion, permeable membrane, absorption, and cryogenics. The combustion method is applicable to many types of combustion equipment, including: boilers, burners, turbines, internal combustion engines, and many types of fuel including hydrogen and carbon-based fuels including methane and coal.

DIAGNOSIS OF FAILURE OF COMBUSTION IN THE COMBUSTION CHAMBER WITH A THERMOVISION EQUIPMENT

Directory of Open Access Journals (Sweden)

S. V. Vorobiev

2014-01-01

Full Text Available The use of thermovision technology to diagnose failure of the combustion flame test tube of the main combustion chamber gas turbine engine is deal with in the article. Join the thermal radiation of the jet of combustion products and the internal elements was carried out using short-wave thermovision system AGA-782 with spectral spectral filters in several ranges from 3.2 to 5.6 microns. Thermovision is mounted on the axis of the flame tube. The output signal was recorded and processed on a computer in real time, allowing monitor the combustion process and the thermal state of the object during the experiment.

High Combustion Research Facility

Data.gov (United States)

Federal Laboratory Consortium — At NETL's High-Pressure Combustion Research Facility in Morgantown, WV, researchers can investigate new high-pressure, high-temperature hydrogen turbine combustion...

Computational Modeling of Turbulent Spray Combustion

NARCIS (Netherlands)

Ma, L.

2016-01-01

The objective of the research presented in this thesis is development and validation of predictive models or modeling approaches of liquid fuel combustion (spray combustion) in hot-diluted environments, known as flameless combustion or MILD combustion. The goal is to combine good physical insight,

Space Station Freedom combustion research

Science.gov (United States)

Faeth, G. M.

1992-01-01

Extended operations in microgravity, on board spacecraft like Space Station Freedom, provide both unusual opportunities and unusual challenges for combustion science. On the one hand, eliminating the intrusion of buoyancy provides a valuable new perspective for fundamental studies of combustion phenomena. On the other hand, however, the absence of buoyancy creates new hazards of fires and explosions that must be understood to assure safe manned space activities. These considerations - and the relevance of combustion science to problems of pollutants, energy utilization, waste incineration, power and propulsion systems, and fire and explosion hazards, among others - provide strong motivation for microgravity combustion research. The intrusion of buoyancy is a greater impediment to fundamental combustion studies than to most other areas of science. Combustion intrinsically heats gases with the resulting buoyant motion at normal gravity either preventing or vastly complicating measurements. Perversely, this limitation is most evident for fundamental laboratory experiments; few practical combustion phenomena are significantly affected by buoyancy. Thus, we have never observed the most fundamental combustion phenomena - laminar premixed and diffusion flames, heterogeneous flames of particles and surfaces, low-speed turbulent flames, etc. - without substantial buoyant disturbances. This precludes rational merging of theory, where buoyancy is of little interest, and experiments, that always are contaminated by buoyancy, which is the traditional path for developing most areas of science. The current microgravity combustion program seeks to rectify this deficiency using both ground-based and space-based facilities, with experiments involving space-based facilities including: laminar premixed flames, soot processes in laminar jet diffusion flames, structure of laminar and turbulent jet diffusion flames, solid surface combustion, one-dimensional smoldering, ignition and flame

Underground treatment of combustible minerals

Energy Technology Data Exchange (ETDEWEB)

Sarapuu, E

1954-10-14

A process is described for treating oil underground, consisting in introducing several electrodes spaced one from the other in a bed of combustibles underground so that they come in electric contact with this bed of combustibles remaining insulated from the ground, and applying to the electrodes a voltage sufficient to produce an electric current across the bed of combustibles, so as to heat it and create an electric connection between the electrodes on traversing the bed of combustibles.

Numerical simulation of combustion and soot under partially premixed combustion of low-octane gasoline

KAUST Repository

An, Yanzhao

2017-09-23

In-cylinder combustion visualization and engine-out soot particle emissions were investigated in an optical diesel engine fueled with low octane gasoline. Single injection strategy with an early injection timing (−30 CAD aTDC) was employed to achieve partially premixed combustion (PPC) condition. A high-speed color camera was used to record the combustion images for 150 cycles. The regulated emission of carbon dioxide, carbon monoxide, nitrogen oxides and soot mass concentration were measured experimentally. Full cycle engine simulations were performed using CONVERGE™ and the simulation results matched with the experimental results. The in-cylinder soot particle evolution was performed by coupling a reduced toluene reference fuel mechanism including the PAHs formation/oxidation reactions with particulate size mimic model. The results showed that PPC presents typical stratified combustion characteristics, which is significantly different from the conventional diesel spray-driven combustion. The in-cylinder temperature and equivalence ratio overlaid with soot-NO formation regime revealed that PPC operating condition under study mostly avoided the main sooting conditions throughout the entire combustion. The evaluation of temperature distribution showed formaldehyde could be regarded as an indicator for low temperature reactions, while hydroxyl group represents the high temperature reactions. Soot evolution happened during the combustion process, hydroxyl radicals promoted the soot oxidation.

Numerical simulation of combustion and soot under partially premixed combustion of low-octane gasoline

KAUST Repository

An, Yanzhao; Jaasim, Mohammed; Vallinayagam, R.; Vedharaj, S.; Im, Hong G.; Johansson, Bengt.

2017-01-01

In-cylinder combustion visualization and engine-out soot particle emissions were investigated in an optical diesel engine fueled with low octane gasoline. Single injection strategy with an early injection timing (−30 CAD aTDC) was employed to achieve partially premixed combustion (PPC) condition. A high-speed color camera was used to record the combustion images for 150 cycles. The regulated emission of carbon dioxide, carbon monoxide, nitrogen oxides and soot mass concentration were measured experimentally. Full cycle engine simulations were performed using CONVERGE™ and the simulation results matched with the experimental results. The in-cylinder soot particle evolution was performed by coupling a reduced toluene reference fuel mechanism including the PAHs formation/oxidation reactions with particulate size mimic model. The results showed that PPC presents typical stratified combustion characteristics, which is significantly different from the conventional diesel spray-driven combustion. The in-cylinder temperature and equivalence ratio overlaid with soot-NO formation regime revealed that PPC operating condition under study mostly avoided the main sooting conditions throughout the entire combustion. The evaluation of temperature distribution showed formaldehyde could be regarded as an indicator for low temperature reactions, while hydroxyl group represents the high temperature reactions. Soot evolution happened during the combustion process, hydroxyl radicals promoted the soot oxidation.

Fuels and Combustion | Transportation Research | NREL

Science.gov (United States)

Fuels and Combustion Fuels and Combustion This is the March 2015 issue of the Transportation and , combustion strategy, and engine design hold the potential to maximize vehicle energy efficiency and performance of low-carbon fuels in internal combustion engines with a whole-systems approach to fuel chemistry

Sandia Combustion Research Program

Energy Technology Data Exchange (ETDEWEB)

Johnston, S.C.; Palmer, R.E.; Montana, C.A. (eds.)

1988-01-01

During the late 1970s, in response to a national energy crisis, Sandia proposed to the US Department of Energy (DOE) a new, ambitious program in combustion research. Shortly thereafter, the Combustion Research Facility (CRF) was established at Sandia's Livermore location. Designated a ''user facility,'' the charter of the CRF was to develop and maintain special-purpose resources to support a nationwide initiative-involving US inventories, industry, and national laboratories--to improve our understanding and control of combustion. This report includes descriptions several research projects which have been simulated by working groups and involve the on-site participation of industry scientists. DOE's Industry Technology Fellowship program, supported through the Office of Energy Research, has been instrumental in the success of some of these joint efforts. The remainder of this report presents results of calendar year 1988, separated thematically into eleven categories. Referred journal articles appearing in print during 1988 and selected other publications are included at the end of Section 11. Our traditional'' research activities--combustion chemistry, reacting flows, diagnostics, engine and coal combustion--have been supplemented by a new effort aimed at understanding combustion-related issues in the management of toxic and hazardous materials.

Ultra-low pollutant emission combustion method and apparatus

International Nuclear Information System (INIS)

Khinkis, M.J.

1992-01-01

This patent describes a method for ultra-low pollutant emission combustion of fossil fuel. It comprises: introducing into a primary combustion chamber a first fuel portion of about 1 percent to about 20 percent of a total fuel to be combusted; introducing primary combustion air into the primary combustion chamber; introducing a first portion of water into the primary combustion chamber, having a first water heat capacity equivalent to a primary combustion air heat capacity of one of a primary combustion air amount of about 10 percent to about 60 percent of the first stoichiometirc requirement for complete combustion of the first fuel portion and an excess primary combustion air amount of about 20 percent to about 150 percent of the first stoichiometric requirement for complete combustion of the first fuel portion; burning the first fuel portion with the primary combustion air in the primary combustion chamber at a temperature abut 2000 degrees F to about 2700 degrees F producing initial combustion products; passing the initial combustion products into a secondary combustion chamber; introducing into the secondary combustion chamber a second fuel portion of about 80 percent to about 99 percent of the total fuel to be combusted; introducing secondary combustion air into the secondary combustion chamber in an amount of about 105 percent to about 130 percent of a second stoichiometric requirement for complete combustion of the second fuel portion; introducing a second portion of water into the secondary combustion chamber; burning the second fuel portion and any remaining fuel in the initial combustion products; passing the final combustion products into a dilution chamber; introducing dilution air into the dilution chamber; discharging the ultra-low pollutant emission vitiated air form the dilution chamber

ANALYSIS OF INTERNAL COMBUSTION ENGINE WITH A NEW CONCEPT OF POROUS MEDIUM COMBUSTION FOR THE FUTURE CLEAN ENGINE

Directory of Open Access Journals (Sweden)

Ashok A Dhale

2010-01-01

Full Text Available At present, the emissions of internal combustion engine can only be improved by catalytic treatments of the exhaust gases. Such treatments, however, result in high costs and relatively low conversion efficiency. This suggests that a new combustion technique should be developed to yield improved primary combustion processes inside the engine with drastically reduced exhaust gas emissions. To fulfill all requirements, Dr. Franz Drust has proposed a new combustion concept to perform homogenous combustion in internal combustion engines. This concept used the porous medium combustion technique and is called "PM-engine". It is shown that the PM combustion technique can be applied to internal combustion engines. Theoretical considerations are presented for internal combustion engines, indicating that an overall improvement in thermal efficiency can be achieved for the PM-engine. This is explained and general performance of the new PM-engines is demonstrated for a single cylinder, water cooled, direct injection diesel engine. Verification of experiments at primary stage is described that were carried out as a part of the present study.

Alcohol combustion chemistry

KAUST Repository

Sarathy, Mani

2014-10-01

Alternative transportation fuels, preferably from renewable sources, include alcohols with up to five or even more carbon atoms. They are considered promising because they can be derived from biological matter via established and new processes. In addition, many of their physical-chemical properties are compatible with the requirements of modern engines, which make them attractive either as replacements for fossil fuels or as fuel additives. Indeed, alcohol fuels have been used since the early years of automobile production, particularly in Brazil, where ethanol has a long history of use as an automobile fuel. Recently, increasing attention has been paid to the use of non-petroleum-based fuels made from biological sources, including alcohols (predominantly ethanol), as important liquid biofuels. Today, the ethanol fuel that is offered in the market is mainly made from sugar cane or corn. Its production as a first-generation biofuel, especially in North America, has been associated with publicly discussed drawbacks, such as reduction in the food supply, need for fertilization, extensive water usage, and other ecological concerns. More environmentally friendly processes are being considered to produce alcohols from inedible plants or plant parts on wasteland. While biofuel production and its use (especially ethanol and biodiesel) in internal combustion engines have been the focus of several recent reviews, a dedicated overview and summary of research on alcohol combustion chemistry is still lacking. Besides ethanol, many linear and branched members of the alcohol family, from methanol to hexanols, have been studied, with a particular emphasis on butanols. These fuels and their combustion properties, including their ignition, flame propagation, and extinction characteristics, their pyrolysis and oxidation reactions, and their potential to produce pollutant emissions have been intensively investigated in dedicated experiments on the laboratory and the engine scale

A General Purpose Connections type CTI Server Based on SIP Protocol and Its Implementation

Science.gov (United States)

Watanabe, Toru; Koizumi, Hisao

In this paper, we propose a general purpose connections type CTI (Computer Telephony Integration) server that provides various CTI services such as voice logging where the CTI server communicates with IP-PBX using the SIP (Session Initiation Protocol), and accumulates voice packets of external line telephone call flowing between an IP telephone for extension and a VoIP gateway connected to outside line networks. The CTI server realizes CTI services such as voice logging, telephone conference, or IVR (interactive voice response) with accumulating and processing voice packets sampled. Furthermore, the CTI server incorporates a web server function which can provide various CTI services such as a Web telephone directory via a Web browser to PCs, cellular telephones or smart-phones in mobile environments.

Estudio comparativo de los Códecs de voz para comunicaciones de Voip utilizando teléfonos inteligentes - caso de estudio Universidad Católica de Cuenca sede Azogues

OpenAIRE

Ortega Ortega, Martín Educardo

2015-01-01

Este trabajo de investigación presenta un estudio comparativo de los códecs de voz para comunicaciones de VoIP en la Universidad Católica de Cuenca Sede Azogues, mediante la aplicación de diferentes escenarios reales de pruebas utilizando teléfonos móviles celulares inteligentes con cuentas SIP registradas en aplicaciones softphones y configuradas con la dirección IP interna del servidor de VoIP cuando la conexión sea a través de la red WLAN interna del campus universitario,...

Indoor combustion and asthma.

Science.gov (United States)

Belanger, Kathleen; Triche, Elizabeth W

2008-08-01

Indoor combustion produces both gases (eg, nitrogen dioxide, carbon monoxide) and particulate matter that may affect the development or exacerbation of asthma. Sources in the home include both heating devices (eg, fireplaces, woodstoves, kerosene heaters, flued [ie, vented] or nonflued gas heaters) and gas stoves for cooking. This article highlights the recent literature examining associations between exposure to indoor combustion and asthma development and severity. Since asthma is a chronic condition affecting both children and adults, both age groups are included in this article. Overall, there is some evidence of an association between exposure to indoor combustion and asthma, particularly asthma symptoms in children. Some sources of combustion such as coal stoves have been more consistently associated with these outcomes than other sources such as woodstoves.

A Survey of the Fuel Cycles Operated in the United Kingdom; Etude d'ensemble sur les cycles de combustible au Royaume-Uni; Obzor toplivnykh tsiklov, ispol'zuemykh v soedinennom korolevstve; Estudio de los ciclos de combustible utilizados en el Reino Unido

Energy Technology Data Exchange (ETDEWEB)

Allday, C. [United Kingdom Atomic Energy Authority, Risley, Warrington, Lancs (United Kingdom)

1963-10-15

'un combustible au plutonium et ses incidences sur le prix de revient et le cycle du combustible. Enfin, il precise la place qu'occupent les reacteurs a l'uranium naturel gaine de magnox et les reacteurs AGR dans le programme britannique d'energie d'origine nucleaire. (author) [Spanish] a) El ciclo uranio natural/Magnox. En el Reino Unido se ha adoptado el reactor de uranio natural moderado con grafito y refrigerado con gas como base del respectivo programa de energia nucleoelectrica. Se explotan desde hace siete afios los reactores de Calder Hall y Chapelcross; ahora han comenzado a funcionar los reactores de Berkeley y Bradwell, de la Central Electricity Generating Board, y hay reactores en construccion o en proyecto en otros siete emplazamientos. El combustible destinado a esos reactores se prepara y elabora en el establecimiento de Springfields de la Atomic Energy Authority y de alli se transporta al reactor para efectuar la carga. Una vez irradiado y descargado, el combustible se lleva al establecimiento de la AEA en Windscale, para separar el uranio y el plutonio de los productos de fision. El autor resena la experiencia en el Reino Unido en materia de calculo y elaboracion de elementos combustibles, explotacion de reactores, transporte de combustible irradiado y regeneracion del mismo. Alude al comportamiento del combustible en un reactor y a los programas de carga y descarga alternada, tema que se desarrolla mas' extensamente en otra memoria. b) Reactores de combustible enriquecido. En el Reino Unido se viene probando un reactor avanzado refrigerado con gas, cuyo prototipo comenzo a desarrollar potencia en 1963. El combustible se elabora con oxido de uranio enriquecido revestido de acero inoxidable y sera regenerado en una seccion especial que se agregara al establecimiento de separacion de combustible Magnox en Windscale. El uranio enriquecido para el reactor avanzado (AGR) se produce en la planta de difusion gaseosa en Capenhurst. En lugar del oxido de uranio

Numerical investigation of biogas flameless combustion

International Nuclear Information System (INIS)

Hosseini, Seyed Ehsan; Bagheri, Ghobad; Wahid, Mazlan Abdul

2014-01-01

Highlights: • Fuel consumption decreases from 3.24 g/s in biogas conventional combustion to 1.07 g/s in flameless mode. • The differences between reactants and products temperature intensifies irreversibility in traditional combustion. • The temperature inside the chamber is uniform in biogas flameless mode and exergy loss decreases in this technique. • Low O 2 concentration in the flameless mode confirms a complete and quick combustion process in flameless regime. - Abstract: The purpose of this investigation is to analyze combustion characteristics of biogas flameless mode based on clean technology development strategies. A three dimensional (3D) computational fluid dynamic (CFD) study has been performed to illustrate various priorities of biogas flameless combustion compared to the conventional mode. The effects of preheated temperature and wall temperature, reaction zone and pollutant formation are observed and the impacts of combustion and turbulence models on numerical results are discussed. Although preheated conventional combustion could be effective in terms of fuel consumption reduction, NO x formation increases. It has been found that biogas is not eligible to be applied in furnace heat up due to its low calorific value (LCV) and it is necessary to utilize a high calorific value fuel to preheat the furnace. The required enthalpy for biogas auto-ignition temperature is supplied by enthalpy of preheated oxidizer. In biogas flameless combustion, the mean temperature of the furnace is lower than traditional combustion throughout the chamber. Compared to the biogas flameless combustion with uniform temperature, very high and fluctuated temperatures are recorded in conventional combustion. Since high entropy generation intensifies irreversibility, exergy loss is higher in biogas conventional combustion compared to the biogas flameless regime. Entropy generation minimization in flameless mode is attributed to the uniform temperature inside the chamber

Materials for High-Temperature Catalytic Combustion

Energy Technology Data Exchange (ETDEWEB)

Ersson, Anders

2003-04-01

Catalytic combustion is an environmentally friendly technique to combust fuels in e.g. gas turbines. Introducing a catalyst into the combustion chamber of a gas turbine allows combustion outside the normal flammability limits. Hence, the adiabatic flame temperature may be lowered below the threshold temperature for thermal NO{sub X} formation while maintaining a stable combustion. However, several challenges are connected to the application of catalytic combustion in gas turbines. The first part of this thesis reviews the use of catalytic combustion in gas turbines. The influence of the fuel has been studied and compared over different catalyst materials. The material section is divided into two parts. The first concerns bimetallic palladium catalysts. These catalysts showed a more stable activity compared to their pure palladium counterparts for methane combustion. This was verified both by using an annular reactor at ambient pressure and a pilot-scale reactor at elevated pressures and flows closely resembling the ones found in a gas turbine combustor. The second part concerns high-temperature materials, which may be used either as active or washcoat materials. A novel group of materials for catalysis, i.e. garnets, has been synthesised and tested in combustion of methane, a low-heating value gas and diesel fuel. The garnets showed some interesting abilities especially for combustion of low-heating value, LHV, gas. Two other materials were also studied, i.e. spinels and hexa aluminates, both showed very promising thermal stability and the substituted hexa aluminates also showed a good catalytic activity. Finally, deactivation of the catalyst materials was studied. In this part the sulphur poisoning of palladium, platinum and the above-mentioned complex metal oxides has been studied for combustion of a LHV gas. Platinum and surprisingly the garnet were least deactivated. Palladium was severely affected for methane combustion while the other washcoat materials were

Pre-Columbian alloys from the royal tombs of Sipán; energy dispersive X-ray fluorescence analysis with a portable equipment.

