92 research outputs found
RADIOACTIVE DEMONSTRATION OF FINAL MINERALIZED WASTE FORMS FOR HANFORD WASTE TREATMENT PLANT SECONDARY WASTE BY FLUIDIZED BED STEAM REFORMING USING THE BENCH SCALE REFORMER PLATFORM
The U.S. Department of Energy's Office of River Protection (ORP) is responsible for the retrieval, treatment, immobilization, and disposal of Hanford's tank waste. Currently there are approximately 56 million gallons of highly radioactive mixed wastes awaiting treatment. A key aspect of the River Protection Project (RPP) cleanup mission is to construct and operate the Waste Treatment and Immobilization Plant (WTP). The WTP will separate the tank waste into high-level and low-activity waste (LAW) fractions, both of which will subsequently be vitrified. The projected throughput capacity of the WTP LAW Vitrification Facility is insufficient to complete the RPP mission in the time frame required by the Hanford Federal Facility Agreement and Consent Order, also known as the Tri-Party Agreement (TPA), i.e. December 31, 2047. Therefore, Supplemental Treatment is required both to meet the TPA treatment requirements as well as to more cost effectively complete the tank waste treatment mission. In addition, the WTP LAW vitrification facility off-gas condensate known as WTP Secondary Waste (WTP-SW) will be generated and enriched in volatile components such as {sup 137}Cs, {sup 129}I, {sup 99}Tc, Cl, F, and SO{sub 4} that volatilize at the vitrification temperature of 1150 C in the absence of a continuous cold cap (that could minimize volatilization). The current waste disposal path for the WTP-SW is to process it through the Effluent Treatment Facility (ETF). Fluidized Bed Steam Reforming (FBSR) is being considered for immobilization of the ETF concentrate that would be generated by processing the WTP-SW. The focus of this current report is the WTP-SW. FBSR offers a moderate temperature (700-750 C) continuous method by which WTP-SW wastes can be processed irrespective of whether they contain organics, nitrates, sulfates/sulfides, chlorides, fluorides, volatile radionuclides or other aqueous components. The FBSR technology can process these wastes into a crystalline ceramic (mineral) waste form. The mineral waste form that is produced by co-processing waste with kaolin clay in an FBSR process has been shown to be as durable as LAW glass. Monolithing of the granular FBSR product is being investigated to prevent dispersion during transport or burial/storage, but is not necessary for performance. A Benchscale Steam Reformer (BSR) was designed and constructed at the SRNL to treat actual radioactive wastes to confirm the findings of the non-radioactive FBSR pilot scale tests and to qualify the waste form for applications at Hanford. BSR testing with WTP SW waste surrogates and associated analytical analyses and tests of granular products (GP) and monoliths began in the Fall of 2009, and then was continued from the Fall of 2010 through the Spring of 2011. Radioactive testing commenced in 2010 with a demonstration of Hanford's WTP-SW where Savannah River Site (SRS) High Level Waste (HLW) secondary waste from the Defense Waste Processing Facility (DWPF) was shimmed with a mixture of {sup 125/129}I and {sup 99}Tc to chemically resemble WTP-SW. Prior to these radioactive feed tests, non-radioactive simulants were also processed. Ninety six grams of radioactive granular product were made for testing and comparison to the non-radioactive pilot scale tests. The same mineral phases were found in the radioactive and non-radioactive testing
Radioactive Demonstration Of Mineralized Waste Forms Made From Hanford Low Activity Waste (Tank SX-105, Tank AN-103, And AZ-101/102) By Fluidized Bed Steam Reformation (FBSR)
Fluidized Bed Steam Reforming (FBSR) is a robust technology for the immobilization of a wide variety of radioactive wastes. Applications have been tested at the pilot scale for the high sodium, sulfate, halide, organic and nitrate wastes at the Hanford site, the Idaho National Laboratory (INL), and the Savannah River Site (SRS). Due to the moderate processing temperatures, halides, sulfates, and technetium are retained in mineral phases of the feldspathoid family (nepheline, sodalite, nosean, carnegieite, etc). The feldspathoid minerals bind the contaminants such as Tc-99 in cage (sodalite, nosean) or ring (nepheline) structures to surrounding aluminosilicate tetrahedra in the feldspathoid structures. The granular FBSR mineral waste form that is produced has a comparable durability to LAW glass based on the short term PCT testing in this study, the INL studies, SPFT and PUF testing from previous studies as given in the columns in Table 1-3 that represent the various durability tests. Monolithing of the granular product was shown to be feasible in a separate study. Macro-encapsulating the granular product provides a decrease in leaching compared to the FBSR granular product when the geopolymer is correctly formulated
