51 Disintegration of 12C nuclei by 700–1500 MeV photons - Nuclear Physics A,...Cristian Randieri PhD
Disintegration of 12C nuclei by 700–1500 MeV photons - Elsevier Science, Nuclear Physics A, August 2015, Vol. 940, pp. 264-278, DOI: 10.1016/j.nuclphysa.2015.05.001
di V. Nedorezov, A. D’Angelo, O. Bartalini, V. Bellini, M. Capogni, L.E. Casano, M. Castoldi, F. Curciarello, V. De Leo, J.-P. Didelez, R. Di Salvo, A. Fantini, D. Franco, G. Gervino, F. Ghio, G. Giardina, B. Girolami, A. Giusa, A. Lapik, P. Levi Sandri, F. Mammoliti, G. Mandaglio, M. Manganaro, D. Moricciani, A. Mushkarenkov, I. Pshenichnov, C. Randieri, N. Rudnev, G. Russo, C. Schaerf, M. L. Sperduto, M.-C. Sutera, A. Turinge, V. Vegna, I. Zonta (2015)
Abstract
Disintegration of 12C nuclei by tagged photons of 700–1500 MeV energy at the GRAAL facility has been studied by means of the LAGRANγE detector with a wide angular acceptance. The energy and momentum distributions of produced neutrons and protons as well as their multiplicity distributions were measured and compared with corresponding distributions calculated with the RELDIS model based on the intranuclear cascade and Fermi break-up models. It was found that eight fragments are created on average once per about 100 disintegration events, while a complete fragmentation of 12C into 12 nucleons is observed typically only once per 2000 events. Measured multiplicity distributions of produced fragments are well described by the model. The measured total photoabsorption cross section on 12C in the same energy range is also reported.
A.A. Carmona-Martínez, E. Trably, N. Bernet. 2015. Direct microbial electrosynthesis or H2 mediated microbial synthesis of acetate? Presented at the Fifth international meeting on microbial electrochemistry and technologies, Arizona (USA), October 1st – 4th, 2015: http://www.ismet2015.org/
51 Disintegration of 12C nuclei by 700–1500 MeV photons - Nuclear Physics A,...Cristian Randieri PhD
Disintegration of 12C nuclei by 700–1500 MeV photons - Elsevier Science, Nuclear Physics A, August 2015, Vol. 940, pp. 264-278, DOI: 10.1016/j.nuclphysa.2015.05.001
di V. Nedorezov, A. D’Angelo, O. Bartalini, V. Bellini, M. Capogni, L.E. Casano, M. Castoldi, F. Curciarello, V. De Leo, J.-P. Didelez, R. Di Salvo, A. Fantini, D. Franco, G. Gervino, F. Ghio, G. Giardina, B. Girolami, A. Giusa, A. Lapik, P. Levi Sandri, F. Mammoliti, G. Mandaglio, M. Manganaro, D. Moricciani, A. Mushkarenkov, I. Pshenichnov, C. Randieri, N. Rudnev, G. Russo, C. Schaerf, M. L. Sperduto, M.-C. Sutera, A. Turinge, V. Vegna, I. Zonta (2015)
Abstract
Disintegration of 12C nuclei by tagged photons of 700–1500 MeV energy at the GRAAL facility has been studied by means of the LAGRANγE detector with a wide angular acceptance. The energy and momentum distributions of produced neutrons and protons as well as their multiplicity distributions were measured and compared with corresponding distributions calculated with the RELDIS model based on the intranuclear cascade and Fermi break-up models. It was found that eight fragments are created on average once per about 100 disintegration events, while a complete fragmentation of 12C into 12 nucleons is observed typically only once per 2000 events. Measured multiplicity distributions of produced fragments are well described by the model. The measured total photoabsorption cross section on 12C in the same energy range is also reported.