Science.gov (United States)

Cesareo, R; Calza, C; Dos Anjos, M; Lopes, R T; Bustamante, A; Fabian S, J; Alva, W; Chero Z, L

2010-01-01

On the north coast of present-day Peru flourished approximately between 50 and 700 AD, the Moche civilization. It was an advanced culture and the Moche were sophisticated metalsmiths, so that they are considered as the finest producers of jewels and artefacts of the region. The Moche metalworking ability was impressively demonstrated by the objects discovered by Walter Alva and coworkers in 1987, in the excavations of the "Tumbas Reales de Sipán". About 50 metal objects from these excavations, now at the namesake Museum, in Lambayeque, north of Peru, were analyzed with a portable equipment using energy-dispersive X-ray fluorescence. This portable equipment is mainly composed of a small size X-ray tube and a thermoelectrically cooled X-ray detector. Standard samples of gold and silver alloys were employed for quantitative analysis. It was determined that the analyzed artefacts from the "Tumbas Reales de Sipán" are mainly composed of gold, silver and copper alloys, of gilded copper and of tumbaga, the last being a poor gold alloy enriched at the surface by depletion gilding, i.e. removing copper from the surface. Copyright 2009 Elsevier Ltd. All rights reserved.

Large eddy simulation and combustion instabilities; Simulation des grandes echelles et instabilites de combustion

Energy Technology Data Exchange (ETDEWEB)

Lartigue, G.

2004-11-15

The new european laws on pollutants emission impose more and more constraints to motorists. This is particularly true for gas turbines manufacturers, that must design motors operating with very fuel-lean mixtures. Doing so, pollutants formation is significantly reduced but the problem of combustion stability arises. Actually, combustion regimes that have a large excess of air are naturally more sensitive to combustion instabilities. Numerical predictions of these instabilities is thus a key issue for many industrial involved in energy production. This thesis work tries to show that recent numerical tools are now able to predict these combustion instabilities. Particularly, the Large Eddy Simulation method, when implemented in a compressible CFD code, is able to take into account the main processes involved in combustion instabilities, such as acoustics and flame/vortex interaction. This work describes a new formulation of a Large Eddy Simulation numerical code that enables to take into account very precisely thermodynamics and chemistry, that are essential in combustion phenomena. A validation of this work will be presented in a complex geometry (the PRECCINSTA burner). Our numerical results will be successfully compared with experimental data gathered at DLR Stuttgart (Germany). Moreover, a detailed analysis of the acoustics in this configuration will be presented, as well as its interaction with the combustion. For this acoustics analysis, another CERFACS code has been extensively used, the Helmholtz solver AVSP. (author)

Manifold methods for methane combustion

Energy Technology Data Exchange (ETDEWEB)

Yang, B.; Pope, S.B. [Cornell Univ., Ithaca, NY (United States)

1995-10-01

Great progresses have been made in combustion research, especially, the computation of laminar flames and the probability density function (PDF) method in turbulent combustion. For one-dimensional laminar flames, by considering the transport mechanism, the detailed chemical kinetic mechanism and the interactions between these two basic processes, today it is a routine matter to calculate flame velocities, extinction, ignition, temperature, and species distributions from the governing equations. Results are in good agreement with those obtained for experiments. However, for turbulent combustion, because of the complexities of turbulent flow, chemical reactions, and the interaction between them, in the foreseeable future, it is impossible to calculate the combustion flow field by directly integrating the basic governing equations. So averaging and modeling are necessary in turbulent combustion studies. Averaging, on one hand, simplifies turbulent combustion calculations, on the other hand, it introduces the infamous closure problems, especially the closure problem with chemical reaction terms. Since in PDF calculations of turbulent combustion, the averages of the chemical reaction terms can be calculated, PDF methods overcome the closure problem with the reaction terms. It has been shown that the PDF method is a most promising method to calculate turbulent combustion. PDF methods have been successfully employed to calculate laboratory turbulent flames: they can predict phenomena such as super equilibrium radical levels, and local extinction. Because of these advantages, PDF methods are becoming used increasingly in industry combustor codes.

Development of a Premixed Combustion Capability for Scramjet Combustion Experiments

Science.gov (United States)

Rockwell, Robert D.; Goyne, Christopher P.; Rice, Brian E.; Chelliah, Harsha; McDaniel, James C.; Edwards, Jack R.; Cantu, Luca M. L.; Gallo, Emanuela C. A.; Cutler, Andrew D.; Danehy, Paul M.

2015-01-01

Hypersonic air-breathing engines rely on scramjet combustion processes, which involve high speed, compressible, and highly turbulent flows. The combustion environment and the turbulent flames at the heart of these engines are difficult to simulate and study in the laboratory under well controlled conditions. Typically, wind-tunnel testing is performed that more closely approximates engine testing rather than a careful investigation of the underlying physics that drives the combustion process. The experiments described in this paper, along with companion data sets being developed separately, aim to isolate the chemical kinetic effects from the fuel-air mixing process in a dual-mode scramjet combustion environment. A unique fuel injection approach is taken that produces a nearly uniform fuel-air mixture at the entrance to the combustor. This approach relies on the precombustion shock train upstream of the dual-mode scramjet combustor. A stable ethylene flame anchored on a cavity flameholder with a uniformly mixed combustor inflow has been achieved in these experiments allowing numerous companion studies involving coherent anti-Stokes Raman scattering (CARS), particle image velocimetry (PIV), and planar laser induced fluorescence (PLIF) to be performed.

Construction and evaluation of a fuel cell prototype (proton exchange fuel cell); Construccion y evaluacion de un prototipo de celda a combustible (proton exchange fuel cell)

Energy Technology Data Exchange (ETDEWEB)

Da Silva, L. [Laboratorio de Pesquisa em Energia - LAPEN, Universidade do Vale do Itajai, São Jose, SC (Brasil)] e-mail: luciano.silva@univali.br; Paula, M.M.S.; Fiori, M [Lasicom, Universidade do Extremos Sul Catarinense (UNESC), Criciuma, S.C. (Brasil); Benavides, R. [Centro de Investigacion en Quimica Aplicada (CIQA), Saltillo, Coahuila (Mexico); Santos, V. [Laboratorio de Pesquisa em Energia - LAPEN, Universidade do Vale do Itajai, São Jose, SC (Brasil)

2009-09-15

Because electric energy is a vitally important material for the development of the country, this work is aimed at offering an alternative methodology for the construction and operational demonstration of a PEMFC fuel cell. Recently discovered natural gas reserves can be exploited using modern methods and its use fulfills generation, distribution and low environmental impact priorities. All these factors can be observed with the use of fuel cells, especially when working with reformed natural gas. In addition to its low environmental impact during the generation of this energy, the use of fuel cells reflects a generator source that can be located with the consumer, further reducing problems created by transmission lines, fuel transport, etc. Fuel cells are receiving a great deal of attention from the international community and some models are already commercially available. They are showing excellent possibilities for becoming one of the future technologies to generate electric energy with low environmental impact. [Spanish] En funcion de la necesidad de energia electrica como insumo de vital importancia para el desarrollo del pais, este trabajo pretende ofrecer una metodologia alternativa para la construccion y demostracion operacional de una celda a combustible del tipo PEMFC. La explotacion de las reservas de gas natural descubiertas recientemente puede realizarse a traves de metodos modernos y su uso tiene las prioridades de generacion, distribucion y bajo impacto ambiental. Todos estos aspectos se pueden observar dentro del uso de celdas a combustible, especialmente cuando se trabaja con gas natural reformado. Ademas del factor de bajo impacto ambiental durante la misma generacion de energia, el uso de las celdas a combustible involucra una fuente generadora, que puede colocarse junto al consumidor, reduciendo aun mas los problemas generados por las lineas de transmision, el transporte del combustible, etc. Las celdas a combustible estan recibiendo una gran

Mathematical Modeling in Combustion Science

CERN Document Server

Takeno, Tadao

1988-01-01

An important new area of current research in combustion science is reviewed in the contributions to this volume. The complicated phenomena of combustion, such as chemical reactions, heat and mass transfer, and gaseous flows, have so far been studied predominantly by experiment and by phenomenological approaches. But asymptotic analysis and other recent developments are rapidly changing this situation. The contributions in this volume are devoted to mathematical modeling in three areas: high Mach number combustion, complex chemistry and physics, and flame modeling in small scale turbulent flow combustion.

Molten salt combustion of radioactive wastes

International Nuclear Information System (INIS)

Grantham, L.F.; McKenzie, D.E.; Richards, W.L.; Oldenkamp, R.D.

1976-01-01

The Atomics International Molten Salt Combustion Process reduces the weight and volume of combustible β-γ contaminated transuranic waste by utilizing air in a molten salt medium to combust organic materials, to trap particulates, and to react chemically with any acidic gases produced during combustion. Typically, incomplete combustion products such as hydrocarbons and carbon monoxide are below detection limits (i.e., 3 ) is directly related to the sodium chloride vapor pressure of the melt; >80% of the particulate is sodium chloride. Essentially all metal oxides (combustion ash) are retained in the melt, e.g., >99.9% of the plutonium, >99.6% of the europium, and >99.9% of the ruthenium are retained in the melt. Both bench-scale radioactive and pilot scale (50 kg/hr) nonradioactive combustion tests have been completed with essentially the same results. Design of three combustors for industrial applications are underway

Experimental study of improvement on combustion control of fluidized bed combustion chamber; Ryudosho shokyakuro no nenshosei no kaizen ni tsuite

Energy Technology Data Exchange (ETDEWEB)

Izumiya, T.; Baba, K.; Koshida, H.; Uetani, J.; Furuta, M.

1998-10-29

Nippon Steel Corporation has carried out an experimental study using the Yawata waste incinerator plant in order to improve combustion control of a fluidized bed combustion chamber. For controlling the forming of dioxin, combustion control is very important in addition to conventional methods. In this paper, we report two studies about improvements on combustion control. In the first study, we verified improvement on combustion control by modifying gas flow at the freeboard. The operational results of the experiments were studied using the numerical model of the combustion chamber. The modification of gas flow at freeboard was confirmed to be effective to obtain a compact design of fluidized bed combustion chamber for municipal waste. In the second, study we improved combustion control for sewage combustion with municipal waste. In burning municipal waste and sewage, it is especially required to take combustion control into careful consideration. In this experiment, we developed a new device for supplying sewage for the appropriate controlling combustion, and verified its effectiveness to combustion control and an effective reduction of dioxin. (author)

Catalytic Combustion of Gasified Waste

Energy Technology Data Exchange (ETDEWEB)

Kusar, Henrik

2003-09-01

This thesis concerns catalytic combustion for gas turbine application using a low heating-value (LHV) gas, derived from gasified waste. The main research in catalytic combustion focuses on methane as fuel, but an increasing interest is directed towards catalytic combustion of LHV fuels. This thesis shows that it is possible to catalytically combust a LHV gas and to oxidize fuel-bound nitrogen (NH{sub 3}) directly into N{sub 2} without forming NO{sub x} The first part of the thesis gives a background to the system. It defines waste, shortly describes gasification and more thoroughly catalytic combustion. The second part of the present thesis, paper I, concerns the development and testing of potential catalysts for catalytic combustion of LHV gases. The objective of this work was to investigate the possibility to use a stable metal oxide instead of noble metals as ignition catalyst and at the same time reduce the formation of NO{sub x} In paper II pilot-scale tests were carried out to prove the potential of catalytic combustion using real gasified waste and to compare with the results obtained in laboratory scale using a synthetic gas simulating gasified waste. In paper III, selective catalytic oxidation for decreasing the NO{sub x} formation from fuel-bound nitrogen was examined using two different approaches: fuel-lean and fuel-rich conditions. Finally, the last part of the thesis deals with deactivation of catalysts. The various deactivation processes which may affect high-temperature catalytic combustion are reviewed in paper IV. In paper V the poisoning effect of low amounts of sulfur was studied; various metal oxides as well as supported palladium and platinum catalysts were used as catalysts for combustion of a synthetic gas. In conclusion, with the results obtained in this thesis it would be possible to compose a working catalytic system for gas turbine application using a LHV gas.

Combustion means for solid fuels

Energy Technology Data Exchange (ETDEWEB)

Murase, D.

1987-09-23

A combustion device for solid fuel, suitable for coal, coke, charcoal, coal-dust briquettes etc., comprising:- a base stand with an opening therein, an imperforate heat resistant holding board locatable to close said opening; a combustion chamber standing on the base stand with the holding board forming the base of the combustion chamber; a wiper arm pivoted for horizontal wiping movement over the upper surface of the holding board; an inlet means at a lower edge of said chamber above the base stand, and/or in a surrounding wall of said chamber, whereby combustion air may enter as exhaust gases leave the combustion chamber; an exhaust pipe for the exhaust gases; generally tubular gas-flow heat-exchange ducting putting the combustion chamber and exhaust pipe into communication; and means capable of moving the holding board into and out of the opening for removal of ash or other residue. The invention can be used for a heating system in a house or in a greenhouse or for a boiler.