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2009 Pilot Scale Fluidized Bed Steam Reforming Testing Using the Thor (Thermal Organic Reduction) Process: Analytical Results for Tank 48h Organic Destruction - 10408
The Savannah River Site (SRS) must empty the contents of Tank 48H, a 1.3 million gallon Type IIIA HLW storage tank, to return this tank to service. The tank contains organic compounds, mainly potassium tetraphenylborate that cannot be processed downstream until the organic components are destroyed. The THOR{reg_sign} Treatment Technologies (TTT) Fluidized Bed Steam Reforming (FBSR) technology, herein after referred to as steam reforming, has been demonstrated to be a viable process to remove greater than 99.9% of the organics from Tank 48H during various bench scale and pilot scale tests. These demonstrations were supported by Savannah River Remediation (SRR) and the Department of Energy (DOE) has concurred with the SRR recommendation to proceed with the deployment of the FBSR technology to treat the contents of Tank 48H. The Savannah River National Laboratory (SRNL) developed and proved the concept with non-radioactive simulants for SRR beginning in 2003. By 2008, several pilot scale campaigns had been completed and extensive crucible testing and bench scale testing were performed in the SRNL Shielded Cells using Tank 48H radioactive sample. SRNL developed a Tank 48H non-radioactive simulant complete with organic compounds, salt, and metals characteristic of those measured in a sample of the radioactive contents of Tank 48H. FBSR Pilot Scaled Testing with the Tank 48H simulant has demonstrated the ability to remove greater than 98% of the nitrites and greater than 99.5% of the nitrates from the Tank 48H simulant, and to form a solid product that is primarily alkali carbonate. The alkali carbonate is soluble and, thus, amenable to pumping as a liquid to downstream facilities for processing. The FBSR technology was demonstrated in October of 2006 in the Engineering Scale Test Demonstration (ESTD) pilot scale steam reformer at the Hazen Research Inc. (HRI) facility in Golden, CO. Additional ESTD tests were completed in 2008 and in 2009 that further demonstrated the TTT steam reforming process ability to destroy organics in the Tank 48 simulant and produce a soluble carbonate waste form. The ESTD was operated at varying feed rates and Denitration and Mineralization Reformer (DMR) temperatures, and at a constant Carbon Reduction Reformer (CRR) temperature of 950 C. The process produced a dissolvable carbonate product suitable for processing downstream. ESTD testing was performed in 2009 at the Hazen facility to demonstrate the long term operability of an integrated FBSR processing system with carbonate product and carbonate slurry handling capability. The final testing demonstrated the integrated TTT FBSR capability to process the Tank 48 simulant from a slurry feed into a greater than 99.9% organic free and primarily dissolved carbonate FBSR product slurry. This paper will discuss the SRNL analytical results of samples analyzed from the 2008 and 2009 THOR{reg_sign} steam reforming ESTD performed with Tank 48H simulant at HRI in Golden, Colorado. The final analytical results will be compared to prior analytical results from samples in terms of organic, nitrite, and nitrate destruction
The Broad-lined Type Ic SN 2003jd
The results of a world-wide coordinated observational campaign on the
broad-lined Type Ic SN 2003jd are presented. In total, 74 photometric data
points and 26 spectra were collected using 11 different telescopes. SN 2003jd
is one of the most luminous SN Ic ever observed. A comparison with other Type
Ic supernovae (SNe Ic) confirms that SN 2003jd represents an intermediate case
between broad-line events (2002ap, 2006aj), and highly energetic SNe (1997ef,
