6 research outputs found
Chemical Science Research, Elementary School Children and Their Teachers Are More Closely Related than You May Imagine: The “I Bet You Did Not Know” Project
Topics associated with the chemical sciences form a significant
part of the curriculum in science at the primary school level in the
U.K. In this methodology paper, we demonstrate how a wide range of
research articles associated with the chemical sciences can be disseminated
to an elementary school audience and how children can carry out investigations
associated with cutting-edge research in the classroom. We discuss
how the Primary Science Teaching Trust’s (PSTT’s) “I
bet you did not know” (IBYDK) articles and their accompanying
Teacher Guides benefit children, primary (elementary) school teachers,
and other stakeholders including the researchers themselves. We define
three types of research articles; ones describing how children can
reproduce the research themselves without much adaptation, others
where children can mirror the research using similar methods, and
some where an analogy can be used to explain the research. We provide
exemplars of each type and some preliminary feedback on articles written
Chemical Science Research, Elementary School Children and Their Teachers Are More Closely Related than You May Imagine: The “I Bet You Did Not Know” Project
Topics associated with the chemical sciences form a significant
part of the curriculum in science at the primary school level in the
U.K. In this methodology paper, we demonstrate how a wide range of
research articles associated with the chemical sciences can be disseminated
to an elementary school audience and how children can carry out investigations
associated with cutting-edge research in the classroom. We discuss
how the Primary Science Teaching Trust’s (PSTT’s) “I
bet you did not know” (IBYDK) articles and their accompanying
Teacher Guides benefit children, primary (elementary) school teachers,
and other stakeholders including the researchers themselves. We define
three types of research articles; ones describing how children can
reproduce the research themselves without much adaptation, others
where children can mirror the research using similar methods, and
some where an analogy can be used to explain the research. We provide
exemplars of each type and some preliminary feedback on articles written
Quantum Yields for Photochemical Production of NO<sub>2</sub> from Organic Nitrates at Tropospherically Relevant Wavelengths
Absorption
cross-sections and quantum yields for NO<sub>2</sub> production (Φ<sub>NO<sub>2</sub></sub>) are reported for gaseous
methyl, ethyl, <i>n</i>-propyl, and isopropyl nitrate at
294 K. Absorption cross-sections in the wavelength range of 240–320
nm agree well with prior determinations. NO<sub>2</sub> quantum yields
at photoexcitation wavelengths of 290, 295, and 315 nm are unity within
experimental uncertainties for all of the alkyl nitrates studied and
are independent of bath gas (N<sub>2</sub>) pressure for total sample
pressures in the range of 250–700 Torr. When averaged over
all wavelengths and sample pressures, values of Φ<sub>NO<sub>2</sub></sub> are 1.03 ± 0.05 (methyl nitrate), 0.98 ±
0.09 (ethyl nitrate), 1.01 ± 0.04 (<i>n</i>-propyl
nitrate), and 1.00 ± 0.05 (isopropyl nitrate), with uncertainties
corresponding to 1 standard deviation. Absorption cross-sections for
ethyl nitrate, isopropyl nitrate, and two unsaturated dinitrate compounds,
but-3-ene-1,2-diyl dinitrate and (<i>Z</i>)-but-2-ene-1,4-diyl
dinitrate in acetonitrile solution, are compared to gas-phase values,
and over the wavelength range of 260–315 nm, the gas-phase
values are well-reproduced by dividing the liquid-phase cross-sections
by 2.0, 1.6, 1.7, and 2.2, respectively. Reasonable estimates of the
gas-phase absorption cross-sections for low-volatility organic nitrates
can therefore be obtained by halving the values for acetonitrile solutions.
The quantum yield for NO<sub>2</sub> formation from photoexcitation
of but-3-ene-1,2-diyl dinitrate at 290 nm is significantly lower than
those for the alkyl (mono) nitrates: a best estimate of Φ<sub>NO<sub>2</sub></sub> ≤ 0.25 is obtained from the experimental
measurements
Direct Measurements of Unimolecular and Bimolecular Reaction Kinetics of the Criegee Intermediate (CH<sub>3</sub>)<sub>2</sub>COO
The
Criegee intermediate acetone oxide, (CH<sub>3</sub>)<sub>2</sub>COO,
is formed by laser photolysis of 2,2-diiodopropane in the presence
of O<sub>2</sub> and characterized by synchrotron photoionization
mass spectrometry and by cavity ring-down ultraviolet absorption spectroscopy.