Combustion of Waste Wood. Second phase of the collaboration project on waste wood combustion

International Nuclear Information System (INIS)

Andersson, Annika; Andersson, Christer; Eriksson, Jan; Hemstroem, Bengt; Jungstedt, Jenny; Kling, Aasa; Bahr, Bo von; Ekvall, Annika; Eskilsson, David; Tullin, Claes; Harnevie, Henrik; Sieurin, Jan; Keihaes, Juha; Mueller, Christian; Berg, Magnus; Wikman, Karin

2003-08-01

Combustion of waste wood has during the last decade increased dramatically and this has resulted in a number of Swedish plants using this fuel, e.g. Handeloe P11 (Norrkoeping) and ldbaecken P3 (Nykoeping), and yet other plants that are under construction (e.g. Nynaeshamn). The experience from these plants are that waste wood combustion results in a number of operational problems. To some extent these problems are different compared with the problems related to combustion of other biofuels but the situation is not directly comparable to waste incinerators. The problems are mainly related to slagging and fouling of heat exchanger surfaces and accelerated corrosion at relatively low temperature compared to the situation for ordinary biofuels. In some cases an increase in the emissions of specific substances can also result in difficulties to fulfil the EC-directive on waste combustion. Within previous projects the main problems related to combustion of waste wood have been identified and to some extent the cause of these problems has been clarified. One result of this reported investigation is a deeper understanding of the actual causes of these problems. However, the most important result is a number of recommendations for different measures on how to achieve disturbance-free combustion of waste wood. These recommendations actually summarises the most important possible solutions on how to achieve a disturbance-free operation and a lower maintenance cost for boilers combusting waste wood and can thereby be regarded as a short summery of the whole project: 1) Improving fuel quality by Improved sorting at the source and Sieving of the fuel -> Reducing the amount of metals and chlorine and Separation of fines and thereby reducing the amount of metals. 2) Combustion modifications by Avoiding reducing conditions at the heat exchanger surfaces -> Minimising slagging, fouling and corrosion. 3) Additives or co-combustion by Addition of sulphur with the fuel; Injection of

Novel approaches in advanced combustion characterization of fuels for advanced pressurized combustion

Energy Technology Data Exchange (ETDEWEB)

Aho, M.; Haemaelaeinen, J. [VTT Energy (Finland); Joutsenoja, T. [Tampere Univ. of Technology (Finland)

1996-12-01

This project is a part of the EU Joule 2 (extension) programme. The objective of the research of Technical Research Centre of Finland (VTT) is to produce experimental results of the effects of pressure and other important parameters on the combustion of pulverized coals and their char derivates. The results can be utilized in modelling of pressurized combustion and in planning pilot-scale reactors. The coals to be studied are Polish hvb coal, French lignite (Gardanne), German anthracite (Niederberg) and German (Goettelbom) hvb coal. The samples are combusted in an electrically heated, pressurized entrained flow reactor (PEFR), where the experimental conditions are controlled with a high precision. The particle size of the fuel can vary between 100 and 300 {mu}m. The studied things are combustion rates, temperatures and sizes of burning single coal and char particles. The latter measurements are performed with a method developed by Tampere University of Technology, Finland. In some of the experiments, mass loss and elemental composition of the char residue are studied in more details as the function of time to find out the combustion mechanism. Combustion rate of pulverized (140-180 {mu}m) Gardanne lignite and Niederberg anthracite were measured and compared with the data obtained earlier with Polish hvb coal at various pressures, gas temperatures, oxygen partial pressures and partial pressures of carbon dioxide in the second working period. In addition, particle temperatures were measured with anthracite. The experimental results were treated with multivariable partial least squares (PLS) method to find regression equation between the measured things and the experimental variables. (author)

Fuel cells applied to transport; Celdas de combustible aplicadas al transporte

Energy Technology Data Exchange (ETDEWEB)

Vargas Gonzalez, Miguel [Comision Nacional para el Ahorro de Energia, Mexico, D.F. (Mexico)

2001-07-01

The future demand of energy as well as the preservation of the environment have generated, in several countries, the necessity of developing alternative means for the most efficient transformation of energy that causes minimum damages to the environment. The fuel cells technology is outlined as one of the alternating means to the traditional forms of transforming the energy for residential use as well as for the automotive vehicles. At present it is in a final stage of demonstration, reason why as of year 2003 the possibility will exist on automobiles and trucks circulating normally. [Spanish] La futura demanda de energeticos asi como la preservacion del medio ambiente ha generado, en varios paises, la necesidad de desarrollar medios alternos para la transformacion mas eficiente de la energia que cause minimos danos al ambiente. La tecnologia de celdas de combustible se perfila como uno de los medios alternos a la forma tradicional de transformar la energia tanto para uso residencial como para los vehiculos automotores. En la actualidad se encuentra en una etapa final de demostracion por lo que posiblemente a partir del ano 2003 se cuente con automoviles y camiones circulando normalmente.

Development of High Efficiency Clean Combustion Engine Designs for Spark-Ignition and Compression-Ignition Internal Combustion Engines

Energy Technology Data Exchange (ETDEWEB)

Marriott, Craig; Gonzalez, Manual; Russell, Durrett

2011-06-30

This report summarizes activities related to the revised STATEMENT OF PROJECT OBJECTIVES (SOPO) dated June 2010 for the Development of High-Efficiency Clean Combustion engine Designs for Spark-Ignition and Compression-Ignition Internal Combustion Engines (COOPERATIVE AGREEMENT NUMBER DE-FC26-05NT42415) project. In both the spark- (SI) and compression-ignition (CI) development activities covered in this program, the goal was to develop potential production-viable internal combustion engine system technologies that both reduce fuel consumption and simultaneously met exhaust emission targets. To be production-viable, engine technologies were also evaluated to determine if they would meet customer expectations of refinement in terms of noise, vibration, performance, driveability, etc. in addition to having an attractive business case and value. Prior to this activity, only proprietary theoretical / laboratory knowledge existed on the combustion technologies explored The research reported here expands and develops this knowledge to determine series-production viability. Significant SI and CI engine development occurred during this program within General Motors, LLC over more than five years. In the SI program, several engines were designed and developed that used both a relatively simple multi-lift valve train system and a Fully Flexible Valve Actuation (FFVA) system to enable a Homogeneous Charge Compression Ignition (HCCI) combustion process. Many technical challenges, which were unknown at the start of this program, were identified and systematically resolved through analysis, test and development. This report documents the challenges and solutions for each SOPO deliverable. As a result of the project activities, the production viability of the developed clean combustion technologies has been determined. At this time, HCCI combustion for SI engines is not considered production-viable for several reasons. HCCI combustion is excessively sensitive to control variables

Plasma igniter for internal-combustion engines

Science.gov (United States)

Breshears, R. R.; Fitzgerald, D. J.

1978-01-01

Hot ionized gas (plasma) ignites air/fuel mixture in internal combustion engines more effectively than spark. Electromagnetic forces propel plasma into combustion zone. Combustion rate is not limited by flame-front speed.

Combustion and co-combustion of biomass in a bubbling fluidized bed boiler

NARCIS (Netherlands)

Khan, A.A.

2007-01-01

This PhD dissertation concerns the study of different aspects of biomass (co)-combustion in small-scale fluidized bed boilers for heat generation. The most renowned gaseous emissions from fluidized bed combustion, namely, CO and NO, are investigated with the help of experimental and theoretical

Dispersions of Oxides in Oxide Matrices as High-Temperature Reactor Fuels; Dispersions d'oxyde dans des matrices d'oxyde, utilisees comme combustibles dans des reacteurs a haute temperature; Dispersiya okisej v okislovykh matritsakh v kachestve topliva dlya vysokotemperaturnogo reaktora; Empleo de dispersiones de oxidos en matrices de oxidos, como combustibles para reactores de elevada temperatura

Energy Technology Data Exchange (ETDEWEB)

Williams, J. [Atomic Energy Research Establishment, Harwell (United Kingdom)

1963-11-15

posibilidad de utilizar dispersiones de PuO{sub 2}, UO2 y ThO{sub 2} en matrices de BeO, Al{sub 2}O{sub 3}, MgO y SIO{sub 2}, desde el punto de vista de la integridad y elaboracion del combustible. Las dos caracteristicas mas importantes en lo que atane a la integridad del combustible son su estabilidad dimensional y su capacidad de retener los productos de fision. La compatibilidad de los componentes del combustible entre si, y entre ellos y el refrigerante, influye en la estabilidad dimensional, pero en este aspecto, las propiedades de los combustibles en forma de oxido son satisfactorias. A la alteracion de las dimensiones del combustible por irradiacion contribuyen los factores siguientes: deterioracion de la matriz por los neutrones y los fragmentos de fision, deteriorizacion de la fase fisionable/fertil por las radiaciones y gases de los productos de fision acumulados. Las tensiones termicas pueden tambien provocar deformaciones. Los conocimientos que se poseen sobre los mecanismos de atenuacion de tensiones son, sin embargo, insuficientes para permitir un estudio teorico razonable del comportamiento de los materiales. Los estudios sobre la liberacion de productos de fision por los oxidos fisionables/fertiles, realizados tanto en condiciones de irradiacion poco intensa como de elevado grado de combustion, han tratado principalmente de los productos gaseosos, en particular del xenon. Los datos que se poseen sobre el desprendimiento de otros productos de fision son muy escasos, lo mismo que los conocimientos sobre el movimiento de los productos de fision en general a traves de los materiales que podrian utilizarse como matrices. De los estudios realizados sobre la permeabilidad de los oxidos puros sinterizados, se deduce que se deberan alcanzar densidades teoricas de 95%, como minimo, o quiza incluso de 98%, paca eliminar la porosidad de dichas matrices. Se han elaborado una serie de procedimientos para preparar las particulas fisionables/fertiles, para revestirlas y para

Development of Non-Metallic Fuel Elements for a High-Temperature Gas-Cooled Reactor; Mise au point d'elements combustibles non metalliques pour un reacteur a haute temperature, refroidi par un gaz; Razrabotka nemetallicheskikh teplovydelyashchikh ehlementov dlya vysokotemperaturnogo reaktora s gazovym okhlazhdeniem; Elementos combustibles no metalicos para un reactor de temperatura elevada refrigerado por gas

Energy Technology Data Exchange (ETDEWEB)

Liebmann, B.; Schafer, L.; Spener, G. [NUKEM, Nuklear-Chemie und -Metallurgie G.m.b.H., Wolfgang bei Hanau, Federal Republic of Germany (Germany)

1963-11-15

destinados al reactor de alta temperatura refrigerado por gas de la Brown-Boveri/Krupp Reaktorbau GmbH, se investigaron y desarrollaron dos conceptos de elemento combustible. El elemento consiste en ambos casos en una esfera de grafito de 6 cm de diametro que encierra una pastilla cilindrica de combustible de unos 20 mm de diametro y 16 mm de altura. La diferencia entre ambos conceptos estriba en el tipo de combustible y en la forma de preparar las esferas de grafito. En el primero, el combustible se prepara mezclando U{sub 3}O{sub 8} y grafito, prensando esta mezcla en pastillas y haciendo que ambos componentes reaccionen en un horno al vacio a 1800{sup o}C. La razon atomica U : C es 1:45. Como este tipo de pastilla combustible no retiene cuantitativamente los productos de fision, fue necesario impregnar la esfera de grafito para hacerla impermeable y mejorar su poder de retencion. De este modo, se lograron permeabilidades del orden de 10{sup -6}cm{sup 2}/s . Con arreglo al segundo concepto, el combustible consiste en una solucion solida de UC en ZrC recubierta de una capa de ZrC. La razon molar UC : ZrC asciende a 1 : 20. La pastilla combustible se preparo del modo siguiente: se mezclaron UO{sub 2}, ZrO{sub 2} y grafito y se prensaron en pastillas que se hicieron reaccionar para obtener los carburos, que a su vez se trituraron en un molino de bolas, para volver a prensarse a 2000{sup o}C. De este modo, se alcanzaron densidades superiores al 95% del valor teorico. La memoria describe en detalle la preparacion y algunas de las propiedades fisicas de las pastillas combustibles. Se espera que este tipo de combustible retenga suficientemente los gases de fision y permita el empleo de esferas de grafito no impregnadas. La memoria examina tambien otras ventajas de esos combustibles. [Russian] V svyazi s rabotami po sovershenstvovaniyu seplovydelyayushchikh ehlementov dlya vysokotemperaturnogo reaktora s gazovym okhlazhdeniem ''Obshchestvom stroitel'stva reaktorov Braun- Boveri

Avaliação de parâmetros de consumo de combustível do Tritrem no transporte de madeira Evaluation of fuel consumption parameters on Tritrem wood transport

Directory of Open Access Journals (Sweden)

Glauco Lima da Silveira

2004-02-01

Full Text Available Analisou-se o efeito dos parâmetros marcha lenta, excesso de rotação do motor para valores superiores a 2.000 rpm, pontos neutros e velocidades superiores a 80 km/h, com o objetivo de monitorar o consumo de combustível de veículos de transporte rodoviário de duas transportadoras de madeira (A e B, com base nas informações obtidas de um computador de bordo instalado no cavalo-mecânico LS 2638 da Mercedes-Benz. A marcha lenta foi responsável pelo maior desperdiço de combustível; as transportadoras A e B consumiram 20.122,33 e 18.321,72 L/mês, respectivamente. Ela induziu a um consumo mensal de combustível na ordem de R$ 19.164,50 (91,32% e R$ 17.449,61 (99,09%, pois, em média, os motores dos veículos funcionaram 24,47 e 25,79% do tempo de operação para as transportadoras A e B, respectivamente. O excesso de rotação do motor dos veículos também induziu ao consumo mensal de combustível de R$ 69,45 (0,33% para a transportadora A e de R$155,62 (0,88% para a transportadora B. O ponto neutro contribuiu com o consumo de combustível em R$ 1.751,73 (8,35% e R$ 4,80 (0,03%, respectivamente, para as transportadoras A e B. Não foi calculado o consumo relativo ao excesso de velocidade, por não serem conhecidos a faixa de potência, a rotação e o consumo específico associado a cada velocidade. A metodologia usada é específica para o motor OM 457 LA, podendo ser adotada em outros estudos, desde que adaptada às especificações dos motores utilizados; a marcha lenta foi responsável pelo maior consumo de combustível no transporte de madeira, seguida do ponto neutro e do excesso de rotação. No transporte de madeira é possível reduzir significativamente o consumo de combustível em relação à marcha lenta, em virtude do elevado tempo de espera (carregamento, descarregamento, filas e paradas obrigatórias. O uso do ponto neutro e o excesso de velocidade não economizam combustível e comprometem a segurança. As rota

Combustion from basics to applications

CERN Document Server

Lackner, Maximilian; Winter, Franz

2013-01-01

Combustion, the process of burning, is defined as a chemical reaction between a combustible reactant (the fuel) and an oxidizing agent (such as air) in order to produce heat and in most cases light while new chemical species (e.g., flue gas components) are formed. This book covers a gap on the market by providing a concise introduction to combustion. Most of the other books currently available are targeted towards the experienced users and contain too many details and/or contain knowledge at a fairly high level. This book provides a brief and clear overview of the combustion basics, suitable f

Combustion of diesel fuel from a toxicological perspective. I. Origin of incomplete combustion products.

Science.gov (United States)

Scheepers, P T; Bos, R P

1992-01-01

Since the use of diesel engines is still increasing, the contribution of their incomplete combustion products to air pollution is becoming ever more important. The presence of irritating and genotoxic substances in both the gas phase and the particulate phase constituents is considered to have significant health implications. The quantity of soot particles and the particle-associated organics emitted from the tail pipe of a diesel-powered vehicle depend primarily on the engine type and combustion conditions but also on fuel properties. The quantity of soot particles in the emissions is determined by the balance between the rate of formation and subsequent oxidation. Organics are absorbed onto carbon cores in the cylinder, in the exhaust system, in the atmosphere and even on the filter during sample collection. Diesel fuel contains polycyclic aromatic hydrocarbons (PAHs) and some alkyl derivatives. Both groups of compounds may survive the combustion process. PAHs are formed by the combustion of crankcase oil or may be resuspended from engine and/or exhaust deposits. The conversion of parent PAHs to oxygenated and nitrated PAHs in the combustion chamber or in the exhaust system is related to the vast amount of excess combustion air that is supplied to the engine and the high combustion temperature. Whether the occurrence of these derivatives is characteristic for the composition of diesel engine exhaust remains to be ascertained. After the emission of the particles, their properties may change because of atmospheric processes such as aging and resuspension. The particle-associated organics may also be subject to (photo)chemical conversions or the components may change during sampling and analysis. Measurement of emissions of incomplete combustion products as determined on a chassis dynamometer provides knowledge of the chemical composition of the particle-associated organics. This knowledge is useful as a basis for a toxicological evaluation of the health hazards of

Internal combustion engine

Science.gov (United States)

Baker, Quentin A.; Mecredy, Henry E.; O'Neal, Glenn B.

1991-01-01

An improved engine is provided that more efficiently consumes difficult fuels such as coal slurries or powdered coal. The engine includes a precombustion chamber having a portion thereof formed by an ignition plug. The precombustion chamber is arranged so that when the piston is proximate the head, the precombustion chamber is sealed from the main cylinder or the main combustion chamber and when the piston is remote from the head, the precombustion chamber and main combustion chamber are in communication. The time for burning of fuel in the precombustion chamber can be regulated by the distance required to move the piston from the top dead center position to the position wherein the precombustion chamber and main combustion chamber are in communication.

Combustion stratification study of partially premixed combustion using Fourier transform analysis of OH* chemiluminescence images

KAUST Repository

Izadi Najafabadi, Mohammad

2017-11-06

A relatively high level of stratification (qualitatively: lack of homogeneity) is one of the main advantages of partially premixed combustion over the homogeneous charge compression ignition concept. Stratification can smooth the heat release rate and improve the controllability of combustion. In order to compare stratification levels of different partially premixed combustion strategies or other combustion concepts, an objective and meaningful definition of “stratification level” is required. Such a definition is currently lacking; qualitative/quantitative definitions in the literature cannot properly distinguish various levels of stratification. The main purpose of this study is to objectively define combustion stratification (not to be confused with fuel stratification) based on high-speed OH* chemiluminescence imaging, which is assumed to provide spatial information regarding heat release. Stratification essentially being equivalent to spatial structure, we base our definition on two-dimensional Fourier transforms of photographs of OH* chemiluminescence. A light-duty optical diesel engine has been used to perform the OH* bandpass imaging on. Four experimental points are evaluated, with injection timings in the homogeneous regime as well as in the stratified partially premixed combustion regime. Two-dimensional Fourier transforms translate these chemiluminescence images into a range of spatial frequencies. The frequency information is used to define combustion stratification, using a novel normalization procedure. The results indicate that this new definition, based on Fourier analysis of OH* bandpass images, overcomes the drawbacks of previous definitions used in the literature and is a promising method to compare the level of combustion stratification between different experiments.

Experimental research on combustion fluorine retention using calcium-based sorbents during coal combustion (II)

Energy Technology Data Exchange (ETDEWEB)

Qi, Q.; Ma, X.; Liu, J.; Wu, X.; Zhou, J.; Cen, K. [Liaoning Technical University, Fuxin (China). College of Resource and Environment Engineering

2008-12-15

Fluoride pollution produced by coal burning can be controlled with the calcium-based sorbent combustion fluorine technique in which calcium-based sorbents are mixed with the coal or sprayed into the combustion chamber. In a fixed bed tube furnace combustion experiment using one calcium-based natural mineral, limestone and one calcium-based building material, it was shown that the calcium-based sorbent particle grain size and pore structure have a big influence on the combustion fluorine retention effect. Reducing the calcium-based sorbent particle grain size and improving the calcium sorbent structure characteristics at very high temperature to enhance the fluorine retention effect is the important approach to the fluorine retention agent development. 8 refs., 1 fig., 5 tabs.