1998bw, 2003dh, 2003lw), with an ejected mass of M_{ej} = 3.0 +/- 1 Mo and a
kinetic energy of E_{k}(tot) = 7_{-2}^{+3} 10^{51} erg. SN 2003jd is similar to
SN 1998bw in terms of overall luminosity, but it is closer to SNe 2006aj and
2002ap in terms of light-curve shape and spectral evolution. The comparison
with other SNe Ic, suggests that the V-band light curves of SNe Ic can be
partially homogenized by introducing a time stretch factor. Finally, due to the
similarity of SN 2003jd to the SN 2006aj/XRF 060218 event, we discuss the
possible connection of SN 2003jd with a GRB.Comment: 19 pages, 19 figures, Accepted for publication in MNRA
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Radioactive Demonstration Of Mineralized Waste Forms Made From Hanford Low Activity Waste (Tank Farm Blend) By Fluidized Bed Steam Reformation (FBSR)
The U.S. Department of Energy’s Office of River Protection (ORP) is responsible for the retrieval, treatment, immobilization, and disposal of Hanford’s tank waste. A key aspect of the River Protection Project (RPP) cleanup mission is to construct and operate the Hanford Tank Waste Treatment and Immobilization Plant (WTP). The WTP will separate the tank waste into high-level and low-activity waste (LAW) fractions, both of which will subsequently be vitrified. The projected throughput capacity of the WTP LAW Vitrification Facility is insufficient to complete the RPP mission in the time frame required by the Hanford Federal Facility Agreement and Consent Order, also known as the Tri-Party Agreement (TPA), i.e. December 31, 2047. Supplemental Treatment is likely to be required both to meet the TPA treatment requirements as well as to more cost effectively complete the tank waste treatment mission. The Supplemental Treatment chosen will immobilize that portion of the retrieved LAW that is not sent to the WTP’s LAW Vitrification facility into a solidified waste form. The solidified waste will then be disposed on the Hanford site in the Integrated Disposal Facility (IDF). Fluidized Bed Steam Reforming (FBSR) offers a moderate temperature (700-750°C) continuous method by which LAW can be processed irrespective of whether the waste contain organics, nitrates, sulfates/sulfides, chlorides, fluorides, volatile radionuclides or other aqueous components. The FBSR technology can process these wastes into a crystalline ceramic (mineral) waste form. The mineral waste form that is produced by co-processing waste with kaolin clay in an FBSR process has been shown to be comparable to LAW glass, i.e. leaches Tc-99, Re and Na at 6 (the Hanford IDF criteria for Na) in the first few hours. The granular and monolithic waste forms also pass the EPA Toxicity Characteristic Leaching Procedure (TCLP) for all Resource Conservation and Recovery Act (RCRA) components at the Universal Treatment Standards (UTS). Two identical Benchscale Steam Reformers (BSR) were designed and constructed at SRNL, one to treat non-radioactive simulants and the other to treat actual radioactive wastes. The results from the non-radioactive BSR were used to determine the parameters needed to operate the radioactive BSR in order to confirm the findings of non-radioactive FBSR pilot scale and engineering scale tests and to qualify an FBSR LAW waste form for applications at Hanford. Radioactive testing commenced using SRS LAW from Tank 50 chemically trimmed to look like Hanford’s blended LAW known as the Rassat simulant as this simulant composition had been tested in the non-radioactive BSR, the non-radioactive pilot scale FBSR at the Science Applications International Corporation-Science and Technology Applications Research (SAIC-STAR) facility in Idaho Falls, ID and in the TTT Engineering Scale Technology Demonstration (ESTD) at Hazen Research Inc. (HRI) in Denver, CO. This provided a “tie back” between radioactive BSR testing and non-radioactive BSR, pilot scale, and engineering scale testing. Approximately six hundred grams of non-radioactive and radioactive BSR product were made for extensive testing and comparison to the non-radioactive pilot scale tests performed in 2004 at SAIC-STAR and the engineering scale test performed in 2008 at HRI with the Rassat simulant. The same mineral phases and off-gas species were found in the radioactive and non-radioactive testing. The granular ESTD and BSR products (radioactive and non-radioactive) were analyzed for total