Thermal properties and kinetics of Al/α-MnO{sub 2} nanostructure thermite

Energy Technology Data Exchange (ETDEWEB)

Song, Jia-Xing; Fang, Xiang; Guo, Tao; Ding, Wen; Zhang, Xiao-Nan; Yao, Miao, E-mail: 1023855857@qq.com [PLA University of Science and Technology, Nanjing (China); Bei, Feng-Li; Yu, Hong-Jun [Nanjing University of Science and Technology (China)

2018-05-01

In this work, thermal properties and kinetics of Al-nanoparticles/α-MnO{sub 2} nanorods thermite were reported. The α-MnO{sub 2} nanorods were synthesized using a hydrothermal method and were characterized by X-ray powder diffraction (XRD) and X-ray photoelectron spectra (XPS), then combined with Al nanoparticles based on the ultrasonic mixing method to prepare the nanostructure thermite. Besides, both pure components and mixture were characterized by field emission scanning electron microscopy (FE-SEM) to observe their morphologies and structures. Subsequently, the thermal properties of Al/α-MnO{sub 2} nanostructure thermite were studied on the basis of thermogravimetric-differential scanning calorimetry (TG-DSC). According to the TG-DSC tests, the calculation results of activation energy for kinetics of Al/α-MnO{sub 2} thermite were obtained using different isoconversional methods. It was found that Al/α-MnO{sub 2} nanostructure thermite has high heat release and low onset temperature, and the heat release of the nanostructure thermite was approximately 1146.6 J g{sup -1}. (author)

Uncontrolled re-entry of satellite parts after finishing their mission in LEO: Titanium alloy degradation by thermite reaction energy

Science.gov (United States)

Monogarov, K. A.; Pivkina, A. N.; Grishin, L. I.; Frolov, Yu. V.; Dilhan, D.

2017-06-01

Analytical and experimental studies conducted at Semenov Institute of Chemical Physics for investigating the use of pyrotechnic compositions, i.e., thermites, to reduce the risk of the fall of thermally stable parts of deorbiting end-of-life LEO satellites on the Earth are described. The main idea was the use of passive heating during uncontrolled re-entry to ignite thermite composition, fixed on the titanium surface, with the subsequent combustion energy release to be sufficient to perforate the titanium cover. It is supposed, that thus destructed satellite parts will lose their streamline shape, and will burn out being aerodynamically heated during further descending in atmosphere (patent FR2975080). On the base of thermodynamic calculations the most promising thermite compositions have been selected for the experimental phase. The unique test facilities have been developed for the testing of the efficiency of thermite charges to perforate the titanium TA6V cover of 0.8 mm thickness under temperature/pressure conditions duplicated the uncontrolled re-entry of titanium tank after its mission on LEO. Experiments with the programmed laser heating inside the vacuum chamber revealed the only efficient thermite composition among preliminary selected ones to be Al/Co3O4. Experimental searching of the optimal aluminum powder between spherical and flaked nano- and micron-sized ones revealed the possibility to adjust the necessary ignition delay time, according to the titanium cover temperature dependency on deorbiting time. For the titanium tank the maximum temperature is 1100 °C at altitude 68 km and pressure 60 Pa. Under these conditions Al/Co3O4 formulations with nano-Al spherical particles provide the ignition time to be 13.3 s, and ignition temperature as low as 592±5 °C, whereas compositions with the micron-sized spherical Al powder reveal these values to be much higher, i.e., 26.3 s and 869±5 °C, respectively. The analytical and experimental studies described

Preparation of Al-Ti-B grain refiner by SHS technology[Self-propagating High-temperature Synthesis

Energy Technology Data Exchange (ETDEWEB)

Nikitin, V.I.; Wanqi, J.I.E.; Kandalova, E.G.; Makarenko, A.G.; Yong, L.

2000-02-01

Since the discovery of the grain refinement effect of aluminum by titanium, especially with the existence of B or C in 1950, grain refiners are widely accepted in industry for microstructure control of aluminum alloys. Research on this topic is to obtain the highest grain refinement efficiency with the lowest possible addition of master alloy. It is widely accepted that the morphology and size of TiAl{sub 3} particles, which are known as heterogeneous nucleation centers, are important factors deterring the grain refinement efficiency. Fine TiAl{sub 3} particles are favorable. The grain refinement process shows a heredity phenomenon, which means that structural information from initial materials transfers through a melt to the final product. It is important to find the connection between microstructural parameters of the master alloy and the final product. To improve the quality of Al-Ti-B master alloys for the use as a grain refiner, a new method based on SHS (self-propagating high-temperature synthesis) technology has been developed in Samara State Technical University to produce the master alloys. SHS, as a new method for preparation of materials, was first utilized by Merzhanov in 1967. This method uses the energy from highly exothermic reactions to sustain the chemical reaction in a combustion wave. The advantages of SHS include simplicity, low energy requirement, and higher product purity. Because SHS reactions can take place between elemental reactants, it is easy to control product composition. The purposes of this investigation were to fabricate an SHS Al-5%Ti-1%B master alloy, to analyze its structure and to test its grain refining performance.

FY 1998 report on the result of R and D projects by local consortiums. Rare metal recovery and resourcing of residual slags from metal plating wastes and aluminum dross by continuous thermit reaction (CTR) system; 1998 nendo CTR (Continuous Termit Reaction) System ni yoru aluminium dross to mekki surajji kara no energy less, rare metal kaisei process to sono slag no saishigenka seika hokokusho

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-03-01

The R and D project has been implemented for treating metal plating wastes (sludge) and aluminum dross in a melting furnace operated in a reducing atmosphere, in order to make the wastes harmless and recover the rare metals by the thermit reactions. The theoretical analysis of the powder properties has produced the desired powder pretreatment conditions, such as drying/firing conditions, mixing ratio and composition, forming conditions, and characteristics of the formed articles. For recovering the useful metals, it is confirmed that the thermit reactions proceed efficiently in a high-temperature melting furnace operated in a reducing atmosphere, and the molten metals are easily separated from the molten slag. It is also confirmed that the formed article allows separation of the metals from the residual slag more easily than the mixed powder. For the design of the continuous thermit reaction (CTR) system, it is investigated whether the products and other discharged substances can be safely handled and effectively utilized, and the control/instrumentation systems and others are established after setting the conditions for, e.g., sludge drying/firing in air, powder mixing/crushing, briquette production, and flow of the thermit reactions in a reducing atmosphere. (NEDO)

Mechanically activated SHS reaction in the Fe-Al system: in-situ time resolved diffraction using synchrotron radiation

International Nuclear Information System (INIS)

Gaffet, E.; Charlot, F.; Klein, D.; Bernard, F.; Niepce, J.C.

1998-01-01

The mechanical activation self propagating high temperature synthesis (M.A.S.H.S.) processing is a new way to produce nanocrystalline iron aluminide intermetallic compounds. This process is maily the combination of two steps; in the one hand, a mechanical activation where the Fe - Al powder mixture was milled during a short time at given energy and frequency of shocks and in the other hand, a self propagating high temperature synthesis (S.H.S.) reaction, for which the exothermicity of the Fe + Al reaction is used. This fast propagated MASHS reaction has been in-situ investigated using the time resolved X-ray diffraction (TRXRD) using a X-ray synchrotron beam and an infrared thermography camera, allowing the coupling of the materials structure and the temperature field. The effects of the initial mean compositions, of the milling conditions as well as of the compaction parameters on the MASHS reaction are reported. (orig.)

Propagation and diffusion-limited extinction of nonadiabatic heterogeneous flame in the SHS process

International Nuclear Information System (INIS)

Makino, Atsushi

1994-01-01

Nonadiabatic heterogeneous flame propagation and extinction in self-propagating high-temperature synthesis (SHS) are analyzed based on a premixed mode of propagation for the bulk flame supported by the nonpremixed reaction of dispersed nonmetals in the liquid metal. The formulation allows for volumetric heat loss throughout the bulk flame, finite-rate Arrhenius reaction at the particle surface, and temperature-sensitive Arrhenius mass diffusion in the liquid. Results show that, subsequent to melting of the metal, the flame structure consists of a relatively thin diffusion-consumption/convection zone followed by a relatively thick convection-loss zone, that the flame propagation rate decreases with increasing heat loss, that at a critical heat-loss rate the flame extinguishes as indicated by the characteristic turning-point behavior, that the surface reaction is diffusion limited such that the nonlinear, temperature-sensitive nature of the system is actually a consequence of the Arrhenius mass diffusion, and that extinction is sensitively affected by the mixture ratio, the degree of dilution, the initial temperature of the compact, and the size of the nonmetal particles. An explicit expression is derived for the normalized mass burning rate, which exhibits the characteristic turning point and shows that extinction occurs when this value is reduced to e -1/2 , which is the same as that for the nonadiabatic gaseous premixed flame. It is further shown that the theoretical results agree well with available experimental data, indicating that the present formulation captures the essential features of the nonadiabatic heterogeneous SHS processes and its potential for extension to describe other SHS phenomena

OpenSHS: Open Smart Home Simulator

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Nasser Alshammari

2017-05-01

Full Text Available This paper develops a new hybrid, open-source, cross-platform 3D smart home simulator, OpenSHS, for dataset generation. OpenSHS offers an opportunity for researchers in the field of the Internet of Things (IoT and machine learning to test and evaluate their models. Following a hybrid approach, OpenSHS combines advantages from both interactive and model-based approaches. This approach reduces the time and efforts required to generate simulated smart home datasets. We have designed a replication algorithm for extending and expanding a dataset. A small sample dataset produced, by OpenSHS, can be extended without affecting the logical order of the events. The replication provides a solution for generating large representative smart home datasets. We have built an extensible library of smart devices that facilitates the simulation of current and future smart home environments. Our tool divides the dataset generation process into three distinct phases: first design: the researcher designs the initial virtual environment by building the home, importing smart devices and creating contexts; second, simulation: the participant simulates his/her context-specific events; and third, aggregation: the researcher applies the replication algorithm to generate the final dataset. We conducted a study to assess the ease of use of our tool on the System Usability Scale (SUS.

OpenSHS: Open Smart Home Simulator.

Science.gov (United States)

Alshammari, Nasser; Alshammari, Talal; Sedky, Mohamed; Champion, Justin; Bauer, Carolin

2017-05-02

This paper develops a new hybrid, open-source, cross-platform 3D smart home simulator, OpenSHS, for dataset generation. OpenSHS offers an opportunity for researchers in the field of the Internet of Things (IoT) and machine learning to test and evaluate their models. Following a hybrid approach, OpenSHS combines advantages from both interactive and model-based approaches. This approach reduces the time and efforts required to generate simulated smart home datasets. We have designed a replication algorithm for extending and expanding a dataset. A small sample dataset produced, by OpenSHS, can be extended without affecting the logical order of the events. The replication provides a solution for generating large representative smart home datasets. We have built an extensible library of smart devices that facilitates the simulation of current and future smart home environments. Our tool divides the dataset generation process into three distinct phases: first design: the researcher designs the initial virtual environment by building the home, importing smart devices and creating contexts; second, simulation: the participant simulates his/her context-specific events; and third, aggregation: the researcher applies the replication algorithm to generate the final dataset. We conducted a study to assess the ease of use of our tool on the System Usability Scale (SUS).

Effect of Cr content on the SHS reaction of Cr-Ti-C system

International Nuclear Information System (INIS)

Zhang, W.N.; Wang, H.Y.; Wang, P.J.; Zhang, J.; He, L.; Jiang, Q.C.

2008-01-01

The effect of Cr content on the self-propagating high temperature synthesis (SHS) reaction of Cr-Ti-C system has been investigated in this research. The thermodynamics calculation indicates that the TiC possesses higher thermodynamic stability than the Cr 23 C 6 , Cr 7 C 3 and Cr 3 C 2 phases, and the formation of TiC is the most exothermic. Additionally, the adiabatic combustion temperature (T ad ) decreases with the increase of Cr content except for the phase transition regions. The XRD result shows that the type of products synthesized by SHS changes that a higher Cr content corresponds to higher chromium carbide. When Cr content is 10 wt.%, only solid solution (Ti,Cr)C ss is formed in the products. When Cr content increases to 20 wt.%, besides (Ti,Cr)C ss , the Cr 7 C 3 phase is also detected. With the Cr content further increasing to 30 and 40 wt.%, the products consist of (Ti,Cr)C ss , Cr 23 C 6 , Cr 7 C 3 and Cr, and therefore, much higher chromium carbide is synthesized. When Cr content reaches 50 wt.%, however, the Cr 7 C 3 disappears and the final products become (Ti,Cr)C ss , Cr 23 C 6 and Cr. Moreover, when Cr content increases from 10 to 20 wt.%, the lattice parameter of (Ti,Cr)C ss decreases, while it increases when the Cr content ranges from 20 to 50 wt.%. Furthermore, the microstructure shows that the TiC particulate size decreases from ∼8 to ∼2 μm with the increase of Cr content from 10 to 50 wt.%, and the morphology shape of TiC particulate becomes more and more spherical

Improving fatigue performance of rail thermite welds

Science.gov (United States)

Jezzini-Aouad, M.; Flahaut, P.; Hariri, S.; Winiar, L.

2010-06-01

Rail transport development offers economic and ecological interests. Nevertheless, it requires heavy investments in rolling material and infrastructure. To be competitive, this transportation means must rely on safe and reliable infrastructure, which requires optimization of all implemented techniques and structure. Rail thermite (or aluminothermic) welding is widely used within the railway industry for in-track welding during re-rail and defect replacement. The process provides numerous advantages against other welding technology commonly used. Obviously, future demands on train traffic are heavier axle loads, higher train speeds and increased traffic density. Thus, a new enhanced weld should be developed to prevent accidents due to fracture of welds and to lower maintenance costs. In order to improve such assembly process, a detailed metallurgical study coupled to a thermomechanical modelling of the phenomena involved in the thermite welding process is carried out. Obtained data enables us to develop a new improved thermite weld (type A). This joint is made by modifying the routinely specified procedure (type B) used in a railway rail by a standard gap alumino-thermic weld. Joints of type A and B are tested and compared. Based on experimental temperature measurements, a finite element analysis is used to calculate the thermal residual stresses induced. In the vicinity of the weld, the residual stress patterns depend on the thermal conditions during welding as it also shown by litterature [1, 2]. In parallel, X-Ray diffraction has been used to map the residual stress field that is generated in welded rail of types A and B. Their effect on fatigue crack growth in rail welds is studied. An experimental study based on fatigue tests of rails welded by conventional and improved processes adjudicates on the new advances and results will be shown.

Enrichment of W2B5 from WO3 and B2O3 by Double SHS Method

Directory of Open Access Journals (Sweden)

Bora DERIN

2018-02-01

Full Text Available A second self-propagating high-temperature synthesis (SHS was carried out to enrich the W2B5 content in the SHS product containing a mixture of various tungsten boride compounds. In the experiment, the process called Double-SHS (D-SHS was conducted in two steps. In the first SHS reaction, an initial molar composition ratio of WO3:B2O3:Mg mixture was selected as 1:3:8. The product was then hot-leached with hydrochloric acid to eliminate MgO and Mg3B2O6 phases. The leached product, consisting of 72.6 wt.% W2B5, 16.1 wt.% WB, 8.4 wt.% W2B, and 2.9 wt.% W, was again reacted with the Mg and B2O3 mixture by second SHS. After another acid leaching step, W2B5 content in the D-SHS product was found to be 98.2 wt.%. The study showed that D-SHS is an effective method for boron enrichment in the tungsten compounds.DOI: http://dx.doi.org/10.5755/j01.ms.24.1.17834

Chinese Pediatrician Attitudes and Practices Regarding Child Exposure to Secondhand Smoke (SHS and Clinical Efforts against SHS Exposure

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Kaiyong Huang

2015-05-01

Full Text Available Background: Secondhand Smoke (SHS exposure is a leading cause of childhood illness and premature death. Pediatricians play an important role in helping parents to quit smoking and reducing children’s SHS exposure. This study examined Chinese pediatricians’ attitudes and practices regarding children’s exposure to SHS and clinical efforts against SHS exposure. Methods: A cross-sectional survey of pediatricians was conducted in thirteen conveniently selected hospitals in southern China, during September to December 2013. Five hundred and four pediatricians completed self-administered questionnaires with a response rate of 92%. χ2 tests were used to compare categorical variables differences between smokers and non-smokers and other categorical variables. Results: Pediatricians thought that the key barriers to encouraging parents to quit smoking were: lack of professional training (94%, lack of time (84%, resistance to discussions about smoking (77%. 94% of the pediatricians agreed that smoking in enclosed public places should be prohibited and more than 70% agreed that smoking should not be allowed in any indoor places and in cars. Most of the pediatricians thought that their current knowledge on helping people to quit smoking and SHS exposure reduction counseling was insufficient. Conclusions: Many Chinese pediatricians did not have adequate knowledge about smoking and SHS, and many lacked confidence about giving cessation or SHS exposure reduction counseling to smoking parents. Lack of professional training and time were the most important barriers to help parents quit smoking among the Chinese pediatricians. Intensified efforts are called for to provide the necessary professional training and increase pediatricians’ participation in the training.

Chinese Pediatrician Attitudes and Practices Regarding Child Exposure to Secondhand Smoke (SHS) and Clinical Efforts against SHS Exposure

Science.gov (United States)

Huang, Kaiyong; Abdullah, Abu S.; Huo, Haiying; Liao, Jing; Yang, Li; Zhang, Zhiyong; Chen, Hailian; Nong, Guangmin; Winickoff, Jonathan P.

2015-01-01

Background: Secondhand Smoke (SHS) exposure is a leading cause of childhood illness and premature death. Pediatricians play an important role in helping parents to quit smoking and reducing children’s SHS exposure. This study examined Chinese pediatricians’ attitudes and practices regarding children’s exposure to SHS and clinical efforts against SHS exposure. Methods: A cross-sectional survey of pediatricians was conducted in thirteen conveniently selected hospitals in southern China, during September to December 2013. Five hundred and four pediatricians completed self-administered questionnaires with a response rate of 92%. χ2 tests were used to compare categorical variables differences between smokers and non-smokers and other categorical variables. Results: Pediatricians thought that the key barriers to encouraging parents to quit smoking were: lack of professional training (94%), lack of time (84%), resistance to discussions about smoking (77%). 94% of the pediatricians agreed that smoking in enclosed public places should be prohibited and more than 70% agreed that smoking should not be allowed in any indoor places and in cars. Most of the pediatricians thought that their current knowledge on helping people to quit smoking and SHS exposure reduction counseling was insufficient. Conclusions: Many Chinese pediatricians did not have adequate knowledge about smoking and SHS, and many lacked confidence about giving cessation or SHS exposure reduction counseling to smoking parents. Lack of professional training and time were the most important barriers to help parents quit smoking among the Chinese pediatricians. Intensified efforts are called for to provide the necessary professional training and increase pediatricians’ participation in the training. PMID:26006117

Obtención de Si3N4 mediante SHS

Directory of Open Access Journals (Sweden)

Rodríguez, M. A.

2003-04-01

Full Text Available In the present paper results obtained during synthesis of Silicon Nitride by Self-propagating High-temperature Synthesis (SHS are shown. Self-propagating High-temperature Synthesis is based on the high enthalpy of certain reactions able to be self-sustained. One of the most important advantages of the method is its very low energy consumption. The synthesis is carried out with a mixture of silicon powder with some additions of diluents and other synthesis aids (ammonium salts. The influence of the mixture composition on reaction parameters and characteristics of the obtained products has been studied. The use of new synthesis aids has been also studied in order to decrease the environmental impact of the process. Microstructural study, XRD and reaction parameters are shown. Finally a mechanism of Silicon Nitride synthesis is proposed.En el presente trabajo se presentan los resultados obtenidos en el estudio de las reacciones de Síntesis Autopropagada a Alta Temperatura (Self-propagating High-temperature Synthesis, SHS de Nitruro de Silicio. La síntesis autopropagada a alta temperatura consiste básicamente en la generación de reacciones altamente exotérmicas capaces de automantenerse. Se puede considerar como principal ventaja del método el ahorro energético que supone. La síntesis se realiza sobre una mezcla inicial de silicio metálico sobre la cual se realizan adiciones de diluyente y otros aditivos (sales amónicas que afectan al desarrollo de la reacción. Se ha estudiado la influencia que en este sistema pueden tener las proporciones de las distintas incorporaciones en la mezcla, tanto en el material resultante como en las condiciones de reacción. Igualmente se ha estudiado la posibilidad de utilización de nuevos aditivos que puedan minimizar el impacto medio ambiental. Se presentan los estudios microestructurales del material obtenido, la identificación cristalográfica de las fases presentes así como los comportamientos de los

Ignition dynamics and activation energies of metallic thermites: From nano- to micron-scale particulate composites

Science.gov (United States)

Hunt, Emily M.; Pantoya, Michelle L.

2005-08-01

Ignition behaviors associated with nano- and micron-scale particulate composite thermites were studied experimentally and modeled theoretically. The experimental analysis utilized a CO2 laser ignition apparatus to ignite the front surface of compacted nickel (Ni) and aluminum (Al) pellets at varying heating rates. Ignition delay time and ignition temperature as a function of both Ni and Al particle size were measured using high-speed imaging and microthermocouples. The apparent activation energy was determined from this data using a Kissinger isoconversion method. This study shows that the activation energy is significantly lower for nano- compared with micron-scale particulate media (i.e., as low as 17.4 compared with 162.5kJ /mol, respectively). Two separate Arrhenius-type mathematical models were developed that describe ignition in the nano- and the micron-composite thermites. The micron-composite model is based on a heat balance while the nanocomposite model incorporates the energy of phase transformation in the alumina shell theorized to be an initiating step in the solid-solid diffusion reaction and uniquely appreciable in nanoparticle media. These models were found to describe the ignition of the Ni /Al alloy for a wide range of heating rates.

THERMAL STABILITY OF Al-Cu-Fe QUASICRYSTALS PREPARED BY SHS METHOD

OpenAIRE

Pavel Novák; Alena Michalcová; Milena Voděrová; Ivo Marek; Dalibor Vojtěch

2013-01-01

Quasicrystal-containing materials are usually prepared by rapid solidification of the melt (e.g. by melt spinning) or mechanical alloying. In this work, the method using exothermic reactions between compressed metallic powders called SHS (Self-propagating High-temperature Synthesis) was tested. The microstructure and phase composition of the product was described in dependence on cooling regime from the reaction temperature. Thermal stability of prepared Al-Cu-Fe quasicrystals was studied by...

SHS synthesis of Si-SiC composite powders using Mg and reactants from industrial waste

Science.gov (United States)

Chanadee, Tawat

2017-11-01

Si-SiC composite powders were synthesized by self-propagating high-temperature synthesis (SHS) using reactants of fly ash-based silica, sawdust-based activated carbon, and magnesium. Fly ash-based silica and sawdust-based activated carbon were prepared from coal mining fly ash and Para rubber-wood sawdust, respectively. The work investigated the effects of the synthesis atmosphere (air and Ar) on the phase and morphology of the SHS products. The SHS product was leached by a two-step acid leaching processes, to obtain the Si-SiC composite powder. The SHS product and SHS product after leaching were characterized by X-ray diffractometry, scanning electron microscopy and energy dispersive X-ray spectrometry. The results indicated that the SHS product synthesized in air consisted of Si, SiC, MgO, and intermediate phases (SiO2, Mg, Mg2SiO4, Mg2Si), whereas the SHS product synthesized in Ar consisted of Si, SiC, MgO and a little Mg2SiO4. The SiC content in the leached-SHS product was higher when Ar was used as the synthesis atmosphere. As well as affecting the purity, the synthesis atmospheres also affected the average crystalline sizes of the products. The crystalline size of the product synthesized in Ar was smaller than that of the product synthesized in air. All of the results showed that fly ash and sawdust could be effective waste-material reactants for the synthesis of Si-SiC composite powders.

A survey of combustible metals, thermites, and intermetallics for pyrotechnic applications

Energy Technology Data Exchange (ETDEWEB)

Fischer, S.H.; Grubelich, M.C.

1996-08-01

Thermite mixtures, intermetallic reactants, and metal fuels have long been used in pyrotechnics. Advantages include high energy density, impact insensitivity, high combustion temperature, and a wide range of gas production. They generally exhibit high temperature stability and possess insensitive ignition properties. This paper reviews the applications, benefits, and characteristics of thermite mixtures, intermetallic reactants, and metal fuels. 50 refs, tables.

Research on manufacturing aluminum - rare earth alloy with a high content of rare earth (> 20% RE) from total rare earth oxides by thermit reduction

International Nuclear Information System (INIS)

Ngo Trong Hiep; Dam Van Tien; Tran Duy Hai; Ngo Xuan Hung and Ly Thanh Vu

2004-01-01

In this report, several theoretical principles of thermit reduction method used for metal oxides to obtain metals, ferroalloys and ligatua with technical purity are presented. Manufacture of aluminum-rare earth alloys by thermit reduction is also described in the report. Data that are generalized based on thermo-kinetic calculation of the thermit reduction and selection of technological flow-sheet based on thermal effect will partly clarify research results in investigating typical features of the process and identify measures to reduce metal loss in discharged slags. (author)

Burning velocity of the heterogeneous flame propagation in the SHS process expressed in explicit form

International Nuclear Information System (INIS)

Makino, A.; Law, C.K.

1995-01-01

The combustion behavior of the self-propagating high-temperature synthesis (SHS) process has been the subject of many analytical and experimental investigations. Recently, a theory based on spray combustion was proposed for the SHS flame structure and propagation. In contrast to previous studies based on the homogeneous premixed flame, this theory accounts for the premixed-mode of propagation of the bulk flame and the non-premixed reaction of the dispersed nonmetal (or higher melting-point metal) particles which supports the bulk flame. Finite-rate reaction at the particle surface and the temperature-dependent, Arrhenius nature of mass diffusion are both incorporated. The heterogeneous nature of the theory has satisfactorily captured the effects of particle size on the flame propagation speed. The final solution of Makino and Law was obtained numerically and hence presented parametrically. The authors have since then derived an approximate analytical expression for the burning velocity, which explicitly displays the functional dependence of the burning velocity on the various system parameters. This result is presented herein. Applicability of this expression is examined by comparing it with the numerical results for Ti-C, Ti-B, Zr-B, Hf-B, and Co-Ti systems. A fair degree of agreement has been shown as far as the general trend and approximate magnitude are concerned

Stabilized super-thermite colloids: A new generation of advanced highly energetic materials

Science.gov (United States)

Elbasuney, Sherif; Gaber Zaky, M.; Radwan, Mostafa; Mostafa, Sherif F.

2017-10-01

One of the great impetus of nanotechnology on energetic materials is the achievement of nanothermites (metal-oxide/metal) which are characterized by massive heat output. Yet, full exploitation of super-thermites in highly energetic systems has not been achieved. This manuscript reports on the sustainable fabrication of colloidal Fe2O3 and CuO nanoparticles for thermite applications. TEM micrographs demonstrated mono-dispersed Fe2O3 and CuO with an average particle size of 3 and 15 nm respectively. XRD diffractograms demonstrated highly crystalline materials. SEM micrographs demonstrated a great tendency of the developed oxides to aggregate over drying process. The effective integration and dispersion of mono-dispersed colloidal thermite particles into energetic systems are vital for enhanced performance. Aluminum is of interest as highly energetic metal fuel. In this paper, synthesized Fe2O3 and CuO nanoparticles were re-dispersed in isopropyl alcohol (IPA) with aluminum nanoparticles using ultrasonic prope homogenizer. The colloidal thermite peraticles can be intgegrated into highly energetic system for subsequent nanocomposite development. Thanks to stabilization of colloidal CuO nanoparticles in IPA which could offer intimate mixing between oxidizer and metal fuel. The stabilization mechanism of CuO in IPA was correlated to steric stabilization with solvent molecules. This approach eliminated nanoparticle drying and the re-dispersion of dry aggregates into energetic materials. This manuscript shaded the light on the real development of colloidal thermite mixtures and their integration into highly energetic systems.

Thermal stability of Al-Cu-Fe quasicrystals prepared by SHS method

Directory of Open Access Journals (Sweden)

Pavel Novak

2013-02-01

Full Text Available Quasicrystal-containing materials are usually prepared by rapid solidification of the melt (e.g. by melt spinning or mechanical alloying. In this work, the method using exothermic reactions between compressed metallic powders called SHS (Self-propagating High-temperature Synthesis was tested. The microstructure and phase composition of the product was described in dependence on cooling regime from the reaction temperature. Thermal stability of prepared Al-Cu-Fe quasicrystals was studied by annealing at the temperatures of 300 and 500 °C.

THERMAL STABILITY OF Al-Cu-Fe QUASICRYSTALS PREPARED BY SHS METHOD

Directory of Open Access Journals (Sweden)

Pavel Novák

2013-04-01

Full Text Available Quasicrystal-containing materials are usually prepared by rapid solidification of the melt (e.g. by melt spinning or mechanical alloying. In this work, the method using exothermic reactions between compressed metallic powders called SHS (Self-propagating High-temperature Synthesis was tested. The microstructure and phase composition of the product was described in dependence on cooling regime from the reaction temperature. Thermal stability of prepared Al-Cu-Fe quasicrystals was studied by annealing at the temperatures of 300 and 500 °C.

Simulation of TRAN B experiments by alumina thermite melt injection (SIMBATH out-of-pile experiments, TRAN simulation B1/1, B1/3, B1/4)

International Nuclear Information System (INIS)

Peppler, W.; Will, H.

1986-07-01

The SIMBATH programme was initiated to investigate the physical phenomena of transient material movement and relocation during transient overpower (TOP) and loss of flow (LOF) driven TOP accidents in LMFBR's. The energy release during the accident is simulated out of pile by the reaction of a thermite mixture. Within the frame of comparing studies of the behaviour of fuel (UO 2 ) and the thermite melt (Al 2 O 3 +Fe) used, respectively, the TRAN B series was reproduced out of pile with this thermite. Special emphasis is given to the similarities and differences in the freezing behaviour of these two materials. The test results of the simulation experiments are analysed and reported. Additionally the tests were recalculated with the code PLUGM. Similarity is found with respect to the freezing behaviour of these two materials. (orig.) [de

Fabrication of Ni-Al/diamond composite based on layered and gradient structures of SHS system

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Lu Jiafeng

2017-01-01

Full Text Available In this paper layered and gradient structures of Ni-Al SHS system were adopted to manufacture Ni-Al/diamond composites. The effect of the layered and the diamond mesh gradient structures of Ni-Al/diamond on the SHS process and the microstructure of the composites were investigated. It is found that with the increasing of the number of layers, the combustion wave velocity is decreased. The combustion wave velocity for diamond mesh size gradient structure of Ni-Al SHS is faster than that for the layered structure. A well bonding can be formed between diamond and the matrix in layered and gradient structure Ni-Al/diamond composites due to the melt of Ni-Cr brazing alloy.

Smoke-free policies and non-smokers’ reactions to SHS exposure in small and medium enterprises

Directory of Open Access Journals (Sweden)

Calliopi Sivri

2013-12-01

Full Text Available Introduction: Non-smoker employees can significantly improve the existing smoke-free policies in the workplace by asserting their right for smoke-free air and confronting smoker colleagues. The aim of the study was to assess the psychological and social drivers of non-smokers' readiness to assert their right for smoke-free air in the workplace. Materials and Methods: Twenty-six small-and-medium enterprises (SME with diverse background were randomly selected, and 284 employees agreed to participate in the study. Our study focused on the responses of 85 non-smokers (M age = 34 years, SD = 7.98, 84.2% worked in indoor offices. A cross-sectional design was used and participants completed a structured anonymous questionnaire assessing background and demographic characteristics, and psychosocial predictors of assertiveness intentions. Results: Although more than half of non-smokers reported they were often/almost always bothered by exposure to SHS, roughly one third of them reported having asked their colleagues not to smoke at work. Regression analysis showed that the effects of distal predictors (i.e. annoyance due to SHS exposure were mediated by past behaviour, attitudes (protection motivation beliefs, social norms, and self-efficacy. Conclusions: Health beliefs related to SHS exposure, and concerns about workplace health and job performance, social norms and self-efficacy can increase the assertiveness of non-smokers in workplace settings. Related campaigns should focus on communicating normative messages and self-efficacy training to empower non-smoker employees to act assertively towards protecting their smoke-free rights.

Preparation and Characterization of Amorphous B Powders by Salt-Assisted SHS Technique

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Yujing Ou

2015-01-01

Full Text Available To use the salt-assisted SHS technique to prepare B powders was proposed. Calculation results found that the adiabatic combustion temperature of the B2O3-Mg reaction system was 2604 K, higher than the 1800 K criterion of self-propagating temperature, which meant that the SHS application was feasible. When 0, 10%, 20%, 30%, 40%, 50%, and 60% NaCl content were added, the adiabatic combustion temperature of the reaction system decreased linearly. When 60% NaCl content was added, the adiabatic combustion temperature was 1799 K (lower than 1800 K, unsuitable for self-propagating reaction, which was consistent with the experimental results. Through scanning electron microscope (SEM, energy disperse spectroscopy (EDS, and particle size analysis, the influence of different addition of NaCl on the morphology, average particle size, and purity of prepared B powder was investigated. EDS and chemical analysis indicated that the purity of prepared B powder was over 96% and the average particle size was within the range of 0.4~0.8 μm when the content of NaCl was 50%. The analysis of X-ray diffraction (XRD and selected area electron diffraction (SAED proved that the prepared B powder was amorphous.

An Investigation of Porous Structure of TiNi-Based SHS-Materials Produced at Different Initial Synthesis Temperatures

Science.gov (United States)

Khodorenko, V. N.; Anikeev, S. G.; Kokorev, O. V.; Yasenchuk, Yu. F.; Gunther, V. É.

2018-02-01

An investigation of structural characteristics and behavior of TiNi-based pore-permeable materials manufactured by the methods of selfpropagating high-temperature synthesis (SHS) at the initial synthesis temperatures T = 400 and 600°C is performed. It is shown that depending on the temperature regime, the resulting structure and properties of the material can differ. It is found out that the SHS-material produced at the initial synthesis temperature T = 400°C possesses the largest number of micropores in the pore wall surface structure due to a high phase inhomogeneity of the alloy. The regime of structure optimization of the resulting materials is described and the main stages of formation of the pore wall microporous surfaces are revealed. It is demonstrated that after optimization of the surface structure of a TiNi-based fine-pore alloy by its chemical etching, the fraction of micropores measuring in size less than 50 nm increased from 59 to 68%, while the number of pores larger than 1 μm increased twofold from 11 to 22%. In addition, peculiar features of interaction between certain cell cultures with the surface of the SHS-material manufactured at different initial synthesis temperatures are revealed. It is found out that the dynamics of the cell material integration depends on the pore wall surface morphology and dimensions of macropores.

Synchrotron diffraction studies of TiC/FeTi cermets obtained by SHS

International Nuclear Information System (INIS)

Contreras, L.; Turrillas, X.; Mas-Guindal, M.J.; Vaughan, G.B.M.; Kvick, A.; Rodriguez, M.A.

2005-01-01

TiC/FeTi composites have been obtained in situ by Self-propagating High-temperature Synthesis (SHS) of an intimate mixture of compacted powders of elemental carbon, titanium and iron. The reaction has been followed in real time by X-ray diffraction at the ESRF. The mechanism of the reaction is discussed in terms of the formation of a liquid phase corresponding to the eutectic of the Fe/Ti system prior to the TiC synthesis. Temperatures of reaction have been estimated by correlating thermal expansion coefficients with diffraction peaks shifts. The microstructures obtained by this method, suitable for cutting tools and wear resistant applications, are presented

Solar Home System (SHS) in rural Bangladesh: Ornamentation or fact of development?

International Nuclear Information System (INIS)

Rahman, Syed M.; Ahmad, Mokbul M.

2013-01-01

Energy requirement has been growing every day due to higher population growth, and consequently higher consumption. About one third of rural households of Bangladesh are connected to the grid. To meet the gap, solar energy has been treated as a feasible option for people in rural areas where grid connections are not available. A good number of organizations have been working together to provide Solar Home System (SHS) in rural Bangladesh. There is little evidence that supply of small scale energy supports significant rural development. This paper aims at understanding how increased energy access through SHS in rural Bangladesh contributes towards rural development. Recent published literatures on SHS in Bangladesh have been studied to get insight into the technical, financial, and operational as well as economic and social issues. Later the findings have been critically analyzed with respect to selected indicators of rural development. The study identified that increased access to energy through SHS in rural Bangladesh provides mostly recreational and leisure benefits with the so called ‘social status’; income generation is negligible while support for education is average. - Highlights: • No specific proof is there to conclude that SHS has contributed to development. • SHS's contribution to income generation and employment is not significant. • SHS is mostly used for entertainment and to uplift the so called ‘social status’

Immobilization of simulated radioactive soil waste containing cerium by self-propagating high-temperature synthesis

International Nuclear Information System (INIS)

Mao, Xianhe; Qin, Zhigui; Yuan, Xiaoning; Wang, Chunming; Cai, Xinan; Zhao, Weixia; Zhao, Kang; Yang, Ping; Fan, Xiaoling

2013-01-01

A simulated radioactive soil waste containing cerium as an imitator element has been immobilized by a thermite self-propagating high-temperature synthesis (SHS) process. The compositions, structures, and element leaching rates of products with different cerium contents have been characterized. To investigate the influence of iron on the chemical stability of the immobilized products, leaching tests of samples with different iron contents with different leaching solutions were carried out. The results showed that the imitator element cerium mainly forms the crystalline phases CeAl 11 O 18 and Ce 2 SiO 5 . The leaching rate of cerium over a period of 28 days was 10 −5 –10 −6 g/(m 2 day). Iron in the reactants, the reaction products, and the environment has no significant effect on the chemical stability of the immobilized SHS products

Immobilization of simulated radioactive soil waste containing cerium by self-propagating high-temperature synthesis

Science.gov (United States)

Mao, Xianhe; Qin, Zhigui; Yuan, Xiaoning; Wang, Chunming; Cai, Xinan; Zhao, Weixia; Zhao, Kang; Yang, Ping; Fan, Xiaoling

2013-11-01

A simulated radioactive soil waste containing cerium as an imitator element has been immobilized by a thermite self-propagating high-temperature synthesis (SHS) process. The compositions, structures, and element leaching rates of products with different cerium contents have been characterized. To investigate the influence of iron on the chemical stability of the immobilized products, leaching tests of samples with different iron contents with different leaching solutions were carried out. The results showed that the imitator element cerium mainly forms the crystalline phases CeAl11O18 and Ce2SiO5. The leaching rate of cerium over a period of 28 days was 10-5-10-6 g/(m2 day). Iron in the reactants, the reaction products, and the environment has no significant effect on the chemical stability of the immobilized SHS products.

The impact of SHS exposure on health status and exacerbations among patients with COPD

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Mark D Eisner

2009-05-01

hospital-based care for COPD, which was a composite endpoint of either ED visits or hospitalizations for COPD (HR 1.52; 95% CI 1.06 to 2.18 and HR 1.40; 95% CI 0.94 to 2.10, respectively. In conclusion, SHS was associated with poorer health status and a greater risk of COPD exacerbation. COPD patients may comprise a vulnerable population for the health effects of SHS.Keywords: chronic obstructive pulmonary disease, chronic bronchitis, pulmonary emphysema, tobacco smoke pollution

Are micro-benefits negligible? The implications of the rapid expansion of Solar Home Systems (SHS) in rural Bangladesh for sustainable development

Energy Technology Data Exchange (ETDEWEB)

Komatsu, Satoru, E-mail: skomatsu@hiroshima-u.ac.jp [Graduate School for International Development and Cooperation, Hiroshima University, 1-5-1 Kagamiyama, Higashi-hiroshima, Hiroshima 739-8529 (Japan); Kaneko, Shinji, E-mail: kshinji@hiroshima-u.ac.jp [Graduate School for International Development and Cooperation, Hiroshima University, 1-5-1 Kagamiyama, Higashi-hiroshima, Hiroshima 739-8529 (Japan); Ghosh, Partha Pratim, E-mail: partha1975@gmail.com [Arc Bangladesh (Bangladesh)

2011-07-15

This paper examines the multiple benefits of the adoption of Solar Home Systems (SHS) and discusses the dissemination potential for sustainable rural livelihoods in developing countries. Based on a household survey conducted in rural Bangladesh, we first identify the impact of SHS on the reduction in energy costs and compare purchasing costs. We then examine household lifestyle changes following the adoption of SHS. Finally, we consider several price-reduction scenarios to examine the potential demand for SHS and to evaluate its future dissemination potential. The results of the analysis indicate that households with SHS successfully reduce their consumption of kerosene and dependency on rechargeable batteries, with the cost reductions accounting for some 20-30% of monthly expenditures on SHS. Moreover, most households with SHS can enjoy its benefits, including electric lighting, watching television, and the ease of mobile phone recharging at home. Further, the price reduction can make possible potential demand in more than 60% of households without SHS, while additional price reductions promote the purchase of even larger SHS packages. This study concludes that even though the scale of single SHS is small, the micro-benefits for each household and the dissemination potential are substantial. - Research Highlights: > Price reductions on Solar Home Systems potentially generate demand. > Solar Home Systems enable a reduction in energy costs and improvements in lifestyle. > The micro-benefits for households and the dissemination potential are substantial.

Prompt striations observed in a barium thermite release at 335 km

International Nuclear Information System (INIS)

Simons, D.J.; Pongratz, M.B.; Smith, G.M.; Barasch, G.E.; Fitzgerald, T.J.

1981-01-01

Three barium clouds have been released from a single rocket at altitudes of 335, 443, and 535 km. The releases were by means of barium thermite injection. Adding the different cross-field velocity components of the rocket at each of the releases resulted in barium clouds with different kinetic velocity distributions. The barium cloud with the most peaked velocity distribution striated promptly, in good agreement with theoretical predictions based on a kinetic plasma instability. Details of the data analysis and experiment are discussed

Are micro-benefits negligible? The implications of the rapid expansion of Solar Home Systems (SHS) in rural Bangladesh for sustainable development

International Nuclear Information System (INIS)

Komatsu, Satoru; Kaneko, Shinji; Ghosh, Partha Pratim

2011-01-01

This paper examines the multiple benefits of the adoption of Solar Home Systems (SHS) and discusses the dissemination potential for sustainable rural livelihoods in developing countries. Based on a household survey conducted in rural Bangladesh, we first identify the impact of SHS on the reduction in energy costs and compare purchasing costs. We then examine household lifestyle changes following the adoption of SHS. Finally, we consider several price-reduction scenarios to examine the potential demand for SHS and to evaluate its future dissemination potential. The results of the analysis indicate that households with SHS successfully reduce their consumption of kerosene and dependency on rechargeable batteries, with the cost reductions accounting for some 20-30% of monthly expenditures on SHS. Moreover, most households with SHS can enjoy its benefits, including electric lighting, watching television, and the ease of mobile phone recharging at home. Further, the price reduction can make possible potential demand in more than 60% of households without SHS, while additional price reductions promote the purchase of even larger SHS packages. This study concludes that even though the scale of single SHS is small, the micro-benefits for each household and the dissemination potential are substantial. - Research Highlights: → Price reductions on Solar Home Systems potentially generate demand. → Solar Home Systems enable a reduction in energy costs and improvements in lifestyle. → The micro-benefits for households and the dissemination potential are substantial.

In situ synthesis of TiB2-TiC particulates locally reinforced medium carbon steel-matrix composites via the SHS reaction of Ni-Ti-B4C system during casting

International Nuclear Information System (INIS)

Wang, H.Y.; Huang, L.; Jiang, Q.C.

2005-01-01

The fabrication of medium carbon steel-matrix composites locally reinforced with in situ TiB 2 -TiC particulates using self-propagating high-temperature synthesis (SHS) reaction of Ni-Ti-B 4 C system during casting was investigated. X-ray diffraction (XRD) results reveal that the exotherm of 1042 deg. C initiated by heat release of the solid state reaction in the differential thermal analysis (DTA) curve is an incomplete reaction in Ni-Ti-B 4 C system. As-cast microstructures of the in situ processed composites reveal a relatively uniform distribution of TiB 2 -TiC particulates in the locally reinforced regions. Furthermore, the particulate size and micro-porosity in the locally reinforced regions are significantly decreased with the increasing of the Ni content in the preforms. For a Ni content of 30 and 40 wt.%, near fully dense composites locally reinforced with in situ TiB 2 and TiC particulates can be fabricated. Although most of fine TiB 2 and TiC particulates which form by the reaction-precipitation mechanism during SHS reaction are present in the locally reinforced region, some large particulates which form by the nucleation-growth mechanism during solidification are entrapped inside the Fe-rich region located in the reinforcing region or inside the matrix region nearby the interface between matrix and reinforcing region. The hardness of the reinforcing region in the composite is significantly higher than that of the unreinforced medium carbon steel. Furthermore, the hardness values of the composites synthesized from 30 to 40 wt.% Ni-Ti-B 4 C systems are higher than those of the composites synthesized from 10 to 20 wt.% Ni-Ti-B 4 C systems

Correlates of exposure to secondhand smoke (SHS) at home among non-smoking adults in Bangladesh: findings from the ITC Bangladesh survey.

Science.gov (United States)

Abdullah, Abu S; Driezen, Pete; Sansone, Genevieve; Nargis, Nigar; Hussain, Ghulam Akm; Quah, Anne Ck; Fong, Geoffrey T

2014-07-16

Exposure to secondhand smoke (SHS) is a serious global public health problem. Understanding the correlates of SHS exposure could guide the development of evidence based SHS exposure reduction interventions. The purpose of this study is to describe the pattern of and factors associated with SHS exposure among non-smoking adults in Bangladesh. Data come from adult non-smokers who participated in the second wave (2010) of the International Tobacco Control Policy (ITC) Evaluation Bangladesh Survey conducted in all six administrative divisions of Bangladesh. A structured questionnaire gathered information on participants' demographic characteristics, pattern of SHS exposure, SHS knowledge, and attitudes towards tobacco control. Exposure to SHS at home was defined as non-smokers who lived with at least one smoker in their household and who reported having no home smoking ban. The data were analyzed using chi-square tests and logistic regression procedures. The SHS exposure rate at home among the participants (N=2813) was 43%. Several sociodemographic and attitudinal factors were associated with SHS exposure. Logistic regression analyses identified eight predictors of SHS exposure: being female (OR=2.35), being aged 15-24 (OR=2.17), being recruited from Dhaka slums (OR=5.19) or non-tribal/non-border areas outside Dhaka (OR=2.19) or tribal/border area (OR=4.36), having lower education (1-8 years: OR=2.45; illiterate: OR=3.00, having higher monthly household income (5000 to non-smoking Bangladeshi adults are exposed to SHS at home. The findings suggest the need for comprehensive tobacco control measures that would improve public understanding about health hazards of SHS exposure at home and encourage educational initiatives to promote smoke-free homes. Interventions should deliver targeted messages to reach those in the low socioeconomic status group.

JournalBase. Comparer les bases de données scientifiques internationales en sciences humaines et sociales (SHS

Directory of Open Access Journals (Sweden)

Denise Pumain

2010-01-01

Full Text Available Cet article dresse un tableau comparatif des contenus des bases de données et des listes de référence qui recensent les revues en sciences humaines et sociales (SHS. Il s’appuie sur JournalBase publié le 25 juin 2009 dans Cybergeo. Cette étude porte sur les bases AHCI et SSCI du Web of Science (publié par Thomson Reuters, de Scopus (publié par Elsevier, du European Reference Index for Humanities (ERIH (publié par la Fondation européenne pour la Science et de l’AERES (Agence pour l’évaluation de la recherche en France. La recherche a été réalisée en 2008 avec le soutien financier du TGE Adonis du CNRS. Avec quelque 20 000 entrées correspondant à environ 10 000 journaux différents, c’est une vue quasi exhaustive de la richesse des publications en sciences humaines et sociales qui est apportée par ce tableau. La nomenclature adoptée pour classer les revues par discipline est celle en 27 postes de la Fondation Européenne pour la Science. Les affectations multiples révèlent la multidisciplinarité des revues, assez fréquente en SHS, mais parfois aussi les incohérences des bases de données qui n’ont pas été rectifiées.L’article présente l’historique du projet, la méthodologie mise en place par les auteurs, les difficultés rencontrées dans la comparaison des données. Les premiers résultats mettent en évidence une couverture plus large de la liste ERIH pour les sciences humaines et une surreprésentation des revues anglophones dans les bases de données commerciales pour l’ensemble des disciplines. L’objectif de ce travail est d’alerter sur les contenus de ces bases de données, au moment où les outils bibliométriques soulèvent maints débats quant à leur application dans le champ des sciences humaines et sociales.

The TackSHS project - a collaborative H2020 project

Directory of Open Access Journals (Sweden)

Esteve Fernandez

2016-03-01

Full Text Available TackSHS is a new research project funded by the European Union’s Horizon 2020 Research and Innovation Programme. It aims to improve our understanding of second-hand tobacco smoke and e-cigarette emissions and find ways of tackling the health burden caused by exposure to them. Within a fast changing environment, the project will try to elucidate the comprehensive impact that SHS and e-cigarette aerosols have on respiratory health of the European population and how health impacts vary according to socio-economic parameters with particular emphasis on specific vulnerable groups such as patients suffering from chronic lung diseases.

Cardiorespiratory response to exercise of nonsmokers occupationally exposed to second hand smoke (SHS

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Anastasios Mantzoros

2017-01-01

Chronic occupational SHS exposure among non-smokers deteriorates CR exercise performance increasing risk of developing SHS associated diseases. Smoking ban legislation should be enforced but also inclusive of all workplaces eliminating the existing violation of labor and human rights.

On immobilization of high-level waste in an Y–Al garnet-based cermet matrix in SHS conditions

OpenAIRE

Konovalov, E.E.; Lastov, A.I.; Nerozin, N.A.

2015-01-01

A method of high-level waste (HLW) radionuclide immobilization in a long-life matrix based on Y–Al garnet, a material highly chemically resistant to natural environments, has been developed for the ultimate HLW isolation from the environment. Model systems containing Ce, Nd, Sm, Zr, Mo, 238U, and 241Am were used in the study as simulators of HLW radionuclides. An energy-saving technology of self-propagating high-temperature synthesis (SHS) was employed to synthesize the matrix material with f...

XRD, SEM and infrared study into the intercalation of sodium hexadecyl sulfate (SHS) into hydrocalumite.

Science.gov (United States)

Zhang, Ping; Wang, Tianqi; Zhang, Longlong; Wu, Daishe; Frost, Ray L

2015-12-05

Hydrocalumite (CaAl-LDH-Cl) interacted with a natural anionic surfactant, sodium hexadecyl sulfate (SHS), was performed using an intercalation method. To understand the intercalation behavior and characterize the resulting products, powder X-ray diffraction (XRD), scan electron microscopy (SEM) and mid-infrared (MIR) spectroscopy combined with near-infrared (NIR) spectroscopy technique were used. The XRD analysis indicated that SHS was intercalated into CaAl-LDH-Cl successfully, resulting in an expansion of the interlayer (from 0.78 nm to 2.74 nm). The bands of C-H stretching vibrations of SHS were observed in the near-infrared spectra, which indicated that the resulting products were indeed CaAl-LDH-SHS. In addition, the bands of water stretching vibrations and OH groups shifted to higher wavenumbers when SHS was intercalated into CaAl-LDH-Cl interlayer space. Copyright © 2015 Elsevier B.V. All rights reserved.

Statistika i karakter spoljne trgovine Kraljevine SHS 1919-1929.

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Ivan M. Becić

2015-08-01

Full Text Available Active trade balance was one of the most important factors of financial policy of the Kingdom of Serbs Croats and Slovenes. It was supposed to contribute to the stability of the domestic currency. This intention could not be achived until 1924 since the recovery of the economy of the Kingdom from the great casualties and material hardship in the First World War. In following years, the foreign trade balance was active, except in exceptional drought years of 1927 and 1928. The main items of export were agricultural products alongside with raw materials and semi-finished products. On the other hand, the main items of imports were manufactured goods, materials for the textile industry, different machinery and tools. Great importance for the import into the Kingdom of SHS were on its neighbours. In 1929 they accounted around 38.2% of import, while as the destination of the Yugoslav exports were absolutely dominant with 69.16%. The discrepancy between foreign trade and foreign policy of the Kingdom of SHS was obvious. Although the main Yugoslav ally at the time, France has participated in trade with only a few percent. It was similar practice with another Great War ally: Great Britain. Wider economic relations with Czechoslovakia were hindered by lack of Czech interest to purchase goods from the Kingdom of SHS. On the other hand, the most important partners were Italy, which showed huge belligerence against new Yugoslavian state, and have a strained political relations with Kingdom of SHS throughout the 1920s and Austria and Germany, both bitter enemies form the First World War.

JournalBase - Une étude comparative internationale des bases de données des revues scientifiques en sciences humaines et sociales (SHS

Directory of Open Access Journals (Sweden)

Christine Kosmopoulos

2009-06-01

Full Text Available Pour la première fois en 2009 ont été ici présentés dans un tableau comparatif les contenus des bases de données qui recensent les revues en sciences humaines et sociales (SHS, du Web of Science (publié par Thomson Reuters et de Scopus (publié par Elsevier ainsi que des listes de référence European Reference Index for Humanities (ERIH (publiée par la Fondation européenne pour la Science et de l'AERES. Avec quelque 20 000 entrées, c’est une vue quasi exhaustive de la richesse des publications en sciences humaines et sociales qui est enfin apportée par ce tableau. La nomenclature adoptée pour classer les revues par discipline est celle en 27 postes de la Fondation Européenne pour la Science. Les affectations multiples révèlent la multidisciplinarité des revues, assez fréquente en SHS, mais parfois aussi les incohérences des bases de données qui n’ont pas été rectifiées.La recherche a été réalisée en 2008 avec le soutien financier du TGE Adonis du CNRS.Une mise à jour prochaine sera proposée en ligne.L’objectif final de ce projet, qui concerne l'ensemble de la communauté internationale en SHS, était de mettre en ligne, en version bilingue anglais/français, la base de données de JournalBase en mode interactif sur une plate-forme collaborative ainsi que le rapport final de l’étude, afin que les décideurs, les scientifiques, les experts de l'information scientifique disposent d’informations à jour et qu’ils puissent contribuer à faire avancer la réflexion sur ces questions, par l’échange d’expériences et de bonnes pratiques d’utilisation.Un article présentant l'historique du projet, la méthodologie mise en place et les difficultés rencontrées dans la comparaison des données a été publié le 8 janvier 2010. Il analyse également les premiers résultats.Désormais vous pouvez accéder à l'information intégrale de JournalBase sur le site : http://journalbase.cnrs.fr

Fabrication of intermetallic NiAl by self-propagating high-temperature synthesis reaction using aluminium nanopowder under high pressure

CERN Document Server

Dong Shu Shan; Cheng Hai Yong; Yang Hai Bin; Zou Guang Tian

2002-01-01

By using aluminium nanopowder prepared by wire electrical explosion, pure monophase NiAl compound with fine crystallites (<=10 mu m) and good densification (98% of the theoretical green density) was successfully fabricated by means of self-propagating high-temperature synthesis (SHS) under a high pressure of 50 MPa. Investigation shows that, due to the physical and chemical characteristics of the nanoparticles, the SHS reaction mode and mechanism are distinct from those when using conventional coarse-grained reactants. The SHS reaction process depends on the thermal conditions related to pressure and can occur at a dramatically low temperature of 308 sup o C, which cannot be expected in conventional SHS reaction. With increasing pressure, the SHS explosive ignition temperature (T sub i sub g) of forming NiAl decreases due to thermal and kinetic effects.

The Effect of a Pilot Pediatric In-Patient Department-Based Smoking Cessation Intervention on Parental Smoking and Children's Secondhand Smoke (SHS) Exposure in Guangxi, China.

Science.gov (United States)

Huang, Kaiyong; Yang, Li; Winickoff, Jonathan P; Liao, Jing; Nong, Guangmin; Zhang, Zhiyong; Liang, Xia; Liang, Gang; Abdullah, Abu S

2016-11-08

Children's exposure to secondhand smoke (SHS) at home has numerous adverse health effects. This study evaluated the effects of a pediatric in-patient department-based pilot smoking cessation intervention for household members to reduce children's SHS exposure and encourage smoking cessation. A pre-post test design study was designed to assess the effectiveness of a telephone counseling intervention on household members of hospitalized children in pediatric departments. Data were collected with a standardized Chinese language questionnaire. At the three-month follow-up survey, the proportions of household members who reported adopting complete smoking restriction at home (55%), did not smoke at home at all (37%), did not allow others to smoke in the car (70%), or did not allow others to smoke around the child (57%) were significantly higher than the self-reported responses at the baseline survey. The proportions of household members who reported smoking at home (49%) and in the car (22%) were significantly lower than the baseline survey. Overall, 7% of the participants had reported quitting smoking after three months. Pediatric in-patient department-based telephone counseling for smoking cessation was found to be acceptable to Chinese parents. The intervention encouraged few parents to quit smoking, but encouraged more parents to take measures to reduce children's SHS exposure.

Analysis of a thermite experiment to study low pressure corium dispersion

International Nuclear Information System (INIS)

Wilhelm, D.

2001-08-01

The report describes the recalculation of a thermite experiment in a reduced scale which simulates the discharge of molten core materials out of the pressure vessel of a light water reactor into the open compartments and the dome of the containment. The experiment was performed in the framework of a multinational effort at the Sandia National Laboratory, U.S.A. It is being followed by the DISCO program at the Forschungszentrum Karlsruhe. A computational fluid dynamics code was supplemented with specific models to recalculate the Sandia experiment in order to identify problem areas which need to be addressed in the future. Therefore, a first attempt was undertaken to extrapolate to reactor conditions. This was done in two steps to separate geometric from material scaling relationships. The study shows that important experimental results can be extrapolated according to general scaling laws but that there are sensitivities, especially when replacing thermite by corium. The results show a considerable scatter and a dependence on geometric resolution and dynamics of energy transfer between participating components. (orig.) [de

Calculation of the CAREM reactor with the HUEMUL-PUMA-THERMIT chain of codes; Calculo del reactor CAREM con la cadena de codigos HUEMUL-PUMA-THERMIT

Energy Technology Data Exchange (ETDEWEB)

Notari, Carla; Grant, Carlos R [Comision Nacional de Energia Atomica, General San Martin (Argentina)

2000-07-01

The purpose of the work was the evaluation of the the CAREM 25 reactor core, using a chain of codes (HUEMUL-PUMA-THERMIT) different to the one used in the original design (CONDOR-CITVAP-THERMIT). First, we performed a partial validation of the our codes in lattices similar to CAREM and reproduced a benchmark for simulation of gadolinium burnup. The results were considered satisfactory for this stage of the project. Then, we calculated the core along the normal operating equilibrium cycle and in hot and cold shut-down conditions. The main outcome of our evaluation confirms the general behaviour of the reference calculations except in one important point referring to the cold shut down. In this condition, the failure of one single rod of bank number 13 of the shut down system, leaves the core in a supercritical state at the beginning of the cycle and this anomaly persists during almost a third of the overall cycle. A new design of the core is proposed with minor modifications of the reference one, without introducing new types of fuel elements and keeping the same fuel management scheme. This new core fulfills all the design requirements. (author)

Recent Contributions of Air- and Biomarkers to the Control of Secondhand Smoke (SHS): A Review

Science.gov (United States)

Prignot, Jacques J.

2011-01-01

Since the publication of the US Surgeon General Reports in 1996 and 2006 and the report of the California Environmental Protection Agency in 1999, many reports have appeared on the contribution of air and biomarkers to different facets of the secondhand smoke (SHS) issue, which are the targets of this review. These recent studies have allowed earlier epidemiological surveys to be biologically validated, and their plausibility demonstrated, quantified the levels of exposure to SHS before the bans in various environments, showed the deficiencies of mechanical control methods and of partial bans and the frequently correct implementation of the efficient total bans. More stringent regulation remains necessary in the public domain (workplaces, hospitality venues, transport sector, etc.) in many countries. Personal voluntary protection efforts against SHS are also needed in the private domain (homes, private cars). The effects of SHS on the cardiovascular, respiratory and neuropsychic systems, on pregnancy and fertility, on cancers and on SHS genotoxicity are confirmed through experimental human studies and through the relationship between markers and prevalence of disease or of markers of disease risk. PMID:21556172

Recent Contributions of Air- and Biomarkers to the Control of Secondhand Smoke (SHS: A Review

Directory of Open Access Journals (Sweden)

Jacques J. Prignot

2011-03-01

Full Text Available Since the publication of the US Surgeon General Reports in 1996 and 2006 and the report of the California Environmental Protection Agency in 1999, many reports have appeared on the contribution of air and biomarkers to different facets of the secondhand smoke (SHS issue, which are the targets of this review. These recent studies have allowed earlier epidemiological surveys to be biologically validated, and their plausibility demonstrated, quantified the levels of exposure to SHS before the bans in various environments, showed the deficiencies of mechanical control methods and of partial bans and the frequently correct implementation of the efficient total bans. More stringent regulation remains necessary in the public domain (workplaces, hospitality venues, transport sector, etc. in many countries. Personal voluntary protection efforts against SHS are also needed in the private domain (homes, private cars. The effects of SHS on the cardiovascular, respiratory and neuropsychic systems, on pregnancy and fertility, on cancers and on SHS genotoxicity are confirmed through experimental human studies and through the relationship between markers and prevalence of disease or of markers of disease risk.

Comparison of Bacillus atrophaeus spore viability following exposure to detonation of C4 and to deflagration of halogen-containing thermites

Science.gov (United States)

Tringe, J. W.; Létant, S. E.; Dugan, L. C.; Levie, H. W.; Kuhl, A. L.; Murphy, G. A.; Alves, S. W.; Vandersall, K. S.; Pantoya, M. L.

2013-12-01

Energetic materials are being considered for the neutralization of spore-forming bacteria. In this study, the neutralization effects of a monomolecular explosive were compared to the effects of halogen-containing thermites. Bacillus atrophaeus spores were exposed to the post-detonation environment of a 100 g charge of the military explosive C-4 at a range of 50 cm. These tests were performed in the thermodynamically closed environment of a 506-l barometric calorimeter. Associated temperatures were calculated using a thermodynamic model informed by calculations with the Cheetah thermochemical code. Temperatures in the range of 2300-2800 K were calculated to persist for nearly the full 4 ms pressure observation time. After the detonation event, spores were characterized using optical microscopy and the number of viable spores was assessed. Results showed live spore survival rates in the range of 0.01%-1%. For the thermite tests, a similar, smaller-scale configuration was employed that examined the spore neutralization effects of two thermites: aluminum with iodine pentoxide and aluminum with potassium chlorate. Only the former mixture resulted in spore neutralization. These results indicate that the detonation environment produced by an explosive with no chemical biocides may provide effective spore neutralization similar to a deflagrating thermite containing iodine.

Comparison of Bacillus atrophaeus spore viability following exposure to detonation of C4 and to deflagration of halogen-containing thermites

International Nuclear Information System (INIS)

Tringe, J. W.; Létant, S. E.; Dugan, L. C.; Levie, H. W.; Kuhl, A. L.; Murphy, G. A.; Alves, S. W.; Vandersall, K. S.; Pantoya, M. L.