A.A. Carmona-Martínez, E. Trably, N. Bernet. 2015. Direct microbial electrosynthesis or H2 mediated microbial synthesis of acetate? Presented at the Fifth international meeting on microbial electrochemistry and technologies, Arizona (USA), October 1st – 4th, 2015: http://www.ismet2015.org/
Effect of Swift Heavy Ion irradiation on Optical properties of Poly vinyliden...ijtsrd
The lithium ion (50 MeV) having fluence range of 1x1011 ions/cm2 to 3x1012 ions/cm2 induced poly vinylidene chloride (PVDC) films have been examined using UV-Visible technique. The shift in optical absorption edge in irradiated PVDC was associated with the decrease in optical band gap energy. The noticeable characteristic peak was detected due to UV-Vis analysis, in lithium irradiated samples of PVDC at highest fluence. Kusam Devgan"Effect of Swift Heavy Ion irradiation on Optical properties of Poly vinylidene chloride (PVDC) Films" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-1 | Issue-5 , August 2017, URL: http://www.ijtsrd.com/papers/ijtsrd2244.pdf http://www.ijtsrd.com/physics/other/2244/effect-of-swift-heavy-ion-irradiation-on-optical-properties-of-poly-vinylidene-chloride-pvdc-films/kusam-devgan
Synthesis and Characterization of Elastin-Like PolypeptidesJustin Coleman
Elastin-Like Polypeptides (ELP) are class of biopolymers that are composed of a repeating pentapeptide sequence that mimics mammalian elastin with the structure VPGXG. ELP has a Low Critical Solution Temperature (LCST) which enables it to dissolve in solution at lower temperatures and above the LCST the ELP aggregates into insoluble coacervates. This work makes use of a robust chemistry to attach various biocompatible Lewis bases to the ELP molecules. This will allow the ELP to act as an electron donor to specific types of atoms that are electron deficient. These atoms will act as coordination centers for the ELP molecules and allow them to exhibit certain advantageous and tailorable properties. This work will explore how stereochemistry, and different electron deficient molecules change the behavior of ELP and its transition temperature. Nanodrop UV vis will be used to explore how changing the electron deficient molecules effects the electrons in the ELP and thus the UV wavelength absorbance. FT-IR will demonstrate the change in functional groups after the reactions have occurred. Lastly, dynamic light scattering will be used to show a change in transition temperature of the ELP when exposed to different variables.
Using natural abundance of isotopes to investigate chemical reaction mechanismsDaniel Morton
The natural abundance of isotopes of a chemical element can provide detailed information about the mechanism of a large range of chemical reactions. Small heavy-atom and secondary hydrogen kinetic isotope effects (KIEs) can be measured with high-precision, simultaneously determining multiple small KIEs at natural abundance using NMR techniques.
Contributed by: John Gipson and Victoria Russell (Undergraduate students)
University of Utah, 2014
Self-Powered Biosensor for Ascorbic Acid with a Prussian Blue Electrochromic ...DrMJN
We have prepared electrodes modified with either carbon nanoparticles or vertically aligned carbon nanotubes for AA oxidation. We show that by connecting the CNP anode to a Prussian blue electrochromic display we can create a truly self-powered sensor that does not require any external power source for determining the concentration of AA in a sample.
Effect of Swift Heavy Ion irradiation on Optical properties of Poly vinyliden...ijtsrd
The lithium ion (50 MeV) having fluence range of 1x1011 ions/cm2 to 3x1012 ions/cm2 induced poly vinylidene chloride (PVDC) films have been examined using UV-Visible technique. The shift in optical absorption edge in irradiated PVDC was associated with the decrease in optical band gap energy. The noticeable characteristic peak was detected due to UV-Vis analysis, in lithium irradiated samples of PVDC at highest fluence. Kusam Devgan"Effect of Swift Heavy Ion irradiation on Optical properties of Poly vinylidene chloride (PVDC) Films" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-1 | Issue-5 , August 2017, URL: http://www.ijtsrd.com/papers/ijtsrd2244.pdf http://www.ijtsrd.com/physics/other/2244/effect-of-swift-heavy-ion-irradiation-on-optical-properties-of-poly-vinylidene-chloride-pvdc-films/kusam-devgan
Synthesis and Characterization of Elastin-Like PolypeptidesJustin Coleman
Elastin-Like Polypeptides (ELP) are class of biopolymers that are composed of a repeating pentapeptide sequence that mimics mammalian elastin with the structure VPGXG. ELP has a Low Critical Solution Temperature (LCST) which enables it to dissolve in solution at lower temperatures and above the LCST the ELP aggregates into insoluble coacervates. This work makes use of a robust chemistry to attach various biocompatible Lewis bases to the ELP molecules. This will allow the ELP to act as an electron donor to specific types of atoms that are electron deficient. These atoms will act as coordination centers for the ELP molecules and allow them to exhibit certain advantageous and tailorable properties. This work will explore how stereochemistry, and different electron deficient molecules change the behavior of ELP and its transition temperature. Nanodrop UV vis will be used to explore how changing the electron deficient molecules effects the electrons in the ELP and thus the UV wavelength absorbance. FT-IR will demonstrate the change in functional groups after the reactions have occurred. Lastly, dynamic light scattering will be used to show a change in transition temperature of the ELP when exposed to different variables.
