Electron Scattering By Methanol And Ethanol: A Joint Theoretical- Experimental Investigation

We present a joint theoretical-experimental study on electron scattering by methanol (CH 3OH) and ethanol (C 2H 5OH) in a wide energy range. Experimental differential, integral and momentum-transfer cross sections for elastic electron scattering by ethanol are reported in the 100-1000 eV energy range. The experimental angular distributions of the energy-selected electrons are measured and converted to absolute cross sections using the relative flow technique. Moreover, elastic, total, and total absorption cross sections for both alcohols are calculated in the 1-500 eV energy range. A complex optical potential is used to represent the dynamics of the electron-alcohol interaction, whereas the scattering equations are solved iteratively using the Padé's approximant technique. Our calculated data agree well with those obtained using the Schwinger multichannel method at energies up to 20 eV. Discrepancies at high energies indicate the importance of absorption effects, included in our calculations. In general, the comparison between our theoretical and experimental results, as well as with other experimental data available in the literature, also show good agreement. Nevertheless, the discrepancy between the theoretical and experimental total cross sections at low incident energies suggests that the experimental cross sections measured using the transmission technique for polar targets should be reviewed. © 2012 American Institute of Physics.13611Khakoo, M.A., Blumer, J., Keane, K., Campbell, C., Silva, H., Lopes, M.C.A., Winstead, C., Bettega, M.H.F., Low-energy electron scattering from methanol and ethanol (2008) Physical Review A - Atomic, Molecular, and Optical Physics, 77 (4), p. 042705. , http://oai.aps.org/oai?verb=GetRecord&Identifier=oai:aps.org: PhysRevA.77.042705&metadataPrefix=oai_apsmeta_2, DOI 10.1103/PhysRevA.77.042705Silva, D.G.M., Tejo, T., Muse, J., Romero, D., Khakoo, M.A., Lopes, M.C.A., (2010) J. Phys. B, 43, p. 015201. , 10.1088/0953-4075/43/1/015201Schmieder, F., (1930) Z. Elektrochem. Angew. Phys. Chem., 36, p. 700Mori, S., Katayama, Y., Sueoka, O., (1985) At. Coll. Res. Jpn. Prog. Rep., 11, p. 19Szmytkowski, C., Krzysztofowicz, A.M., (1995) J. Phys. B, 28, p. 4191. , 10.1088/0953-4075/28/19/014Srivastava, S.K., Krishnakumar, E., Fucaloro, A.F., Note, T.V., (1996) J. Geophys. Res., 101, p. 26155. , doi: 10.1029/96JE02471Duri, N., Cadez, I., Kurepa, M., (1989) Fizika (Zagreb), 21, p. 339Rejoub, R., Morton, C.D., Lindsay, B.G., Stebbings, R.F., (2003) J. Chem. Phys., 118, p. 1756. , 10.1063/1.1531631Sugohara, R.T., Homem, M.G.P., Sanches, I.P., De Moura, A.F., Lee, M.T., Iga, I., (2011) Phys. Rev. A, 83, p. 032708. , 10.1103/PhysRevA.83.032708Bouchiha, D., Gorfinkiel, J.D., Caron, L.G., Sanche, L., Low-energy electron collisions with methanol (2007) Journal of Physics B: Atomic, Molecular and Optical Physics, 40 (6), pp. 1259-1270. , DOI 10.1088/0953-4075/40/6/016, PII S0953407507349626, 016Joshipura, K.N., Vinodkumar, M., (1999) Eur. Phys. J. D, 5, p. 229. , 10.1007/s100500050277Vinodkumar, M., Limbachiya, C., Joshipura, K.N., Vaishnav, B., Gangopadhyay, S., (2008) J. Phys.: Conf. Ser., 115, p. 012013. , 10.1088/1742-6596/115/1/012013Kimura, M., Sueoka, O., Hamada, A., Itikawa, Y., (2000) Adv. Chem. Phys., 111, p. 537. , 10.1002/SERIES2007Zecca, A., Chiari, L., Sarkar, A., Nixon, K.L., Brunger, M.J., (2008) Phys. Rev. A, 78, p. 022703. , 10.1103/PhysRevA.78.022703Iga, I., Lee, M.T., Homem, M.G.P., MacHado, L.E., Brescansin, L.M., (2000) Phys. Rev. A, 61, p. 227081. , 10.1103/PhysRevA.61.022708Rawat, P., Iga, I., Lee, M.T., Brescansin, L.M., MacHado, L.E., Homem, M.G.P., (2003) Phys. Rev. A, 68, p. 052711. , 10.1103/PhysRevA.68.052711Homem, M.G.P., Sugohara, R.T., Sanches, I.P., Lee, M.T., Iga, I., (2009) Phys. Rev. A, 80, p. 032705. , 10.1103/PhysRevA.80.032705Srivastava, S.K., Chutjian, A., Trajmar, S., (1975) J. Chem. Phys., 63, p. 2659. , 10.1063/1.431659Nickel, J.C., Zetner, P.W., Shen, G., Trajmar, S., (1989) J. Phys. E: J. Sci. Instrum., 22, p. 730. , 10.1088/0022-3735/22/9/010Homem, M.G.P., Iga, I., Sugohara, R.T., Sanches, I.P., Lee, M.T., (2011) Rev. Sci. Instrum., 82, p. 01319. , 10.1063/1.3525799Jansen, R.H.J., De Heer, F.J., Luyken, H.J., Van Wingerden, B., Blaauw, H.J., (1976) J. Phys. B, 9, p. 185. , 10.1088/0022-3700/9/2/009Dubois, R.D., Rudd, M.E., (1976) J. Phys. B, 9, p. 2657. , 10.1088/0022-3700/9/15/016Gianturco, F.A., Lucchese, R.R., Sanna, N., (1995) J. Chem. Phys., 102, p. 5743. , 10.1063/1.469305Rawat, P., Homem, M.G.P., Sugohara, R.T., Sanches, I.P., Iga, I., De Souza, G.L.C., Dos Santos, A.S., Lee, M.-T., (2010) J. Phys. B, 43, p. 22502. , 10.1088/0953-4075/43/22/225202De Souza, G.L.C., Santos, A.S., Lee, M.-T., MacHado, L.E., Brescansin, L.M., Lucchese, R.R., Sugohara, R.T., Iga, I., (2010) Phys. Rev. A, 82, p. 012709. , 10.1103/PhysRevA.82.012709Padial, N.T., Norcross, D.W., (1984) Phys. Rev. A, 29, p. 1742. , 10.1103/PhysRevA.29.1742http://cccbdb.nist.gov, Computational Chemistry Comparison and Benchmark Database - NISTLee, M.-T., Iga, I., Machado, L.E., Brescansin, L.M., Castro, E.A., Sanches, I.P., De Souza, G.L.C., Improvement on the complex optical potential for electron collisions with atoms and molecules (2007) Journal of Electron Spectroscopy and Related Phenomena, 155 (1-3), pp. 14-20. , DOI 10.1016/j.elspec.2006.10.009, PII S0368204806001265, Scattering, Coincidence and Absorption Studies of Molecules SCASMStaszewska, G., Schwenke, D.W., Thirumalai, D., Truhlar, D.G., (1983) Phys. Rev. A, 28, p. 2740. , 10.1103/PhysRevA.28.2740Hara, S., (1967) J. Phys. Soc. Jpn., 22, p. 710. , 10.1143/JPSJ.22.710Schmidt, M.W., Baldridge, K.K., Boatz, J.A., Elbert, S.T., Gordon, M.S., Jensen, J.H., Koseki, S., Montgomery, J.A., (1993) J. Comput. Chem., 14, p. 1347. , 10.1002/jcc.540141112(1992) Handbook of Chemistry and Physics, , 73rd ed., edited by David R. Lide (CRC Press, Boca Raton)Lee, M.-T., Iga, I., Brescansin, L.M., MacHado, L.E., MacHado, F.B.C., (2002) Phys. Rev. A, 66, p. 012720. , 10.1103/PhysRevA.66.012720Rawat, P., Iga, I., Lee, M.-T., Brescansin, L.M., Homem, M.G.P., MacHado, L.E., (2003) Phys. Rev. A, 68, p. 052711. , 10.1103/PhysRevA.68.052711Ibnescu, B.C., May, O., Monney, A., Allan, M., (2007) Phys. Chem. Chem. Phys., 9, p. 3163. , 10.1039/b704656aJoshipura, K.N., Vinodkumar, M., Patel, P.M., (2000) J. Phys. B, 34, p. 509. , 10.1088/0953-4075/34/4/30