2013-01-01

Energetic materials are being considered for the neutralization of spore-forming bacteria. In this study, the neutralization effects of a monomolecular explosive were compared to the effects of halogen-containing thermites. Bacillus atrophaeus spores were exposed to the post-detonation environment of a 100 g charge of the military explosive C-4 at a range of 50 cm. These tests were performed in the thermodynamically closed environment of a 506-l barometric calorimeter. Associated temperatures were calculated using a thermodynamic model informed by calculations with the Cheetah thermochemical code. Temperatures in the range of 2300–2800 K were calculated to persist for nearly the full 4 ms pressure observation time. After the detonation event, spores were characterized using optical microscopy and the number of viable spores was assessed. Results showed live spore survival rates in the range of 0.01%–1%. For the thermite tests, a similar, smaller-scale configuration was employed that examined the spore neutralization effects of two thermites: aluminum with iodine pentoxide and aluminum with potassium chlorate. Only the former mixture resulted in spore neutralization. These results indicate that the detonation environment produced by an explosive with no chemical biocides may provide effective spore neutralization similar to a deflagrating thermite containing iodine

Comparison of Bacillus atrophaeus spore viability following exposure to detonation of C4 and to deflagration of halogen-containing thermites

Energy Technology Data Exchange (ETDEWEB)

Tringe, J. W.; Létant, S. E.; Dugan, L. C.; Levie, H. W.; Kuhl, A. L.; Murphy, G. A.; Alves, S. W.; Vandersall, K. S. [Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550 (United States); Pantoya, M. L. [Mechanical Engineering Department, Texas Tech University, Lubbock, Texas 79409 (United States)

2013-12-21

Energetic materials are being considered for the neutralization of spore-forming bacteria. In this study, the neutralization effects of a monomolecular explosive were compared to the effects of halogen-containing thermites. Bacillus atrophaeus spores were exposed to the post-detonation environment of a 100 g charge of the military explosive C-4 at a range of 50 cm. These tests were performed in the thermodynamically closed environment of a 506-l barometric calorimeter. Associated temperatures were calculated using a thermodynamic model informed by calculations with the Cheetah thermochemical code. Temperatures in the range of 2300–2800 K were calculated to persist for nearly the full 4 ms pressure observation time. After the detonation event, spores were characterized using optical microscopy and the number of viable spores was assessed. Results showed live spore survival rates in the range of 0.01%–1%. For the thermite tests, a similar, smaller-scale configuration was employed that examined the spore neutralization effects of two thermites: aluminum with iodine pentoxide and aluminum with potassium chlorate. Only the former mixture resulted in spore neutralization. These results indicate that the detonation environment produced by an explosive with no chemical biocides may provide effective spore neutralization similar to a deflagrating thermite containing iodine.

Secondhand smoke exposure (SHS) and health-related quality of life (HRQoL) in Chinese never smokers in Hong Kong.

Science.gov (United States)

Chen, Jing; Wang, Man-Ping; Wang, Xin; Viswanath, Kasisomayajula; Lam, Tai-Hing; Chan, Sophia S

2015-09-02

The evidence on the effect of secondhand smoke (SHS) on Health Related Quality of Life (HRQoL) is limited. We examined the relation between SHS and HRQoL among Chinese in Hong Kong. Adult never smokers from a probability sample of three cross-sectional waves (2010, 2012, 2013) of The Hong Kong Family and Health Information Trends Survey who completed the Cantonese-version of Short-Form 12 Health Survey Questionnaire (SF12v2) were included in the data analysis conducted in 2014. Models were used to examine associations of SHS with SF12 domains and summary scores of Physical (PCS12) and Mental Component (MCS12) with subgroups analysis by SHS locations. After adjustments, SHS was associated with lower scores on all SF12 domains except physical functioning. PCS12 (regress coefficient=-0.76, 95% CI -1.34 to -0.17) and MCS12 (regress coefficient=-1.35, 95% CI -2.06 to -0.64) were lower in those with SHS exposure than those non-exposed. Those exposed to SHS in outdoor public places had lower scores on most SF12 domains and PSC12 and MCS12. SHS exposure in one's home and workplace was associated with lower scores on role physical, body pain and role emotional while SHS exposure in friends' homes was additionally associated with lower social functioning and mental health scores. Lower MCS12 was associated with SHS exposure at all locations except one's home. Our study showed that SHS exposure, particularly in outdoor public places, was associated with decreased HRQoL. It can provide new evidence for stronger smoke-free policies on public places and promoting smoke-free homes. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Preparation of molybdenum borides by combustion synthesis involving solid-phase displacement reactions

International Nuclear Information System (INIS)

Yeh, C.L.; Hsu, W.S.

2008-01-01

Preparation of molybdenum borides of five different phases in the Mo-B binary system (including Mo 2 B, MoB, MoB 2 , Mo 2 B 5 , and MoB 4 ) was performed by self-propagating high-temperature synthesis (SHS) with two kinds of the reactant samples. When elemental powder compacts with an exact stoichiometry corresponding to the boride phase were employed, self-sustaining reaction was only achieved in the sample with Mo:B = 1:1 and nearly single-phase MoB was yielded. Therefore, the other four boride compounds were prepared from the reactant compacts composed of MoO 3 , Mo, and B powders, within which the displacement reaction of MoO 3 with boron was involved in combustion synthesis. Experimental evidence shows that the extent of displacement reaction in the overall reaction has a significant impact on sustainability of the synthesis reaction, combustion temperature, reaction front velocity, and composition of the end product. An increase in the solid-phase displacement reaction taking place during the SHS process contributes more heat flux to the synthesis reaction, thus resulting in the increase of combustion temperature and enhancement of the reaction front velocity. Based upon the XRD analysis, formation of Mo 2 B, MoB 2 , and Mo 2 B 5 as the dominant boride phase in the end product was successful through the SHS reaction with powder compacts under appropriate stoichiometries between MoO 3 , Mo, and B. However, a poor conversion was observed in the synthesis of MoB 4 . The powder compact prepared for the production of MoB 4 yielded mostly Mo 2 B 5

The Effect of a Pilot Pediatric In-Patient Department-Based Smoking Cessation Intervention on Parental Smoking and Children’s Secondhand Smoke (SHS Exposure in Guangxi, China

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Kaiyong Huang

2016-11-01

Full Text Available Children’s exposure to secondhand smoke (SHS at home has numerous adverse health effects. This study evaluated the effects of a pediatric in-patient department-based pilot smoking cessation intervention for household members to reduce children’s SHS exposure and encourage smoking cessation. A pre-post test design study was designed to assess the effectiveness of a telephone counseling intervention on household members of hospitalized children in pediatric departments. Data were collected with a standardized Chinese language questionnaire. At the three-month follow-up survey, the proportions of household members who reported adopting complete smoking restriction at home (55%, did not smoke at home at all (37%, did not allow others to smoke in the car (70%, or did not allow others to smoke around the child (57% were significantly higher than the self-reported responses at the baseline survey. The proportions of household members who reported smoking at home (49% and in the car (22% were significantly lower than the baseline survey. Overall, 7% of the participants had reported quitting smoking after three months. Pediatric in-patient department-based telephone counseling for smoking cessation was found to be acceptable to Chinese parents. The intervention encouraged few parents to quit smoking, but encouraged more parents to take measures to reduce children’s SHS exposure.

Preparation of MoB and MoB-MoSi2 composites by combustion synthesis in SHS mode

International Nuclear Information System (INIS)

Yeh, C.L.; Hsu, W.S.

2007-01-01

Combustion synthesis in the mode of self-propagating high-temperature synthesis (SHS) was carried out in the Mo-B and Mo-B-Si systems for the preparation of molybdenum boride MoB and the composite of MoB-MoSi 2 from elemental powder compacts. Under a preheating temperature above 150 deg. C , the reaction of Mo with boron in the sample compact of Mo:B = 1:1 is characterized by a planar combustion front propagating in a self-sustaining and steady manner. As the preheating temperature or sample compaction density increased, combustion temperature was found to increase and the propagation rate of the combustion front was correspondingly enhanced. Moreover, the XRD analysis provides evidence of yielding nearly single-phase α-MoB from the Mo-B sample at equiatomic stoichiometry. In the synthesis of MoB-MoSi 2 composites, the starting stoichiometry of the Mo-B-Si powder compact was varied so as to produce the final composites containing 20-80 mol% MoB. It was also found the increase of flame-front velocity and combustion temperature with increasing MoB content formed in the composite. The composition analysis by XRD shows excellent conversion from the Mo-B-Si powder compact to the MoB-MoSi 2 composite through the SHS reaction; that is, in addition to a small amount of Mo 5 Si 3 , the as-synthesized composite is composed entirely of MoB and MoSi 2

Production of carbon nanotubes using mechanical milling in the presence of an exothermic reaction

International Nuclear Information System (INIS)

Karimi, E.Z.; Zebarjad, S.M.; Khaki, J. Vahdati; Izadi, H.

2010-01-01

Carbon nanotubes (CNTs) have shown promising potential for many applications in field of engineering due to their unusual significant properties. A major challenge for the industrial applications of CNTs is the large-quantity production. In this field, one new method for CNT production is annealing the ball milled graphite powder. The annealing process should be done in high temperature (1200-1400 o C) and needs time more than 6 h. The novel process introduced in this paper is elimination the annealing stage thorough a thermite reaction. The necessity heat for the conversion of milling products to CNTs was generated in the milling chamber by an exothermic reaction. In addition, the reaction products acted as catalysts to the CNT formation process. The adiabatic temperatures of 1809, 2000 and 2325 K were selected according to balancing graphite and thermite mixture (Aluminum + Iron oxide powders) for exothermic reaction. The results of thermo gravimetric analysis (TGA) test proved that CNT formation strongly depends on adiabatic temperature. The results of microscopic evaluation done by transition electron microscope (TEM) showed that at higher adiabatic temperature CNTs could be produced.

Characterisation of Ceramic-Coated 316LN Stainless Steel Exposed to High-Temperature Thermite Melt and Molten Sodium

Science.gov (United States)

Ravi Shankar, A.; Vetrivendan, E.; Shukla, Prabhat Kumar; Das, Sanjay Kumar; Hemanth Rao, E.; Murthy, S. S.; Lydia, G.; Nashine, B. K.; Mallika, C.; Selvaraj, P.; Kamachi Mudali, U.

2017-11-01

Currently, stainless steel grade 316LN is the material of construction widely used for core catcher of sodium-cooled fast reactors. Design philosophy for core catcher demands its capability to withstand corium loading from whole core melt accidents. Towards this, two ceramic coatings were investigated for its application as a layer of sacrificial material on the top of core catcher to enhance its capability. Plasma-sprayed thermal barrier layer of alumina and partially stabilised zirconia (PSZ) with an intermediate bond coat of NiCrAlY are selected as candidate material and deposited over 316LN SS substrates and were tested for their suitability as thermal barrier layer for core catcher. Coated specimens were exposed to high-temperature thermite melt to simulate impingement of molten corium. Sodium compatibility of alumina and PSZ coatings were also investigated by exposing samples to molten sodium at 400 °C for 500 h. The surface morphology of high-temperature thermite melt-exposed samples and sodium-exposed samples was examined using scanning electron microscope. Phase identification of the exposed samples was carried out by x-ray diffraction technique. Observation from sodium exposure tests indicated that alumina coating offers better protection compared to PSZ coating. However, PSZ coating provided better protection against high-temperature melt exposure, as confirmed during thermite melt exposure test.

Time-resolved XRD study of TiC-TiB2 composites obtained by SHS

International Nuclear Information System (INIS)

Contreras, L.; Turrillas, X.; Vaughan, G.B.M.; Kvick, A.; Rodriguez, M.A.

2004-01-01

Composites of TiC and TiB 2 were prepared by self-propagating high-temperature synthesis (SHS). Two routes were attempted; from the elements and from a mixture of anatase, boron oxide, graphite and magnesium. The reactions were monitored in situ by synchrotron X-ray diffraction (λ = 0.26102 A). The powder mixtures were compacted as cylindrical pellets and upon ignition diffraction patterns were collected every 65 ms with a CCD camera. TiC was the first phase to form, followed by TiB 2 . The reactions take place in time scales of 0.1 s. The temperature profile for the first route was established from the peak position and the known thermal expansion coefficients. The microstructure of the final products was different: particles of 10 μm for the first and submicron for the second. The viability of the second route to produce ceramic powders in a cheaper way was confirmed

Experimental investigation on AC unit integrated with sensible heat storage (SHS)

Science.gov (United States)

Aziz, N. A.; Amin, N. A. M.; Majid, M. S. A.; Hussin, A.; Zhubir, S.

2017-10-01

The growth in population and economy has increases the energy demand and raises the concerns over the sustainable energy source. Towards the sustainable development, energy efficiency in buildings has become a prime objective. In this paper, the integration of thermal energy storage was studied. This paper presents an experimental investigation on the performance of an air conditioning unit integrated with sensible heat storage (SHS) system. The results were compared to the conventional AC systems in the terms of average electricity usage, indoor temperature and the relative humidity inside the experimented room (cabin container). Results show that the integration of water tank as an SHS reduces the electricity usage by 5%, while the integration of well-insulated water tank saves up to 8% of the electricity consumption.

Calculation of the CAREM reactor with the HUEMUL-PUMA-THERMIT chain of codes

International Nuclear Information System (INIS)

Notari, Carla; Grant, Carlos R.

2000-01-01

The purpose of the work was the evaluation of the the CAREM 25 reactor core, using a chain of codes (HUEMUL-PUMA-THERMIT) different to the one used in the original design (CONDOR-CITVAP-THERMIT). First, we performed a partial validation of the our codes in lattices similar to CAREM and reproduced a benchmark for simulation of gadolinium burnup. The results were considered satisfactory for this stage of the project. Then, we calculated the core along the normal operating equilibrium cycle and in hot and cold shut-down conditions. The main outcome of our evaluation confirms the general behaviour of the reference calculations except in one important point referring to the cold shut down. In this condition, the failure of one single rod of bank number 13 of the shut down system, leaves the core in a supercritical state at the beginning of the cycle and this anomaly persists during almost a third of the overall cycle. A new design of the core is proposed with minor modifications of the reference one, without introducing new types of fuel elements and keeping the same fuel management scheme. This new core fulfills all the design requirements. (author)

A DMS kinetic study of the boron oxides vapor in the combustion front of SHS system Mo + B

International Nuclear Information System (INIS)

Kashireninov, O.E.; Yuranov, I.A.

1994-01-01

The distribution of the boron oxides vapor in the combustion wave of the SHS system Mo + B has been studied by the dynamic mass spectrometry technique (DMS) to test the thermodynamically based hypothesis for the key role of gas-phase transport in solid-state combustion. The molecular beam sampling of the gases over the burning tablet was performed by a stationary probe cone from the moving combustion wave. Ion currents of boron oxides were recorded at 10--20 ms intervals that afforded spatial resolution of 0.1--0.2 mm. It has been found that the distribution of the boron oxides vapor pressure along the combustion wave corresponds to the known zones of preheating, reaction, and postcombustion. The rapid increase of B 2 O 2 pressure takes place in the preheating zone as a result of the reaction B(s) + B 2 O 3 (g) = B 2 O 2 (g). Boron oxides are not observed over the reaction zone because of their complete decay in the reaction with Mo(s) to form molybdenum boride(s). The appearance The appearance of boron oxide vapors over the postcombustion zone is due to the evaporation of B 2 O 3 (l). The effective kinetic parameters are estimated from the data obtained. The results show that solid-state combustion of the Mo + B system proceeds predominantly through formation of gas-phase boron oxides

Rural Electrification Program in Indonesia: Comparing SEHEN and SHS Program

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Maxensius Tri Sambodo

2015-07-01

Full Text Available In 2014, the Indonesian government has targets to obtain 80% of electrification ratio and 98.9% of rural electrification ratio. Extending the grid and off-grid connection has been done to obtain the targets. This paper aims to compare two main programs on rural electrification namely Super Extra Energy Saving (Super Ekstra Hemat Energi, SEHEN that is belong to PLN (state owned company in electricity and the Solar Home System (SHS that is financed by the Ministry of Energy and Mineral Resources (MEMR. Indonesia has started the rural electrification program in the late 1950s, but how to provide electricity in a sustainable ways both organizationally and institutionally still become a big challenge. The experiences from East Nusa Tenggara provinces showed that both SEHEN and SHS can instantly improve electrification ratio, but government needs to synchronize the technical, administrative, and financial aspect from the two programs. Without any improvements in designing the program, we argue that the existing program is not sustainable.

Inhibition of the receptor for advanced glycation end-products (RAGE) protects from secondhand smoke (SHS)-induced intrauterine growth restriction IUGR in mice.

Science.gov (United States)

Lewis, Joshua B; Mejia, Camilo; Jordan, Clinton; Monson, Troy D; Bodine, Jared S; Dunaway, Todd M; Egbert, Kaleb M; Lewis, Adam L; Wright, Tanner J; Ogden, K Connor; Broberg, Dallin S; Hall, Parker D; Nelson, Shawn M; Hirschi, Kelsey M; Reynolds, Paul R; Arroyo, Juan A

2017-12-01

Intrauterine growth restriction (IUGR) is a disease affecting 10% of all pregnancies. IUGR is associated with maternal, fetal, or placental abnormalities. Studies investigating the effects of secondhand smoke (SHS) exposure and IUGR are limited. The receptor for advanced glycation end-products (RAGE) is a pro-inflammatory transmembrane receptor increased by SHS in the placenta. We tested the hypothesis that inhibition of RAGE during SHS exposure protects from smoke-induced IUGR. C57BL/6 mice were exposed to SHS or SHS + semi-synthetic glycosaminoglycan ethers (SAGEs) known to inhibit RAGE signaling. Trophoblast cells were treated with cigarette smoke extract (CSE) with or without SAGEs in order to address the effects of RAGE inhibition during trophoblast invasion in vitro. SHS-treated mice demonstrated a significant reduction in fetal weight (7.35-fold, P ≤ 0.0001) and placental weight (1.13-fold, P ≤ 0.0001) compared with controls. Mice co-treated with SHS and SAGEs were protected from SHS-induced fetal weights decreases. SHS treatment of C57BL/6 mice activated placental extracellular signal-regulated kinase (ERK) (3.0-fold, P ≤ 0.05), JNK (2.4-fold, P ≤ 0.05) and p38 (2.1-fold, P ≤ 0.05) and the expression of inflammatory mediators including TNF-α (1.34-fold, P ≤ 0.05) and IL-1β (1.03-fold, P ≤ 0.05). SHS-mediated activation of these molecules was reduced to basal levels when SAGE was co-administered. Invasion of trophoblast cells decreased 92% (P < 0.002) when treated with CSE and CSE-mediated invasion was completely reversed by SAGEs. We conclude that RAGE inhibition protects against fetal weight loss during SHS-induced IUGR. These studies provide insight into tobacco-mediated IUGR development and clarify avenues that may be helpful in the alleviation of placental complications.

REACTION KINETICS SELF-PROPOGATION REGIME DURING PRE-IGNITION PERIOD

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D. D. Polishchuk

2015-11-01

Full Text Available Self-propagation high temperature synthesis (SHS technological regulations application is mainly limited by transformation processes taking place in the pre-ignition period. Zn-S, Zn-Se, Ti-C and 3Ni-Al small sample systems ignition experimental study was carried out under heating conditions in inert atmosphere with temperature values T = 1200K.It was shown that at this temperature level a chemical reaction can be initiated, turning into a self-sustaining mode. Wherein the reaction limiting factors can be mass transfer processes. Ignition temperatures were determined and plotted via the samples size. A physical ignition model was developed assuming the pre-ignition period limiting reaction Arrhenius law.The inverse combustion problem solution made it possible to calculate the low-temperature (T = 800 ÷ 1200K reaction kinetic constant values. Comparison thus obtained values  with the known data of other researchers showed their good agreement.Activation energy values for the Zn-S system were used to calculate the heat wave propagation speed. This value appeared to coincide with experimental values.Obtained results analysis leads to the conclusion about the availability and justification for the proposed method of express-analysis of presupposed, but previously not studied SHS systems. The results thus obtained allow us to estimate conditions for the SHS technology implementation, the reactor characteristic sizes and the thermal wave’s propagation speed.

Using mathematical modelling of the changes in the characteristics of the bodies during SHS-process for porous ceramic filters manufacture

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Юлія Славоміровна Повстяна

2016-11-01

Full Text Available Porous ceramic materials possess great lifetime, high mechanical strength, are resistant to household effects and easy to use. The binder volume fraction and normalized pressure as a function of the temperature in the SHS process in the ceramic body have been studied in this work. Basing on theoretical calculations the temperature range of the binder burnout has been determined. The theoretical results can be used to predict and obtain porous ceramic filters with predetermined characteristics. The theoretical calculations were used in the manufacture of experimental samples of porous ceramic bodies obtained on the basis of 18H2N4MA steel scale and the saponite. Pressing in a hydraulic press was used to manufacture ceramic pieces. Unilateral press mould made of stainless steel was used to form the samples. Pressing was carried out in the pressure range of 10-25 MPa. The resulting pieces were formed in cylinders of 30mm in diameter and 40 mm height. Sintering of the samples was conducted in the modernized reactor for the SHS process. Mathematical justification of SHS process made it possible to avoid the formation of cracks in the ceramic bodies and crumble areas

EFFECT OF ULTRASOUND ACTIVATION OF SHS-CHARGE ON THE FINAL PRODUCT

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V. V. Klubovich

2016-01-01

Full Text Available The paper describes the effect of ultrasound activation of dolomite, which is used for producing refractory material by the SHS method, on the final product. X-ray investigation has demonstrated that ultrasound activation of the initial charge brings about changes in the phase composition of the synthesized product.

Health impacts of exposure to second hand smoke (SHS) amongst a highly exposed workforce: survey of London casino workers.

Science.gov (United States)

Pilkington, Paul A; Gray, Selena; Gilmore, Anna B

2007-09-21

Casino workers are exposed to high levels of secondhand smoke (SHS) at work, yet remain at risk of being excluded from smoke-free legislation around the world. If the prime motivation for smoke-free legislation is the protection of workers, then a workforce experiencing ill-health associated with SHS exposure should not be excluded from legislation. This study aimed to determine the prevalence of respiratory and sensory irritation symptoms among a sample of casino workers, to identify any association between the reporting of symptoms and exposure to SHS at work, and to compare the prevalence of symptoms with that in other workers exposed to SHS. A postal questionnaire survey of 1568 casino workers in London. Using multivariate analysis we identified predictors of respiratory and sensory irritation symptoms. 559 workers responded to the questionnaire (response of 36%). 91% of casino workers reported the presence of one or more sensory irritation symptoms in the previous four weeks, while the figure was 84% for respiratory symptoms. The presence of one or more sensory irritation symptoms was most strongly associated with reporting the highest exposure to SHS at work (OR 3.26; 1.72, 6.16). This was also true for reporting the presence of one or more respiratory irritation symptoms (OR 2.24; 1.34, 3.74). Prevalence of irritation symptoms in the casino workers was in general appreciably higher than that reported in studies of bar workers. Our research supports the need for comprehensive smoke-free legislation around the world, covering all indoor workplaces including casinos.

Health impacts of exposure to second hand smoke (SHS amongst a highly exposed workforce: survey of London casino workers

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Gilmore Anna B

2007-09-01

Full Text Available Abstract Background Casino workers are exposed to high levels of secondhand smoke (SHS at work, yet remain at risk of being excluded from smoke-free legislation around the world. If the prime motivation for smoke-free legislation is the protection of workers, then a workforce experiencing ill-health associated with SHS exposure should not be excluded from legislation. This study aimed to determine the prevalence of respiratory and sensory irritation symptoms among a sample of casino workers, to identify any association between the reporting of symptoms and exposure to SHS at work, and to compare the prevalence of symptoms with that in other workers exposed to SHS. Methods A postal questionnaire survey of 1568 casino workers in London. Using multivariate analysis we identified predictors of respiratory and sensory irritation symptoms. Results 559 workers responded to the questionnaire (response of 36%. 91% of casino workers reported the presence of one or more sensory irritation symptoms in the previous four weeks, while the figure was 84% for respiratory symptoms. The presence of one or more sensory irritation symptoms was most strongly associated with reporting the highest exposure to SHS at work (OR 3.26; 1.72, 6.16. This was also true for reporting the presence of one or more respiratory irritation symptoms (OR 2.24; 1.34, 3.74. Prevalence of irritation symptoms in the casino workers was in general appreciably higher than that reported in studies of bar workers. Conclusion Our research supports the need for comprehensive smoke-free legislation around the world, covering all indoor workplaces including casinos.

Particle-particle interactions in aluminum reduction of boron oxide

International Nuclear Information System (INIS)

Logan, K.V.; McLemore, W.J.S.; Sparrow, J.T.

1988-01-01

The Georgia Tech Research Institute has been studying the use of thermite reactions for the production of specialized compounds since the mid-1950's. One of the goals of the research at GTRI is to define the reaction mechanism in order to be ble to predict the resultant reaction behaviour and thus prevent hazardous conditions. Thermite processing advantages are discussed in this paper. A typical thermite type of reaction to produce a composite titanium diboride/alumina is shown. The reactions typically use three starting materials for the production of a specific compound. A preliminary experimental mechanistic model of the extremely exothermic oxidation-reduction reaction is being developed

Self-sustained high-temperature reactions : Initiation, propagation and synthesis

NARCIS (Netherlands)

Martinez Pacheco, M.

2007-01-01

Self-Propagating High-Temperature Synthesis (SHS), also called combustion synthesis is an exothermic and self-sustained reaction between the constituents, which has assumed significance for the production of ceramics and ceramic-metallic materials (cermets), because it is a very rapid processing

Successful PV SHS project in developing countries? barriers and way foreword

International Nuclear Information System (INIS)

Villers, T. de; Watchueng, S.; Shanker, A.; Rambaud-Measson, D.

2004-01-01

The implementation of a solar home system (SHS) programme in developing countries is complex and its success is dependant on many factors that are usually difficult to handle. The objective of this paper is to address financial and organisational aspects barriers and measures to PV programme implementation drawn from two specific projects in West Africa. Technical aspects on quality control and monitoring are also discussed. (authors)

Applications of the thermit code to 3D thermal hydraulic analysis of LWR cores

International Nuclear Information System (INIS)

Reed, W.H.

1979-01-01

The THERMIT code calculates the three-dimensional transient thermal hydraulic behavior of light water reactor cores. Its two-fluid dynamics equations for two-phase flow offer improved physical modelling capability needed in the context of calculation coupled to neutron kinetics for feedback. The numerical fluid dynamics method was chosen for reliability over a wider range of transients. An improved heat transfer numerical method is presented which gives better numerical stability and accuracy. A number of example calculations are discussed which give an idea of the power and flexibility of the code

Silicon carbide production by Self-Propagating High Temperature (SHS) technique

International Nuclear Information System (INIS)

Lima, Eduardo de Souza; Schneider, Pedro Luiz; Mattoso, Irani Guedes; Costa, Carlos Roberto Correia da; Louro, Luis Henrique Leme

1997-01-01

Samples of silicon carbide (SiC) were synthesized from a mixture of silicon and carbon powders, using the Self-Propagating High Temperature Synthesis (SHS) technique. Three mixtures were tried, using silicon particles of the same average size but carbon particles of different average sizes. The method tried is characterized by an ignition temperature of 1450 deg C and the short duration of the synthesis ( 2-3 min). The samples were characterized by X-ray diffraction and scattering electron microscopy. (author)

Simulation of sodium boiling experiments with THERMIT sodium version

International Nuclear Information System (INIS)

Huh, K.Y.

1982-05-01

Natural and forced convection experiments (SBTF and French) are simulated with the sodium version of the thermal-hydraulic computer code THERMIT. Simulation is done for the test section with the pressure-velocity boundary condition and subsequently extended to the whole loop. For the test section simulation, a steady-state and transient calculations are performed and compared with experimental data. For the loop simulation, two methods are used, a simulated 1-D loop and an actual 1-D loop. In the simulated 1-D loop analysis, the vapor density is increased by one hundred and two hundred times to avoid the code failure and the results still showed some of the important characteristics of the two-phase flow oscillation in a loop. A mathematical model is suggested for the two-phase flow oscillation. In the actual 1-D loop, only the single phase calculation was performed and turned out to be nearly the same as the simulated 1-D loop single phase results

Combustion Synthesis Reaction Behavior of Cold-Rolled Ni/Al and Ti/Al Multilayers

Science.gov (United States)

2011-04-01

reaction modes of the films. Anselmi-Tamburini and Munir (21) studied the 2 SHS reaction in laminated Ni/Al foils and established a sequence of... convolution of three peaks. The very large broad peak, centered on position C, contains a superimposed peak appearing as a shoulder (position A) and a

Production of monoclonal antibodies for Avian Metapneumovirus (SHS-BR-121 isolated in Brazil

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LT Coswig

2007-12-01

Full Text Available Avian Metapneumovirus (aMPV, also called Turkey Rhinotracheitis Virus (TRTV, is an upper respiratory tract infection of turkeys, chickens and other avian species. Five monoclonal antibodies (MAbs were created against the Brazilian isolate (SHS-BR-121 of aMPV, MAbs 1A5B8; 1C1C4; 2C2E9 and 2A4C3 of IgG1 and MAb 1C1F8 of IgG2a. Four Mabs (1A5B8; 1C1C4; 2C2E9 and 2A4C3 showed neutralizing activity and three (1A5B8; 1C1C4 and 2A4C3 inhibited cellular fusion in vitro. These MAbs were used to investigate antigenic relationship among three strains (SHS-BR-121, STG 854/88 and TRT 1439/91 of aMPV subtypes A and B using cross-neutralization test. The results confirm that the monoclonal antibodies described can be used as a valuable tool in the epizootiological and serological studies, and also for the specific diagnosis of the subtypes in the infection for Avian Metapneumovirus.

Preparation of Fe-Al Intermetallic / TiC-Al2O3 Ceramic Composites from Ilmenite by SHS

Institute of Scientific and Technical Information of China (English)

无

2007-01-01

Fe-Al intermetallic/TiC-Al2O3 ceramic composites were successfully prepared by self-propagating high-temperature synthesis (SHS) from natural ilmenite, aluminium and carbon as the raw materials. The effects of carbon sources, preheating time and heat treatment temperature on synthesis process and products were investigated in detail, and the reaction process of the FeTiO3-Al-C system was also discussed.It is shown that the temperature and velocity of the combustion wave are higher when graphite is used as the carbon source, which can reflect the effect of the carbon source structure on the combustion synthesis;Prolonging the preheating time or heat treatment temperature is beneficial to the formation of the ordered intermetallics; The temperature and velocity of the combustion wave arc improved, but the disordered alloys are difficult to eliminate with the preheating time prolonged. The compound powders mainly containing ordered Fe3Al intermetallic can be prepared through heat treatment at 750 ℃.

The socio-technical barriers to Solar Home Systems (SHS) in Papua New Guinea: 'Choosing pigs, prostitutes, and poker chips over panels'

International Nuclear Information System (INIS)

Sovacool, Benjamin K.; D'Agostino, Anthony L.; Jain Bambawale, Malavika

2011-01-01

This study explores the socio-technical barriers to Solar Home Systems (SHS) in Papua New Guinea. The authors collected primary data through semi-structured research interviews conducted over the course of February 2010-April 2010. Respondents included government officials, financiers, planners, commercial distributors and companies, teachers and rural villagers in addition to members of civil society, academics, consultants, and trainers. These interviews were supplemented with site visits to Port Moresby, Goroka, and Madang, and field research in the villages of Akameku, Asaroka, Lufa, Kundiawa, Okifa, Simbu, and Talidig. The study draws from these interviews and visits to discuss four types of barriers. Technical barriers relate to substandard equipment and logistical problems. Economic barriers include high rates of poverty, misconceptions about the role of currency, and lack of financing. Political barriers include poor institutional capacity and a government commitment to fossil-fueled grid electrification. Social barriers encompass unrealistic expectations about what SHS can provide along with jealousy, theft, vandalism, and unfamiliarity with solar technology. - Research highlights: → Solar Home Systems (SHS) are impeded by a collection of different barriers in Papua New Guinea. → Technical barriers relate to substandard equipment and logistical problems. → Economic barriers include high rates of poverty, misconceptions about the role of currency, and lack of financing.→ Political barriers include poor institutional capacity and a government commitment to fossil-fueled grid electrification. → Social barriers encompass unrealistic expectations about what SHS can provide along with jealousy, theft, vandalism, and unfamiliarity with solar technology.

Self propagating high temperature synthesis (SHS) of the Fe(TiMo)C master alloy using ferroalloys

International Nuclear Information System (INIS)

Erauskin, J. I.; Sargyan, A.; Arana, J. L.

2009-01-01

Titanium monocarbide TiC is very hard, stable both at high and low temperatures and relatively easy to synthesize from its constituent elements by SHS. Nevertheless, it is difficult to use, as alloying element, in the reinforcement of steels manufactured by liquid metallurgy due to its low wettability by molten steel. To achieve this purpose and due to its better wettability, it is more appropriate to use a master alloy formed by the complex carbide (TiMo)C bonded in Fe. The simplest and most economic way to fabricate such a master alloy Fe(TiMo)C is, again, by SHS, with the added advantage that it can be manufactured using the commercial ferroalloys FeTi and FeMo instead of the individual elements Fe, Ti and Mo. In this work, we describe such a process as well as the characteristics of the master alloy obtained. (Author) 13 refs

Determinants of exposure to second-hand tobacco smoke (SHS) among current non-smoking in-school adolescents (aged 11-18 years) in South Africa: results from the 2008 GYTS study.

Science.gov (United States)

Peltzer, Karl

2011-09-01

The aim of this study was to estimate the prevalence and identify correlates of second-hand tobacco smoke (SHS) among 6,412 current non-smoking school-going adolescents (aged 11 to 18 years) in South Africa. A cross-sectional study was carried out in 2008 in South Africa within the framework of the Global Youth Tobacco Survey. Overall, 25.7% of students were exposed to SHS at home, 34.2% outside of the home and 18.3% were exposed to SHS at home and outside of the home. Parental and close friends smoking status, allowing someone to smoke around you and perception that passive smoking was harmful were significant determinants of adolescent's exposure to both SHS at home and outside of the home. Identified factors can inform the implementation of public health interventions in order to reduce passive smoking among adolescents.

Effect of Heating Rate on the Formation of Intermetallics during SHS Process

Czech Academy of Sciences Publication Activity Database

Novák, P.; Michalcová, A.; Školáková, A.; Průša, F.; Kříž, J.; Marek, I.; Kubatík, Tomáš František; Karlík, M.; Haušild, P.; Kopeček, Jaromír

2015-01-01

Roč. 128, č. 4 (2015), s. 561-563 ISSN 0587-4246. [International Symposium on Physics of Materials (ISPMA13)/13./. Prague, 31.08.2014-04.09.2014] R&D Projects: GA ČR(CZ) GA14-03044S Institutional support: RVO:61389021 ; RVO:68378271 Keywords : Self-propagating high-temperature synthesis (SHS) * Differential thermal analysis Subject RIV: JK - Corrosion ; Surface Treatment of Materials Impact factor: 0.525, year: 2015 http://przyrbwn.icm.edu.pl/APP/PDF/128/a128z4p22.pdf

The socio-technical barriers to Solar Home Systems (SHS) in Papua New Guinea: 'Choosing pigs, prostitutes, and poker chips over panels'

Energy Technology Data Exchange (ETDEWEB)

Sovacool, Benjamin K., E-mail: bsovacool@nus.edu.s [Lee Kuan Yew School of Public Policy, National University of Singapore, 469C Bukit Timah Road, Singapore 259772 (Singapore); D' Agostino, Anthony L.; Jain Bambawale, Malavika [Lee Kuan Yew School of Public Policy, National University of Singapore, 469C Bukit Timah Road, Singapore 259772 (Singapore)

2011-03-15

This study explores the socio-technical barriers to Solar Home Systems (SHS) in Papua New Guinea. The authors collected primary data through semi-structured research interviews conducted over the course of February 2010-April 2010. Respondents included government officials, financiers, planners, commercial distributors and companies, teachers and rural villagers in addition to members of civil society, academics, consultants, and trainers. These interviews were supplemented with site visits to Port Moresby, Goroka, and Madang, and field research in the villages of Akameku, Asaroka, Lufa, Kundiawa, Okifa, Simbu, and Talidig. The study draws from these interviews and visits to discuss four types of barriers. Technical barriers relate to substandard equipment and logistical problems. Economic barriers include high rates of poverty, misconceptions about the role of currency, and lack of financing. Political barriers include poor institutional capacity and a government commitment to fossil-fueled grid electrification. Social barriers encompass unrealistic expectations about what SHS can provide along with jealousy, theft, vandalism, and unfamiliarity with solar technology. - Research highlights: {yields} Solar Home Systems (SHS) are impeded by a collection of different barriers in Papua New Guinea. {yields} Technical barriers relate to substandard equipment and logistical problems. {yields} Economic barriers include high rates of poverty, misconceptions about the role of currency, and lack of financing.{yields} Political barriers include poor institutional capacity and a government commitment to fossil-fueled grid electrification. {yields} Social barriers encompass unrealistic expectations about what SHS can provide along with jealousy, theft, vandalism, and unfamiliarity with solar technology.

Determinants of Exposure to Second-Hand Tobacco Smoke (SHS among Current Non-Smoking In-School Adolescents (aged 11–18 years in South Africa: Results from the 2008 GYTS Study

Directory of Open Access Journals (Sweden)

Karl Peltzer

2011-08-01

Full Text Available The aim of this study was to estimate the prevalence and identify correlates of second-hand tobacco smoke (SHS among 6,412 current non-smoking school-going adolescents (aged 11 to 18 years in South Africa. A cross-sectional study was carried out in 2008 in South Africa within the framework of the Global Youth Tobacco Survey. Overall, 25.7% of students were exposed to SHS at home, 34.2% outside of the home and 18.3% were exposed to SHS at home and outside of the home. Parental and close friends smoking status, allowing someone to smoke around you and perception that passive smoking was harmful were significant determinants of adolescent’s exposure to both SHS at home and outside of the home. Identified factors can inform the implementation of public health interventions in order to reduce passive smoking among adolescents.

Large-scale atomistic simulations of nanostructured materials based on divide-and-conquer density functional theory

Directory of Open Access Journals (Sweden)

Vashishta P.

2011-05-01

Full Text Available A linear-scaling algorithm based on a divide-and-conquer (DC scheme is designed to perform large-scale molecular-dynamics simulations, in which interatomic forces are computed quantum mechanically in the framework of the density functional theory (DFT. This scheme is applied to the thermite reaction at an Al/Fe2O3 interface. It is found that mass diffusion and reaction rate at the interface are enhanced by a concerted metal-oxygen flip mechanism. Preliminary simulations are carried out for an aluminum particle in water based on the conventional DFT, as a target system for large-scale DC-DFT simulations. A pair of Lewis acid and base sites on the aluminum surface preferentially catalyzes hydrogen production in a low activation-barrier mechanism found in the simulations

Ceramic Materials in a Ti–C–Co–Ca3(PO42–Ag–Mg System Obtained by MA SHS for the Deposition of Biomedical Coatings

Directory of Open Access Journals (Sweden)

Artem Potanin

2017-09-01

Full Text Available This study aimed to obtain biocompatible ceramic materials in a Ti–C–Co–Ca3(PO42–Ag–Mg system by the combustion mode of mechanically activated (MA reaction mixtures. The influence of the MA time on the reaction ability capability of the mixtures, on their structural and chemical homogeneity, on the combustion parameters and structural-phase conversions in the combustion wave, as well as on the structure and phase composition of the electrode materials has been researched. It was found that the intense treatment of powder mixtures causes plastic deformation of components, the formation of lamellar composite granules, a reduction in the sizes of coherent scattering regions, and also the formation of minor amounts of products. The influence of the activation duration of the ignition temperature and heat release during the combustion of the reaction mixtures was studied. By the method of quenching the combustion front, it was demonstrated that in a combustion wave, chemical transformations occur within the lamellar structures formed during the process of mechanoactivation. It was shown that in the combustion wave, parallel chemical reactions of Ti with C as well as Ti with Co and Ca3(PO42 occur, with a Ti–Co-based melt forming the reaction surface. Ceramic electrodes with different contents of Ag and Mg were synthesized by force self-propagating high-temperature synthesis (SHS-pressing technology using the MA mixtures. The microstructure of the materials consisted of round-shaped grains of nonstoichiometric titanium carbide TiCx grains, intermetallic matrix (TiCo, TiCo2, CoTiP, inclusions of Ca and Mg oxides, and grains of the Ag-based solid solution. An increased content of Ag and Mg in the composition of the electrodes, as well as an increased MA duration, leads to an enlargement of the inclusions of the Ag-containing phase size and deterioration in the uniformity of their distribution.

Smart Demand Response Based on Smart Homes

Directory of Open Access Journals (Sweden)

Jingang Lai

2015-01-01

Full Text Available Smart homes (SHs are crucial parts for demand response management (DRM of smart grid (SG. The aim of SHs based demand response (DR is to provide a flexible two-way energy feedback whilst (or shortly after the consumption occurs. It can potentially persuade end-users to achieve energy saving and cooperate with the electricity producer or supplier to maintain balance between the electricity supply and demand through the method of peak shaving and valley filling. However, existing solutions are challenged by the lack of consideration between the wide application of fiber power cable to the home (FPCTTH and related users’ behaviors. Based on the new network infrastructure, the design and development of smart DR systems based on SHs are related with not only functionalities as security, convenience, and comfort, but also energy savings. A new multirouting protocol based on Kruskal’s algorithm is designed for the reliability and safety of the SHs distribution network. The benefits of FPCTTH-based SHs are summarized at the end of the paper.

Selection of Compositions in Ti-Cr-C-Steel, Ti-B, Ti-B-Me Systems and Establishing Synthesis Parameters for Obtaining Product by “SHS-Electrical Rolling”

Science.gov (United States)

Aslamazashvili, Zurab; Tavadze, Giorgi; Chikhradze, Mikheil; Namicheishvili, Teimuraz; Melashvili, Zaqaria

2017-12-01

For the production materials by the proposed Self-propagating High-Temperature Synthesis (SHS) - Electric Rolling method, there are no limitations in the length of the material and the width only depends on the length of rolls. The innovation method enables to carry out the process in nonstop regime, which is possible by merging energy consuming SHS method and Electrical Rolling. For realizing the process it is mandatory and sufficient, that initial components, after initiation by thermal pulse, could interaction with the heat emission, which itself ensures the self-propagation of synthesis front in lieu of heat transfer in the whole sample. Just after that process, the rolls instantly start rotation with the set speed to ensure the motion of material. This speed should be equal to the speed of propagation of synthesis front. The synthesized product in hot plastic condition is delivered to the rolls in nonstop regime, simultaneously, providing the current in deformation zone in order to compensate the energy loses. As a result by using the innovation SHS -Electrical Rolling technology we obtain long dimensional metal-ceramic product. In the presented paper optimal compositions of SHS chasms were selected in Ti-Cr-C-Steel, Ti-B and Ti-B-Me systems. For the selection of the compounds the thermodynamic analysis has been carried out which enabled to determine adiabatic temperature of synthesis theoretically and to determine balanced concentrations of synthesized product at synthesis temperature. Thermodynamic analysis also gave possibility to determine optimal compositions of chasms and define the conditions, which are important for correct realization of synthesis process. For obtaining non porous materials and product by SHS-Electrical Rolling, it is necessary to select synthesis and compacting parameters correctly. These parameters are the pressure and the time. In Ti-Cr-C-Steel, Ti-B and Ti-B-Me systems the high quality (nonporous or low porosity values are defined

Fabrication of steel matrix composites locally reinforced with different ratios of TiC/TiB2 particulates using SHS reactions of Ni-Ti-B4C and Ni-Ti-B4C-C systems during casting

International Nuclear Information System (INIS)

Yang Yafeng; Wang Huiyuan; Liang Yunhong; Zhao Ruyi; Jiang Qichuan

2007-01-01

Steel matrix composites locally reinforced with different molar ratios of in situ TiC/TiB 2 particulates (2:1, 1:1 and 1:2, respectively) have been fabricated successfully utilizing the self-propagating high-temperature synthesis (SHS) reactions of Ni-Ti-B 4 C and Ni-Ti-B 4 C-C systems during casting. Differential thermal analysis (DTA) and X-ray diffraction (XRD) results reveal that the exothermic reactions of the Ni-Ti-B 4 C and Ni-Ti-B 4 C-C systems proceed in such a way that Ni initially reacts with B 4 C and Ti to form Ni 2 B and Ti 2 Ni compounds, respectively, with heat evolution at 1037 deg. C; Subsequently, the external heat and the evolved heat from these exothermic reactions promote the reactions forming TiC and TiB 2 at 1133 deg. C. In the composites reinforced with 1:2 molar ratio of TiC/TiB 2 , almost all TiB 2 grains have clubbed structures, while TiC grains exhibit near-spherical morphologies. Furthermore, TiB 2 grain sizes decrease, with the increase of TiC content. In particular, in the composites reinforced with 2:1 molar ratio of TiC/TiB 2 , it is difficult to find the clubbed TiB 2 grains. Macro-pores and blowholes are absent in the local reinforcing region of the composites reinforced with 1:1 and 1:2 molar ratios of TiC/TiB 2 , while a few macro-pores can be observed in the composite reinforced with 2:1 molar ratio of TiC/TiB 2 . Moreover, the densities of the composites reinforced with 1:1 and 1:2 molar ratios of TiC/TiB 2 are higher than that of the composite reinforced with 2:1 molar ratio of TiC/TiB 2 . The composite reinforced with 1:2 molar ratio of TiC/TiB 2 has the highest hardness and the best wear resistance

Reaction time for trimolecular reactions in compartment-based reaction-diffusion models

Science.gov (United States)

Li, Fei; Chen, Minghan; Erban, Radek; Cao, Yang

2018-05-01

Trimolecular reaction models are investigated in the compartment-based (lattice-based) framework for stochastic reaction-diffusion modeling. The formulae for the first collision time and the mean reaction time are derived for the case where three molecules are present in the solution under periodic boundary conditions. For the case of reflecting boundary conditions, similar formulae are obtained using a computer-assisted approach. The accuracy of these formulae is further verified through comparison with numerical results. The presented derivation is based on the first passage time analysis of Montroll [J. Math. Phys. 10, 753 (1969)]. Montroll's results for two-dimensional lattice-based random walks are adapted and applied to compartment-based models of trimolecular reactions, which are studied in one-dimensional or pseudo one-dimensional domains.

Incorporating the user perspective into a proposed model for assessing success of SHS implementations

Directory of Open Access Journals (Sweden)

Hans Holtorf

2015-10-01

Full Text Available Modern energy can contribute to development in multiple ways while approximately 20% of world's populations do not yet have access to electricity. Solar Home Systems (SHSs consists of a PV module, a charge controller and a battery supply in the range of 100 Wh/d in Sunbelt countries. The question addressed in this paper is how SHS users approach success of their systems and how these user's views can be integrated in to an existing model of success. Information was obtained on the user's approach to their SHSs by participatory observation, interviews with users and by self-observation undertaken by the lead author while residing under SHS electricity supply conditions. It was found that success of SHSs from the users' point of view is related to the ability of these systems to reduce the burdens of supplying energy services to homesteads. SHSs can alleviate some energy supply burdens, and they can improve living conditions by enabling communication on multiple levels and by addressing convenience and safety concerns. However, SHSs do not contribute to the energy services which are indispensable for survival, nor to the thermal energy services required and desired in dwellings of Sunbelt countries. The elements of three of the four components of our previously proposed model of success have been verified and found to be appropriate, namely the user's self-set goals, their importance and SHSs' success factors. The locally appropriate, and scientifically satisfactory, measurement of the level of achievement of self-set goals, the fourth component of our model of success, remains an interesting area for future research.

Microstructure and wear resistance of Al2O3-M7C3/Fe composite coatings produced by laser controlled reactive synthesis

Science.gov (United States)

Tan, Hui; Luo, Zhen; Li, Yang; Yan, Fuyu; Duan, Rui

2015-05-01

Based on the principle of thermite reaction of Al and Fe2O3 powders, the Al2O3 ceramic reinforced Fe-based composite coatings were fabricated on a steel substrate by laser controlled reactive synthesis and cladding. The effects of different additions of thermite reactants on the phase transition, microstructure evolution, microhardness and wear resistance of the composite coatings were investigated by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Vickers microhardness and block-on-ring wear test, respectively. The results show that Al2O3 ceramic and M7C3 carbide are in situ synthesized via the laser controlled reactive synthesis. The Al2O3 ceramic and M7C3 carbides prefer to distribute along the γ-Fe phase boundary continuously, which separates the γ-Fe matrix and is beneficial to the grain refinement. With the increase of thermite reactants, the amount of Al2O3 ceramic and M7C3 carbide in the composite coatings increases gradually. Moreover the cladding layer changes from dendritic structure to columnar structure and martensite structure in the heat affected zone becomes coarse. The increased thermite reactants improve the microhardness and wear resistance of the in situ composite coatings obviously and enhance the hardness of the heat affected zone, which should be ascribed to the grain refinement, ceramic and carbide precipitation and solid solution strengthening.

Production of monoclonal antibodies for Avian Metapneumovirus (SHS-BR-121) isolated in Brazil

OpenAIRE

Coswig,LT; Stach-Machado,DR; Arns,CW

2007-01-01

Avian Metapneumovirus (aMPV), also called Turkey Rhinotracheitis Virus (TRTV), is an upper respiratory tract infection of turkeys, chickens and other avian species. Five monoclonal antibodies (MAbs) were created against the Brazilian isolate (SHS-BR-121) of aMPV, MAbs 1A5B8; 1C1C4; 2C2E9 and 2A4C3 of IgG1 and MAb 1C1F8 of IgG2a. Four Mabs (1A5B8; 1C1C4; 2C2E9 and 2A4C3) showed neutralizing activity and three (1A5B8; 1C1C4 and 2A4C3) inhibited cellular fusion in vitro. These MAbs were used to ...

The Mechanical and Reaction Behavior of PTFE/Al/Fe2O3 under Impact and Quasi-Static Compression

Directory of Open Access Journals (Sweden)

Jun-yi Huang

2017-01-01

Full Text Available Quasi-static compression and drop-weight test were used to characterize the mechanical and reaction behavior of PTFE/Al/Fe2O3 composites. Two kinds of PTFE/Al/Fe2O3 composites were prepared with different mass of PTFE, and the reaction phenomenon and stress-strain curves were recorded; the residuals after reaction were analyzed by X-ray diffraction (XRD. The results showed that, under quasi-static compression condition, the strength of the materials is increased (from 37.1 Mpa to 77.2 Mpa with the increase of PTFE, and the reaction phenomenon occurred only in materials with high PTFE content. XRD analysis showed that the reaction between Al and Fe2O3 was not triggered with identical experimental conditions. In drop-weight tests, PTFE/Al/Fe2O3 specimens with low PTFE content were found to be more insensitive by high-speed photography, and a High Temperature Metal Slag Spray (HTMSS phenomenon was observed in both kinds of PTFE/Al/Fe2O3 composites, indicating the existence of thermite reaction, which was confirmed by XRD. In PTFE/Al/Fe2O3 system, the reaction between PTFE and Al precedes the reaction between Al and Fe2O3.

Experiments on the behaviour of thermite melt injected into sodium: Final report on the THINA test results

International Nuclear Information System (INIS)

Huber, F.; Kaiser, A.; Peppler, W.

1994-01-01

During hypothetical accidents of fast breeder reactors the core melts and part of the core material inventory is ejected into the upper coolant plenum. As a consequence, a fuel to coolant thermal interaction occurs between the melt and the sodium. A series of simulating experiments was carried out in KfK/IRS to improve the knowledge about the phenomenology of molten fuel/coolant interactions and to support theoretical work on the safety of fast breeder reactors. In the tests, a thermite melt of up to 3270 K is injected from below into a sodium pool the temperature of which is between 770 and 820 K. The masses of the melt and the sodium are about five and 150 kg, respectively. Thermal interactions have been observed to occur as a sequence of small local pressure events mainly during the melt injection. Large-scale vapour explosions have not been observed. Generally, the conversion ratios of thermal to mechanical energy have been low. (author)

Study of the U3O8-Al thermite reaction and strength of reactor fuel tubes

International Nuclear Information System (INIS)

Peacock, H.B.

1983-08-01

Heating tests using 53 wt % U 3 O 8 -Al pellets show that an exothermic reaction occurs between 875 and 1000 0 C and takes 10 to 20 seconds to reach maximum temperature. The maximum temperature is a function of particle size of the U 3 O 8 with large particles exhibiting lower peak temperatures. The calculated energy release was 123 cal/g of U 3 O 8 -aluminum fuel. Tests using aluminum clad outer fuel tube sections gave lower peak temperatures than for pellets. No violent reactions occurred. The results are reasonably consistent with recent reported data indicating that the exothermic U 3 O 8 -Al reaction is not an important energy source. The compressive and tensile strengths of U 3 O 8 tubes above 660 0 C are low. In compression, sections with 2 psi average axial stress failed at 917 0 C, while sections with 7 psi failed at 669 0 C. Tubes with U-Al alloy cores failed at about 670 0 C with no applied load. The stresses in fuel tubes during a reactor transient may range up to several hundred psi and are less than 7 psi only in the upper part of the fuel tube

A novel method for massive synthesis of SnO2 nanowires

Indian Academy of Sciences (India)

Compositions of three reaction systems for synthesizing SnO2 nanowires by thermite reaction. Constituents (g) ... ing voltage and at a magnification of 3000. .... nanowires to obtain the distribution shown in figure 7. SnO2 ... The Sn drop sprayed ...

Investigating Students' Reasoning about Acid-Base Reactions

Science.gov (United States)

Cooper, Melanie M.; Kouyoumdjian, Hovig; Underwood, Sonia M.

2016-01-01

Acid-base chemistry is central to a wide range of reactions. If students are able to understand how and why acid-base reactions occur, it should provide a basis for reasoning about a host of other reactions. Here, we report the development of a method to characterize student reasoning about acid-base reactions based on their description of…

Behavioral and Physiological Responses to Nicotine Patch Administration Among Nonsmokers Based on Acute and Chronic Secondhand Tobacco Smoke Exposure.

Science.gov (United States)

Okoli, Chizimuzo; Kodet, Jonathan; Robertson, Heather

2016-01-01

Despite the large amount that is known about the physical health effects of secondhand tobacco smoke (SHS) exposure, little is known about the behavioral health effects. Nicotine, the principle psychoactive substance in SHS, elicits subjective mood and physiological responses in nonsmokers. However, no studies have examined the subjective mood or physiological responses to nicotine in nonsmokers while accounting for prior chronic or acute SHS exposure. A 7-mg nicotine patch was administered to 17 adult nonsmokers for 2 hr. Main outcome measures obtained at ½ hr, 1 hr, and 2 hr were subjective behavioral drug effects (based on eleven 10-cm Visual Analog Scales [VASs]) and the physiological measures of heart rate, blood pressure, and serum nicotine levels. Analysis of outcome data was based on participants' chronic (using hair nicotine) or acute (using saliva cotinine) SHS exposure. Greater chronic SHS exposure was negatively associated with pleasurable responses to nicotine administration ("drug feels good" score at 2-hr time point, Spearman's ρ = -.65, p < .004), whereas greater acute SHS exposure was associated with positive responses ("like feeling of drug" score at 2-hr time point, Spearman's ρ = .63, p < .01). There were no associations between chronic or acute exposure and physiological changes in response to nicotine administration. The findings of this study may be useful in providing preliminary empirical data for future explorations of the mechanism whereby SHS exposure can influence behavioral outcomes in nonsmokers. Such studies can inform future interventions to reduce the physical and behavioral health risks associated with SHS exposure. © The Author(s) 2015.

Secondary organic aerosol formation from ozone-initiated reactions with nicotine and secondhand tobacco smoke

Science.gov (United States)

Sleiman, Mohamad; Destaillats, Hugo; Smith, Jared D.; Liu, Chen-Lin; Ahmed, Musahid; Wilson, Kevin R.; Gundel, Lara A.

2010-11-01

We used controlled laboratory experiments to evaluate the aerosol-forming potential of ozone reactions with nicotine and secondhand smoke. Special attention was devoted to real-time monitoring of the particle size distribution and chemical composition of SOA as they are believed to be key factors determining the toxicity of SOA. The experimental approach was based on using a vacuum ultraviolet photon ionization time-of-flight aerosol mass spectrometer (VUV-AMS), a scanning mobility particle sizer (SMPS) and off-line thermal desorption coupled to mass spectrometry (TD-GC-MS) for gas-phase byproducts analysis. Results showed that exposure of SHS to ozone induced the formation of ultrafine particles (smoke that is associated with the formation of ultrafine particles (UFP) through oxidative aging of secondhand smoke. The significance of this chemistry for indoor exposure and health effects is highlighted.

Silicon-based sleeve devices for chemical reactions

Science.gov (United States)

Northrup, M. Allen; Mariella, Jr., Raymond P.; Carrano, Anthony V.; Balch, Joseph W.

1996-01-01

A silicon-based sleeve type chemical reaction chamber that combines heaters, such as doped polysilicon for heating, and bulk silicon for convection cooling. The reaction chamber combines a critical ratio of silicon and silicon nitride to the volume of material to be heated (e.g., a liquid) in order to provide uniform heating, yet low power requirements. The reaction chamber will also allow the introduction of a secondary tube (e.g., plastic) into the reaction sleeve that contains the reaction mixture thereby alleviating any potential materials incompatibility issues. The reaction chamber may be utilized in any chemical reaction system for synthesis or processing of organic, inorganic, or biochemical reactions, such as the polymerase chain reaction (PCR) and/or other DNA reactions, such as the ligase chain reaction, which are examples of a synthetic, thermal-cycling-based reaction. The reaction chamber may also be used in synthesis instruments, particularly those for DNA amplification and synthesis.

Application of Self-Propagating High Temperature Synthesis to the Fabrication of Actinide Bearing Nitride and Other Ceramic Nuclear Fuels

International Nuclear Information System (INIS)

Moore, John J.; Reigel, Marissa M.; Donohoue, Collin D.

2009-01-01

The project uses an exothermic combustion synthesis reaction, termed self-propagating high-temperature synthesis (SHS), to produce high quality, reproducible nitride fuels and other ceramic type nuclear fuels (cercers and cermets, etc.) in conjunction with the fabrication of transmutation fuels. The major research objective of the project is determining the fundamental SHS processing parameters by first using manganese as a surrogate for americium to produce dense Zr-Mn-N ceramic compounds. These fundamental principles will then be transferred to the production of dense Zr-Am-N ceramic materials. A further research objective in the research program is generating fundamental SHS processing data to the synthesis of (i) Pu-Am-Zr-N and (ii) U-Pu-Am-N ceramic fuels. In this case, Ce will be used as the surrogate for Pu, Mn as the surrogate for Am, and depleted uranium as the surrogate for U. Once sufficient fundamental data has been determined for these surrogate systems, the information will be transferred to Idaho National Laboratory (INL) for synthesis of Zr-Am-N, Pu-Am-Zr-N and U-Pu-Am-N ceramic fuels. The high vapor pressures of americium (Am) and americium nitride (AmN) are cause for concern in producing nitride ceramic nuclear fuel that contains Am. Along with the problem of Am retention during the sintering phases of current processing methods, are additional concerns of producing a consistent product of desirable homogeneity, density and porosity. Similar difficulties have been experienced during the laboratory scale process development stage of producing metal alloys containing Am wherein compact powder sintering methods had to be abandoned. Therefore, there is an urgent need to develop a low-temperature or low-heat fuel fabrication process for the synthesis of Am-containing ceramic fuels. Self-propagating high temperature synthesis (SHS), also called combustion synthesis, offers such an alternative process for the synthesis of Am nitride fuels. Although SHS

Toward smoke-free homes: A community-based study on initiatives of rural Indian women.

Science.gov (United States)

Mittal, Srabani; Das, Samiran

2011-05-01

Since the home is the primary source of exposure of children to second-hand smoke (SHS), measures to restrict smoking at home should be introduced to protect children from its adverse health consequences. Objectives of the study were to assess the level of awareness of rural Indian women on the health impacts of SHS on children and to look into the strategies they used to reduce children's exposure to SHS at home. A community-based cross-sectional study was conducted among 438 rural women using a survey questionnaire. Information on socio-demographic characteristics, knowledge on specific health effects of SHS on children, and attitude toward having a smoke-free home were collected. The perceived reasons that made it difficult to have smoke-free homes were also explored. A total of 75.8% of women agreed that SHS was a serious health risk for children. Knowledge on health impacts of SHS on children identified asthma as the most common problem. Smoking by husbands (89.7%) was the major source of exposure to SHS at home. While 67.6% of women reported having taken measures to limit SHS exposure in their homes, only 12.8% of them had tried to introduce a complete ban on smoking at home. On a five-point evaluation scale, 73.3% of the women indicated a failure of their initiatives to have smoke-free homes. Women's initiatives to introduce restrictions on smoking at home had very limited success and did not produce an appreciable change in smoking behavior at home. Lack of empowerment of women in rural India probably rendered the interventional measures ineffective.

Toward smoke-free homes: A community-based study on initiatives of rural Indian women

Directory of Open Access Journals (Sweden)

Srabani Mittal

2011-01-01

Full Text Available Context: Since the home is the primary source of exposure of children to second-hand smoke (SHS, measures to restrict smoking at home should be introduced to protect children from its adverse health consequences. Aims: Objectives of the study were to assess the level of awareness of rural Indian women on the health impacts of SHS on children and to look into the strategies they used to reduce children′s exposure to SHS at home. Materials and Methods: A community-based cross-sectional study was conducted among 438 rural women using a survey questionnaire. Information on socio-demographic characteristics, knowledge on specific health effects of SHS on children, and attitude toward having a smoke-free home were collected. The perceived reasons that made it difficult to have smoke-free homes were also explored. Results: A total of 75.8% of women agreed that SHS was a serious health risk for children. Knowledge on health impacts of SHS on children identified asthma as the most common problem. Smoking by husbands (89.7% was the major source of exposure to SHS at home. While 67.6% of women reported having taken measures to limit SHS exposure in their homes, only 12.8% of them had tried to introduce a complete ban on smoking at home. On a five-point evaluation scale, 73.3% of the women indicated a failure of their initiatives to have smoke-free homes. Conclusions: Women′s initiatives to introduce restrictions on smoking at home had very limited success and did not produce an appreciable change in smoking behavior at home. Lack of empowerment of women in rural India probably rendered the interventional measures ineffective.

Nursing research in community-based approaches to reduce exposure to secondhand smoke.

Science.gov (United States)

Hahn, Ellen J; Ashford, Kristin B; Okoli, Chizimuzo T C; Rayens, Mary Kay; Ridner, S Lee; York, Nancy L

2009-01-01

Secondhand smoke (SHS) is the third leading cause of preventable death in the United States and a major source of indoor air pollution, accounting for an estimated 53,000 deaths per year among nonsmokers. Secondhand smoke exposure varies by gender, race/ethnicity, and socioeconomic status. The most effective public health intervention to reduce SHS exposure is to implement and enforce smoke-free workplace policies that protect entire populations including all workers regardless of occupation, race/ethnicity, gender, age, and socioeconomic status. This chapter summarizes community and population-based nursing research to reduce SHS exposure. Most of the nursing research in this area has been policy outcome studies, documenting improvement in indoor air quality, worker's health, public opinion, and reduction in Emergency Department visits for asthma, acute myocardial infarction among women, and adult smoking prevalence. These findings suggest a differential health effect by strength of law. Further, smoke-free laws do not harm business or employee turnover, nor are revenues from charitable gaming affected. Additionally, smoke-free laws may eventually have a positive effect on cessation among adults. There is emerging nursing science exploring the link between SHS exposure to nicotine and tobacco dependence, suggesting one reason that SHS reduction is a quit smoking strategy. Other nursing research studies address community readiness for smoke-free policy, and examine factors that build capacity for smoke-free policy. Emerging trends in the field include tobacco free health care and college campuses. A growing body of nursing research provides an excellent opportunity to conduct and participate in community and population-based research to reduce SHS exposure for both vulnerable populations and society at large.