Using natural abundance of isotopes to investigate chemical reaction mechanismsDaniel Morton
The natural abundance of isotopes of a chemical element can provide detailed information about the mechanism of a large range of chemical reactions. Small heavy-atom and secondary hydrogen kinetic isotope effects (KIEs) can be measured with high-precision, simultaneously determining multiple small KIEs at natural abundance using NMR techniques.
Contributed by: John Gipson and Victoria Russell (Undergraduate students)
University of Utah, 2014
Self-Powered Biosensor for Ascorbic Acid with a Prussian Blue Electrochromic ...DrMJN
We have prepared electrodes modified with either carbon nanoparticles or vertically aligned carbon nanotubes for AA oxidation. We show that by connecting the CNP anode to a Prussian blue electrochromic display we can create a truly self-powered sensor that does not require any external power source for determining the concentration of AA in a sample.
Photocatalysis has now become an emerging scientific discipline due to its interdisciplinary nature. The wide range of research groups is now working on different aspects of photocatalysis worldwide. It is one of the technology the world looking forward to address environmental as well as energy related issues. Hence we can call it as a technology for the future or a dream technology! We need to overcome too many hurdles to implement this technology in real life. Like any other discipline there is a lot of misunderstanding/ misconceptions in photocatalysis.
Most frequently cited article in the field of photocatalysis is by Fujishima and Honda published in 1972 in nature and it has been cited by the photocatalytic community as an origin of photocatalysis. This aspect is not true at all. This article cannot be the origin of photocatalysis. This article only promoted photocatalytic studies. The author itself, actually, started a research career in the “boom” of photocatalytic studies initiated by this article.
This small presentation aims to deliver some misconceptions like above in photocatalysis. The entire presentation is based on different personal commentaries written by Jean Mary Hermann and Bunsho Ohtani. Some recent articles relevant to the topic are collected by the speaker itself and put it in one platform.
Los días 8 y 9 de octubre de 2014, la Fundación Ramón Areces acogió el Simposio Internacional 'Química: respuestas para una vida mejor', organizado en colaboración con la Fundación General CSIC. Su finalidad fue ofrecer a los participantes una visión atractiva de la química moderna que sirva de base al desarrollo de nuevas respuestas para una sociedad en rápida evolución.
Novel composite electrodes:Preparation and application to the electroanalytic...Université de Dschang
M. Tchieno Melataguia Francis Merlin a soutenu une thèse de Doctorat/Phd en Chimie Inorganique ce 06 juin 2016 dans la salle des conférences de l'Université de Dschang. A l'issue de cette soutenance devant le jury présidé par le Prof. Emmanuel Ngameni lui a décerné la mention très honorable à l'unanimité de ses membres.
56.Synthesis, Characterization and Antibacterial activity of iron oxide Nanop...
Anthony_M_ACS_NewOrleans_GM_final__
1. Possible Reaction Pathways and Species Identified
via Mass Spectrometry
Results
Investigation of Low Temperature Oxidation Reactions of
2-Phenylethanol Using Photoionization Mass Spectrometry
Anthony Medrano,1 Magaly Wooten,1 Joseph Czekner,1 David L. Osborn,2 Craig A. Taatjes,2 Giovanni Meloni1,*
1) Department of Chemistry, University of San Francisco, San Francisco, CA 94117; 2) Combustion Research Facility, Sandia National Laboratories, Livermore, CA 94551
Abstract
In search of economical, alternative biofuels, current research investigates the combustion
properties of 2-phenylethanol (2PE). Oxidation reactions of 2-phenylethanol are initiated using
248 nm photolysis of Cl2 in a quartz reaction chamber at temperatures of 298 and 550 K and a
pressure of 4 Torr. Products are identified using the multiplex photoionization mass
spectrometer coupled to the synchrotron radiation from the Advanced Light Source (ALS) in
Berkeley, CA. The reaction is compared at the two temperatures and preliminary results are
presented.