constituents and durability tested as a granular waste form. A subset of the granular material was stabilized in a clay based geopolymer matrix at 42% and 65% FBSR loadings and durability tested as a monolith waste form. The 65 wt% FBSR loaded monolith made with clay (radioactive) was more durable than the 67-68 wt% FBSR loaded monoliths made from fly ash (non-radioactive) based on short term PCT testing. Long term, 90 to 107 day, ASTM C1308 testing (similar to ANSI/ANS 16.1 testing) was only performed on two fly ash geopolymer monoliths at 67-68 wt% FBSR loading and three clay geopolymer monoliths at 42 wt% FBSR loading. More clay geopolymers need to be made and tested at longer times at higher FBSR loadings for comparison to the fly ash monoliths. Monoliths made with metakaolin (heat treated) clay are of a more constant composition and are very reactive as the heat treated clay is amorphous and alkali activated. The monoliths made with fly ash are subject to the inherent compositional variation found in fly ash as it is a waste product from burning coal and it contains unreactive components such as mullite. However, both the fly ash and the clay based monoliths perform well in long term ASTM C1308 testing. Extensive testing and characterization of the granular and monolith material were made including the following American Society of Testing and Materials (ASTM) tests: ASTM C1285 testing (Product Consistency Test) of granular and monolithic waste forms; Comparison of granular BSR radioactive to ESTD and pilot scale granular non-radioactive waste form made from the Rassat simulant Comparison of granular radioactive to granular non-radioactive waste form made from the Rassat simulant made using the SRNL BSR; Comparison of monolithic BSR radioactive waste forms to monolithic BSR and ESTD non-radioactive waste forms made of fly ash; Comparison of granular BSR radioactive waste forms to monolithic BSR non-radioactive waste forms made of fly ash; Comparison of granular BSR radioactive waste forms to monolithic BSR non-radioactive waste forms made of clay; ASTM C1308 Accelerated Leach Test for Diffusive Releases from Solidified Waste and a Computer Program to Model Diffusive, Fractional Leaching from Cylindrical Waste Forms; Comparison of BSR non-radioactive waste forms to monolithic ESTD non-radioactive waste forms made from fly ash; Testing of BSR non-radioactive monoliths made from clay for comparison to non-radioactive monoliths made from fly ash; ASTM C39 Compressive Strength of Cylindrical Concrete Specimens; Comparison of monolithic BSR radioactive waste forms to monolithic BSR and ESTD non-radioactive waste forms; EPA Manual SW-846 Method 1311, Toxicity Characteristic Leaching Procedure (TCLP); Comparison of granular BSR radioactive to ESTD and pilot scale granular non-radioactive waste form made from the Rassat simulant; Comparison of granular radioactive to granular non-radioactive waste form made from the Rassat simulant made using the SRNL BSR; Comparison of monolithic BSR radioactive waste forms to monolithic BSR non-radioactive waste forms
Neurobiology of rodent self-grooming and its value for translational neuroscience
Self-grooming is a complex innate behaviour with an evolutionarily conserved sequencing pattern and is one of the most frequently performed behavioural activities in rodents. In this Review, we discuss the neurobiology of rodent self-grooming, and we highlight studies of rodent models of neuropsychiatric disorders-including models of autism spectrum disorder and obsessive compulsive disorder-that have assessed self-grooming phenotypes. We suggest that rodent self-grooming may be a useful measure of repetitive behaviour in such models, and therefore of value to translational psychiatry. Assessment of rodent self-grooming may also be useful for understanding the neural circuits that are involved in complex sequential patterns of action.National Institutes of Health (U.S.) (Grant NS025529)National Institutes of Health (U.S.) (Grant HD028341)National Institutes of Health (U.S.) (Grant MH060379
Oxidative Dehydrogenation of Ethylbenzene Over Poly(furfuryl alcohol)-Derived CMK-1 Carbon Replica
Estimating the burden of selected non-communicable diseases in Africa: a systematic review of the evidence
Background
The burden of non-communicable diseases (NCDs) is rapidly increasing globally, and