Second-hand smoke exposure and the factors associated with avoidance behavior among the mothers of pre-school children: a school-based cross-sectional study

Directory of Open Access Journals (Sweden)

Lin Wei-Ting

2010-10-01

Full Text Available Abstract Background Second-hand Smoke (SHS exposure is a significant public health problem that may be responsible for serious health hazards for child. This study aimed to examine the exposure status of SHS and the factors associated with SHS avoidance behavior among the mothers of pre-school children. Methods A cross-sectional study was used to obtain a sample of the mothers of pre-school children (n = 1,020 in 30 registered kindergartens in eastern Taiwan. Overall, 919 (a response rate of 90% completed the questionnaires. Regression models were used to identify factors with respect to the avoidance behavior of SHS. Results The prevalence of exposure to SHS was 70% and 50% for the mothers and their children, respectively. After adjusting for other variables, mothers who were current smokers (β = -0.260, p Conclusions The high prevalence rate of exposure to SHS for mothers and their children suggests that a well-designed future intervention program should be implemented in regard to pre-school children's mothers in order to prevent these mothers and their children from SHS exposure hazards, more particularly, to strengthen the knowledge base, to enhance self-efficacy and to foster a more positive attitude toward the avoidance of SHS in the mothers.

In situ spectroscopy of ligand exchange reactions at the surface of colloidal gold and silver nanoparticles

International Nuclear Information System (INIS)

Dinkel, Rebecca; Peukert, Wolfgang; Braunschweig, Björn

2017-01-01

Gold and silver nanoparticles with their tunable optical and electronic properties are of great interest for a wide range of applications. Often the ligands at the surface of the nanoparticles have to be exchanged in a second step after particle formation in order to obtain a desired surface functionalization. For many techniques, this process is not accessible in situ . In this review, we present second-harmonic scattering (SHS) as an inherently surface sensitive and label-free optical technique to probe the ligand exchange at the surface of colloidal gold and silver nanoparticles in situ and in real time. First, a brief introduction to SHS and basic features of the SHS of nanoparticles are given. After that, we demonstrate how the SHS intensity decrease can be correlated to the thiol coverage which allows for the determination of the Gibbs free energy of adsorption and the surface coverage. (topical review)

Influence of compaction pressure on the morphology and phase evolution of porous NiTi alloy prepared by SHS technique

Directory of Open Access Journals (Sweden)

Sirikul Wisutmethangoon

2008-08-01

Full Text Available The influence of compaction pressure on the pore morphology of porous NiTi shape memory alloys (SMAs fabricated by self-propagating high-temperature synthesis (SHS was investigated. The compaction pressure has a significant effect on the combustion temperature and pore morphology. The porous NiTi (SMAs thus obtained have the porosity of product in the range of 37.4-57.9 vol.%. The open porosity ratios were observed to be greater than 88%, which indicatesthat porous NiTi (SMAs are suitable for biomedical applications. In addition, the predominant phases in the porous product are B2(NiTi and B19’(NiTi with small amounts of secondary phases, NiTi2 and Ni4Ti3.

Isocyanide based multi component reactions in combinatorial chemistry.

NARCIS (Netherlands)

Dömling, A.

1998-01-01

Although usually regarded as a recent development, the combinatorial approach to the synthesis of libraries of new drug candidates was first described as early as 1961 using the isocyanide-based one-pot multicomponent Ugi reaction. Isocyanide-based multi component reactions (MCR's) markedly differ

Proceedings of the international meeting on research and test reactor core conversions from HEU to LEU fuels

International Nuclear Information System (INIS)

1983-09-01

Separate abstracts have been prepared for each paper presented in the following areas of interest: (1) fuel development; (2) post-irradiation examinations; (3) reprocessing; (4) thermite reaction; (5) fuel fabrication; (6) element tests; (7) core tests; (8) criticals; (9) shipping; and (10) reactors and methods

An assessment of the process of Self-propagating High-Temperature Synthesis for the fabrication of porous copper composite

International Nuclear Information System (INIS)

Moloodi, A.; Raiszadeh, R.; Vahdati-Khaki, J.; Babakhani, A.

2009-01-01

The present article describes the process of Self-propagating High-temperature Synthesis (SHS) that is employed for fabricating open cell copper-alumina composite foam. This foam was fabricated by the reactions between the powders of CuO, Al and C. The gas released during these reactions as well as the initial porosity of the green powder compact were suggested to be the sources of the produced pores. Further, the effect of C content and the precursor compressing pressure on the porosity content and morphology of the SHS product was determined. Optical microscopy (OM), scanning electron microscopy (SEM), and X-ray diffraction (XRD) were utilized to characterize the porous samples. The optimum weight fractions for blending the initial powders were determined to be 84 wt.% CuO, 9.5 wt.% Al, and 6.5 wt.% C, and the SHS reaction was sustainable only if the initial compacting pressure of the powders was between 100 and 300 MPa.

Elucidating the hard/soft acid/base principle: A perspective based on half-reactions

International Nuclear Information System (INIS)

Ayers, Paul W.; Parr, Robert G.; Pearson, Ralph G.

2006-01-01

A comprehensive analysis is presented for the acid-base double-exchange reaction as well as the associated acid-displacement and base-displacement 'half-reactions' with the goal of elucidating the meaning of the hard/soft acid/base (HSAB) principle and the conditions for its validity. When electron-transfer effects are important and other effects are negligible, the HSAB principle is driven by the surpassing stability of the soft acid/soft base product. When electrostatic effects dominate the reactivity, the HSAB principle is driven by the surpassing stability of the hard acid/hard base product. Because electron-transfer effects favor soft/soft interactions, while electrostatic effects favor hard/hard interactions, acid-base exchange reactions may be used to determine whether a reagent's reactivity is dominated by electron-transfer or by electrostatic effects. Because electron-transfer and electrostatic considerations separately favor the HSAB principle whenever the electronic chemical potentials of the acids and bases involved in the reaction are similar, our analysis provides strong support for the HSAB principle. The electronic chemical potential measures the intrinsic strength of acids and bases

Evaporated self-supporting foils of enriched iron from the in-situ reduction of Fe2O3

International Nuclear Information System (INIS)

Riel, W.D.

1976-01-01

This paper describes the reduction of isotopically enriched Fe 2 O 3 usng a controlled thermite reaction. The method will produce strain free evaporated films of 100-300 μg/cm 2 which can be floated and mounted, using standard techniques, to make strong self-supporting targets. (author)

Rule-Based Event Processing and Reaction Rules

Science.gov (United States)

Paschke, Adrian; Kozlenkov, Alexander

Reaction rules and event processing technologies play a key role in making business and IT / Internet infrastructures more agile and active. While event processing is concerned with detecting events from large event clouds or streams in almost real-time, reaction rules are concerned with the invocation of actions in response to events and actionable situations. They state the conditions under which actions must be taken. In the last decades various reaction rule and event processing approaches have been developed, which for the most part have been advanced separately. In this paper we survey reaction rule approaches and rule-based event processing systems and languages.

Micro-chip initiator realized by integrating Al/CuO multilayer nanothermite on polymeric membrane

International Nuclear Information System (INIS)

Taton, G; Lagrange, D; Conedera, V; Rossi, C; Renaud, L

2013-01-01

We have developed a new nanothermite based polymeric electro-thermal initiator for non-contact ignition of a propellant. A reactive Al/CuO multilayer nanothermite resides on a 100 µm thick SU-8/PET (polyethyleneterephtalate) membrane to insulate the reactive layer from the silicon bulk substrate. When current is supplied to the initiator, the chemical reaction Al+CuO occurs and sparkles are spread to a distance of several millimeters. A micro-manufacturing process for fabricating the initiator is presented and the electrical behaviors of the ignition elements are also investigated. The characteristics of the initiator made on a 100 µm thick SU-8/PET membrane were compared to two bulk electro-thermal initiators: one on a silicon and one on a Pyrex substrate. The PET devices give 100% of Al/CuO ignition success for an electrical current >250 mA. Glass based reactive initiators give 100% of Al/CuO ignition success for an electrical current >500 mA. Reactive initiators directly on silicon cannot initiate even with a 4 A current. At low currents (<1 A), the initiation time is two orders of magnitude longer for Pyrex initiator compared to those obtained for PET initiator technology. We also observed that, the Al/CuO thermite film on PET membrane reacts within 1 ms (sparkles duration) whereas it reacts within 4 ms on Pyrex. The thermite reaction is 40 times greater in intensity using the PET substrate in comparison to Pyrex. (paper)

Secondhand Smoke Exposure and Low Blood Lead Levels in Association With Attention-Deficit Hyperactivity Disorder and Its Symptom Domain in Children: A Community-Based Case-Control Study.

Science.gov (United States)

Joo, Hyunjoo; Lim, Myung-Ho; Ha, Mina; Kwon, Ho-Jang; Yoo, Seung Jin; Choi, Kyung-Hwa; Paik, Ki-Chung

2017-01-01

Secondhand smoke (SHS) is a major indoor pollutant. We examined the possible association between exposure to both SHS and low levels of lead and attention-deficit-hyperactivity disorder (ADHD) and its symptom domain in children. This case-control study was based on the results of a community survey using the ADHD rating scale conducted in 49 elementary schools. Both cases and control subjects were confirmed by a child psychiatrist. Each case was matched with one control subject according to gender, school, and grade in school. Using a multivariate conditional logistic regression model, we analyzed 214 case-control pairs of children who ranged in age from 6 to 10 years. Urine and blood levels of cotinine and of lead were determined, and information pertaining to SHS exposure was obtained by means of a questionnaire. Exposure to low levels of lead (geometric mean = 1.65 µg/dL) was related to ADHD, particularly inattention (odds ratio [OR] = 1.67, 95% confidence interval [CI] = 1.07-2.59), whereas SHS exposure was associated mainly with hyperactivity/impulsivity (OR = 3.85, 95% CI = 1.55-9.56). In the pathway from blood lead to hyperactivity/impulsivity, children's SHS exposure mediated and indirectly accounted for about 73% of this relationship. The combined exposure to lead and SHS synergistically increased the risk of ADHD, evident as both inattention and hyperactivity/impulsivity. SHS, which is associated with hyperactivity/impulsivity in particular, combined with exposure to low blood levels of lead synergistically increased the risk of ADHD. Therefore, the exposure of children to both SHS and lead needs to be reduced. Although exposure to low levels of lead has been shown to be associated with ADHD, there is little evidence of symptom domain specificity. In our study, low blood lead levels were related to inattention. In addition, prenatal or postnatal exposure to SHS increased the risk of ADHD, particularly hyperactivity/impulsivity. Combined exposure to lead

SIMBATH 1976-1992, seventeen years of experimental investigation of key issues concerned with severe reactor accidents

International Nuclear Information System (INIS)

Kaiser, A.; Peppler, W.; Will, H.

1994-01-01

The course of the initiating phase of severe fast reactor accidents is determined by early material motion. In simulation experiments (SIMBATH, simulation experiments in fuel element mock-ups with thermite) the behavior of single pin, 7 pin, 19 pin, 37 pin bundles undergoing meltdown was investigated. Thermite (Al + Fe 2 O 3 ) filled tubes were used to simulate fuel rods, while exothermal heat of the thermite reaction simulated the nuclear heat. The energy of 3.4 kJ per centimeter of pin length resulted in melting temperature of about 3200 K. SIMBATH is an out-of-pile experimental program with non-radioactive materials which provided the possibility to perform numerous experiments. The x-ray high speed photography used in the test enabled to visualise material motion and relocation qualitatively, and furthermore to gain quantitative results by additionally installed photodiodes. The results of the experiment serve as a database to evaluate physical phenomena relevant to be modelled by computer codes (SIMMER) and to verify the codes. The experiments were carried out either in stagnant sodium with an axial temperature gradient, or in flowing sodium, simulating unprotected loss of flow (ULOF) or unprotected transient overpower accidents (UTOP) conditions, respectively

Reaction paths based on mean first-passage times

International Nuclear Information System (INIS)

Park, Sanghyun; Sener, Melih K.; Lu Deyu; Schulten, Klaus

2003-01-01

Finding representative reaction pathways is important for understanding the mechanism of molecular processes. We propose a new approach for constructing reaction paths based on mean first-passage times. This approach incorporates information about all possible reaction events as well as the effect of temperature. As an application of this method, we study representative pathways of excitation migration in a photosynthetic light-harvesting complex, photosystem I. The paths thus computed provide a complete, yet distilled, representation of the kinetic flow of excitation toward the reaction center, thereby succinctly characterizing the function of the system

Accelerating rejection-based simulation of biochemical reactions with bounded acceptance probability

Energy Technology Data Exchange (ETDEWEB)

Thanh, Vo Hong, E-mail: vo@cosbi.eu [The Microsoft Research - University of Trento Centre for Computational and Systems Biology, Piazza Manifattura 1, Rovereto 38068 (Italy); Priami, Corrado, E-mail: priami@cosbi.eu [The Microsoft Research - University of Trento Centre for Computational and Systems Biology, Piazza Manifattura 1, Rovereto 38068 (Italy); Department of Mathematics, University of Trento, Trento (Italy); Zunino, Roberto, E-mail: roberto.zunino@unitn.it [Department of Mathematics, University of Trento, Trento (Italy)

2016-06-14

Stochastic simulation of large biochemical reaction networks is often computationally expensive due to the disparate reaction rates and high variability of population of chemical species. An approach to accelerate the simulation is to allow multiple reaction firings before performing update by assuming that reaction propensities are changing of a negligible amount during a time interval. Species with small population in the firings of fast reactions significantly affect both performance and accuracy of this simulation approach. It is even worse when these small population species are involved in a large number of reactions. We present in this paper a new approximate algorithm to cope with this problem. It is based on bounding the acceptance probability of a reaction selected by the exact rejection-based simulation algorithm, which employs propensity bounds of reactions and the rejection-based mechanism to select next reaction firings. The reaction is ensured to be selected to fire with an acceptance rate greater than a predefined probability in which the selection becomes exact if the probability is set to one. Our new algorithm improves the computational cost for selecting the next reaction firing and reduces the updating the propensities of reactions.

In Situ Imaging of Particle Formation and Dynamics in Reactive Material Deflagrations

Energy Technology Data Exchange (ETDEWEB)

Sullivan, Kyle T. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

2016-12-12

Reactive composites utilizing nanoparticles have been the topic of extensive research in the past two decades. The driver for this is that, as the particle size is decreased, the mixing scale between constituents is greatly reduced, which has long thought to increase the rate of chemical reaction. While a general trend of increased reactivity has been seen for metal / metal oxide, or thermite, reactive materials, some results have demonstrated diminishing returns as the particle size is further decreased. Recent results have shown that nanoparticles, which are typically aggregates of several primary particles, can undergo very rapid coalescence to form micron particles once a critical temperature is reached. Experiments on this topic to date have been performed on very small sample masses, and sometimes under vacuum; conditions which are not representative of the environment during a deflagration. In this feasibility study, a custom burn tube was used to ignite and react 100 mg powdered thermite samples in long acrylic tubes. X-ray imaging at APS Sector 32 was performed to image the particle field as a function of distance and time as the rarefied particle cloud expanded and flowed down the tube. Five different thermite formulations were investigated, Al / CuO, Al / Fe₂O₃, Al / SnO₂, Al / WO₃, and Al / Fe₂O₃, along with Al / CuO formulations with different sizes of Al particles ranging from 80 nm to approximate 10 μm. The results clearly show that the sample powder reacts and unloads into a distribution of larger micron-scale particles (~5-500 μm), which continue to react and propagate as the particle-laden stream flows down the tube. This was the first direct imaging of the particle field during a thermite deflagration, and gives significant insight into the evolution of reactants to products. Analysis of phase is currently being pursued to determine whether this method can be used to extract

Wang-Landau Reaction Ensemble Method: Simulation of Weak Polyelectrolytes and General Acid-Base Reactions.

Science.gov (United States)

Landsgesell, Jonas; Holm, Christian; Smiatek, Jens

2017-02-14

We present a novel method for the study of weak polyelectrolytes and general acid-base reactions in molecular dynamics and Monte Carlo simulations. The approach combines the advantages of the reaction ensemble and the Wang-Landau sampling method. Deprotonation and protonation reactions are simulated explicitly with the help of the reaction ensemble method, while the accurate sampling of the corresponding phase space is achieved by the Wang-Landau approach. The combination of both techniques provides a sufficient statistical accuracy such that meaningful estimates for the density of states and the partition sum can be obtained. With regard to these estimates, several thermodynamic observables like the heat capacity or reaction free energies can be calculated. We demonstrate that the computation times for the calculation of titration curves with a high statistical accuracy can be significantly decreased when compared to the original reaction ensemble method. The applicability of our approach is validated by the study of weak polyelectrolytes and their thermodynamic properties.

Automatic NMR-based identification of chemical reaction types in mixtures of co-occurring reactions.

Science.gov (United States)

Latino, Diogo A R S; Aires-de-Sousa, João

2014-01-01

The combination of chemoinformatics approaches with NMR techniques and the increasing availability of data allow the resolution of problems far beyond the original application of NMR in structure elucidation/verification. The diversity of applications can range from process monitoring, metabolic profiling, authentication of products, to quality control. An application related to the automatic analysis of complex mixtures concerns mixtures of chemical reactions. We encoded mixtures of chemical reactions with the difference between the (1)H NMR spectra of the products and the reactants. All the signals arising from all the reactants of the co-occurring reactions were taken together (a simulated spectrum of the mixture of reactants) and the same was done for products. The difference spectrum is taken as the representation of the mixture of chemical reactions. A data set of 181 chemical reactions was used, each reaction manually assigned to one of 6 types. From this dataset, we simulated mixtures where two reactions of different types would occur simultaneously. Automatic learning methods were trained to classify the reactions occurring in a mixture from the (1)H NMR-based descriptor of the mixture. Unsupervised learning methods (self-organizing maps) produced a reasonable clustering of the mixtures by reaction type, and allowed the correct classification of 80% and 63% of the mixtures in two independent test sets of different similarity to the training set. With random forests (RF), the percentage of correct classifications was increased to 99% and 80% for the same test sets. The RF probability associated to the predictions yielded a robust indication of their reliability. This study demonstrates the possibility of applying machine learning methods to automatically identify types of co-occurring chemical reactions from NMR data. Using no explicit structural information about the reactions participants, reaction elucidation is performed without structure elucidation of

Automatic NMR-based identification of chemical reaction types in mixtures of co-occurring reactions.

Directory of Open Access Journals (Sweden)

Diogo A R S Latino

Full Text Available The combination of chemoinformatics approaches with NMR techniques and the increasing availability of data allow the resolution of problems far beyond the original application of NMR in structure elucidation/verification. The diversity of applications can range from process monitoring, metabolic profiling, authentication of products, to quality control. An application related to the automatic analysis of complex mixtures concerns mixtures of chemical reactions. We encoded mixtures of chemical reactions with the difference between the (1H NMR spectra of the products and the reactants. All the signals arising from all the reactants of the co-occurring reactions were taken together (a simulated spectrum of the mixture of reactants and the same was done for products. The difference spectrum is taken as the representation of the mixture of chemical reactions. A data set of 181 chemical reactions was used, each reaction manually assigned to one of 6 types. From this dataset, we simulated mixtures where two reactions of different types would occur simultaneously. Automatic learning methods were trained to classify the reactions occurring in a mixture from the (1H NMR-based descriptor of the mixture. Unsupervised learning methods (self-organizing maps produced a reasonable clustering of the mixtures by reaction type, and allowed the correct classification of 80% and 63% of the mixtures in two independent test sets of different similarity to the training set. With random forests (RF, the percentage of correct classifications was increased to 99% and 80% for the same test sets. The RF probability associated to the predictions yielded a robust indication of their reliability. This study demonstrates the possibility of applying machine learning methods to automatically identify types of co-occurring chemical reactions from NMR data. Using no explicit structural information about the reactions participants, reaction elucidation is performed without structure

Financing of Solar Home Systems (SHS); Finanzierung von Solar Home Systemen. Erfahrungen aus der Praxis

Energy Technology Data Exchange (ETDEWEB)

Adelmann, P.; Rimpler, G.; Zimmermann, A. [Phocos AG, Ulm (Germany)

2005-07-01

In many cases Solar Systems are the cheapest option for rural electrification. Often the users spend every month a quite high amount of money for dry cell batteries, kerosene and candles to supply a radio or to have light. Problem is that the users can spend a certain amount every month, but they are not able to have the necessary investment for a SHS at one. Financing would be requires. There are different ways to finance the solar home systems. In some cases the user has to pay a fee for the service. In these cases the investor is the owner of the system. In other cases a microcredit is given to the user. His then the owner of the system and responsible for any losses in the system. An interesting model is a battery charging station. In this model it is possible for the user to become step by step owner of a solar system. Conclusion. Fee for service systems did not perform perfectly. Main reason is the missing responsibility of the user for any damage. Microcredits did perform well in several places in Asia. A interesting option for the future are battery charging stations. This model hashighest flexibility in financing. It can be adopted at any moment to the abilities of the user. (orig.)

Overview of Light Hydrogen-Based Low Energy Nuclear Reactions

Science.gov (United States)

Miley, George H.; Shrestha, Prajakti J.

This paper reviews light water and hydrogen-based low-energy nuclear reactions (LENRs) including the different methodologies used to study these reactions and the results obtained. Reports of excess heat production, transmutation reactions, and nuclear radiation emission are cited. An aim of this review is to present a summary of the present status of light water LENR research and provide some insight into where this research is heading.

Self-propagating high-temperature synthesis of nonstoichiometric wuestite

Energy Technology Data Exchange (ETDEWEB)

Hiramoto, Maki [Graduate School of Engineering, Hokkaido University, Sapporo 060-8628 (Japan); Okinaka, Noriyuki [Center for Advanced Research of Energy and Materials, Faculty of Engineering, Hokkaido University, Sapporo 060-8628 (Japan); Akiyama, Tomohiro, E-mail: takiyama@eng.hokudai.ac.jp [Center for Advanced Research of Energy and Materials, Faculty of Engineering, Hokkaido University, Sapporo 060-8628 (Japan)

2012-04-15

Highlights: Black-Right-Pointing-Pointer The manuscript describes an SHS method of producing Fe{sub x}O. Black-Right-Pointing-Pointer Focus on the effects of nonstoichiometric Fe content and diluent addition on the phase of the SHS product. Black-Right-Pointing-Pointer Without the NaCl diluent, the lattice parameter of SHS Fe{sub 0.947}O corresponded to the theoretical lattice parameter. Black-Right-Pointing-Pointer Nonstoichiometric compounds of Fe{sub x}O (0.942 {<=} x {<=} 0.952) were obtained through SHS without additional external heating. - Abstract: This paper describes the self-propagating high-temperature synthesis (SHS) of nonstoichiometric Fe{sub x}O (x = 0.833-1), with particular focus on the effects of nonstoichiometric Fe content and diluent addition on the phase of the SHS product. In the SHS process, the raw materials Fe, NaClO{sub 4} (oxidizer), and NaCl (diluent) were thoroughly mixed in the desired ratio by ball milling, and the lower surfaces of the disk-shaped green compacts were subsequently electrically ignited to produce Fe{sub x}O through the propagation of the sustainable exothermic reaction. X-ray diffraction analysis showed that the SHS products comprised double phases of Fe{sub x}O and Fe{sub 3}O{sub 4}. The peaks of products with 0.947 {<=} x {<=} 1.00 shifted to lower angles in comparison to those of the product with x = 0.833 attributed to the lattice parameter distortion of the crystal structure because of the Fe defects. In the presence of the NaCl diluent, the raw materials were converted to high-purity Fe{sub x}O powders during the SHS process. Without the NaCl diluent, the lattice parameter of SHS Fe{sub 0.947}O corresponded to the theoretical lattice parameter. Nonstoichiometric compounds of Fe{sub x}O (0.942 {<=} x {<=} 0.952) were obtained through SHS without additional external heating.

Glider-based computing in reaction-diffusion hexagonal cellular automata

International Nuclear Information System (INIS)

Adamatzky, Andrew; Wuensche, Andrew; De Lacy Costello, Benjamin

2006-01-01

A three-state hexagonal cellular automaton, discovered in [Wuensche A. Glider dynamics in 3-value hexagonal cellular automata: the beehive rule. Int J Unconvention Comput, in press], presents a conceptual discrete model of a reaction-diffusion system with inhibitor and activator reagents. The automaton model of reaction-diffusion exhibits mobile localized patterns (gliders) in its space-time dynamics. We show how to implement the basic computational operations with these mobile localizations, and thus demonstrate collision-based logical universality of the hexagonal reaction-diffusion cellular automaton

An MHD heat source based on intermetallic reactions

Energy Technology Data Exchange (ETDEWEB)

Sadjian, H.; Zavitsanos, P. (General Sciences, Inc., Souderton, PA (United States)); Marston, C.H. (Villanova Univ., PA (United States))

1991-05-06

The main objective of this program was the development of an MHD heat source of potential use in Space - Based Multi Megawatt, MHD Power Systems. The approach is based on extension of high temperature chemical/ion release technology developed by the General Sciences, Incorporated (GSI) team and successfully applied in other Space Applications. Solid state reactions have been identified which can deliver energy densities and electrons in excess of those from high energy explosives as well as other conventional fuels. The use of intermetallic reactions can be used to generate hot hydrogen plasma from the reaction, to create a high level of seedant ionization, can be packaged as a cartridge type fuels for discrete pulses. The estimated weight for energizing a (100 MW - 1000 sec) Pulsed MHD Power System can range from 12 to 25 {times} 10{sup 3} kg depending on reaction system and strength of the magnetic field. The program consisted of two major tasks with eight subtasks designed to systematically evaluate these concepts in order to reduce fuel weight requirements. Laboratory measurements on energy release, reaction product identification and levels of ionization were conducted in the first task to screen candidate fuels. The second task addressed the development of a reaction chamber in which conductivity, temperature and pressure were measured. Instrumentation was developed to measure these parameters under high temperature pulsed conditions in addition to computer programs to reduce the raw data. Measurements were conducted at GSI laboratories for fuel weights of up to 120 grams and at the Franklin Research Center* for fuel weights up to 1 kilogram. The results indicate that fuel weight can be scaled using modular packaging. Estimates are presented for fuel weight requirements. 15 refs.

COEL: A Cloud-based Reaction Network Simulator

Directory of Open Access Journals (Sweden)

Peter eBanda

2016-04-01

Full Text Available Chemical Reaction Networks (CRNs are a formalism to describe the macroscopic behavior of chemical systems. We introduce COEL, a web- and cloud-based CRN simulation framework that does not require a local installation, runs simulations on a large computational grid, provides reliable database storage, and offers a visually pleasing and intuitive user interface. We present an overview of the underlying software, the technologies, and the main architectural approaches employed. Some of COEL's key features include ODE-based simulations of CRNs and multicompartment reaction networks with rich interaction options, a built-in plotting engine, automatic DNA-strand displacement transformation and visualization, SBML/Octave/Matlab export, and a built-in genetic-algorithm-based optimization toolbox for rate constants.COEL is an open-source project hosted on GitHub (http://dx.doi.org/10.5281/zenodo.46544, which allows interested research groups to deploy it on their own sever. Regular users can simply use the web instance at no cost at http://coel-sim.org. The framework is ideally suited for a collaborative use in both research and education.

Overview of light water/hydrogen-based low energy nuclear reactions

International Nuclear Information System (INIS)

Miley, George H.; Shrestha, Prajakti J.

2006-01-01

This paper reviews light water and hydrogen-based low-energy nuclear reactions (LENRs) including the different methodologies used to study these reactions and the results obtained. Reports of excess heat production, transmutation reactions, and nuclear radiation emission are cited. An aim of this review is to present a summary of the present status of light water LENR research and provide some insight into where this research is heading. (author)

A simple thermometric technique for reaction-rate determination of inorganic species, based on the iodide-catalysed cerium(IV)-arsenic(III) reaction.

Science.gov (United States)

Grases, F; Forteza, R; March, J G; Cerda, V

1985-02-01

A very simple reaction-rate thermometric technique is used for determination of iodide (5-20 ng ml ), based on its catalytic action on the cerium(IV)-arsenic(III) reaction, and for determination of mercury(II) (1.5-10 ng ml ) and silver(I) (2-10 ng ml ), based on their inhibitory effect on this reaction. The reaction is followed by measuring the rate of temperature increase. The method suffers from very few interferences and is applied to determination of iodide in biological and inorganic samples, and Hg(II) and Ag(I) in pharmaceutical products.

Simulation of biochemical reactions with time-dependent rates by the rejection-based algorithm

Energy Technology Data Exchange (ETDEWEB)

Thanh, Vo Hong, E-mail: vo@cosbi.eu [The Microsoft Research - University of Trento Centre for Computational and Systems Biology, Piazza Manifattura 1, Rovereto 38068 (Italy); Priami, Corrado, E-mail: priami@cosbi.eu [The Microsoft Research - University of Trento Centre for Computational and Systems Biology, Piazza Manifattura 1, Rovereto 38068 (Italy); Department of Mathematics, University of Trento, Trento (Italy)

2015-08-07

We address the problem of simulating biochemical reaction networks with time-dependent rates and propose a new algorithm based on our rejection-based stochastic simulation algorithm (RSSA) [Thanh et al., J. Chem. Phys. 141(13), 134116 (2014)]. The computation for selecting next reaction firings by our time-dependent RSSA (tRSSA) is computationally efficient. Furthermore, the generated trajectory is exact by exploiting the rejection-based mechanism. We benchmark tRSSA on different biological systems with varying forms of reaction rates to demonstrate its applicability and efficiency. We reveal that for nontrivial cases, the selection of reaction firings in existing algorithms introduces approximations because the integration of reaction rates is very computationally demanding and simplifying assumptions are introduced. The selection of the next reaction firing by our approach is easier while preserving the exactness.

Structure-reactivity modeling using mixture-based representation of chemical reactions.

Science.gov (United States)

Polishchuk, Pavel; Madzhidov, Timur; Gimadiev, Timur; Bodrov, Andrey; Nugmanov, Ramil; Varnek, Alexandre

2017-09-01

We describe a novel approach of reaction representation as a combination of two mixtures: a mixture of reactants and a mixture of products. In turn, each mixture can be encoded using an earlier reported approach involving simplex descriptors (SiRMS). The feature vector representing these two mixtures results from either concatenated product and reactant descriptors or the difference between descriptors of products and reactants. This reaction representation doesn't need an explicit labeling of a reaction center. The rigorous "product-out" cross-validation (CV) strategy has been suggested. Unlike the naïve "reaction-out" CV approach based on a random selection of items, the proposed one provides with more realistic estimation of prediction accuracy for reactions resulting in novel products. The new methodology has been applied to model rate constants of E2 reactions. It has been demonstrated that the use of the fragment control domain applicability approach significantly increases prediction accuracy of the models. The models obtained with new "mixture" approach performed better than those required either explicit (Condensed Graph of Reaction) or implicit (reaction fingerprints) reaction center labeling.

Microwave scattering coefficient of snow in MEMLS and DMRT-ML revisited: the relevance of sticky hard spheres and tomography-based estimates of stickiness

Directory of Open Access Journals (Sweden)

H. Löwe

2015-11-01

Full Text Available The description of snow microstructure in microwave models is often simplified to facilitate electromagnetic calculations. Within dense media radiative transfer (DMRT, the microstructure is commonly described by sticky hard spheres (SHS. An objective mapping of real snow onto SHS is however missing which prevents measured input parameters from being used for DMRT. In contrast, the microwave emission model of layered snowpacks (MEMLS employs a conceptually different approach, based on the two-point correlation function which is accessible by tomography. Here we show the equivalence of both electromagnetic approaches by reformulating their microstructural models in a common framework. Using analytical results for the two-point correlation function of hard spheres, we show that the scattering coefficient in both models only differs by a factor which is close to unity, weakly dependent on ice volume fraction and independent of other microstructural details. Additionally, our analysis provides an objective retrieval method for the SHS parameters (diameter and stickiness from tomography images. For a comprehensive data set we demonstrate the variability of stickiness and compare the SHS diameter to the optical equivalent diameter. Our results confirm the necessity of a large grain-size scaling when relating both diameters in the non-sticky case, as previously suggested by several authors.

A reaction-based paradigm to model reactive chemical transport in groundwater with general kinetic and equilibrium reactions

International Nuclear Information System (INIS)

Zhang, Fan; Yeh, Gour-Tsyh; Parker, Jack C.; Brooks, Scott C; Pace, Molly; Kim, Young Jin; Jardine, Philip M.; Watson, David B.

2007-01-01

This paper presents a reaction-based water quality transport model in subsurface flow systems. Transport of chemical species with a variety of chemical and physical processes is mathematically described by M. partial differential equations (PDEs). Decomposition via Gauss-Jordan column reduction of the reaction network transforms M. species reactive transport equations into two sets of equations: a set of thermodynamic equilibrium equations representing NE equilibrium reactions and a set of reactive transport equations of M-NE kinetic-variables involving no equilibrium reactions (a kinetic-variable is a linear combination of species). The elimination of equilibrium reactions from reactive transport equations allows robust and efficient numerical integration. The model solves the PDEs of kinetic-variables rather than individual chemical species, which reduces the number of reactive transport equations and simplifies the reaction terms in the equations. A variety of numerical methods are investigated for solving the coupled transport and reaction equations. Simulation comparisons with exact solutions were performed to verify numerical accuracy and assess the effectiveness of various numerical strategies to deal with different application circumstances. Two validation examples involving simulations of uranium transport in soil columns are presented to evaluate the ability of the model to simulate reactive transport with complex reaction networks involving both kinetic and equilibrium reactions

A reaction-based paradigm to model reactive chemical transport in groundwater with general kinetic and equilibrium reactions.

Science.gov (United States)

Zhang, Fan; Yeh, Gour-Tsyh; Parker, Jack C; Brooks, Scott C; Pace, Molly N; Kim, Young-Jin; Jardine, Philip M; Watson, David B

2007-06-16

This paper presents a reaction-based water quality transport model in subsurface flow systems. Transport of chemical species with a variety of chemical and physical processes is mathematically described by M partial differential equations (PDEs). Decomposition via Gauss-Jordan column reduction of the reaction network transforms M species reactive transport equations into two sets of equations: a set of thermodynamic equilibrium equations representing N(E) equilibrium reactions and a set of reactive transport equations of M-N(E) kinetic-variables involving no equilibrium reactions (a kinetic-variable is a linear combination of species). The elimination of equilibrium reactions from reactive transport equations allows robust and efficient numerical integration. The model solves the PDEs of kinetic-variables rather than individual chemical species, which reduces the number of reactive transport equations and simplifies the reaction terms in the equations. A variety of numerical methods are investigated for solving the coupled transport and reaction equations. Simulation comparisons with exact solutions were performed to verify numerical accuracy and assess the effectiveness of various numerical strategies to deal with different application circumstances. Two validation examples involving simulations of uranium transport in soil columns are presented to evaluate the ability of the model to simulate reactive transport with complex reaction networks involving both kinetic and equilibrium reactions.

ECO steam explosion experiments on the conversion of thermal into mechanical energy

International Nuclear Information System (INIS)

Cherdron, W.; Kaiser, A.; Schuetz, W.; Will, H.

2001-01-01

In case of a steam explosion, e.g. as a consequence of a severe reactor accident, part of the thermal energy of the melt is transferred into mechanical energy. At Forschungszentrum Karlsruhe, so-called ECO experiments, are being directed to measure the conversion factor under well-defined conditions. In ECO, alumina from a thermite reaction is used as a simulating material instead of corium. Dimensions of the test facility as well as major test conditions, e.g. temperature and release mode of the melt, water inventory and test procedure, are based on the former PREMIX experimental series. In the paper, results of the first test, ECO 01, are given. (orig.)

Response to Thermal Exposure of Ball-Milled Aluminum-Borax Powder Blends

Science.gov (United States)

Birol, Yucel

2013-04-01

Aluminum-borax powder mixtures were ball milled and heated above 873 K (600 °C) to produce Al-B master alloys. Ball-milled powder blends reveal interpenetrating layers of deformed aluminum and borax grains that are increasingly refined with increasing milling time. Thermal exposure of the ball-milled powder blends facilitates a series of thermite reactions between these layers. Borax, dehydrated during heating, is reduced by Al, and B thus generated reacts with excess Al to produce AlB2 particles dispersed across the aluminum grains starting at 873 K (600 °C). AlB2 particles start to form along the interface of the aluminum and borax layers. Once nucleated, these particles grow readily to become hexagonal-shaped crystals that traverse the aluminum grains with increasing temperatures as evidenced by the increase in the size as well as in the number of the AlB2 particles. Ball milling for 1 hour suffices to achieve a thermite reaction between borax and aluminum. Ball milling further does not impact the response of the powder blend to thermal exposure. The nucleation-reaction sites are multiplied, however, with increasing milling time and thus insure a higher number of smaller AlB2 particles. The size of the AlB2 platelets may be adjusted with the ball milling time.

Affecting Factors of Secondhand Smoke Exposure in Korea: Focused on Different Exposure Locations.

Science.gov (United States)

Sun, Li Yuan; Cheong, Hae Kwan; Lee, Eun Whan; Kang, Kyeong Jin; Park, Jae Hyun

2016-09-01

Exposure to secondhand smoke (SHS) not only can cause serious illness, but is also an economic and social burden. Contextual and individual factors of non-smoker exposure to SHS depend on location. However, studies focusing on this subject are lacking. In this study, we described and compared the factors related to SHS exposure according to location in Korea. Regarding individual factors related to SHS exposure, a common individual variable model and location-specific variable model was used to evaluate SHS exposure at home/work/public locations based on sex. In common individual variables, such as age, and smoking status showed different relationships with SHS exposure in different locations. Among home-related variables, housing type and family with a single father and unmarried children showed the strongest positive relationships with SHS exposure in both males and females. In the workplace, service and sales workers, blue-collar workers, and manual laborers showed the strongest positive association with SHS exposure in males and females. For multilevel analysis in public places, only SHS exposure in females was positively related with cancer screening rate. Exposure to SHS in public places showed a positive relationship with drinking rate and single-parent family in males and females. The problem of SHS embodies social policies and interactions between individuals and social contextual factors. Policy makers should consider the contextual factors of specific locations and regional and individual context, along with differences between males and females, to develop effective strategies for reducing SHS exposure.

Experimental Study of Na based Titanium Nanofluid-Water Reaction

Energy Technology Data Exchange (ETDEWEB)

Park, Gunyeop; Kim, Soo Jae; Baek, Jehyun; Kim, Hyun Soo; Oh, Sun Ryung; Park, Hyun Sun; Kim, Moo Hwan [POSTECH, Pohang (Korea, Republic of)

2015-10-15

In KALIMER-600, a sodium-cooled fast reactor designed by KAERI, thermal energy is transported from high-temperature liquid Na (526 .deg. C at 0.1 MPa) to low temperature water (230 .deg. C at - 19.5 MPa) through a heat exchanger. If any leakage or rupture occurs during the operation of this heat exchanger, highly pressurized liquid water can penetrate into the liquid Na channels; this contact should instantly cause SWR. As reaction continues, liquid water is soon vaporized by pressure drop and huge amount of reaction heat. This generated water vapor expands large reaction area and increases sodium-water vapor reaction process. Therefore, the rapid generation of reaction product (like H{sub 2}) and water vapor increases the system pressure that can cause the system failure in SFR. To reduce this strong chemical reaction phenomena between Na and water, some we have focused on suppressing the chemical reactivity of liquid Na by dispersing nanoparticles (NPs). For the real application of NaTiNF, the pressure change induced by NaTiNF-water reaction is compared with Na-water reaction in the present study. NaTiNF contains 100nm of Ti NPs at 0.2 vol. %. The reaction rate of NaTiNF-water reaction is also investigated as reaction temperature increases. Sodium-water vapor reaction (SVR) will occur when an SWR accident occurs in SFR. In this manner, NaTiNF-water vapor reaction is experimentally performed for ensuring the suppression of chemical reactivity of NaTiNF in contact with water vapor. In the basic step for reducing risk of an SWR in SFR, we have experimentally verified the suppressed chemical reactivity of liquid sodium using Ti NPs through SWR and SVR experiments. In SWR, Na based titanium nanofluid (NaTiNF) shows lower pressure change than Na. As T{sub R} increases, P{sub max} in Na-water reaction increases while NaTiNF does not. The reaction rate of NaTiNF shows twice slower than that of Na. In SVR, NaTiNF shows slower temperature increase than Na. The distinct

A review of community-based solar home system projects in the Philippines

Directory of Open Access Journals (Sweden)

Macabebe Erees Queen B.

2016-01-01

Full Text Available Solar Home Systems (SHS are easy to deploy in island and in remote communities where grid connection is costly. However, issues related to maintenance of these systems emerge after they are deployed because of the remoteness and inaccessibility of the communities. This study looked into community-based programs in the Philippines and investigated the following: (1 social preparation, (2 role of the community in the project, and (3 sustainability of the program. In this paper, three communities under two government programs offering SHS are presented. These programs are the Solar Power Technology Support (SPOTS program of the Department of Agrarian Reform (DAR and the Household Electrification Program (HEP of the Department of Energy (DOE. A focused group discussion and key informant interviews were conducted in two communities in Bukidnon province and in a community in Kalinga to obtain information from the project beneficiaries and SHS users on the preparation, implementation and maintenance of the projects. The results revealed that emphasis on the economic value of the technology, proper training of the locals on the technical and management aspects of the project, as well as the establishment of a supply chain for replacement parts are crucial factors for the sustainability of the programs.

Maillard reaction in mild-based foods: nutritional consequences.

Science.gov (United States)

Pizzoferrato, L; Manzi, P; Vivanti, V; Nicoletti, I; Corradini, C; Cogliandro, E

1998-02-01

Chemical reactions occurring during industrial treatments or storage foods can lead to the formation of epsilon-deoxyketosyl compounds, the Amadori products. Food protein value can be adversely affected by these reactions, and in particular lysine, an essential amino acid having on its side chain a free amino group, can be converted to nonbioavailable N-substituted lysine or blocked lysine. by acid hydrolysis of epsilon-deoxyketosyl compounds, furosine is formed. In this paper furosine prepared from milk-based commercial products has been evaluated by use of a recently developed HPLC method using a microbore column and phosphate buffer as the mobile phase at controlled temperature. Furosine levels have been used, together with protein, total amino acids, and lysine content, as an estimate of protein quality of a few different products such as cooked-cream dessert, yogurt mousse, white chocolate, milk chocolate, milk chocolate with a soft nougat and caramel center, milk chocolate with a whipped white center, chocolate spread, part-skim milk tablets, milk-based dietetic meals, and baby foods. The protein content of the analyzed products ranged from 34.3 gxkg(-1) (milk nougat) to 188.4 g x kg(-1) (milk tablets). The Maillard reaction caused a loss in available lysine that varied from 2.5% (cooked cream) to 36.2% (condensed milk). The contribution to the lysine average daily requirement is heavily affected by this reaction and varied from 13% (milk tablets and soft nougat) to 61% (dietetic meal). Variable results were also obtained for the other essential amino acids.

Cardiovascular Consequences of Childhood Secondhand Tobacco Smoke Exposure: Prevailing Evidence, Burden, and Racial and Socioeconomic Disparities: A Scientific Statement From the American Heart Association.

Science.gov (United States)

Raghuveer, Geetha; White, David A; Hayman, Laura L; Woo, Jessica G; Villafane, Juan; Celermajer, David; Ward, Kenneth D; de Ferranti, Sarah D; Zachariah, Justin

2016-10-18

Although public health programs have led to a substantial decrease in the prevalence of tobacco smoking, the adverse health effects of tobacco smoke exposure are by no means a thing of the past. In the United States, 4 of 10 school-aged children and 1 of 3 adolescents are involuntarily exposed to secondhand tobacco smoke (SHS), with children of minority ethnic backgrounds and those living in low-socioeconomic-status households being disproportionately affected (68% and 43%, respectively). Children are particularly vulnerable, with little control over home and social environment, and lack the understanding, agency, and ability to avoid SHS exposure on their own volition; they also have physiological or behavioral characteristics that render them especially susceptible to effects of SHS. Side-stream smoke (the smoke emanating from the burning end of the cigarette), a major component of SHS, contains a higher concentration of some toxins than mainstream smoke (inhaled by the smoker directly), making SHS potentially as dangerous as or even more dangerous than direct smoking. Compelling animal and human evidence shows that SHS exposure during childhood is detrimental to arterial function and structure, resulting in premature atherosclerosis and its cardiovascular consequences. Childhood SHS exposure is also related to impaired cardiac autonomic function and changes in heart rate variability. In addition, childhood SHS exposure is associated with clustering of cardiometabolic risk factors such as obesity, dyslipidemia, and insulin resistance. Individualized interventions to reduce childhood exposure to SHS are shown to be at least modestly effective, as are broader-based policy initiatives such as community smoking bans and increased taxation. The purpose of this statement is to summarize the available evidence on the cardiovascular health consequences of childhood SHS exposure; this will support ongoing efforts to further reduce and eliminate SHS exposure in this

Synthesis of titanium carbide from wood by self-propagating high temperature synthesis

Directory of Open Access Journals (Sweden)

Sutham Niyomwas

2010-05-01

Full Text Available Titanium carbide (TiC particles were obtained in situ by a self-propagating high temperature synthesis (SHS of wooddust with TiO2 and Mg. The reaction was carried out in a SHS reactor under static argon gas at the pressure of 0.5 MPa. Thestandard Gibbs energy minimization method was used to calculate the equilibrium composition of the reacting species. Theeffects of increasing Mg mole ratio to the precursor mixture of TiO2 and wood dusts were investigated. XRD and SEManalyses indicate a complete reaction of the precursors to yield TiC-MgO as a product composite. The synthesized compositeswere leached with 0.1M HCl acid solution to obtain TiC particles as final products.

Stoichiometric Representation of Gene–Protein–Reaction Associations Leverages Constraint-Based Analysis from Reaction to Gene-Level Phenotype Prediction

DEFF Research Database (Denmark)

Machado, Daniel; Herrgard, Markus; Rocha, Isabel

2016-01-01

only describe the metabolic phenotype at the reaction level, understanding the mechanistic link between genotype and phenotype is still hampered by the complexity of gene-protein-reaction associations. We implement a model transformation that enables constraint-based methods to be applied at the gene...... design methods are not actually feasible, and show how our approach allows using the same methods to obtain feasible gene-based designs. We also show, by extensive comparison with experimental 13C-flux data, how simple reformulations of different simulation methods with gene-wise objective functions...

Metabonomics-Based Study of Clinical Urine Samples in Suboptimal Health with Different Syndromes

Directory of Open Access Journals (Sweden)

Hai-Zhen Cui

2013-01-01

Full Text Available Objective. To explore the urinary biochemistry features of syndromes of traditional Chinese medicine (TCM such as syndrome of stagnation of liver Qi, spleen deficiency, liver Qi stagnation, and spleen deficiency (LSSDS in sub-optimal health status (SHS. Methods. 12 cases for each syndrome group in SHS were selected, 12 subjects were used as a normal control group, and 1H NMR detection was, respectively, carried out, and the data was corrected by the orthogonal signal correction (OSC and then adopted a partial least squares (PLS method for discriminate analysis. Results. The OSC-PLS (ctr analysis results of the nuclear overhauser enhancement spectroscopy (NOESY detection indicated that the syndromes in SHS could be differentiated, and there were significant differences in the levels of metabolites of the urine samples of the four groups; the biomarkers of LSSDS in SHS were found out. The contents of citric acid (2.54 and 2.66, trimethylamineoxide (3.26, and hippuric acid (3.98, 7.54, 7.58, 7.62, 7.66, 7.82, and 7.86 in the urine samples of LSSDS group were lower than that of the normal control group. Conclusion. There are differences in the 1H-NMR metabolic spectrum of the urine samples of the four groups, and the specific metabolic products of the LSSDS in SHS can be identified from metabonomics analysis.

Parallel proton transfer pathways in aqueous acid-base reactions

NARCIS (Netherlands)

Cox, M.J.; Bakker, H.J.

2008-01-01

We study the mechanism of proton transfer (PT) between the photoacid 8-hydroxy-1,3, 6-pyrenetrisulfonic acid (HPTS) and the base chloroacetate in aqueous solution. We investigate both proton and deuteron transfer reactions in solutions with base concentrations ranging from 0.25M to 4M. Using

Investigation of the physical and numerical foundations of two-fluid representation of sodium boiling with applications to LMFBR experiments

International Nuclear Information System (INIS)

No, H.C.; Kazimi, M.S.

1983-03-01

This work involves the development of physical models for the constitutive relations of a two-fluid, three-dimensional sodium boiling code, THERMIT-6S. The code is equipped with a fluid conduction model, a fuel pin model, and a subassembly wall model suitable for stimulating LMFBR transient events. Mathematically rigorous derivations of time-volume averaged conservation equations are used to establish the differential equations of THERMIT-6S. These equations are then discretized in a manner identical to the original THERMIT code. A virtual mass term is incorporated in THERMIT-6S to solve the ill-posed problem. Based on a simplified flow regime, namely cocurrent annular flow, constitutive relations for two-phase flow of sodium are derived. The wall heat transfer coefficient is based on momentum-heat transfer analogy and a logarithmic law for liquid film velocity distribution. A broad literature review is given for two-phase friction factors. It is concluded that entrainment can account for some of the discrepancies in the literature. Mass and energy exchanges are modelled by generalization of the turbulent flux concept. Interfacial drag coefficients are derived for annular flows with entrainment. Code assessment is performed by simulating three experiments for low flow-high power accidents and one experiment for low flow/low power accidents in the LMFBR. While the numerical results for pre-dryout are in good agreement with the data, those for post-dryout reveal the need for improvement of the physical models. The benefits of two-dimensional non-equilibrium representation of sodium boiling are studied

Factors associated with secondhand smoke exposure in different settings: Results from the German Health Update (GEDA) 2012.

Science.gov (United States)

Fischer, Florian; Kraemer, Alexander

2016-04-14

The ubiquity of secondhand smoke (SHS) exposure at home or in private establishments, workplaces and public areas poses several challenges for the reduction of SHS exposure. This study aimed to describe the prevalence of SHS exposure in Germany and key factors associated with exposure. Results were also differentiated by place of exposure. A secondary data analysis based on the public use file of the German Health Update 2012 was conducted (n = 13,933). Only non-smokers were included in the analysis. In a multivariable logistic regression model the factors associated with SHS exposure were calculated. In addition, a further set of multivariable logistic regressions were calculated for factors associated with the place of SHS exposure (workplace, at home, bars/discotheques, restaurants, at the house of a friend). More than a quarter of non-smoking study participants were exposed to SHS. The main area of exposure was the workplace (40.9 %). The multivariable logistic regression indicated young age as the most important factor associated with SHS exposure. The odds for SHS exposure was higher in men than in women. The likelihood of SHS exposure decreased with higher education. SHS exposure and the associated factors varied between different places of exposure. Despite several actions to protect non-smokers which were implemented in Germany during the past years, SHS exposure still remains a relevant risk factor at a population level. According to the results of this study, particularly the workplace and other public places such as bars and discotheques have to be taken into account for the development of strategies to reduce SHS exposure.

Characterization of Ignition and Combustion Properties of Nanowire-based Energetics

Science.gov (United States)

2013-07-23

cantly improves the overall spatial uniformity of the nano-thermites, and provides an ideal platform for the study of the thermodynamic and kinetic...problem in solids. In addition, heat provided by the Xe lamp is mainly absorbed by the porous Si according to the Beer -Lambert Law, not by the glass slide

Electro-catalytic activity of Ni–Co-based catalysts for oxygen evolution reaction

Energy Technology Data Exchange (ETDEWEB)

Ju, Hua [School of Urban Rail Transportation, Soochow University, Suzhou 215006 (China); Li, Zhihu [College of Physics, Optoelectronics and Energy, Soochow University, Moye Rd. 688, Suzhou 215006 (China); Xu, Yanhui, E-mail: xuyanhui@suda.edu.cn [College of Physics, Optoelectronics and Energy, Soochow University, Moye Rd. 688, Suzhou 215006 (China)

2015-04-15

Graphical abstract: The electro-catalytic activity of different electro-catalysts with a porous electrode structure was compared considering the real electrode area that was evaluated by cyclic measurement. - Highlights: • Ni–Co-based electro-catalysts for OER have been studied and compared. • The real electrode area is calculated and used for assessing the electro-catalysts. • Exchange current and reaction rate constant are estimated. • Ni is more useful for OER reaction than Co. - Abstract: In the present work, Ni–Co-based electrocatalysts (Ni/Co = 0:6, 1:5, 2:4, 3:3, 4:2, 5:1 and 6:0) have been studied for oxygen evolution reaction. The phase structure has been analyzed by X-ray diffraction technique. Based on the XRD and SEM results, it is believed that the synthesized products are poorly crystallized. To exclude the disturbance of electrode preparation technology on the evaluation of electro-catalytic activity, the real electrode surface area is calculated based on the cyclic voltammetry data, assumed that the specific surface capacitance is 60 μF cm{sup −2} for metal oxide electrode. The real electrode area data are used to calculate the current density. The reaction rate constant of OER at different electrodes is also estimated based on basic reaction kinetic equations. It is found that the exchange current is 0.05–0.47 mA cm{sup −2} (the real surface area), and the reaction rate constant has an order of magnitude of 10{sup −7}–10{sup −6} cm s{sup −1}. The influence of the electrode potential on OER rate has been also studied by electrochemical impedance spectroscopy (EIS) technique. Our investigation has shown that the nickel element has more contribution than the cobalt; the nickel oxide has the best electro-catalytic activity toward OER.

Sex and Age Differences in Exposure to Secondhand Smoke at Home among Korean Adolescents: A Nationally Representative Survey.

Science.gov (United States)

Hwang, Jun Hyun; Park, Soon-Woo

2016-02-19

The authors assessed sex and age differences in secondhand smoke (SHS) exposure among vulnerable adolescent populations. Data from the 2013 Korea Youth Risk Behavior Web-based Survey of 64,499 non-smokers aged 13-18 years were analyzed using multiple logistic regression. Girls were exposed 1.26 times (95% confidence interval, 1.21-1.32) more to home SHS than boys, and the younger adolescents were more likely to be exposed to home SHS than were the older, regardless of sex (p exposure at home. Girls living with current smokers were more likely to be exposed to SHS at home than boys regardless age. Girls and younger adolescents, populations vulnerable to smoke exposure, were more likely to be exposed to SHS at home, even though they should be more protected. It is necessary to improve home SHS awareness, especially among these vulnerable populations.

Interfacial mechanisms of heterogeneous Fenton reactions catalyzed by iron-based materials: A review.

Science.gov (United States)

He, Jie; Yang, Xiaofang; Men, Bin; Wang, Dongsheng

2016-01-01

The heterogeneous Fenton reaction can generate highly reactive hydroxyl radicals (OH) from reactions between recyclable solid catalysts and H2O2 at acidic or even circumneutral pH. Hence, it can effectively oxidize refractory organics in water or soils and has become a promising environmentally friendly treatment technology. Due to the complex reaction system, the mechanism behind heterogeneous Fenton reactions remains unresolved but fascinating, and is crucial for understanding Fenton chemistry and the development and application of efficient heterogeneous Fenton technologies. Iron-based materials usually possess high catalytic activity, low cost, negligible toxicity and easy recovery, and are a superior type of heterogeneous Fenton catalysts. Therefore, this article reviews the fundamental but important interfacial mechanisms of heterogeneous Fenton reactions catalyzed by iron-based materials. OH, hydroperoxyl radicals/superoxide anions (HO2/O2(-)) and high-valent iron are the three main types of reactive oxygen species (ROS), with different oxidation reactivity and selectivity. Based on the mechanisms of ROS generation, the interfacial mechanisms of heterogeneous Fenton systems can be classified as the homogeneous Fenton mechanism induced by surface-leached iron, the heterogeneous catalysis mechanism, and the heterogeneous reaction-induced homogeneous mechanism. Different heterogeneous Fenton systems catalyzed by characteristic iron-based materials are comprehensively reviewed. Finally, related future research directions are also suggested. Copyright © 2015. Published by Elsevier B.V.

Proton exchange in acid–base complexes induced by reaction coordinates with heavy atom motions

International Nuclear Information System (INIS)

Alavi, Saman; Taghikhani, Mahdi

2012-01-01

Highlights: ► Proton exchange in acid–base complexes is studied. ► The structures, binding energies, and normal mode vibrations are calculated. ► Transition state structures of proton exchange mechanism are determined. ► In the complexes studied, the reaction coordinate involves heavy atom rocking. ► The reaction coordinate is not simply localized in the proton movements. - Abstract: We extend previous work on nitric acid–ammonia and nitric acid–alkylamine complexes to illustrate that proton exchange reaction coordinates involve the rocking motion of the base moiety in many double hydrogen-bonded gas phase strong acid–strong base complexes. The complexes studied involve the biologically and atmospherically relevant glycine, formic, acetic, propionic, and sulfuric acids with ammonia/alkylamine bases. In these complexes, the magnitude of the imaginary frequencies associated with the proton exchange transition states are −1 . This contrasts with widely studied proton exchange reactions between symmetric carboxylic acid dimers or asymmetric DNA base pair and their analogs where the reaction coordinate is localized in proton motions and the magnitude of the imaginary frequencies for the transition states are >1100 cm −1 . Calculations on complexes of these acids with water are performed for comparison. Variations of normal vibration modes along the reaction coordinate in the complexes are described.

Mejora en la producción de recubrimientos de NiAl obtenidos por síntesis autopropagada a alta temperatura mediante energía solar concentrada

Directory of Open Access Journals (Sweden)

Sierra, C.

2005-12-01

Full Text Available The production of NiAl coatings on steel can be achieved in a quick, cheap and unpolluted way. All this advantages are possible using concentrated solar energy (CSE and selfpropagating high-temperature synthesis (SHS. SHS process allows the production of NiAl in short periods of using of the heat released in the reaction. Initial energy is provided by concentrated solar energy. The aim of this work is to improve the adherence between steel and coating. Two kinds of samples are examined: samples with Ni powder layer, and samples electroplated with nickel.

Se presenta un procedimiento para la obtención de recubrimientos de NiAl sobre acero, de forma rápida, barata y limpia desde el punto de vista medioambiental. Todas estas ventajas son posibles mediante el empleo combinado de la Energía Solar Concentrada (CSE y la Síntesis Autopropagada a Alta Temperatura (SHS aplicada a la producción de intermetálicos. Las reacciones SHS permiten la obtención de NiAl en procesos de corta duración, prácticamente instantáneos, aprovechando la elevada exotermicidad de la propia reacción. El aporte energético inicial se realiza concentrando radiación solar con una lente de Fresnel. El objetivo del trabajo presentado era mejorar la adherencia del recubrimiento de NiAl al acero base; se comparan los resultados de los ensayos entre probetas con una capa intermedia de polvo de níquel y probetas con níquel electrodepositado.

Quality issues in the market based dissemination of solar home systems

Energy Technology Data Exchange (ETDEWEB)

Lindner, Klara [MicroEnergy International, Berlin (Germany)

2011-07-01

In general, Photovoltaic systems are built to last and require little maintenance. However, field studies have revealed a high number of system failures, which are linked to a lack of quality assurance. This paper depicts problems that occur with solar home systems (SHS) disseminated on a market-based approach. The research methodology is based on three pillars: A literature review covers documented projects around the world dealing with solar home system dissemination. Expert practitioners drawn together in a workshop have shared valuable experiences, while a trip to rural Tanzania has been carried out to collect personal insights from the field. To facilitate continuous sharing of challenges between different stakeholders, common quality issues are grouped into four categories according to their cause: component quality, system integration, business model and framework conditions. While the solar component and the user are often initially blamed for system failure, it shows that difficulties arise at various levels of the SHS life cycle - this paper highlights focus problems within each stage. As a root, three underlying challenges are suggested: maladjusted systems, inadequate installations and a disorganized after-sales service. A possible instrument to assure better quality in this context is the enforcement of standards also in market-based SHS sales. Microfinance institutions are assumed as an important partner, because only clients with a functioning system are willing to repay the linked loan. As most of these institutions lack technical knowledge, they can only become an agent for their clients' wish for customer protection, if an independent facility certifies the system's functionality. The given recommendation is that a sustainable approach for solar home system dissemination should not attempt to increase the affordability by developing cheaper products but by fostering income-generating activities, which facilitate paying for good quality

Sex and Age Differences in Exposure to Secondhand Smoke at Home among Korean Adolescents: A Nationally Representative Survey

Directory of Open Access Journals (Sweden)

Jun Hyun Hwang

2016-02-01

Full Text Available The authors assessed sex and age differences in secondhand smoke (SHS exposure among vulnerable adolescent populations. Data from the 2013 Korea Youth Risk Behavior Web-based Survey of 64,499 non-smokers aged 13–18 years were analyzed using multiple logistic regression. Girls were exposed 1.26 times (95% confidence interval, 1.21–1.32 more to home SHS than boys, and the younger adolescents were more likely to be exposed to home SHS than were the older, regardless of sex (p < 0.001. Younger girls living with or without current smokers and the younger boys living with current smokers were more likely to be exposed to SHS at home, when the data were stratified according to current household member smoking, which was one of the main risk factors for SHS exposure at home. Girls living with current smokers were more likely to be exposed to SHS at home than boys regardless age. Girls and younger adolescents, populations vulnerable to smoke exposure, were more likely to be exposed to SHS at home, even though they should be more protected. It is necessary to improve home SHS awareness, especially among these vulnerable populations.

Research progress on trifluoromethyl-based radical reaction process

Science.gov (United States)

Song, Hao

2017-12-01

Due to the unique properties imparted by the trifluoromethyl group, such as high electron density and strong lipotropy, which effectively improve acidity, lipophilicity and metabolic stability of the molecule itself, trifluoromethyl-substituted organic compounds are becoming increasingly important as structural motifs in pharmaceuticals, agrochemicals and organic materials. In this review, we present several methods developed for the direct introduction of a trifluoromethyl group, beginning with its rich and storied history. Then the present article addresses mechanism and process in carbon-carbon bond forming reaction based on radical process which is divided into three parts according to the way of CF3 radical generation. Finally, challenges and opportunities of researches on trifluoromethylation reactions facing are prospected.

New era of silicon technologies due to radical reaction based semiconductor manufacturing

International Nuclear Information System (INIS)

Ohmi, Tadahiro; Hirayama, Masaki; Teramoto, Akinobu

2006-01-01

Current semiconductor technology, the so-called the molecule reaction based semiconductor manufacturing, now faces a very severe standstill due to the drastic increase of gate leakage currents and drain leakage currents. Radical reaction based semiconductor manufacturing has been developed to completely overcome the current standstill by introducing microwave excited high density plasma with very low electron temperatures and without accompanying charge-up damage. The introduction of radical reaction based semiconductor manufacturing has made it possible to fabricate LSI devices on any crystal orientation Si substrate surface as well as (100) Si substrate surfaces, and to eliminate a very severe limitation to the antenna ratio in the circuit layout patterns, which is strictly limited to less than 100-200 in order to obtain a relatively high production yield. (topical review)

A case report on a severe anaphylaxis reaction to Gadolinium-based MR contrast media

Energy Technology Data Exchange (ETDEWEB)

Park, Juil; Kim, Tae Hyung; Park, Chang Min; Yoon, Soon Ho; Lee, Whal; Kang, Hye Ryun; Choi, Young Hun [Seoul National University Hospital, Seoul (Korea, Republic of)

2017-02-15

Acute hypersensitivity reactions to gadolinium-based magnetic resonance (MR) contrast media have been shown to have a much lower incidence and they are generally milder in terms of severity than acute adverse reactions associated with the use of iodinated contrast media for computed tomography scans. However, even though it is rare, a severe hypersensitivity reaction to MR contrast media can occur. Here we present the case of a 66-year-old woman who experienced a severe hypersensitivity reaction after administration of gadolinium-based contrast media without a previous history of allergies.