Introduction
• Concerns in global energy and environment lead to interest in finding alternative fuel produced
from renewable resources1-4
• Compared with ethanol, 2-phenylethanol offers advantages as a gasoline substitute because of its
higher energy density and lower hygroscopicity2
• 2-Phenylethanol is soluble in water and therefore may be washed out of the atmosphere by rain5
• 2-Phenylethanol is readily biodegradable6, has a low toxicity level,7 and is commonly used in
fragrances7
Conclusions
• The aromatic ring remains intact.
• All chemistry occurs on the side chain.
• Phenylacetaldehyde and 2-phenylethenol undergo decomposition, which explains the occurrence
of products with lower mass-to-charge ratios.
• For reactions with oxygen at 550 K compared to those at 298 K, there is a decrease in products
with lower a m/z and an increase in products with a higher m/z.
• For reactions without oxygen at 550 K compared to those at 298 K, products with a lower m/z
show no formation or similar concentration and for products with a higher m/z, there is a
significant increase in concentration at 550K.
• Branching fractions will be determined after more products have been identified.
References
1. Conner, M.; Liao, J. Appl. Envir. Microbiol. 2008, 74, 18, 5769–5775.
2. Conner, M.; Cann, A.; Liao, J. Appl. Microbiol. Biot. 2010, 86, 1155-1164.
3. Atsumi, S; Hanai, T; Liao, J. Nature. 2008, 451, 86-89.
4. Lee, S; Chou, H; Ham, T; Lee, T; Keasling J. Curr Opin Biotech. 2010, 19, 556-563
5. Daubert TE, Danner RP; Data Compilation Tables of Properties of Pure Compounds NY, NY: Amer Inst for Phys Prop Data (1989) -vp
6. Chemicals Inspection and Testing Institute; Biodegradation and bioaccumulation data of existing chemicals based on the CSCL Japan. Japan Chemical Industry
Ecology-Toxicology and Information Center. p. 5-21, ISBN 4-89074-101-1 (1992)]
7. Etschmann, M. M. W.; Bluemke, W.; Sell, D.; Shrader, J. Biotechnological production of 2-phenylethanol, Appl. Microbiol. Biotechnol. , 2002, 59, 1-8.
8. Klasinc, L.; Kovac, B.; Gusten, H., Photoelctron spectra of acenes. Electronic structure and substituent effects, Pure & Appl. Chem., 1983, 55, 289-298.
9. Dallinga, J.W.; Nibbering, N.M.M.; Louter, G.J., Formation and structure of [C8H8O]+ ions, generated from gas phase ions of phenylcyclopropylcarbinol and 1-phenyl-1-
(hydroxymethyl)cyclopropane, Org. Mass Spectrom., 1981, 16, 4.
10. Gaussian 09, Revision A.1, Frisch, M. J.; Trucks, G. W.; Schlegel, H. B.; Scuseria, G. E.; Robb, M. A.; Cheeseman, J. R.; Scalmani, G.; Barone, V.; Mennucci, B.; Petersson,
G. A.; Nakatsuji, H.; Caricato, M.; Li, X.; Hratchian, H. P.; Izmaylov, A. F.; Bloino, J.; Zheng, G.; Sonnenberg, J. L.; Hada, M.; Ehara, M.; Toyota, K.; Fukuda, R.;
Hasegawa, J.; Ishida, M.; Nakajima, T.; Honda, Y.; Kitao, O.; Nakai, H.; Vreven, T.; Montgomery, Jr., J. A.; Peralta, J. E.; Ogliaro, F.; Bearpark, M.; Heyd, J. J.; Brothers, E.;
Kudin, K. N.; Staroverov, V. N.; Kobayashi, R.; Normand, J.; Raghavachari, K.; Rendell, A.; Burant, J. C.; Iyengar, S. S.; Tomasi, J.; Cossi, M.; Rega, N.; Millam, J. M.;
Klene, M.; Knox, J. E.; Cross, J. B.; Bakken, V.; Adamo, C.; Jaramillo, J.; Gomperts, R.; Stratmann, R. E.; Yazyev, O.; Austin, A. J.; Cammi, R.; Pomelli, C.; Ochterski, J. W.;
Martin, R. L.; Morokuma, K.; Zakrzewski, V. G.; Voth, G. A.; Salvador, P.; Dannenberg, J. J.; Dapprich, S.; Daniels, A. D.; Farkas, Ö.; Foresman, J. B.; Ortiz, J. V.;
Cioslowski, J.; Fox, D. J. Gaussian, Inc., Wallingford CT, 2009.