Influência do combustível (diesel e biodiesel e das características da frota de veículos do transporte coletivo de Curitiba, Paraná, nas emissões de NOx

Directory of Open Access Journals (Sweden)

Wellington Ferreira Ribas

Full Text Available RESUMO: O sistema de transporte coletivo da cidade de Curitiba, no Paraná, é reconhecido pelas suas soluções inovadoras e modelo para o Brasil. Neste trabalho foi analisada a influência do combustível (diesel e biodiesel e das condições da frota de veículos do transporte coletivo de Curitiba nas emissões de NOx, e essa é uma iniciativa pioneira. Foram selecionados 188 veículos (9,7% do total com motores de 7 a 12 L, denominados B7R, B10M, B12M e B215RH, e foram realizadas medições de NO e NO2 na saída dos escapamentos. Com relação ao tipo de combustível, as emissões de NO e NO2 para o biodiesel (B100 foram, respectivamente, 37 e 26% superiores aos valores observados com o combustível diesel (S10. Comparando motores B12M com até 3 e 10 anos de operação, as emissões médias de NOx foram próximas de 40% maior. Assim, foi possível observar que os veículos a biodiesel tiveram maior emissão de NOx quando comparados com veículos a diesel, em condições similares de operação e tempo de uso do motor. Entretanto, embora o uso de biodiesel traga vantagens ambientais, como energia renovável, novas tecnologias e dispositivos devem ser desenvolvidos para controlar emissões de NO e NO2 em motores que utilizam esse tipo de combustível. Para trabalhos futuros, os autores recomendam testes em dinamômetro, para simular emissões de NOx em motores a diesel e biodiesel em diferentes condições de carga e regime de rotação do motor.

Balance térmico de hornos de panaderías con el empleo de gas como combustible

Directory of Open Access Journals (Sweden)

Manuel Plá Duporté

2011-03-01

Full Text Available En el trabajo se muestra un método para la evaluación térmica de los hornos criollos de panadería, el cual permite calculartodas las pérdidas de calor, la eficiencia y el consumo específico de combustible. Mediante este método se puedenrealizar ajustes de aquellos factores que provocan un incremento en el consumo de combustible de dichos hornos yanalizar las modificaciones y operaciones necesarias para lograr elevar la eficiencia y que sea factible la sustitución delgasoil por gas manufacturado.La evaluación realizada a estos hornos aporta datos hasta ahora desconocidos por ser esta la primera vez que se realizaun estudio usando gas manufacturado; pues en los realizados anteriormente el combustible empleado ha sido diesel.Se llevó a cabo con la ayuda de un programa de computación en Visual Basic y un programa en Excel que permitieron elanálisis de variantes, para la más adecuada valoración técnico económica que permita la toma de decisiones correctas.  In the work an analysis of the feasibility of the substitution of gas-oil for manufactured gas in the net of bakeries of theCity of Havana is made. It is carried out the energy evaluation of a national oven which uses manufactured gas as fuel.This allowed to obtain the different energy losses that take place in the same one, their efficiency and the specificconsumption of energy.This evaluation is carried out for the first time in a national oven using this type of fuel and it was carried out with thehelp of a calculation program in Visual Basic and a program in Excel that allowed the analysis of variants, all thatwith the goal of obtain the appropriate economic technic valuation that allows the taking of correct decisions.

Observación de la fracción de agua líquida en pilas de combustible tipo PEM de cátodo abierto

OpenAIRE

Luna, Julio; Costa Castelló, Ramón

2017-01-01

En este trabajo se diseña un observador no-lineal basado en modos deslizantes para la estimación de la fracción de agua líquida en una pila de combustible tipo PEM de cátodo abierto. La pila de combustible se modela con dos estados dinámicos: la temperatura de la pila y la saturación de agua líquida. La estrategia de observación se valida en simulación mediante un ciclo de conducción ARTEMIS.

Gestión óptima de la energía en vehículos híbridos basados en pilas de combustible utilizando control predictivo económico

OpenAIRE

Sampietro, Jose Luis; Costa Castelló, Ramon; Puig Cayuela, Vicenç

2016-01-01

Las pilas de combustible que utilizan el hidrégeno como combustible están siendo consideradas, en estos últimos años, como una alternativa a los combustibles fósiles para su uso en automóviles. Dicha tecnología se puede utilizar en los vehículos eléctricos o de propulsión híbrida ya en uso. Este trabajo introduce el control predictivo económico (EMPC, siglas en inglés) como técnica de gestión óptima de la energía. Finalmente, se presentan simulaciones de varios escenarios, basados en un contr...

Prevention of criticality accidents. Fuel elements storage; Prevencion de accidentes de criticidad. Almacenamiento de elementos combustibles

Energy Technology Data Exchange (ETDEWEB)

Canavese, S I; Capadona, N M

1991-12-31

Before the need to store fuel elements of the plate type MTR (Materials Testing Reactors), produced with enriched uranium at 20% in U235 for research reactors, it requires the design of a deposit for this purpose, which will give intrinsic security at a great extent and no complaints regarding its construction, is required. (Author). [Espanol] Partiendo de la necesidad de almacenar elementos combustibles tipo placa MTR (Materials Testing Reactors), producidos con uranio enriquecido al 20% en U235 para reactores de investigacion, se requiere el diseno de un deposito para tal fin que brinde esencialmente un alto grado de seguridad intrinseca y que no ofrezca complicaciones en cuanto a su construccion. (Autor).

Pressurized Fluidized Bed Combustion of Sewage Sludge

Science.gov (United States)

Suzuki, Yoshizo; Nojima, Tomoyuki; Kakuta, Akihiko; Moritomi, Hiroshi

A conceptual design of an energy recovering system from sewage sludge was proposed. This system consists of a pressurized fluidized bed combustor, a gas turbine, and a heat exchanger for preheating of combustion air. Thermal efficiency was estimated roughly as 10-25%. In order to know the combustion characteristics of the sewage sludge under the elevated pressure condition, combustion tests of the dry and wet sewage sludge were carried out by using laboratory scale pressurized fluidized bed combustors. Combustibility of the sewage sludge was good enough and almost complete combustion was achieved in the combustion of the actual wet sludge. CO emission and NOx emission were marvelously low especially during the combustion of wet sewage sludge regardless of high volatile and nitrogen content of the sewage sludge. However, nitrous oxide (N2O) emission was very high. Hence, almost all nitrogen oxides were emitted as the form of N2O. From these combustion tests, we judged combustion of the sewage sludge with the pressurized fluidized bed combustor is suitable, and the conceptual design of the power generation system is available.

AIR EMISSIONS FROM SCRAP TIRE COMBUSTION

Science.gov (United States)

The report discusses air emissions from two types of scrap tire combustion: uncontrolled and controlled. Uncontrolled sources are open tire fires, which produce many unhealthful products of incomplete combustion and release them directly into the atmosphere. Controlled combustion...

Thermogravimetric analysis of biowastes during combustion

International Nuclear Information System (INIS)

Otero, M.; Sanchez, M.E.; Gomez, X.; Moran, A.

2010-01-01

The combustion of sewage sludge (SS), animal manure (AM) and the organic fraction of municipal solid waste (OFMSW) was assessed and compared with that of a semianthracite coal (SC) and of a PET waste by thermogravimetric (TG) analysis. Differences were found in the TG curves obtained for the combustion of these materials accordingly to their respective proximate analysis. Non-isothermal thermogravimetric data were used to assess the kinetics of the combustion of these biowastes. The present paper reports on the application of the Vyazovkin model-free isoconversional method for the evaluation of the activation energy necessary for the combustion of these biowastes. The activation energy related to SS combustion (129.1 kJ/mol) was similar to that corresponding to AM (132.5 kJ/mol) while the OFMSW showed a higher value (159.3 kJ/mol). These values are quite higher than the one determined in the same way for the combustion of SC (49.2 kJ/mol) but lower than that for the combustion of a PET waste (165.6 kJ/mol).

Straw combustion on slow-moving grates

DEFF Research Database (Denmark)

Kær, Søren Knudsen

2005-01-01

Combustion of straw in grate-based boilers is often associated with high emission levels and relatively poor fuel burnout. A numerical grate combustion model was developed to assist in improving the combustion performance of these boilers. The model is based on a one-dimensional ‘‘walking......-column’’ approach and includes the energy equations for both the fuel and the gas accounting for heat transfer between the two phases. The model gives important insight into the combustion process and provides inlet conditions for a computational fluid dynamics analysis of the freeboard. The model predictions...... indicate the existence of two distinct combustion modes. Combustion air temperature and mass flow-rate are the two parameters determining the mode. There is a significant difference in reaction rates (ignition velocity) and temperature levels between the two modes. Model predictions were compared...

Oxy-fuel combustion of solid fuels

DEFF Research Database (Denmark)

Toftegaard, Maja Bøg; Brix, Jacob; Jensen, Peter Arendt

2010-01-01

Oxy-fuel combustion is suggested as one of the possible, promising technologies for capturing CO2 from power plants. The concept of oxy-fuel combustion is removal of nitrogen from the oxidizer to carry out the combustion process in oxygen and, in most concepts, recycled flue gas to lower the flame...... provide additional options for improvement of process economics are however likewise investigated. Of particular interest is the change of the combustion process induced by the exchange of carbon dioxide and water vapor for nitrogen as diluent. This paper reviews the published knowledge on the oxy......-fuel process and focuses particularly on the combustion fundamentals, i.e. flame temperatures and heat transfer, ignition and burnout, emissions, and fly ash characteristics. Knowledge is currently available regarding both an entire oxy-fuel power plant and the combustion fundamentals. However, several...

Combustion Velocity of Benzine-Benzol-Air Mixtures in High-Speed Internal-Combustion Engines

Science.gov (United States)

Schnauffer, Kurt

1932-01-01

The present paper describes a device whereby rapid flame movement within an internal-combustion engine cylinder may be recorded and determined. By the aid of a simple cylindrical contact and an oscillograph the rate of combustion within the cylinder of an airplane engine during its normal operation may be measured for gas intake velocities of from 30 to 35 m/s and for velocities within the cylinder of from 20 to 25 m/s. With it the influence of mixture ratios, of turbulence, of compression ratio and kind of fuel on combustion velocity may be determined. Besides the determination of the influence of the above factors on combustion velocity, the degree of turbulence may also be determined. As a unit of reference in estimating the degree of turbulence, the intake velocity of the charge is chosen.

Use of combustible wastes as fuel

Energy Technology Data Exchange (ETDEWEB)

Kotler, V.R.; Salamov, A.A.

1983-01-01

Achievements of science and technology in creating and using units for combustion of wastes with recovery of heat of the escaping gases has been systematized and generalized. Scales and outlooks are examined for the use of general, industrial and agricultural waste as fuel, composition of the waste, questions of planning and operating units for combustion of solid refuse, settling of waste water and industrial and agricultural waste. Questions are covered for preparing them for combustion use in special units with recovery of heat and at ES, aspects of environmental protection during combustion of waste, cost indicators of the employed methods of recovering the combustible waste.

Combustion characteristics and influential factors of isooctane active-thermal atmosphere combustion assisted by two-stage reaction of n-heptane

Energy Technology Data Exchange (ETDEWEB)

Lu, Xingcai; Ji, Libin; Ma, Junjun; Zhou, Xiaoxin; Huang, Zhen [Key Lab. for Power Machinery and Engineering of MOE, Shanghai Jiao Tong University, 200240 Shanghai (China)

2011-02-15

This paper presents an experimental study on the isooctane active-thermal atmosphere combustion (ATAC) which is assisted by two-stage reaction of n-heptane. The active-thermal atmosphere is created by low- and high-temperature reactions of n-heptane which is injected at intake port, and isooctane is directly injected into combustion chamber near the top dead center. The effects of isooctane injection timing, active-thermal atmosphere intensity, overall equivalence ratio, and premixed ratio on combustion characteristics and emissions are investigated. The experimental results reveal that, the isooctane ignition and combustion can be classified to thermal atmosphere combustion, active atmosphere combustion, and active-thermal atmosphere combustion respectively according to the extent of n-heptane oxidation as well as effects of isooctane quenching and charge cooling. n-Heptane equivalence ratio, isooctane equivalence ratio and isooctane delivery advance angle are major control parameters. In one combustion cycle, the isooctane ignited and burned after those of n-heptane, and then this combustion phenomenon can also be named as dual-fuel sequential combustion (DFSC). The ignition timing of the overall combustion event is mainly determined by n-heptane equivalence ratio and can be controlled in flexibility by simultaneously adjusting isooctane equivalence ratio. The isooctane ignition regime, overall thermal efficiency, and NO{sub x} emissions show strong sensitivity to the fuel delivery advance angle between 20 CA BTDC and 25 CA BTDC. (author)

Simulation of low temperature combustion mechanism of different combustion-supporting agents in close-coupled DOC and DPF system.

Science.gov (United States)

Jiao, Penghao; Li, Zhijun; Li, Qiang; Zhang, Wen; He, Li; Wu, Yue

2018-07-01

In the coupled Diesel Oxidation Catalyst (DOC) and Diesel Particular Filter (DPF) system, soot cannot be completely removed by only using the passive regeneration. And DPF active regeneration is necessary. The research method in this paper is to spray different kinds of combustion-supporting agents to the DOC in the front of the DPF. Therefore, the low temperature combustion mechanism of different kinds of combustion-supporting agents in DOC was studied, in order to grasp the law of combustion in DOC, and the influence of follow-up emission on DPF removal of soot. During the study, CH 4 H 2 mixture and diesel (n-heptane + toluene) were used as combustion-supporting agents respectively. The simplified mechanisms of two kinds of gas mixtures used as the combustion-supporting agents in DPF have been constructed and testified in the paper. In this paper, the combustion and emission conditions of the two combustion-supporting agents were analyzed so as to meet the practical requirements of different working conditions. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

Strobes: An oscillatory combustion

NARCIS (Netherlands)

Corbel, J.M.L.; Lingen, J.N.J. van; Zevenbergen, J.F.; Gijzeman, O.L.J.; Meijerink, A.

2012-01-01

Strobe compositions belong to the class of solid combustions. They are mixtures of powdered ingredients. When ignited, the combustion front evolves in an oscillatory fashion, and flashes of light are produced by intermittence. They have fascinated many scientists since their discovery at the

Fifteenth combustion research conference

International Nuclear Information System (INIS)

1993-01-01

The BES research efforts cover chemical reaction theory, experimental dynamics and spectroscopy, thermodynamics of combustion intermediates, chemical kinetics, reaction mechanisms, combustion diagnostics, and fluid dynamics and chemically reacting flows. 98 papers and abstracts are included. Separate abstracts were prepared for the papers

Numerical analysis for controlling mixture heterogeneity to reduce abrupt combustion in diesel PCCI combustion

Energy Technology Data Exchange (ETDEWEB)

Nishiwaki, Kazuie [Ritsumeikan University (Japan); Kojima, Takafumi [Takamatsu National College of Technology (Japan)

2010-07-01

In the energy sector, stringent regulations have been implemented on combustion emissions in order to address health and environmental concerns and help improve air quality. A novel combustion mode, premixed charge compression ignition (PCCI), can improve the emissions performance of an engine over that of conventional diesel. The aim of this research is to develop a model to analyze the mixture formation in the PCCI combustion mode. A numerical model was developed and was applied to an engine and the results were compared to experimental results. It was found that the model results are in agreement with the experimental results. This paper presented a novel LES computer model and demonstrated that it is efficient in predicting the mixture formation in the PCCI combustion mode.

Design and construction of an electrolyte PEM test; Diseno y construccion de un electrolizador PEM de prueba

Energy Technology Data Exchange (ETDEWEB)

Gonzalez-Huerta, R. G.; Santillan-Aragon, G. [Instituto Politecnico Nacional, Mexico, D.F. (Mexico)]. E-mail: rosgonzalez_h@yahoo.com.mx; Solorza-Feria, O. [CINVESTAV-IPN, Mexico D.F. (Mexico)

2009-09-15

The use of hydrogen as a fuel is directly linked to its efficient and clean production. One of the most promising methods is water electrolysis, which coupled with a renewable energy source prevents the emission of pollutants into the atmosphere. If a proton exchange membrane (PEM) electrolysis is used, a highly pure hydrogen is produced, ready to be used in a fuel battery. Many studies and investigations in this area concentrate on finding different stable and selective electrocatalysts for the cathode reaction (production of hydrogen) and anode reaction (production of oxygen). To conduct these studies, equipment is needed to perform electrochemical studies and determine the stability and performance of different electrocatalysts. This work presents the design and construction of an a PEM electrolysis test to determine the performance of different anode electrocatalysts. Its active area is 4 cm{sup 2}, its structure is graphite and the current distribution mesh is made of stainless steel. Its performance was determined using as electrocatalysts 10% Pt/C E-tek® anodes and a 50%-50%, 25%-75% and 75%-25% combination of RuO{sub 2}-IrO{sub 2}. The authors wish to thank the ICYTDF (PICS08-37) for financial support and IPN (SIP-20090433) and architect Nestor Romero for the electrolysis machining. [Spanish] La utilizacion del hidrogeno como combustible esta ligado directamente a su produccion eficiente y limpia, uno de los metodos mas prometedores es la electrolisis del agua, ya que acoplado con una fuente de energia renovable se evita la emision de contaminantes a la atmosfera. Si se utiliza un electrolizador de membrana de intercambio protonico (Tipo PEM), el hidrogeno que se produce es de alta pureza, listo para ser utilizado en una pila de combustible. Muchos estudios e investigaciones en esta area se concentran en encontrar distintos electrocatalizadores estables y selectivos para la reaccion catodica (produccion de hidrogeno) y anodica (produccion de oxigeno). Para

Modeling and simulating combustion and generation of NOx

International Nuclear Information System (INIS)

Lazaroiu, Gheorghe

2007-01-01

This paper deals with the modeling and simulation of combustion processes and generation of NO x in a combustion chamber and boiler, with supplementary combustion in a gas turbine installation. The fuel burned in the combustion chamber was rich gas with a chemical composition more complex than natural gas. Pitcoal was used in the regenerative boiler. From the resulting combustion products, 17 compounds were retained, including nitrogen and sulphur compounds. Using the developed model, the simulation resulted in excess air for a temperature imposed at the combustion chamber exhaust. These simulations made it possible to determine the concentrations of combustion compounds with a variation in excess combustion. (author)

Multi-zone modelling of PCCI combustion

NARCIS (Netherlands)

Egüz, U.; Somers, L.M.T.; Leermakers, C.A.J.; Goey, de L.P.H.