The rate coefficient of the reaction of the Criegee intermediate with
SO<sub>2</sub> was measured using photoionization mass spectrometry
and pseudo-first-order methods to be (7.3 ± 0.5) × 10<sup>–11</sup> cm<sup>3</sup> s<sup>–1</sup> at 298 K and
4 Torr and (1.5 ± 0.5) × 10<sup>–10</sup> cm<sup>3</sup> s<sup>–1</sup> at 298 K and 10 Torr (He buffer). These
values are similar to directly measured rate coefficients of <i>anti</i>-CH<sub>3</sub>CHOO with SO<sub>2</sub>, and in good
agreement with recent UV absorption measurements. The measurement
of this reaction at 293 K and slightly higher pressures (between 10
and 100 Torr) in N<sub>2</sub> from cavity ring-down decay of the
ultraviolet absorption of (CH<sub>3</sub>)<sub>2</sub>COO yielded
even larger rate coefficients, in the range (1.84 ± 0.12) ×
10<sup>–10</sup> to (2.29 ± 0.08) × 10<sup>–10</sup> cm<sup>3</sup> s<sup>–1</sup>. Photoionization mass spectrometry
measurements with deuterated acetone oxide at 4 Torr show an inverse
deuterium kinetic isotope effect, <i>k</i><sub>H</sub>/<i>k</i><sub>D</sub> = (0.53 ± 0.06), for reactions with SO<sub>2</sub>, which may be consistent with recent suggestions that the
formation of an association complex affects the rate coefficient.
The reaction of (CD<sub>3</sub>)<sub>2</sub>COO with NO<sub>2</sub> has a rate coefficient at 298 K and 4 Torr of (2.1 ± 0.5) ×
10<sup>–12</sup> cm<sup>3</sup> s<sup>–1</sup> (measured
with photoionization mass spectrometry), again similar to rate for
the reaction of <i>anti</i>-CH<sub>3</sub>CHOO with NO<sub>2</sub>. Cavity ring-down measurements of the acetone oxide removal
without added reagents display a combination of first- and second-order
decay kinetics, which can be deconvolved to derive values for both
the self-reaction of (CH<sub>3</sub>)<sub>2</sub>COO and its unimolecular
thermal decay. The inferred unimolecular decay rate coefficient at
293 K, (305 ± 70) s<sup>–1</sup>, is similar to determinations
from ozonolysis. The present measurements confirm the large rate coefficient
for reaction of (CH<sub>3</sub>)<sub>2</sub>COO with SO<sub>2</sub> and the small rate coefficient for its reaction with water. Product
measurements of the reactions of (CH<sub>3</sub>)<sub>2</sub>COO with
NO<sub>2</sub> and with SO<sub>2</sub> suggest that these reactions
may facilitate isomerization to 2-hydroperoxypropene, possibly by
subsequent reactions of association products
Outreach: Impact on Skills and Future Careers of Postgraduate Practitioners Working with the Bristol ChemLabS Centre for Excellence in Teaching and Learning
Postgraduate engagement in delivering outreach activities
is more
commonplace than it once was. However, the impact on postgraduate
students (typically studying for a Ph.D. degree) of participating
in the delivery of these outreach activities has rarely, if ever,
been recorded. The Bristol ChemLabS Outreach program has been running
for ca. 17 years, and in that time, many postgraduate students have
been involved (approximately 500), with around 250 typically for up
to 3 years. We sought to investigate the impact of outreach engagement
on postgraduate alumni who were involved in the program for over 3
years (32) and how the experiences and training of the outreach program
had impacted on their careers postgraduation. Thirty of the 32 postgraduates
engaged and ∼70% reported that their outreach experience had
influenced their decision making on future careers. Many respondents
reported that the skills and experiences gained through outreach participation
had contributed to success in applying for and interviewing at their
future employers. All respondents reported that outreach had helped
them to develop key skills that were valued in the workplace, specifically,
communication, teamwork, organizational skills, time planning, event
planning, and event management. Rather than a pleasant distraction
or an opportunity to supplement income, all participants noted that
they felt there were many additional benefits and that this was time
well spent. Outreach should not be viewed as a distraction to science
research but rather an important enhancement to it provided that the
program is well constructed and seeks to develop those delivering
the outreach activities
Outreach: Impact on Skills and Future Careers of Postgraduate Practitioners Working with the Bristol ChemLabS Centre for Excellence in Teaching and Learning
Postgraduate engagement in delivering outreach activities
is more
commonplace than it once was. However, the impact on postgraduate
students (typically studying for a Ph.D. degree) of participating
in the delivery of these outreach activities has rarely, if ever,
been recorded. The Bristol ChemLabS Outreach program has been running
for ca. 17 years, and in that time, many postgraduate students have
been involved (approximately 500), with around 250 typically for up
to 3 years. We sought to investigate the impact of outreach engagement
on postgraduate alumni who were involved in the program for over 3
years (32) and how the experiences and training of the outreach program
had impacted on their careers postgraduation. Thirty of the 32 postgraduates
engaged and ∼70% reported that their outreach experience had
influenced their decision making on future careers. Many respondents
reported that the skills and experiences gained through outreach participation
had contributed to success in applying for and interviewing at their
future employers. All respondents reported that outreach had helped
them to develop key skills that were valued in the workplace, specifically,
communication, teamwork, organizational skills, time planning, event
planning, and event management. Rather than a pleasant distraction
or an opportunity to supplement income, all participants noted that
they felt there were many additional benefits and that this was time
well spent. Outreach should not be viewed as a distraction to science
research but rather an important enhancement to it provided that the
program is well constructed and seeks to develop those delivering
the outreach activities