Acknowledgments
We want to thank Joseph Czeckner and Magaly Wooten, graduate students in the Chemistry Master’s program at the
University of San Francisco, for their continued assistance. We acknowledge the American Chemical Society – Petroleum
Research Fund Grant # 51170 UNI6, the University of San Francisco Faculty Development Fund for financial support,
the usage of the chemistry computer cluster at the University of San Francisco supported by professors Claire Castro
and William Karney. The Advanced Light Source is supported by the Director, Office of Science, Office of Basic Energy
Sciences, Materials Sciences Division, of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231 at
Lawrence Berkeley National Laboratory.
Apparatus
Data was collected in the 298-550 K temperature range using a laser photolysis reactor coupled to
multiplexed chemical kinetics photoionization mass spectrometer, which allows simultaneous
detection of the formation and depletion of multiple species during photolytically initiated
reactions. Oxidation is initiated by chlorine radicals produced by 351 nm photolysis of chloride.
(351 nm)
Reaction species were ionized by the tunable VUV synchrotron radiation produced at the
Advanced Light Source of Lawrence Berkeley National Laboratory8.
Figure 1. Schematic view of the reactor tube and time-resolved mass spectrometer using the
tunable VUV radiation of the Advanced Light Source at Lawrence Berkeley National Laboratory.
m
Dm
~ 2000
50 kHz
repetition
rate
Excimer laser
photolysis
hn
+150 V
-150 V
-4,000 V
R
E
A
Detector Detector
hν
0 V
0 V
+150 V
-150 V
-4,000 V
DC ion
optics
Dv⊥ ~ 0
P = 1 – 10 torr
T = 300 – 1000 K
push
pull
Ion
Formation
Ion
Extraction
Figure 2. (a) Mass-to-charge ratio (m/z) vs. photon energy (eV) 2D-slice for 2PE + Cl· + O2.
(b) m/z vs time (ms) 2D-slice for 2PE + Cl· + O2. (c) Experimental PIE curve of m/z = 106 with
benzaldehyde spectrum superimposed. (d) Experimental PIE curve of m/z = 120 with
phenylacetaldehyde spectrum superimposed. (e) Kinetic time traces of 2PE (multiplied by -1), m/z =
106, and m/z = 120. The data were collected from the experiments which occurred at 298 K with
oxygen at the ALS in November of 2011.
(a)
(b)
(c) (d)
Specific Aims
• To determine the products of 2PE and chlorine with and without oxygen at 298 and at 550 K:
+ O2 + Cl· → ?
+ Cl· → ?
2-Phenylethanol
M/Z Product Structure
Observed with O2 at
Specified Temperatures
(K)
Observed without O2 at
Specified Temperatures
(K)
30 Formaldehyde 298 / 550 298 / 550
32 Methanol Not observed 298
44 Acetaldehyde 298 / 550 298
46 Ethanol 298 Not observed
78 Benzene 298 / 550 298 / 550
92 Toluene 298 / 550 298 / 550
104 Styrene 550 298 / 550
106 Benzaldehyde 298 / 550 298 / 550
120 Phenylacetaldehyde 298 / 550 298 / 550
(e)
+
O2
O2O2
2O2
O2
Decomposition
O2
O2
+
+
+
+
+
+ +
+
+
O2
Decomposition
H shift
H shift
O2
O2
+
+
Decomposition
+
x 2