Efficient rejection-based simulation of biochemical reactions with stochastic noise and delays

Energy Technology Data Exchange (ETDEWEB)

Thanh, Vo Hong, E-mail: vo@cosbi.eu [The Microsoft Research - University of Trento Centre for Computational and Systems Biology, Piazza Manifattura 1, Rovereto 38068 (Italy); Priami, Corrado, E-mail: priami@cosbi.eu [The Microsoft Research - University of Trento Centre for Computational and Systems Biology, Piazza Manifattura 1, Rovereto 38068 (Italy); Department of Mathematics, University of Trento (Italy); Zunino, Roberto, E-mail: roberto.zunino@unitn.it [Department of Mathematics, University of Trento (Italy)

2014-10-07

We propose a new exact stochastic rejection-based simulation algorithm for biochemical reactions and extend it to systems with delays. Our algorithm accelerates the simulation by pre-computing reaction propensity bounds to select the next reaction to perform. Exploiting such bounds, we are able to avoid recomputing propensities every time a (delayed) reaction is initiated or finished, as is typically necessary in standard approaches. Propensity updates in our approach are still performed, but only infrequently and limited for a small number of reactions, saving computation time and without sacrificing exactness. We evaluate the performance improvement of our algorithm by experimenting with concrete biological models.

Generic Model-Based Tailor-Made Design and Analysis of Biphasic Reaction Systems

DEFF Research Database (Denmark)

Anantpinijwatna, Amata

systems have a broad range of application, such as the manufacture of petroleum based chemicals, pharmaceuticals, and agro-bio products. Major considerations in the design and analysis of biphasic reaction systems are physical and chemical equilibria, kinetic mechanisms, and reaction rates. The primary...... contribution of this thesis is the development of a systematic modelling framework for the biphasic reaction system. The developed framework consists of three modules describing phase equilibria, reactions and mass transfer, and material balances of such processes. Correlative and predictive thermodynamic......Biphasic reaction systems are composed of immiscible aqueous and organic liquid phases where reactants, products, and catalysts are partitioned. These biphasic conditions point to novel synthesis paths, higher yields, and faster reactions, as well as facilitate product separation. The biphasic...

Stable and efficient nitrogen-containing-carbon based electrocatalysts for reactions in energy conversion systems.

Science.gov (United States)

Wang, Sicong; Teng, Zhenyuan; Wang, Chengyin; Wang, Guoxiu

2018-05-17

High activity and stability are crucial for practical electrocatalysts used for reactions in fuel cells, metal-air batteries and water electrolysis including ORR, HER, OER and oxidation reactions of formic acid and alcohols. N-C based electrocatalysts have shown promising prospects for catalyzing these reactions, however, there is no systematic review for strategies toward engineering active and stable N-C based electrocatalysts reported by far. Herein, a comprehensive comparison of recently reported N-C based electrocatalysts regarding both electrocatalytic activity and long-term stability is presented. In the first part of this review, relationships between electrocatalytic reactions and element selections for modifying N-C based materials are discussed. Afterwards, synthesis methods for N-C based electrocatalysts are summarized, and synthetic strategies for highly stable N-C based electrocatalysts are presented. Multiple tables containing data on crucial parameters for both electrocatalytic activity and stability are displayed in this review. Finally, constructing M-Nx moieties is proposed as the most promising engineering strategy for stable N-C based electrocatalysts. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Parental smoking, exposure to secondhand smoke at home, and smoking initiation among young children.

Science.gov (United States)

Wang, Man Ping; Ho, Sai Yin; Lam, Tai Hing

2011-09-01

To investigate the associations of parental smoking and secondhand smoke (SHS) exposure at home with smoking initiation among young children in Hong Kong. A prospective school-based survey of Hong Kong primary 2-4 students was conducted at baseline in 2006 and followed up in 2008. Self-administered anonymous questionnaires were used to collect information about smoking, SHS exposure at home, parental smoking, and sociodemographic characteristics. Cross-sectional and prospective associations of SHS exposure at home and parental smoking with student smoking were analyzed using logistic regression adjusting for potential confounders. Cross-sectional association between parental smoking and ever smoking was significant with adjustment of sociodemographic characteristics but became insignificant after adjusting for home SHS exposure. Home SHS exposure mediated the association between parental smoking and students smoking (p = .03). Prospectively, parental smoking was not associated with smoking initiation after adjusting for home SHS exposure. Each day increase in home SHS exposure significantly predicted 16% excess risk of smoking initiation after adjusting for parental smoking. The prospective effect of parental smoking on smoking initiation was significantly mediated by baseline home SHS exposure (p smoking initiation of young Chinese children in Hong Kong independent of parental smoking status. On the other hand, the effect of parental smoking on smoking initiation was mediated through SHS exposure at home. To prevent children from smoking as well as the harm of SHS exposure, parents and other family members should quit smoking or at least reduce smoking at home.

Associations between breakfast eating habits and health-promoting lifestyle, suboptimal health status in Southern China: a population based, cross sectional study.

Science.gov (United States)

Chen, Jieyu; Cheng, Jingru; Liu, Yanyan; Tang, Yang; Sun, Xiaomin; Wang, Tian; Xiao, Ya; Li, Fei; Xiang, Lei; Jiang, Pingping; Wu, Shengwei; Wu, Liuguo; Luo, Ren; Zhao, Xiaoshan

2014-12-11

Suboptimal health status (SHS) is the intermediate health state between health and disease, refers to medically undiagnosed or functional somatic syndromes, and has been a major global public health challenge. However, both the etiology and mechanisms associated with SHS are still unclear. Breakfast eating behavior is a dietary pattern marker and previous studies have presented evidence of associations between failure to consume breakfast and increased diseases. Accordingly, in view of the significance of breakfast eating behaviors with respect to health status, the associations between breakfast eating habits and healthy lifestyle, SHS require further elucidation. A cross-sectional survey was conducted within a clustered sample of 24,159 individuals aged 12-80 years in 2012-13 within the population of Southern China. Breakfast eating habits were categorically defined by consumption frequency ('scarcely, sometimes or always'). Health-promoting lifestyle was assessed via the health-promoting lifestyle profile (HPLP-II). SHS was evaluated using the medical examination report and Sub-health Measurement Scale V1.0 (SHMS V1.0). Of the 24,159 participants, the prevalence rates for the 'health' , 'SHS' , and 'disease' were 18.8%, 46.0%, and 35.2%, respectively. Overall, 19.6% of participants reported 'scarce' breakfast eating habits, with frequent breakfast eaters scoring higher on both HPLP-II and SHMS V1.0. After demographic adjustment, regression analyses revealed a significant association between breakfast eating habits and healthy lifestyle (p eating habits are significantly associated with a healthy lifestyle, and appear to be a useful predictor of a healthy lifestyle. Irregular breakfast eating habits are related to an increased risk of SHS; increased breakfast eating frequency may contribute to lowering the prevalence of SHS in Southern China.

Laser Spot Detection Based on Reaction Diffusion.

Science.gov (United States)

Vázquez-Otero, Alejandro; Khikhlukha, Danila; Solano-Altamirano, J M; Dormido, Raquel; Duro, Natividad

2016-03-01

Center-location of a laser spot is a problem of interest when the laser is used for processing and performing measurements. Measurement quality depends on correctly determining the location of the laser spot. Hence, improving and proposing algorithms for the correct location of the spots are fundamental issues in laser-based measurements. In this paper we introduce a Reaction Diffusion (RD) system as the main computational framework for robustly finding laser spot centers. The method presented is compared with a conventional approach for locating laser spots, and the experimental results indicate that RD-based computation generates reliable and precise solutions. These results confirm the flexibility of the new computational paradigm based on RD systems for addressing problems that can be reduced to a set of geometric operations.

Disparity and Trends in Secondhand Smoke Exposure among Japanese Employees, Particularly Smokers vs. Non-Smokers.

Science.gov (United States)

Tabuchi, Takahiro; Colwell, Brian

2016-01-01

Monitoring disparities in secondhand smoke (SHS) exposure is important for tailoring smoke-free policies to the needs of different groups. We examined disparity and trends in SHS exposure among both nonsmokers and smokers at Japanese workplaces between 2002 and 2012. A total of 32,940 employees in nationally representative, population-based, repeated cross-sectional surveys in 2002, 2007 and 2012 in Japan was analyzed. Adjusted rate ratios for workplace SHS exposure from other people ("everyday" and "everyday or sometimes") were calculated according to covariates, using log-binomial regression models with survey weights. In this survey, employees who do not smoke at workplace are defined as workplace-nonsmokers; and those smoke at workplace are used as workplace-smokers. SHS exposure for smokers does not involve their own SHS. While everyday SHS exposure prevalence in workplace-nonsmokers decreased markedly (33.2% to 11.4%), that in workplace-smokers decreased only slightly (63.3% to 55.6%). Workplace-smokers were significantly more likely to report everyday SHS exposure than workplace-nonsmokers, and the degree of association increased over time: compared with the nonsmokers (reference), covariates-adjusted rate ratio (95% confidence interval) for the smokers increased from 1.70 (1.62-1.77) in 2002 to 4.16 (3.79-4.56) in 2012. Similar results were observed for everyday or sometimes SHS exposure. Compared with complete workplace smoking bans, partial and no bans were consistently and significantly associated with high SHS exposure among both nonsmokers and smokers. We also observed disparities in SHS exposure by employee characteristics, such as age group and worksite scale. Although overall SHS exposure decreased among Japanese employees between 2002 and 2012, the SHS exposure disparity between nonsmokers and smokers widened. Because smokers reported more frequent SHS exposure than nonsmokers, subsequent mortality due to SHS exposure may be higher in smokers than

Interfacial Redox Reactions Associated Ionic Transport in Oxide-Based Memories.

Science.gov (United States)

Younis, Adnan; Chu, Dewei; Shah, Abdul Hadi; Du, Haiwei; Li, Sean

2017-01-18

As an alternative to transistor-based flash memories, redox reactions mediated resistive switches are considered as the most promising next-generation nonvolatile memories that combine the advantages of a simple metal/solid electrolyte (insulator)/metal structure, high scalability, low power consumption, and fast processing. For cation-based memories, the unavailability of in-built mobile cations in many solid electrolytes/insulators (e.g., Ta 2 O 5 , SiO 2 , etc.) instigates the essential role of absorbed water in films to keep electroneutrality for redox reactions at counter electrodes. Herein, we demonstrate electrochemical characteristics (oxidation/reduction reactions) of active electrodes (Ag and Cu) at the electrode/electrolyte interface and their subsequent ions transportation in Fe 3 O 4 film by means of cyclic voltammetry measurements. By posing positive potentials on Ag/Cu active electrodes, Ag preferentially oxidized to Ag + , while Cu prefers to oxidize into Cu 2+ first, followed by Cu/Cu + oxidation. By sweeping the reverse potential, the oxidized ions can be subsequently reduced at the counter electrode. The results presented here provide a detailed understanding of the resistive switching phenomenon in Fe 3 O 4 -based memory cells. The results were further discussed on the basis of electrochemically assisted cations diffusions in the presence of absorbed surface water molecules in the film.

Fatal anaphylactic reaction to intravenous gadobutrol, a gadolinium-based MRI contrast agent

Directory of Open Access Journals (Sweden)

Sabine Franckenberg, MD

2018-02-01

Full Text Available We present the rare case of a fatal anaphylactic reaction to gadobutrol, a magnetic resonance imaging contrast agent, in a 42-year-old man. The patient underwent elective magnetic resonance imaging for diagnostic clarification of a suspicious finding in the abdomen. The patient had undergone contrast-enhanced computed tomography previously without the occurrence of any adverse effects. Adverse drug reactions in gadobutrol have a very low prevalence of 0.32%-3.5%, with serious adverse drug reactions in <0.1%. There are only a few cases of fatal anaphylactoid reactions to gadolinium-based contrast agents in general. However, if an anaphylactoid reaction occurs, it can present itself with a fulminant course within minutes.

Nuclear reactions video (knowledge base on low energy nuclear physics)

International Nuclear Information System (INIS)

Zagrebaev, V.; Kozhin, A.

1999-01-01

The NRV (nuclear reactions video) is an open and permanently extended global system of management and graphical representation of nuclear data and video-graphic computer simulation of low energy nuclear dynamics. It consists of a complete and renewed nuclear database and well known theoretical models of low energy nuclear reactions altogether forming the 'low energy nuclear knowledge base'. The NRV solves two main problems: 1) fast and visualized obtaining and processing experimental data on nuclear structure and nuclear reactions; 2) possibility for any inexperienced user to analyze experimental data within reliable commonly used models of nuclear dynamics. The system is based on the realization of the following principal things: the net and code compatibility with the main existing nuclear databases; maximal simplicity in handling: extended menu, friendly graphical interface, hypertext description of the models, and so on; maximal visualization of input data, dynamics of studied processes and final results by means of real three-dimensional images, plots, tables and formulas and a three-dimensional animation. All the codes are composed as the real Windows applications and work under Windows 95/NT

Does shoe heel design influence ground reaction forces and knee moments during maximum lunges in elite and intermediate badminton players?

Science.gov (United States)

Lam, Wing-Kai; Ryue, Jaejin; Lee, Ki-Kwang; Park, Sang-Kyoon; Cheung, Jason Tak-Man; Ryu, Jiseon

2017-01-01

Lunge is one frequently executed movement in badminton and involves a unique sagittal footstrike angle of more than 40 degrees at initial ground contact compared with other manoeuvres. This study examined if the shoe heel curvature design of a badminton shoe would influence shoe-ground kinematics, ground reaction forces, and knee moments during lunge. Eleven elite and fifteen intermediate players performed five left-forward maximum lunge trials with Rounded Heel Shoe (RHS), Flattened Heel Shoe (FHS), and Standard Heel Shoes (SHS). Shoe-ground kinematics, ground reaction forces, and knee moments were measured by using synchronized force platform and motion analysis system. A 2 (Group) x 3 (Shoe) ANOVA with repeated measures was performed to determine the effects of different shoes and different playing levels, as well as the interaction of two factors on all variables. Shoe effect indicated that players demonstrated lower maximum vertical loading rate in RHS than the other two shoes (P badminton lunge. The differences in impact loads and knee moments between elite and intermediate players may be useful in optimizing footwear design and training strategy to minimize the potential risks for impact related injuries in badminton.

High temperature synthesis of ceramic composition by directed reaction of molten titanium or zirconium with boron carbide

International Nuclear Information System (INIS)

Johnson, W.B.

1990-01-01

Alternative methods of producing ceramics and ceramic composites include sintering, hot pressing and more recently hot isostatic pressing (HIP) and self-propagating high temperature synthesis (SHS). Though each of these techniques has its advantages, each suffers from several restrictions as well. Sintering may require long times at high temperatures and for most materials requires sintering aids to get full density. These additives can, and generally do, change (often degrade) the properties of the ceramic. Hot pressing and hot isostatic pressing are convenient methods to quickly prepare samples of some materials to full density, but generally are expensive and may damage some types of reinforcements during densification. This paper focuses on the preparation and processing of composites prepared by the directed reaction of molten titanium or zirconium with boron carbide. Advantages and disadvantages of this approach when compared to traditional methods are discussed, with reference to specific examples. Examples of microstructure are properties of these materials are reported

Process for carrying out analyses based on concurrent reactions

Energy Technology Data Exchange (ETDEWEB)

Glover, J S; Shepherd, B P

1980-01-03

The invention refers to a process for carrying out analyses based on concurrent reactions. A part of a compound to be analysed is subjected with a standard quantity of this compound in a labelled form to a common reaction with a standard quantity of a reagent, which must be less than the sum of the two parts of the reacting compound. The parts of the marked reaction compound and the labelled final compound resulting from the concurrence are separated in a tube (e.g. by centrifuging) after forced phase change (precipitation, absorption etc.) and the radio-activity of both phases in contact is measured separately. The shielded measuring device developed for this and suitable for centrifuge tubes of known dimensions is also included in the patent claims. The insulin concentration of a defined serum is measured as an example of the applications of the method (Radioimmunoassay).

Directly measured secondhand smoke exposure and COPD health outcomes

Directory of Open Access Journals (Sweden)

Balmes John

2006-06-01

Full Text Available Abstract Background Although personal cigarette smoking is the most important cause and modulator of chronic obstructive pulmonary disease (COPD, secondhand smoke (SHS exposure could influence the course of the disease. Despite the importance of this question, the impact of SHS exposure on COPD health outcomes remains unknown. Methods We used data from two waves of a population-based multiwave U.S. cohort study of adults with COPD. 77 non-smoking respondents with a diagnosis of COPD completed direct SHS monitoring based on urine cotinine and a personal badge that measures nicotine. We evaluated the longitudinal impact of SHS exposure on validated measures of COPD severity, physical health status, quality of life (QOL, and dyspnea measured at one year follow-up. Results The highest level of SHS exposure, as measured by urine cotinine, was cross-sectionally associated with poorer COPD severity (mean score increment 4.7 pts; 95% CI 0.6 to 8.9 and dyspnea (1.0 pts; 95% CI 0.4 to 1.7 after controlling for covariates. In longitudinal analysis, the highest level of baseline cotinine was associated with worse COPD severity (4.7 points; 95% CI -0.1 to 9.4; p = 0.054, disease-specific QOL (2.9 pts; -0.16 to 5.9; p = 0.063, and dyspnea (0.9 pts; 95% CI 0.2 to 1.6 pts; p Conclusion Directly measured SHS exposure appears to adversely influence health outcomes in COPD, independent of personal smoking. Because SHS is a modifiable risk factor, clinicians should assess SHS exposure in their patients and counsel its avoidance. In public health terms, the effects of SHS exposure on this vulnerable subpopulation provide a further rationale for laws prohibiting public smoking.

Production of advanced materials by methods of self-propagating high-temperature synthesis

CERN Document Server

Tavadze, Giorgi F

2013-01-01

This translation from the original Russian book outlines the production of a variety of materials by methods of self-propagating high-temperature synthesis (SHS). The types of materials discussed include: hard, refractory, corrosion and wear-resistant materials, as well as other advanced and speciality materials. The authors address the issue of optimal parameters for SHS reactions occurring during processes involving a preliminary metallothermic reduction stage, and they calculate this using thermodynamic approaches. In order to confirm the effectiveness of this approach, the authors describe experiments focussing on the synthesis of elemental crysalline boron, boron carbides and nitrides. Other parts of this brief include theoretical and experimental results on single-stage production of hard alloys on the basis of titanium and zirconium borides, as well as macrokinetics of degassing and compaciton of SHS-products.This brief is suitable for academics, as well as those working in industrial manufacturing com...

Laser Spot Detection Based on Reaction Diffusion

Directory of Open Access Journals (Sweden)

Alejandro Vázquez-Otero

2016-03-01

Full Text Available Center-location of a laser spot is a problem of interest when the laser is used for processing and performing measurements. Measurement quality depends on correctly determining the location of the laser spot. Hence, improving and proposing algorithms for the correct location of the spots are fundamental issues in laser-based measurements. In this paper we introduce a Reaction Diffusion (RD system as the main computational framework for robustly finding laser spot centers. The method presented is compared with a conventional approach for locating laser spots, and the experimental results indicate that RD-based computation generates reliable and precise solutions. These results confirm the flexibility of the new computational paradigm based on RD systems for addressing problems that can be reduced to a set of geometric operations.

Laser Spot Detection Based on Reaction Diffusion

OpenAIRE

Alejandro Vázquez-Otero; Danila Khikhlukha; J. M. Solano-Altamirano; Raquel Dormido; Natividad Duro

2016-01-01

Center-location of a laser spot is a problem of interest when the laser is used for processing and performing measurements. Measurement quality depends on correctly determining the location of the laser spot. Hence, improving and proposing algorithms for the correct location of the spots are fundamental issues in laser-based measurements. In this paper we introduce a Reaction Diffusion (RD) system as the main computational framework for robustly finding laser spot centers. The method presente...

Soft tissue deformation modelling through neural dynamics-based reaction-diffusion mechanics.

Science.gov (United States)

Zhang, Jinao; Zhong, Yongmin; Gu, Chengfan

2018-05-30

Soft tissue deformation modelling forms the basis of development of surgical simulation, surgical planning and robotic-assisted minimally invasive surgery. This paper presents a new methodology for modelling of soft tissue deformation based on reaction-diffusion mechanics via neural dynamics. The potential energy stored in soft tissues due to a mechanical load to deform tissues away from their rest state is treated as the equivalent transmembrane potential energy, and it is distributed in the tissue masses in the manner of reaction-diffusion propagation of nonlinear electrical waves. The reaction-diffusion propagation of mechanical potential energy and nonrigid mechanics of motion are combined to model soft tissue deformation and its dynamics, both of which are further formulated as the dynamics of cellular neural networks to achieve real-time computational performance. The proposed methodology is implemented with a haptic device for interactive soft tissue deformation with force feedback. Experimental results demonstrate that the proposed methodology exhibits nonlinear force-displacement relationship for nonlinear soft tissue deformation. Homogeneous, anisotropic and heterogeneous soft tissue material properties can be modelled through the inherent physical properties of mass points. Graphical abstract Soft tissue deformation modelling with haptic feedback via neural dynamics-based reaction-diffusion mechanics.

Exposure to secondhand smoke and associated factors among non-smoking pregnant women with smoking husbands in Sichuan province, China.

Science.gov (United States)

Yang, Lian; Tong, Elisa K; Mao, Zhengzhong; Hu, Teh-wei

2010-01-01

Secondhand smoke (SHS) exposure harms pregnant women and the fetus. China has the world's largest number of smokers and a high male smoking prevalence rate. To compare exposure to SHS among rural and urban Chinese non-smoking pregnant women with smoking husbands, and analyze factors associated with the level of SHS exposure and hair nicotine concentration. Sichuan province, China. In all 1,181 non-smoking pregnant women with smoking husbands recruited from eight district/county Women and Children's hospitals. The women completed a questionnaire in April and May 2008. Based on systematic sampling, 186 pregnant women were selected for sampling the nicotine concentration in their hair. Ordinal logistic regression analysis was conducted to examine correlates with self-reported SHS exposure (total and at home); linear regression was conducted for the sub-sample of hair nicotine concentrations. Secondhand smoking exposure rates, hair nicotine levels. About 75.1% of the non-smoking pregnant women with smoking husbands reported regular SHS exposure. The major source of exposure was through their husband. In the multivariate analysis, the risk of greater SHS exposure (total and at home) and hair nicotine concentration was increased for women who were rural, had a husband with greater cigarette consumption, less knowledge about SHS, less negative attitudes about SHS, and no smoke-free home rules. The high prevalence rate of SHS exposure suggests that it is important for non-smoking pregnant women, especially rural women, to establish smoke-free home rules and increase knowledge and negative attitudes towards SHS.

DNA-based catalytic enantioselective intermolecular oxa-Michael addition reactions

NARCIS (Netherlands)

Megens, Rik P.; Roelfes, Gerard

2012-01-01

Using the DNA-based catalysis concept, a novel Cu(II) catalyzed enantioselective oxa-Michael addition of alcohols to enones is reported. Enantioselectivities of up to 86% were obtained. The presence of water is important for the reactivity, possibly by reverting unwanted side reactions such as

ZrC Ceramics Prepared by Self-propagating High-temperature Synthesis/Single Action Pressing

Directory of Open Access Journals (Sweden)

CHENG Yong

2017-01-01

Full Text Available ZrC ceramics were prepared by mechanical axial compression of self-propagating high-temperature synthesis/single action pressing (SHS/SAP.The effects of pressure on microstructure and densification of the products,as well as the relationship between displacement/variation of the load curve and SHS reaction,were studied.The structure and properties of the products were investigated by XRD and SEM.In addition,the density was measured by the drain away liquid method.Meanwhile,universal testing machine was used to record the displacement and load curve alternations.The results indicate that products are mainly composed of ZrC phase,the process of exhaust are accelerated as the increasing of pressure as well,leading to the smaller size of porosity and crystal particles.Density manifested as an increasing pattern by the elevated pressure with no longer change at 80MPa.Due to the strong attenuation of pressure at the peak of temperature,the density of the production is only 65.7% in 120MPa.The end point of the SHS reaction and the plastic time of the products can be monitored by displacement and load curve.The results provide evidence for the application of self-propagating high-temperature synthesis/pseudo-hot isostatic pressing to further improve the density of ceramics.

Thermal runaway reaction hazards and mechanisms of hydroxylamine with acid/base contaminants

International Nuclear Information System (INIS)

Wei Chunyang; Saraf, Sanjeev R.; Rogers, William J.; Sam Mannan, M.

2004-01-01

Hydroxylamine (HA) has been involved in two incidents since 1999 because of its thermal instability and incompatibility. In this study, thermal runaway reactions of hydroxylamine with various concentrations of KOH and HCl were studied using the reactive system screening tool (RSST) and automatic pressure tracking adiabatic calorimeter (APTAC). The thermokinetic data, such as onset temperature, heat of reaction, maximum self-heat rate, maximum pressure rate, and non-condensable gas pressure, were compared with those of hydroxylamine solution without added impurity. Our study shows that the thermal decomposition behavior of hydroxylamine is affected by the presence of acid/base, and mixing of hydroxylamine with acid/base may cause thermal decomposition at lower temperatures. Different decomposition pathways can be initiated by hydrogen ion and hydroxide ion. The decomposition mechanisms of hydroxylamine in alkaline and acidic solutions are proposed based on the products, information from the literature, and quantum mechanical calculations. The experimental results are discussed in terms of the proposed reaction mechanisms

Chemical reactions on platinum-group metal surfaces studied by synchrotron-radiation-based spectroscopy

International Nuclear Information System (INIS)

Kondoh, Hiroshi; Nakai, Ikuyo; Nagasaka, Masanari; Amemiya, Kenta; Ohta, Toshiaki

2009-01-01

A new version of synchrotron-radiation-based x-ray spectroscopy, wave-length-dispersive near-edge x-ray absorption fine structure (dispersive-NEXAFS), and fast x-ray photoelectron spectroscopy have been applied to mechanistic studies on several surface catalytic reactions on platinum-group-metal surfaces. In this review, our approach using above techniques to understand the reaction mechanism and actual application studies on three well-known catalytic surface reactions, CO oxidation on Pt(111) and Pd(111), NO reduction on Rh(111), and H 2 O formation on Pt(111), are introduced. Spectroscopic monitoring of the progress of the surface reactions enabled us to detect reaction intermediates and analyze the reaction kinetics quantitatively which provides information on reaction order, rate constant, pre-exponential factor, activation energy and etc. Such quantitative analyses combined with scanning tunneling microscopy and kinetic Monte Carlo simulations revealed significant contribution of the adsorbate configurations and their dynamic changes to the reaction mechanisms of the above fundamental catalytic surface reactions. (author)

Indoor air quality in hospitality venues before and after implementation of a clean indoor air law--Western New York, 2003.

Science.gov (United States)

2004-11-12

Secondhand smoke (SHS) contains more than 50 carcinogens. SHS exposure is responsible for an estimated 3,000 lung cancer deaths and more than 35,000 coronary heart disease deaths among never smokers in the United States each year, and for lower respiratory infections, asthma, sudden infant death syndrome, and chronic ear infections among children. Even short-term exposures to SHS, such as those that might be experienced by a patron in a restaurant or bar that allows smoking, can increase the risk of experiencing an acute cardiovascular event. Although population-based data indicate declining SHS exposure in the United States over time, SHS exposure remains a common but preventable public health hazard. Policies requiring smoke-free environments are the most effective method of reducing SHS exposure. Effective July 24, 2003, New York implemented a comprehensive state law requiring almost all indoor workplaces and public places (e.g., restaurants, bars, and other hospitality venues) to be smoke-free. This report describes an assessment of changes in indoor air quality that occurred in 20 hospitality venues in western New York where smoking or indirect SHS exposure from an adjoining room was observed at baseline. The findings indicate that, on average, levels of respirable suspended particles (RSPs), an accepted marker for SHS levels, decreased 84% in these venues after the law took effect. Comprehensive clean indoor air policies can rapidly and effectively reduce SHS exposure in hospitality venues.

Factors associated with secondhand smoke incursion into the homes of non-smoking residents in a multi-unit housing complex: a cross-sectional study in Seoul, Korea

Directory of Open Access Journals (Sweden)

Jeonghoon Kim

2017-09-01

Full Text Available Abstract Background In a multi-unit housing (MUH complex, secondhand smoke (SHS can pass from one living space to another. The aim of this study was to determine the prevalence of SHS incursion, and to establish the relationship between SHS incursion and socio-demographic and built environmental factors in MUH in Korea. Methods A population-based sample of 2600 residents (aged ≥19 years living in MUH from across the city of Seoul, Korea, was obtained through a web-based selection panel. The residents completed a questionnaire detailing socio-demographic factors, smoking status, frequency of SHS incursion, and built environmental factors. The presence of a personal smoke-free home rule was determined by residents declaring that no one smoked inside the home. Results Of the 2600 participants, non-smoking residents who lived in homes with a personal smoke-free rule were selected for further analysis (n = 1784. In the previous 12 months, 74.7% of residents had experienced SHS incursion ≥1 times. A multivariate ordinal logistic regression analysis indicated that residents who spent more time at home, lived with children, supported the implementation of smoke-free regulations in MUH, lived in small homes, lived in homes with natural ventilation provided by opening a front door or the windows and front door, and lived in homes with more frequent natural ventilation were more likely to report SHS incursion into their homes. Conclusions The majority of the non-smoking residents experienced SHS incursion, even with a personal smoke-free rule in their homes. A smoke-free policy in MUH is needed to protect residents from SHS exposure when they are at home.

The COLIMA experiment on aerosol retention in containment leak paths under severe nuclear accidents

Energy Technology Data Exchange (ETDEWEB)

Parozzi, Flavio, E-mail: flavio.parozzi@rse-web.it [RSE, Power Generation Department, via Rubattino 54, I-20134 Milano (Italy); Caracciolo, Eduardo D.J., E-mail: eduardo.caracciolo@rse-web.it [RSE, Power Generation Department, via Rubattino 54, I-20134 Milano (Italy); Journeau, Christophe, E-mail: christophe.journeau@cea.fr [CEA Cadarache (France); Piluso, Pascal, E-mail: pascal.piluso@cea.fr [CEA Cadarache (France)

2013-08-15

Highlights: ► Experiment investigating aerosol retention within concrete containment cracks under nuclear severe accident conditions. ► Provided representative conditions of the aerosols suspended inside the containment of PWRs under a severe accident. ► Prototypical aerosol particles generated with a thermite reaction and transported through the crack sample reproducing surface characteristics, temperature, pressure drop and gas leakage. ► The results indicate the significant retention due to zig-zag path. -- Abstract: CEA and RSE managed an experimental research concerning the investigation of aerosol retention within concrete containment cracks under severe accident conditions. The main experiment was carried out in November 2008 with aerosol generated from the COLIMA facility and a sample of cracked concrete with defined geometric characteristics manufactured by RSE. The facility provided representative conditions of the aerosols suspended inside the containment of PWRs under a severe accident. Prototypical aerosol particles were generated with a thermite reaction and transported through the crack sample, where surface characteristics, temperature, pressure drop and gas leakage were properly reproduced. The paper describes the approach adopted for the preparation of the cracked concrete sample and the dimensioning of the experimental apparatus, the test procedure and the measured parameters. The preliminary results, obtained from this single test, are also discussed in the light of the present knowledge about aerosol phenomena and the theoretical analyses of particle behaviour with the crack path.

55 cases of allergic reactions to hair dye: a descriptive, consumer complaint-based study

DEFF Research Database (Denmark)

Søsted, H; Agner, T; Andersen, Klaus Ejner

2002-01-01

themselves, and adverse reactions to hair dye may not necessarily be recorded by the health care system, unless the reactions are especially severe. Based on this assumption, we suspected that hair dye dermatitis was occurring more frequently than reported in the literature. Consumer complaint-based data......Severe facial and scalp dermatitis following the use of permanent hair dyes has been reported in several cases. Para-phenylenediamine (PPD) is known as a potent contact allergen, and PPD is allowed in hair dye at a concentration of 6%. Hair dye reactions are usually diagnosed by the patients...

Synthesis of nano-sized amorphous boron powders through active dilution self-propagating high-temperature synthesis method

Energy Technology Data Exchange (ETDEWEB)

Wang, Jilin [The State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070 (China); Gu, Yunle [School of Material Science and Engineering, Wuhan Institute of Technology, Wuhan 430073 (China); Li, Zili [The State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070 (China); Wang, Weimin, E-mail: wangwm@hotmail.com [The State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070 (China); Fu, Zhengyi [The State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070 (China)

2013-06-01

Graphical abstract: Nano-sized amorphous boron powders were synthesized by active dilution self-propagating high-temperature synthesis (SHS) method. The effects of endothermic reaction rate, the possible chemical reaction mechanism and active dilution model for synthesis of the product were also discussed. Highlights: ► Nano-sized amorphous boron powders were synthesized by active dilution self-propagating high-temperature synthesis method. ► The morphology, particle size and purity of the samples could be effectively controlled via changing the endothermic rate. ► The diluter KBH{sub 4} played an important role in active dilution synthesis of amorphous nano-sized boron powders. ► The active dilution method could be further popularized and become a common approach to prepare various inorganic materials. - Abstract: Nano-sized amorphous boron powders were synthesized by active dilution self-propagating high-temperature synthesis (SHS) method at temperatures ranging from 700 °C to 850 °C in a SHS furnace using Mg, B{sub 2}O{sub 3} and KBH{sub 4} as raw materials. Samples were characterized by X-ray powder diffraction (XRD), Laser particle size analyzer, Fourier transform infrared spectra (FTIR), X-ray energy dispersive spectroscopy (EDX), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and high-resolution transmission TEM (HRTEM). The boron powders demonstrated an average particle size of 50 nm with a purity of 95.64 wt.%. The diluter KBH{sub 4} played an important role in the active dilution synthesis of amorphous nano-sized boron powders. The effects of endothermic reaction rate, the possible chemical reaction mechanism and active dilution model for synthesis of the product were also discussed.

Synthesis of nano-sized amorphous boron powders through active dilution self-propagating high-temperature synthesis method

International Nuclear Information System (INIS)

Wang, Jilin; Gu, Yunle; Li, Zili; Wang, Weimin; Fu, Zhengyi

2013-01-01

Graphical abstract: Nano-sized amorphous boron powders were synthesized by active dilution self-propagating high-temperature synthesis (SHS) method. The effects of endothermic reaction rate, the possible chemical reaction mechanism and active dilution model for synthesis of the product were also discussed. Highlights: ► Nano-sized amorphous boron powders were synthesized by active dilution self-propagating high-temperature synthesis method. ► The morphology, particle size and purity of the samples could be effectively controlled via changing the endothermic rate. ► The diluter KBH 4 played an important role in active dilution synthesis of amorphous nano-sized boron powders. ► The active dilution method could be further popularized and become a common approach to prepare various inorganic materials. - Abstract: Nano-sized amorphous boron powders were synthesized by active dilution self-propagating high-temperature synthesis (SHS) method at temperatures ranging from 700 °C to 850 °C in a SHS furnace using Mg, B 2 O 3 and KBH 4 as raw materials. Samples were characterized by X-ray powder diffraction (XRD), Laser particle size analyzer, Fourier transform infrared spectra (FTIR), X-ray energy dispersive spectroscopy (EDX), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and high-resolution transmission TEM (HRTEM). The boron powders demonstrated an average particle size of 50 nm with a purity of 95.64 wt.%. The diluter KBH 4 played an important role in the active dilution synthesis of amorphous nano-sized boron powders. The effects of endothermic reaction rate, the possible chemical reaction mechanism and active dilution model for synthesis of the product were also discussed

Association between current asthma and secondhand smoke exposure in vehicles among adults living in four US states.

Science.gov (United States)

Nguyen, Kimberly H; King, Brian A; Dube, Shanta R

2015-07-01

Many states have implemented laws prohibiting tobacco smoking in indoor public places. However, private settings remain a major source of secondhand smoke (SHS) exposure for many people. We assessed the association between current asthma and SHS exposure in vehicles among adult never-smokers in Indiana, Kentucky, Louisiana and Mississippi. Data came from the 2011 Behavioral Risk Factor Surveillance System, a state-based telephone survey of US adults aged ≥18 years. Analyses were restricted to states (n=4) that administered an optional SHS module. Prevalence of self-reported asthma and past 7-day SHS exposure in vehicles was calculated by demographics, voluntary smoke-free vehicle rules and SHS exposure in homes, public places and workplaces. Logistic regression was used to assess the adjusted association between asthma and SHS exposure in vehicles. Among 17 863 never-smoking adults, 7.4% reported having current asthma, whereas 12.3% reported past 7-day SHS exposure in vehicles. Among adults with asthma, SHS exposure in vehicles was lower among those with voluntary smoke-free rules compared with those without voluntary smoke-free rules (9.5% vs 56.7%, psmoke-free rules in vehicles, especially among adults with asthma. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Effect of Exposure to Second-Hand Smoke on the Quality of Life: A Nationwide Population-Based Study from South Korea.

Directory of Open Access Journals (Sweden)

Yeon Wook Kim

Full Text Available Although exposure to second-hand smoke (SHS has been associated with various medical conditions, only limited data are available on its association with health-related quality of life (HRQOL, particularly data obtained with the EQ-5D or EQ visual analogue scale (VAS.This cross-sectional study evaluated 10,532 adult never-smokers who participated in the fifth Korea National Health and Nutrition Examination Survey. By using linear regression models to adjust for possible confounders and incorporating survey weights in analyses, the association between exposure to SHS and HRQOL-measured with the EQ-5D index and the EQ-VAS score-was evaluated. Data were further stratified by the amount of exposure time.After weighted analysis and adjustment, exposure to SHS was significantly associated with lower measures on the EQ-5D index (β = -0.007, P = 0.005 and EQ-VAS score (β = -1.936, P < 0.001. When comparing the unexposed group with the groups exposed <2h/day and ≥2h/day, exposure to a longer duration of SHS was significantly associated with lower scores on the EQ-5D index and the EQ-VAS score.In conclusion, exposure to SHS was associated with reduced HRQOL measured by the EQ-5D index and EQ-VAS score, revealing a dose-response relationship.

Integrated Modeling and Experimental Studies at the Meso Scale for Advanced Reactive Materials

Science.gov (United States)

2016-07-01

CuO) thermite, and the metal/intermetallic system composed of titanium, silicon, and tita - nium, boron. A typical shock compaction experiment is...intense and weak chemical reactions recurring within a time interval of approximately 100 µ s. Similar results were observed for the tita - nium...region where there is only tita - nium (x < xf), from a region where there is only boron (x > xf). Since Y2 = 0 for x < xf, we find that a1 = −D13, b1

Secondhand smoke exposure and susceptibility to initiating cigarette smoking among never-smoking students in selected African countries: Findings from the Global Youth Tobacco Survey.

Science.gov (United States)

Lee, Kyung A; Palipudi, Krishna M; English, Lorna M; Ramanandraibe, Nivo; Asma, Samira

2016-10-01

Exposure to secondhand smoke (SHS) causes premature death and illness in non-smokers. We examined SHS exposure at home and in public places, as well as susceptibility to initiate cigarette smoking among never cigarette smokers. We used 2006-2011 Global Youth Tobacco Survey (GYTS) data from 29 African countries (56,967 students). GYTS is a nationally representative, self-administered school-based survey, conducted among students aged 13-15years. Prevalence ratio, estimates and 95% confidence intervals were computed for SHS exposure in the homes and public places separately. The two-sample t-test was used to assess the difference in susceptibility to smoking by SHS exposure among never-smoking students (α=0.05). Among never-smoking students, exposure to SHS at home ranged from 12.7% (Cape Verde) to 44.0% (Senegal). The prevalence ratio (PR) comparing susceptibility to smoking initiation among never smokers exposed to SHS at home to those who were not exposed at home ranged from 1.2 to 2.6. Exposure to SHS in public places ranged from 23.9% (Cape Verde) to 80.4% (Mali). Of the countries being studied, 8 countries showed a significant difference in susceptibility to smoking initiation among never smokers exposed to SHS in public places compared to those not exposed in public places. (PR ranged from 0.5-3.5). In many African countries in the study, a substantial proportion of students who never smoked are exposed to SHS at home and in public places. Majority of never smokers who were exposed to SHS at home and in public places had a higher prevalence of susceptibility to initiate smoking than those that were not exposed to SHS at home and in public places. Adoption and enforcement of smoke-free policies in public places and smoke-free rules at home could substantially contribute to reducing SHS exposure in many of these countries. Copyright © 2016 Elsevier Inc. All rights reserved.

Linear friction welding for constructing and repairing rail for high speed and intercity passenger service rail : final report.

Science.gov (United States)

2016-08-01

This project developed a solid-state welding process based on linear friction welding (LFW) technology. While resistance flash welding or : thermite techniques are tried and true methods for joining rails and performing partial rail replacement repai...

Driving Ability of HMX based Aluminized Explosive Affected by the Reaction Degree of Aluminum Powder

Science.gov (United States)

Duan, Yingliang

2017-06-01

Due to the time scale of aluminum reaction, the detonation process of the aluminized explosive becomes very complex, and there is less agreement on the reaction mechanism of aluminum powder. If the reaction of aluminum occurs in the reaction zone, the energy released will further strengthen the work ability of detonation wave. So it is very important for characterizing the detonation parameters and detonation driving ability to accurately understand the role of aluminum powder in the reaction zone. In this paper, detonation driving process of HMX based aluminized explosive was studied by cylinder test, obtaining the expansion track of cylinder wall. In order to further research the reaction degree (λ) of aluminum in the reaction zone, the thermodynamic program VHL was used to calculate the detonation process at different reaction degrees, obtaining the parameters of detonation products thermodynamic state. Using the dynamic software LS-DYNA and the JWL equation of state by fitting the pressure and relative volume relationship, the cylinder test was simulated. Compared with the experimental results, when the reaction degree is 20%, the driving ability is found to be in agreement with measured ones. It is concluded that the driving ability of HMX based aluminized explosive can be more accurately characterized by considering the reaction degree of aluminum powder in the reaction zone.

Measurement of reaction heats using a polysilicon-based microcalorimetric sensor

NARCIS (Netherlands)

Vereshchagina, E.; Wolters, Robertus A.M.; Gardeniers, Johannes G.E.

2011-01-01

In this work we present a low-cost, low-power, small sample volume microcalorimetric sensor for the measurement of reaction heats. The polysilicon-based microcalorimetric sensor combines several advantages: (i) complementary metal oxide semiconductor technology (CMOS) for future integration; (ii)

Socioeconomic Inequalities in Secondhand Smoke Exposure at Home and at Work in 15 Low- and Middle-Income Countries.

Science.gov (United States)

Nazar, Gaurang P; Lee, John Tayu; Arora, Monika; Millett, Christopher

2016-05-01

In high-income countries, secondhand smoke (SHS) exposure is higher among disadvantaged groups. We examine socioeconomic inequalities in SHS exposure at home and at workplace in 15 low- and middle-income countries (LMICs). Secondary analyses of cross-sectional data from 15 LMICs participating in Global Adult Tobacco Survey (participants ≥ 15 years; 2008-2011) were used. Country-specific analyses using regression-based methods were used to estimate the magnitude of socioeconomic inequalities in SHS exposure: (1) Relative Index of Inequality and (2) Slope Index of Inequality. SHS exposure at home ranged from 17.4% in Mexico to 73.1% in Vietnam; exposure at workplace ranged from 16.9% in Uruguay to 65.8% in Bangladesh. In India, Bangladesh, Thailand, Malaysia, Philippines, Vietnam, Uruguay, Poland, Turkey, Ukraine, and Egypt, SHS exposure at home reduced with increasing wealth (Relative Index of Inequality range: 1.13 [95% confidence interval [CI] 1.04-1.22] in Turkey to 3.31 [95% CI 2.91-3.77] in Thailand; Slope Index of Inequality range: 0.06 [95% CI 0.02-0.11] in Turkey to 0.43 [95% CI 0.38-0.48] in Philippines). In these 11 countries, and in China, SHS exposure at home reduced with increasing education. In India, Bangladesh, Thailand, and Philippines, SHS exposure at workplace reduced with increasing wealth. In India, Bangladesh, Thailand, Philippines, Vietnam, Poland, Russian Federation, Turkey, Ukraine, and Egypt, SHS exposure at workplace reduced with increasing education. SHS exposure at homes is higher among the socioeconomically disadvantaged in the majority of LMICs studied; at workplaces, exposure is higher among the less educated. Pro-equity tobacco control interventions alongside targeted efforts in these groups are recommended to reduce inequalities in SHS exposure. SHS exposure is higher among the socioeconomically disadvantaged groups in high-income countries. Comprehensive smoke-free policies are pro-equity for certain health outcomes that are

Socioeconomic Inequalities in Secondhand Smoke Exposure at Home and at Work in 15 Low- and Middle-Income Countries

Science.gov (United States)

Lee, John Tayu; Arora, Monika; Millett, Christopher

2016-01-01

Introduction: In high-income countries, secondhand smoke (SHS) exposure is higher among disadvantaged groups. We examine socioeconomic inequalities in SHS exposure at home and at workplace in 15 low- and middle-income countries (LMICs). Methods: Secondary analyses of cross-sectional data from 15 LMICs participating in Global Adult Tobacco Survey (participants ≥ 15 years; 2008–2011) were used. Country-specific analyses using regression-based methods were used to estimate the magnitude of socioeconomic inequalities in SHS exposure: (1) Relative Index of Inequality and (2) Slope Index of Inequality. Results: SHS exposure at home ranged from 17.4% in Mexico to 73.1% in Vietnam; exposure at workplace ranged from 16.9% in Uruguay to 65.8% in Bangladesh. In India, Bangladesh, Thailand, Malaysia, Philippines, Vietnam, Uruguay, Poland, Turkey, Ukraine, and Egypt, SHS exposure at home reduced with increasing wealth (Relative Index of Inequality range: 1.13 [95% confidence interval [CI] 1.04–1.22] in Turkey to 3.31 [95% CI 2.91–3.77] in Thailand; Slope Index of Inequality range: 0.06 [95% CI 0.02–0.11] in Turkey to 0.43 [95% CI 0.38–0.48] in Philippines). In these 11 countries, and in China, SHS exposure at home reduced with increasing education. In India, Bangladesh, Thailand, and Philippines, SHS exposure at workplace reduced with increasing wealth. In India, Bangladesh, Thailand, Philippines, Vietnam, Poland, Russian Federation, Turkey, Ukraine, and Egypt, SHS exposure at workplace reduced with increasing education. Conclusion: SHS exposure at homes is higher among the socioeconomically disadvantaged in the majority of LMICs studied; at workplaces, exposure is higher among the less educated. Pro-equity tobacco control interventions alongside targeted efforts in these groups are recommended to reduce inequalities in SHS exposure. Implications: SHS exposure is higher among the socioeconomically disadvantaged groups in high-income countries. Comprehensive smoke

One-electron oxidation reactions of purine and pyrimidine bases in cellular DNA.

Science.gov (United States)

Cadet, Jean; Wagner, J Richard; Shafirovich, Vladimir; Geacintov, Nicholas E

2014-06-01

The aim of this survey is to critically review the available information on one-electron oxidation reactions of nucleobases in cellular DNA with emphasis on damage induced through the transient generation of purine and pyrimidine radical cations. Since the indirect effect of ionizing radiation mediated by hydroxyl radical is predominant in cells, efforts have been made to selectively ionize bases using suitable one-electron oxidants that consist among others of high intensity UVC laser pulses. Thus, the main oxidation product in cellular DNA was found to be 8-oxo-7,8-dihydroguanine as a result of direct bi-photonic ionization of guanine bases and indirect formation of guanine radical cations through hole transfer reactions from other base radical cations. The formation of 8-oxo-7,8-dihydroguanine and other purine and pyrimidine degradation products was rationalized in terms of the initial generation of related radical cations followed by either hydration or deprotonation reactions in agreement with mechanistic pathways inferred from detailed mechanistic studies. The guanine radical cation has been shown to be implicated in three other nucleophilic additions that give rise to DNA-protein and DNA-DNA cross-links in model systems. Evidence was recently provided for the occurrence of these three reactions in cellular DNA. There is growing evidence that one-electron oxidation reactions of nucleobases whose mechanisms have been characterized in model studies involving aqueous solutions take place in a similar way in cells. It may also be pointed out that the above cross-linked lesions are only produced from the guanine radical cation and may be considered as diagnostic products of the direct effect of ionizing radiation.

Multi-dimensional modeling of two-phase flow in rod bundles and interpretation of velocities measured in BWRs by the cross-correlation technique

International Nuclear Information System (INIS)

Analytis, G.Th.; Luebbesmeyer, D.

1984-04-01

The authors present an as precise as possible interpretation of velocity measurements in BWRs by the cross-correlation technique, which is based on the radially non-uniform quality and velocity distribution in BWR type bundles, as well as on our knowledge about the spatial 'field of view' of the in-core neutron detectors. After formulating the three-dimensional two-fluid model volume/time averaged equations and pointing out some problems associated with averaging, they expound a little on the turbulence mixing and void drift effects, as well as on the way they are modelled in advanced subchannel analysis codes like THERMIT or COBRA-TF. Subsequently, some comparisons are made between axial velocities measured in a commercial BWR by neutron noise analysis, and the steam velocities of the four subchannels nearest to the instrument tube of one of the four bundles as predicted by COBRA-III and by THERMIT. Although as expected, for well-known reasons, COBRA-III predicts subchannel steam velocities which are close to each other, THERMIT correctly predicts in the upper half of the core three largely different steam velocities in the three different types of BW0 subchannels (corner, edge and interior). (Auth.)

Secondhand tobacco smoke exposure among adolescents in an Ethiopian school

Directory of Open Access Journals (Sweden)

Sabit Abazinab Ababulgu

2016-05-01

Full Text Available Tobacco use is responsible for 6 million deaths globally per year, of which 600,000 deaths are due to secondhand smoke (SHS mainly among women and children. This study aims to determine the prevalence of SHS exposure among school-going adolescents and highlights the essential determinants in developing successful strategies to prevent adverse health effects in Ethiopia. The analysis is based on a school based cross sectional study where 1673 students with 98.2% of response rate from grade 9-12, aged 13-19 were included. Data was collected by a self-administered questionnaire that is adapted from the global youth tobacco survey questionnaire. Proportions and 95% confidence intervals were obtained as estimates of prevalence. Bivariate and multivariate analyses were made using logistic regression on SPSS version 20.0 software in order to predict factors associated with SHS exposure. About 17% of adolescents were exposed to tobacco smoke in their home, whereas more than half (60.8% of adolescents were exposed to tobacco smoke in public places. In multivariate analysis, sex, parent smoking, peer smoking, and absence of discussion in the classroom about dangers of smoking were seen significantly associated with SHS exposure. The prevalence of SHS exposure among adolescents in Ethiopia is highest. Moreover, exposure to SHS in public places is much higher than at home.

Tobacco Use and Exposure to Second-Hand Smoke among Urban Residents: A Community-Based Investigation

Directory of Open Access Journals (Sweden)

Zhaorui Xu

2015-08-01

Full Text Available Objectives: In 2005, China acceded to the World Health Organization Framework Convention on Tobacco Control (WHO FCTC, the foundation for the global fight against tobacco. Certain cities in China have established local regulations to control tobacco use ahead of national policy; however, without the enforcement of statutory law, some of these regulations are merely lip service. The aim of the study was to assess the effects of city policy on smoking prevalence and on second-hand smoke (SHS exposure status among non-smokers in Changchun City. Methods: A cross-sectional survey covering a multiple-stage, representative sample of the urban population aged ≥15 years was conducted between 1 Dec 2013 and 31 Jan 2014. The WHO and the US Centers for Disease Control and Prevention developed the questionnaires used, which included demographic characteristics, smoking behaviors and SHS exposure status. Results: Overall cigarette smoking prevalence was 23.5%; daily cigarette smoking prevalence was 21.2%. Smoking prevalence and cigarettes consumed per day was higher among men (p < 0.05 and those aged 45–64 years (p < 0.05. Among current smokers, 8.1% planned to quit within 12 months; 53.4% had no intention of quitting. Overall SHS exposure prevalence was 41.9% (workplace and 34.1% (at home over the previous 30 days. The weighted workplace SHS exposure prevalence increased with age. Conclusions: The high proportion of smokers with no intention of quitting and the high level of SHS exposure may constitute one of the most significant barriers to successful smoking cessation in the city. A continued drive to promote full implementation of the WHO FCTC is still needed.

[New Scientific Evidence-based Public Health Guidelines and Practical Manual for Prevention of Sick House Syndrome].

Science.gov (United States)

Kishi, Reiko; Yoshino, Hiroshi; Araki, Atsuko; Saijo, Yasuaki; Azuma, Kenichi; Kawai, Toshio; Yamato, Hiroshi; Osawa, Haruki; Shibata, Eiji; Tanaka, Masatoshi; Masuchi, Ayumi; Minatoya, Machiko; Ait Bamai, Yu

2018-01-01

Recently, we have published a book containing evidence-based public health guidelines and a practical manual for the prevention of sick house syndrome. The manual is available through the homepage of the Ministry of Health, Labour and Welfare (http://www.mhlw.go.jp/file/06-Seisakujouhou-11130500-Shokuhinanzenbu/0000155147.pdf). It is an almost completely revised version of the 2009 version. The coauthors are 13 specialists in environmental epidemiology, exposure sciences, architecture, and risk communication. Since the 1970s, health problems caused by indoor chemicals, biological pollution, poor temperature control, humidity, and others in office buildings have been recognized as sick building syndrome (SBS) in Western countries, but in Japan it was not until the 1990s that people living in new or renovated homes started to describe a variety of nonspecific subjective symptoms such as eye, nose, and throat irritation, headache, and general fatigue. These symptoms resembled SBS and were designated "sick house syndrome (SHS)." To determine the strategy for prevention of SHS, we conducted a nationwide epidemiological study in six cities from 2003-2013 by randomly sampling 5,709 newly built houses. As a result 1,479 residents in 425 households agreed to environmental monitoring for indoor aldehydes and volatile organic compounds (VOCs). After adjustment for possible risk factors, some VOCs and formaldehyde were dose-dependently shown to be significant risk factors. We also studied the dampness of the houses, fungi, allergies, and others. This book is fully based on the scientific evidence collected through these studies and other newly obtained information, especially from the aspect of architectural engineering. In addition to SHS, we included chapters on recent information about "multi-chemical sensitivity."

New Trends in Research of Energetic Materials (5th Seminar) Held in Pardubice, Czech Republic on 24-25 Apr 2002

Science.gov (United States)

2002-04-01

Zielonka, POLAND CONTA CT COMPA TIRILITYINVESTIGA TIONS OF HIGH-ENER GE TIC MA TERIALS USED IN’MORTAR A UGMENTING PROPELLI7VG CHARGES 200 Joel ...Proceeding of the V. Seminar IRON OXIDE/ALUMINUM FAST THERMITE REACTION USING NITRATE ADITIVES Joel Morgado*, Luisa Durfes**, Jos6 Campos* and Ant6nio...fctwi..0.00400 - ___ ___________ .5. - Cobi _ - 0__ 4.50 C t0C 1. ________-01.6 0.000 0.000 0.010 0.015 0.020 0.025 0.010 0.035 0.040 01045 Mow0

‘Only Fathers Smoking’ Contributes the Most to Socioeconomic Inequalities: Changes in Socioeconomic Inequalities in Infants’ Exposure to Second Hand Smoke over Time in Japan

Science.gov (United States)

Saito, Junko; Tabuchi, Takahiro; Shibanuma, Akira; Yasuoka, Junko; Nakamura, Masakazu; Jimba, Masamine

2015-01-01

Background Exposure to second hand smoke (SHS) is one of the major causes of premature death and disease among children. While socioeconomic inequalities exist for adult smoking, such evidence is limited for SHS exposure in children. Thus, this study examined changes over time in socioeconomic inequalities in infants’ SHS exposure in Japan. Methods This is a repeated cross-sectional study of 41,833 infants born in 2001 and 32,120 infants born in 2010 in Japan from nationally representative surveys using questionnaires. The prevalence of infants’ SHS exposure was determined and related to household income and parental education level. The magnitudes of income and educational inequalities in infants’ SHS exposure were estimated in 2001 and 2010 using both absolute and relative inequality indices. Results The prevalence of SHS exposure in infants declined from 2001 to 2010. The relative index of inequality increased from 0.85 (95% confidence interval [CI], 0.80 to 0.89) to 1.47 (95% CI, 1.37 to 1.56) based on income and from 1.22 (95% CI, 1.17 to 1.26) to 2.09 (95% CI, 2.00 to 2.17) based on education. In contrast, the slope index of inequality decreased from 30.9 (95% CI, 29.3 to 32.6) to 20.1 (95% CI, 18.7 to 21.5) based on income and from 44.6 (95% CI, 43.1 to 46.2) to 28.7 (95% CI, 27.3 to 30.0) based on education. Having only a father who smoked indoors was a major contributor to absolute income inequality in infants’ SHS exposure in 2010, which increased in importance from 45.1% in 2001 to 67.0% in 2010. Conclusions The socioeconomic inequalities in infants’ second hand smoke exposure increased in relative terms but decreased in absolute terms from 2001 to 2010. Further efforts are needed to encourage parents to quit smoking and protect infants from second hand smoke exposure, especially in low socioeconomic households that include non-smoking mothers. PMID:26431400

'Only Fathers Smoking' Contributes the Most to Socioeconomic Inequalities: Changes in Socioeconomic Inequalities in Infants' Exposure to Second Hand Smoke over Time in Japan.

Science.gov (United States)

Saito, Junko; Tabuchi, Takahiro; Shibanuma, Akira; Yasuoka, Junko; Nakamura, Masakazu; Jimba, Masamine

2015-01-01

Exposure to second hand smoke (SHS) is one of the major causes of premature death and disease among children. While socioeconomic inequalities exist for adult smoking, such evidence is limited for SHS exposure in children. Thus, this study examined changes over time in socioeconomic inequalities in infants' SHS exposure in Japan. This is a repeated cross-sectional study of 41,833 infants born in 2001 and 32,120 infants born in 2010 in Japan from nationally representative surveys using questionnaires. The prevalence of infants' SHS exposure was determined and related to household income and parental education level. The magnitudes of income and educational inequalities in infants' SHS exposure were estimated in 2001 and 2010 using both absolute and relative inequality indices. The prevalence of SHS exposure in infants declined from 2001 to 2010. The relative index of inequality increased from 0.85 (95% confidence interval [CI], 0.80 to 0.89) to 1.47 (95% CI, 1.37 to 1.56) based on income and from 1.22 (95% CI, 1.17 to 1.26) to 2.09 (95% CI, 2.00 to 2.17) based on education. In contrast, the slope index of inequality decreased from 30.9 (95% CI, 29.3 to 32.6) to 20.1 (95% CI, 18.7 to 21.5) based on income and from 44.6 (95% CI, 43.1 to 46.2) to 28.7 (95% CI, 27.3 to 30.0) based on education. Having only a father who smoked indoors was a major contributor to absolute income inequality in infants' SHS exposure in 2010, which increased in importance from 45.1% in 2001 to 67.0% in 2010. The socioeconomic inequalities in infants' second hand smoke exposure increased in relative terms but decreased in absolute terms from 2001 to 2010. Further efforts are needed to encourage parents to quit smoking and protect infants from second hand smoke exposure, especially in low socioeconomic households that include non-smoking mothers.

Smoking, secondhand smoke, and cotinine levels in a subset of EPIC cohort

NARCIS (Netherlands)

Baltar, V.T.; Xun, W.W.; Chuang, S.C.; Relton, C.; Ueland, P.M.; Vollset, S.E.; Midttun, O.; Johansson, M.; Slimani, N.; Jenab, M.; Boshuizen, H.C.

2011-01-01

Background: Several countries are discussing new legislation regarding the ban on smoking in public places, based on the growing evidence of the hazards of secondhand smoke (SHS) exposure. The objective of the present study is to quantitatively assess the relationship between smoking, SHS, and serum

Smoking, Secondhand Smoke, and Cotinine Levels in a Subset of EPIC Cohort

NARCIS (Netherlands)

Baltar, Valeria Troncoso; Xun, Wei W.; Chuang, Shu-Chun; Relton, Caroline; Ueland, Per Magne; Vollset, Stein Emil; Midttun, Oivind; Johansson, Mattias; Slimani, Nadia; Jenab, Mazda; Clavel-Chapelon, Francoise; Boutron-Ruault, Marie-Christine; Fagherazzi, Guy; Kaaks, Rudolf; Rohrmann, Sabine; Boeing, Heiner; Weikert, Cornelia; Bueno-de-Mesquita, H. Bas; Boshuizen, Hendriek C.; van Gils, Carla H.; Peeters, Petra H. M.; Agudo, Antonio; Barricarte, Aurelio; Navarro, Carmen; Rodriguez, Laudina; Huerta Castano, Jose Maria; Larranaga, Nerea; Sanchez Perez, Maria Jose; Khaw, Kay-Tee; Wareham, Nick; Allen, Naomi E.; Crowe, Francesca; Gallo, Valentina; Norat, Teresa; Tagliabue, Giovanna; Masala, Giovanna; Panico, Salvatore; Sacerdote, Carlota; Tumino, Rosario; Trichopoulou, Antonia; Lagiou, Pagona; Bamia, Christina; Rasmuson, Torgny; Hallmans, Goran; Roswall, Nina; Tjonneland, Anne; Riboli, Elio; Brennan, Paul; Vineis, Paolo

Background: Several countries are discussing new legislation regarding the ban on smoking in public places, based on the growing evidence of the hazards of secondhand smoke (SHS) exposure. The objective of the present study is to quantitatively assess the relationship between smoking, SHS, and serum

The economic burden of smoking and secondhand smoke exposure in rural South-West China.

Science.gov (United States)

Cai, Le; Cui, Wenlong; He, Jianhui; Wu, Xinan

2014-06-01

To estimate the direct and indirect costs of chronic diseases attributed to smoking and exposure to secondhand smoke (SHS) in a given year (2011) in rural southwest China. A prevalence-based, disease-specific attributable-risk approach was used to estimate the economic burden of chronic diseases attributable to both smoking and exposure to secondhand smoke (SHS). A cross-sectional questionnaire survey of 17 158 consenting adults aged ≥18 years was used to derive prevalence of smoking and exposure to SHS, as well as direct and indirect costs of chronic diseases. In the study population, the prevalence rates of smoking and exposure to SHS are 73.1 and 38.2% for males and 1.4 and 43.4% for females, respectively. The total costs of illness are $25.85 million for COPD, $18.80 million for asthma, $37.25 million for CHD, $17.91 million for stroke, $264.35 million for hypertension and $17.11 million for peptic ulcer. The estimated costs attributable to smoking and exposure to SHS are $95.51 million and $79.35 million, accounting for 7.15 and 5.94% of local healthcare costs, respectively. Of the total costs of tobacco, direct costs and indirect costs are $94.66 million and $0.85 million for smoking, and $78.22 million and $1.36 million for exposure to SHS. Smoking contributes more cost of illness than exposure to SHS in men, whereas exposure to SHS contributes more cost of illness than smoking in women. Smoking and exposure to SHS produce substantial economic burden as well as have a considerable public health impact in rural southwest China.

An Unexpected Reaction between 5-Hydroxymethylfurfural and Imidazolium-Based Ionic Liquids at High Temperatures

Directory of Open Access Journals (Sweden)

Zongbao K. Zhao

2011-10-01

Full Text Available A new compound was detected during the production of 5-hydroxymethylfurfural (HMF from glucose and cellulose in the ionic liquid 1-butyl-3-methylimidazolium chloride ([Bmim]Cl at high temperatures. Further experiments found that it was derived from the reaction of HMF with [Bmim]Cl. The structure of new compound was established as 1-butyl-2-(5’-methyl-2’-furoylimidazole (BMI based on nuclear magnetic resonance and mass spectrometry analysis, and a possible mechanism for its formation was proposed. Reactions of HMF with other imidazolium-based ionic liquids were performed to check the formation of BMI. Our results provided new insights in terms of side reactions between HMF and imidazolium-based ionic liquids, which should be valuable for designing better processes for the production of furans using biomass and related materials.

Nanodiamond for tuning the properties of energetic composites.

