33 research outputs found
Improved Alternatives for Estimating In-Use Material Stocks
Determinations
of in-use material stocks are useful for exploring
past patterns and future scenarios of materials use, for estimating
end-of-life flows of materials, and thereby for guiding policies on
recycling and sustainable management of materials. This is especially
true when those determinations are conducted for individual products
or product groups such as āautomobilesā rather than
general (and sometimes nebulous) sectors such as ātransportationā.
We propose four alternatives to the existing topādown and bottomāup
methods for estimating in-use material stocks, with the choice depending
on the focus of the study and on the available data. We illustrate
with aluminum use in automobiles the robustness of and consistencies
and differences among these four alternatives and demonstrate that
a suitable combination of the four methods permits estimation of the
in-use stock of a material contained in all products employing that
material, or in-use stocks of different materials contained in a particular
product. Therefore, we anticipate the estimation in the future of
in-use stocks for many materials in many products or product groups,
for many regions, and for longer time periods, by taking advantage
of methodologies that fully employ the detailed data sets now becoming
available
Anthropogenic Cycles of the Elements: A Critical Review
A cycle is the quantitative characterization of the flows
of a
specific material into, within, and from a given system. An anthropogenic
elemental cycle can be static (for a point in time) or dynamic (over
a time interval). The about 350 publications collected for this review
contain a total of 1074 individual cycle determinations, 989 static
and 85 dynamic, for 59 elements; more than 90% of the publications
have appeared since 2000. The cycles are of varying quality and completeness,
with about 80% at country- or territory-level, addressing 45 elements,
and 5% at global-level, addressing 30 elements. Despite their limitations,
cycles have often been successful in revealing otherwise unknown information.
Most of the elements for which no cycles exist are radioactively unstable
or are used rarely and in small amounts. For a variety of reasons,
the anthropogenic cycles of only perhaps a dozen elements are well
characterized. For all the others, with cycles limited or nonexistent,
our knowledge of types of uses, lifetimes in those uses, international
trade, losses to the environment, and rates of recycling is quite
limited, thereby making attempts to evaluate resource sustainability
particularly problematic
Inter-Sectoral Bisphenol A (BPA) Flows in the 2012 Chinese Economy
Bisphenol
A (BPA), a widely used petrochemical compound, has become
an emerging global environmental management challenge because its
leakage is associated with potential environmental and human health
impacts. Until now, available BPA statistics have been limited to
the products that directly use BPA. In this study, we delineate direct
and indirect BPA flows for the 2012 Chinese economy. We find that
construction, production of educational and recreational products,
and automobile manufacturing are the most BPA-intensive sectors in
terms of total BPA flows (300, 157, and 130 Gg total BPA flows, respectively).
The public management and health sectors, however, incur significant
indirect BPA flows, defined as embedded and inter-sectoral BPA placed
into use, even though direct BPA use by these sectors is limited.
By revealing the currently overlooked indirect BPA flows, this study
reveals data gaps that are highly relevant to improving the accuracy
of estimated BPA flows and losses. The method used herein is transferrable
to other emerging and environmentally relevant materials, thereby
providing the holistic understanding needed for cities, regions, or
nations to design effective policy interventions
Dynamic Stocks and Flows Analysis of Bisphenol A (BPA) in China: 2000ā2014
Bisphenol
A (BPA), a synthetic organic chemical, is creating a
new category of ecological and human health challenges due to unintended
leakage. Effectively managing the use and leakage of BPA can benefit
from an understanding of the anthropogenic BPA cycles (i.e., the size
of BPA flows and stocks). In this work, we provide a dynamic analysis
of the anthropogenic BPA cycles in China for 2000ā2014. We
find that Chinaās BPA consumption has increased 10-fold since
2000, to ā¼3 million tonnes/year. With the increasing consumption,
Chinaās in-use BPA stock has increased 500-fold to 14.0 million
tonnes (i.e., 10.2 kg BPA/capita). It is unclear whether a saturation
point has been reached, but in 2004ā2014, Chinaās in-use
BPA stock has been increasing by 0.8 kg BPA/capita annually. Electronic
products are the biggest contributor, responsible for roughly one-third
of Chinaās in-use BPA stock. Optical media (DVD/VCD/CDs) is
the largest contributor to Chinaās current End-of-Life (EoL)
BPA flow, totaling 0.9 million tonnes/year. However, the EoL BPA flow
due to e-waste will increase quickly, and will soon become the largest
EoL BPA flow. The changing quantities and sources of EoL BPA flows
may require a shift in the macroscopic BPA management strategies
Building the Material Flow Networks of Aluminum in the 2007 U.S. Economy
Based
on the combination of the U.S. economic input-output table
and the stocks and flows framework for characterizing anthropogenic
metal cycles, this study presents a methodology for building material
flow networks of bulk metals in the U.S. economy and applies it to
aluminum. The results, which we term the InputāOutput Material
Flow Networks (IO-MFNs), achieve a complete picture of aluminum flow
in the entire U.S. economy and for any chosen industrial sector (illustrated
for the Automobile Manufacturing sector). The results are compared
with information from our former study on U.S. aluminum stocks and
flows to demonstrate the robustness and value of this new methodology.