2011-01-01

Early Direct Injection Premixed Charge Compression Ignition (EDI PCCI) combustion is a promising concept for the diesel combustion. Although EDI PCCI assures very low soot and NO xemission levels, the injection is uncoupled from combustion, which narrows down the operating conditions. The main

Combustor nozzle for a fuel-flexible combustion system

Science.gov (United States)

Haynes, Joel Meier [Niskayuna, NY; Mosbacher, David Matthew [Cohoes, NY; Janssen, Jonathan Sebastian [Troy, NY; Iyer, Venkatraman Ananthakrishnan [Mason, OH

2011-03-22

A combustor nozzle is provided. The combustor nozzle includes a first fuel system configured to introduce a syngas fuel into a combustion chamber to enable lean premixed combustion within the combustion chamber and a second fuel system configured to introduce the syngas fuel, or a hydrocarbon fuel, or diluents, or combinations thereof into the combustion chamber to enable diffusion combustion within the combustion chamber.

Design and construction of a new furnace combustion pilot in IIE; Diseno y construccion de un nuevo horno experimental de combustion en el IIE

Energy Technology Data Exchange (ETDEWEB)

Martinez Flores, Marco Antonio; Tamayo Flores, G. A. [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)]. E-mail: mamf@iie.org.mx; gatamayo@iie.org.mx

2010-11-15

To expand the scope of studies and technological developments in the Laboratory of Combustion of the Thermal Process Management a new experimental furnace with a capacity of 1.5 MWt was designed and built. Spray design studies with real operational evaluation (comparison of emission of Combustion products and thermal behavior) as well as information on the behavior of the NO{sub x} emissions will be produced. An automatic control system using a water cooling jacket provides the cooling of the furnace. The furnace design is modular, consisting of six sections. Currently three trials to its maximum load of operation have been performed. The results show that the global energy balance of the furnace matches the design. The flue gas residence time and temperature also match those at the exit of steam generators of big capacity. [Spanish] Para ampliar las posibilidades de estudios y desarrollos tecnologicos del laboratorio de combustion de la Gerencia de Procesos Termicos, se diseno y construyo un nuevo horno experimental con capacidad maxima de 1.5 MegaWatts termicos (MWt). Este horno permitira realizar estudios de diseno de atomizadores con evaluacion de operacion real (comparacion de emision de productos de combustion y comportamiento termico), asi como ampliar la informacion que se tiene en el comportamiento de la emision de los oxidos de nitrogeno (NO{sub x}) que se producen en el horno. El diseno del horno es modular, compuesto por seis secciones, las cuales se enfrian de forma independiente a traves de un sistema de control automatico, empleando una chaqueta de enfriamiento por la cual circula agua. Actualmente se han realizado tres encendidos hasta alcanzar su carga maxima de operacion, los resultados obtenidos muestran que el balance de energia global del horno experimental es practicamente el de diseno y cumple con las caracteristicas de tiempo de residencia y temperatura de gases a la salida del horno de Generadores de Vapor de gran capacidad.

I-TNT: PHONE NUMBER EXPANSION AND TRANSLATION SYSTEM FOR MANAGING INTERCONNECTIVITY ADDRESSING IN SIP PEERING

Directory of Open Access Journals (Sweden)

A. A. KHUDHER

2015-02-01

Full Text Available Voice over IP (VoIP subscribers is growing vastly in the recent years due to the ever increase in smartphones, 3G, WiFi, etc. This growth leads the VoIP service providers to peer with each other through Session Initiation Protocol (SIP peering for low/free cost of voice communication. Naturally, this growth is not without challenges, especially in phone addressing. This paper proposes an I-TNT (Infrastructure-Phone Number Translation numbering system to expand the range of the existing E.164 numbers and mapping between private and public number at the edge of the signalling path. As a result, I-TNT numbering system is successfully implemented and able to allocate the expanded phone numbers to end-users in one service provider.

Establishment of Combustion Model for Isooctane HCCI Marine Diesel Engine and Research on the Combustion Characteristic

Directory of Open Access Journals (Sweden)

Li Biao

2016-01-01

Full Text Available The homogeneous charge compression ignition (HCCI combustion mode applied in marine diesel engine is expected to be one of alternative technologies to decrease nitrogen oxide (NOX emission and improve energy utilization rate. Applying the chemical-looping combustion (CLC mechanism inside the cylinder, a numerical study on the HCCI combustion process is performed taking a marine diesel engine as application object. The characteristic feature of combustion process is displayed. On this basis, the formation and emission of NOX are analyzed and discussed. The results indicate that the HCCI combustion mode always exhibit two combustion releasing heats: low-temperature reaction and high-temperature reaction. The combustion phase is divided into low-temperature reaction zone, high-temperature reaction zone and negative temperature coefficient (NTC zone. The operating conditions of the high compression ratio, high intake air temperature, low inlet pressure and small excess air coefficient would cause the high in-cylinder pressure which often leads engine detonation. The low compression ratio, low intake air temperature and big excess air coefficient would cause the low combustor temperature which is conducive to reduce NOX emissions. These technological means and operating conditions are expected to meet the NOX emissions limits in MARPOL73/78 Convention-Annex VI Amendment.

Application of RNA Stable Isotope Probing (SIP) to Link Community Activity with Microorganisms Responsible for Autotrophy in the Subseafloor at Axial Seamount

Science.gov (United States)

Huber, J. A.; Fortunato, C. S.

2014-12-01

The global ocean comprises the Earth's largest biome, with microorganisms playing a dominant biogeochemical role. However, the potential for production of new microbial biomass within the subseafloor is rarely considered in traditional oceanographic paradigms of carbon cycling or microbial food webs. In this study, we used RNA Stable Isotope Probing (RNA SIP) to determine the microbial community composition and genetic repertoire of active subseafloor autotrophs in warm venting fluids from Axial Seamount. RNA is a responsive biomarker because it is a reflection of cellular activity independent of replication, and RNA SIP thus provides access to both the function of a microbial community and the phylogeny of the organisms accountable for key functions. Diffuse fluids were incubated shipboard at 30°C, 55°C, and 80°C with 13DIC and H2. Metatranscriptomic sequencing of both the enriched and non-enriched RNA was carried out from 13C and 12C controls. In addition, filtered fluid samples were preserved in situ for comparative meta -transcriptomic and -genomic analyses. Diverse lineages of bacteria and archaea and accompanying metabolisms were detected in situ, but RNA SIP results show dominance of three different groups of autotrophs active under each experimental condition. At 30°C, members of the Sulfurimonas genus dominated, with genes for hydrogen oxidation, nitrate reduction, and carbon fixation via the rTCA cycle highly expressed. At 55°C, both Caminibacter and Nautilia transcripts were detected for rTCA cycle, hydrogen oxidation, and nitrate reduction. At 80°C, transcripts for hydrogenotrophic methanogenesis mediated by members of Methanocaldococcus were detected. These results suggest the subseafloor hosts various anaerobic chemolithoautotrophs that span a wide temperature range, with hydrogen playing a key role in microbial metabolism. Complementary experiments are currently being carried out on the seafloor with a novel in situ incubator unit to provide

Emission and combustion characteristics of multiple stage diesel combustion; Nidan nensho ni yoru diesel kikan no nensho to haishutsubutsu tokusei

Energy Technology Data Exchange (ETDEWEB)

Hashizume, T; Miyamoto, T; Tsujimura, K [New A.C.E. Institute Co. Ltd., Tokyo (Japan); Kobayashi, S; Shimizu, K [Japan Automobile Research Institute, Tsukuba (Japan)

1997-10-01

A new concept of multiple stage diesel combustion was studied by means of engine test, combustion observation and numerical simulation, in order to reduce NOx emissions at high load conditions. With this concept, the premixed combustion occurs under the fuel lean conditions and the diffusion combustion occurs under the high temperature conditions. As seen in the result of combustion observation, a first stage combustion occurs with no luminous flame. A second stage combustion occurs with a luminous flame after very short ignition delay period. However the luminous flame is disappeared immediately. Because cylinder temperature is high, and hence soot oxidizes immediately. 5 refs., 11 figs., 1 tab.

Comportamento de barreiras minerais com solo compactado na faixa granulométrica ótima para contenção de líquidos orgânicos

OpenAIRE

Carvalho, Zenite da Silva

2015-01-01

Este trabalho de pesquisa sobre permeabilidade de líquidos orgânicos em solos compactados, para avaliar o comportamento da proposição de faixa granulométrica de solo com potencial de uso como barreiras de contenção de produtos combustíveis. A justificativa para esta pesquisa está no fato que uma das principais fontes de contaminação de solos e águas subterrâneas têm sido os vazamentos de tanques de armazenamento de combustíveis derivados de petróleo. A contaminação do solo pode gerar danos à ...

Propriedades físico-químicas relacionadas ao desenvolvimento de membranas de Nafion® para aplicações em células a combustível do tipo PEMFC Physicochemical properties related to the development of Nafion® membranes for application in fuel cells

Directory of Open Access Journals (Sweden)

Carlos E. Perles

2008-01-01

Full Text Available Embora não seja tecnologia recente, as células a combustível ou Fuel Cells (FC continuam recebendo grande atenção, pois são consideradas como "fontes de energia do futuro" devido a características como alto rendimento energético e baixa emissão de poluentes, permitindo a extensão o tempo de vida das reservas fósseis e contribuindo para a melhoria da qualidade de vida. Atualmente, as pesquisas estão direcionadas, principalmente, ao desenvolvimento de FC para aplicações em sistemas móveis e portáteis. De todas as tecnologias existentes, a mais promissora para essa finalidade é a célula a combustível de eletrólito polimérico, conhecida como PEMFC (Polymer Electrolyte Fuel Cell cuja pesquisa encontra-se focada, principalmente, no desenvolvimento de membranas poliméricas, com o objetivo de reduzir os custos de produção. Este trabalho será focado nos aspectos físico-químicos do desenvolvimento de membranas poliméricas. Serão discutidos aspectos estruturais do Nafion® relacionado-os as seguintes propriedades físico-químicas: fluxo eletrosmótico, permeabilidade gasosa, transporte de água através da membrana, estabilidade química e térmica. Toda a discussão será realizada para polímeros perfluorados, utilizando o Nafion® como modelo representante dessa classe de polímeros.Fuel Cells (FC continue to receive growing attention, in spite of not being a new technology, for they are considered as the "energy source of the future" owing to characteristics such as high energetic yield and low emission of pollutants. FC technology may lead to a reduction in the negative impact from energy sources on the enviroment, thus improving the quality of life and extending the lifetime of fossil combustible reserves. The mainstream of research in FC is now directed at mobile, portable systems, for which the most promising technology is the Polymer Electrolyte Fuel Cells, also known as PEMFC (Polymer Electrolyte Fuel Cell. Research

76 FR 16646 - Circadian, Inc., Clean Energy Combustion, Inc. (n/k/a Clean Energy Combustion Systems, Inc...

Science.gov (United States)

2011-03-24

... SECURITIES AND EXCHANGE COMMISSION [File No. 500-1] Circadian, Inc., Clean Energy Combustion, Inc. (n/k/a Clean Energy Combustion Systems, Inc.), Collectible Concepts Group, Inc., Communitronics of... is a lack of current and accurate information concerning the securities of Clean Energy Combustion...

Predicción y análisis de emisiones de mezclas combustibles diésel/ biodiésel modificadas con nanopartículas de alúmina y ácido oleico

Directory of Open Access Journals (Sweden)

Andrés Peñaloza

2017-06-01

Full Text Available El software Diésel-RK fue utilizado para evaluar el efecto del uso de un aditivo basado en nanopartículas de alúmina y ácido oleico para la reducción de emisiones de gases contaminantes en mezclas diésel/biodiésel. Para esto, se estimaron las propiedades físico-químicas de las mezclas combustibles con ayuda de correlaciones para dispersiones coloidales y reglas de mezclado, fijando concentraciones de 10 y 20ppm del aditivo. Los resultados obtenidos mostraron reducciones del 11% y 25% en emisiones de SO2 y material particulado, respectivamente; mientras que las emisiones de CO2 no mostraron mejoras significativas, así como tampoco se presentaron mejoras en el consumo específico de combustible, los cuales permanecieron por debajo del 1,0%. En cuanto a las emisiones de NO2, se observó un incremento desde 2,1g/kWh a 3,1g/kWh con la adición de las diversas concentraciones de nanoaditivo; de esta forma se evidenciaron mejoras en la disminución en el retraso de los tiempos de ignición, lo cual es apropiado para el adecuado funcionamiento de los motores.

Effect of combustion characteristics on wall radiative heat flux in a 100 MWe oxy-coal combustion plant

Energy Technology Data Exchange (ETDEWEB)

Park, S.; Ryu, C. [Sungkyunkwan Univ., Suwon (Korea, Republic of). School of Mechanical Engineering; Chae, T.Y. [Sungkyunkwan Univ., Suwon (Korea, Republic of). School of Mechanical Engineering; Korea Institute of Industrial Technology, Cheonan (Korea, Republic of). Energy System R and D Group; Yang, W. [Korea Institute of Industrial Technology, Cheonan (Korea, Republic of). Energy System R and D Group; Kim, Y.; Lee, S.; Seo, S. [Korea Electric Power Research Institute (KEPRI), Daejeon (Korea, Republic of). Power Generation Lab.

2013-07-01

Oxy-coal combustion exhibits different reaction, flow and heat transfer characteristics from air-coal combustion due to different properties of oxidizer and flue gas composition. This study investigated the wall radiative heat flux (WRHF) of air- and oxy-coal combustion in a simple hexahedral furnace and in a 100 MWe single-wall-fired boiler using computational modeling. The hexahedral furnace had similar operation conditions with the boiler, but the coal combustion was ignored by prescribing the gas properties after complete combustion at the inlet. The concentrations of O{sub 2} in the oxidizers ranging between 26 and 30% and different flue gas recirculation (FGR) methods were considered in the furnace. In the hexahedral furnace, the oxy-coal case with 28% of O{sub 2} and wet FGR had a similar value of T{sub af} with the air-coal combustion case, but its WRHF was 12% higher. The mixed FGR case with about 27% O{sub 2} in the oxidizer exhibited the WRHF similar to the air-coal case. During the actual combustion in the 100 MWe boiler using mixed FGR, the reduced volumetric flow rates in the oxy-coal cases lowered the swirl strength of the burners. This stretched the flames and moved the high temperature region farther to the downstream. Due to this reason, the case with 30% O{sub 2} in the oxidizers achieved a WRHF close to that of air-coal combustion, although its adiabatic flame temperature (T{sub af}) and WHRF predicted in the simplified hexahedral furnace was 103 K and 10% higher, respectively. Therefore, the combustion characteristics and temperature distribution significantly influences the WRHF, which should be assessed to determine the ideal operating conditions of oxy- coal combustion. The choice of the weighted sum of gray gases model (WSGGM) was not critical in the large coal-fired boiler.

Infrared monitoring of combustion

International Nuclear Information System (INIS)

Bates, S.C.; Morrison, P.W. Jr.; Solomon, P.R.