Science.gov (United States)

Pichot, Vincent; Comet, Marc; Miesch, Julien; Spitzer, Denis

2015-12-30

Bismuth oxide (Bi2O3) particles were coated by detonation nanodiamonds. The resulting nanocomposite materials were mixed with an aluminum nanopowder (≈ 100 nm) to prepare nanothermites, with reduced sensitivity to friction and electrostatic discharge (ESD). The use of nanodiamond for this purpose is reported here for the first time. Their numerous qualities such as their small size, antifriction properties and thermal conductivity make them ideal candidates. Small amounts of detonation nanodiamonds allow obtaining impressive desensitization, making thus modified Bi2O3/Al nanothermite safe to handle. A composition containing around 1 wt.% of nanodiamond has a sensitivity threshold to friction superior to 100 N instead of 5 N for the thermite without nanodiamond. Furthermore, the sensitivity threshold to electrostatic discharge increases to 20 times when the nanodiamond content reaches 1.8 wt.%. The antifriction properties of nanodiamond limit the scratching of Bi2O3 surface by Al particles. The desensitization to ESD is observed for a sufficient coverage of the oxide particles (1.8 wt.% of ND), which restrains the effect of the melt dispersion mechanism of aluminum and prevents the mixing of the oxidizing and the reducing parts of the composites. A good reactivity of the thermite could be maintained for nanodiamond content up to 2.6 wt.%. The carburizing of aluminum coming on contact with nanodiamond during the thermite reaction could be evidenced by X-ray Diffraction and calorimetry measurements and also participates to the desensitization of the nanothermite. This kind of desensitization by using detonation nanodiamond can also be applied to other nanothermites having low sensitivity threshold to friction and ESD. Copyright © 2015 Elsevier B.V. All rights reserved.

Liquid chromatography/tandem mass spectrometry method for quantitative estimation of solutol HS15 and its applications

OpenAIRE

Bhaskar, V. Vijaya; Middha, Anil; Srivastava, Pratima; Rajagopal, Sriram

2015-01-01

A rapid, sensitive and selective pseudoMRM (pMRM)-based method for the determination of solutol HS15 (SHS15) in rat plasma was developed using liquid chromatography/tandem mass spectrometry (LCâMS/MS). The most abundant ions corresponding to SHS15 free polyethyleneglycol (PEG) oligomers at m/z 481, 525, 569, 613, 657, 701, 745, 789, 833, 877, 921 and 965 were selected for pMRM in electrospray mode of ionization. Purity of the lipophilic and hydrophilic components of SHS15 was estimated using ...

Weak Acid Ionization Constants and the Determination of Weak Acid-Weak Base Reaction Equilibrium Constants in the General Chemistry Laboratory

Science.gov (United States)

Nyasulu, Frazier; McMills, Lauren; Barlag, Rebecca

2013-01-01

A laboratory to determine the equilibrium constants of weak acid negative weak base reactions is described. The equilibrium constants of component reactions when multiplied together equal the numerical value of the equilibrium constant of the summative reaction. The component reactions are weak acid ionization reactions, weak base hydrolysis…

Task 9. Photovoltaic deployment in developing countries. Financing mechanisms for solar home systems in developing countries. The role of financing in the dissemination process

Energy Technology Data Exchange (ETDEWEB)

Scheutzlich, T.; Pertz, K.; Klinghammer, W.; Scholand, M.; Wisniwski, S.

2002-09-15

This report for the International Energy Agency (IEA) made by Task 9 of the Photovoltaic Power Systems (PVPS) programme takes a look at the implementation of Solar Home Systems in developing countries. The objective of Task 9 is to increase the successful deployment of PV systems in developing countries. This paper takes a look at financing mechanisms for Solar Home Systems (SHS). The lack of financial services for users of SHS is often regarded as the main barrier for their commercial dissemination and is often the justification for donor assisted programmes. This study attempts to shed some light on the question whether commercial SHS dissemination in remote rural areas could be made easier if financial services were made available. The authors state that the thesis is based on the fact that carefully designed, target-group-oriented financial services may speed up the widespread dissemination of SHS. Financial mechanisms for the stimulation of SHS and how their commercialisation can be achieved are among the topics discussed.

TITAN: an advanced three-dimensional neutronics/thermal-hydraulics code for light water reactor safety analysis

International Nuclear Information System (INIS)

Griggs, D.P.; Kazimi, M.S.; Henry, A.F.

1982-01-01

The initial development of TITAN, a three-dimensional coupled neutronics/thermal-hydraulics code for LWR safety analysis, has been completed. The transient neutronics code QUANDRY has been joined to the two-fluid thermal-hydraulics code THERMIT with the appropriate feedback mechanisms modeled. A detailed steady-state and transient coupling scheme based on the tandem technique was implemented in accordance with the important structural and operational characteristics of QUANDRY and THERMIT. A two channel sample problem formed the basis for steady-state and transient analyses performed with TITAN. TITAN steady-state results were compared with those obtained with MEKIN and showed good agreement. Null transients, simulated turbine trip transients, and a rod withdrawal transient were analyzed with TITAN and reasonable results were obtained

Clear Skies and Grey Areas: Flight Attendants' Secondhand Smoke Exposure and Attitudes toward Smoke-Free Policy 25 Years since Smoking was Banned on Airplanes.

Science.gov (United States)

Stillman, Frances A; Soong, Andrea; Zheng, Laura Y; Navas-Acien, Ana

2015-06-04

Our objective was to provide descriptive data on flight attendant secondhand smoke (SHS) exposure in the work environment, and to examine attitudes toward SHS exposure, personal health, and smoke-free policy in the workplace and public places. Flight attendants completed a web-based survey of self-reported SHS exposure and air quality in the work environment. We assessed the frequency and duration of SHS exposure in distinct areas of the workplace, attitudes toward SHS exposure and its health effects, and attitudes toward smoke-free policy in the workplace as well as general public places. A total of 723 flight attendants participated in the survey, and 591 responded to all survey questions. The mean level of exposure per flight attendant over the past month was 249 min. The majority of participants reported being exposed to SHS always/often in outdoor areas of an airport (57.7%). Participants who worked before the in-flight smoking ban (n=240) were more likely to support further smoking policies in airports compared to participants who were employed after the ban (n=346) (76.7% versus 60.4%, p-valuesmoke-free policies and want to see further restrictions in airports and public places.

Liquid chromatography/tandem mass spectrometry method for quantitative estimation of solutol HS15 and its applications

Directory of Open Access Journals (Sweden)

V. Vijaya Bhaskar

2015-04-01

Full Text Available A rapid, sensitive and selective pseudoMRM (pMRM-based method for the determination of solutol HS15 (SHS15 in rat plasma was developed using liquid chromatography/tandem mass spectrometry (LC–MS/MS. The most abundant ions corresponding to SHS15 free polyethyleneglycol (PEG oligomers at m/z 481, 525, 569, 613, 657, 701, 745, 789, 833, 877, 921 and 965 were selected for pMRM in electrospray mode of ionization. Purity of the lipophilic and hydrophilic components of SHS15 was estimated using evaporative light scattering detector (ELSD. Plasma concentrations of SHS15 were measured after oral administration at 2.50 g/kg dose and intravenous administration at 1.00 g/kg dose in male Sprague Dawley rats. SHS15 has poor oral bioavailability of 13.74% in rats. Differences in pharmacokinetics of oligomers were studied. A novel proposal was conveyed to the scientific community, where formulation excipient could be analyzed as a qualifier in the analysis of new chemical entities (NCEs to address the spiky plasma concentration profiles. Keywords: SHS15, LC–MS/MS, Spiky profiles, Validation

Second-hand smoke exposure in 4-year-old children in Spain: Sources, associated factors and urinary cotinine.

Science.gov (United States)

Aurrekoetxea, Juan José; Murcia, Mario; Rebagliato, Marisa; Guxens, Mònica; Fernández-Somoano, Ana; López, María José; Lertxundi, Aitana; Castilla, Ane Miren; Espada, Mercedes; Tardón, Adonina; Ballester, Ferran; Santa-Marina, Loreto

2016-02-01

Second-hand smoke exposure (SHS) in children remains as a major pollution problem, with important consequences for children's health. This study aimed to identify the sources of exposure to SHS among 4-year-old children, comparing self-reports to a urinary biomarker of exposure, and characterize the most important variables related to SHS exposure in this population. 4-year-old children's exposure to SHS was assessed by a parental-reported questionnaire and by urinary cotinine (UC) measurements in 1757 participants from 4 different areas of the Spanish INMA (INfancia y Medio Ambiente - Environment and Childhood) Project. The questionnaire about SHS included information about smoking habits at home by household members, and about exposure to SHS in other places including other homes, bars, restaurants or transportation. The association between quantified UC levels (>4ng/ml) and sociodemographic variables and the different sources of SHS exposure was examined using logistic regression. Based on parental reports, 21.6% of the children were exposed to SHS at home and 47.1% elsewhere; making a total 55.9% of the children exposed to SHS. In addition, 28.2% of the children whose parents reported being not regularly exposed to SHS had quantified UC values. Children from younger mothers (<34 vs. ≥39.4 y) had a higher odds of exposure to SHS [OR (95% CI): 2.28 (1.70-3.05) per year], as well as from families with a lower educational level [OR secondary: 2.12 (1.69-2.65); primary or less: 2.91 (2.19-3.88)]. The odds of quantifiable UC in children dropped after the smoking ban in public places [OR=0.59 (0.42-0.83)]. Regarding the sources of SHS exposure we observed that quantifiable UC odds was increased in children whose parents smoked at home in their presence [OR mother occasionally: 13.39 (7.03-25.50); mother often: 18.48 (8.40-40.66); father occasionally: 10.98 (6.52-18.49); father often: 11.50 (5.96-22.20)] or in children attending other confined places, mainly other

MAX phase – Alumina composites via exchange reaction in the M{sub n+1}AlC{sub n} systems (M=Ti, V, Cr, Nb, or Ta)

Energy Technology Data Exchange (ETDEWEB)

Cuskelly, Dylan T., E-mail: Dylan.cuskelly@uon.edu.au; Kisi, Erich H.; Sugo, Heber O.

2016-01-15

MAX phases have been produced for the first time via an exchange reaction between the M-element oxide and Al leading to an M–Al–C–Al{sub 2}O{sub 3} composite in the V–Al–C, Cr–Al–C, Nb–Al–C and Ta–Al–C systems in addition to the previously known Ti–Al–C system. The reduction reaction was first investigated by forming the binary M–X carbide and then proven to be generic across all M–Al–C systems with the production of the M{sub 2}AlC phase in each case. The work was extended to the other M{sub 3}AlC{sub 2} and M{sub 4}AlC{sub 3} phases in the respective systems, and was successful in 4 of the 5 cases with moderate yield. - Graphical abstract: A range of M{sub n+1}AX{sub n} phases (M-octahedra with X centres and A layers) were synthesised directly from the M oxide via exchange reactions for the 5 M-elements shown. - Highlights: • Ten M{sub n+1}AlC{sub n} phases were produced from M-oxides via a single step exchange reaction. • Eight of these MAX phases had not been produced via this method before. • Al was found to be a suitable reducing agent in all cases. • The process was also discovered to work under SHS and MASHS conditions.

Clear Skies and Grey Areas: Flight Attendants’ Secondhand Smoke Exposure and Attitudes toward Smoke-Free Policy 25 Years since Smoking was Banned on Airplanes

Directory of Open Access Journals (Sweden)

Frances A. Stillman

2015-06-01

Full Text Available Our objective was to provide descriptive data on flight attendant secondhand smoke (SHS exposure in the work environment, and to examine attitudes toward SHS exposure, personal health, and smoke-free policy in the workplace and public places. Flight attendants completed a web-based survey of self-reported SHS exposure and air quality in the work environment. We assessed the frequency and duration of SHS exposure in distinct areas of the workplace, attitudes toward SHS exposure and its health effects, and attitudes toward smoke-free policy in the workplace as well as general public places. A total of 723 flight attendants participated in the survey, and 591 responded to all survey questions. The mean level of exposure per flight attendant over the past month was 249 min. The majority of participants reported being exposed to SHS always/often in outdoor areas of an airport (57.7%. Participants who worked before the in-flight smoking ban (n = 240 were more likely to support further smoking policies in airports compared to participants who were employed after the ban (n = 346 (76.7% versus 60.4%, p-value < 0.01. Flight attendants are still being exposed to SHS in the workplace, sometimes at concerning levels during the non-flight portions of their travel. Flight attendants favor smoke-free policies and want to see further restrictions in airports and public places.

A Comparison of Survey Measures and Biomarkers of Secondhand Tobacco Smoke Exposure among Nonsmokers.

Science.gov (United States)

Okoli, Chizimuzo

2016-01-01

Secondhand tobacco smoke (SHS) exposure causes several adverse physical health outcomes. Conceptual differences in survey measures of 'psychosocial' (SHS exposure from smokers in an individual's life) and 'physical' (environments where an individual is exposed to SHS) SHS exposure exist. Few studies have examined the association between psychosocial and physical SHS exposures measures in comparison to biomarkers of SHS exposure. A secondary analysis of cross-sectional data was examined among a convenience sample of 20 adults. Data included survey items on SHS exposure and hair nicotine and saliva cotinine levels. Spearman analysis was used to assess correlations among variables. Medium and strong correlations were found among SHS exposure measures with the exception of saliva cotinine levels. Strong correlations were found among and between psychosocial and physical SHS exposure measures. Hair nicotine levels had medium strength associations with only perceived frequency of SHS exposure. As psychosocial measures of exposure were associated with biomarkers, such measures (particularly perceived frequency of SHS exposure) should be added to surveys in addition to physical SHS exposure measures to enhance accuracy of SHS measurement. Future explorations with robust sample sizes should further examine the strength of relationship between psychosocial and physical SHS exposure measures. © 2015 Wiley Periodicals, Inc.

Secondhand smoke exposure at home among middle and high school students in the United States - does the type of tobacco product matter?

Science.gov (United States)

Fischer, Florian; Kraemer, Alexander

2017-01-19

A decline in the prevalence of secondhand smoke (SHS) exposure has been observed in the United States of America (USA) during the past few decades. Nevertheless, nearly half of non-smoking students are still exposed to SHS. This paper aims to describe the factors associated with SHS exposure stratified by type of exposure (overall, cigarettes and electronic cigarettes). The analysis is based on secondary data taken from the National Youth Tobacco Survey 2014. Overall, 22,007 middle and high school students from the USA are included in the sample. Descriptive and bivariate statistics as well as binary logistic regression models were performed. Overall, 44.5% (n=9,798) of the study participants declared themselves to be exposed to SHS, 29.1% (n=6,394) declared to be exposed to SHS caused by cigarette smoke and 9.4% (n=2,067) claimed that a person who lives with them uses electronic cigarettes. There is a considerable overlap between the two types of SHS exposure, because 74.9% (n=1,548) of students declaring that a person within their household uses electronic cigarettes also declare a person in the household smoking cigarettes. The strengths of association between independent variables and SHS exposure differs by type of exposure and also by smoking status of respondents. Although only small differences are obvious in the factors associated with SHS exposure stratified by the type of tobacco product, there are still some variations which should be considered in policy making to allow for a targeted approach in prevention campaigns or legislation.

Relationship among reaction rate, release rate and efficiency of nanomachine-based targeted drug delivery.

Science.gov (United States)

Zhao, Qingying; Li, Min; Luo, Jun

2017-12-04

In nanomachine applications towards targeted drug delivery, drug molecules released by nanomachines propagate and chemically react with tumor cells in aqueous environment. If the nanomachines release drug molecules faster than the tumor cells react, it will result in loss and waste of drug molecules. It is a potential issue associated with the relationship among reaction rate, release rate and efficiency. This paper aims to investigate the relationship among reaction rate, release rate and efficiency based on two drug reception models. We expect to pave a way for designing a control method of drug release. We adopted two analytical methods that one is drug reception process based on collision with tumors and another is based on Michaelis Menten enzymatic kinetics. To evaluate the analytical formulations, we used the well-known simulation framework N3Sim to establish simulations. The analytical results of the relationship among reaction rate, release rate and efficiency is obtained, which match well with the numerical simulation results in a 3-D environment. Based upon two drug reception models, the results of this paper would be beneficial for designing a control method of nanomahine-based drug release.

Use of chemistry software to teach and assess model-based reaction and equation knowledge

Directory of Open Access Journals (Sweden)

Kevin Pyatt

2014-12-01

Full Text Available This study investigated the challenges students face when learning chemical reactions in a first-year chemistry course and the effectiveness of a curriculum and software implementation that was used to teach and assess student understanding of chemical reactions and equations. This study took place over a two year period in a public suburban high-school, in southwestern USA. Two advanced placement (AP chemistry classes participated, referred to here as study group A (year 1, N = 14; and study group B (year 2, N = 21. The curriculum for a first-year chemistry course (group A was revised to include instruction on reaction-types. The second year of the study involved the creation and implementation of a software solution which promoted mastery learning of reaction-types. Students in both groups benefited from the reaction-type curriculum and achieved proficiency in chemical reactions and equations.  The findings suggest there was an added learning benefit to using the reaction-type software solution. This study also found that reaction knowledge was a moderate to strong predictor of chemistry achievement. Based on regression analysis, reaction knowledge significantly predicted chemistry achievement for both groups.

A comparison of approximation techniques for variance-based sensitivity analysis of biochemical reaction systems

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Goutsias John

2010-05-01

Full Text Available Abstract Background Sensitivity analysis is an indispensable tool for the analysis of complex systems. In a recent paper, we have introduced a thermodynamically consistent variance-based sensitivity analysis approach for studying the robustness and fragility properties of biochemical reaction systems under uncertainty in the standard chemical potentials of the activated complexes of the reactions and the standard chemical potentials of the molecular species. In that approach, key sensitivity indices were estimated by Monte Carlo sampling, which is computationally very demanding and impractical for large biochemical reaction systems. Computationally efficient algorithms are needed to make variance-based sensitivity analysis applicable to realistic cellular networks, modeled by biochemical reaction systems that consist of a large number of reactions and molecular species. Results We present four techniques, derivative approximation (DA, polynomial approximation (PA, Gauss-Hermite integration (GHI, and orthonormal Hermite approximation (OHA, for analytically approximating the variance-based sensitivity indices associated with a biochemical reaction system. By using a well-known model of the mitogen-activated protein kinase signaling cascade as a case study, we numerically compare the approximation quality of these techniques against traditional Monte Carlo sampling. Our results indicate that, although DA is computationally the most attractive technique, special care should be exercised when using it for sensitivity analysis, since it may only be accurate at low levels of uncertainty. On the other hand, PA, GHI, and OHA are computationally more demanding than DA but can work well at high levels of uncertainty. GHI results in a slightly better accuracy than PA, but it is more difficult to implement. OHA produces the most accurate approximation results and can be implemented in a straightforward manner. It turns out that the computational cost of the

Fast and quantitative differentiation of single-base mismatched DNA by initial reaction rate of catalytic hairpin assembly.

Science.gov (United States)

Li, Chenxi; Li, Yixin; Xu, Xiao; Wang, Xinyi; Chen, Yang; Yang, Xiaoda; Liu, Feng; Li, Na

2014-10-15

The widely used catalytic hairpin assembly (CHA) amplification strategy generally needs several hours to accomplish one measurement based on the prevailingly used maximum intensity detection mode, making it less practical for assays where high throughput or speed is desired. To make the best use of the kinetic specificity of toehold domain for circuit reaction initiation, we developed a mathematical model and proposed an initial reaction rate detection mode to quantitatively differentiate the single-base mismatch. Using the kinetic mode, assay time can be reduced substantially to 10 min for one measurement with the comparable sensitivity and single-base mismatch differentiating ability as were obtained by the maximum intensity detection mode. This initial reaction rate based approach not only provided a fast and quantitative differentiation of single-base mismatch, but also helped in-depth understanding of the CHA system, which will be beneficial to the design of highly sensitive and specific toehold-mediated hybridization reactions. Copyright © 2014 Elsevier B.V. All rights reserved.

Biosensing strategies based on enzymatic reactions and nanoparticles.

Science.gov (United States)

Díez-Buitrago, Beatriz; Briz, Nerea; Liz-Marzán, Luis M; Pavlov, Valeri

2018-04-16

Enzymes are pivotal elements in bioanalysis due to their specificity and extremely high catalytic activity. The sensitivity of bioanalytical assays depends mainly on the capacity of an observer to detect the product(s) of a biocatalytic reaction. Both natural and artificial compounds have been traditionally used to evaluate enzymatic activities. The drawbacks of chromogenic and fluorogenic organic enzymatic substrates are their high cost and low stability, resulting in high background signals. We review here state of the art assays in the detection of enzymatic activities using recent advances in nanoscience. Novel methods based on the use of nanoparticles lead to increased sensitivity and decreased costs for bioanalysis based on enzymes as recognition elements and signal amplifiers in Enzyme-Linked Immunosorbent Assays (ELISA). Novel approaches toward the detection of enzymatic activities are based on biocatalytic synthesis, modulation, etching, and aggregation of nanoparticles under physiological conditions.

Chemical Reactions Catalyzed by Metalloporphyrin-Based Metal-Organic Frameworks

Directory of Open Access Journals (Sweden)

Kelly Aparecida Dias de Freitas Castro

2013-06-01

Full Text Available The synthetic versatility and the potential application of metalloporphyrins (MP in different fields have aroused researchers’ interest in studying these complexes, in an attempt to mimic biological systems such as cytochrome P-450. Over the last 40 years, synthetic MPs have been mainly used as catalysts for homogeneous or heterogeneous chemical reactions. To employ them in heterogeneous catalysis, chemists have prepared new MP-based solids by immobilizing MP onto rigid inorganic supports, a strategy that affords hybrid inorganic-organic materials. More recently, materials obtained by supramolecular assembly processes and containing MPs as building blocks have been applied in a variety of areas, like gas storage, photonic devices, separation, molecular sensing, magnets, and heterogeneous catalysis, among others. These coordination polymers, known as metal-organic frameworks (MOFs, contain organic ligands or complexes connected by metal ions or clusters, which give rise to a 1-, 2- or 3-D network. These kinds of materials presents large surface areas, Brønsted or redox sites, and high porosity, all of which are desirable features in catalysts with potential use in heterogeneous phases. Building MOFs based on MP is a good way to obtain solid catalysts that offer the advantages of bioinspired systems and zeolitic materials. In this mini review, we will adopt a historical approach to present the most relevant MP-based MOFs applicable to catalytic reactions such as oxidation, reduction, insertion of functional groups, and exchange of organic functions.

Nuclear reaction inputs based on effective interactions

Energy Technology Data Exchange (ETDEWEB)

Hilaire, S.; Peru, S.; Dubray, N.; Dupuis, M.; Bauge, E. [CEA, DAM, DIF, Arpajon (France); Goriely, S. [Universite Libre de Bruxelles, Institut d' Astronomie et d' Astrophysique, CP-226, Brussels (Belgium)

2016-11-15

Extensive nuclear structure studies have been performed for decades using effective interactions as sole input. They have shown a remarkable ability to describe rather accurately many types of nuclear properties. In the early 2000 s, a major effort has been engaged to produce nuclear reaction input data out of the Gogny interaction, in order to challenge its quality also with respect to nuclear reaction observables. The status of this project, well advanced today thanks to the use of modern computers as well as modern nuclear reaction codes, is reviewed and future developments are discussed. (orig.)

A reaction-based fluorescent sensor for detection of cyanide in aqueous media

Energy Technology Data Exchange (ETDEWEB)

Wang, Shan-Teng; Sie, Yi-Wun [Department of Chemistry, National Changhua University of Education, Changhua 50058, Taiwan (China); Wan, Chin-Feng [School of Applied Chemistry, Chung Shan Medical University, Taichung City 40201, Taiwan (China); Wu, An-Tai, E-mail: antai@cc.ncue.edu.tw [Department of Chemistry, National Changhua University of Education, Changhua 50058, Taiwan (China)

2016-05-15

A simple boronic acid derivative was utilized as a reaction-based receptor for CN{sup −} in aqueous solution. The receptor showed a selective and sensitive response to CN{sup −} over other various anions via nucleophilic addition of CN{sup −} to the imine moiety of the boronic-based receptor.

Self-propagating high-temperature synthesis of La(Sr)Ga(Mg)O{sub 3-{delta}} for electrolyte of solid oxide fuel cells

Energy Technology Data Exchange (ETDEWEB)

Ishikawa, Hiroyuki [Center for Advanced Research of Energy Conversion Materials, Hokkaido University, Sapporo 060-8628 (Japan); Enoki, Makiko [Department of Applied Chemistry, Faculty of Engineering, Kyusyu University, Fukuoka 812-8581 (Japan); Ishihara, Tatsumi [Department of Applied Chemistry, Faculty of Engineering, Kyusyu University, Fukuoka 812-8581 (Japan); Akiyama, Tomohiro [Center for Advanced Research of Energy Conversion Materials, Hokkaido University, Sapporo 060-8628 (Japan)]. E-mail: takiyama@eng.hokudai.ac.jp

2007-03-14

This paper describes self-propagating high-temperature synthesis (SHS) of an electrolyte for solid oxide fuel (SOFC), in comparison to a conventional solid-state reaction method (SRM). Doped-lanthanum gallate: La{sub 0.9}Sr{sub 0.1}Ga{sub 0.8}Mg{sub 0.2}O{sub 3-{delta}} (LSGM9182) and LSGM9173 as the SOFC electrolyte, was prepared by the SHS and sintered at different temperatures, for measuring the electrical conductivity of the sintered LSGM and the power generating performance at 1073 K, in comparison to the SRM. In the SHS, the LSGM powders with smaller size were obtained and easily sintered at the 100 K-lower temperature, 1673 K, than in the SRM. Most significantly, the electrical conductivity of the sintered LSGM9182 was as high as 0.11 S cm{sup -1} and its maximum power density was a value of 245 mW cm{sup -2} in the cell configuration of Ni/LSGM9182 (0.501 mm in thickness)/Sm{sub 0.5}Sr{sub 0.5}CoO{sub 3}. The conclusion was that the proposed SHS-sintering method with many benefits of minimizing the energy requirement and the processing time in the production, easing temperature restriction for the sintering, and improving the electrolyte performance up to a conventional level is practicable for producing the LSGM-electrolyte of SOFC at an intermediate-temperature application.

Self-propagating high-temperature synthesis of La(Sr)Ga(Mg)O3-δ for electrolyte of solid oxide fuel cells

International Nuclear Information System (INIS)

Ishikawa, Hiroyuki; Enoki, Makiko; Ishihara, Tatsumi; Akiyama, Tomohiro

2007-01-01

This paper describes self-propagating high-temperature synthesis (SHS) of an electrolyte for solid oxide fuel (SOFC), in comparison to a conventional solid-state reaction method (SRM). Doped-lanthanum gallate: La 0.9 Sr 0.1 Ga 0.8 Mg 0.2 O 3-δ (LSGM9182) and LSGM9173 as the SOFC electrolyte, was prepared by the SHS and sintered at different temperatures, for measuring the electrical conductivity of the sintered LSGM and the power generating performance at 1073 K, in comparison to the SRM. In the SHS, the LSGM powders with smaller size were obtained and easily sintered at the 100 K-lower temperature, 1673 K, than in the SRM. Most significantly, the electrical conductivity of the sintered LSGM9182 was as high as 0.11 S cm -1 and its maximum power density was a value of 245 mW cm -2 in the cell configuration of Ni/LSGM9182 (0.501 mm in thickness)/Sm 0.5 Sr 0.5 CoO 3 . The conclusion was that the proposed SHS-sintering method with many benefits of minimizing the energy requirement and the processing time in the production, easing temperature restriction for the sintering, and improving the electrolyte performance up to a conventional level is practicable for producing the LSGM-electrolyte of SOFC at an intermediate-temperature application

Male smoker and non-smoker responses to television advertisements on the harms of secondhand smoke in China, India and Russia.

Science.gov (United States)

Murukutla, Nandita; Bayly, Megan; Mullin, Sandra; Cotter, Trish; Wakefield, Melanie

2015-02-01

Mass media campaigns can play an important role in strengthening support for smoke-free policies and reducing exposure to secondhand smoke (SHS). Identifying anti-SHS advertisements that are effective in diverse cultural contexts may allow for resource sharing in low- and middle-income countries. A convenience sample of 481 male cigarette smokers and non-smokers in three high tobacco burden and culturally dissimilar countries (India, China and Russia) viewed and rated five anti-SHS ads. Multivariate logistic regression analyses were conducted for 'Message Acceptance', 'Negative Emotion', 'Perceived Effectiveness' and 'Behavioral Intentions'. Smokers and non-smokers in all countries consistently rated the strong graphic, health harm ads as the most effective, and the 'informational' ad as the least effective overall: the graphic ad 'Baby Alive' was at least 1.8 times more likely than the informational ad 'Smoke-free works' to receive positive ratings on all four outcomes (all P messages about SHS exposure have the greatest universal appeal and are the most effective in motivating changes in behavioral intentions. Similarity in reactions between smokers and non-smokers, and across countries, suggests that resource sharing and the use of a single graphic ad targeted at smokers and non-smokers would be cost-efficient strategies. © The Author 2014. Published by Oxford University Press. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Exploring the Reaction Pathways of Bioglycerol Hydrodeoxygenation to Propene over Molybdena-Based Catalysts.

Science.gov (United States)

Zacharopoulou, Vasiliki; Vasiliadou, Efterpi S; Lemonidou, Angeliki A

2018-01-10

The one-step reaction of glycerol with hydrogen to form propene selectively is a particularly challenging catalytic pathway that has not yet been explored thoroughly. Molybdena-based catalysts are active and selective to C-O bond scission; propene is the only product in the gas phase under the standard reaction conditions, and further hydrogenation to propane is impeded. Within this context, this work focuses on the exploration of the reaction pathways and the investigation of various parameters that affect the catalytic performance, such as the role of hydrogen on the product distribution and the effect of the catalyst pretreatment step. Under a hydrogen atmosphere, propene is produced primarily via 2-propenol, whereas under an inert atmosphere propanal and glycerol dissociation products are formed mainly. The reaction most likely proceeds through a reverse Mars-van Krevelen mechanism as partially reduced Mo species drive the reaction to the formation of the desired product. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Maps of Fe-Al phases formation kinetics parameters during isothermal sintering

Energy Technology Data Exchange (ETDEWEB)

Pochec, Ewelina, E-mail: epochec@wat.edu.pl [Department of Advanced Materials and Technology, Military University of Technology (Poland); Jozwiak, Stanislaw; Karczewski, Krzysztof; Bojar, Zbigniew [Department of Advanced Materials and Technology, Military University of Technology (Poland)

2012-10-10

Highlights: Black-Right-Pointing-Pointer The sintering temperature and compaction pressure have a strong influence on the sinters structure. Black-Right-Pointing-Pointer The measurements confirmed the presence of the high-aluminium phases from Fe-Al equilibrium system in tested sinters. Black-Right-Pointing-Pointer The kinetics of Fe-Al phase formation can be described by Johnson-Mehl-Avrami modelling. - Abstract: The influence of technological parameters (compaction pressure and sintering temperature) on Fe-Al phase formation was investigated. The kinetics of phase transformation preceding and during an SHS reaction was studied in isothermal conditions by DSC using the JMA (Johnson-Mehl-Avrami) model. This model allowed us to determine basic kinetic parameters, including the Avrami exponent, which characterises the rate and manner of particular phase nucleation. The activation energy (E{sub a}) of particular phase formation was determined by the Kissinger method. XRD analysis and SEM observations of sintered material showed that not only Fe{sub 2}Al{sub 5} phase and low-aluminium solid solution in iron but also aluminium-rich FeAl{sub 2} and FeAl{sub 3} phases are formed during the sintering of an FeAl50 elementary powder mixture in isothermal conditions with an SHS reaction. The above conclusions were confirmed by iron-based solid solution lattice parameter studies and microhardness measurements.

Exposure to secondhand smoke in the home and mental health in children: a population-based study.

Science.gov (United States)

Padrón, Alicia; Galán, Iñaki; García-Esquinas, Esther; Fernández, Esteve; Ballbè, Montse; Rodríguez-Artalejo, Fernando

2016-05-01

To examine the association between exposure to secondhand smoke (SHS) in the home and mental health among children. Cross-sectional study of 2357 children representative of the Spanish population aged 4-12 years in 2011-2012. Duration of SHS exposure in children was reported by parents. Probable mental disorder was defined as a score>90th centile in the parental version of the Strengths and Difficulties Questionnaire (SDQ). Statistical analysis was performed with logistic regression and adjusted for sociodemographic variables, lifestyle, neighbourhood environment and family characteristics, including parental mental health. Among study participants, 6.9% (95% CI 5.7% to 8.0%) were exposed to SHS in the home for exposureexposure≥1 h/day (p for linear trend=0.002). The corresponding ORs for attention-deficit and hyperactivity disorder (ADHD) were 2.18 (95% CI 1.30 to 3.64) for exposure and 3.14 (95% CI 1.63 to 6.04) for ≥1 h/day exposure (p for linear trendexposure in the home during ≥1 h/day is associated with a higher frequency of mental disorder. This association was mostly due to the impact of SHS on ADHD. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Web-Based Search and Plot System for Nuclear Reaction Data

International Nuclear Information System (INIS)

Otuka, N.; Nakagawa, T.; Fukahori, T.; Katakura, J.; Aikawa, M.; Suda, T.; Naito, K.; Korennov, S.; Arai, K.; Noto, H.; Ohnishi, A.; Kato, K.

2005-01-01

A web-based search and plot system for nuclear reaction data has been developed, covering experimental data in EXFOR format and evaluated data in ENDF format. The system is implemented for Linux OS, with Perl and MySQL used for CGI scripts and the database manager, respectively. Two prototypes for experimental and evaluated data are presented

Metal mixtures in urban and rural populations in the US: The Multi-Ethnic Study of Atherosclerosis and the Strong Heart Study

Energy Technology Data Exchange (ETDEWEB)

Pang, Yuanjie, E-mail: yuanjie.p@gmail.com [Departments of Epidemiology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD 21205 (United States); Peng, Roger D., E-mail: rdpeng@jhu.edu [Departments of Biostatistics, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD 21205 (United States); Jones, Miranda R., E-mail: mjone132@jhu.edu [Departments of Epidemiology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD 21205 (United States); Francesconi, Kevin A., E-mail: kevin.francesconi@uni-graz.at [Institute of Chemistry -Analytical Chemistry, University of Graz, Graz 8010 (Austria); Goessler, Walter, E-mail: walter.goessler@uni-graz.at [Institute of Chemistry -Analytical Chemistry, University of Graz, Graz 8010 (Austria); Howard, Barbara V., E-mail: Barbara.V.Howard@Medstar.net [MedStar Health Research Institute, Hyattsville, MD 20782 (United States); Georgetown-Howard Universities Center for Clinical and Translational Science, Washington, DC 20057 (United States); Umans, Jason G., E-mail: jason.umans@gmail.com [MedStar Health Research Institute, Hyattsville, MD 20782 (United States); Georgetown-Howard Universities Center for Clinical and Translational Science, Washington, DC 20057 (United States); Best, Lyle G., E-mail: lbest@restel.com [Missouri Breaks Industries Research, Inc., Timber Lake, SD 57656 (United States); Guallar, Eliseo, E-mail: eguallar@jhu.edu [Departments of Epidemiology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD 21205 (United States); Welch Center for Prevention, Epidemiology and Clinical Research, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD 21205 (United States); Department of Medicine, Johns Hopkins School of Medicine, Baltimore, MD 21205 (United States); and others

2016-05-15

Background: Natural and anthropogenic sources of metal exposure differ for urban and rural residents. We searched to identify patterns of metal mixtures which could suggest common environmental sources and/or metabolic pathways of different urinary metals, and compared metal-mixtures in two population-based studies from urban/sub-urban and rural/town areas in the US: the Multi-Ethnic Study of Atherosclerosis (MESA) and the Strong Heart Study (SHS). Methods: We studied a random sample of 308 White, Black, Chinese-American, and Hispanic participants in MESA (2000–2002) and 277 American Indian participants in SHS (1998–2003). We used principal component analysis (PCA), cluster analysis (CA), and linear discriminant analysis (LDA) to evaluate nine urinary metals (antimony [Sb], arsenic [As], cadmium [Cd], lead [Pb], molybdenum [Mo], selenium [Se], tungsten [W], uranium [U] and zinc [Zn]). For arsenic, we used the sum of inorganic and methylated species (∑As). Results: All nine urinary metals were higher in SHS compared to MESA participants. PCA and CA revealed the same patterns in SHS, suggesting 4 distinct principal components (PC) or clusters (∑As-U-W, Pb-Sb, Cd-Zn, Mo-Se). In MESA, CA showed 2 large clusters (∑As-Mo-Sb-U-W, Cd-Pb-Se-Zn), while PCA showed 4 PCs (Sb-U-W, Pb-Se-Zn, Cd-Mo, ∑As). LDA indicated that ∑As, U, W, and Zn were the most discriminant variables distinguishing MESA and SHS participants. Conclusions: In SHS, the ∑As-U-W cluster and PC might reflect groundwater contamination in rural areas, and the Cd-Zn cluster and PC could reflect common sources from meat products or metabolic interactions. Among the metals assayed, ∑As, U, W and Zn differed the most between MESA and SHS, possibly reflecting disproportionate exposure from drinking water and perhaps food in rural Native communities compared to urban communities around the US. - Highlights: • We identified and compared environmental sources of urinary metals in MESA and SHS. �

Metal mixtures in urban and rural populations in the US: The Multi-Ethnic Study of Atherosclerosis and the Strong Heart Study

International Nuclear Information System (INIS)

Pang, Yuanjie; Peng, Roger D.; Jones, Miranda R.; Francesconi, Kevin A.; Goessler, Walter; Howard, Barbara V.; Umans, Jason G.; Best, Lyle G.; Guallar, Eliseo

2016-01-01

Background: Natural and anthropogenic sources of metal exposure differ for urban and rural residents. We searched to identify patterns of metal mixtures which could suggest common environmental sources and/or metabolic pathways of different urinary metals, and compared metal-mixtures in two population-based studies from urban/sub-urban and rural/town areas in the US: the Multi-Ethnic Study of Atherosclerosis (MESA) and the Strong Heart Study (SHS). Methods: We studied a random sample of 308 White, Black, Chinese-American, and Hispanic participants in MESA (2000–2002) and 277 American Indian participants in SHS (1998–2003). We used principal component analysis (PCA), cluster analysis (CA), and linear discriminant analysis (LDA) to evaluate nine urinary metals (antimony [Sb], arsenic [As], cadmium [Cd], lead [Pb], molybdenum [Mo], selenium [Se], tungsten [W], uranium [U] and zinc [Zn]). For arsenic, we used the sum of inorganic and methylated species (∑As). Results: All nine urinary metals were higher in SHS compared to MESA participants. PCA and CA revealed the same patterns in SHS, suggesting 4 distinct principal components (PC) or clusters (∑As-U-W, Pb-Sb, Cd-Zn, Mo-Se). In MESA, CA showed 2 large clusters (∑As-Mo-Sb-U-W, Cd-Pb-Se-Zn), while PCA showed 4 PCs (Sb-U-W, Pb-Se-Zn, Cd-Mo, ∑As). LDA indicated that ∑As, U, W, and Zn were the most discriminant variables distinguishing MESA and SHS participants. Conclusions: In SHS, the ∑As-U-W cluster and PC might reflect groundwater contamination in rural areas, and the Cd-Zn cluster and PC could reflect common sources from meat products or metabolic interactions. Among the metals assayed, ∑As, U, W and Zn differed the most between MESA and SHS, possibly reflecting disproportionate exposure from drinking water and perhaps food in rural Native communities compared to urban communities around the US. - Highlights: • We identified and compared environmental sources of urinary metals in MESA and SHS. �

Differences between Drug-Induced and Contrast Media-Induced Adverse Reactions Based on Spontaneously Reported Adverse Drug Reactions.

Science.gov (United States)

Ryu, JiHyeon; Lee, HeeYoung; Suh, JinUk; Yang, MyungSuk; Kang, WonKu; Kim, EunYoung

2015-01-01

We analyzed differences between spontaneously reported drug-induced (not including contrast media) and contrast media-induced adverse reactions. Adverse drug reactions reported by an in-hospital pharmacovigilance center (St. Mary's teaching hospital, Daejeon, Korea) from 2010-2012 were classified as drug-induced or contrast media-induced. Clinical patterns, frequency, causality, severity, Schumock and Thornton's preventability, and type A/B reactions were recorded. The trends among causality tools measuring drug and contrast-induced adverse reactions were analyzed. Of 1,335 reports, 636 drug-induced and contrast media-induced adverse reactions were identified. The prevalence of spontaneously reported adverse drug reaction-related admissions revealed a suspected adverse drug reaction-reporting rate of 20.9/100,000 (inpatient, 0.021%) and 3.9/100,000 (outpatients, 0.004%). The most common adverse drug reaction-associated drug classes included nervous system agents and anti-infectives. Dermatological and gastrointestinal adverse drug reactions were most frequently and similarly reported between drug and contrast media-induced adverse reactions. Compared to contrast media-induced adverse reactions, drug-induced adverse reactions were milder, more likely to be preventable (9.8% vs. 1.1%, p contrast media-induced adverse reactions (56.6%, p = 0.066). Causality patterns differed between the two adverse reaction classes. The World Health Organization-Uppsala Monitoring Centre causality evaluation and Naranjo algorithm results significantly differed from those of the Korean algorithm version II (p contrast media-induced adverse reactions. The World Health Organization-Uppsala Monitoring Centre and Naranjo algorithm causality evaluation afforded similar results.

Pulmonary effects of active smoking and secondhand smoke exposure among adolescent students in Juárez, Mexico.

Science.gov (United States)

Bird, Yelena; Staines-Orozco, Hugo

2016-01-01

increased respiratory symptoms and reduction of pulmonary function test values. Public health initiatives that aim to prevent smoking initiation, assist in cessation, and lessen SHS exposure of adolescents need to be school-based and employed as early as middle school.

Boron-Based Catalysts for C-C Bond-Formation Reactions.

Science.gov (United States)

Rao, Bin; Kinjo, Rei

2018-05-02

Because the construction of the C-C bond is one of the most significant reactions in organic chemistry, the development of an efficient strategy has attracted much attention throughout the synthetic community. Among various protocols to form C-C bonds, organoboron compounds are not just limited to stoichiometric reagents, but have also made great achievements as catalysts because of the easy modification of the electronic and steric impacts on the boron center. This review presents recent developments of boron-based catalysts applied in the field of C-C bond-formation reactions, which are classified into four kinds on the basis of the type of boron catalyst: 1) highly Lewis acidic borane, B(C 6 F 5 ) 3 ; 2) organoboron acids, RB(OH) 2 , and their ester derivatives; 3) borenium ions, (R 2 BL)X; and 4) other miscellaneous kinds. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Gas-phase ion/ion reactions of peptides and proteins: acid/base, redox, and covalent chemistries.

Science.gov (United States)

Prentice, Boone M; McLuckey, Scott A

2013-02-01

Gas-phase ion/ion reactions are emerging as useful and flexible means for the manipulation and characterization of peptide and protein biopolymers. Acid/base-like chemical reactions (i.e., proton transfer reactions) and reduction/oxidation (redox) reactions (i.e., electron transfer reactions) represent relatively mature classes of gas-phase chemical reactions. Even so, especially in regards to redox chemistry, the widespread utility of these two types of chemistries is undergoing rapid growth and development. Additionally, a relatively new class of gas-phase ion/ion transformations is emerging which involves the selective formation of functional-group-specific covalent bonds. This feature details our current work and perspective on the developments and current capabilities of these three areas of ion/ion chemistry with an eye towards possible future directions of the field.

Photonuclear reactions in astrophysical p-process: Theoretical calculations and experiment simulation based on ELI-NP

Science.gov (United States)

Xu, Yi; Luo, Wen; Balabanski, Dimiter; Goriely, Stephane; Matei, Catalin; Tesileanu, Ovidiu

2017-09-01

The astrophysical p-process is an important way of nucleosynthesis to produce the stable and proton-rich nuclei beyond Fe which can not be reached by the s- and r-processes. In the present study, the astrophysical reaction rates of (γ,n), (γ,p), and (γ,α) reactions are computed within the modern reaction code TALYS for about 3000 stable and proton-rich nuclei with 12 Infrastructure-Nuclear Physics (ELI-NP) facility is being developed, which will provide the great opportunity to experimentally study the photonuclear reactions in p-process. Simulations of the experimental setup for the measurements of the photonuclear reactions 96Ru(γ,p) and 96Ru(γ,α) are performed. It is shown that the experiments of photonuclear reactions in p-process based on ELI-NP are quite promising.

Secondhand Smoke Exposure and Smoking Behavior Among Young Adult Bar Patrons

Science.gov (United States)

Kalkhoran, Sara; Neilands, Torsten B.

2013-01-01

Objectives. We described frequency of secondhand smoke (SHS) exposure among young adults patronizing bars and associations between SHS exposure, attitudes, and smoking behavior. Methods. We collected cross-sectional surveys from randomized time–location samples of bar patrons aged 18 to 26 years in San Diego, California, and Oklahoma City and Tulsa, Oklahoma, in 2010 to 2011. Multivariate logistic regression evaluated associations between SHS exposure, attitudes about dangers of SHS, susceptibility to smoking initiation among nonsmokers, and quit attempts among current smokers. Results. More than 80% of respondents reported past 7-day exposure to any SHS, and more than 70% reported exposure at a bar. Current smokers reported more SHS exposure in cars and their own homes than did nonsmokers. Among nonsmokers, SHS exposure was associated with susceptibility to initiation, but those who believed that SHS exposure is harmful were less susceptible. Belief that SHS is dangerous was associated with quit attempts among smokers. Conclusions. Smoke-free environments and education about the harms of SHS may decrease tobacco use among young adults who frequent bars, where they are heavily exposed to SHS. PMID:24028259

Tobacco smoke exposure in public places and workplaces after smoke-free policy implementation: a longitudinal analysis of smoker cohorts in Mexico and Uruguay

Science.gov (United States)

Thrasher, James F.; Nayeli Abad-Vivero, Erika; Sebrié, Ernesto M.; Barrientos-Gutierrez, Tonatiuh; Boado, Marcelo; Yong, Hua Hie; Arillo-Santillán, Edna; Bianco, Eduardo

2013-01-01

Objective: To determine the prevalence, correlates and changes in secondhand smoke (SHS) exposure over the period after comprehensive smoke-free policy implementation in two Latin American countries. Methods: Data were analysed from population-based representative samples of adult smokers and recent quitters from the 2008 and 2010 waves of the International Tobacco Control Policy Evaluation Survey in Mexico (n = 1766 and 1840, respectively) and Uruguay (n = 1379 and 1411, respectively). Prevalence of SHS exposure was estimated for regulated venues, and generalized estimating equations were used to determine correlates of SHS exposure. Results: Workplace SHS exposure in the last month was similar within and across countries (range: Mexico 20–25%; Uruguay 14–29%). At the most recent restaurant visit, SHS exposure was lower where comprehensive smoke-free policies were implemented (range: Uruguay 6–9%; Mexico City 5–7%) compared with Mexican cities with weaker policies, where exposure remained higher but decreased over time (32–17%). At the most recent bar visit, SHS exposure was common (range: Uruguay 8–36%; Mexico City 23–31%), although highest in jurisdictions with weaker policies (range in other Mexican cities: 74–86%). In Uruguay, males were more likely than females to be exposed to SHS across venues, as were younger compared with older smokers in Mexico. Conclusions: Comprehensive smoke-free policies are more effective than weaker policies, although compliance in Mexico and Uruguay is not as high as desired. PMID:23172895

Sheldon-Hall syndrome

Directory of Open Access Journals (Sweden)

Bamshad Michael J

2009-03-01

Full Text Available Abstract Sheldon-Hall syndrome (SHS is a rare multiple congenital contracture syndrome characterized by contractures of the distal joints of the limbs, triangular face, downslanting palpebral fissures, small mouth, and high arched palate. Epidemiological data for the prevalence of SHS are not available, but less than 100 cases have been reported in the literature. Other common clinical features of SHS include prominent nasolabial folds, high arched palate, attached earlobes, mild cervical webbing, short stature, severe camptodactyly, ulnar deviation, and vertical talus and/or talipes equinovarus. Typically, the contractures are most severe at birth and non-progressive. SHS is inherited in an autosomal dominant pattern but about half the cases are sporadic. Mutations in either MYH3, TNNI2, or TNNT3 have been found in about 50% of cases. These genes encode proteins of the contractile apparatus of fast twitch skeletal muscle fibers. The diagnosis of SHS is based on clinical criteria. Mutation analysis is useful to distinguish SHS from arthrogryposis syndromes with similar features (e.g. distal arthrogryposis 1 and Freeman-Sheldon syndrome. Prenatal diagnosis by ultrasonography is feasible at 18–24 weeks of gestation. If the family history is positive and the mutation is known in the family, prenatal molecular genetic diagnosis is possible. There is no specific therapy for SHS. However, patients benefit from early intervention with occupational and physical therapy, serial casting, and/or surgery. Life expectancy and cognitive abilities are normal.

Isotope effects for base-promoted, gas-phase proton transfer reactions

International Nuclear Information System (INIS)

Grabowski, J.J.; Cheng, Xueheng

1991-01-01

Proton transfer reactions are among the most basic, the most common and the most important of chemical transformations; despite their apparent simplicity, much is unknown about this most fundamental of all chemical processes. Active interest in understanding the underlying principles of organic proton transfer reactions continues because of efforts being made to develop the theory of elementary chemical processes, because of the resurgence of interest in mechanistic organic chemistry and because of the resurgence of interest in mechanistic organic chemistry processes, because of the resurgence of interest in mechanistic organic chemistry and because of the dynamic role played by proton transfers in biochemical transformations. As organic chemists, the authors have used the flowing afterglow technique to gain an appreciation of the fundamental issues involved in reaction mechanisms by examining such processes in a solvent-free environment under thermally-equilibrated (300 K) conditions. Recent characterization of the facile production of both acetate and the monoenolate anion from the interaction of hydroxide or fluoride with acetic acid reinforces the idea that much yet must be learned about proton transfers/proton abstractions in general. Earlier work by Riveros and co-workers on competitive H vs D abstraction from α-d 1 -toluenes and by Noest and Nibbering on competitive H vs D abstraction from α,α,α-d 3 -acetone, in combination with the acetic acid results, challenged the author's to assemble a comprehensive picture of the competitive nature of proton transfer reactions for anionic base-promoted processes

Liquid chromatography/tandem mass spectrometry method for quantitative estimation of solutol HS15 and its applications.

Science.gov (United States)

Bhaskar, V Vijaya; Middha, Anil; Srivastava, Pratima; Rajagopal, Sriram

2015-04-01

A rapid, sensitive and selective pseudoMRM (pMRM)-based method for the determination of solutol HS15 (SHS15) in rat plasma was developed using liquid chromatography/tandem mass spectrometry (LC-MS/MS). The most abundant ions corresponding to SHS15 free polyethyleneglycol (PEG) oligomers at m / z 481, 525, 569, 613, 657, 701, 745, 789, 833, 877, 921 and 965 were selected for pMRM in electrospray mode of ionization. Purity of the lipophilic and hydrophilic components of SHS15 was estimated using evaporative light scattering detector (ELSD). Plasma concentrations of SHS15 were measured after oral administration at 2.50 g/kg dose and intravenous administration at 1.00 g/kg dose in male Sprague Dawley rats. SHS15 has poor oral bioavailability of 13.74% in rats. Differences in pharmacokinetics of oligomers were studied. A novel proposal was conveyed to the scientific community, where formulation excipient could be analyzed as a qualifier in the analysis of new chemical entities (NCEs) to address the spiky plasma concentration profiles.

ReaDDy--a software for particle-based reaction-diffusion dynamics in crowded cellular environments.

Directory of Open Access Journals (Sweden)

Johannes Schöneberg

Full Text Available We introduce the software package ReaDDy for simulation of detailed spatiotemporal mechanisms of dynamical processes in the cell, based on reaction-diffusion dynamics with particle resolution. In contrast to other particle-based reaction kinetics programs, ReaDDy supports particle interaction potentials. This permits effects such as space exclusion, molecular crowding and aggregation to be modeled. The biomolecules simulated can be represented as a sphere, or as a more complex geometry such as a domain structure or polymer chain. ReaDDy bridges the gap between small-scale but highly detailed molecular dynamics or Brownian dynamics simulations and large-scale but little-detailed reaction kinetics simulations. ReaDDy has a modular design that enables the exchange of the computing core by efficient platform-specific implementations or dynamical models that are different from Brownian dynamics.

Direct containment heating experiments in Zion Nuclear Power Plant geometry using prototypic materials

International Nuclear Information System (INIS)

Binder, J.L.; McUmber, L.M.; Spencer, B.W.

1993-01-01

Direct Containment Heating (DCH) experiments have been completed which utilize prototypic core materials. The experiments reported on here are a continuation of the Integral Effects Testing (IET) DCH program. The experiments incorporated a 1/40 scale model of the Zion Nuclear Power Plant containment structures. The model included representations of the primary system volume, RPV lower head, cavity and instrument tunnel, and the lower containment structures. The experiments were steam driven. Iron-alumina thermite with chromium was used as a core melt stimulant in the earlier IET experiments. These earlier IET experiments at Argonne National Laboratory (ANL) and Sandia National Laboratories (SNL) provided useful data on the effect of scale on DCH phenomena; however, a significant question concerns the potential experiment distortions introduced by the use of non-prototypic iron/alumina thermite. Therefore, further testing with prototypic materials has been carried out at ANL. Three tests have been completed, DCH-U1A, U1B and U2. DCH-U1A and U1B employed an inerted containment atmosphere and are counterpart to the IET-1RR test with iron/alumina thermite. DCH-U2 employed nominally the same atmosphere composition of its counterpart iron/alumina test, IET-6. All tests, with prototypic material, have produced lower peak containment pressure rises; 45, 111 and 185 kPa in U1A, U1B and U2, compared to 150 and 250 kPa IET-1RR and 6. Hydrogen production, due to metal-steam reactions, was 33% larger in U1B and U2 compared to IET-1RR and IET-6. The pressurization efficiency was consistently lower for the corium tests compared to the IET tests

Non-allergic cutaneous reactions in airborne chemical sensitivity--a population based study.

Science.gov (United States)

Berg, Nikolaj Drimer; Linneberg, Allan; Thyssen, Jacob Pontoppidan; Dirksen, Asger; Elberling, Jesper

2011-06-01

Multiple chemical sensitivity (MCS) is characterised by adverse effects due to exposure to low levels of chemical substances. The aetiology is unknown, but chemical related respiratory symptoms have been found associated with positive patch test. The purpose of this study was to investigate the relationship between cutaneous reactions from patch testing and self-reported severity of chemical sensitivity to common airborne chemicals. A total of 3460 individuals participating in a general health examination, Health 2006, were patch tested with allergens from the European standard series and screened for chemical sensitivity with a standardised questionnaire dividing the participants into four severity groups of chemical sensitivity. Both allergic and non-allergic cutaneous reactions--defined as irritative, follicular, or doubtful allergic reactions--were analysed in relationship with severity of chemical sensitivity. Associations were controlled for the possible confounding effects of sex, age, asthma, eczema, atopic dermatitis, psychological and social factors, and smoking habits. In unadjusted analyses we found associations between allergic and non-allergic cutaneous reactions on patch testing and the two most severe groups of self-reported sensitivity to airborne chemicals. When adjusting for confounding, associations were weakened, and only non-allergic cutaneous reactions were significantly associated with individuals most severely affected by inhalation of airborne chemicals (odds ratio = 2.5, p = 0.006). Our results suggest that individuals with self-reported chemical sensitivity show increased non-allergic cutaneous reactions based on day 2 readings of patch tests. Copyright © 2011 Elsevier GmbH. All rights reserved.

Boehmite-An Efficient and Recyclable Acid-Base Bifunctional Catalyst for Aldol Condensation Reaction.

Science.gov (United States)

Reshma, P C Rajan; Vikneshvaran, Sekar; Velmathi, Sivan

2018-06-01

In this work boehmite was used as an acid-base bifunctional catalyst for aldol condensation reactions of aromatic aldehydes and ketones. The catalyst was prepared by simple sol-gel method using Al(NO3)3·9H2O and NH4OH as precursors. The catalyst has been characterized by X-ray diffraction (XRD), Fourier Transform Infrared (FTIR), Scanning Electron Microscopy (SEM), UV-visible spectroscopy (DRS), BET surface area analyses. Boehmite is successfully applied as catalyst for the condensation reaction between 4-nitrobenzaldehyde and acetone as a model substrate giving α, β-unsaturated ketones without any side product. The scope of the reaction is extended for various substituted aldehydes. A probable mechanism has been suggested to explain the cooperative behavior of the acidic and basic sites. The catalyst is environmentally friendly and easily recovered from the reaction mixture. Also the catalyst is reusable up to 3 catalytic cycles.

Reaction Decoder Tool (RDT): extracting features from chemical reactions.

Science.gov (United States)

Rahman, Syed Asad; Torrance, Gilliean; Baldacci, Lorenzo; Martínez Cuesta, Sergio; Fenninger, Franz; Gopal, Nimish; Choudhary, Saket; May, John W; Holliday, Gemma L; Steinbeck, Christoph; Thornton, Janet M

2016-07-01

Extracting chemical features like Atom-Atom Mapping (AAM), Bond Changes (BCs) and Reaction Centres from biochemical reactions helps us understand the chemical composition of enzymatic reactions. Reaction Decoder is a robust command line tool, which performs this task with high accuracy. It supports standard chemical input/output exchange formats i.e. RXN/SMILES, computes AAM, highlights BCs and creates images of the mapped reaction. This aids in the analysis of metabolic pathways and the ability to perform comparative studies of chemical reactions based on these features. This software is implemented in Java, supported on Windows, Linux and Mac OSX, and freely available at https://github.com/asad/ReactionDecoder : asad@ebi.ac.uk or s9asad@gmail.com. © The Author 2016. Published by Oxford University Press.

Recovery Of Valuable Metals In Tin-Based Anodic Slimes By Carbothermic Reaction

Directory of Open Access Journals (Sweden)

Han Chulwoong

2015-06-01

Full Text Available This study investigated the recovery of anodic slimes by carbothermic reaction in the temperature range of 973~1,273K and amount of carbon as a function of time. Tin anodic slime samples were collected from the bottom of the electrolytic cells during the electro-refining of tin. The anodic slimes are consisted of high concentrated tin, silver, copper and lead oxides. The kinetics of reduction were determined by means of the weight-loss measurement technique. In order to understand in detail of carbothermic reaction, thermodynamic calculation was carried out and compared with experiments. From thermodynamic calculation and experiment, it was confirmed that Sn-based anodic slime could be reduced by controlling temperature and amount of carbon. However, any tendency between the reduction temperature and carbon content for the reduction reaction was not observed.

Fabrication of Titanium Diboride-Cu Composite by Self-High Temperature Synthesis plus Quick Press

Institute of Scientific and Technical Information of China (English)

Jinyong ZHANG; Zhengyi FU; Weimin WANG

2005-01-01

Titanium diboride based composites, good candidates for contact materials, have high hardness, Young's modulus,high temperature stability, and excellent electrical, thermal conductivity. However a good interface of TiB2/Cu is very difficult to achieve for oxidation of TiB2. To avoid this oxidation behavior, the in situ combusting synthesis technology, SHS, was used to prepare TiB2/Cu composite. Thecharacters of Ti-B-xCu SHS were studied in detail,such as combustion temperature, products phases and grain size. Based on the experimental results a proper technology way of self-high temperature synthesis plus quick press (SHS/QP) was determined and compact TiB2/Cu composites with relative density over than 97 pct of the theoretical were fabricated by this method. The properties and microstructures of these TiB2 based composites were also investigated.

Are Canadian youth still exposed to second-hand smoke in homes and in cars?

Science.gov (United States)

Barisic, A; Leatherdale, S T; Burkhalter, R; Ahmed, R

2014-07-01

The objective of this manuscript is to examine the prevalence of youth exposed to second-hand smoke (SHS) in homes and cars, changes in SHS exposure over time, and factors associated with beliefs youth hold regarding SHS exposure among a nationally representative sample of Canadian youth. Descriptive analysis of SHS exposure in homes and cars was conducted using data from the Canadian Youth Smoking Survey (2004, 2006 and 2008). Logistic regression was conducted to examine factors associated with beliefs youth had about SHS exposure in 2008. In 2008, 21.5% of youth reported being exposed to SHS in their home on a daily or almost daily basis, while 27.3% reported being exposed to SHS while riding in a car at least once in the previous week. Between 2004 and 2008, the prevalence of daily SHS exposure in the home and cars decreased by 4.7% and 18.0% respectively. Despite reductions in SHS exposure over time, a substantial number of Canadian youth continue to be exposed to SHS in homes and cars. Further effort is required to implement and evaluate policies designed to protect youth from SHS.

Late adverse reactions to intravascular iodine based contrast media

DEFF Research Database (Denmark)

Bellin, Marie-France; Stacul, Fulvio; Webb, Judith A W

2011-01-01

DEFINITION: Late adverse reactions (LAR) to contrast media (CM) are defined as reactions occurring 1 h to 1 week after exposure. NEED FOR REVIEW: In view of more prospective studies of LAR and new data about their pathophysiology, the Contrast Medium Safety Committee (CMSC) of the European Society...... or delayed reading intradermal). The main risk factors for LAR are a previous reaction to contrast medium, a history of allergy, and interleukin-2 treatment. Most skin reactions are mild or moderate and self-limiting. MANAGEMENT: Management is symptomatic and similar to the management of other drug......-induced skin reactions. To reduce the risk of repeat reactions avoidance of the relevant CM and any cross-reacting agents identified by skin testing is recommended....

A Ligand Structure-Activity Study of DNA-Based Catalytic Asymmetric Hydration and Diels-Alder Reactions

NARCIS (Netherlands)

Rosati, F.; Roelfes, J.G.

A structure-activity relationship study of the first generation ligands for the DNA-based asymmetric hydration of enones and Diels-Alder reaction in water is reported. The design of the ligand was optimized resulting in a maximum ee of 83% in the hydration reaction and 75% in the Diels-Alder

Effect of SHS conditions on microstructure of NiTi shape memory alloy

Czech Academy of Sciences Publication Activity Database

Novák, P.; Mejzliková, L.; Michalcová, A.; Čapek, J.; Beran, Přemysl; Vojtěch, D.

2013-01-01

Roč. 42, NOV 2013 (2013), s. 85-91 ISSN 0966-9795 R&D Projects: GA ČR GBP108/12/G043; GA MŠk(XE) LM2011019 Institutional support: RVO:61389005 Keywords : intermetallics * miscellaneous * phase identification * reaction synthesis * electron microscopy * scanning Subject RIV: JG - Metallurgy Impact factor: 2.119, year: 2013

Proton conduction based on intracrystalline chemical reaction

International Nuclear Information System (INIS)

Schuck, G.; Lechner, R.E.; Langer, K.

2002-01-01

Proton conductivity in M 3 H(SeO 4 ) 2 crystals (M=K, Rb, Cs) is shown to be due to a dynamic disorder in the form of an intracrystalline chemical equilibrium reaction: alternation between the association of the monomers [HSeO 4 ] 1- and [SeO 4 ] 2- resulting in the dimer [H(SeO 4 ) 2 ] 3- (H-bond formation) and the dissociation of the latter into the two monomers (H-bond breaking). By a combination of quasielastic neutron scattering and FTIR spectroscopy, reaction rates were obtained, as well as rates of proton exchange between selenate ions, leading to diffusion. The results demonstrate that this reaction plays a central role in the mechanism of proton transport in these solid-state protonic conductors. (orig.)

Abstract ID: 240 A probabilistic-based nuclear reaction model for Monte Carlo ion transport in particle therapy.