particularly in Africa, where the health focus, until recently, has been on infectious diseases. The
response to this growing burden of NCDs in Africa has been affected owing to a poor
understanding of the burden of NCDs, and the relative lack of data and low level of research on
NCDs in the continent. Recent estimates on the burden of NCDs in Africa have been mostly
derived from modelling based on data from other countries imputed into African countries, and
not usually based on data originating from Africa itself. In instances where few data were
available, estimates have been characterized by extrapolation and over-modelling of the scarce
data. It is therefore believed that underestimation of NCDs burden in many parts of Africa cannot
be unexpected. With a gradual increase in average life expectancy across Africa, the region now
experiencing the fastest rate of urbanization globally, and an increase adoption of unhealthy
lifestyles, the burden of NCDs is expected to rise. This thesis will, therefore, be focussing on
understanding the prevalence, and/or where there are available data, the incidence, of four major
NCDs in Africa, which have contributed highly to the burden of NCDs, not only in Africa, but
also globally.
Methods
I conducted a systematic search of the literature on three main databases (Medline, EMBASE and
Global Health) for epidemiological studies on NCDs conducted in Africa. I retained and
extracted data from original population-based (cohort or cross sectional), and/or health service
records (hospital or registry-based studies) on prevalence and/or incidence rates of four major
NCDs in Africa. These include: cardiovascular diseases (hypertension and stroke), diabetes,
major cancer types (cervical, breast, prostate, ovary, oesophagus, bladder, Kaposi, liver, stomach,
colorectal, lung and non-Hodgkin lymphoma), and chronic respiratory diseases (chronic
obstructive pulmonary disease (COPD) and asthma). From extracted crude prevalence and
incidence rates, a random effect meta-analysis was conducted and reported for each NCD. An
epidemiological model was applied on all extracted data points. The fitted curve explaining the
largest proportion of variance (best fit) from the model was further applied. The equation
generated from the fitted curve was used to determine the prevalence and cases of the specific
NCD in Africa at midpoints of the United Nations (UN) population 5-year age-group population
estimates for Africa.
Results
From the literature search, studies on hypertension had the highest publication output at 7680, 92
of which were selected, spreading across 31 African countries. Cancer had 9762 publications and
39 were selected across 20 countries; diabetes had 3701 publications and 48 were selected across
28 countries; stroke had 1227 publications and 19 were selected across 10 countries; asthma had
790 publications and 45 were selected across 24 countries; and COPD had the lowest output with
243 publications and 13 were selected across 8 countries. From studies reporting prevalence
rates, hypertension, with a total sample size of 197734, accounted for 130.2 million cases and a
prevalence of 25.9% (23.5, 34.0) in Africa in 2010. This is followed by asthma, with a sample
size of 187904, accounting for 58.2 million cases and a prevalence of 6.6% (2.4, 7.9); COPD,
with a sample size of 24747, accounting for 26.3 million cases and a prevalence of 13.4% (9.4,
22.1); diabetes, with a sample size of 102517, accounting for 24.5 million cases and a prevalence
of 4.0% (2.7, 6.4); and stroke, with a sample size of about 6.3 million, accounting for 1.94
million cases and a prevalence of 317.3 per 100000 population (314.0, 748.2). From studies
reporting incidence rates, stroke accounted for 496 thousand new cases in Africa in 2010, with a
prevalence of 81.3 per 100000 person years (13.2, 94.9). For the 12 cancer types reviewed, a total
of 775 thousand new cases were estimated in Africa in 2010 from registry-based data covering a
total population of about 33 million. Among women, cervical cancer and breast cancer had 129
thousand and 81 thousand new cases, with incidence rates of 28.2 (22.1, 34.3) and 17.7 (13.0,
22.4) per 100000 person years, respectively. Among men, prostate cancer and Kaposi sarcoma
closely follows with 75 thousand and 74 thousand new cases, with incidence rates of 14.5 (10.9,
18.0) and 14.3 (11.9, 16.7) per 100000 person years, respectively.