1991-01-01

In this paper, the use of Fourier Transform Infrared (FT-IR) spectroscopy for combustion monitoring is described. A combination of emission, transmission, and reflection FT-IR spectroscopy yields data on the temperature and composition of the gases, surfaces and suspended particles in the combustion environment. Detection sensitivity of such trace exhaust gases as CO, CO 2 , SO 2 , NO x , and unburned hydrocarbons is at the ppm level. Tomographic reconstruction converts line-of-sight measurements into spatially resolved temperature and concentration data. Examples from various combustion processes are used to demonstrate the capabilities of the technique. Industrial measurements are described that have been performed directly in the combustion zone and in the exhaust duct of a large chemical recovery boiler. Other measurements of hot slag show how FT-IR spectroscopy can determine the temperature and optical properties of surfaces. In addition, experiments with water droplets show that transmission FT-IR data yield spectra that characterize particle size and number density

Avaliação das emissões gasosas de diferentes tipos de combustíveis utilizados e seus impactos ambientais

Directory of Open Access Journals (Sweden)

Waldir Nagel Schirmer

2009-01-01

Full Text Available Este trabalho tem o objetivo de traçar uma revisão sobre os combustíveis utilizados em diferentes processos industriais,com ênfase nos principais gases daí emitidos. A poluição do ar causada por tais poluentes exerce grande influência na saúdehumana e em vários ecossistemas, pois diariamente são liberados altas taxas dos mesmos para a atmosfera. Há alguns anos jáocorrem discussões para que haja a minimização dos problemas ambientais, os acordos internacionais estão sendo fundamentaisnesse contexto uma vez que, entre metas bem definidas, encontram-se a substituição de combustíveis altamente poluidores. Asfontes alternativas de energia têm sido a escolha utilizada pelos países, que além de ambientalmente corretos, possibilitambenefícios para as indústrias.Abstract This work reviews the main fuels used inindustrial processes, emphasizing the gases from theseemissions. The air pollution caused by these pollutants has adirect impact over the human health and ecosystems, due toliberation of these gases to the atmosphere at high rates. Forseveral years, discussions about this theme deal theminimization of the environmental problems andinternational agreements have been done focusing onsubstitution of conventional fuels for another ones. Thealternative energy resources has been chosen by theirbenefits.

Control device for combustible gas concentration

International Nuclear Information System (INIS)

Osawa, Yasuo.

1988-01-01

Purpose: To control the concentration of combustible gases such as hydrogen evolved in a reactor container upon loss-of-coolant accidents. Constitution: Combustible gases evolved from the lower area of a drywell in which a combustible atmosphere is liable to be formed locally are taken out through a take-out pipeway to the outside of a reactor container and processed by a hydrogen-oxygen recombiner. Combustible gases in other areas of the drywell are also introduced to the lower area of the drywell and then taken-out externally for procession. Further, combustible gases in the suppression chamber are introduced by the opening of a vacuum breaking valve through a gas supply pipe to the lower area of the drywell and fluids in the drywell are stirred and diluted with fluids exhausted from the gas supply pipe. Disposition of such take-out pipeway and gas supply pipe can reduce the possibility of forming local combustible atmosphere to improve the integrity of the reactor container. (Kamimura, M.)

Techniques de combustion Combustin Techniques

Directory of Open Access Journals (Sweden)

Perthuis E.

2006-11-01

Full Text Available L'efficacité d'un processus de chauffage par flamme est étroitement liée à la maîtrise des techniques de combustion. Le brûleur, organe essentiel de l'équipement de chauffe, doit d'une part assurer une combustion complète pour utiliser au mieux l'énergie potentielle du combustible et, d'autre part, provoquer dans le foyer les conditions aérodynamiques les plus propices oux transferts de chaleur. En s'appuyant sur les études expérimentales effectuées à la Fondation de Recherches Internationales sur les Flammes (FRIF, au Groupe d'Étude des Flammes de Gaz Naturel (GEFGN et à l'Institut Français du Pétrole (IFP et sur des réalisations industrielles, on présente les propriétés essentielles des flammes de diffusion aux combustibles liquides et gazeux obtenues avec ou sans mise en rotation des fluides, et leurs répercussions sur les transferts thermiques. La recherche des températures de combustion élevées conduit à envisager la marche à excès d'air réduit, le réchauffage de l'air ou son enrichissement à l'oxygène. Par quelques exemples, on évoque l'influence de ces paramètres d'exploitation sur l'économie possible en combustible. The efficiency of a flame heating process is closely linked ta the mastery of, combustion techniques. The burner, an essential element in any heating equipment, must provide complete combustion sa as to make optimum use of the potential energy in the fuel while, at the same time, creating the most suitable conditions for heat transfers in the combustion chamber. On the basis of experimental research performed by FRIF, GEFGN and IFP and of industrial achievements, this article describesthe essential properties of diffusion flames fed by liquid and gaseous fuels and produced with or without fluid swirling, and the effects of such flames on heat transfers. The search for high combustion temperatures means that consideration must be given to operating with reduced excess air, heating the air or

PDF Modeling of Turbulent Combustion

National Research Council Canada - National Science Library

Pope, Stephen B

2006-01-01

.... The PDF approach to turbulent combustion has the advantages of fully representing the turbulent fluctuations of species and temperature, and of allowing realistic combustion chemistry to be implemented...

Sulfur Chemistry in Combustion I

DEFF Research Database (Denmark)

Johnsson, Jan Erik; Glarborg, Peter

2000-01-01

of the sulphur compounds in fossil fuels and the possibilities to remove them will be given. Then the combustion of sulphur species and their influence on the combustion chemistry and especially on the CO oxidation and the NOx formation will be described. Finally the in-situ removal of sulphur in the combustion...... process by reaction between SO2 and calcium containing sorbents and the influence on the NOx chemistry will be treated....

Posibilidad de aprovechamiento de residuos textiles para la obtención de etanol

OpenAIRE

Zurima Menéndez-Ramírez; Azam Jeihanipour; Mohammad Taherzadeh; Lourdes Zumalacárregui-de Cárdenas

2010-01-01

El uso del bioetanol como combustible es una alternativa para minimizar los efectos negativos al medioambiente, ya que reduce el efecto invernadero. En este trabajo se estudian residuos textiles como candidatos para la producción de etanol. Los residuos textiles pretratados con NaOH 12 % (p/v) 0 °C, 3 h (TEP) y sin pretratar (TESP y TDSP), fueron sometidos a procesos simultáneos de sacarificación y fermentación (37 °C, 145 r/min, pH 4,8 a 5). Durante la sacarificación y fermentación, la veloc...

In situ high-temperature gas sensors: continuous monitoring of the combustion quality of different wood combustion systems and optimization of combustion process

Directory of Open Access Journals (Sweden)

H. Kohler

2018-03-01

Full Text Available The sensing characteristics and long-term stability of different kinds of CO ∕ HC gas sensors (non-Nernstian mixed potential type during in situ operation in flue gas from different types of low-power combustion systems (wood-log- and wood-chip-fuelled were investigated. The sensors showed representative but individual sensing behaviour with respect to characteristically varying flue gas composition over the combustion process. The long-term sensor signal stability evaluated by repeated exposure to CO ∕ H2 ∕ N2 ∕ synthetic air mixtures showed no sensitivity loss after operation in the flue gas. Particularly for one of the sensors (Heraeus GmbH, this high signal stability was observed in a field test experiment even during continuous operation in the flue gas of the wood-chip firing system over 4 months. Furthermore, it was experimentally shown that the signals of these CO ∕ HC sensing elements yield important additional information about the wood combustion process. This was demonstrated by the adaptation of an advanced combustion airstream control algorithm on a wood-log-fed fireplace and by the development of a combustion quality monitoring system for wood-chip-fed central heaters.

Internal and surface phenomena in metal combustion

Science.gov (United States)

Dreizin, Edward L.; Molodetsky, Irina E.; Law, Chung K.

1995-01-01

Combustion of metals has been widely studied in the past, primarily because of their high oxidation enthalpies. A general understanding of metal combustion has been developed based on the recognition of the existence of both vapor-phase and surface reactions and involvement of the reaction products in the ensuing heterogeneous combustion. However, distinct features often observed in metal particle combustion, such as brightness oscillations and jumps (spearpoints), disruptive burning, and non-symmetric flames are not currently understood. Recent metal combustion experiments using uniform high-temperature metal droplets produced by a novel micro-arc technique have indicated that oxygen dissolves in the interior of burning particles of certain metals and that the subsequent transformations of the metal-oxygen solutions into stoichiometric oxides are accompanied with sufficient heat release to cause observed brightness and temperature jumps. Similar oxygen dissolution has been observed in recent experiments on bulk iron combustion but has not been associated with such dramatic effects. This research addresses heterogeneous metal droplet combustion, specifically focusing on oxygen penetration into the burning metal droplets, and its influence on the metal combustion rate, temperature history, and disruptive burning. A unique feature of the experimental approach is the combination of the microgravity environment with a novel micro-arc Generator of Monodispersed Metal Droplets (GEMMED), ensuring repeatable formation and ignition of uniform metal droplets with controllable initial temperature and velocity. The droplet initial temperatures can be adjusted within a wide range from just above the metal melting point, which provides means to ignite droplets instantly upon entering an oxygen containing environment. Initial droplet velocity will be set equal to zero allowing one to organize metal combustion microgravity experiments in a fashion similar to usual microgravity

Second law comparison of oxy-fuel combustion and post-combustion carbon dioxide separation

International Nuclear Information System (INIS)

Simpson, Adam P.; Simon, A.J.

2007-01-01

To define 2nd law efficiency targets for novel separation technologies, a simplified model of a power plant with two forms of CO 2 capture was developed. In this investigation, oxy-fuel combustion and post-combustion CO 2 separation were compared on an exergetic basis. Using exergy balances and black-box models of power plant components, multiple scenarios were run to determine the impact of plant configuration and separation unit efficiency on overall plant performance. Second law efficiency values from the literature were used to set the baseline performance of various CO 2 separation configurations. Assumed advances in 2nd law efficiency were used to determine the potential for overall system performance improvement. It was found that the 2nd law efficiency of air separation must reach a critical value before the thermodynamics of oxy-fuel combustion become favorable. Changes in operating equivalence ratio significantly move the tipping-point between post-combustion and oxy-fuel strategies

Investigating co-combustion characteristics of bamboo and wood.

Science.gov (United States)

Liang, Fang; Wang, Ruijuan; Jiang, Changle; Yang, Xiaomeng; Zhang, Tao; Hu, Wanhe; Mi, Bingbing; Liu, Zhijia

2017-11-01

To investigate co-combustion characteristics of bamboo and wood, moso bamboo and masson pine were torrefied and mixed with different blend ratios. The combustion process was examined by thermogravimetric analyzer (TGA). The results showed the combustion process of samples included volatile emission and oxidation combustion as well as char combustion. The main mass loss of biomass blends occurred at volatile emission and oxidation combustion stage, while that of torrefied biomass occurred at char combustion stage. With the increase of bamboo content, characteristic temperatures decreased. Compared with untreated biomass, torrefied biomass had a higher initial and burnout temperature. With the increase of heating rates, combustion process of samples shifted to higher temperatures. Compared with non-isothermal models, activation energy obtained from isothermal model was lower. The result is helpful to promote development of co-combustion of bamboo and masson pine wastes. Copyright © 2017 Elsevier Ltd. All rights reserved.

New technologies reducing emissions from combustion of biofuels

International Nuclear Information System (INIS)

Oravainen, H.

1997-01-01

In reducing CO 2 emissions, bioenergy will be the most important source of renewable energy in the next few decades. In principle, combustion of biomass is friendly to the environment because CO 2 released during combustion is recycled back into natural circulation. Biofuels normally contain little nitrogen and sulphur. However, depending on the combustion technology used, emissions may be quite high. This is true of combustion of biomass fuels in small appliances like wood stoves, fireplaces, small boilers etc. When fuels having high content of volatile matter are burnt in appliances using batch type combustion, the process is rather an unsteady-state combustion. Emissions of carbon monoxide, other combustible gases and particulates are quite difficult to avoid. With continuous combustion processes this is not normally a problem. This conference paper presents some means of reducing emissions from combustion of biofuels. 5 refs., 4 figs

Co-combustion of anthracite coal and wood pellets: Thermodynamic analysis, combustion efficiency, pollutant emissions and ash slagging.

Science.gov (United States)

Guo, Feihong; Zhong, Zhaoping

2018-08-01

This work presents studies on the co-combustion of anthracite coal and wood pellets in fluidized bed. Prior to the fluidized bed combustion, thermogravimetric analysis are performed to investigate the thermodynamic behavior of coal and wood pellets. The results show that the thermal decomposition of blends is divided into four stages. The co-firing of coal and wood pellets can promote the combustion reaction and reduce the emission of gaseous pollutants, such as SO 2 and NO. It is important to choose the proportion of wood pellets during co-combustion due to the low combustion efficiency caused by large pellets with poor fluidization. Wood pellets can inhibit the volatilization of trace elements, especially for Cr, Ni and V. In addition, the slagging ratio of wood pellets ash is reduced by co-firing with coal. The research on combustion of coal and wood pellets is of great significance in engineering. Copyright © 2018 Elsevier Ltd. All rights reserved.

Bases para proyectiles dirigidos

Directory of Open Access Journals (Sweden)

Editorial, Equipo

1959-03-01

Full Text Available Aunque actualmente no se ha llegado a una línea general de métodos o sistemas que gobiernen un tipo característico de rampa y servicios auxiliares necesarios para el lanzamiento al espacio de proyectiles dirigidos a grandes alturas y distancias, las experiencias obtenidas en diferentes ensayos, utilizando distintos tipos de proyectiles y trayectorias balísticas, han sentado toda una serie de procedimientos, datos y conclusiones de gran valor balístico que, aun teniendo en cuenta la continua evolución del proyectil, sus formas, combustibles y alcances, se conocen ya, con bastante aproximación, las condiciones mínimas que ha de reunir una base dedicada a este tipo de lanzamientos.

Naphtha vs. dieseline – The effect of fuel properties on combustion homogeneity in transition from CI combustion towards HCCI

KAUST Repository

Vallinayagam, R.

2018-03-20

The scope of this research study pertains to compare the combustion and emission behavior between naphtha and dieseline at different combustion modes. In this study, US dieseline (50% US diesel + 50% RON 91 gasoline) and EU dieseline (45% EU diesel + 55% RON 97 gasoline) with derived cetane number (DCN) of 36 are selected for experimentation in an optical engine. Besides naphtha and dieseline, PRF60 is also tested as a surrogate fuel for naphtha. For the reported fuel with same RON = 60, the effect of physical properties on combustion homogeneity when moving from homogenized charge compression ignition (HCCI) to compression ignition (CI) combustion is studied.The combustion phasing of naphtha at an intake air temperature of 95 °C is taken as the baseline data. The engine experimental results show that higher and lower intake air temperature is required for dieseline mixtures to have same combustion phasing as that of naphtha at HCCI and CI conditions due to the difference in the physical properties. Especially at HCCI mode, due to wider distillation range of dieseline, the evaporation of the fuel is affected so that the gas phase mixture becomes too lean to auto-ignite. However, at partially premixed combustion (PPC) conditions, all test fuels required almost same intake air temperature to match up with the combustion phasing of baseline naphtha. From the rate of heat release and combustion images, it was found that naphtha and PRF60 showed improved premixed combustion when compared dieseline mixtures. The stratification analysis shows that combustion is more stratified for dieseline whereas it is premixed for naphtha and PRF60. The level of stratification linked with soot emission showed that soot concentration is higher at stratified CI combustion whereas near zero soot emissions were noted at PPC mode.

Comparison of different chemical kinetic mechanisms of methane combustion in an internal combustion engine configuration

OpenAIRE

Ennetta Ridha; Hamdi Mohamed; Said Rachid

2008-01-01

Three chemical kinetic mechanisms of methane combustion were tested and compared using the internal combustion engine model of Chemkin 4.02 [1]: one-step global reaction mechanism, four-step mechanism, and the standard detailed scheme GRIMECH 3.0. This study shows good concordances, especially between the four-step and the detailed mechanisms in the prediction of temperature and main species profiles. But reduced schemes were incapables to predict pollutant emissions in an internal combustion...

Burning Questions in Gravity-Dependent Combustion Science

Science.gov (United States)

Urban, David; Chiaramonte, Francis P.

2012-01-01

Building upon a long history of spaceflight and ground based research, NASA's Combustion Science program has accumulated a significant body of accomplishments on the ISS. Historically, NASAs low-gravity combustion research program has sought: to provide a more complete understanding of the fundamental controlling processes in combustion by identifying simpler one-dimensional systems to eliminate the complex interactions between the buoyant flow and the energy feedback to the reaction zone to provide realistic simulation of the fire risk in manned spacecraft and to enable practical simulation of the gravitational environment experienced by reacting systems in future spacecraft. Over the past two decades, low-gravity combustion research has focused primarily on increasing our understanding of fundamental combustion processes (e.g. droplet combustion, soot, flame spread, smoldering, and gas-jet flames). This research program was highly successful and was aided by synergistic programs in Europe and in Japan. Overall improvements were made in our ability to model droplet combustion in spray combustors (e.g. jet engines), predict flame spread, predict soot production, and detect and prevent spacecraft fires. These results provided a unique dataset that supports both an active research discipline and also spacecraft fire safety for current and future spacecraft. These experiments have been conducted using the Combustion Integrated Rack (CIR), the Microgravity Science Glovebox and the Express Rack. In this paper, we provide an overview of the earlier space shuttle experiments, the recent ISS combustion experiments in addition to the studies planned for the future. Experiments in combustion include topics such as droplet combustion, gaseous diffusion flames, solid fuels, premixed flame studies, fire safety, and super critical oxidation processes.

75 FR 6305 - Approval and Promulgation of Air Quality Implementation Plans; West Virginia; Removal of NOX

Science.gov (United States)

2010-02-09

... the electric generating units (EGUs) that are subject to the NO X SIP Call but does not apply to the... to recodify the provisions for its non-trading non-EGUs (internal combustion engines and cement kilns... and Reduction of Nitrogen Oxides from Non-Electric Generating Units As a Means to Mitigate Transport...