Science.gov (United States)

Maria Jose, Gonzalez Torres; Jürgen, Henniger

2018-01-01

In order to expand the Monte Carlo transport program AMOS to particle therapy applications, the ion module is being developed in the radiation physics group (ASP) at the TU Dresden. This module simulates the three main interactions of ions in matter for the therapy energy range: elastic scattering, inelastic collisions and nuclear reactions. The simulation of the elastic scattering is based on the Binary Collision Approximation and the inelastic collisions on the Bethe-Bloch theory. The nuclear reactions, which are the focus of the module, are implemented according to a probabilistic-based model developed in the group. The developed model uses probability density functions to sample the occurrence of a nuclear reaction given the initial energy of the projectile particle as well as the energy at which this reaction will take place. The particle is transported until the reaction energy is reached and then the nuclear reaction is simulated. This approach allows a fast evaluation of the nuclear reactions. The theory and application of the proposed model will be addressed in this presentation. The results of the simulation of a proton beam colliding with tissue will also be presented. Copyright © 2017.

An experimental study of steam explosions involving CORIUM melts

International Nuclear Information System (INIS)

Millington, R.A.

1984-05-01

An experimental programme to investigate molten fuel coolant interactions involving 0.5 kg thermite-generated CORIUM melts and water has been carried out. System pressures and initial coolant subcoolings were chosen to enhance the probability of steam explosions. Yields and efficiencies of the interactions were found to be very close to those obtained from similar experiments using molten UO 2 generated from a Uranium/Molybdenum Trioxide thermite. (author)

Association of suboptimal health status with psychosocial stress, plasma cortisol and mRNA expression of glucocorticoid receptor α/β in lymphocyte.

Science.gov (United States)

Yan, Yu-Xiang; Dong, Jing; Liu, You-Qin; Zhang, Jie; Song, Man-Shu; He, Yan; Wang, Wei

2015-01-01

Suboptimal health status (SHS) has become a new public health challenge in China. This study investigated whether high SHS is associated with psychosocial stress, changes in cortisol level and/or glucocorticoid receptor (GR) isoform expression. Three-hundred eighty-six workers employed in three companies in Beijing were recruited. The SHS score was derived from data collection in the SHS questionnaire (SHSQ-25). The short standard version of the Copenhagen Psychosocial Questionnaire (COPSOQ) was used to assess job-related psychosocial stress. The mean value of the five scales of COPSOQ and distribution of plasma cortisol and mRNA expression of GRα/GRβ between the high level of SHS group and the low level of SHS group were compared using a general linear model procedure. Multiple linear regression analysis was used to analyze the effect of psychosocial stress on SHS. We identified three factors that were predictive of SHS, including "demands at work", "interpersonal relations and leadership" and "insecurity at work". Significantly higher levels of plasma cortisol and GRβ/GRα mRNA ratio were observed among the high SHS group. High level of SHS is associated with decreased mRNA expression of GRα. This study confirmed the association between chronic psychosocial stress and SHS, indicating that improving the psychosocial work environment may reduce SHS and then prevent chronic diseases effectively.

Secondhand tobacco smoke exposure differentially alters nucleus tractus solitarius neurons at two different ages in developing non-human primates

International Nuclear Information System (INIS)

Sekizawa, Shin-ichi; Joad, Jesse P.; Pinkerton, Kent E.; Bonham, Ann C.

2010-01-01

Exposing children to secondhand tobacco smoke (SHS) is associated with increased risk for asthma, bronchiolitis and SIDS. The role for changes in the developing CNS contributing to these problems has not been fully explored. We used rhesus macaques to test the hypothesis that SHS exposure during development triggers neuroplastic changes in the nucleus tractus solitarius (NTS), where lung sensory information related to changes in airway and lung function is first integrated. Pregnant monkeys were exposed to filtered air (FA) or SHS for 6 h/day, 5 days/week starting at 50-day gestational age. Mother/infant pairs continued the exposures postnatally to age 3 or 13 months, which may be equivalent to approximately 1 or 4 years of human age, respectively. Whole-cell recordings were made of second-order NTS neurons in transverse brainstem slices. To target the consequences of SHS exposure based on neuronal subgroups, we classified NTS neurons into two phenotypes, rapid-onset spiking (RS) and delayed-onset spiking (DS), and then evaluated intrinsic and synaptic excitabilities in FA-exposed animals. RS neurons showed greater cell excitability especially at age of 3 months while DS neurons received greater amplitudes of excitatory postsynaptic currents (EPSCs). Developmental neuroplasticity such as increases in intrinsic and synaptic excitabilities were detected especially in DS neurons. In 3 month olds, SHS exposure effects were limited to excitatory changes in RS neurons, specifically increases in evoked EPSC amplitudes and increased spiking responses accompanied by shortened action potential width. By 13 months, the continued SHS exposure inhibited DS neuronal activity; decreases in evoked EPSC amplitudes and blunted spiking responses accompanied by prolonged action potential width. The influence of SHS exposure on age-related and phenotype specific changes may be associated with age-specific respiratory problems, for which SHS exposure can increase the risk, such as SIDS

The healthcare costs of secondhand smoke exposure in rural China.

Science.gov (United States)

Yao, Tingting; Sung, Hai-Yen; Mao, Zhengzhong; Hu, Teh-wei; Max, Wendy

2015-10-01

The goal of this study was to assess the healthcare costs attributable to secondhand smoke (SHS) exposure among non-smoking adults (age ≥ 19) in rural China. We analysed data from the 2011 National Rural Household Survey which was conducted among adults in five provinces and one municipality in China (N=12,397). Respondents reported their smoking status, health conditions and healthcare expenditures. Relative risks were obtained from published sources. Healthcare costs included annual outpatient and inpatient hospitalisation expenditures for five SHS-related diseases: asthma, breast cancer (female only), heart disease, lung cancer and tuberculosis. SHS-attributable healthcare costs were estimated using a prevalence-based annual cost approach. The total healthcare costs of SHS exposure in rural China amounted to $1.2 billion in 2011, including $559 million for outpatient visits and $612.4 million for inpatient hospitalisations. The healthcare costs for women and men were $877.1 million and $294.3 million, respectively. Heart disease was the most costly condition for both women ($701.7 million) and men ($180.6 million). The total healthcare costs of SHS exposure in rural China accounted to 0.3% of China's national healthcare expenditures in 2011. Over one-fifth of the total healthcare costs of SHS exposure in rural China were paid by health insurance. The out-of-pocket expenditures per person accounted for almost half (47%) of their daily income. The adverse health effects of SHS exposure result in a large economic burden in China. Tobacco control policies that reduce SHS exposure could have an impact on reducing healthcare costs in China. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Coulometric bioelectrocatalytic reactions based on NAD-dependent dehydrogenases in tricarboxylic acid cycle

Energy Technology Data Exchange (ETDEWEB)

Fukuda, Jun [Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Sakyo-ku, Kyoto 606-8502 (Japan); Tsujimura, Seiya [Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Sakyo-ku, Kyoto 606-8502 (Japan)], E-mail: seiya@kais.kyoto-u.ac.jp; Kano, Kenji [Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Sakyo-ku, Kyoto 606-8502 (Japan)], E-mail: kkano@kais.kyoto-u.ac.jp

2008-12-30

This paper describes the characterization of mediated electro-enzymatic electrolysis systems based on NAD-dependent dehydrogenase reactions in the tricarboxylic acid (TCA) cycle. A micro-bulk electrolysis system with a carbon felt anode immersed in an electrolysis solution with a value of about 10 {mu}L was constructed for coulometric analysis of the substrate oxidation. Diaphorase (DI) was used to couple the NAD-dependent dehydrogenase reaction with the anode reaction of a suitable redox mediator. We focused on three types of NAD-dependant dehydrogenases reactions in this research: (1) isocitrate oxidation, in which the standard Gibbs energy change ({delta}G{sup o}') is negative; (2) {alpha}-ketoglutarate oxidation, which involves an electrochemically active coenzyme A (CoA); and (3) malate oxidation, which is thermodynamically unfavorable because of a large positive {delta}G{sup o}' value. The complete electrolysis of isocitrate was easily achieved, supporting the effective re-oxidation of NADH in the diaphorase-catalyzed electrochemical reaction. CoA was unfavorably oxidized at the electrodes in the presence of some mediators. The electrocatalytic oxidation of CoA was suppressed and the quantitative electrochemical oxidation of {alpha}-ketoglutarate was achieved by selecting a suitable mediator with negligibly slow electron transfer kinetics with CoA. The uphill malate oxidation was susceptible to product inhibition in the bioelectrochemical system, although NADH generated in the malate dehydrogenase reaction was immediately oxidized in the electrochemical system. The inhibition was successfully suppressed by linking citrate synthase to quench oxaloacetate and to make the total {delta}G{sup o}' value negative.

Coulometric bioelectrocatalytic reactions based on NAD-dependent dehydrogenases in tricarboxylic acid cycle

International Nuclear Information System (INIS)

Fukuda, Jun; Tsujimura, Seiya; Kano, Kenji

2008-01-01

This paper describes the characterization of mediated electro-enzymatic electrolysis systems based on NAD-dependent dehydrogenase reactions in the tricarboxylic acid (TCA) cycle. A micro-bulk electrolysis system with a carbon felt anode immersed in an electrolysis solution with a value of about 10 μL was constructed for coulometric analysis of the substrate oxidation. Diaphorase (DI) was used to couple the NAD-dependent dehydrogenase reaction with the anode reaction of a suitable redox mediator. We focused on three types of NAD-dependant dehydrogenases reactions in this research: (1) isocitrate oxidation, in which the standard Gibbs energy change (ΔG o ') is negative; (2) α-ketoglutarate oxidation, which involves an electrochemically active coenzyme A (CoA); and (3) malate oxidation, which is thermodynamically unfavorable because of a large positive ΔG o ' value. The complete electrolysis of isocitrate was easily achieved, supporting the effective re-oxidation of NADH in the diaphorase-catalyzed electrochemical reaction. CoA was unfavorably oxidized at the electrodes in the presence of some mediators. The electrocatalytic oxidation of CoA was suppressed and the quantitative electrochemical oxidation of α-ketoglutarate was achieved by selecting a suitable mediator with negligibly slow electron transfer kinetics with CoA. The uphill malate oxidation was susceptible to product inhibition in the bioelectrochemical system, although NADH generated in the malate dehydrogenase reaction was immediately oxidized in the electrochemical system. The inhibition was successfully suppressed by linking citrate synthase to quench oxaloacetate and to make the total ΔG o ' value negative

The impact of multiple interventions to reduce household exposure to second-hand tobacco smoke among women: a cluster randomized controlled trial in Kalutara district, Sri Lanka

Directory of Open Access Journals (Sweden)

A. M. A. A. P. Alagiyawanna

2017-10-01

Full Text Available Abstract Background Second-hand smoke (SHS in households remains a serious public health problem in Sri Lanka, partly due to a lack of voluntary prohibitions of tobacco smoking inside houses. Women are especially at risk of being exposed. Effective community based interventions to reduce the SHS in households targeting women is scarce. The objective of this study was to examine the impact of a multi-component intervention on household SHS exposure among Sri Lankan women. Methods Thirty clusters of 25 women (aged 18–65 from 750 households were randomized into the intervention and control groups. Women in the intervention group were exposed to activities which focused on improving knowledge on the health effects of SHS, attitudes towards SHS exposure, right to a smoke-free living and women empowerment against smoking. The duration of the intervention was six months. The comparison group received no intervention. The primary outcome of interest was self-reported SHS exposure in the household within 7 days prior to data collection. The secondary outcomes were exposure in the past 30 days, knowledge of the health risks of exposure, attitudes towards exposure, right to smoke-free living, women empowerment against smoking, and smoking inside the homes. Results Final assessment was in 329 (89.6% in the intervention group and 309 (85.8% in the comparison group. Following the intervention, significantly lower proportion of women in the intervention group as compared to the control group reported SHS exposure in their households within 7-days (9.2% vs. 15.3%, p = 0.02 and 30-days (13.6% vs. 21.6%, p = 0.008 prior to the post survey. As compared to the control group, significantly higher median scores were observed in the intervention group on the knowledge of the health risks of exposure to SHS (p < 0.001, attitudes on exposure to SHS (p = 0.004, right to smoke free living (p = 0.001 and women empowerment (p < 0.001. Conclusion Multi

Ontology aided modeling of organic reaction mechanisms with flexible and fragment based XML markup procedures.

Science.gov (United States)

Sankar, Punnaivanam; Aghila, Gnanasekaran

2007-01-01

The mechanism models for primary organic reactions encoding the structural fragments undergoing substitution, addition, elimination, and rearrangements are developed. In the proposed models, each and every structural component of mechanistic pathways is represented with flexible and fragment based markup technique in XML syntax. A significant feature of the system is the encoding of the electron movements along with the other components like charges, partial charges, half bonded species, lone pair electrons, free radicals, reaction arrows, etc. needed for a complete representation of reaction mechanism. The rendering of reaction schemes described with the proposed methodology is achieved with a concise XML extension language interoperating with the structure markup. The reaction scheme is visualized as 2D graphics in a browser by converting them into SVG documents enabling the desired layouts normally perceived by the chemists conventionally. An automatic representation of the complex patterns of the reaction mechanism is achieved by reusing the knowledge in chemical ontologies and developing artificial intelligence components in terms of axioms.

The Ni3Al and NiAl alloys: a class of intermetallics which can replace the Ni-base superalloys for the aerospace high temperature structural applications

International Nuclear Information System (INIS)

Lucaci, M.; Vidu, C.D.; Vasile, E.

2001-01-01

The paper presents the results obtained in synthesizing Ni-base refractory intermetallics from elemental powder mixes. In view of this, four mixes were made for the Ni 3 Al intermetallics and five mixes for the NiAl ones. The compound synthesis was made at T = 660 o C under vacuum by the SHS method, in the thermo-explosion mode. The variable parameters were the compacting pressure and the aluminum amount in the mixes. The obtained materials were then characterized by the microstructure and by the physical properties. The product synthesis degree was followed as well as their influence on the types of microstructures obtained. The reaction products were evidenced by x-ray diffraction and by quantitative chemical microanalysis. The obtained results revealed the formation of the Ni 3 Al compound having a primitive cubic crystal lattice with a 0 = 3,564 Aa and the formation of the NiAl compound, of a bcc lattice having a 0 = 2,86 Aa. Those obtained prove the ample influences of the powder homogeneity degree and of the powder purity on the possibility to produce an adequate synthesis, as well as the influence of the amount liquid appeared in the system on the synthesis degree, on the reaction rate and on the porosity of materials obtained. (author)

Family Smoking, Exposure to Secondhand Smoke at Home and Family Unhappiness in Children

Directory of Open Access Journals (Sweden)

Jian Jiu Chen

2015-11-01

Full Text Available Tobacco use adversely affects many aspects of well-being and is disliked by non-smokers. However, its association with family happiness is unknown. We investigated the associations of family unhappiness with smoking in family members and secondhand smoke (SHS exposure at home in Hong Kong children. In a school-based survey in 2012–2013, 1238 primary school students (mean age 8.5 years, standard deviation 0.9; 42.6% boys reported family smoking, SHS exposure at home and whether their families had any unpleasant experience caused by smoking or SHS in the past 30 days (tobacco-related unpleasant experience, and rated the overall level of happiness in their families (family unhappiness. Multivariable logistic regression was used to study the associations of tobacco-related unpleasant experience and family unhappiness with family smoking and SHS exposure at home. Tobacco-related unpleasant experience and family unhappiness were reported by 27.5% and 16.5% of students. Unpleasant experience was more strongly associated with family smoking than SHS exposure at home. Family unhappiness was associated with both family smoking (odds ratio 2.37; 95% confidence interval 1.51–3.71 and SHS exposure at home (1.82; 1.39–2.40. These results suggest a previously neglected possible impact of tobacco use on family happiness.

"Efforts to Reprioritise the Agenda" in China: British American Tobacco's Efforts to Influence Public Policy on Secondhand Smoke in China.

Directory of Open Access Journals (Sweden)

Monique E Muggli

2008-12-01

Full Text Available Each year, 540 million Chinese are exposed to secondhand smoke (SHS, resulting in more than 100,000 deaths. Smoke-free policies have been demonstrated to decrease overall cigarette consumption, encourage smokers to quit, and protect the health of nonsmokers. However, restrictions on smoking in China remain limited and ineffective. Internal tobacco industry documents show that transnational tobacco companies (TTCs have pursued a multifaceted strategy for undermining the adoption of restrictions on smoking in many countries.To understand company activities in China related to SHS, we analyzed British American Tobacco's (BAT's internal corporate documents produced in response to litigation against the major cigarette manufacturers to understand company activities in China related to SHS. BAT has carried out an extensive strategy to undermine the health policy agenda on SHS in China by attempting to divert public attention from SHS issues towards liver disease prevention, pushing the so-called "resocialisation of smoking" accommodation principles, and providing "training" for industry, public officials, and the media based on BAT's corporate agenda that SHS is an insignificant contributor to the larger issue of air pollution.The public health community in China should be aware of the tactics previously used by TTCs, including efforts by the tobacco industry to co-opt prominent Chinese benevolent organizations, when seeking to enact stronger restrictions on smoking in public places.

Cooperative Effects of Zwitterionic-Ionic Surfactant Mixtures on the Interfacial Water Structure Revealed by Sum Frequency Generation Vibrational Spectroscopy.

Science.gov (United States)

Pan, Xuecong; Yang, Fangyuan; Chen, Shunli; Zhu, Xuefeng; Wang, Chuanyi

2018-05-08

Cooperative effects of a series of equimolar binary zwitterionic-ionic surfactant mixtures on the interfacial water structure at the air-water interfaces have been studied by sum frequency generation vibrational spectroscopy (SFG-VS). For zwitterionic surfactant palmityl sulfobetaine (SNC 16 ), anionic surfactant sodium hexadecyl sulfate (SHS), and cationic surfactant cetyltrimethylammonium bromide (CTAB) with the same length of alkyl chain, significantly enhanced ordering of interfacial water molecules was observed for the zwitterionic-anionic surfactant mixtures SNC 16 -SHS, indicating that SNC 16 interacts more strongly with SHS than with CTAB because of the strong headgroup-headgroup electrostatic attraction for SNC 16 -SHS. Meanwhile, the SFG amplitude ratio of methyl and methylene symmetric stretching modes was used to verify the stronger interaction between SNC 16 and SHS. The conformational order indicator increased from 0.64 for SNC 16 to 7.17 for SNC 16 -SHS but only 0.94 for SNC 16 -CTAB. In addition, another anionic surfactant sodium dodecyl sulfate (SDS) was introduced to study the influence of chain-chain interaction. Decreased SFG amplitude of interfacial water molecules for SNC 16 -SDS was observed. Therefore, both the headgroup-headgroup electrostatic interaction and chain-chain van der Waals attractive interaction of the surfactants play an important role in enhancing the ordering of interfacial water molecules. The results provided experimental and theoretical bases for practical applications of the surfactants.

"Efforts to Reprioritise the Agenda" in China: British American Tobacco's Efforts to Influence Public Policy on Secondhand Smoke in China.

Science.gov (United States)

Muggli, Monique E; Lee, Kelley; Gan, Quan; Ebbert, Jon O; Hurt, Richard D

2008-12-23

Each year, 540 million Chinese are exposed to secondhand smoke (SHS), resulting in more than 100,000 deaths. Smoke-free policies have been demonstrated to decrease overall cigarette consumption, encourage smokers to quit, and protect the health of nonsmokers. However, restrictions on smoking in China remain limited and ineffective. Internal tobacco industry documents show that transnational tobacco companies (TTCs) have pursued a multifaceted strategy for undermining the adoption of restrictions on smoking in many countries. To understand company activities in China related to SHS, we analyzed British American Tobacco's (BAT's) internal corporate documents produced in response to litigation against the major cigarette manufacturers to understand company activities in China related to SHS. BAT has carried out an extensive strategy to undermine the health policy agenda on SHS in China by attempting to divert public attention from SHS issues towards liver disease prevention, pushing the so-called "resocialisation of smoking" accommodation principles, and providing "training" for industry, public officials, and the media based on BAT's corporate agenda that SHS is an insignificant contributor to the larger issue of air pollution. The public health community in China should be aware of the tactics previously used by TTCs, including efforts by the tobacco industry to co-opt prominent Chinese benevolent organizations, when seeking to enact stronger restrictions on smoking in public places.

Microwave-Assisted Synthesis of Nanoporous Aluminum-Based Coordination Polymers as Catalysts for Selective Sulfoxidation Reaction

Directory of Open Access Journals (Sweden)

Madhan Vinu

2017-10-01

Full Text Available A series of aluminum-based coordination polymers or metal–organic frameworks (Al–MOFs, i.e., DUT-4, DUT-5, MIL-53, NH2-MIL-53, and MIL-100, have been facile prepared by microwave (MW-assisted reactions and used as catalysts for selective sulfoxidation reactions. The MW-assisted synthesis drastically reduced the reaction time from few days to hours. The prepared MOFs have smaller and uniform particle sizes and better yield compared to conventional hydrothermal method. Furthermore, the Al–MOFs have been successfully demonstrated as catalysts in oxidation reaction of methyl phenyl sulfide with H2O2 as oxidant, even under mild conditions, with more than 95% conversion.

Microfabricated sleeve devices for chemical reactions

Science.gov (United States)

Northrup, M. Allen

2003-01-01

A silicon-based sleeve type chemical reaction chamber that combines heaters, such as doped polysilicon for heating, and bulk silicon for convection cooling. The reaction chamber combines a critical ratio of silicon and non-silicon based materials to provide the thermal properties desired. For example, the chamber may combine a critical ratio of silicon and silicon nitride to the volume of material to be heated (e.g., a liquid) in order to provide uniform heating, yet low power requirements. The reaction chamber will also allow the introduction of a secondary tube (e.g., plastic) into the reaction sleeve that contains the reaction mixture thereby alleviating any potential materials incompatibility issues. The reaction chamber may be utilized in any chemical reaction system for synthesis or processing of organic, inorganic, or biochemical reactions, such as the polymerase chain reaction (PCR) and/or other DNA reactions, such as the ligase chain reaction, which are examples of a synthetic, thermal-cycling-based reaction. The reaction chamber may also be used in synthesis instruments, particularly those for DNA amplification and synthesis.

A quantum theoretical study of reactions of methyldiazonium ion with DNA base pairs

International Nuclear Information System (INIS)

Shukla, P.K.; Ganapathy, Vinay; Mishra, P.C.

2011-01-01

Graphical abstract: Reactions of methyldiazonium ion at the different sites of the DNA bases in the Watson-Crick GC and AT base pairs were investigated employing density functional and second order Moller-Plesset (MP2) perturbation theories. Display Omitted Highlights: → Methylation of the DNA bases is important as it can cause mutation and cancer. → Methylation reactions of the GC and AT base pairs with CH 3 N 2 + were not studied earlier theoretically. → Experimental observations have been explained using theoretical methods. - Abstract: Methylation of the DNA bases in the Watson-Crick GC and AT base pairs by the methyldiazonium ion was investigated employing density functional and second order Moller-Plesset (MP2) perturbation theories. Methylation at the N3, N7 and O6 sites of guanine, N1, N3 and N7 sites of adenine, O2 and N3 sites of cytosine and the O2 and O4 sites of thymine were considered. The computed reactivities for methylation follow the order N7(guanine) > N3(adenine) > O6(guanine) which is in agreement with experiment. The base pairing in DNA is found to play a significant role with regard to reactivities of the different sites.

Preparation and Characterization of Enzyme Compartments in UV-Cured Polyurethane-Based Materials and Their Application in Enzymatic Reactions

Directory of Open Access Journals (Sweden)

Diana Uhrich

2017-11-01

Full Text Available The preparation and characterization of UV-cured polyurethane-based materials for the mild inclusion immobilization of enzymes was investigated. Full curing of the polymer precursor/enzyme solution mixture was realized by a short irradiation with UV-light at ambient temperatures. The included aqueous enzyme solution remains highly dispersed in the polymer material with an even size distribution throughout the polymer material. The presented concept provides stable enzyme compartments which were applied for an alcohol dehydrogenase-catalyzed reduction reaction in organic solvents. Cofactor regeneration was achieved by a substrate-coupled approach via 2-propanol or an enzyme-coupled approach by a glucose dehydrogenase. This reaction concept can also be used for a simultaneous application of contrary biocatalytic reaction conditions within an enzymatic cascade reaction. Independent polymer-based reaction compartments were provided for two incompatible enzymatic reaction systems (alcohol dehydrogenase and hydroxynitrile lyase, while the relevant reactants diffuse between the applied compartments.

PhreeqcRM: A reaction module for transport simulators based on the geochemical model PHREEQC

Science.gov (United States)

Parkhurst, David L.; Wissmeier, Laurin

2015-01-01

PhreeqcRM is a geochemical reaction module designed specifically to perform equilibrium and kinetic reaction calculations for reactive transport simulators that use an operator-splitting approach. The basic function of the reaction module is to take component concentrations from the model cells of the transport simulator, run geochemical reactions, and return updated component concentrations to the transport simulator. If multicomponent diffusion is modeled (e.g., Nernst–Planck equation), then aqueous species concentrations can be used instead of component concentrations. The reaction capabilities are a complete implementation of the reaction capabilities of PHREEQC. In each cell, the reaction module maintains the composition of all of the reactants, which may include minerals, exchangers, surface complexers, gas phases, solid solutions, and user-defined kinetic reactants.PhreeqcRM assigns initial and boundary conditions for model cells based on standard PHREEQC input definitions (files or strings) of chemical compositions of solutions and reactants. Additional PhreeqcRM capabilities include methods to eliminate reaction calculations for inactive parts of a model domain, transfer concentrations and other model properties, and retrieve selected results. The module demonstrates good scalability for parallel processing by using multiprocessing with MPI (message passing interface) on distributed memory systems, and limited scalability using multithreading with OpenMP on shared memory systems. PhreeqcRM is written in C++, but interfaces allow methods to be called from C or Fortran. By using the PhreeqcRM reaction module, an existing multicomponent transport simulator can be extended to simulate a wide range of geochemical reactions. Results of the implementation of PhreeqcRM as the reaction engine for transport simulators PHAST and FEFLOW are shown by using an analytical solution and the reactive transport benchmark of MoMaS.

Thermo-chemical characterization of a Al nanoparticle and NiO nanowire composite modified by Cu powder

International Nuclear Information System (INIS)

Bohlouli-Zanjani, Golnaz; Wen, John Z.; Hu, Anming; Persic, John; Ringuette, Sophie; Zhou, Y. Norman

2013-01-01

Highlights: • First study on the copper modified powder-type Al nanoparticle and NiO nanowire composites. • Experimental findings were unique in identifying the AlNi formation and comparing with the Al/CuO thermite. • Potential applications in material joining and bonding. - Abstract: Thermo-chemical properties of the Al nanoparticle and NiO nanowire composites modified by the micro-sized copper additive were investigated experimentally. Their onset temperatures of ignition and energy release data per mass were characterized using differential thermal analysis measurements. These microstructures and chemical compositions of reaction products were analyzed using scanning electron microscopy, energy dispersive X-ray spectroscopy and X-ray diffraction. The fuel-rich Al/NiO/Cu composites produced two types of metallic spheres. Copper spheres were formed from melting and solidification of the copper additive, while AlNi composite spheres were identified by the energy dispersive X-ray spectroscopy and X-ray diffraction analyses. It was found that the amount of the copper additive did not significantly influence the onset temperature of thermite peaks, but caused a dramatic change in energy release. The aforementioned ignition and energetic properties were compared with these from the Al nanoparticle and CuO nanowire composites

Controlling material reactivity using architecture

Science.gov (United States)

Sullivan, Kyle

2017-06-01

The reactivity of thermites can be tailored through selection of several parameters, and can range from very slow burns to rapid deflagrations. 3D printing is a rapidly emerging field, and offers the potential to build architected parts. Here we sought to explore whether controlling such features could be a suitable path forward for gaining additional control of the reactivity. This talk discusses several new methods for preparing thermite samples with controlled architectures using 3D printing. Additionally, we demonstrate that the architecture can play a role in the reactivity of an object. Our results suggest that architecture can be used to tailor the convective and/or advective energy transport during a deflagration, thus enhancing or retarding the reaction. The results are promising in that they give researchers an additional way of controlling the energy release rate without defaulting to the conventional approach of changing the formulation. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under contract DE-AC52-07NA27344. LLNL-ABS-708525. In collaboration with: Cheng Zhu, Eric Duoss, Matt Durban, Alex Gash, Alexandra Golobic, Michael Grapes, David Kolesky, Joshua Kuntz, Jennifer Lewis, Christopher Spadaccini; LAWRENCE LIVERMORE NATIONAL LAB.

Simulated fuel melt movement and relocation in two seven-pin-bundle geometries (SIMBATH out-of-pile experiments Vsub(Th) 74; Vsub(Th) 79)

International Nuclear Information System (INIS)

Peppler, W.; Menzenhauer, P.; Will, H.

1983-11-01

The SIMBATH program was initiated to investigate the physical phenomena of transient material movement and relocation during transient overpower (TOP) and loss of flow (LOF) driven TOP accidents in LMFBR's. The energy release during the accident is simulated out of pile by the reaction of a thermite mixture. Two 7-pin experiments have been performed using flowing sodium. In both tests the transient material movement has been recorded by X-ray-cinematography at about 1000 frames per second. The tests have been analysed. The dominant physical phenomena governing the material movement have been estimated. (orig.) [de

Molten core debris-sodium interactions: M-Series experiments

International Nuclear Information System (INIS)

Sowa, E.S.; Gabor, J.D.; Pavlik, J.R.; Cassulo, J.C.; Cook, C.J.; Baker, L. Jr.

1979-01-01

Five new kilogram-scale experiments have been carried out. Four of the experiments simulated the situation where molten core debris flows from a breached reactor vessel into a dry reactor cavity and is followed by a flow of sodium (Ex-vessel case) and one experiment simulated the flow of core debris into an existing pool of sodium (In-vessel case). The core debris was closely simulated by a thermite reaction which produced a molten mixture of UO 2 , ZrO 2 , and stainless steel. There was efficient fragmentation of the debris in all experiments with no explosive interactions observed

A Comparative Study of French and Turkish Students' Ideas on Acid-Base Reactions

Science.gov (United States)

Cokelez, Aytekin

2010-01-01

The goal of this comparative study was to determine the knowledge that French and Turkish upper secondary-school students (grades 11 and 12) acquire on the concept of acid-base reactions. Following an examination of the relevant curricula and textbooks in the two countries, 528 students answered six written questions about the acid-base concept.…

Immediate Adverse Reactions to Gadolinium-Based MR Contrast Media: A Retrospective Analysis on 10,608 Examinations

Directory of Open Access Journals (Sweden)

Vincenza Granata

2016-01-01

Full Text Available Background and Purpose. Contrast media (CM for magnetic resonance imaging (MRI may determine the development of acute adverse reactions. Objective was to retrospectively assess the frequency and severity of adverse reactions associated with gadolinium-based contrast agents (GBCAs injection in patients who underwent MRI. Material and Methods. At our center 10608 MRI examinations with CM were performed using five different GBCAs: Gd-BOPTA (MultiHance, Gd-DTPA (Magnevist, Gd-EOBDTPA (Primovist, Gd-DOTA (Dotarem, and Gd-BTDO3A (Gadovist. Results. 32 acute adverse reactions occurred, accounting for 0.3% of all administration. Twelve reactions were associated with Gd-DOTA injection (0.11%, 9 with Gd-BOPTA injection (0.08%, 6 with Gd-BTDO3A (0.056%, 3 with Gd-EOB-DTPA (0.028%, and 2 with Gd-DTPA (0.018%. Twenty-four reactions (75.0% were mild, four (12.5% moderate, and four (12.5% severe. The most severe reactions were seen associated with use of Gd-BOPTA, with 3 severe reactions in 32 total reactions. Conclusion. Acute adverse reactions are generally rare with the overall adverse reaction rate of 0.3%. The most common adverse reactions were not severe, consisting in skin rash and hives.

Trends in adult exposure to secondhand smoke in vehicles: Findings from the 2009-2012 Canadian Tobacco Use Monitoring Survey.

Science.gov (United States)

Azagba, Sunday

2015-10-01

A growing number of jurisdictions have implemented smoke-free vehicles when children are present due to the substantial health effects of secondhand smoke (SHS). Prior studies on the prevalence of SHS exposure in vehicles have mainly focused on adolescents. This study examined the prevalence and socio-demographic correlates of SHS exposure in vehicles among Canadian adults. A repeated cross-sectional data on youth and adult data were drawn from the 2009-2012 Canadian Tobacco Use Monitoring Survey (n=58, 195). Multivariable logistic regression analysis was used to examine the socio-demographic correlates of exposure to SHS in vehicles. Overall, 19% in 2009 and 18% in 2012 of adults reported SHS exposure in vehicles in the past month. Disparities in the SHS exposure prevalence were observed, with a higher SHS exposure among current smokers, former smokers, males, younger adults, living in a household with smoking-related exposure, and those with less education. The multivariable analyses showed significant associations between socio-demographic characteristics and SHS exposure. Higher odds SHS exposure was found for those younger (aged 20-24, OR=16.27, CI=11.09-23.88; 25-44, OR=6.12, CI=4.14-9.06; 45-64, OR=2.79, CI=1.95-4.02) compared to those aged 65 and over. Likewise, those with less education had greater odds of SHS exposure. Findings suggest that adults SHS exposure is high, especially for young adults and those with less education. Adult passengers may need protection from SHS given that no level of SHS exposure is safe. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Bulletin of Materials Science | Indian Academy of Sciences

Indian Academy of Sciences (India)

Thermodynamicevaluations of this system and its relevant subsystems revealed that TiB 2 –MgO composite powder can be easily produced by a SHS reaction. However, experimental results of a TiO 2 : B 2 O 3 : 5 Mg mixture heated in a domestic oven showed the formation of some intermediate compounds such as ...

Automated Prediction of Catalytic Mechanism and Rate Law Using Graph-Based Reaction Path Sampling.

Science.gov (United States)

Habershon, Scott

2016-04-12

In a recent article [ J. Chem. Phys. 2015 , 143 , 094106 ], we introduced a novel graph-based sampling scheme which can be used to generate chemical reaction paths in many-atom systems in an efficient and highly automated manner. The main goal of this work is to demonstrate how this approach, when combined with direct kinetic modeling, can be used to determine the mechanism and phenomenological rate law of a complex catalytic cycle, namely cobalt-catalyzed hydroformylation of ethene. Our graph-based sampling scheme generates 31 unique chemical products and 32 unique chemical reaction pathways; these sampled structures and reaction paths enable automated construction of a kinetic network model of the catalytic system when combined with density functional theory (DFT) calculations of free energies and resultant transition-state theory rate constants. Direct simulations of this kinetic network across a range of initial reactant concentrations enables determination of both the reaction mechanism and the associated rate law in an automated fashion, without the need for either presupposing a mechanism or making steady-state approximations in kinetic analysis. Most importantly, we find that the reaction mechanism which emerges from these simulations is exactly that originally proposed by Heck and Breslow; furthermore, the simulated rate law is also consistent with previous experimental and computational studies, exhibiting a complex dependence on carbon monoxide pressure. While the inherent errors of using DFT simulations to model chemical reactivity limit the quantitative accuracy of our calculated rates, this work confirms that our automated simulation strategy enables direct analysis of catalytic mechanisms from first principles.

Cesium Carbonate as a Heterogeneous Base Catalyst for Synthesis of 2-Aminothiophenes via Gewald Reaction

Energy Technology Data Exchange (ETDEWEB)

Moeinpour, Farid [Islamic Azad University, Bandar Abbas Branch, Abbas (Iran, Islamic Republic of); Omidinia, Raheleh; Dorostkar-Ahmadi, Nadieh; Khoshdeli, Bentalhoda [Islamic Azad University, Mashhad Branch, Mashhad (Iran, Islamic Republic of)

2011-06-15

We have reported a new simple catalytic method for the synthesis of 2-aminothiophenes via Gewald reaction using Cs{sub 2}CO{sub 3} as an efficient, reusable and green heterogeneous catalyst under heating conditions in refluxing ethanol. The catalyst could be recycled after a simple workup and reused at least three runs without appreciable reduction in its catalytic activity. Low catalyst loading, clean reaction profiles, simple experimental and workup procedures and high yields are some advantages of this protocol. The synthesis of substituted 2-aminothiophenes is attractive to chemical researchers as they are important intermediates in organic synthesis and frequently used as the scaffold motif of a variety of agrochemicals, dyes, and biologically active products. Thus, because of their wide utility, researchers have synthesized the substituted 2-aminothiophenes via efficient and convenient methods. The one-pot cyclocondensation of ketones with an activated α-hydrogen, a cyanomethylene containing an electron-withdrawing group such as cyanoacetate and elemental sulfur in the presence of organic base, for example, morpholine, diethylamine, etc, known as the Gewald reaction, has been one of the most well-studied multicomponent reactions in recent years. To extend the scope of the reaction, many alterations have been made to the original Gewald's base-catalyzed, two-component combination of α-mercapto ketones with cyanoacetate by varying the components and the conditions.

Diels-Alder reactions for the rational design of benzo[b]thiophenes: DFT-based guidelines for synthetic chemists

Science.gov (United States)

Brasca, Romina; Kneeteman, María N.; Mancini, Pedro M. E.; Fabian, Walter M. F.

2012-02-01

In this work we studied the capability of several diene/dienophile pairs to undergo Diels-Alder (DA) reactions leading to benzo[b]thiophenes. A variety of synthetically and commercially available nitrothiophenes were chosen as dienophiles. Methyl 5-nitro-3-thiophenecarboxylate was selected as a potential strong electrophilic candidate based on some DFT-based properties and the substitution pattern of the expected product. The mechanistic details concerning the participation of this dienophile in polar DA reactions were investigated through a theoretical point of view. The results were compared with the experimental outcomes. This methodology should allow synthetic chemists to analyze DA reactions in detail in a stage prior to the synthetic job.

Prospective randomized study of contrast reaction management curricula: Computer-based interactive simulation versus high-fidelity hands-on simulation

Energy Technology Data Exchange (ETDEWEB)

Wang, Carolyn L., E-mail: wangcl@uw.edu [Department of Radiology, University of Washington, Box 357115, 1959 NE Pacific Street, Seattle, WA 98195-7115 (United States); Schopp, Jennifer G.; Kani, Kimia [Department of Radiology, University of Washington, Box 357115, 1959 NE Pacific Street, Seattle, WA 98195-7115 (United States); Petscavage-Thomas, Jonelle M. [Penn State Hershey Medical Center, Department of Radiology, 500 University Drive, Hershey, PA 17033 (United States); Zaidi, Sadaf; Hippe, Dan S.; Paladin, Angelisa M.; Bush, William H. [Department of Radiology, University of Washington, Box 357115, 1959 NE Pacific Street, Seattle, WA 98195-7115 (United States)

2013-12-01

Purpose: We developed a computer-based interactive simulation program for teaching contrast reaction management to radiology trainees and compared its effectiveness to high-fidelity hands-on simulation training. Materials and methods: IRB approved HIPAA compliant prospective study of 44 radiology residents, fellows and faculty who were randomized into either the high-fidelity hands-on simulation group or computer-based simulation group. All participants took separate written tests prior to and immediately after their intervention. Four months later participants took a delayed written test and a hands-on high-fidelity severe contrast reaction scenario performance test graded on predefined critical actions. Results: There was no statistically significant difference between the computer and hands-on groups’ written pretest, immediate post-test, or delayed post-test scores (p > 0.6 for all). Both groups’ scores improved immediately following the intervention (p < 0.001). The delayed test scores 4 months later were still significantly higher than the pre-test scores (p ≤ 0.02). The computer group's performance was similar to the hands-on group on the severe contrast reaction simulation scenario test (p = 0.7). There were also no significant differences between the computer and hands-on groups in performance on the individual core competencies of contrast reaction management during the contrast reaction scenario. Conclusion: It is feasible to develop a computer-based interactive simulation program to teach contrast reaction management. Trainees that underwent computer-based simulation training scored similarly on written tests and on a hands-on high-fidelity severe contrast reaction scenario performance test as those trained with hands-on high-fidelity simulation.

Prospective randomized study of contrast reaction management curricula: Computer-based interactive simulation versus high-fidelity hands-on simulation

International Nuclear Information System (INIS)

Wang, Carolyn L.; Schopp, Jennifer G.; Kani, Kimia; Petscavage-Thomas, Jonelle M.; Zaidi, Sadaf; Hippe, Dan S.; Paladin, Angelisa M.; Bush, William H.

2013-01-01

Purpose: We developed a computer-based interactive simulation program for teaching contrast reaction management to radiology trainees and compared its effectiveness to high-fidelity hands-on simulation training. Materials and methods: IRB approved HIPAA compliant prospective study of 44 radiology residents, fellows and faculty who were randomized into either the high-fidelity hands-on simulation group or computer-based simulation group. All participants took separate written tests prior to and immediately after their intervention. Four months later participants took a delayed written test and a hands-on high-fidelity severe contrast reaction scenario performance test graded on predefined critical actions. Results: There was no statistically significant difference between the computer and hands-on groups’ written pretest, immediate post-test, or delayed post-test scores (p > 0.6 for all). Both groups’ scores improved immediately following the intervention (p < 0.001). The delayed test scores 4 months later were still significantly higher than the pre-test scores (p ≤ 0.02). The computer group's performance was similar to the hands-on group on the severe contrast reaction simulation scenario test (p = 0.7). There were also no significant differences between the computer and hands-on groups in performance on the individual core competencies of contrast reaction management during the contrast reaction scenario. Conclusion: It is feasible to develop a computer-based interactive simulation program to teach contrast reaction management. Trainees that underwent computer-based simulation training scored similarly on written tests and on a hands-on high-fidelity severe contrast reaction scenario performance test as those trained with hands-on high-fidelity simulation

Intensified Pozzolanic Reaction on Kaolinite Clay-Based Mortar

Directory of Open Access Journals (Sweden)

Yang-Hee Kwon

2017-05-01

Full Text Available The objective of this study is to develop and characterize kaolinite clay-based structural mortar. The pozzolanic reaction induced from two mineral additives, i.e., calcium hydroxide and silica fume (SF, and the physical filling effect from SF, were found to be effective on the enhancement of structural properties. Based on several preliminary experiments, 7:3 ratio of kaolinite clay/calcium hydroxide was selected as a basic binder. Then, the amount of SF was chosen as 0%, 7.5%, and 15% of the total binder to consider both the chemical and physical effects. The results showed that compressive strengths of samples with 7.5% and 15% SF are significantly increased by approximately 200% and 350%, respectively, at 28 days compared to the sample without SF. However, based on the results of the sample with 15% SF, it is found that excessive addition of SF causes long-term strength loss, possibly owing to micro cracks. With the careful consideration on this long-term behavior, this suggested new mix design can be further extended to develop sustainable structural materials using natural minerals or waste materials with nonbinding properties.

The effect of carbon mole ratio on the fabrication of silicon carbide

Directory of Open Access Journals (Sweden)

Sutham Niyomwas

2008-03-01

Full Text Available Silicon Carbide (SiC particles were synthesized by self-propagating high temperature synthesis (SHS from a powder mixture of SiO2-C-Mg. The reaction was carried out in a SHS reactor under static argon gas at a pressure of 0.5 MPa. The standard Gibbs energy minimization method was used to calculate the equilibrium composition of the reacting species. The effects of carbon mole ratio on the precursor mixture (C/SiO2/Mg: 1/1/2 to 3/1/2 and on the SiC conversion were investigated using X-ray diffraction and scanning electron microscope technique. The as-synthesized products of SiC-MgO powders were leached with 0.1M HCl acid solution to obtain the SiC particles.

Development of interactive graphic user interfaces for modeling reaction-based biogeochemical processes in batch systems with BIOGEOCHEM

Science.gov (United States)

Chang, C.; Li, M.; Yeh, G.

2010-12-01

The BIOGEOCHEM numerical model (Yeh and Fang, 2002; Fang et al., 2003) was developed with FORTRAN for simulating reaction-based geochemical and biochemical processes with mixed equilibrium and kinetic reactions in batch systems. A complete suite of reactions including aqueous complexation, adsorption/desorption, ion-exchange, redox, precipitation/dissolution, acid-base reactions, and microbial mediated reactions were embodied in this unique modeling tool. Any reaction can be treated as fast/equilibrium or slow/kinetic reaction. An equilibrium reaction is modeled with an implicit finite rate governed by a mass action equilibrium equation or by a user-specified algebraic equation. A kinetic reaction is modeled with an explicit finite rate with an elementary rate, microbial mediated enzymatic kinetics, or a user-specified rate equation. None of the existing models has encompassed this wide array of scopes. To ease the input/output learning curve using the unique feature of BIOGEOCHEM, an interactive graphic user interface was developed with the Microsoft Visual Studio and .Net tools. Several user-friendly features, such as pop-up help windows, typo warning messages, and on-screen input hints, were implemented, which are robust. All input data can be real-time viewed and automated to conform with the input file format of BIOGEOCHEM. A post-processor for graphic visualizations of simulated results was also embedded for immediate demonstrations. By following data input windows step by step, errorless BIOGEOCHEM input files can be created even if users have little prior experiences in FORTRAN. With this user-friendly interface, the time effort to conduct simulations with BIOGEOCHEM can be greatly reduced.

Person-based differences in pay reactions: A compensation-activation theory and integrative conceptual review.

Science.gov (United States)

Fulmer, Ingrid Smithey; Shaw, Jason D

2018-06-07

Compensation research has focused traditionally on how pay design characteristics (e.g., pay level, individual or group incentives) relate to average employee outcomes and, in toto, on how these outcomes affect organizational performance. Recently, scholars have begun to pay more attention to how individuals vary in the strength of their reactions to pay. Empirical research in several disciplines examines how the interplay of pay systems and person-based characteristics (psychological individual differences, demographics, and relative performance or position in a group) relate to important work-related outcomes. We develop a compensation-activation theory that frames compensation design characteristics as workplace "situations" providing cues that activate individuals' corresponding fundamental social motives made salient due to chronic or transient person-based characteristics. Where activation occurs, stronger-than-average responses to the compensation "situation" are expected. Using the theory as a lens, we synthesize and reinterpret existing research on person-based reactions to pay characteristics, including sorting, incentive/motivational effects, and effects on collective pay system reactions and unit/organizational outcomes. We conclude with a research agenda aimed at refining compensation-activation theory and advancing the study of compensation as it affects individual and organizational outcomes. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Fabricating Simple Wax Screen-Printing Paper-Based Analytical Devices to Demonstrate the Concept of Limiting Reagent in Acid- Base Reactions

Science.gov (United States)

Namwong, Pithakpong; Jarujamrus, Purim; Amatatongchai, Maliwan; Chairam, Sanoe

2018-01-01

In this article, a low-cost, simple, and rapid fabrication of paper-based analytical devices (PADs) using a wax screen-printing method is reported here. The acid-base reaction is implemented in the simple PADs to demonstrate to students the chemistry concept of a limiting reagent. When a fixed concentration of base reacts with a gradually…

Technical appraisal of solar home systems in Bangladesh: A field investigation

International Nuclear Information System (INIS)

Chowdhury, Shahriar A.; Islam, Moududul; Khan, M. Rezwan; Mourshed, Monjur; Morshed, Tanvir; Kabir, S.M. Raiyan; Patwary, Mohammad N.

2011-01-01

Solar Home System (SHS) based rural electrification has experienced a considerable growth in Bangladesh since the start of the Rural Electrification and Renewable Energy Development Project (REREDP) in 2003. The initial target of 50,000 SHS installations in off-grid areas was achieved within 2.5 years, 3 years ahead of schedule. After achieving a revised target of 200,000 SHSs, ahead of schedule in early 2009, a new target of 1 million SHS installations by 2012 was set. The installation of about 0.5 million systems by March 2010 indicates that the current target may well be achieved before the deadline. The size of the SHS market and its impact on the regeneration of the rural economy make it necessary to investigate the quality and reliability of the installed SHSs, if the continued success of the initiative is to be maintained. This paper reports on the findings from a field-based technical appraisal of SHS installations in Bangladesh. Sixty geographically dispersed installation sites were visited. Physical characteristics of the SHSs and their system components were tested to ascertain compliance with and deviations from the approved specifications. Despite the overwhelming success of the REREDP project, the study revealed various shortcomings. Notable among these are: incompatible and sub-optimal component configurations, faulty installations and a lack of effective quality assurance mechanism. The findings are contextualized and the ways to address the identified shortcomings are discussed. (author)

Systematic Survey of Serine Hydrolase Activity in Mycobacterium tuberculosis Defines Changes Associated with Persistence

Energy Technology Data Exchange (ETDEWEB)

Ortega, Corrie; Anderson, Lindsey N.; Frando, Andrew; Sadler, Natalie C.; Brown, Robert W.; Smith, Richard D.; Wright, Aaron T.; Grundner, Christoph

2016-02-01

The transition between replication and non-replication underlies much of Mycobacterium tuberculosis (Mtb) pathogenicity, as non- or slowly replicating Mtb are responsible for persistence and poor treatment outcomes. Therapeutic targeting of non-replicating, persistent populations is a priority for tuberculosis treatment, but only few drug targets in non-replicating Mtb are currently known. Here, we directly measure the activity of the highly diverse and druggable serine hydrolases (SHs) during active replication and non-replication by activity-based proteomics. We predict serine hydrolase activity for 78 proteins, including 27 proteins with previously unknown function, and identify 37 SHs that remain active even in the absence of replication, providing a set of candidate persistence targets. Non-replication was associated with large shifts in the activity of the majority of SHs. These activity changes were largely independent of SH abundance, indicating extensive post-translational regulation. By probing a large cross-section of druggable Mtb enzyme space during replication and non-replication, we identify new SHs and suggest new persistence targets.

Ultrasound-Accelerated Synthesis of Asymmetrical Thiosulfonate S-Esters by Base-Promoted Reaction of Sulfonyl Chlorides with Thiols

DEFF Research Database (Denmark)

Pham, Hien Thi; Nguyen, Ngoc-Lan Thi; Duus, Fritz

2015-01-01

Amberlyst A-26, Mg-Al hydrotalcite, potassium fluoride absorbed on alumina, triethylamine and pyridine have been tested as base catalysts and reagents for the reaction of sulfonyl chlorides with thiols to prepare thiosulfonate S-esters. The reactions were performed under solvent-free conditions...

Laser spot detection based on reaction diffusion

Czech Academy of Sciences Publication Activity Database

Vázquez-Otero, Alejandro; Khikhlukha, Danila; Solano-Altamirano, J. M.; Dormido, R.; Duro, N.

2016-01-01

Roč. 16, č. 3 (2016), s. 1-11, č. článku 315. ISSN 1424-8220 R&D Projects: GA MŠk EF15_008/0000162 Grant - others:ELI Beamlines(XE) CZ.02.1.01/0.0/0.0/15_008/0000162 Institutional support: RVO:68378271 Keywords : laser spot detection * laser beam detection * reaction diffusion models * Fitzhugh-Nagumo model * reaction diffusion computation * Turing patterns Subject RIV: BL - Plasma and Gas Discharge Physics OBOR OECD: Fluids and plasma physics (including surface physics) Impact factor: 2.677, year: 2016

Model Experiment of Thermal Runaway Reactions Using the Aluminum-Hydrochloric Acid Reaction

Science.gov (United States)

Kitabayashi, Suguru; Nakano, Masayoshi; Nishikawa, Kazuyuki; Koga, Nobuyoshi

2016-01-01

A laboratory exercise for the education of students about thermal runaway reactions based on the reaction between aluminum and hydrochloric acid as a model reaction is proposed. In the introductory part of the exercise, the induction period and subsequent thermal runaway behavior are evaluated via a simple observation of hydrogen gas evolution and…

Knowledge and adoption of solar home systems in rural Nicaragua

International Nuclear Information System (INIS)

Rebane, Kaja L.; Barham, Bradford L.

2011-01-01

Solar home systems (SHSs) are a promising electrification option for many households in the developing world. In most countries SHSs are at an early stage of dissemination, and thus face a hurdle common to many emerging alternative energy technologies: many people do not know enough about them to decide whether to adopt one or not. This study uses survey data collected in Nicaragua to investigate characteristics that predict the knowledge and adoption of SHSs among the rural population. First, a series of probit models is used to model the determinants of four measures of SHS knowledge. Next, a biprobit model with sample selection is employed to investigate the factors that predict SHS adoption, conditional on having sufficient knowledge to make an adoption decision. Comparison of the biprobit formulation to a standard probit model of adoption affirms its value. This study identifies multiple determinants of SHS knowledge and adoption, offers several practical recommendations to project planners, and provides an analytical framework for future work in this policy-relevant area. - Research highlights: → Solar home systems (SHSs) are a promising rural electrification option in the developing world. → As with many emerging renewable energy technologies, lack of knowledge may limit SHS adoption. → We use probit models to investigate the determinants of SHS knowledge in rural Nicaragua. → We also employ a biprobit model linking the determinants of knowledge and adoption. → We find that in analyzing SHS adoption, accounting for sample selection based on knowledge is key.

MALDI MS-based Composition Analysis of the Polymerization Reaction of Toluene Diisocyanate (TDI) and Ethylene Glycol (EG).

Science.gov (United States)

Ahn, Yeong Hee; Lee, Yeon Jung; Kim, Sung Ho

2015-01-01

This study describes an MS-based analysis method for monitoring changes in polymer composition during the polyaddition polymerization reaction of toluene diisocyanate (TDI) and ethylene glycol (EG). The polymerization was monitored as a function of reaction time using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI TOF MS). The resulting series of polymer adducts terminated with various end-functional groups were precisely identified and the relative compositions of those series were estimated. A new MALDI MS data interpretation method was developed, consisting of a peak-resolving algorithm for overlapping peaks in MALDI MS spectra, a retrosynthetic analysis for the generation of reduced unit mass peaks, and a Gaussian fit-based selection of the most prominent polymer series among the reconstructed unit mass peaks. This method of data interpretation avoids errors originating from side reactions due to the presence of trace water in the reaction mixture or MALDI analysis. Quantitative changes in the relative compositions of the resulting polymer products were monitored as a function of reaction time. These results demonstrate that the mass data interpretation method described herein can be a powerful tool for estimating quantitative changes in the compositions of polymer products arising during a polymerization reaction.

Pulmonary effects of active smoking and secondhand smoke exposure among adolescent students in Juárez, Mexico

Directory of Open Access Journals (Sweden)

Bird Y

2016-06-01

.61; FEV1/FVC =94.88±21.88; and FEF25%–75% =87.36±17.02 (P<0.001. Similarly, respiratory complaints were more prevalent among smokers and those exposed to SHS when compared to nonsmokers/nonexposed to SHS. Conclusion: Our findings suggest that initiation of cigarette smoking and, to a lesser extent, exposure to SHS in adolescence leads to increased respiratory symptoms and reduction of pulmonary function test values. Public health initiatives that aim to prevent smoking initiation, assist in cessation, and lessen SHS exposure of adolescents need to be school-based and employed as early as middle school. Keywords: adolescents, smoking, secondhand smoke exposure, respiratory symptoms, lung function

The Prevalence of Exposure to Workplace Secondhand Smoke in the United States: 2010 to 2015.

Science.gov (United States)

Dai, Hongying; Hao, Jianqiang

2017-11-01

To compare changes in exposure to workplace secondhand smoke (SHS) by industry of employment and occupation from 2010 to 2015. Data were collected from 2010 and 2015 National Health Interview Survey. Weighted estimates of the prevalence of exposure to workplace SHS among currently working nonsmokers in 2010 (n = 12 627) and 2015 (n = 16 399) were compared. The prevalence of exposure to workplace SHS among currently working nonsmokers was 10.0% in 2015 and 9.5% in 2010. Exposure to workplace SHS is disproportionally high among male workers, young workers, non-Hispanic blacks, Hispanics, workers with low education and low income, and workers residing in the Southern United States. Tobacco control policies have effectively reduced exposure to workplace SHS in a few white-collar and service job categories but blue-collar workers remain to have a high prevalence of exposure to workplace SHS. From 2010 to 2015, "transportation and warehousing industries" had the largest increase in SHS exposure (13.3%-21.5%, p value = .004) and "arts, entertainment, and recreation industries" had the largest decline in prevalence of exposure to SHS (20.1%-11.5%, p value = .01). In the multivariate analysis, workers with service (aOR = 1.4, p workplace SHS than those with white-collar occupations. Disparities of SHS exposure by industry, occupation, and social demographic class continue to exist. Blue-collar workers, especially those working in "transportation and construction industries," along with young workers and workers in high risk social classes are priority groups for future workplace SHS prevention. An estimated 12.6 million working nonsmokers were regularly exposed to SHS at work in 2015. We compared the changes in prevalence of exposure to workplace SHS from 2010 to 2015 by social demographic class, industry of employment and occupation. Our findings could help inform the policymakers and health practitioners to establish stronger smoke-free air laws and conduct education

One Minute of Marijuana Secondhand Smoke Exposure Substantially Impairs Vascular Endothelial Function.

Science.gov (United States)

Wang, Xiaoyin; Derakhshandeh, Ronak; Liu, Jiangtao; Narayan, Shilpa; Nabavizadeh, Pooneh; Le, Stephenie; Danforth, Olivia M; Pinnamaneni, Kranthi; Rodriguez, Hilda J; Luu, Emmy; Sievers, Richard E; Schick, Suzaynn F; Glantz, Stanton A; Springer, Matthew L

2016-07-27

Despite public awareness that tobacco secondhand smoke (SHS) is harmful, many people still assume that marijuana SHS is benign. Debates about whether smoke-free laws should include marijuana are becoming increasingly widespread as marijuana is legalized and the cannabis industry grows. Lack of evidence for marijuana SHS causing acute cardiovascular harm is frequently mistaken for evidence that it is harmless, despite chemical and physical similarity between marijuana and tobacco smoke. We investigated whether brief exposure to marijuana SHS causes acute vascular endothelial dysfunction. We measured endothelial function as femoral artery flow-mediated dilation (FMD) in rats before and after exposure to marijuana SHS at levels similar to real-world tobacco SHS conditions. One minute of exposure to marijuana SHS impaired FMD to a comparable extent as impairment from equal concentrations of tobacco SHS, but recovery was considerably slower for marijuana. Exposure to marijuana SHS directly caused cannabinoid-independent vasodilation that subsided within 25 minutes, whereas FMD remained impaired for at least 90 minutes. Impairment occurred even when marijuana lacked cannabinoids and rolling paper was omitted. Endothelium-independent vasodilation by nitroglycerin administration was not impaired. FMD was not impaired by exposure to chamber air. One minute of exposure to marijuana SHS substantially impairs endothelial function in rats for at least 90 minutes, considerably longer than comparable impairment by tobacco SHS. Impairment of FMD does not require cannabinoids, nicotine, or rolling paper smoke. Our findings in rats suggest that SHS can exert similar adverse cardiovascular effects regardless of whether it is from tobacco or marijuana. © 2016 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

Knowledge, attitudes, and behavior in avoiding secondhand smoke exposure among non-smoking employed women with higher education in Jordan.

Science.gov (United States)

Gharaibeh, Huda; Haddad, Linda; Alzyoud, Sukaina; El-Shahawy, Omar; Baker, Nesrin Abu; Umlauf, Mary

2011-11-01

Secondhand smoke (SHS) exposure is a serious public health threat worldwide; in the developing world there are less serious efforts towards controlling women's and children's exposure to SHS. Knowledge, attitudes and avoidance practices among Jordanian women have never been thoroughly studied. The purpose of this study was to assess the knowledge, attitudes, and avoidance behavior towards SHS exposure among employed Jordanian women with higher education. A survey was conducted among employed Jordanian women at two universities. A total of 209 women were included in the analysis. Two questionnaires regarding SHS exposure were used to measure knowledge, attitudes and avoidance practices. Most respondents were regularly exposed to SHS in various locations during daily life, even though they were very knowledgeable about the dangers of SHS exposure for women and children. However, the subject's attitudes and avoidance behavior did not reflect the level of knowledge about SHS risks. The results suggests there is a large discrepancy between SHS exposure, knowledge, attitudes and avoidance behavior among highly educated Jordanian women that is likely influenced by culture and traditional gender roles. Public health initiatives are needed in Jordan to address public policy, institutional practices and to empowerment of women to reduce SHS exposure.

Second-hand smoke exposure and mitigation strategies among home visitation workers.

Science.gov (United States)

Keske, Robyn R; Rees, Vaughan W; Behm, Ilan; Wadler, Brianna M; Geller, Alan C

2013-07-01

Protection of workers from second-hand smoke (SHS) in occupational settings is an important policy priority, yet little attention has been given to SHS protection for home visitation health workers, who number almost 2 million in the USA. Self-reported SHS exposure, SHS mitigation strategies and suggestions for further SHS exposure reduction approaches were obtained from home visitation health workers in Massachusetts. A cross-sectional survey was conducted among Massachusetts Early Intervention workers (N=316) at their state-wide conference in April 2010. Eighty-three per cent of respondents reported at least 1 hour per month of SHS exposure, and 16% reported at least 11 hours per month. Nevertheless, only 22% of workers counselled clients on maintaining a smoke-free home. Fewer than 30% of workers had ever voiced concerns to their employing agency, and just 12% had raised their concerns directly with clients. Only 14% stated that their agency had rules designed to protect workers from SHS. SHS exposure occurs frequently among home visitation health workers. The data point to a substantial population who are not protected from SHS exposure by formal policies.

Changes in child exposure to secondhand smoke after implementation of smoke-free legislation in Wales: a repeated cross-sectional study

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Holliday Jo

2009-01-01

Full Text Available Abstract Background Smoke-free legislation was introduced in Wales in April 2007. In response to concerns regarding potential displacement of smoking into the home following legislation, this study assessed changes in secondhand smoke (SHS exposure amongst non-smoking children. Methods Approximately 1,750 year 6 (aged 10-11 children from 75 Welsh primary schools were included in cross-sectional surveys immediately pre-legislation and one year later. Participants completed self-report questionnaires and provided saliva samples for cotinine assay. Regression analyses assessed the impact of legislation on children's SHS exposure at the population level, and amongst subgroups defined by parental figures who smoke within the home. Results Geometric mean salivary cotinine concentrations were 0.17 ng/ml (95% CI 0.15,0.20 pre-legislation and 0.15 ng/ml (95% CI 0.13,0.17, post-legislation, although this change was not statistically significant. Significant movement was however observed from the middle (0.10-0.50 ng/ml to lower tertile, though not from the higher end (>0.51 ng/ml to the middle. Reported exposure to SHS was greatest within the home. Home-based exposure did not change significantly post-legislation. Reported exposure in cafés or restaurants, buses and trains, and indoor leisure facilities fell significantly. The proportion of children reporting that parent figures smoked in the home declined (P = 0.03, with children with no parent figures who smoke in the home significantly more likely to provide saliva with cotinine concentrations of <0.10 ng/ml post-legislation. Amongst children with no parent figures who smoke in the home, the likelihood of 'not knowing' or 'never' being in a place where people were smoking increased post-legislation. Conclusion Smoke-free legislation in Wales did not increase SHS exposure in homes of children aged 10-11. Reported SHS exposure in public places fell significantly. The home remained the main source of

KATS experiments to simulate corium spreading in the EPR core catcher concept

International Nuclear Information System (INIS)

Eppinger, B.; Fieg, G.; Schuetz, W.; Stegmaier, U.