Arremessar por cima do ombro e a distância percorrida pelo implemento Overarm throw and the distance traveled by the implement

A habilidade de arremessar por cima do ombro tem sido bastante estudada, observando-se a velocidade do implemento, porém enquanto muitas tarefas têm como objetivo arremessar o mais longe possível, a distância percorrida pelo objeto ainda não tem sido investigada. O objetivo deste estudo foi verificar se existe relação entre o estágio de desenvolvimento motor nesta habilidade e a distância percorrida pelo implemento e observar diferenças entre os gêneros masculino e feminino; 50 crianças, com idade entre 7-8 anos, de ambos os gêneros, procedentes de Piracicaba - SP foram analisadas enquanto arremessavam uma bola de tênis de campo, o mais longe possível. Cada criança realizou três arremessos intercalados e foi filmada com duas câmeras mini DV, tanto em vista lateral quanto posterior, enquanto arremessava. O nível de desenvolvimento das crianças foi classificado, utilizando-se uma sequência de desenvolvimento e a distância percorrida pela bola foi registrada. Foi encontrada correlação significativa entre o nível do desenvolvimento e a distância atingida. Diferenças entre os gêneros foram observadas: os meninos encontravam-se em níveis desenvolvimentais mais avançados em todas as ações e alcançaram maiores distâncias. Assim, o nível de desenvolvimento desta habilidade mostrou-se importante para o alcance de seu objetivo (arremessar mais longe). Sugere-se que o nível de habilidade é influenciado pelo meio ambiente e que oportunidades de movimento devem ser providenciadas para auxiliar o desenvolvimento integral da criança.<br>Overarm throwing skill has been widely studied regarding the farthest throwing distance analysing the velocity of the implement; however the object's distance has not been investigated. The aim of this study was to verify if there is a relationship between the skill development and the distance reached by the object and to observe differences between genders. Fifty children, ages 7-8 years, both genders, from Piracicaba - SP, were analyzed while throwing a tennis ball as far as they could. Each child had three attempts. They were filmed with two mini DV cameras, from both side and rear views while performing. Children's movements were categorized using a developmental sequence and the distance covered by the ball was register. A positive correlation was found between the developmental level and the ball distance. Gender differences were observed; boys were in a more advanced levels in all actions and had farther throwing distances. So, developmental level of this skill was important to reach the task goal (throwing as far as possible). It is suggested that skill level is influenced by the environment and movement opportunities must be provided in order to help the children's global development