Modelo estadístico que permite observar el impacto de los factores que inciden en el rendimiento de combustible

Directory of Open Access Journals (Sweden)

Rosa Amelia Alcántar Ruiz

2015-01-01

Full Text Available El presente trabajo propone un modelo estadístico de regresión lineal múltiple para la toma de decisiones sobre el rendimiento de combustible con aplicación a la industria del autotransporte en México considerando los factores con mayor incidencia en el consumo. El modelo aplicado tiene significancia estadística, así como las variables explicativas: tipo de ruta, antigüedad y cantidad de diésel consumido en baja, esto con un nivel de confianza del 95%, lográndose explicar un 94% del efecto de interés modelado. La contribución fundamental de este artículo es proponer un modelo estadístico como una nueva herramienta de gestión para los tomadores de decisiones del sector, en relación al establecimiento de estándares de combustible y la administración en general de este insumo, puesto que fue determinado a partir de las condiciones operativas de la industria del transporte y no bajo condiciones experimentales (difíciles de replicar empleadas por el fabricante del automotor.

Lignina organosolv de Eucalyptus dunnii maiden, alternativa para a síntese de adesivos de poliuretano para madeira

OpenAIRE

Anzaldo Hernández, José

2013-01-01

Por muitos anos a lignina tem sido utilizada como combustível para a geração de energia na indústria da celulose. Porém no transcorrer dos anos, as empresas de celulose têm aumentado a capacidade produtiva, isto traz como conseqüência que, algumas delas tenham excedentes de lignina que pode ser aproveitada na obtenção de outros materiais. Atualmente são comercializadas as ligninas técnicas (lignina Kraft e lignosulfonatos) que têm mercado específico como agentes de flotação, dispersante, cond...

Experimental study of combustion and emission characteristics of ethanol fuelled port injected homogeneous charge compression ignition (HCCI) combustion engine

Energy Technology Data Exchange (ETDEWEB)

Maurya, Rakesh Kumar; Agarwal, Avinash Kumar [Engine Research Laboratory, Department of Mechanical Engineering, Indian Institute of Technology Kanpur, Kanpur 208 016 (India)

2011-04-15

The homogeneous charge compression ignition (HCCI) is an alternative combustion concept for in reciprocating engines. The HCCI combustion engine offers significant benefits in terms of its high efficiency and ultra low emissions. In this investigation, port injection technique is used for preparing homogeneous charge. The combustion and emission characteristics of a HCCI engine fuelled with ethanol were investigated on a modified two-cylinder, four-stroke engine. The experiment is conducted with varying intake air temperature (120-150 C) and at different air-fuel ratios, for which stable HCCI combustion is achieved. In-cylinder pressure, heat release analysis and exhaust emission measurements were employed for combustion diagnostics. In this study, effect of intake air temperature on combustion parameters, thermal efficiency, combustion efficiency and emissions in HCCI combustion engine is analyzed and discussed in detail. The experimental results indicate that the air-fuel ratio and intake air temperature have significant effect on the maximum in-cylinder pressure and its position, gas exchange efficiency, thermal efficiency, combustion efficiency, maximum rate of pressure rise and the heat release rate. Results show that for all stable operation points, NO{sub x} emissions are lower than 10 ppm however HC and CO emissions are higher. (author)

Catalytically enhanced combustion process

International Nuclear Information System (INIS)

Rodriguez, C.

1992-01-01

This patent describes a fuel having improved combustion efficiency. It comprises a petroleum based liquid hydrocarbon; and a combustion catalyst comprising from about 18 to about 21 weight percent naphthalene, from about 75 to about 80 weight percent toluene, and from about 2.8 to about 3.2 weight percent benzyl alcohol

Impact of higher n-butanol addition on combustion and performance of GDI engine in stoichiometric combustion

International Nuclear Information System (INIS)

Chen, Zheng; Yang, Feng; Xue, Shuo; Wu, Zhenkuo; Liu, Jingping

2015-01-01

Highlights: • Effects of 0–50% n-butanol addition on GDI engine are experimentally studied. • Higher n-butanol fractions increase combustion pressure and fasten burning rate. • Higher n-butanol fractions increase BSFC but improve BTE. • Higher n-butanol fractions enhance combustion stability but increase knock intensity. • Higher n-butanol fractions reduce exhaust temperature and NOx emissions. - Abstract: An experimental study was carried out on a turbocharged gasoline direct injection (GDI) engine fueled by n-butanol/gasoline blends. Effects of n-butanol percents (15%, 30%, and 50%) on combustion and performance of the engine operating on stoichiometric combustion condition were discussed and also compared with pure gasoline in this paper. The results indicate that n-butanol/gasoline blends increase combustion pressure and pressure rise rate, fasten burning rate, and shorten ignition delay and combustion duration, as compared to pure gasoline. Moreover, these trends are impacted more evidently with increased n-butanol fraction in the blends. In addition, higher n-butanol percent of gasoline blends increase combustion temperature but decrease the temperature in the later stage of expansion stroke, which contributes to the control of exhaust temperature at high-load. With regards to engine performance, higher n-butanol percent in the blends results in increased brake specific fuel consumption (BSFC) and higher brake thermal efficiency (BTE). However, higher n-butanol addition helps to improve combustion stability but shows slightly higher knock possibility in high-load. In that case, the knock trend could be weakened by retarding ignition timing. Moreover, higher n-butanol addition significantly decreases NOx emissions, but it increases CO emissions obviously.

Characterization of para-Nitrophenol-Degrading Bacterial Communities in River Water by Using Functional Markers and Stable Isotope Probing.

Science.gov (United States)

Kowalczyk, Agnieszka; Eyice, Özge; Schäfer, Hendrik; Price, Oliver R; Finnegan, Christopher J; van Egmond, Roger A; Shaw, Liz J; Barrett, Glyn; Bending, Gary D

2015-10-01

Microbial degradation is a major determinant of the fate of pollutants in the environment. para-Nitrophenol (PNP) is an EPA-listed priority pollutant with a wide environmental distribution, but little is known about the microorganisms that degrade it in the environment. We studied the diversity of active PNP-degrading bacterial populations in river water using a novel functional marker approach coupled with [(13)C6]PNP stable isotope probing (SIP). Culturing together with culture-independent terminal restriction fragment length polymorphism analysis of 16S rRNA gene amplicons identified Pseudomonas syringae to be the major driver of PNP degradation in river water microcosms. This was confirmed by SIP-pyrosequencing of amplified 16S rRNA. Similarly, functional gene analysis showed that degradation followed the Gram-negative bacterial pathway and involved pnpA from Pseudomonas spp. However, analysis of maleylacetate reductase (encoded by mar), an enzyme common to late stages of both Gram-negative and Gram-positive bacterial PNP degradation pathways, identified a diverse assemblage of bacteria associated with PNP degradation, suggesting that mar has limited use as a specific marker of PNP biodegradation. Both the pnpA and mar genes were detected in a PNP-degrading isolate, P. syringae AKHD2, which was isolated from river water. Our results suggest that PNP-degrading cultures of Pseudomonas spp. are representative of environmental PNP-degrading populations. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Spray combustion of Jet-A and diesel fuels in a constant volume combustion chamber

KAUST Repository

Jing, Wei; Roberts, William L.; Fang, Tiegang

2015-01-01

This work investigates the spray combustion of Jet-A fuel in an optical constant-volume combustion chamber under different ambient initial conditions. Ambient temperature was varied at 800 K, 1000 K, and 1200 K and five different ambient O2

Experimental study on the influence of oxygen content in the combustion air on the combustion characteristics

International Nuclear Information System (INIS)

Bělohradský, Petr; Skryja, Pavel; Hudák, Igor

2014-01-01

This study was focused on the experimental investigation of the very promising combustion technology called as the oxygen-enhanced combustion (OEC), which uses the oxidant containing higher proportion of oxygen than in the atmospheric air, i.e. more than 21%. The work investigated and compared the characteristics of two OEC methods, namely the premix enrichment and air-oxy/fuel combustion, when the overall oxygen concentration was varied from 21% to 46%. The combustion tests were performed with the experimental two-gas-staged burner of low-NO x type at the burner thermal input of 750 kW for two combustion regimes – one-staged and two-staged combustion. The oxygen concentration in the flue gas was maintained in the neighborhood of 3% vol. (on dry basis). The aim of tests was to assess the impact of the oxidant composition, type of OEC method and fuel-staging on the characteristic combustion parameters in detail. The investigated parameters included the concentration of nitrogen oxides (NO x ) in the flue gas, flue gas temperature, heat flux to the combustion chamber wall, and lastly the stability, shape and dimensions of flame. It was observed that NO x emission is significantly lower when the air-oxy/fuel method is used compared to the premix enrichment method. Moreover, when the fuel was staged, NO x emission was below 120 mg/Nm 3 at all investigated oxygen flow rates. Increasing oxygen concentration resulted in higher heating intensity due to higher concentrations of CO 2 and H 2 O. The available heat at 46% O 2 was higher by 20% compared with that at 21% O 2 . - Highlights: • Premix-enrichment and air-oxy/fuel combustion methods were experimentally studied. • NO x increased sharply as oxygen concentration increased during PE tests. • NO x was below 120 mg/Nm 3 for all investigated oxygen flow rates in AO tests. • Radiative heat transfer was enhanced ca. 20% as O 2 concentration was increased. • OEC flames were observed stable, more luminous and

Combustion modeling in waste tanks

International Nuclear Information System (INIS)

Mueller, C.; Unal, C.; Travis, J.R.; Forschungszentrum Karlsruhe

1997-01-01

This paper has two objectives. The first one is to repeat previous simulations of release and combustion of flammable gases in tank SY-101 at the Hanford reservation with the recently developed code GASFLOW-II. The GASFLOW-II results are compared with the results obtained with the HMS/TRAC code and show good agreement, especially for non-combustion cases. For combustion GASFLOW-II predicts a steeper pressure rise than HMS/TRAC. The second objective is to describe a so-called induction parameter model which was developed and implemented into GASFLOW-II and reassess previous calculations of Bureau of Mines experiments for hydrogen-air combustion. The pressure time history improves compared with the one-step model, and the time rate of pressure change is much closer to the experimental data

Ignition and wave processes in combustion of solids

CERN Document Server

Rubtsov, Nickolai M; Alymov, Michail I

2017-01-01

This book focuses on the application of classical combustion theory to ignition and flame propagation in solid-solid and gas-solid systems. It presents experimental investigations in the areas of local ignition, filtration combustion, self-propagating high temperature synthesis and nanopowders protection. The authors highlight analytical formulas used in different areas of combustion in solids and propose an approach based on classical combustion theory. The book attempts to analyze the basic approaches to understanding of solid-solid and solid - gas combustion presented in contemporary literature in a unified approach based on classical combustion theory. .

Effects of stepwise gas combustion on NOx generation

International Nuclear Information System (INIS)

Woperane Seredi, A.; Szepesi, E.

1999-01-01

To decrease NO x emission from gas boilers, the combustion process of gas has been modified from continuous combustion to step-wise combustion. In this process the combustion temperature, the temperature peaks in the flame, the residence time of combustion products in the high-temperature zone and the oxygen partial pressure are changed advantageously. Experiments were performed using multistage burners, and the NO x emission was recorded. It was found that the air factor of the primary combustion space has a determining effect on the NO x reduction. (R.P.)

Fuel Combustion and Engine Performance | Transportation Research | NREL

Science.gov (United States)

Fuel Combustion and Engine Performance Fuel Combustion and Engine Performance Photo of a gasoline emissions in advanced engine technologies. Photo by Dennis Schroeder, NREL NREL's combustion research and combustion and engine research activities include: Developing experimental and simulation research platforms

Fuel location, homogeneity and amount in flat and tubular configurations; Repartition, Homogeneite et Quantite du Combustible dans les Elements a Configuration Plate ou Tubulaire; Polozhenie, gomogennost' i kolichestvo topliva v ploskikh i trubchatykh konfiguratsiyakh; Disposicion, Homogeneidad y Cantidad de Combustibles en Configuraciones Planas y Tubulares

Energy Technology Data Exchange (ETDEWEB)

Meester, P. de [Studiecentrum voor Kernenergie, Mol (Belgium)

1965-10-15

controler les caracteristiques de deformabilite et les formes finales. La mesure de l'absorption a l'aide d'une source activee donne des resultats moins satisfaisants. L'auteur discute les donnees numeriques obtenues a partir de mesures statiques et d'enregistrements continus Il faut connaitre la quantite absolue de combustible par zone pour le calcul des parametres de fonctionnement du reacteur, et par element pour la comptabilite du combustible ainsi qu'aux fins de comparaison des taux d'irradiation. Le memoire traite de la fabrication et de l'utilisation des divers etalons. Il discute le degre de precision et l'elimination des erreurs. L'auteur propose plusieurs ameliorations des operations de controle. (author) [Spanish] Los elementos combustibles para el reactor de ensayo de materiales BR-2 pueden armarse con placas tipo cuadro, o bien con tubos preparados por coextrusion. En el curso de la elaboracion y antes de cargar el reactor, es nesesario verificar o medir la disposicion, homogeneidad y cantidad absoluta de combustible. La disposicion del combustible debe conocerse para fijar la ubicacion del alma en placas y tubos, y tambien como primera evaluacion de la calidad del producto en lo que atane a las especificaciones sobre su forma geometrica. Se han efectuado inspecciones mediante radiografia a unos 80-90 keV, autorradiograffa y gammagraffa con una fuente de {sup 170}Tm. Para radiografiar los tubos de combustible, se coloco en su interior un mandril de plomo al cual se habfa fijado la pelicula de rayos X y se tomaron luego varias exposiciones desde distintos angulos. Una fuente radiactiva usada para explorar el tubo longitudinalmente, combinada con una pelicula dispuesta alrededor del tubo, permitio obtener registros de elevada resolucion. La homogeneidad del combustible debe controlarse con miras a un foncionamiento seguro del reactor, es decir, se han de evitar por una parte concentraciones excesivas de combustible que podrian producir vapor en el reactor de agua

Specifics of phytomass combustion in small experimental device

Science.gov (United States)

Lenhard, Richard; Mičieta, Jozef; Jandačka, Jozef; Gavlas, Stanislav

2015-05-01

A wood pellet combustion carries out with high efficiency and comfort in modern pellet boilers. These facts help to increase the amount of installed pellet boilers in households. The combustion process quality depends besides the combustion conditions also on the fuel quality. The wood pellets, which don`t contain the bark and branches represent the highest quality. Because of growing pellet demand, an herbal biomass (phytomass), which is usually an agricultural by-product becomes economically attractive for pellet production. Although the phytomass has the net calorific value relatively slightly lower than the wood biomass, it is often significantly worse in view of the combustion process and an emission production. The combustion of phytomass pellets causes various difficulties in small heat sources, mainly due to a sintering of fuel residues. We want to avoid the ash sintering by a lowering of temperature in the combustion chamber below the ash sintering temperature of phytomass via the modification of a burner design. For research of the phytomass combustion process in the small boilers is constructed the experimental combustion device. There will investigate the impact of cooling intensity of the combustion chamber on the combustion process and emissions. Arising specific requirements from the measurement will be the basis for the design of the pellet burner and for the setting of operating parameters to the trouble-free phytomass combustion was guaranteed.

Specifics of phytomass combustion in small experimental device

Directory of Open Access Journals (Sweden)

Lenhard Richard

2015-01-01

Full Text Available A wood pellet combustion carries out with high efficiency and comfort in modern pellet boilers. These facts help to increase the amount of installed pellet boilers in households. The combustion process quality depends besides the combustion conditions also on the fuel quality. The wood pellets, which don`t contain the bark and branches represent the highest quality. Because of growing pellet demand, an herbal biomass (phytomass, which is usually an agricultural by-product becomes economically attractive for pellet production. Although the phytomass has the net calorific value relatively slightly lower than the wood biomass, it is often significantly worse in view of the combustion process and an emission production. The combustion of phytomass pellets causes various difficulties in small heat sources, mainly due to a sintering of fuel residues. We want to avoid the ash sintering by a lowering of temperature in the combustion chamber below the ash sintering temperature of phytomass via the modification of a burner design. For research of the phytomass combustion process in the small boilers is constructed the experimental combustion device. There will investigate the impact of cooling intensity of the combustion chamber on the combustion process and emissions. Arising specific requirements from the measurement will be the basis for the design of the pellet burner and for the setting of operating parameters to the trouble-free phytomass combustion was guaranteed.

Research and development of hydrogen and fuel cells technology at the IIE; Investigacion y desarrollo de tecnologia de hidrogeno y celdas de combustible en el IIE

Energy Technology Data Exchange (ETDEWEB)

Cano C, Ulises; Arriaga H, Gerardo; Romero C, T; Medrano V, M. Consolacion; Gonzalez, A. [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

2005-07-01

In April, 2001, a fuel cells project was initiated at the Instituto de Investigaciones Electricas (IIE) as a part of the interest of this institution for such a technology. Towards end of that same year, a group dedicated to research and development (R and D) activities was implemented and efforts were initiated for the assembly of a laboratory with specialized infrastructure that would support these activities. Thus, in the last two years, the hydrogen and fuel cells group has taken under its responsibility the task of renewing and conditioning a space to receive specialized instrumentation and to initiate its operation, as well as to develop its own knowledge on the technology of fuel cells. The R and D work related to fuel cells was initiated from basic electrochemical studies of platinum electrodes on vitreous coal in acid solutions, to determine kinetic parameters and structural properties. Since the main components of PEM cells to a great extent define the cost of the technology, other additional efforts related to basic studies for the development of components as bipolar plates, are described by the same author in 2001. Other work on basic research is bound to the response of fuel monocells under different operation conditions, and that also will be reviewed in this article. [Spanish] En abril del 2001, se inicio un proyecto de celdas de combustible en el IIE como parte del interes de esta institucion por tal tecnologia. Hacia finales de ese mismo ano, se conformo un grupo dedicado a actividades de investigacion y desarrollo (I y D) y se iniciaron esfuerzos para el montaje de un laboratorio con infraestructura especializada que apoyara estas actividades. Asi, en los ultimos dos anos, el grupo de hidrogeno y celdas de combustible se ha dado a la tarea de renovar y acondicionar un espacio para recibir instrumentacion especializada e iniciar su operacion, asi como a desarrollar su propio conocimiento de tecnologia de celdas de combustible. Los trabajos de I y

Traveling-Wave Thermoacoustic Engines With Internal Combustion

Science.gov (United States)

Weiland, Nathan Thomas; Zinn, Ben T.; Swift, Gregory William

2004-05-11

Thermoacoustic devices are disclosed wherein, for some embodiments, a combustion zone provides heat to a regenerator using a mean flow of compressible fluid. In other embodiments, burning of a combustible mixture within the combustion zone is pulsed in phase with the acoustic pressure oscillations to increase acoustic power output. In an example embodiment, the combustion zone and the regenerator are thermally insulated from other components within the thermoacoustic device.