2001-01-01

In future Light Water Reactors special devices (core catchers) might be required to prevent containment failure by basement erosion after reactor pressure vessel melt-through during a core meltdown accident. Quick freezing of the molten core masses is desirable to reduce release of radioactivity. Several concepts of core catcher de-vices have been proposed based on the spreading of corium melt onto flat surfaces with subsequent cooling by flooding with water. Therefore a series of experiments to investigate high temperature melt spreading on flat surfaces has been carried out using alumina-iron thermite melts as a simulant. The oxidic thermite melt is conditioned by adding other oxides to simulate a realistic corium melt as close as possible. Spreading of oxidic and metallic melts have been performed in one- and two-dimensional geometry. Substrates were chemically inert ceramic layers, dry concrete and concrete with a shallow water layer on top. (authors)

A molecular dynamics study of intramolecular proton transfer reaction of malonaldehyde in solution based upon a mixed quantum-classical approximation. II. Proton transfer reaction in non-polar solvent

Science.gov (United States)

Kojima, H.; Yamada, A.; Okazaki, S.

2015-05-01

The intramolecular proton transfer reaction of malonaldehyde in neon solvent has been investigated by mixed quantum-classical molecular dynamics (QCMD) calculations and fully classical molecular dynamics (FCMD) calculations. Comparing these calculated results with those for malonaldehyde in water reported in Part I [A. Yamada, H. Kojima, and S. Okazaki, J. Chem. Phys. 141, 084509 (2014)], the solvent dependence of the reaction rate, the reaction mechanism involved, and the quantum effect therein have been investigated. With FCMD, the reaction rate in weakly interacting neon is lower than that in strongly interacting water. However, with QCMD, the order of the reaction rates is reversed. To investigate the mechanisms in detail, the reactions were categorized into three mechanisms: tunneling, thermal activation, and barrier vanishing. Then, the quantum and solvent effects were analyzed from the viewpoint of the reaction mechanism focusing on the shape of potential energy curve and its fluctuations. The higher reaction rate that was found for neon in QCMD compared with that found for water solvent arises from the tunneling reactions because of the nearly symmetric double-well shape of the potential curve in neon. The thermal activation and barrier vanishing reactions were also accelerated by the zero-point energy. The number of reactions based on these two mechanisms in water was greater than that in neon in both QCMD and FCMD because these reactions are dominated by the strength of solute-solvent interactions.

Global Controllability of Chemical Reactions

OpenAIRE

Drexler, Dániel András; Tóth, János

2015-01-01

Controllability of chemical reactions is an important problem in chemical engineering science. In control theory, analysis of the controllability of linear systems is well-founded, however the dynamics of chemical reactions is usually nonlinear. Global controllability properties of chemical reactions are analyzed here based on the Lie-algebra of the vector fields associated to elementary reactions. A chemical reaction is controllable almost everywhere if all the reaction rate coefficients can...

Catalyst Influence on Undesired Side Reactions in the Polycondensation of Fully Bio-Based Polyester Itaconates

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Ina Schoon

2017-12-01

Full Text Available Bio-based unsaturated polyester resins derived from itaconic acid can be an alternative to established resins of this type in the field of radical-curing resins. However, one of the challenges of these polyester itaconates is the somewhat more elaborate synthetic process, especially under polycondensation conditions used on an industrial scale. The α,β-unsaturated double bond of the itaconic acid is prone to side reactions that can lead to the gelation of the polyester resin under standard conditions. This is especially true when bio-based diols such as 1,3-propanediol or 1,4-butanediol are used to obtain resins that are 100% derived from renewable resources. It was observed in earlier studies that high amounts of these aliphatic diols in the polyester lead to low conversion and gelation of the resins. In this work, a catalytic study using different diols was performed in order to elucidate the reasons for this behavior. It was shown that the choice of catalyst has a crucial influence on the side reactions occurring during the polycondensation reactions. In addition, the side reactions taking place were identified and suppressed. These results will allow for the synthesis of polyester itaconates on a larger scale, setting the stage for their industrial application.

Everyday Prospective Memory and Executive Function Deficits Associated with Exposure to Second-Hand Smoke

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Thomas M. Heffernan

2013-01-01

Full Text Available This study explored whether exposure to second-hand smoke (SHS has a detrimental impact upon everyday memory in two groups of non-smokers; one which reported regular exposure to SHS and one that reported never having been exposed to SHS. Thirty-four non-smokers who reported having been regularly exposed to SHS (SHS group and 34 non-smokers who reported never having been exposed to SHS (non-SHS group were compared on self-reports of prospective memory (PM: remembering future intentions and/or activities and executive function (EF: those processes involved in attention, multitasking and decision-making. The Prospective and Retrospective Memory Questionnaire (PRMQ assessed everyday PM lapses; the Executive Function Questionnaire (EFQ assessed self-reported problems in EF; a drug-use questionnaire and a mood questionnaire were also administered. Two univariate ANCOVAs were applied to the PM and EF data, controlling for between-group differences in age, weekly alcohol use, anxiety and depression scores, and self-reported retrospective memory scores. The SHS group reported significantly more lapses on the PRMQ and more deficits on the EFQ than the non-SHS group. These findings provide new insights into PM and EF deficits associated with prolonged exposure to SHS in a group of non-smokers. Possible explanations and suggestions for future research are also considered.

On the rejection-based algorithm for simulation and analysis of large-scale reaction networks

Energy Technology Data Exchange (ETDEWEB)

Thanh, Vo Hong, E-mail: vo@cosbi.eu [The Microsoft Research-University of Trento Centre for Computational and Systems Biology, Piazza Manifattura 1, Rovereto 38068 (Italy); Zunino, Roberto, E-mail: roberto.zunino@unitn.it [Department of Mathematics, University of Trento, Trento (Italy); Priami, Corrado, E-mail: priami@cosbi.eu [The Microsoft Research-University of Trento Centre for Computational and Systems Biology, Piazza Manifattura 1, Rovereto 38068 (Italy); Department of Mathematics, University of Trento, Trento (Italy)

2015-06-28

Stochastic simulation for in silico studies of large biochemical networks requires a great amount of computational time. We recently proposed a new exact simulation algorithm, called the rejection-based stochastic simulation algorithm (RSSA) [Thanh et al., J. Chem. Phys. 141(13), 134116 (2014)], to improve simulation performance by postponing and collapsing as much as possible the propensity updates. In this paper, we analyze the performance of this algorithm in detail, and improve it for simulating large-scale biochemical reaction networks. We also present a new algorithm, called simultaneous RSSA (SRSSA), which generates many independent trajectories simultaneously for the analysis of the biochemical behavior. SRSSA improves simulation performance by utilizing a single data structure across simulations to select reaction firings and forming trajectories. The memory requirement for building and storing the data structure is thus independent of the number of trajectories. The updating of the data structure when needed is performed collectively in a single operation across the simulations. The trajectories generated by SRSSA are exact and independent of each other by exploiting the rejection-based mechanism. We test our new improvement on real biological systems with a wide range of reaction networks to demonstrate its applicability and efficiency.

Knock-out reactions

International Nuclear Information System (INIS)

de Forest, T. Jr.

1977-01-01

It is pointed out that the primary motivation for performing high energy single nucleon knock-out reactions is based on the concept of quasi-elastic scattering. The validity of and corrections to the partial wave impulse approximation and kinematical invariance of knock-out reactions and tests of the reaction mechanism are treated. The effect of distortions on the momentum distribution in the effective momentum approximation for given parameters are plotted. 12 references

Confining Domains Lead to Reaction Bursts: Reaction Kinetics in the Plasma Membrane

Science.gov (United States)

Kalay, Ziya; Fujiwara, Takahiro K.; Kusumi, Akihiro

2012-01-01

Confinement of molecules in specific small volumes and areas within a cell is likely to be a general strategy that is developed during evolution for regulating the interactions and functions of biomolecules. The cellular plasma membrane, which is the outermost membrane that surrounds the entire cell, was considered to be a continuous two-dimensional liquid, but it is becoming clear that it consists of numerous nano-meso-scale domains with various lifetimes, such as raft domains and cytoskeleton-induced compartments, and membrane molecules are dynamically trapped in these domains. In this article, we give a theoretical account on the effects of molecular confinement on reversible bimolecular reactions in a partitioned surface such as the plasma membrane. By performing simulations based on a lattice-based model of diffusion and reaction, we found that in the presence of membrane partitioning, bimolecular reactions that occur in each compartment proceed in bursts during which the reaction rate is sharply and briefly increased even though the asymptotic reaction rate remains the same. We characterized the time between reaction bursts and the burst amplitude as a function of the model parameters, and discussed the biological significance of the reaction bursts in the presence of strong inhibitor activity. PMID:22479350

Confining domains lead to reaction bursts: reaction kinetics in the plasma membrane.

Directory of Open Access Journals (Sweden)

Ziya Kalay

Full Text Available Confinement of molecules in specific small volumes and areas within a cell is likely to be a general strategy that is developed during evolution for regulating the interactions and functions of biomolecules. The cellular plasma membrane, which is the outermost membrane that surrounds the entire cell, was considered to be a continuous two-dimensional liquid, but it is becoming clear that it consists of numerous nano-meso-scale domains with various lifetimes, such as raft domains and cytoskeleton-induced compartments, and membrane molecules are dynamically trapped in these domains. In this article, we give a theoretical account on the effects of molecular confinement on reversible bimolecular reactions in a partitioned surface such as the plasma membrane. By performing simulations based on a lattice-based model of diffusion and reaction, we found that in the presence of membrane partitioning, bimolecular reactions that occur in each compartment proceed in bursts during which the reaction rate is sharply and briefly increased even though the asymptotic reaction rate remains the same. We characterized the time between reaction bursts and the burst amplitude as a function of the model parameters, and discussed the biological significance of the reaction bursts in the presence of strong inhibitor activity.

Youth exposure to in-vehicle second-hand smoke and their smoking behaviours: trends and associations in repeated national surveys (2006-2012).

Science.gov (United States)

Healey, Benjamin; Hoek, Janet; Wilson, Nick; Thomson, George; Taylor, Steve; Edwards, Richard

2015-03-01

To extend the limited international evidence on youth in-vehicle second-hand smoke (SHS) exposure by examining trends in New Zealand, a country with a national smoke-free goal and indoors smoke-free environment legislation. We tracked exposure rates and explored the associations between in-vehicle SHS exposure and smoking behaviours. In-home exposure was also examined for comparative purposes. Data were collected in annual surveys of over 25 000 year 10 school students (14-15-year olds) for a 7-year period (2006-2012). Questions covered smoking behaviour, exposure to smoking and demographics. Youth SHS exposure rates in-vehicle and in-home trended down slightly over time (pvehicle in the previous week in 2012. However, marked inequalities in exposure between ethnic groups, and by school-based socioeconomic position, persisted. The strongest association with SHS exposure was parental smoking (eg, for both parents versus neither smoking in 2012: in-vehicle SHS exposure adjusted OR: 7.4; 95% CI: 6.5 to 8.4). After adjusting for seven other factors associated with initiation, logistic regression analyses revealed statistically significant associations of in-vehicle SHS exposure with susceptibility to initiation and smoking. The slow decline in SHS exposure in vehicles and the lack of progress in reducing relative inequalities is problematic. To accelerate progress, the New Zealand Government could follow the example of other jurisdictions and prohibit smoking in cars carrying children. Other major policy interventions, beside enhanced smoke-free environments, will also likely be required if New Zealand is to achieve its 2025 smoke-free nation goal. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Secondhand smoke exposure at home among one billion children in 21 countries: findings from the Global Adult Tobacco Survey (GATS).

Science.gov (United States)

Mbulo, Lazarous; Palipudi, Krishna Mohan; Andes, Linda; Morton, Jeremy; Bashir, Rizwan; Fouad, Heba; Ramanandraibe, Nivo; Caixeta, Roberta; Dias, Rula Cavaco; Wijnhoven, Trudy M A; Kashiwabara, Mina; Sinha, Dhirendra N; Tursan d'Espaignet, Edouard

2016-12-01

Children are vulnerable to secondhand smoke (SHS) exposure because of limited control over their indoor environment. Homes remain the major place where children may be exposed to SHS. Our study examines the magnitude, patterns and determinants of SHS exposure in the home among children in 21 countries (19 low-income and middle-income countries and 2 high-income countries). Global Adult Tobacco Survey (GATS) data, a household survey of people 15 years of age or older. Data collected during 2009-2013 were analysed to estimate the proportion of children exposed to SHS in the home. GATS estimates and 2012 United Nations population projections for 2015 were also used to estimate the number of children exposed to SHS in the home. The proportion of children younger than 15 years of age exposed to SHS in the home ranged from 4.5% (Panama) to 79.0% (Indonesia). Of the approximately one billion children younger than 15 years of age living in the 21 countries under study, an estimated 507.74 million were exposed to SHS in the home. China, India, Bangladesh, Indonesia and the Philippines accounted for almost 84.6% of the children exposed to SHS. The prevalence of SHS exposure was higher in countries with higher adult smoking rates and was also higher in rural areas than in urban areas, in most countries. A large number of children were exposed to SHS in the home. Encouraging of voluntary smoke-free rules in homes and cessation in adults has the potential to reduce SHS exposure among children and prevent SHS-related diseases and deaths. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Entropy-based critical reaction time for mixing-controlled reactive transport

DEFF Research Database (Denmark)

Chiogna, Gabriele; Rolle, Massimo

2017-01-01

Entropy-based metrics, such as the dilution index, have been proposed to quantify dilution and reactive mixing in solute transport problems. In this work, we derive the transient advection dispersion equation for the entropy density of a reactive plume. We restrict our analysis to the case where...... the concentration distribution of the transported species is Gaussian and we observe that, even in case of an instantaneous complete bimolecular reaction, dilution caused by dispersive processes dominates the entropy balance at early times and results in the net increase of the entropy density of a reactive species...

Does shoe heel design influence ground reaction forces and knee moments during maximum lunges in elite and intermediate badminton players?

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Wing-Kai Lam

Full Text Available Lunge is one frequently executed movement in badminton and involves a unique sagittal footstrike angle of more than 40 degrees at initial ground contact compared with other manoeuvres. This study examined if the shoe heel curvature design of a badminton shoe would influence shoe-ground kinematics, ground reaction forces, and knee moments during lunge.Eleven elite and fifteen intermediate players performed five left-forward maximum lunge trials with Rounded Heel Shoe (RHS, Flattened Heel Shoe (FHS, and Standard Heel Shoes (SHS. Shoe-ground kinematics, ground reaction forces, and knee moments were measured by using synchronized force platform and motion analysis system. A 2 (Group x 3 (Shoe ANOVA with repeated measures was performed to determine the effects of different shoes and different playing levels, as well as the interaction of two factors on all variables.Shoe effect indicated that players demonstrated lower maximum vertical loading rate in RHS than the other two shoes (P < 0.05. Group effect revealed that elite players exhibited larger footstrike angle, faster approaching speed, lower peak horizontal force and horizontal loading rates but higher vertical loading rates and larger peak knee flexion and extension moments (P < 0.05. Analysis of Interactions of Group x Shoe for maximum and mean vertical loading rates (P < 0.05 indicated that elite players exhibited lower left maximum and mean vertical loading rates in RHS compared to FHS (P < 0.01, while the intermediate group did not show any Shoe effect on vertical loading rates.These findings indicate that shoe heel curvature would play some role in altering ground reaction force impact during badminton lunge. The differences in impact loads and knee moments between elite and intermediate players may be useful in optimizing footwear design and training strategy to minimize the potential risks for impact related injuries in badminton.

Knowledge, Attitudes, and Behavior in Avoiding Secondhand Smoke Exposure Among Non-Smoking Employed Women with Higher Education in Jordan

Directory of Open Access Journals (Sweden)

Mary Umlauf

2011-11-01

Full Text Available Secondhand smoke (SHS exposure is a serious public health threat worldwide; in the developing world there are less serious efforts towards controlling women’s and children’s exposure to SHS. Knowledge, attitudes and avoidance practices among Jordanian women have never been thoroughly studied. The purpose of this study was to assess the knowledge, attitudes, and avoidance behavior towards SHS exposure among employed Jordanian women with higher education. Methods: A survey was conducted among employed Jordanian women at two universities. A total of 209 women were included in the analysis. Two questionnaires regarding SHS exposure were used to measure knowledge, attitudes and avoidance practices. Results: Most respondents were regularly exposed to SHS in various locations during daily life, even though they were very knowledgeable about the dangers of SHS exposure for women and children. However, the subject’s attitudes and avoidance behavior did not reflect the level of knowledge about SHS risks. The results suggests there is a large discrepancy between SHS exposure, knowledge, attitudes and avoidance behavior among highly educated Jordanian women that is likely influenced by culture and traditional gender roles. Public health initiatives are needed in Jordan to address public policy, institutional practices and to empowerment of women to reduce SHS exposure.

Acceptance and willingness to pay for solar home system: Survey evidence from northern area of Pakistan

Directory of Open Access Journals (Sweden)

Abdullah

2017-11-01

Full Text Available The importance of solar energy has been accepted worldwide for the generation of electricity, but unfortunately, Pakistan has yet to exert efforts on the development of this source of energy. The purpose of this research is to explore the public acceptance and interest in solar home system (SHS. Moreover, the expectations of the public towards SHS development in Pakistan and the difficulties they face in SHS usage are identified. The result of the survey indicates that about 81% of the respondents show higher interest in SHS. However, many respondents claim that some hindrances obstruct them from using SHS which includes; high cost of solar panels, lack of information and trust on solar panel providers. Almost 60% of the respondents expect that government provision of incentives could be the best way to boost the usage of SHS countrywide. For the successful implementation of new SHS policy, the government of Pakistan needs to establish solar power plants, increase installation of solar panels, provides funding and full information for conducting independent research. In addition, almost 90% of the respondents believe that government should take the lead in developing the SHS sector. Therefore, this study provides some valuable references for SHS promotion in Pakistan.

Modelling Students' Visualisation of Chemical Reaction

Science.gov (United States)

Cheng, Maurice M. W.; Gilbert, John K.

2017-01-01

This paper proposes a model-based notion of "submicro representations of chemical reactions". Based on three structural models of matter (the simple particle model, the atomic model and the free electron model of metals), we suggest there are two major models of reaction in school chemistry curricula: (a) reactions that are simple…

A cellular automata approach to chemical reactions : 1 reaction controlled systems

NARCIS (Netherlands)

Korte, de A.C.J.; Brouwers, H.J.H.

2013-01-01

A direct link between the chemical reaction controlled (shrinking core) model and cellular automata, to study the dissolution of particles, is derived in this paper. Previous research on first and second order reactions is based on the concentration of the reactant. The present paper describes the

High-precision (p,t) reactions to determine reaction rates of explosive stellar processes

NARCIS (Netherlands)

Matić, Andrija

2007-01-01

The aim of my study was to investigate the nuclear structure of 22Mg and 26Si. These two nuclei play a significant role in stellar reaction processes at high temperatures. On base of the obtained nuclear structure we calculated the stellar reaction rates for the following reactions: 18Ne(α,p)21Na,

Commonly used air filters fail to eliminate secondhand smoke induced oxidative stress and inflammatory responses.

Science.gov (United States)

Muthumalage, Thivanka; Pritsos, Karen; Hunter, Kenneth; Pritsos, Chris

2017-07-01

Secondhand smoke (SHS) causes approximately 50,000 deaths per year. Despite all the health warnings, smoking is still allowed indoors in many states exposing both workers and patrons to SHS on a daily basis. The opponents of smoking bans suggest that present day air filtration systems remove the health hazards of exposure to SHS. In this study, using an acute SHS exposure model, we looked at the impact of commonly used air filters (MERV-8 pleated and MERV-8 pleated activated charcoal) on SHS by assessing the inflammatory response and the oxidative stress response in C57BL/6 mice. In order to assess the inflammatory response, we looked at the tumor necrosis factor alpha (TNF-α) cytokine production by alveolar macrophages (AMs), and for the oxidative response, we quantified the products of lipid peroxidation and the total glutathione (tGSH) production in lung homogenates. Our results showed that SHS caused significant immune and oxidative stress responses. The tested filters resulted in only a modest alleviation of inflammatory and oxidative responses due to SHS exposure. Our data show that these air filters cannot eliminate the risk of SHS exposure and that a short-term exposure to SHS is sufficient to alter the inflammatory cytokine response and to initiate a complex oxidative stress response. Our results are consistent with the statement made by the Surgeon General's reports that there is no risk free level of exposure to SHS.

Prevalence and Associated Factors of Secondhand Smoke Exposure among Internal Chinese Migrant Women of Reproductive Age: Evidence from China's Labor-Force Dynamic Survey.

Science.gov (United States)

Gong, Xiao; Luo, Xiaofeng; Ling, Li

2016-04-01

Secondhand smoke (SHS) is a major risk factor for poor health outcomes among women in China, where proportionately few women smoke. This is especially the case as it pertains to women's reproductive health, specifically migrant women who are exposed to SHS more than the population at large. There are several factors which may increase migrant women's risk of SHS exposure. This paper aims to investigate the prevalence and associated factors of SHS exposure among internal Chinese migrant women of reproductive age. The data used were derived from the 2014 Chinese Labor Dynamic Survey, a national representative panel survey. The age-adjusted rate of SHS exposure of women of reproductive age with migration experience was of 43.46% (95% CI: 40.73%-46.40%), higher than those without migration experience (35.28% (95% CI: 33.66%-36.97%)). Multivariate analysis showed that participants with a marital status of "Widowed" had statistically lower exposure rates, while those with a status of "Cohabitation" had statistically higher exposure. Those with an undergraduate degree or above had statistically lower SHS exposure. Those with increasing levels of social support, and those who currently smoke or drink alcohol, had statistically higher SHS exposure. Participants' different work-places had an effect on their SHS exposure, with outdoor workers statistically more exposed. Our findings suggest that urgent tobacco control measures should be taken to reduce smoking prevalence and SHS exposure. Specific attention should be paid to protecting migrant women of reproductive age from SHS.

Thermal process for immobilization of radioactive wastes

International Nuclear Information System (INIS)

Brownell, L.E.; Isaacson, R.E.; Kupfer, M.J.; Schulz, W.W.

1971-01-01

The Thermalt process involves an exothermic, thermite-like reaction of aluminum metal with basalt, quartz sand, and radioactive waste. The resulting melt when solidified is a silicious stone-like material that is similar in chemical composition to basalt. The process utilizes low cost ingredients: basalt rock, which occurs naturally in the Hanford region, inexpensive aluminum metal such as aluminum scrap which need not be pure, and the waste which is predominately sodium nitrate salt. The waste itself along with the basalt provides the oxygen necessary for the reaction. The exothermic reaction provides the necessary heat to melt the ingredients thus eliminating the need for external heat sources such as furnaces which are necessary with most other melt methods. The final product is highly stable and essentially nonleachable; leach rates appear as low or lower than other melt products described in the literature. Initial studies indicate the process is effective for both low-level and high-level wastes. (U.S.)

Smoke-Free Public Policies and Voluntary Policies in Personal Settings in Tbilisi, Georgia: A Qualitative Study.

Science.gov (United States)

Berg, Carla J; Smith, Samantha A; Bascombe, Ta Misha; Maglakelidze, Nino; Starua, Lela; Topuridze, Marina

2016-01-25

Georgia has limited tobacco control policies, particularly in the area of smoke-free public policies, which may influence the adoption of smoke-free home rules. We qualitatively examined knowledge about and reactions to public and personal smoke-free policies among Tbilisi residents. In Spring 2014, we conducted six focus groups among 47 total participants--two among male smokers, one among male nonsmokers, two among female smokers, and one among female nonsmokers. Our sample was 48.9% male and 70.2% past 30-day smokers. Most believed that SHS was dangerous, with particular concern regarding the impact of SHS on children and pregnant women. Many had misconceptions about how to protect others from SHS and the effectiveness of some approaches. Many indicated that they had some type of home rules, but few reported a complete ban on smoking in the home. Even when some restrictions were in place, they rarely were effective or enforced. Common concerns about the partial smoke-free public policy in Georgia included its economic impact, perceived discrimination among smokers, and the policy being against the Georgian culture. These concerns were heightened when participants were asked about the possible implementation of a complete smoke-free policy. Educational programs are needed to promote smoke-free policies in Georgia.

Lifetime secondhand smoke exposure and childhood and adolescent asthma: findings from the PIAMA cohort.

Science.gov (United States)

Milanzi, Edith B; Brunekreef, Bert; Koppelman, Gerard H; Wijga, Alet H; van Rossem, Lenie; Vonk, Judith M; Smit, Henriëtte A; Gehring, Ulrike

2017-02-23

Secondhand smoke (SHS) exposure is a modifiable risk factor associated with childhood asthma. Associations with adolescent asthma and the relevance of the timing and patterns of exposure are unclear. Knowledge of critical windows of exposure is important for targeted interventions. We used data until age 17 from 1454 children of the Dutch population-based PIAMA birth cohort. Residential SHS exposure was assessed through parental questionnaires completed at ages 3 months, 1-8 (yearly), 11, 14, and 17 years. Lifetime exposure was determined as; a) time window-specific exposure (prenatal, infancy, preschool, primary school, and secondary school); b) lifetime cumulative exposure; c) longitudinal exposure patterns using latent class growth modeling (LCGM). Generalized estimation equations and logistic regression were used to analyze associations between exposure and asthma at ages 4 to 17 years, adjusting for potential confounders. With all three methods, we consistently found no association between SHS exposure and asthma at ages 4 to 17 years e.g. adjusted overall odds ratio (95% confidence interval) 0.67 (0.41-1.12), 1.00 (0.66-1.51) and 0.67 (0.41-1.11) for prenatal maternal active smoking, infancy, and preschool school time window exposures, respectively. We assessed lifetime SHS exposure using different methods. Different timing and patterns of SHS exposure were not associated with an increased risk of asthma in childhood and adolescence in our study. More longitudinal studies could investigate effects of lifetime SHS exposure on asthma in adolescence and later life.

Phosphite radicals and their reactions. Examples of redox, substitution, and addition reactions

International Nuclear Information System (INIS)

Schaefer, K.; Asmus, K.D.

1980-01-01

Phosphite radicals HPO 3 - and PO 3 2 -, which exist in an acid-base equilibrium with pK = 5.75, are shown to take part in various types of reactions. In the absence of scavengers, they disappear mainly by second-order disproportionation and combination; a first-order contribution to the decay is also indicated. HPO 3 - and PO 3 2 - are good reductants toward electron acceptors such as tetranitromethane. In this reaction phosphate and C(NO 2 ) 3 - are formed. Phosphite radicals can, however, also act as good oxidants, e.g., toward thiols and thiolate ions. These reactions lead to the formation of RS. radicals which were identified either directly, as in the case of penicillamine, through the optical absorption of PenS. or more indirectly through equilibration of RS. with RS- to the optically absorbing RSSR-. disulfide radical anion. A homolytic substitution reaction (S/sub H/2) occurs in the reaction of the phosphite radicals with aliphatic disulfides, yielding RS. radicals and phosphate thioester RSPO 3 2 -. Lipoic acid, as an example of a cyclic disulfide, is reduced to the corresponding RSSR-. radical anion and also undergoes the S/sub H/2 reaction with about equal probability. An addition reaction is observed between phosphite radicals and molecular oxygen. The resulting peroxo phosphate radicals establish an acid-base equilibrium HPO 5 - . reversible PO 5 2- . + H+ with a pK = 3.4. Absolute rate constants were determined for all reactions discussed

Substrate dependent reaction channels of the Wolff–Kishner reduction reaction: A theoretical study

Directory of Open Access Journals (Sweden)

Shinichi Yamabe

2014-01-01

Full Text Available Wolff–Kishner reduction reactions were investigated by DFT calculations for the first time. B3LYP/6-311+G(d,p SCRF=(PCM, solvent = 1,2-ethanediol optimizations were carried out. To investigate the role of the base catalyst, the base-free reaction was examined by the use of acetone, hydrazine (H2N–NH2 and (H2O8. A ready reaction channel of acetone → acetone hydrazine (Me2C=N–NH2 was obtained. The channel involves two likely proton-transfer routes. However, it was found that the base-free reaction was unlikely at the N2 extrusion step from the isopropyl diimine intermediate (Me2C(H–N=N–H. Two base-catalyzed reactions were investigated by models of the ketone, H2N–NH2 and OH−(H2O7. Here, ketones are acetone and acetophenone. While routes of the ketone → hydrazone → diimine are similar, those from the diimines are different. From the isopropyl diimine, the N2 extrusion and the C–H bond formation takes place concomitantly. The concomitance leads to the propane product concertedly. From the (1-phenylethyl substituted diimine, a carbanion intermediate is formed. The para carbon of the phenyl ring of the anion is subject to the protonation, which leads to a 3-ethylidene-1,4-cyclohexadiene intermediate. Its [1,5]-hydrogen migration gives the ethylbenzene product. For both ketone substrates, the diimines undergoing E2 reactions were found to be key intermediates.

Isotope exchange reaction of tritium on precious metal catalyst based on cation-exchanged mordenite for blanket tritium recovery

Energy Technology Data Exchange (ETDEWEB)

Kawamura, Yoshinori, E-mail: kawamura.yoshinori@jaea.go.jp [Japan Atomic Energy Agency, 801-1 Mukoyama, Naka, Ibaraki 311-0193 (Japan); Hayashi, Takumi [Japan Atomic Energy Agency, 2-4 Shirane Shirakata, Tokai, Ibaraki 319-1195 (Japan); Yamanishi, Toshihiko [Japan Atomic Energy Agency, 2-166 Omotedate Obuchi, Rokkasho, Aomori 039-3212 (Japan)

2016-11-01

Highlights: • Precious metal catalyst based on cation-exchanged mordenite was prepared. • Isotope exchange reaction between H{sub 2} and HTO on the catalyst was investigated. • The order of entire reaction is not clear, but it is the first-order reaction as for HTO. • Effect of exchanged cation may appear as the difference of the surface area of catalyst. - Abstract: It is known that the chemical forms of tritium released from a ceramic breeder blanket are hydrogen form and water form. To recover tritiated water vapor, adoption of dryer that is packed column of synthetic zeolite has been proposed. On the other hand, synthetic zeolite is often used as a support of precious metal catalyst. Such catalysts usually have a capability of hydrogen isotope exchange between gas and water vapor. If this catalyst is used to dryer, the dryer may obtain a preferable function for tritium recovery by isotopic exchange reaction. To assess such functions, reaction rate should be estimated. The results of water adsorption experiment on cation-exchanged mordenite-type zeolite suggested the possibility that state of adsorbed water varied by exchanged cation. So, in this work, precious metal catalyst based on cation-exchanged mordenite was prepared, and the reaction rate of chemical exchange between hydrogen and tritiated water was investigated under temperature range between 30 °C and 80 °C by the steady-state approximation. In the case of platinum on Na-mordenite, the reaction between gaseous hydrogen and tritiated water vapor was almost expressed as first-order reaction concerning tritiated water vapor concentration.

Nanodiamond for tuning the properties of energetic composites

International Nuclear Information System (INIS)

Pichot, Vincent; Comet, Marc; Miesch, Julien; Spitzer, Denis

2015-01-01

Highlights: • Bismuth oxide (Bi 2 O 3 ) particles were successfully coated by detonation nanodiamond (DND). • Small DND contents strongly desensitize the Bi 2 O 3 /Al nanothermites to friction. • DNDs limit the electrostatic discharge sensitivity of the Bi 2 O 3 /Al nanothermites. • Desensitization can be mainly explained by the barrier role of the nanodiamonds. • Nanothermites sensitivity levels and flame propagation velocities are tuned by DND content. - Abstract: Bismuth oxide (Bi 2 O 3 ) particles were coated by detonation nanodiamonds. The resulting nanocomposite materials were mixed with an aluminum nanopowder (≈100 nm) to prepare nanothermites, with reduced sensitivity to friction and electrostatic discharge (ESD). The use of nanodiamond for this purpose is reported here for the first time. Their numerous qualities such as their small size, antifriction properties and thermal conductivity make them ideal candidates. Small amounts of detonation nanodiamonds allow obtaining impressive desensitization, making thus modified Bi 2 O 3 /Al nanothermite safe to handle. A composition containing around 1 wt.% of nanodiamond has a sensitivity threshold to friction superior to 100 N instead of 5 N for the thermite without nanodiamond. Furthermore, the sensitivity threshold to electrostatic discharge increases to 20 times when the nanodiamond content reaches 1.8 wt.%. The antifriction properties of nanodiamond limit the scratching of Bi 2 O 3 surface by Al particles. The desensitization to ESD is observed for a sufficient coverage of the oxide particles (1.8 wt.% of ND), which restrains the effect of the melt dispersion mechanism of aluminum and prevents the mixing of the oxidizing and the reducing parts of the composites. A good reactivity of the thermite could be maintained for nanodiamond content up to 2.6 wt.%. The carburizing of aluminum coming on contact with nanodiamond during the thermite reaction could be evidenced by X-ray Diffraction and

Women's Experiences of Social Reactions From Informal and Formal Supports: Using a Modified Administration of the Social Reactions Questionnaire.

Science.gov (United States)

DePrince, Anne P; Dmitrieva, Julia; Gagnon, Kerry L; Srinivas, Tejaswinhi

2017-11-01

A growing literature links social reactions to disclosures of intimate violence to posttraumatic outcomes. The Social Reactions Questionnaire (SRQ), a widely used measure developed to assess social reactions, asks about reactions received from people generally. The ability to examine the impact of social reactions from specific groups of people-such as criminal justice personnel versus community-based providers-has become increasingly more important from both research and practice perspectives. For example, as sexual assault responses nationally have relied on community-coordinated models that involve both criminal justice and community-based systems, tools are lacking to systematically assess the impact of social reactions from criminal justice personnel and community-based providers on survivors. Using the SRQ, the current study asked women to report separately on reactions received from criminal justice personnel, community-based providers, and informal supports. We recruited a diverse community sample of women ( N = 228, ages 18-63, 19% lesbian/bisexual, 44% ethnic minority) who experienced a sexual assault in the previous year and disclosed to the criminal justice system and/or a community-based provider. Multilevel analyses revealed considerable variability in the social reactions reported by women across criminal justice personnel, community-based providers, and informal supports. Analyses supported a seven-factor structure for the SRQ when the measure is yoked to particular experiences of disclosure, in this case to criminal justice personnel, community-based providers, or informal supports. The utility of this modified administration and scoring of the SRQ and the importance of considering reactions across different groups are described.

Modification of Oil Palm Mesocarp Fiber Characteristics Using Superheated Steam Treatment

Directory of Open Access Journals (Sweden)

Subbian Karuppuchamy

2013-07-01

Full Text Available In this study, oil palm mesocarp fiber (OPMF was treated with superheated steam (SHS in order to modify its characteristics for biocomposite applications. Treatment was conducted at temperatures 190–230 °C for 1, 2 and 3 h. SHS-treated OPMF was evaluated for its chemical composition, thermal stability, morphology and crystallinity. OPMF treated at 230 °C exhibited lower hemicellulose content (9% compared to the untreated OPMF (33%. Improved thermal stability of OPMF was found after the SHS treatment. Moreover, SEM and ICP analyses of SHS-treated OPMF showed that silica bodies were removed from OPMF after the SHS treatment. XRD results exhibited that OPMF crystallinity increased after SHS treatment, indicating tougher fiber properties. Hemicellulose removal makes the fiber surface more hydrophobic, whereby silica removal increases the surface roughness of the fiber. Overall, the results obtained herewith suggested that SHS is an effective treatment method for surface modification and subsequently improving the characteristics of the natural fiber. Most importantly, the use of novel, eco-friendly SHS may contribute to the green and sustainable treatment for surface modification of natural fiber.

Secondhand Smoke Exposure Among Nonsmoking Adolescents in West Africa

Science.gov (United States)

Veeranki, Sreenivas P.; Kioko, David M.; Ogwell Ouma, Ahmed E.

2015-01-01

Objectives. We estimated the prevalence and determinants of secondhand smoke (SHS) exposure among nonsmoking adolescents in 9 West African countries. Methods. We conducted a pooled analysis with nationally representative 2006 to 2009 Global Youth Tobacco Survey data. We used descriptive statistics to determine the prevalence of SHS exposure and inferential statistics using a multivariable logistic regression model to determine factors associated with SHS exposure. We investigated average marginal effect results that show the probability of SHS exposure, adjusting for all other attributes. Results. SHS exposure inside the home ranged from 13.0% to 45.0%; SHS exposure outside the home ranged from 24.7% to 80.1%. Parental or peer smoking behaviors were significantly associated with higher probability of SHS exposure in all 9 countries. Knowledge of smoking harm, support for smoking bans, exposure to antismoking media messages, and receptivity of school tobacco education were significantly associated with higher SHS exposure in most countries. Conclusions. West African policymakers should adopt policies consistent with Article 8 of the World Health Organization Framework Convention on Tobacco Control and its guidelines and public health education to promote smoke-free households. PMID:26180960

Simulationsexperimente zum Ausbreitungsverhalten von Kernschmelzen: KATS-8 bis KATS-17

International Nuclear Information System (INIS)

Eppinger, B; Fieg, G.; Massier, H.; Schuetz, W.; Stegmaier, U.; Stern, G.

2001-03-01

In future Light Water Reactors special devices (core catchers) might be required to prevent containment failure by basement erosion after reactor pressure vessel meltthrough during a core meltdown accident. Quick freezing of the molten core masses is desirable to reduce release of radioactivity. Several concepts of core catcher devices have been proposed based on the spreading of corium melt onto flat surfaces with subsequent water cooling. Therefore, a series of experiments to investigate high temperature melt spreading on flat surfaces has been carried out using alumina-iron thermite melts as a simulant. The oxidic thermite melt is conditioned by adding other oxides to simulate a realistic corium melt as close as possible. Spreading of oxidic and metallic melts have been performed in one- and two-dimensional geometry. Substrates were inert ceramical layer, dry concrete and concrete with a water layer of several millimeters. The influence of a shallow water layer on the surface onto the spreading behaviour has also been studied. (orig.) [de

Simulation experiment on the flooding behaviour of core melts: KATS-9

International Nuclear Information System (INIS)

Fieg, G.; Massier, H.; Schuetz, W.; Stegmaier, U.; Stern, G.

2000-11-01

For future Light Water Reactors special devices (core catchers) are being developed to prevent containment failure by basement erosion after reactor pressure vessel meltthrough during a core meltdown accident. Quick freezing of the molten core masses is desirable to reduce release of radioactivity. Several concepts of core catcher devices have been proposed based on the spreading of corium melt onto flat surfaces with subsequent water cooling. A KATS-experiment has been performed to investigate the flooding behaviour of high temperature melts using alumina-iron thermite melts as a simulant. The oxidic thermite melt is conditioned by adding other oxides to simulate a realistic corium melt as close as possible in terms of liquidus and solidus temperatures. Before flooding with water, spreading of the separate oxidic and metallic melts has been done in one-dimensional channels with a silicate concrete as the substrate. The flooding rate was, in relation to the melt surface, identical to the flooding rate in EPR. (orig.) [de

Late adverse reactions to intravascular iodine based contrast media

DEFF Research Database (Denmark)

Bellin, Marie-France; Stacul, Fulvio; Webb, Judith A W

2011-01-01

DEFINITION: Late adverse reactions (LAR) to contrast media (CM) are defined as reactions occurring 1 h to 1 week after exposure. NEED FOR REVIEW: In view of more prospective studies of LAR and new data about their pathophysiology, the Contrast Medium Safety Committee (CMSC) of the European Societ...

Characterization of reaction conditions providing rapid and specific cysteine alkylation for peptide-based mass spectrometry.

Science.gov (United States)

Paulech, Jana; Solis, Nestor; Cordwell, Stuart J

2013-01-01

Alkylation converts Cys thiols to thioethers and prevents unwanted side reactions, thus facilitating mass spectrometric identification of Cys-containing peptides. Alkylation occurs preferentially at Cys due to its high nucleophilicity, however reactions at other such sites are possible. N-ethylmaleimide (NEM) shows rapid reaction kinetics with Cys and careful definition of reaction conditions results in little reactivity at other sites. Analysis of a protein standard alkylated under differing reaction conditions (pH, NEM concentrations and reaction times) was performed using liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) and selected reaction monitoring (SRM) of NEM-modified and unmodified peptide pairs. Mis-alkylation sites at primary and secondary amines were identified and limited to one equivalent of NEM. No evidence for hydroxyl or thioether alkylation was observed. Improved specificity was achieved by restricting the pH below neutral, NEM concentration below 10mM and/or reaction time to below 5min. Maximal removal of Cys activity was observed in tissue homogenates at 40mM NEM within 1min, dependent upon efficient protein denaturation. SRM assays identified peptide-specific levels of mis-alkylation, indicating that NEM-modified to unmodified ratios did not exceed 10%, with the exception of Cys alkylation that proceeded to 100%, and some Lys residues that resulted in tryptic missed cleavages. High reactivity was observed for His residues considering their relatively low abundance. These data indicate that rapid and specific Cys alkylation is possible with NEM under relatively mild conditions, with more abrasive conditions leading to increased non-specific alkylation without appreciable benefit for MS-based proteomics. Copyright © 2012 Elsevier B.V. All rights reserved.

Secondhand smoke exposure among Hispanics/Latinos living in multiunit housing: exploring barriers to new policies.

Science.gov (United States)

Baezconde-Garbanati, Lourdes A; Weich-Reushé, Kimberly; Espinoza, Lilia; Portugal, Cecilia; Barahona, Rosa; Garbanati, James; Seedat, Faatima; Unger, Jennifer B

2011-01-01

Despite a high prevalence of voluntary home smoking bans and laws protecting Californians from exposure to secondhand smoke (SHS) in the workplace, many Hispanic/Latino (H/L) residents of multiunit housing (MUH) are potentially exposed to SHS from neighboring apartments. An advocacy/policy intervention was implemented to reduce tobacco-related health disparities by encouraging H/L living in MUH to implement voluntary policies that reduce exposure to SHS. This article presents findings from qualitative and quantitative data collected during development of the intervention, as well as preliminary results of the intervention. MUH residents in Southern California participated in focus groups (n = 48), door-to-door surveys (n = 142), and a telephone survey (n = 409). Exposure to SHS, attitudes toward SHS, and attitudes toward policies restricting SHS in MUH were assessed. H/L MUH residents reported high levels of exposure to SHS and little ability to protect themselves and their families from SHS. Respondents expressed positive attitudes toward adopting antismoking policies in MUH, but they also feared retaliation by smokers. The cultural values of familismo, respeto, simpatía, and personalismo influenced their motivation to protect their families from SHS as well as their reluctance to ask their neighbors to refrain from smoking. Nonsmokers were more likely to favor complete indoor and outdoor smoking bans in MUH, whereas smokers were more likely to favor separate smoking areas. The Regale Salud advocacy/policy intervention, implemented to reduce SHS exposure, prompted the passage of seven voluntary policies in apartment complexes in Southern California to prevent smoking in MUH. H/L in California support voluntary policies, local ordinances, and state laws that prevent exposure to SHS in MUH, especially those that are consistent with H/L cultural values and norms for interpersonal communication.

Socioeconomic disparities in secondhand smoke exposure among US never-smoking adults: the National Health and Nutrition Examination Survey 1988-2010.

Science.gov (United States)

Gan, Wen Qi; Mannino, David M; Jemal, Ahmedin

2015-11-01

Secondhand smoke (SHS) is a leading preventable cause of illness, disability and mortality. There is a lack of quantitative analyses on socioeconomic disparities in SHS; especially, it is not known how socioeconomic disparities have changed in the past two decades in the USA. To examine socioeconomic disparities and long-term temporal trends in SHS exposure among US never-smoking adults aged ≥20 years. 15 376 participants from the National Health and Nutrition Examination Survey (NHANES) 1999-2010 were included in the analysis of socioeconomic disparities; additional 8195 participants from NHANES III 1988-1994 were included in the temporal trend analysis. SHS exposure was assessed using self-reported exposure in the home and workplace as well as using serum cotinine concentrations ≥0.05 ng/mL. Individual socioeconomic status (SES) was assessed using poverty-to-income ratio. During the period 1999-2010, 6% and 14% of participants reported SHS exposure in the home and workplace, respectively; 40% had serum cotinine-indicated SHS exposure. Individual SES was strongly associated with SHS exposure in a dose-response fashion; participants in the lowest SES group were 2-3 times more likely to be exposed to SHS compared with those in the highest SES group. During the period 1988-2010, the prevalence declined over 60% for the three types of SHS exposure. However, for cotinine-indicated exposure, the magnitudes of the declines were smaller for lower SES groups compared with higher SES groups, leading to widening socioeconomic disparities in SHS exposure. SHS exposure is still widespread among US never-smoking adults, and socioeconomic disparities for cotinine-indicated exposure have substantially increased in the past two decades. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Synthesis of ferrofluids based on cobalt ferrite nanoparticles: Influence of reaction time on structural, morphological and magnetic properties

Energy Technology Data Exchange (ETDEWEB)

Amirabadizadeh, Ahmad; Salighe, Zohre; Sarhaddi, Reza, E-mail: reza.sarhaddi@birjand.ac.ir; Lotfollahi, Zahra

2017-07-15

Highlights: • Ferrofluids based on cobalt ferrite nanoparticles were synthesized by co-precipitation method. • The crystallite and particle size of cobalt ferrite can be controlled effectively by reaction time. • The ferrofluids have lower values of saturation magnetization and coercivity as compared to nanoparticles. • By increasing the size of nanoparticles, the narrower and sharper spikes of ferrofluids are formed. - Abstract: In this work, for first time the ferrofluids based on the cobalt ferrite (CoFe{sub 2}O{sub 4}) nanoparticles were prepared by the co-precipitation method at different reaction times (0.5–6.5 h). Crystal structure, morphology and magnetic properties of the cobalt ferrite nanoparticles and the ferrofluids based on the nanoparticles were studied by X-ray diffraction (XRD), field emission scanning electron microscope (FESEM) and vibrating sample magnetometer (VSM). The XRD patterns of CoFe{sub 2}O{sub 4} nanoparticles synthesized at different reaction times indicated that all samples are single phase in accordance with inverse cubic spinel structure with space group Fd-3m, and no impurity phase was observed. By increasing the reaction time to 3.5 h, the lattice parameter and the average crystallites size increased and then afterwards decreased by increasing the reaction time. The microscopic studies indicated the formation of nanosized particles with nearly spherical in shape, whereas the average particle size for all samples is found to be less than 50 nm. The results of VSM also showed that the saturation magnetization and coercivity field of the cobalt ferrite nanoparticles and the ferrofluids were influenced by reaction time, whereas the ferrofluids have lower values of magnetic parameters than that of nanoparticles.

Well-defined Polymethylene-Based Co/Terpolymers by Combining Anthracene/Maleimide Diels-Alder Reaction with Polyhomologation

KAUST Repository

Hadjichristidis, Nikolaos; Alkayal, Nazeeha

2015-01-01

A novel strategy towards well-defined polymethylene-based co/terpolymers, by combining anthracene/maleimide Diels-Alder reaction with polyhomologation, is presented. For the synthesis of diblock copolymers the following approach was applied: a

The impact of smoke-free legislation on reducing exposure to secondhand smoke: differences across gender and socioeconomic groups.

Science.gov (United States)

Tsai, Yi-Wen; Chang, Li-Chuan; Sung, Hai-Yen; Hu, Teh-Wei; Chiou, Shu-Ti

2015-01-01

On 11 January 2009, Taiwan expanded its smoke-free legislation to all indoor public places and workplaces. This study examined the impact of this policy on secondhand smoke (SHS) exposure in adult non-smokers, across gender and socioeconomic status groups (SES). An annual sample of about 13,000-14,000 non-smokers was drawn from cross-sectional nationwide data of Taiwan Adult Tobacco Behavior Surveys during 2005-2011. Logistic regressions were used to analyse the aggregate data to estimate the association between the 2009 smoke-free legislation and SHS exposures in homes and workplaces. Interaction terms were used to examine the impact of the 2009 smoke-free policy on reducing differences in SHS exposure across gender, education and income groups. The 2009 policy reduced the odds of SHS exposure in homes in 2009 (OR=0.76, 95% CI 0.68 to 0.84) and in workplaces (year 2009: OR=0.49, 95% CI 0.39 to 0.62; year 2010: OR=0.79, 95% CI 0.66 to 0.95). The model with interaction terms showed that men were more likely than women to be exposed to workplace SHS (OR=2.02, 95% CI 1.80 to 2.27) but were less likely to be exposed to home SHS (OR=0.79, 95% CI 0.73 to 0.86). SHS exposure in homes was significantly related to lower socioeconomic status, but the 2009 smoke-free policy reduced the difference in SHS exposure across education levels. The 2009 smoke-free policy reduced the SHS exposure for non-smokers. However, this impact on home SHS did not persist after 2009, and the effect of protection was unequal across gender and SES groups. Thus, further enforcement of smoking restrictions would be needed to reduce the risk of SHS exposure and improve protection against SHS risk among parts of the population with lower socioeconomic status. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Employment Condition, Economic Deprivation and Self-Evaluated Health in Europe: Evidence from EU-SILC 2009–2012

Science.gov (United States)

Bacci, Silvia; Pigini, Claudia; Seracini, Marco; Minelli, Liliana

2017-01-01

Background: The mixed empirical evidence about employment conditions (i.e., permanent vs. temporary job, full-time vs. part-time job) as well as unemployment has motivated the development of conceptual models with the aim of assessing the pathways leading to effects of employment status on health. Alongside physically and psychologically riskier working conditions, one channel stems in the possibly severe economic deprivation faced by temporary workers. We investigate whether economic deprivation is able to partly capture the effect of employment status on Self-evaluated Health Status (SHS). Methods: Our analysis is based on the European Union Statistics on Income and Living Conditions (EU-SILC) survey, for a balanced sample from 26 countries from 2009 to 2012. We estimate a correlated random-effects logit model for the SHS that accounts for the ordered nature of the dependent variable and the longitudinal structure of the data. Results and Discussion: Material deprivation and economic strain are able to partly account for the negative effects on SHS from precarious and part-time employment as well as from unemployment that, however, exhibits a significant independent negative association with SHS. Conclusions: Some of the indicators used to proxy economic deprivation are significant predictors of SHS and their correlation with the employment condition is such that it should not be neglected in empirical analysis, when available and further to the monetary income. PMID:28165375

Employment Condition, Economic Deprivation and Self-Evaluated Health in Europe: Evidence from EU-SILC 2009-2012.

Science.gov (United States)

Bacci, Silvia; Pigini, Claudia; Seracini, Marco; Minelli, Liliana

2017-02-03

Background : The mixed empirical evidence about employment conditions (i.e., permanent vs. temporary job, full-time vs. part-time job) as well as unemployment has motivated the development of conceptual models with the aim of assessing the pathways leading to effects of employment status on health. Alongside physically and psychologically riskier working conditions, one channel stems in the possibly severe economic deprivation faced by temporary workers. We investigate whether economic deprivation is able to partly capture the effect of employment status on Self-evaluated Health Status (SHS). Methods : Our analysis is based on the European Union Statistics on Income and Living Conditions (EU-SILC) survey, for a balanced sample from 26 countries from 2009 to 2012. We estimate a correlated random-effects logit model for the SHS that accounts for the ordered nature of the dependent variable and the longitudinal structure of the data. Results and Discussion : Material deprivation and economic strain are able to partly account for the negative effects on SHS from precarious and part-time employment as well as from unemployment that, however, exhibits a significant independent negative association with SHS. Conclusions : Some of the indicators used to proxy economic deprivation are significant predictors of SHS and their correlation with the employment condition is such that it should not be neglected in empirical analysis, when available and further to the monetary income.

Solution phase and membrane immobilized iron-based free radical reactions: Fundamentals and applications for water treatment

Science.gov (United States)

Lewis, Scott Romak

Membrane-based separation processes have been used extensively for drinking water purification, wastewater treatment, and numerous other applications. Reactive membranes synthesized through functionalization of the membrane pores offer enhanced reactivity due to increased surface area at the polymer-solution interface and low diffusion limitations. Oxidative techniques utilizing free radicals have proven effective for both the destruction of toxic organics and non-environmental applications. Most previous work focuses on reactions in the homogeneous phase; however, the immobilization of reactants in membrane pores offers several advantages. The use of polyanions immobilized in a membrane or chelates in solution prevents ferric hydroxide precipitation at near-neutral pH, a common limitation of iron(Fe(II/III))-catalyzed hydrogen peroxide (H 2O2) decomposition. The objectives of this research are to develop a membrane-based platform for the generation of free radicals, degrade toxic organic compounds using this and similar solution-based reactions, degrade toxic organic compounds in droplet form, quantify hydroxyl radical production in these reactions, and develop kinetic models for both processes. In this study, a functionalized membrane containing poly(acrylic acid) (PAA) was used to immobilize iron ions and conduct free radical reactions by permeating H2O2 through the membrane. The membrane's responsive behavior to pH and divalent cations was investigated and modeled. The conversion of Fe(II) to Fe(III) in the membrane and its effect on the decomposition of hydrogen peroxide were monitored and used to develop kinetic models for predicting H2O2 decomposition in these systems. The rate of hydroxyl radical production, and hence contaminant degradation can be varied by changing the residence time, H2O2 concentration, and/or iron loading. Using these membrane-immobilized systems, successful removal of toxic organic compounds, such as pentachlorophenol (PCP), from water

Effectiveness of a smoke-free policy in lowering secondhand smoke concentrations in offices in China.

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Gan, Quan; Hammond, S Katharine; Jiang, Yuan; Yang, Yan; Hu, Teh-Wei

2008-05-01

To examine the secondhand smoke (SHS) exposure level in Chinese office buildings and to evaluate the effectiveness of a smoke-free policy in reducing SHS exposure. Survey of smoking policies and measurement of SHS level in 14 office buildings from 10 provinces in China. Smoking in the building significantly elevated the SHS concentrations both in offices with at least one smoker and in offices with no smokers. In one building that recently adopted a smoke-free policy, the nicotine concentrations decreased significantly after the policy was enacted. Enactment of a smoking policy was effective in reducing SHS exposure in the buildings. Nonsmoking office workers in China were exposed to significant levels of SHS at work; both the central and local governments should realize the need to legislate against workplace smoking.

Contactless, probeless and non-titrimetric determination of acid-base reactions using broadband acoustic resonance dissolution spectroscopy (BARDS).

Science.gov (United States)

Ahmed, M Rizwan; McSweeney, Sean; Krüse, Jacob; Vos, Bastiaan; Fitzpatrick, Dara

2018-02-12

pH determination is a routine measurement in scientific laboratories worldwide. Most major advances in pH measurement were made in the 19th and early 20th century. pH measurements are critical for the determination of acid base reactions. This study demonstrates how an acid-base reaction can be monitored without the use of a pH probe, indicator and titres of reagent. The stoichiometric reaction between carbonate and HCl acid yields specific quantities of CO 2 , which causes reproducible changes to the compressibility of the solvent. This in turn slows down the speed of sound in solution which is induced by a magnetic follower gently tapping the inner wall of the vessel. As a consequence the frequencies of the acoustic resonances in the vessel are reduced. This approach is called Broadband Acoustic Resonance Dissolution Spectroscopy (BARDS) which harnesses this phenomenon for many applications. The acid-carbonate experiments have also been validated using H 2 SO 4 acid and using both potassium and sodium counterions for the carbonate. This method can be used to interrogate strong acid-base reactions in a rapid and non-invasive manner using carbonate as the base. The data demonstrate the first example of a reactant also acting as an indicator. The applicability of the method to weak acids has yet to be determined. A novel conclusion from the study is that a person with a well-trained ear is capable of determining the concentration and pH of a strong acid just by listening. This brings pH measurement into the realm of human perception.

Reaction energetics on long-range corrected density functional theory: Diels-Alder reactions.

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Singh, Raman K; Tsuneda, Takao

2013-02-15

The possibility of quantitative reaction analysis on the orbital energies of long-range corrected density functional theory (LC-DFT) is presented. First, we calculated the Diels-Alder reaction enthalpies that have been poorly given by conventional functionals including B3LYP functional. As a result, it is found that the long-range correction drastically improves the reaction enthalpies. The barrier height energies were also computed for these reactions. Consequently, we found that dispersion correlation correction is also crucial to give accurate barrier height energies. It is, therefore, concluded that both long-range exchange interactions and dispersion correlations are essentially required in conventional functionals to investigate Diels-Alder reactions quantitatively. After confirming that LC-DFT accurately reproduces the orbital energies of the reactant and product molecules of the Diels-Alder reactions, the global hardness responses, the halves of highest occupied molecular orbital (HOMO)-lowest unoccupied molecular orbital (LUMO) energy gaps, along the intrinsic reaction coordinates of two Diels-Alder reactions were computed. We noticed that LC-DFT results satisfy the maximum hardness rule for overall reaction paths while conventional functionals violate this rule on the reaction pathways. Furthermore, our results also show that the HOMO-LUMO gap variations are close to the reaction enthalpies for these Diels-Alder reactions. Based on these results, we foresee quantitative reaction analysis on the orbital energies. Copyright © 2012 Wiley Periodicals, Inc.

Adverse allergic reactions to linear ionic gadolinium-based contrast agents: experience with 194, 400 injections

International Nuclear Information System (INIS)

Aran, S.; Shaqdan, K.W.; Abujudeh, H.H.

2015-01-01

Aim: To report the authors' experience with the administration of four gadolinium-based contrast agents (GBCA; gadopentetate dimeglumine, gadofosveset trisodium, gadoxetate disodium and gadobenate dimeglumine) in a large study population at a single, large academic medical centre. Materials and methods: The institutional review board approved this retrospective study in which data in the electronic incident reporting system were searched. A total of 194, 400 intravenous administrations of linear ionic GBCAs were assessed for the incidence of adverse reactions and risk factors from 1 January 2007 to 14 January 2014. The severity of reactions (mild, moderate, and severe), patient type (outpatients, inpatients, and emergency), examination type, and treatment options were also investigated. Results: In total, 204/194400 (0.1%) patients (mean age 45.7 ± 14.9) showed adverse reactions, consisting of 6/746 (0.80%), 10/3200 (0.31%), 14/6236 (0.22%) and 174/184218 (0.09%), for gadofosveset trisodium, gadoxetate disodium, gadobenate dimeglumine, and gadopentetate dimeglumine, respectively. An overall significant difference was found between different GBCAs regarding the total number of reactions (p < 0.0001). When comparing the GBCAs together, significant differences were found between gadofosveset trisodium versus gadopentetate dimeglumine (p < 0.0001), gadofosveset trisodium versus gadobenate dimeglumine (p = 0.0051), gadoxetate disodium versus gadopentetate dimeglumine (p < 0.0001) and gadopentetate dimeglumine versus gadobenate dimeglumine (p = 0.0013). Rate of reaction was higher in females (F: 146/113187, 0.13%/M: 58/81213, 0.07%; p < 0.0001). Rate of reactions was higher in outpatient (180/158885, 0.11%), emergency (10/10413, 0.10%), and inpatients (14/25102, 0.05%), respectively (p < 0.0001). Most of the patients had mild symptoms 171/204 (83.8%). Abdomen–pelvis, liver, and thoracic examinations had highest rates of reactions (0.17 versus 0

Lab Scale Study of the Depletion of Mullite/Corundum-Based Refractories Trough Reaction with Scaffold Materials

International Nuclear Information System (INIS)

Stjernberg, J; Antti, M-L; Ion, J C; Lindblom, B

2011-01-01

To investigate the mechanisms underlying the depletion of mullite/corundum-based refractory bricks used in rotary kilns for iron ore pellet production, the reaction mechanisms between scaffold material and refractory bricks have been studied on the laboratory-scale. Alkali additions were used to enhance the reaction rates between the materials. The morphological changes and active chemical reactions at the refractory/scaffold material interface in the samples were characterized using scanning electron microscopy (SEM), thermal analysis (TA) and X-ray diffraction (XRD). No reaction products of alkali and hematite (Fe 2 O 3 ) were detected; however, alkali dissolves the mullite in the bricks. Phases such as nepheline (Na 2 O·Al 2 O 3 ·2SiO 2 ), kalsilite (K 2 O·Al 2 O 3 ·2SiO 2 ), leucite (K 2 O·Al 2 O 3 ·4SiO 2 ) and potassium β-alumina (K 2 O·11Al 2 O 3 ) were formed as a consequence of reactions between alkali and the bricks.

Nuclear Astrophysics and Neutron Induced Reactions: Quasi-Free Reactions and RIBs

International Nuclear Information System (INIS)

Cherubini, S.; Spitaleri, C.; Crucilla, V.; Gulino, M.; La Cognata, M.; Lamia, L.; Pizzone, R. G.; Puglia, S.; Rapisarda, G. G.; Romano, S.; Sergi, M. L.; Coc, A.; Kubono, S.; Binh, D. N.; Hayakawa, S.; Wakabayashi, Y.; Yamaguchi, H.; Burjan, V.; Kroha, V.; De Sereville, N.

2010-01-01

The use of quasi-free reactions in studying nuclear reactions between charged particles of astrophysical interest has received much attention over the last two decades. The Trojan Horse Method is based on this approach and it has been used to study a number of reactions relevant for Nuclear Astrophysics. Recently we applied this method to the study of nuclear reactions that involve radioactive species, namely to the study of the 18 F+p→ 15 O+α process at temperatures corresponding to the energies available in the classical novae scenario. Quasi-free reactions can also be exploited to study processes induced by neutrons. This technique is particularly interesting when applied to reaction induced by neutrons on unstable short-lived nuclei. Such processes are very important in the nucleosynthesis of elements in the sand r-processes scenarios and this technique can give hints for solving key questions in nuclear astrophysics where direct measurements are practically impossible.

Organocatalytic aza-Michael/retro-aza-Michael reaction: pronounced chirality amplification in aza-Michael reaction and racemization via retro-aza-Michael reaction.

Science.gov (United States)

Cai, Yong-Feng; Li, Li; Luo, Meng-Xian; Yang, Ke-Fang; Lai, Guo-Qiao; Jiang, Jian-Xiong; Xu, Li-Wen

2011-05-01

A detailed experimental investigation of an aza-Michael reaction of aniline and chalcone is presented. A series of Cinchona alkaloid-derived organocatalysts with different functional groups were prepared and used in the aza-Michael and retro-aza-Michael reaction. There was an interesting finding that a complete reversal of stereoselectivity when a benzoyl group was introduced to the cinchonine and cinchonidine. The chirality amplification vs. time proceeds in the quinine-derived organocatalyst containing silicon-based bulky group, QN-TBS, -catalyzed aza-Michael reaction under solvent-free conditions. In addition, we have demonstrated for the first time that racemization was occurred in suitable solvents under mild conditions due to retro-aza-Michael reaction of the Michael adduct of aniline with chalcone. These indicate the equilibrium of retro-aza-Michael reaction and aza-Michael reaction produce the happening of chirality amplification in aza-Michael reaction and racemization via retro-aza-Michael reaction under different conditions, which would be beneficial to the development of novel chiral catalysts for the aza-Michael reactions. Copyright © 2011 Wiley-Liss, Inc.

Verification of dosimetry cross sections above 10 MeV based on measurement of activation reaction rates in fission neutron field

International Nuclear Information System (INIS)

Odano, Naoteru; Miura, Toshimasa; Yamaji, Akio.