We find that the IO-MFN approach has the following advantages: (1)
it helps to uncover the network of material flows in the manufacturing
stage in the life cycle of metals; (2) it provides a method that may
be less time-consuming but more complete and accurate in estimating
new scrap generation, process loss, domestic final demand, and trade
of final products of metals, than existing material flow analysis
approaches; and, most importantly, (3) it enables the analysis of
the material flows of metals in the U.S. economy from a network perspective,
rather than merely that of a life cycle chain
Building the Material Flow Networks of Aluminum in the 2007 U.S. Economy
Based
on the combination of the U.S. economic input-output table
and the stocks and flows framework for characterizing anthropogenic
metal cycles, this study presents a methodology for building material
flow networks of bulk metals in the U.S. economy and applies it to
aluminum. The results, which we term the InputāOutput Material
Flow Networks (IO-MFNs), achieve a complete picture of aluminum flow
in the entire U.S. economy and for any chosen industrial sector (illustrated
for the Automobile Manufacturing sector). The results are compared
with information from our former study on U.S. aluminum stocks and
flows to demonstrate the robustness and value of this new methodology.
We find that the IO-MFN approach has the following advantages: (1)
it helps to uncover the network of material flows in the manufacturing
stage in the life cycle of metals; (2) it provides a method that may
be less time-consuming but more complete and accurate in estimating
new scrap generation, process loss, domestic final demand, and trade
of final products of metals, than existing material flow analysis
approaches; and, most importantly, (3) it enables the analysis of
the material flows of metals in the U.S. economy from a network perspective,
rather than merely that of a life cycle chain
Anthropogenic Cycles of Arsenic in Mainland China: 1990ā2010
Arsenic (As) is a trace element in
the global environment with
toxicity to both humans and ecosystem. This study characterizes Chinaās
historical anthropogenic arsenic cycles (AACs) from 1990 to 2010.
Key findings include the following: (1) the scale of Chinaās
AACs grew significantly during the studied period, making China the
biggest miner, producer, and user of arsenic today; (2) the majority
of arsenic flows into Chinaās anthroposphere are the impurity
of domestically mined nonferrous metal ores, which far exceeds domestic
intentional demands; (3) China has been a net exporter of arsenic
trioxide and arsenic metalloid, thus suffering from the environmental
burdens of producing arsenic products for other economies; (4) the
growth of arsenic use in China is driven by simultaneous increases
in many applications including glass making, wood preservatives, batteries,
semiconductors, and alloys, implying the challenge for regulating
arsenic uses in multiple applications/industries at the same time;
(5) the dissipative arsenic emissions resulting from intentional applications
are at the same order of magnitude as atmospheric emissions from coal
combustion, and their threats to human and ecosystem health can spread
widely and last years to decades. Our results demonstrate that the
characterization of AACs is indispensable for developing a complete
arsenic emission inventory
Identified nitrotyrosine or aminotyrosine modifications in Avastin by HCT and Orbitrap: the software proposes possible modifications on the peptide and subsequently assigns them to āmeasured m/zā. The theoretical m/z indicates the peptide mass with expected modifications.
a<p>Avastin Heavy chain</p>b<p>Avastin Light chain</p>c<p>Both nitrotyrosine and aminotyrosine modifications are identified at the same Y192 site of Spot 6.</p>d<p>given in Da</p
2-DE image of AvastinĀ® is shown providing assignments of identified protein spots.
<p>2-DE image of AvastinĀ® is shown providing assignments of identified protein spots.</p
The modifications verified by HCT and Orbitrap.
<p>The modifications verified by HCT and Orbitrap.</p