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.

The effect of insulated combustion chamber surfaces on direct-injected diesel engine performance, emissions, and combustion

Science.gov (United States)

Dickey, Daniel W.; Vinyard, Shannon; Keribar, Rifat

1988-01-01

The combustion chamber of a single-cylinder, direct-injected diesel engine was insulated with ceramic coatings to determine the effect of low heat rejection (LHR) operation on engine performance, emissions, and combustion. In comparison to the baseline cooled engine, the LHR engine had lower thermal efficiency, with higher smoke, particulate, and full load carbon monoxide emissions. The unburned hydrocarbon emissions were reduced across the load range. The nitrous oxide emissions increased at some part-load conditions and were reduced slightly at full loads. The poor LHR engine performance was attributed to degraded combustion characterized by less premixed burning, lower heat release rates, and longer combustion duration compared to the baseline cooled engine.

Improved Economic Performance of Municipal Solid Waste Combustion Plants by Model Based Combustion Control

NARCIS (Netherlands)

Leskens, M.

2013-01-01

The combustion of municipal solid waste (MSW) is used for its inertisation, reduction of its volume and the conversion of its energy content into heat and/or electricity. Operation and control of modern large scale MSW combustion (MSWC) plants is determined by economic and environmental objectives

Toxicology of Biodiesel Combustion products

Science.gov (United States)

1. Introduction The toxicology of combusted biodiesel is an emerging field. Much of the current knowledge about biological responses and health effects stems from studies of exposures to other fuel sources (typically petroleum diesel, gasoline, and wood) incompletely combusted. ...

Double crystal X-ray analysis of phosphorus precipitation in supersaturated Si-P solid solutions

International Nuclear Information System (INIS)

Servidori, M.; Zini, Q.; Dal Monte, C.

1983-01-01

The physical nature of the electrically inactive phosphorus in silicon is investigated by double crystal X-ray diffraction measurements. This analysis is performed on laser annealed supersaturated samples, doped by ion implantation up to 5 x 10 21 cm -3 . After isothermal heat treatments, these solid solutions show marked reductions in the electrically active phosphorus concentration. In particular, 850 0 C heatings give rise to a carrier concentration which corresponds to the phosphorus solubility in equilibrium with the inactive dopant. This dopant is characterized by means of lattice strain measurements: they are found consistent with the presence of perfectly coherent cubic SiP precipitates. This result is in agreement with the one obtained in preceeding works by electrical measurements and transmission electron microscopy observations and contradicts the hypothesis that the excess dopant atoms are, at least in part, charged point defects (E-centres). (author)

Uso de detectores de neutrinos para el monitoreo de reactores nucleares Uso de detectores de neutrinos para el monitoreo de reactores nucleares

Directory of Open Access Journals (Sweden)

Gerardo Moreno

2012-02-01

Full Text Available Se estudia la factibilidad del uso de los detectores de antineutrinos para el monitoreo de reactores nucleares. Usando un modelo sencillo de cascada de fisión a dos componentes, se ilustra la dependencia del número de antineutrinos detectados a una distancia L del reactor según la composición nuclear del combustible. Se explica el principio de detección de neutrinos de reactores en base al decaimiento beta inverso y se describe como los detectores de neutrinos pueden emplearse para el monitoreo de la producción de materiales fisibles en el reactor. Se comenta como generalizar este análisis al caso real de un reactor nuclear in situ y uno de los principales experimentos internacionales dedicados a este propósito. We study the feasibility to use antineutrinos detectors for monitoring of nuclear reactors. Using a simple model of fission shower with two components, we illustrate how the numbers of antineutrinos detected at a distance L from the reactor depend on the composition of the nuclear combustible. We explain the principles of reactor neutrino detection using inverse beta decays and we describe how neutrinos detectors can be used for monitoring the production of fissile materials within the reactors. We comment how to generalize this analysis to the realistic case of a nuclear reactor in situ and one of the main international experiments dedicated to study the use of neutrinos detectors as nuclear safeguards.

Producer for vegetal combustibles for internal-combustion motors

Energy Technology Data Exchange (ETDEWEB)

1943-12-28

A producer is described for internal-combustion motors fed with wood or agricultural byproducts characterized by the fact that its full operation is independent of the degree of wetness of the material used.

Investigation of bluff-body micro-flameless combustion

International Nuclear Information System (INIS)

Hosseini, Seyed Ehsan; Wahid, Mazlan Abdul

2014-01-01

Highlights: • The temperature uniformity of the micro-flameless combustion increases when a triangular bluff-body is applied. • The velocity and temperature of exhaust gases are higher in micro-flameless combustion compared to the conventional mode. • The rate of fuel–oxidizer consumption in micro-flameless mode is lower than conventional micro-combustion. - Abstract: Characteristics of lean premixed conventional micro-combustion and lean non-premixed flameless regime of methane/air are investigated in this paper by solving three-dimensional governing equations. At moderate equivalence ratio (∅ = 0.5), standard k–ε and the eddy-dissipation concept are employed to simulate temperature distribution and combustion stability of these models. The effect of bluff-body on the temperature distribution of both conventional and flameless mode is developed. The results show that in the premixed conventional micro-combustion the stability of the flame is increased when a triangular bluff-body is applied. Moreover, micro-flameless combustion is more stable when bluff-body is used. Micro-flameless mode with bluff-body and 7% O 2 concentration (when N 2 is used as diluent) illustrated better performance than other cases. The maximum temperature in premixed conventional micro-combustion and micro-flameless combustion was recorded 2200 K and 1520 K respectively. Indeed, the flue gas temperature of conventional mode and flameless combustion was 1300 K and 1500 K respectively. The fluctuation of temperature in the conventional micro-combustor wall has negative effects on the combustor and reduces the lifetime of micro-combustor. However, in the micro-flameless mode, the wall temperature is moderate and uniform. The rate of fuel–oxidizer consumption in micro-flameless mode takes longer time and the period of cylinders recharging is prolonged

Numerical analysis on the combustion and emission characteristics of forced swirl combustion system for DI diesel engines

International Nuclear Information System (INIS)

Su, LiWang; Li, XiangRong; Zhang, Zheng; Liu, FuShui

2014-01-01

Highlights: • A new combustion system named FSCS for DI diesel engines was proposed. • Fuel/air mixture formation was improved for the application of FSCS. • The FSCS showed a good performance on emission characteristics. - Abstract: To optimize the fuel/air mixture formation and improve the environmental effect of direct injection (DI) diesel engines, a new forced swirl combustion system (FSCS) was proposed concerned on unique design of the geometric shape of the combustion chamber. Numerical simulation was conducted to verify the combustion and emission characteristics of the engines with FSCS. The fuel/air diffusion, in-cylinder velocity distribution, turbulent kinetic energy and in-cylinder temperature distribution were analyzed and the results shown that the FSCS can increase the area of fuel/air diffusion and improve the combustion. The diesel engine with FSCS also shown excellent performance on emission. At full load condition, the soot emission was significantly reduced for the improved fuel/air mixture formation. There are slightly difference for the soot and NO emission between the FSCS and the traditional omega combustion system at lower load for the short penetration of the fuel spray

Combustion & Laser Diagnostics Research Complex (CLDRC)

Data.gov (United States)

Federal Laboratory Consortium — Description: The Combustion and Laser Diagnostics Research Complex (CLRDC) supports the experimental and computational study of fundamental combustion phenomena to...

Study of temperature distribution of pipes heated by moving rectangular gauss distribution heat source. Development of pipe outer surface irradiated laser stress improvement process (L-SIP)

International Nuclear Information System (INIS)

Ohta, Takahiro; Kamo, Kazuhiko; Asada, Seiji; Terasaki, Toshio

2009-01-01

The new process called L-SIP (outer surface irradiated Laser Stress Improvement Process) is developed to improve the tensile residual stress of the inner surface near the butt welded joints of pipes in the compression stress. The temperature gradient occurs in the thickness of pipes in heating the outer surface rapidly by laser beam. By the thermal expansion difference between the inner surface and the outer surface, the compression stress occurs near the inner surface of pipes. In this paper, the theoretical equation for the temperature distributions of pipes heated by moving rectangular Gauss distribution heat source on the outer surface is derived. The temperature histories of pipes calculated by theoretical equation agree well with FEM analysis results. According to the theoretical equation, the controlling parameters of temperature distributions and histories are q/2a y , vh, a x /h and a y /h, where q is total heat input, a y is heat source length in the axial direction, a x is Gaussian radius of heat source in the hoop direction, ν is moving velocity, and h is thickness of the pipe. The essential variables for L-SIP, which are defined on the basis of the measured temperature histories on the outer surface of the pipe, are Tmax, F 0 =kτ 0 /h 2 , vh, W Q and L Q , where Tmax is maximum temperature on the monitor point of the outer surface, k is thermal diffusivity coefficient, τ 0 is the temperature rise time from 100degC to maximum temperature on the monitor point of the outer surface, W Q is τ 0 x ν, and L Q is the uniform temperature length in the axial direction. It is verified that the essential variables for L-SIP match the controlling parameters by the theoretical equation. (author)

The rheodynamics and combustion of coal-water mixtures

Energy Technology Data Exchange (ETDEWEB)

Burdukov, A.P.; Popov, V.I.; Tomilov, V.G.; Fedosenko, V.D. [Russian Academy of Science, Novosibirsk (Russian Federation). Inst. of Thermophysics (Siberian Branch, Russian Academy of Science)

2002-05-01

Investigation methods for characteristics of movement along the tubes, combustion dynamics and gasification of separate drops were developed for the coal-water mixtures (CWM). The following parameters were determined on the basis of laser heating: thermometric, pyrometric and concentration dynamics of single-drop combustion, complete combustion times, duration of temperature phases of combustion, as well as the moment and temperature of ignition. Information on the combustion mass velocity and gasification products was also obtained using laser heating. 6 refs., 13 figs., 1 tab.

Bifurcation, pattern formation and chaos in combustion

International Nuclear Information System (INIS)

Bayliss, A.; Matkowsky, B.J.

1991-01-01

In this paper problems in gaseous combustion and in gasless condensed phase combustion are studied both analytically and numerically. In gaseous combustion we consider the problem of a flame stabilized on a line source of fuel. The authors find both stationary and pulsating axisymmetric solutions as well as stationary and pulsating cellular solutions. The pulsating cellular solutions take the form of either traveling waves or standing waves. Transitions between these patterns occur as parameters related to the curvature of the flame front and the Lewis number are varied. In gasless condensed phase combustion both planar and nonplanar problems are studied. For planar condensed phase combustion we consider two models: accounts for melting and does not. Both models are shown to exhibit a transition from uniformly to pulsating propagating combustion when a parameter related to the activation energy is increased. Upon further increasing this parameter both models undergo a transition to chaos: by intermittency and by a period doubling sequence. In nonplanar condensed phase combustion the nonlinear development of a branch of standing wave solutions is studied and is shown to lead to relaxation oscillations and subsequently to a transition to quasi-periodicity

Fundamentals of Turbulent and Multi-Phase Combustion

CERN Document Server

Kuo, Kenneth Kuan-yun

2012-01-01

Detailed coverage of advanced combustion topics from the author of Principles of Combustion, Second Edition Turbulence, turbulent combustion, and multiphase reacting flows have become major research topics in recent decades due to their application across diverse fields, including energy, environment, propulsion, transportation, industrial safety, and nanotechnology. Most of the knowledge accumulated from this research has never been published in book form-until now. Fundamentals of Turbulent and Multiphase Combustion presents up-to-date, integrated coverage of the fundamentals of turbulence

Ultrasonic Water-Gap Measurements in MTR Fuel Elements; Mesure par Ultrasons des Espaces Intercalaires dans les Elements Combustibles des Reacteurs d'Essai de Materiaux; Izmereniya vodyanogo zazora v teplovydelyayushchikh ehlementakh dlya materialovedcheskogo reaktora s pomoshch'yu ul'trazvuka; Medicion Ultrasonica de la Capa de Agua en Elementos Combustibles para Reactores de Ensayo de Materiales

Energy Technology Data Exchange (ETDEWEB)

Deknock, R. [Metallurgy Department, S.C.K./C.E.N., Mol (Belgium)

1965-10-15

distance intercalaire fournit a un enregistreur une tension stable de sortie de 1 V. Il est facile de mesurer les variations des distances intercalaires avec une precision de 5 {mu}m. Les mesures ont ete faites pour plusieurs elements combustibles. Les resultats et la reproductibilite sont tres satisfaisants. (author) [Spanish] Los elevados flujos termicos que suelen alcanzarse en los recientes reactores de ensayo de materiales, exigen recorridos adecuados para lograr una transmisiun uniforme de calor y una disipacion segura del mismo, evitando asf la formacion de vapor en la masa. Ademas, a fin de controlar el hinchamiento y el comportamiento del combustible en el reactor, tambien debe medirse la capa de agua en experimentos realizados despues de la irradiacion, con elementos combustibles agotados. A tal efecto se ha disenado una sonda ultrasonica destinada a medir, en una longitud de 1 m el espesor de 3 mm de agua correspondiente al elemento combustible BR-2. En el caso de los experimentos posteriores a la irradiacion, es necesario trabajar con el elemento combustible sumergido en un tanque de agua, a profundidad no menor de 6 m. La sonda puede resistir una prolongada inmersion en agua, y no le afectan las dosis normales de radiacion gamma. Aunque proyectado conforme al metodo usual de reflexion de impulsos, el sistema permite separar pulsos emitidos y reflejados, usando un cristal ferro-electrico de 10 MHz, con elevada disipacion inherente de energia. Puede usarse un osciioscopio para la lectura, en cuyo caso el tiempo se representa en el eje horizontal, regulandose la velocidad de barrido de manera que sea directamente proporcional a la velocidad de propagacion de la onda, es decir, al espesor de la capa de agua. Este tipo de representacion da resultados satisfactorios cuando setrata de un numero limitado de mediciones, pero sin duda resulta mas conveniente el registro grafico. En este caso, se da a los impulsos emitidos y reflejados la forma deseada y se les inyecta

An Assessment of Combustion Dynamics in a Low-Nox, Second-Generation Swirl-Venturi Lean Direct Injection Combustion Concept

Science.gov (United States)

Tacina, K. M.; Chang, C. T.; Lee, P.; Mongia, H.; Podboy, D. P.; Dam, B.

2015-01-01

Dynamic pressure measurements were taken during flame-tube emissions testing of three second-generation swirl-venturi lean direct injection (SV-LDI) combustor configurations. These measurements show that combustion dynamics were typically small. However, a small number of points showed high combustion dynamics, with peak-to-peak dynamic pressure fluctuations above 0.5 psi. High combustion dynamics occurred at low inlet temperatures in all three SV-LDI configurations, so combustion dynamics were explored further at low temperature conditions. A point with greater than 1.5 psi peak-to-peak dynamic pressure fluctuations was identified at an inlet temperature of 450!F, a pressure of 100 psia, an air pressure drop of 3%, and an overall equivalence ratio of 0.35. This is an off design condition: the temperature and pressure are typical of 7% power conditions, but the equivalence ratio is high. At this condition, the combustion dynamics depended strongly on the fuel staging. Combustion dynamics could be reduced significantly without changing the overall equivalence ratio by shifting the fuel distribution between stages. Shifting the fuel distribution also decreased NOx emissions.

Assessment of Literature Related to Combustion Appliance Venting Systems

Energy Technology Data Exchange (ETDEWEB)

Rapp, V. H.; Less, B. D.; Singer, B. C.; Stratton, J. C.; Wray, C. P.

2015-02-01

In many residential building retrofit programs, air tightening to increase energy efficiency is often constrained by safety concerns with naturally vented combustion appliances. Tighter residential buildings more readily depressurize when exhaust equipment is operated, making combustion appliances more prone to backdraft or spill combustion exhaust into the living space. Several measures, such as installation guidelines, vent sizing codes, and combustion safety diagnostics, are in place with the intent to prevent backdrafting and combustion spillage, but the diagnostics conflict and the risk mitigation objective is inconsistent. This literature review summarizes the metrics and diagnostics used to assess combustion safety, documents their technical basis, and investigates their risk mitigations. It compiles information from the following: codes for combustion appliance venting and installation; standards and guidelines for combustion safety diagnostics; research evaluating combustion safety diagnostics; research investigating wind effects on building depressurization and venting; and software for simulating vent system performance.

Flow and Combustion in Advanced Gas Turbine Combustors

CERN Document Server

Janicka, Johannes; Schäfer, Michael; Heeger, Christof

2013-01-01