1996-01-01

To validate the dosimetry cross sections in fast neutron energy range, activation reaction rates were measured for 5 types of dosimetry cross sections which have sensitivity in the energy rage above 10 MeV utilizing JRR-4 reactor of JAERI. The measured reaction rates were compared with the calculations reaction rates by a continuous energy monte carlo code MVP. The calculated reaction rates were based on two dosimetry files, JENDL Dosimetry File and IRDF-90.2. (author)

Tunable Reflective Spatial Heterodyne Spectrometer: A Technique for High Resolving Power, Wide Field Of View Observation Of Diffuse Emission Line Sources

Science.gov (United States)

Hosseini, Seyedeh Sona

The purpose of this dissertation is to discuss the need for new technology in broadband high-resolution spectroscopy based on the emerging technique of Spatial Heterodyne Spectroscopy (SHS) and to propose new solutions that should enhance and generalize this technology to other fields. Spectroscopy is a proven tool for determining compositional and other properties of remote objects. Narrow band imaging and low resolving spectroscopic measurements provide information about composition, photochemical evolution, energy distribution and density. The extension to high resolving power provides further access to temperature, velocity, isotopic ratios, separation of blended sources, and opacity effects. In current high resolving power devices, the drawback of high-resolution spectroscopy is bound to the instrumental limitations of lower throughput, the necessity of small entrance apertures, sensitivity, field of view, and large physical instrumental size. These limitations quickly become handicapping for observation of faint and/or extended targets and for spacecraft encounters. A technique with promise for the study of faint and extended sources at high resolving power is the reflective format of the Spatial Heterodyne Spectrometer (SHS). SHS instruments are compact and naturally tailored for both high etendue (defined in section 2.2.5) and high resolving power. In contrast, to achieve similar spectral grasp, grating spectrometers require large telescopes. For reference, SHS is a cyclical interferometer that produces Fizeau fringe pattern for all other wavelengths except the tuned wavelength. The large etendue obtained by SHS instruments makes them ideal for observations of extended, low surface brightness, isolated emission line sources, while their intrinsically high spectral resolution enables one to study the dynamical and physical properties described above. This document contains four chapters. Chapter 1, introduces a class of scientific targets that formerly have

Effect of a perturbation-based balance training program on compensatory stepping and grasping reactions in older adults: a randomized controlled trial.

Science.gov (United States)

Mansfield, Avril; Peters, Amy L; Liu, Barbara A; Maki, Brian E

2010-04-01

Compensatory stepping and grasping reactions are prevalent responses to sudden loss of balance and play a critical role in preventing falls. The ability to execute these reactions effectively is impaired in older adults. The purpose of this study was to evaluate a perturbation-based balance training program designed to target specific age-related impairments in compensatory stepping and grasping balance recovery reactions. This was a double-blind randomized controlled trial. The study was conducted at research laboratories in a large urban hospital. Thirty community-dwelling older adults (aged 64-80 years) with a recent history of falls or self-reported instability participated in the study. Participants were randomly assigned to receive either a 6-week perturbation-based (motion platform) balance training program or a 6-week control program involving flexibility and relaxation training. Features of balance reactions targeted by the perturbation-based program were: (1) multi-step reactions, (2) extra lateral steps following anteroposterior perturbations, (3) foot collisions following lateral perturbations, and (4) time to complete grasping reactions. The reactions were evoked during testing by highly unpredictable surface translation and cable pull perturbations, both of which differed from the perturbations used during training. /b> Compared with the control program, the perturbation-based training led to greater reductions in frequency of multi-step reactions and foot collisions that were statistically significant for surface translations but not cable pulls. The perturbation group also showed significantly greater reduction in handrail contact time compared with the control group for cable pulls and a possible trend in this direction for surface translations. Further work is needed to determine whether a maintenance program is needed to retain the training benefits and to assess whether these benefits reduce fall risk in daily life. Perturbation-based training

Sleeve reaction chamber system

Science.gov (United States)

Northrup, M Allen [Berkeley, CA; Beeman, Barton V [San Mateo, CA; Benett, William J [Livermore, CA; Hadley, Dean R [Manteca, CA; Landre, Phoebe [Livermore, CA; Lehew, Stacy L [Livermore, CA; Krulevitch, Peter A [Pleasanton, CA

2009-08-25

A chemical reaction chamber system that combines devices such as doped polysilicon for heating, bulk silicon for convective cooling, and thermoelectric (TE) coolers to augment the heating and cooling rates of the reaction chamber or chambers. In addition the system includes non-silicon-based reaction chambers such as any high thermal conductivity material used in combination with a thermoelectric cooling mechanism (i.e., Peltier device). The heat contained in the thermally conductive part of the system can be used/reused to heat the device, thereby conserving energy and expediting the heating/cooling rates. The system combines a micromachined silicon reaction chamber, for example, with an additional module/device for augmented heating/cooling using the Peltier effect. This additional module is particularly useful in extreme environments (very hot or extremely cold) where augmented heating/cooling would be useful to speed up the thermal cycling rates. The chemical reaction chamber system has various applications for synthesis or processing of organic, inorganic, or biochemical reactions, including the polymerase chain reaction (PCR) and/or other DNA reactions, such as the ligase chain reaction.

Magnetic actuator for the control and mixing of magnetic bead-based reactions on-chip.

Science.gov (United States)

Berenguel-Alonso, Miguel; Granados, Xavier; Faraudo, Jordi; Alonso-Chamarro, Julián; Puyol, Mar

2014-10-01

While magnetic bead (MB)-based bioassays have been implemented in integrated devices, their handling on-chip is normally either not optimal--i.e. only trapping is achieved, with aggregation of the beads--or requires complex actuator systems. Herein, we describe a simple and low-cost magnetic actuator to trap and move MBs within a microfluidic chamber in order to enhance the mixing of a MB-based reaction. The magnetic actuator consists of a CD-shaped plastic unit with an arrangement of embedded magnets which, when rotating, generate the mixing. The magnetic actuator has been used to enhance the amplification reaction of an enzyme-linked fluorescence immunoassay to detect Escherichia coli O157:H7 whole cells, an enterohemorrhagic strain, which have caused several outbreaks in food and water samples. A 2.7-fold sensitivity enhancement was attained with a detection limit of 603 colony-forming units (CFU) /mL, when employing the magnetic actuator.

Investigating Ionic Effects Applied to Water Based Organocatalysed Aldol Reactions

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Joshua P. Delaney

2011-12-01

Full Text Available Saturated aqueous solutions of various common salts were examined for their effect on aqueous aldol reactions catalysted by a highly active C2-symmetric diprolinamide organocatalyst developed in our laboratory. With respect to the aldol reaction between cyclohexanone and 4-nitrobenzaldehyde, deionised water was always a superior medium to salt solutions though some correlation to increasing anion size and depression in enantiomeric excess could be observed. Additionally, the complete inhibition of catalyst activity observed when employing tap water could be alleviated by the inclusion of ethylenediaminetetraacetate (EDTA into the aqueous media prior to reaction initiation. Extension of these reaction conditions demonstrated that these ionic effects vary on a case-to-case basis depending on the ketone/aldehyde combination.

[Associations between health-promoting lifestyle and suboptimal health status in Guangdong: a cross sectional study].

Science.gov (United States)

Chen, Jie-Yu; Yang, Le-Bin; Jiang, Ping-Ping; Sun, Xiao-Min; Yu, Ke-Qiang; Li, Fei; Wu, Sheng-Wei; Ji, Yan-Zhao; Zhao, Xiao-Shan; Luo, Ren

2016-04-01

To investigate associations between health-promoting lifestyle and suboptimal health status (SHS) in the population of Guangdong province. A cross-sectional survey was conducted in a clustered sample of 24 159 individuals aged 12-80 years from 2012 to 2013. Health-promoting lifestyle was assessed via the Health-Promoting Lifestyle Profile (HPLP-II), and SHS was evaluated using the medical examination report and Sub-health Measurement Scale V1.0 (SHMS V1.0). Of the 24159 participants, subjects with SHS (46.0%) and disease status (35.2%) accounted for a much higher percentage than healthy subjects (18.8%). Regression analyses revealed a significant association between health status and healthy lifestyle (PUnhealthy lifestyle was an important risk factor for SHS and disease, especially the former. Compared with the participants with a healthy lifestyle (minimal exposure), after demographic adjustment, subjects with a 'poor' lifestyle (maximal exposure) were at a 43 times higher risk of developing SHS (OR: 42.825, 95% CI: 30.567-59.997), those with a general lifestyle were at a 21 times higher risk of SHS (OR: 21.072, 95%CI: 17.258-25.729), and those with a suboptimal lifestyle had a 4 times higher risk (OR: 4.085, 95%CI: 3.352-4.979). In the general population, the major risk factors for SHS included poor stress management, poor self-actualization, inactive exercise and poor interpersonal relationship. s Unhealthy lifestyles are significantly related to an increased risk of SHS. Intervention of unhealthy lifestyles, controlling the risk factors of SHS, and rigorous management of the time window of SHS are necessary to promote the heath status.

Secondhand smoke exposure in cars and rooms: trend comparisons among subpopulations of nonsmoking U.S. middle and high school students.

Science.gov (United States)

McIntire, Russell K; Macy, Jonathan T; Seo, Dong-Chul; Nelson, Ashlyn A; Kolbe, Lloyd J

2014-06-01

Young people in the United States are exposed to secondhand smoke (SHS) primarily in 2 settings: homes and cars. Recently, researchers reported that the prevalence of U.S students exposed to SHS in cars decreased from 2000 to 2009; however, comparisons of trends across school levels, gender, and racial/ethnic groups were not assessed. Moreover, no studies have examined trends of exposure to SHS in rooms. We used data from the 2000, 2002, 2004, 2006, and 2009 waves of the National Youth Tobacco Survey, a nationally representative cross-sectional survey of U.S. middle and high school students. For SHS in cars and rooms, we identified exposure trends among nonsmokers from 2000 to 2009 and compared trends across subpopulations with binary logistic regression. We identified significant downward linear trends in SHS in cars and rooms for nearly all measured subpopulations of nonsmoking students from 2000 to 2009. SHS exposure in cars and rooms declined at a significantly greater rate for males than for females. SHS exposure in cars declined at a significantly greater rate for non-Hispanic (NH) Blacks than for NH Whites. SHS exposure in rooms declined at a significantly greater rate for NH Whites than for Hispanics and Native Hawaiians/Pacific Islanders. Although prevalence of exposure to SHS in cars and rooms among nonsmoking U.S. middle and high school students has declined from 2000 to 2009, the rates of decline were not equal across genders and racial/ethnic groups. Identification of these differing rates of exposure can help the public health community advocate for interventions focused on reducing adolescent SHS exposure.

Children's exposure to second hand smoke at home: A cross-sectional study in Portugal

Directory of Open Access Journals (Sweden)

Paulo D. Vitória

2015-07-01

Full Text Available Second-hand tobacco smoke (SHS is a major indoor pollutant that causes serious health problems for all exposed, especially children. Children are often exposed to SHS at home, due to parental or other households’ or guests’ smoking. This study describes Portuguese children's exposure to SHS at home (total and by Portuguese main regions.In 2010/2011, a questionnaire was applied to a sample of Portuguese children in the 4th grade (N = 3187, mean age 9.05 ± 0.7 years, 51.1% male. Descriptive analysis, chi-square tests and crude odds ratios were performed.Of the participants, 62.9% of those with smoking parents and 19.2% of those with non-smoking parents were exposed to SHS at their home. Parental smoking varied significantly among regions and was significantly associated with children's exposure to SHS at home.Children's exposure to SHS at home was high, especially if their parents smoke. Children living in Lisbon Region presented the highest SHS exposure rate. The association of SHS exposure with geographic regions suggests the influence of social and contextual factors on smoking behaviour and on tobacco control effectiveness. Our findings highlight the need to effectively prevent children's SHS exposure at their home and to develop tailored tobacco control measures by region. Keywords: Tobacco smoke pollution, Child welfare, Smoking, Tobacco, Parent–child relations

Effect of Perinatal secondhand tobacco smoke exposure on in vivo and intrinsic airway structure/function in non-human primates

International Nuclear Information System (INIS)

Joad, Jesse P.; Kott, Kayleen S.; Bric, John M.; Peake, Janice L.; Pinkerton, Kent E.

2009-01-01

Infants exposed to second hand smoke (SHS) experience more problems with wheezing. This study was designed to determine if perinatal SHS exposure increases intrinsic and/or in vivo airway responsiveness to methacholine and whether potential structural/cellular alterations in the airway might explain the change in responsiveness. Pregnant rhesus monkeys were exposed to filtered air (FA) or SHS (1 mg/m 3 total suspended particulates) for 6 h/day, 5 days/week starting at 50 days gestational age. The mother/infant pairs continued the SHS exposures postnatally. At 3 months of age each infant: 1) had in vivo lung function measurements in response to inhaled methacholine, or 2) the right accessory lobe filled with agarose, precision-cut to 600 μm slices, and bathed in increasing concentrations of methacholine. The lumenal area of the central airway was determined using videomicrometry followed by fixation and histology with morphometry. In vivo tests showed that perinatal SHS increases baseline respiratory rate and decreases responsiveness to methacholine. Perinatal SHS did not alter intrinsic airway responsiveness in the bronchi. However in respiratory bronchioles, SHS exposure increased airway responsiveness at lower methacholine concentrations but decreased it at higher concentrations. Perinatal SHS did not change eosinophil profiles, epithelial volume, smooth muscle volume, or mucin volume. However it did increase the number of alveolar attachments in bronchi and respiratory bronchioles. In general, as mucin increased, airway responsiveness decreased. We conclude that perinatal SHS exposure alters in vivo and intrinsic airway responsiveness, and alveolar attachments

The design and installation of Solar Home Systems in rural Cambodia

Directory of Open Access Journals (Sweden)

Rebecca Alice Watts

2016-09-01

Full Text Available This study contends that solar home systems (SHS are an appropriate solution to provide affordable, reliable and clean electricity in rural Cambodia. SHS provide decentralised electricity suitable for the electricity needs of rural households and with the decreasing cost of solar energy technologies, SHS are becoming an increasingly competitive source of energy. This study details the design and installation of two SHS in a rural community in Cambodia. The SHS have replaced the use of kerosene lamps and supplemented car battery usage, which has generated a cost saving of USD$2.50-3.20 per month. The SHS have increased the hours of quality lighting making it possible for users to improve educational outcomes by studying at night and participating in private education classes as well as potentially extending their working hours that provides an opportunity to increase their income. Community involvement in the installation of SHS and participation in an education program has ensured transfer of knowledge about system operation and maintenance at a local level that has ensured economic, social and environmental were benefits. This study builds a case in support of solar energy at the household level in rural Cambodia and makes recommendations for the deployment of SHS in rural communities throughout the developing world.

Propolis-Sahara honeys preparation exhibits antibacterial and anti-biofilm activity against bacterial biofims formed on urinary catheters

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Saad Aissat

2016-11-01

Full Text Available Objective: To evaluate the antibacterial effect of Sahara honeys (SHs against bacterial biofilms formed on urinary catheters in combination with propolis-Sahara honeys (P-SHs. Methods: Three clinical isolates were subjected to biofilm detection methods. The antibacterial and anti-biofilm activity for SHs and P-SHs were determined using agar well diffusion and the percentage of biofilm inhibition (PBI methods. Results: The PBI for Gram-positive bacteria [Staphylococcus aureus (S. aureus] was in the range of 0%–20%, while PBI for Gram-negative bacteria [Pseudomonas aeruginosa and Escherichia coli (E. coli] were in range of 17%–57% and 16%–65%, respectively. The highest PBI (65% was produced by SH2 only on E. coli. In agar well diffusion assay, zones of inhibition ranged from 11–20 mm (S. aureus, 9–19 mm (Pseudomonas aeruginosa and 11–19 mm (E. coli. The highest inhibition (20 mm was produced by SH1 only on S. aureus. In addition, the treatment of SHs and P-SHs catheters with a polymicrobial biofilms reduced biofilm formation after 48 h exposure period. Conclussions: SHs and P-SHs applied as a natural agent can be used as a prophylactic agent to prevent the formation of in vitro biofilm.

Prenatal Secondhand Smoke Exposure and Infant Birth Weight in China

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Adolfo Correa

2012-09-01

Full Text Available Epidemiologic evidence provides some support for a causal association between maternal secondhand smoke (SHS exposure during pregnancy and reduction in infant birth weight. The purpose of this cross-sectional study is to examine the magnitude of this association in China, where both prevalence and dose of SHS exposure are thought to be higher than in U.S. populations. Women who gave birth in Beijing and Changchun September 2000–November 2001 were interviewed to quantify self-reported prenatal SHS exposure. Their medical records were reviewed for data on pregnancy complications and birth outcomes. Non-smoking women who delivered term babies (≥37 weeks gestation were included in the study (N = 2,770. Nearly a quarter of the women (24% reported daily SHS exposure, 47% reported no prenatal exposure, and 75% denied any SHS exposure from the husband smoking at home. Overall, no deficit in mean birth weight was observed with exposure from all sources of SHS combined (+11 grams, 95% CI: +2, +21. Infants had higher mean birth weights among the exposed than the unexposed for all measures of SHS exposure. Future studies on SHS exposure and infant birth weight in China should emphasize more objective measures of exposure to quantify and account for any exposure misclassification.

Secondhand smoke exposure in cars among middle and high school students--United States, 2000-2009.

Science.gov (United States)

King, Brian A; Dube, Shanta R; Tynan, Michael A

2012-03-01

Exposure to secondhand smoke (SHS) from cigarettes poses a significant health risk to nonsmokers. Among youth, the home is the primary source of SHS. However, little is known about youth exposure to SHS in other nonpublic areas, particularly motor vehicles. Data were obtained from the 2000, 2002, 2004, 2006, and 2009 waves of the National Youth Tobacco Survey, a nationally representative survey of US students in grades 6 to 12. Trends in SHS exposure in a car were assessed across survey years by school level, gender, and race/ethnicity by using binary logistic regression. From 2000 to 2009, the prevalence of SHS exposure in cars declined significantly among both nonsmokers (39.0%-22.8%; trend P race/ethnicity subgroups. SHS exposure in cars decreased significantly among US middle and high school students from 2000 to 2009. Nevertheless, in 2009, over one-fifth of nonsmoking students were exposed to SHS in cars. Jurisdictions should expand comprehensive smoke-free policies that prohibit smoking in worksites and public places to also prohibit smoking in motor vehicles occupied by youth.

Secondhand Smoke Exposure in Cars Among Middle and High School Students—United States, 2000–2009

Science.gov (United States)

King, Brian A.; Dube, Shanta R.; Tynan, Michael A.

2015-01-01

OBJECTIVE Exposure to secondhand smoke (SHS) from cigarettes poses a significant health risk to nonsmokers. Among youth, the home is the primary source of SHS. However, little is known about youth exposure to SHS in other nonpublic areas, particularly motor vehicles. METHODS Data were obtained from the 2000, 2002, 2004, 2006, and 2009 waves of the National Youth Tobacco Survey, a nationally representative survey of US students in grades 6 to 12. Trends in SHS exposure in a car were assessed across survey years by school level, gender, and race/ethnicity by using binary logistic regression. RESULTS From 2000 to 2009, the prevalence of SHS exposure in cars declined significantly among both nonsmokers (39.0%–22.8%; trend P race/ethnicity subgroups. CONCLUSIONS SHS exposure in cars decreased significantly among US middle and high school students from 2000 to 2009. Nevertheless, in 2009, over one-fifth of nonsmoking students were exposed to SHS in cars. Jurisdictions should expand comprehensive smoke-free policies that prohibit smoking in worksites and public places to also prohibit smoking in motor vehicles occupied by youth. PMID:22311992

The association between second-hand smoke exposure and depressive symptoms among pregnant women.

Science.gov (United States)

Huang, Jingya; Wen, Guoming; Yang, Weikang; Yao, Zhenjiang; Wu, Chuan'an; Ye, Xiaohua

2017-10-01

Tobacco smoking and depression are strongly associated, but the possible association between second-hand smoke (SHS) exposure and depression is unclear. This study aimed to examine the possible relation between SHS exposure and depressive symptoms among pregnant women. A cross-sectional survey was conducted in Shenzhen, China, using a multistage sampling method. The univariable and multivariable logistic regression models were used to explore the associations between SHS exposure and depressive symptoms. Among 2176 pregnant women, 10.5% and 2.0% were classified as having probable and severe depressive symptoms. Both binary and multinomial logistic regression revealed that there were significantly increased risks of severe depressive symptoms corresponding to SHS exposure in homes or regular SHS exposure in workplaces using no exposure as reference. In addition, greater frequency of SHS exposure was significantly associated with the increased risk of severe depressive symptoms. Our findings suggest that SHS exposure is positively associated with depressive symptoms in a dose-response manner among the pregnant women. Copyright © 2017 Elsevier B.V. All rights reserved.

Are slide-hold-slide tests a good analogue for the seismic cycle?

Science.gov (United States)

van den Ende, Martijn; Niemeijer, André; Marketos, George; Spiers, Christopher

2017-04-01

Earthquakes are among the most disruptive of natural hazards known to man. Owing to their destructive potential and poor predictability, earthquakes and unstable frictional sliding in general receive considerable attention, both in experimental and in modelling studies. For reliable seismic hazard assessments, accurate predictions of the failure strength of seismogenic faults is paramount. To study the time-dependent restrengthening (or "healing") of faults in a laboratory setting, the slide-hold-slide (SHS) method is commonly employed as an analogue for the seismic cycle. Using this method, it is assumed that the rate of restrengthening as observed in SHS tests is similar to the rate of restrengthening of natural faults during the interseismic phase. However, the dynamic and kinematic boundary conditions of SHS tests are inherently different to those of a fault that is being tectonically loaded. As such, it can be questioned whether SHS tests (in which the interseismic period is characterised by stress relaxation) yield the same rate of restrengthening as would be expected from laboratory stick-slip or natural seismic cycles (characterised by a more complex stress history). This question could in principle be addressed experimentally by comparing the results from SHS tests with the stress drop and recurrence time of regular stick-slips. However, due to technical limitations, direct comparison between SHS and stick-slips is non-trivial, and uncertainties in extrapolating the laboratory results remain. To assess the validity of SHS tests as an analogue for the seismic cycle, we simulate laboratory SHS tests as well as stick-slips using the Discrete Element Method (DEM). DEM is a particle-based numerical technique that is suitable for modelling granular media, such as fault gouges. Its constitutive relations are linked to grain-scale micro-processes, and, in the work presented here, we incorporate pressure solution creep and frictional sliding. The simultaneous

A D-D/D-T fusion reaction based neutron generator system for liver tumor BNCT

International Nuclear Information System (INIS)

Koivunoro, H.; Lou, T.P.; Leung, K. N.; Reijonen, J.

2003-01-01

Boron-neutron capture therapy (BNCT) is an experimental radiation treatment modality used for highly malignant tumor treatments. Prior to irradiation with low energetic neutrons, a 10B compound is located selectively in the tumor cells. The effect of the treatment is based on the high LET radiation released in the 10 B(n,α) 7 Li reaction with thermal neutrons. BNCT has been used experimentally for brain tumor and melanoma treatments. Lately applications of other severe tumor type treatments have been introduced. Results have shown that liver tumors can also be treated by BNCT. At Lawrence Berkeley National Laboratory, various compact neutron generators based on D-D or D-T fusion reactions are being developed. The earlier theoretical studies of the D-D or D-T fusion reaction based neutron generators have shown that the optimal moderator and reflector configuration for brain tumor BNCT can be created. In this work, the applicability of 2.5 MeV neutrons for liver tumor BNCT application was studied. The optimal neutron energy for external liver treatments is not known. Neutron beams of different energies (1eV < E < 100 keV) were simulated and the dose distribution in the liver was calculated with the MCNP simulation code. In order to obtain the optimal neutron energy spectrum with the D-D neutrons, various moderator designs were performed using MCNP simulations. In this article the neutron spectrum and the optimized beam shaping assembly for liver tumor treatments is presented

Development of a skeletal multi-component fuel reaction mechanism based on decoupling methodology

International Nuclear Information System (INIS)

Mohan, Balaji; Tay, Kun Lin; Yang, Wenming; Chua, Kian Jon

2015-01-01

Highlights: • A compact multi-component skeletal reaction mechanism was developed. • Combined bio-diesel and PRF mechanism was proposed. • The mechanism consists of 68 species and 183 reactions. • Well validated against ignition delay times, flame speed and engine results. - Abstract: A new coupled bio-diesel surrogate and primary reference fuel (PRF) oxidation skeletal mechanism has been developed. The bio-diesel surrogate sub-mechanism consists of oxidation sub-mechanisms of Methyl decanoate (MD), Methyl 9-decenoate (MD9D) and n-Heptane fuel components. The MD and MD9D are chosen to represent the saturated and unsaturated methyl esters respectively in bio-diesel fuels. Then, a reduced iso-Octane oxidation sub-mechanism is added to the bio-diesel surrogate sub-mechanism. Then, all the sub-mechanisms are integrated to a reduced C_2–C_3 mechanism, detailed H_2/CO/C_1 mechanism and reduced NO_x mechanism based on decoupling methodology. The final mechanism consisted of 68 species and 183 reactions. The mechanism was well validated with shock-tube ignition delay times, laminar flame speed and 3D engine simulations.

Fiber coating/matrix reactions in silicon-base ceramic matrix composites

International Nuclear Information System (INIS)

Lee, K.N.; Jacobson, N.S.

1992-01-01

The Knudsen cell technique and coupons of carbon coated Si3N4 and BN coated SiC were employed to study the possible reactions at the SiC/C/Si3N4 and SiC/BN/SiC interface. Carbon reacts with Si3N4 to form gaseous N2 and solid SiC. Solid SiC acts as a physical barrier to the reaction, which prevents the generation of high N2 pressure predicted from thermochemical calculations. Thus, deleterious effects of the reaction to the composite are limited. Limited reactions between BN and C-rich SiC was observed. However, the vapor pressure was so low that it is not likely to cause any interfacial instability. The predicted formation of a BN-C solid solution was not observed. 10 refs

Fiber coating/matrix reactions in silicon-base ceramic matrix composites

Science.gov (United States)

Lee, K. N.; Jacobson, N. S.

1992-01-01

The Knudsen cell technique and coupons of carbon coated Si3N4 and BN coated SiC were employed to study the possible reactions at the SiC/C/Si3N4 and SiC/BN/SiC interface. Carbon reacts with Si3N4 to form gaseous N2 and solid SiC. Solid SiC acts as a physical barrier to the reaction, which prevents the generation of high N2 pressure predicted from thermochemical calculations. Thus, deleterious effects of the reaction to the composite are limited. Limited reactions between BN and C-rich SiC was observed. However, the vapor pressure was so low that it is not likely to cause any interfacial instability. The predicted formation of a BN-C solid solution was not observed.

Ignition, Combustion and Tuning of Nanocomposite Thermites

Science.gov (United States)

2010-01-01

silver nitrate and potassium 165 iodate or sodium iodate, using a modification of a literature method156. A solution of 30.97 g of AgNO3 in 125...Center Weapons Division (NAWCWD) by precipitation from aqueous solutions of silver nitrate and potassium iodate or sodium iodate, using a modification...adjustable wrench to tighten 1/2 turn past finger tight). -Attach one banana wire to the very top, other to the base. -Test for continuity. If you increase

From the American Academy of Pediatrics: Policy statement--Tobacco use: a pediatric disease.

Science.gov (United States)

2009-11-01

Tobacco use and secondhand tobacco-smoke (SHS) exposure are major national and international health concerns. Pediatricians and other clinicians who care for children are uniquely positioned to assist patients and families with tobacco-use prevention and treatment. Understanding the nature and extent of tobacco use and SHS exposure is an essential first step toward the goal of eliminating tobacco use and its consequences in the pediatric population. The next steps include counseling patients and family members to avoid SHS exposures or cease tobacco use; advocacy for policies that protect children from SHS exposure; and elimination of tobacco use in the media, public places, and homes. Three overarching principles of this policy can be identified: (1) there is no safe way to use tobacco; (2) there is no safe level or duration of exposure to SHS; and (3) the financial and political power of individuals, organizations, and government should be used to support tobacco control. Pediatricians are advised not to smoke or use tobacco; to make their homes, cars, and workplaces tobacco free; to consider tobacco control when making personal and professional decisions; to support and advocate for comprehensive tobacco control; and to advise parents and patients not to start using tobacco or to quit if they are already using tobacco. Prohibiting both tobacco advertising and the use of tobacco products in the media is recommended. Recommendations for eliminating SHS exposure and reducing tobacco use include attaining universal (1) smoke-free home, car, school, work, and play environments, both inside and outside, (2) treatment of tobacco use and dependence through employer, insurance, state, and federal supports, (3) implementation and enforcement of evidence-based tobacco-control measures in local, state, national, and international jurisdictions, and (4) financial and systems support for training in and research of effective ways to prevent and treat tobacco use and SHS

Reactive thermal waves in energetic materials

Energy Technology Data Exchange (ETDEWEB)

Hill, Larry G [Los Alamos National Laboratory

2009-01-01

Reactive thermal waves (RTWs) arise in several energetic material applications, including self-propagating high-temperature synthesis (SHS), high explosive cookoff, and the detonation of heterogeneous explosives. In this paper I exmaine ideal RTWs, by which I mean that (1) material motion is neglected, (2) the state dependence of reaction is Arrhenius in the temperature, and (3) the reaction rate is modulated by an arbitrary mass-fraction-based reaction progress function. Numerical simulations demonstrate that one's natural intuition, which is based mainly upon experience with inert materials and which leads one to expect diffusion processes to become relatively slow after a short time period, is invalid for high energy, state-sensitive reactive systems. Instead, theory predicts that RTWs can propagate at very high speeds. This result agrees with estimates for detonating heterogeneous explosives, which indicate that RTWs must spread from hot-spot nucleation sites at rates comparable to the detonation speed in order to produce experimentally-observed reaction zone thicknesses. Using dimensionless scaling and further invoking the high activation energy approximation, I obtain an analytic formula for the steady plane RTW speed from numerical calculations. I then compute the RTW speed for real explosives, and discuss aspects of their behavior.

Self-reported adverse food reactions and anaphylaxis in the SchoolNuts study: A population-based study of adolescents.

Science.gov (United States)

McWilliam, Vicki L; Koplin, Jennifer J; Field, Michael J; Sasaki, Mari; Dharmage, Shyamali C; Tang, Mimi L K; Sawyer, Susan M; Peters, Rachel L; Allen, Katrina J

2018-03-01

Adolescents are at the highest risk of death from anaphylaxis, yet few population-based studies have described the frequencies and risk factors for allergic reactions caused by accidental allergen ingestion in this group. We describe the prevalence, frequency, and associated risk factors for recent adverse food reactions in 10- to 14-year-olds in Melbourne, Australia, recruited from a stratified, random, population-based sample of schools (SchoolNuts, n = 9663; 48% response rate). Self-reported food allergy and adverse reaction details, including anaphylaxis, were identified by using a student questionnaire over the past year. Of 547 students with possible IgE-mediated food allergy, 243 (44.4%; 95% CI, 40.3% to 48.7%) reported a reaction to a food. Fifty-three (9.7%; 95% CI, 7.2% to 12.2%) students reported 93 anaphylaxis episodes. Peanut and tree nuts were the most common food triggers. Among students with current IgE-mediated food allergy, those with resolved or current asthma (adjusted odds ratio [aOR], 1.9 [95% CI, 1.1-1.3] and 1.7 [95% CI, 1.1-2.6]) and those with more than 2 food allergies (aOR, 1.9 [95% CI, 1.1-3.1]) were at greatest risk of any adverse food reaction, and those with nut allergy were most at risk of severe reactions (aOR, 2.9 [95% CI, 1.1-4.4]). Resolved or current asthma was not associated with increased risk of severe reactions (aOR, 0.8 [95% CI, 0.3-2.2] and 1.6 [95% CI, 0.7-3.7]). Adolescents with food allergy are frequently exposed to food allergens. Those with asthma and more than 2 food allergies were at the greatest risk for adverse food reactions. Those with nut allergies were most at risk of severe reactions. Copyright © 2017 American Academy of Allergy, Asthma & Immunology. All rights reserved.

Noncanonical Reactions of Flavoenzymes

Directory of Open Access Journals (Sweden)

Pablo Sobrado

2012-11-01

Full Text Available Enzymes containing flavin cofactors are predominantly involved in redox reactions in numerous cellular processes where the protein environment modulates the chemical reactivity of the flavin to either transfer one or two electrons. Some flavoenzymes catalyze reactions with no net redox change. In these reactions, the protein environment modulates the reactivity of the flavin to perform novel chemistries. Recent mechanistic and structural data supporting novel flavin functionalities in reactions catalyzed by chorismate synthase, type II isopentenyl diphosphate isomerase, UDP-galactopyranose mutase, and alkyl-dihydroxyacetonephosphate synthase are presented in this review. In these enzymes, the flavin plays either a direct role in acid/base reactions or as a nucleophile or electrophile. In addition, the flavin cofactor is proposed to function as a “molecular scaffold” in the formation of UDP-galactofuranose and alkyl-dihydroxyacetonephosphate by forming a covalent adduct with reaction intermediates.

Nonequilibrium thermodynamics and a fluctuation theorem for individual reaction steps in a chemical reaction network

International Nuclear Information System (INIS)

Pal, Krishnendu; Das, Biswajit; Banerjee, Kinshuk; Gangopadhyay, Gautam

2015-01-01

We have introduced an approach to nonequilibrium thermodynamics of an open chemical reaction network in terms of the propensities of the individual elementary reactions and the corresponding reverse reactions. The method is a microscopic formulation of the dissipation function in terms of the relative entropy or Kullback-Leibler distance which is based on the analogy of phase space trajectory with the path of elementary reactions in a network of chemical process. We have introduced here a fluctuation theorem valid for each opposite pair of elementary reactions which is useful in determining the contribution of each sub-reaction on the nonequilibrium thermodynamics of overall reaction. The methodology is applied to an oligomeric enzyme kinetics at a chemiostatic condition that leads the reaction to a nonequilibrium steady state for which we have estimated how each step of the reaction is energy driven or entropy driven to contribute to the overall reaction. (paper)

Reaction Qualifications Revisited

DEFF Research Database (Denmark)

Lippert-Rasmussen, Kasper

2009-01-01

  When, in a competitive sphere, people are selected on the basis of qualifications only, their chances of acquiring positions of advantage may seem to depend entirely upon their abilities, not discriminatory bias. However, if reaction qualifications - i.e. characteristics which contribute...... to a person's effectiveness by causing a favourable reaction in customers, co-workers etc. (for short: recipients) - are involved, this assumption is false. Building on work by Wertheimer, Mason, and Miller, this paper proposes an account of the reaction qualifications that count, from the point of view...... of merit. Specifically, it preserves symmetry between negative evaluations of antimeritocratic bases of selection and negative evaluations of qualifications rooted in comparable antimeritocratic reactions. So if employers should not select among applicants on the basis of their (the employers') racial...

Reaction Qualifications Revisited

DEFF Research Database (Denmark)

Lippert-Rasmussen, Kasper

2009-01-01

to a person's effectiveness by causing a favourable reaction in customers, co-workers etc. (for short: recipients) - are involved, this assumption is false. Building on work by Wertheimer, Mason, and Miller, this paper proposes an account of the reaction qualifications that count, from the point of view...... preferences, recipients should not respond to the applicant actually hired on the basis of their (the recipients') racial preferences. My account decomposes the meritocratic ideal into four separate norms, one of which applies to recipients rather than to selectors. Finally, it defends the view that reaction...... qualifications based on antimeritocratic reactions, while not unproblematic, are not entirely irrelevant from the point of view of merit. Notably, selectors need not discount them when no one - including the targets of the objectionable preferences - is unfairly disadvantaged. Because not all problematic...

Learning to predict chemical reactions.

Science.gov (United States)

Kayala, Matthew A; Azencott, Chloé-Agathe; Chen, Jonathan H; Baldi, Pierre

2011-09-26

Being able to predict the course of arbitrary chemical reactions is essential to the theory and applications of organic chemistry. Approaches to the reaction prediction problems can be organized around three poles corresponding to: (1) physical laws; (2) rule-based expert systems; and (3) inductive machine learning. Previous approaches at these poles, respectively, are not high throughput, are not generalizable or scalable, and lack sufficient data and structure to be implemented. We propose a new approach to reaction prediction utilizing elements from each pole. Using a physically inspired conceptualization, we describe single mechanistic reactions as interactions between coarse approximations of molecular orbitals (MOs) and use topological and physicochemical attributes as descriptors. Using an existing rule-based system (Reaction Explorer), we derive a restricted chemistry data set consisting of 1630 full multistep reactions with 2358 distinct starting materials and intermediates, associated with 2989 productive mechanistic steps and 6.14 million unproductive mechanistic steps. And from machine learning, we pose identifying productive mechanistic steps as a statistical ranking, information retrieval problem: given a set of reactants and a description of conditions, learn a ranking model over potential filled-to-unfilled MO interactions such that the top-ranked mechanistic steps yield the major products. The machine learning implementation follows a two-stage approach, in which we first train atom level reactivity filters to prune 94.00% of nonproductive reactions with a 0.01% error rate. Then, we train an ensemble of ranking models on pairs of interacting MOs to learn a relative productivity function over mechanistic steps in a given system. Without the use of explicit transformation patterns, the ensemble perfectly ranks the productive mechanism at the top 89.05% of the time, rising to 99.86% of the time when the top four are considered. Furthermore, the system

Learning to Predict Chemical Reactions

Science.gov (United States)

Kayala, Matthew A.; Azencott, Chloé-Agathe; Chen, Jonathan H.

2011-01-01

Being able to predict the course of arbitrary chemical reactions is essential to the theory and applications of organic chemistry. Approaches to the reaction prediction problems can be organized around three poles corresponding to: (1) physical laws; (2) rule-based expert systems; and (3) inductive machine learning. Previous approaches at these poles respectively are not high-throughput, are not generalizable or scalable, or lack sufficient data and structure to be implemented. We propose a new approach to reaction prediction utilizing elements from each pole. Using a physically inspired conceptualization, we describe single mechanistic reactions as interactions between coarse approximations of molecular orbitals (MOs) and use topological and physicochemical attributes as descriptors. Using an existing rule-based system (Reaction Explorer), we derive a restricted chemistry dataset consisting of 1630 full multi-step reactions with 2358 distinct starting materials and intermediates, associated with 2989 productive mechanistic steps and 6.14 million unproductive mechanistic steps. And from machine learning, we pose identifying productive mechanistic steps as a statistical ranking, information retrieval, problem: given a set of reactants and a description of conditions, learn a ranking model over potential filled-to-unfilled MO interactions such that the top ranked mechanistic steps yield the major products. The machine learning implementation follows a two-stage approach, in which we first train atom level reactivity filters to prune 94.00% of non-productive reactions with a 0.01% error rate. Then, we train an ensemble of ranking models on pairs of interacting MOs to learn a relative productivity function over mechanistic steps in a given system. Without the use of explicit transformation patterns, the ensemble perfectly ranks the productive mechanism at the top 89.05% of the time, rising to 99.86% of the time when the top four are considered. Furthermore, the system

Parametric sensitivity analysis for biochemical reaction networks based on pathwise information theory.

Science.gov (United States)

Pantazis, Yannis; Katsoulakis, Markos A; Vlachos, Dionisios G

2013-10-22

Stochastic modeling and simulation provide powerful predictive methods for the intrinsic understanding of fundamental mechanisms in complex biochemical networks. Typically, such mathematical models involve networks of coupled jump stochastic processes with a large number of parameters that need to be suitably calibrated against experimental data. In this direction, the parameter sensitivity analysis of reaction networks is an essential mathematical and computational tool, yielding information regarding the robustness and the identifiability of model parameters. However, existing sensitivity analysis approaches such as variants of the finite difference method can have an overwhelming computational cost in models with a high-dimensional parameter space. We develop a sensitivity analysis methodology suitable for complex stochastic reaction networks with a large number of parameters. The proposed approach is based on Information Theory methods and relies on the quantification of information loss due to parameter perturbations between time-series distributions. For this reason, we need to work on path-space, i.e., the set consisting of all stochastic trajectories, hence the proposed approach is referred to as "pathwise". The pathwise sensitivity analysis method is realized by employing the rigorously-derived Relative Entropy Rate, which is directly computable from the propensity functions. A key aspect of the method is that an associated pathwise Fisher Information Matrix (FIM) is defined, which in turn constitutes a gradient-free approach to quantifying parameter sensitivities. The structure of the FIM turns out to be block-diagonal, revealing hidden parameter dependencies and sensitivities in reaction networks. As a gradient-free method, the proposed sensitivity analysis provides a significant advantage when dealing with complex stochastic systems with a large number of parameters. In addition, the knowledge of the structure of the FIM can allow to efficiently address

Validity of self-reported exposure to second-hand smoke in hospitality venues.

Science.gov (United States)

Galán, Iñaki; Mayo, Elga; López, María J; Pérez-Ríos, Mónica; Fu, Marcela; Martínez-Sánchez, Jose M; Schiaffino, Anna; Moncada, Albert; Montes, Agustín; Nebot, Manel; Fernández, Esteve

2014-08-01

The aim was to assess the validity of self-reported exposure to second-hand smoke (SHS) in 50 hospitality venues of Madrid (Spain) in 2010, taking as a reference vapour-phase nicotine measured by active sampling. The questions posed in the questionnaire permitted distinguishing between the different levels of SHS. However, the moderate relationship found (Spearman׳s correlation=0.387, phospitality venues, based solely on self-reported information, should be used with caution. Copyright © 2014 Elsevier Inc. All rights reserved.

Vital Signs: Disparities in Nonsmokers’ Exposure to Secondhand Smoke — United States, 1999–2012

Science.gov (United States)

Homa, David M.; Neff, Linda J.; King, Brian A.; Caraballo, Ralph S.; Bunnell, Rebecca E.; Babb, Stephen D.; Garrett, Bridgette E.; Sosnoff, Connie S.; Wang, Lanqing

2015-01-01

Background Exposure to secondhand smoke (SHS) from burning tobacco causes disease and death in nonsmoking children and adults. No risk-free level of SHS exposure exists. Methods National Health and Nutrition Examination Survey (NHANES) data from 1999–2012 were used to examine SHS exposure among the nonsmoking population aged ≥3 years. SHS exposure among nonsmokers was defined as a serum cotinine level (a metabolite of nicotine) of 0.05–10 ng/mL. SHS exposure was assessed overall and by age, sex, race/ethnicity, poverty level, education, and whether the respondent owned or rented their housing. Results Prevalence of SHS exposure in nonsmokers declined from 52.5% during 1999–2000 to 25.3% during 2011–2012. During this period, declines were observed for all population subgroups, but disparities exist. During 2011–2012, SHS was highest among: children aged 3–11 years (40.6%), non-Hispanic blacks (46.8%), persons living below the poverty level (43.2%), and persons living in rental housing (36.8%). Among children aged 3–11 years, 67.9% of non-Hispanic blacks were exposed to SHS compared with 37.2% of non-Hispanic whites and 29.9% of Mexican Americans. Conclusion Overall, SHS exposure in the United States has been reduced by half since 1999–2000. However, 58 million persons were still exposed to SHS during 2011–2012, and exposure remains higher among children, non-Hispanic blacks, those living in poverty, and those who rent their housing. Implications for Public Health Practice Eliminating smoking in indoor spaces fully protects nonsmokers from SHS exposure; separating smokers from nonsmokers, cleaning the air and ventilating buildings cannot completely eliminate exposure. Continued efforts to promote implementation of comprehensive statewide laws prohibiting smoking in workplaces and public places, smoke-free policies in multiunit housing, and voluntary smoke-free home and vehicle rules are critical to protect nonsmokers from this preventable health

Self-propagating high-temperature synthesis of Sr-doped LaMnO3 perovskite as oxidation catalyst

International Nuclear Information System (INIS)

Hirano, T.; Purwanto, H.; Watanabe, T.; Akiyama, T.

2007-01-01

Sr-doped LaMnO 3 perovskite oxide has been focused on as one of the alternative catalysts to precious metals such as platinum that are used for cleaning automotive emission gas. The conventional Solid-state reaction method is a popular productive process for perovskite oxide, however, it is time and energy consuming process because it requires repeated prolonged heat treatment at high temperatures. Therefore, the purposes of this work are to produce Sr-doped LaMnO 3 perovskite by using Self-propagating high-temperature synthesis (SHS) and experimentally examine the oxidation catalytic activity of the product for cleaning automotive emission gas. In the SHS, powders of La 2 O 3 , SrCO 3 , Mn and NaClO 4 were well mixed at the desired ratio and poured in a graphite crucible, where at one end it was ignited by using an electrically heated carbon foil. The wave of exothermic reaction due to oxidation of manganese propagated to the other end in a short time. The obtained products were characterized by means of XRD, FE-SEM, BET and particle size distribution analysis and then evaluated via catalytic oxidation tests by using propane in a fixed bed reactor at several temperatures. From the XRD analysis, the products had the desired composition of La 1-x Sr x MnO 3 (x = 0, 0.1, 0.2 and 0.4) perovskite, in which the replacing ratio x of La and Sr in the products was easily controlled by changing the mixing ratio of raw materials. The catalytic activity test showed that the samples exhibited good catalytic activity for propane oxidation over 200 deg. C , although the products had a relatively small surface area. SHS showed the potential for the production of a relatively inexpensive catalytic converter

Policies on smoking in the casino workplace and their impact on smoking behavior among employees: Case study of casino workers in Macao

OpenAIRE

Chan, S. H.; Pilkington, P.; Wan, Y. K. P.; Faculty of Business Administration, University of Macao; Institute for Sustainability, Health and Environment, UWE

2012-01-01

Exposure to second hand smoke (SHS) is a major health concern, contributing to a range of adverse health effects. Workers in the hospitality industry are often exposed to increased levels of SHS in the workplace, and casino workers in particular have been shown to be exposed to high levels of SHS. During the past decade, authorities worldwide have introduced smoke-free legislation in enclosed public places, primarily to protect workers from the harmful effects of SHS. Importantly, implementat...

The Electronic Flux in Chemical Reactions. Insights on the Mechanism of the Maillard Reaction

Science.gov (United States)

Flores, Patricio; Gutiérrez-Oliva, Soledad; Herrera, Bárbara; Silva, Eduardo; Toro-Labbé, Alejandro

2007-11-01

The electronic transfer that occurs during a chemical process is analysed in term of a new concept, the electronic flux, that allows characterizing the regions along the reaction coordinate where electron transfer is actually taking place. The electron flux is quantified through the variation of the electronic chemical potential with respect to the reaction coordinate and is used, together with the reaction force, to shed light on reaction mechanism of the Schiff base formation in the Maillard reaction. By partitioning the reaction coordinate in regions in which different process might be taking place, electronic reordering associated to polarization and transfer has been identified and found to be localized at specific transition state regions where most bond forming and breaking occur.

Excessive Exposure to Secondhand Tobacco Smoke among Hospitality Workers in Kyrgyzstan

Directory of Open Access Journals (Sweden)

Ana Navas-Acien

2010-03-01

Full Text Available The aim of this study was to assess the levels of secondhand smoke (SHS exposure of men and women in public places in Kyrgyzstan. This cross-sectional study involved 10 bars and restaurants in Bishkek the capital city of Kyrgyzstan. Smoking was allowed in all establishments. Median (interquartile range air nicotine concentrations were 6.82 (2.89, 8.86 μg/m3. Employees were asked about their smoking history and exposure to SHS at work. Employees were exposed to SHS for mean (SD 13.5 (3.6 hours a day and 5.8 (1.4 days a week. Women were exposed to more hours of SHS at work compared to men. Hospitality workers are exposed to excessive amounts of SHS from customers. Legislation to ban smoking in public places including bars and restaurants is urgently needed to protect workers and patrons from the harmful effects of SHS.

Excessive Exposure to Secondhand Tobacco Smoke among Hospitality Workers in Kyrgyzstan

Science.gov (United States)

Vinnikov, Denis; Brimkulov, Nurlan; Shahrir, Shahida; Breysse, Patrick; Navas-Acien, Ana

2010-01-01

The aim of this study was to assess the levels of secondhand smoke (SHS) exposure of men and women in public places in Kyrgyzstan. This cross-sectional study involved 10 bars and restaurants in Bishkek the capital city of Kyrgyzstan. Smoking was allowed in all establishments. Median (interquartile range) air nicotine concentrations were 6.82 (2.89, 8.86) μg/m3. Employees were asked about their smoking history and exposure to SHS at work. Employees were exposed to SHS for mean (SD) 13.5 (3.6) hours a day and 5.8 (1.4) days a week. Women were exposed to more hours of SHS at work compared to men. Hospitality workers are exposed to excessive amounts of SHS from customers. Legislation to ban smoking in public places including bars and restaurants is urgently needed to protect workers and patrons from the harmful effects of SHS. PMID:20617012

Secondhand smoke exposure and serum cotinine levels among current smokers in the USA.

Science.gov (United States)

Lindsay, Ryan P; Tsoh, Janice Y; Sung, Hai-Yen; Max, Wendy

2016-03-01

Secondhand smoke (SHS) likely provides additional exposure to nicotine and toxins for smokers, but has been understudied. Our objective was to determine whether SHS exposure among smokers yields detectable differences in cotinine levels compared with unexposed smokers at the population level. Using the US National Health and Nutrition Examination Survey (NHANES) for the years 1999-2012, we compared serum cotinine levels of 4547 current adult cigarette smokers stratified by self-reported SHS exposure sources (home and/or work) and smoking intensity. A weighted multivariable linear regression model determined the association between SHS exposure and cotinine levels among smokers. Smokers with SHS exposure at home (43.8%) had higher cotinine levels (β=0.483, p≤0.001) compared with those with no SHS exposure at home after controlling for the number of cigarettes smoked per day and number of days smoked in the previous 5 days, survey year, age, gender and education. Smokers with SHS exposure at work (20.0%) did not have significantly higher cotinine levels after adjustment. The adjusted geometric mean cotinine levels of light smokers (1-9 cigarettes per day) with no SHS exposure, exposure at work only, home only, and both home and work were 52.0, 62.7, 67.2, 74.4 ng/mL, respectively, compared with 219.4, 220.9, 255.2, 250.5 ng/mL among moderate/heavy smokers (≥10 cigarettes per day). Smokers living in residences where others smoke inside the home had significantly higher cotinine levels than smokers reporting no SHS exposure, regardless of individual smoking intensity. Future research should target the role that SHS exposure may have in nicotine dependence, cessation outcomes and other health impacts among smokers. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Exposure to secondhand smoke from neighbours and respiratory symptoms in never-smoking adolescents in Hong Kong: a cross-sectional study.

Science.gov (United States)

Leung, Lok Tung; Ho, Sai Yin; Wang, Man Ping; Lo, Wing Sze; Lam, Tai Hing

2015-11-04

To investigate secondhand smoke (SHS) exposure at home from neighbours in Hong Kong adolescents and its association with respiratory symptoms in never-smokers. A cross-sectional study. 79 randomly selected secondary schools in Hong Kong. 61,810 secondary 1 (USA grade 7) to 7 students, in which 50,762 never-smokers were identified and included in the analysis of the association between SHS exposure at home from neighbours and respiratory symptoms. Smoking status, family smoking status, SHS exposure at home from inside the home and from neighbours in the past 7 days, respiratory symptoms and sociodemographic characteristics were reported. Adjusted ORs (AORs) of respiratory symptoms for SHS exposure from the 2 sources in never-smokers were calculated using logistic regression. In all students, 33.2% were exposed to SHS at home, including 16.2% from inside the home only, 10.0% from neighbours only and 7.0% from both. The prevalence of SHS exposure from neighbours was 17.1%, including 13.5% for 1-4 days/week and 3.6% for 5-7 days/week. In never-smokers (n=50,762), respiratory symptoms were significantly associated with SHS exposure from neighbours with AORs (95% CI) of 1.29 (1.20 to 1.39) for any exposure (pexposure at home from any source, the AORs were 1.16 (1.07 to 1.25) for SHS from inside the home only (pexposure at home from neighbours was prevalent in Hong Kong adolescents, and was associated with respiratory symptoms in never-smokers. SHS exposure at home may be underestimated by ignoring the neighbouring source. Smoke-free housing policy is needed to protect children and adolescents from harms of SHS. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Exposure to tobacco secondhand smoke and its associated factors among non-smoking adults in smoking-restricted and non-restricted areas: findings from a nationwide study in Malaysia.

Science.gov (United States)

Lim, Kuang Hock; Teh, Chien Huey; Nik Mohamed, Mohamad Haniki; Pan, Sayan; Ling, Miaw Yn; Mohd Yusoff, Muhammad Fadhli; Hassan, Noraryana; Baharom, Nizam; Dawam, Netty Darwina; Ismail, Norliana; Ghazali, Sumarni Mohd; Cheong, Kee Chee; Chong, Kar Hon; Lim, Hui Li

2018-01-08

Secondhand smoke (SHS) has been associated with increased morbidity and mortality. Therefore, the aims of the paper are to assess SHS exposure among non-smoking adults in Malaysia attending various smoking-restricted and non-restricted public areas according to the Control of Tobacco Product Regulations (CTPR) as well as its relationship with various sociodemographic variables. Data were extracted from a cross-sectional study, the Global Adults Tobacco Survey (GATS) 2011 which involved 3269 non-smokers in Malaysia. Data was obtained through face-to-face interviews using a validated pre-tested questionnaire. Factors associated with exposure to SHS were identified via multivariable analysis. The study revealed that almost two-thirds of respondents were exposed to SHS in at least one public area in the past 1 month, with a significantly higher exposure among males (70.6%), those with higher educational attainment (81.4%) and higher income (quintile 1%-73.9%). Besides, the exposure to SHS was almost four times higher in non-restricted areas compared with restricted areas under the CTPR (81.9% vs 22.9). Multivariable analysis revealed that males and younger adults at non-restricted areas were more likely to be exposed to SHS while no significant associated factors of SHS exposure was observed in restricted areas. The study revealed the prevalence of SHS exposure was higher among Malaysian adults. Although smoke-free laws offer protection to non-smokers from exposure to SHS, enforcement activities in restricted areas should be enhanced to ensure strict public abidance. In addition, legislation of restricted areas should also be extended to greatly reduce the SHS exposure among non-smokers in Malaysia. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Well-defined Polymethylene-Based Co/Terpolymers by Combining Anthracene/Maleimide Diels-Alder Reaction with Polyhomologation

KAUST Repository

Hadjichristidis, Nikolaos

2015-05-26

A novel strategy towards well-defined polymethylene-based co/terpolymers, by combining anthracene/maleimide Diels-Alder reaction with polyhomologation, is presented. For the synthesis of diblock copolymers the following approach was applied: a) synthesis of α-anthracene-ω-hydroxy- polymethylene by polyhomologation using tri (9-anthracene-methyl propyl ether) borane as initiator, b) synthesis of furan-protected-maleimide-terminated poly (ε-caprolactone) or polyethylene glycol and c). Diels-Alder reaction between the anthracene and maleimide-terminated polymers. In the case of triblock terpolymers the α-anthracene-ω-hydroxy-polymethylene was used as macroinitiator for the ring-opening polymerization of D, L-lactide to afford an anthracene-terminated PM-b-PLA copolymer, followed by Diels-Alder reaction with furan-protected maleimide-terminated poly (ε-caprolactone) or polyethylene glycol to give the triblock terpolymers. All intermediate and final products were characterized by SEC, 1H NMR, UV-VIS spectroscopy and DSC.

[Secondhand smoke exposure at home and leisure time according to the day of the week (working and non-working day) in Barcelona].

Science.gov (United States)

Martínez-Sánchez, José M; Fu, Marcela; Schiaffino, Anna; Sureda, Xisca; Saltó, Esteve; Moncada, Albert; Ariza, Carles; Nebot, Manel; Pascual, José A; Fernández, Esteve

2012-01-01

The objective of this study is to describe the differences in the exposure to secondhand smoke (SHS) at home and at leisure time according to the day of the week (working and non-working day) which exposure occurs in Barcelona. We carried out a cross-sectional study of a representative sample of adult (>16 years) non-smokers in Barcelona before the Spanish smoking law came into effect (years 2004-2005). We studied the prevalence of exposure to SHS at home and leisure time by means of a questionnaire and a biomarker (salivary cotinine). The questionnaire included questions on exposure to SHS on working days and nonworking days. The prevalence of exposure to SHS at home was 27.4% (6.8% exposed only on working days, 5.7% exposed only on non-working days, and 14.9% exposed on both working and non-working days). The prevalence of exposure to SHS at leisure time was 61.3% (10.7% exposed only on working days, 13.6% exposed only on non-working days, and 37.0% exposed on both working and non-working days). The exposure to SHS only on non-working days at leisure time decreases with age (χ(2) of trend = 183.7; phome on working and non-working days showed higher levels of salivary cotinine concentration, regardless of sex, age group, and educational level. In conclusion, the exposure to SHS occurs mainly during leisure time. Questions on SHS exposure according to working and non-working days allow to characterizing the exposure to SHS, especially when the exposure occurs at leisure time.

Fabrication of hard cermets by in-situ synthesis and infiltration of metal melts into WC powder compacts

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Guanghua Liu

2017-12-01

Full Text Available Hard carbide cermets are prepared by in-situ synthesis and infiltration of metal melts into WC powder compacts. Ni–W and Ni–W–Cr metal melts are in-situ synthesized from thermite reactions and infiltrated into WC powder compacts under high-gravity. During the infiltration, W in the metal melts reacts with WC to form W2C, and more W2C and W are observed at the upper parts of the cermets than the lower parts. The cermets show a maximum hardness of 15.4 GPa, which is higher than most commercial cemented carbides, although they are not fully dense and have a porosity of 15–20%.

Factors Associated with Redundant Sigmoid Colon at Mulago ...

African Journals Online (AJOL)

jen

economic factors between 68 patients .... 50,000 Uganda shillings (Ug. Shs) compared to only 19.9% of the controls (1 US $ = Ug shs 1500). ... the majority of the affected patients in this study had a family income of below 50,000 Ug. shs per month.

Secondhand Smoke Exposure Reduced the Compensatory Effects of IGF-I Growth Signaling in the Aging Rat Hearts.

Science.gov (United States)

Wu, Jia-Ping; Hsieh, Dennis Jine-Yuan; Kuo, Wei-Wen; Han, Chien-Kuo; Pai, Peiying; Yeh, Yu-Lan; Lin, Chien-Chung; Padma, V Vijaya; Day, Cecilia Hsuan; Huang, Chih-Yang

2015-01-01

Secondhand smoke (SHS) exposure is associated with increased risk of cardiovascular disease. Aging is a physiological process that involves progressive impairment of normal heart functions due to increased vulnerability to damage. This study examines secondhand smoke exposure in aging rats to determine the age-related death-survival balance. Rats were placed into a SHS exposure chamber and exposed to smog. Old age male Sprague-Dawley rats were exposed to 10 cigarettes for 30 min, day and night, continuing for one week. After 4 weeks the rats underwent morphological and functional studies. Left ventricular sections were stained with hematoxylin-eosin for histopathological examination. TUNEL detected apoptosis cells and protein expression related death and survival pathway were analyzed using western blot. Death receptor-dependent apoptosis upregulation pathways and the mitochondria apoptosis proteins were apparent in young SHS exposure and old age rats. These biological markers were enhanced in aging SHS-exposed rats. The survival pathway was found to exhibit compensation only in young SHS-exposed rats, but not in the aging rats. Further decrease in the activity of this pathway was observed in aging SHS-exposed rats. TUNEL apoptotic positive cells were increased in young SHS-exposed rats, and in aging rats with or without SHS-exposure. Aging reduces IGF-I compensated signaling with accelerated cardiac apoptotic effects from second-hand smoke.

Correlates of exposure to second-hand smoke in an urban Mediterranean population

Directory of Open Access Journals (Sweden)

Borras Josep

2007-08-01

Full Text Available Abstract Background To describe the socio-demographic factors associated with exposure to second-hand smoke (SHS in different settings (home, leisure, and workplace. Methods We analysed cross-sectional data on self-reported SHS exposure in 1059 non-daily smokers interviewed in the Cornellà Health Interview Survey Follow-up Study in 2002. We calculated age-adjusted prevalence rates and prevalence rate ratios of SHS exposure at home, at the workplace, during leisure time, and in any of these settings. Results The age-standardized prevalence rate of SHS exposure in any setting was 69.5% in men and 62.9% in women. Among men, 25.9% reported passive smoking at home, 55.1% during leisure time, and 34.0% at the workplace. Among women, prevalence rates in these settings were 34.1%, 44.3% and 30.1%, respectively. Overall exposure to SHS decreased with age in both men and women. In men, SHS exposure was related to marital status, physical activity, smoking, and alcohol intake. In women, SHS exposure was related to educational level, marital status, occupational status, self-perceived health, smoking-related illness, and alcohol intake. Conclusion The prevalence of SHS exposure in this population was high. The strongest association with exposure were found for age and occupational status in men, and age and educational level in women.

Chemical reactions in solvents and melts

CERN Document Server

Charlot, G

1969-01-01

Chemical Reactions in Solvents and Melts discusses the use of organic and inorganic compounds as well as of melts as solvents. This book examines the applications in organic and inorganic chemistry as well as in electrochemistry. Organized into two parts encompassing 15 chapters, this book begins with an overview of the general properties and the different types of reactions, including acid-base reactions, complex formation reactions, and oxidation-reduction reactions. This text then describes the properties of inert and active solvents. Other chapters consider the proton transfer reactions in

Acceleration of Intended Pozzolanic Reaction under Initial Thermal Treatment for Developing Cementless Fly Ash Based Mortar

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Yang-Hee Kwon

2017-02-01

Full Text Available Without using strong alkaline solution or ordinary Portland cement, a new structural binder consisting of fly ash and hydrated lime was hardened through an intensified pozzolanic reaction. The main experimental variables are the addition of silica fume and initial thermal treatment (60 °C for 3 days. A series of experiments consisting of mechanical testing (compressive and flexural strength, modulus of elasticity, X-ray diffraction, and measurements of the heat of hydration, pore structure, and shrinkage were conducted. These tests show that this new fly ash-based mortar has a compressive strength of 15 MPa at 91 days without any silica fume addition or initial thermal treatment. The strength increased to over 50 MPa based on the acceleration of the intensified pozzolanic reaction from the silica fume addition and initial thermal treatment. This is explained by a significant synergistic effect induced by the silica fume. It intensifies the pozzolanic reaction under thermal treatment and provides a space filling effect. This improved material performance can open a new pathway to utilize the industrial by-product of fly ash in cementless construction materials.

Crystal structure and magnetic properties of Y{sub 2}(Cu{sub 1−x}Mg{sub x}){sub 2}O{sub 5} obtained by SHS method

Energy Technology Data Exchange (ETDEWEB)

Gebrel, Z., E-mail: z_gebrel@yahoo.com; Blanusa, J.; Kusigerski, V.; Spasojevic, V.; Mrakovic, A.; Perovic, M.; Alqat, A.

2014-01-05

Highlights: • Y{sub 2}(Cu{sub 1−x}Mg{sub x}){sub 2}O{sub 5} solid solutions were synthesized for the first time by SHS method. • Ferromagnetic interactions are weakened by the induced structure changes. • Metamagnetism of the Y{sub 2}Cu{sub 2}O{sub 5} is preserved up to 15% of Mg concentration. • Significant influence of finite-size Cu–O chains is observed at low temperatures. -- Abstract: The single-phase polycrystalline samples of Y{sub 2}(Cu{sub 1−x}Mg{sub x}){sub 2}O{sub 5}, x = 0.0, 0.05, 0.15 were successfully synthesized by a modified self-propagating high temperature synthesis. Effects of Mg{sup +2} substitution for Cu{sup +2} in metamagnetic Y{sub 2}Cu{sub 2}O{sub 5} on its crystal structure and magnetic properties have been analyzed by X-ray diffraction and magnetic measurements performed within 2–300 K range. Mg doping was found to introduce small distortions in the main intradimmer superexchange paths so that ferromagnetic correlations decrease with Mg concentration. More significant impact of Cu substitution was found on the low temperature magnetism due to the breaking of infinite Cu–O chains. The formation of finite size chains introduces low temperature paramagnetic contribution and reduction in Néel temperature. Overall results give a strong indication that the antiferromagnetic ordering as well as metamagnetism persists up to the 15% of the Mg concentration.

Insights into the mechanisms on chemical reactions: reaction paths for chemical reactions

International Nuclear Information System (INIS)

Dunning, T.H. Jr.; Rosen, E.; Eades, R.A.

1987-01-01

We report reaction paths for two prototypical chemical reactions: Li + HF, an electron transfer reaction, and OH + H 2 , an abstraction reaction. In the first reaction we consider the connection between the energetic terms in the reaction path Hamiltonian and the electronic changes which occur upon reaction. In the second reaction we consider the treatment of vibrational effects in chemical reactions in the reaction path formalism. 30 refs., 9 figs