90 research outputs found
Petroleum-Collecting And Dispersing Chemicals For Cleaning Sea Surface From Thin Petroleum Slicks
Monoethylolamide, diethylolamide and triethanolamine ester synthesized by us
based on fish oil and their phosphate derivatives being surface-active and ecologically safe possess
a high capacity of petroleum collecting and dispersing. When introducing phosphate group, a
tendency to replacement of petroleum slick dispersing by its collection (accumulation into a spot)
is observed. Efficiency of the chemicals change depends on the type and concentration of ions in
the water. Such salts as NaCl, KI, KBr, and MgSO4 positively influence petroleum-collecting
activity whereas K2CO3 and NaHCO3 cause petroleum dispersing
Dynamics and Accounting of GHG Emissions in the World
The problem of climate change on the planet has been gradually forming since the middle of the 20th century. as the idea of a universal threat, to combat which humanity needs to unite and regulate the waste of resources. To do this, the problem of global climate change had to be introduced both into the political and economic agenda, and into the basic world system of values. Only then would climate rhetoric be able to influence political decisions and shape the way people live, as well as influence the global economy. But for this it is necessary to prove that humans are to blame for global climate change. The fact that nature is constantly changing, scientists knew until the middle of the 20th century. But it was believed that the reasons for this lie in the laws of long and short climatic cycles, and man has nothing to do with global changes. And this means that it is impossible to justify the reasons why the global community and individuals should change their behavior. That is, without substantiating the anthropogenic impact on global climate change, this topic cannot claim to be the central determinant of economic and political development
Brominated and Chlorinated Flame Retardants in Tree Bark from Around the Globe
Brominated and chlorinated flame retardants were measured
in about
40 samples of tree bark from 12 locations around the globe. The analytes
were polybrominated diphenyl ethers (PBDE), Dechlorane Plus (DP),
decabromodiphenylethane (DBDPE), hexabromocyclododecane (HBCD), hexabromobenzene
(HBB), pentabromoethylbenzene (PBEB), pentabromobenzene (PBBz), and
tetrabromo-<i>p</i>-xylene (pTBX). The highest concentrations
of these compounds were detected at an urban site in Downsview, Ontario,
Canada. Total PBDE and DP concentrations ranged from 2.1 to 190 ng/g
lipid weight and from 0.89 to 48 ng/g lipid weight, respectively.
Relatively high levels of DP (46 ± 4 ng/g lipid weight) were
found at a remote site at Bukit Kototabang in Indonesia. The concentrations
of total PBDE, DP, PBEB, and HBCD in the tree bark samples were significantly
associated with human population in the nearby areas (<i>r</i><sup>2</sup> = 0.21–0.56; <i>P</i> < 0.05). In
addition, the concentrations of total
PBDE and DP were significantly associated (<i>r</i><sup>2</sup> = 0.40–0.64; <i>P</i> <
0.05). with the corresponding atmospheric concentrations
of these compounds over a concentration range of 2–3 orders
of magnitude
Russia’s Climate Agenda: Responding to international calls
The problem of climate change on the planet has been gradually forming since the middle of the 20th century. as the idea of a universal threat, to combat which humanity needs to unite and regulate the waste of resources. To do this, the problem of global climate change had to be introduced both into the political and economic agenda, and into the basic world system of values. Only then would climate rhetoric be able to influence political decisions and shape the way people live, as well as influence the global economy. But for this it is necessary to prove that humans are to blame for global climate change. The fact that nature is constantly changing, scientists knew until the middle of the 20th century. But it was believed that the reasons for this lie in the laws of long and short climatic cycles, and man has nothing to do with global changes. And this means that it is impossible to justify the reasons why the global community and individuals should change their behavior. That is, without substantiating the anthropogenic impact on global climate change, this topic cannot claim to be the central determinant of economic and political development
NMR studies of some 4-hydroxy-2-methylacetophenone thiosemicarbazones in solutions
1518-1527Molecular dynamics of (E)-4-hydroxy-2-methylacetophenone
thiosemicarbazone and (E,E)-3-(5-bromo-2-hydroxyphenyl)-1-(4-hydroxy-2-methylphenyl)prop-2-en-1-one
thiosemicarbazone have been investigated in solution using NMR. The results confirm the presence of conformational
transitions in the <span style="mso-bidi-font-family:
" times="" new="" roman";mso-ansi-language:az-latin"="" lang="AZ-LATIN">investigated molecules. The rotational barrier energy for the conformational transitions
has been calculated.
</span
Air is Still Contaminated 40 Years after the Michigan Chemical Plant Disaster in St. Louis, Michigan
The Michigan Chemical (also known
as Velsicol Chemical) plant located
in St. Louis, Michigan operated from 1936–1978. During this
time, the plant manufactured polybrominated biphenyls (PBBs), hexabromobenzene
(HBB), 1,1,1-trichloro-2,2-<i>bis</i>(4-chlorophenyl) ethane
(DDT), and <i>tris</i>(2,3-dibromopropyl) phosphate (TDBPP),
among other products. Due to widespread PBB contamination of Michigan,
the plant eventually became a Superfund site, and despite years of
cleanup activities, many of the compounds can still be found in the
local ecosystem. To investigate the current atmospheric levels and
to determine their spatial distributions, we collected tree bark samples
from around Michigan and measured the concentrations of these pollutants.
For comparison, other organic pollutants, such as polybrominated diphenyl
ethers (PBDEs) and organophosphate esters (OPEs), which were not manufactured
at the Michigan Chemical plant, were also measured in the same tree
bark samples. Our results show levels of PBBs, DDT, and HBB in tree
bark collected within 10 km of the Velsicol Superfund site (43, 477,
and 108 ng/g lipid wgt., respectively) are 1–2 orders of magnitude
higher than at sites located more than 10 km from the site (0.36,
28, and 0.36 ng/g lipid wgt., respectively). Levels of PBDEs and OPEs
did not depend on distance from St. Louis. This is the first study
on the atmospheric distribution of these chemicals around the Superfund
site
Revised Temporal Trends of Persistent Organic Pollutant Concentrations in Air around the Great Lakes
The concentrations of polychlorinated
biphenyls, polycyclic aromatic
hydrocarbons (PAH), and several chlorinated insecticides in air have
been measured every 12 days since 1991 at several sites on the shores
of the North American Great Lakes. We give here the geometric mean
concentrations for each of these compounds for each year and at each
site. In most cases, these concentrations have been measured in both
the vapor and particle phases; if concentrations were available for
both phases, the two concentrations were summed, and those data are
presented here. Assuming a first-order rate model for these data,
we have calculated the time it takes for the concentrations to decrease
by half. For most compounds, the halving times are the same for the
vapor phase and for the vapor and particle phase concentrations summed
together. The halving times are generally not distinguishable among
the sites. Overall, the observed halving times are 8–15 years,
except for that of lindane, which is disappearing with a halving time
of ∼4 years
- …