Conclusion
This study suggests the prevalence rates of the four major NCDs reviewed (cardiovascular
diseases (hypertension and stroke), diabetes, major cancer types, and chronic respiratory diseases
(COPD and asthma) in Africa are high relative to global estimates. Due to the lack of data on
many NCDs across the continent, there are still doubts on the true prevalence of these diseases
relative to the current African population. There is need for improvement in health information
system and overall data management, especially at country level in Africa. Governments of
African nations, international organizations, experts and other stakeholders need to invest more
on NCDs research, particularly mortality, risk factors, and health determinants to have
evidenced-based facts on the drivers of this epidemic in the continent, and prompt better,
effective and overall public health response to NCDs in Africa
Neuronal mechanisms and circuits underlying repetitive behaviors in mouse models of autism spectrum disorder
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Fluidized Bed Steam Reforming (FBSR) of High Level Waste (HLW) Organic and Nitrate Destruction Prior to Vitrification: Crucible Scale to Engineering Scale Demonstrations and Non-Radioactive to Radioactive Demonstrations
Over a decade ago, an in-tank precipitation process to remove Cs-137 from radioactive high level waste (HLW) supernates was demonstrated at the Savannah River Site (SRS). The full scale demonstration with actual HLW was performed in SRS Tank 48 (T48). Sodium tetraphenylborate (NaTPB) was added to enable Cs-137 extraction as CsTPB. The CsTPB, an organic, and its decomposition products proved to be problematic for subsequent processing of the Cs-137 precipitate in the SRS HLW vitrification facility for ultimate disposal in a HLW repository. Fluidized Bed Steam Reforming (FBSR) is being considered as a technology for destroying the organics and nitrates in the T48 waste to render it compatible with subsequent HLW vitrification. During FBSR processing the T48 waste is converted into organic-free and nitrate-free carbonate-based minerals which are water soluble. The soluble nature of the carbonate-based minerals allows them to be dissolved and pumped to the vitrification facility or returned to the tank farm for future vitrification. The initial use of the FBSR process for T48 waste was demonstrated with simulated waste in 2003 at the Savannah River National Laboratory (SRNL) using a specially designed sealed crucible test that reproduces the FBSR pyrolysis reactions, i.e. carbonate formation, organic and nitrate destruction. This was followed by pilot scale testing of simulants at the Science Applications International Corporation (SAIC) Science & Technology Application Research (STAR) Center in Idaho Falls, ID by Idaho National Laboratory (INL) and SRNL in 2003-4 and then engineering scale demonstrations by THOR{reg_sign} Treatment Technologies (TTT) and SRS/SRNL at the Hazen Research, Inc. (HRI) test facility in Golden, CO in 2006 and 2008. Radioactive sealed crucible testing with real T48 waste was performed at SRNL in 2008, and radioactive Benchscale Steam Reformer (BSR) testing was performed in the SRNL Shielded Cell Facility (SCF) in 2008
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