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Zooplankton from OTEC sites in the Gulf of Mexico and the Caribbean

Description: The spatial and temporal variations in the abundance of major classes of zooplankton were measured using standard methods, between June and October 1978, at two OTEC sites in the Gulf of Mexico and in the Caribbean near Puerto Rico. The usual oceanic patterns were found with highest numbers near the surface, especially at night, and lowest numbers at 800 to 1000 m. Absolute numbers varied considerably from site to site. As expected, copepods (usually divided between calanoids and cyclopoids) dominated the zooplankton at all sites.
Date: June 1, 1979
Creator: Commins, M.L. & Horne, A.J.
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ZORCH--AN IBM 7090 PROGRAM FOR THE ANALYSIS OF SIMULATED MSRE POWER TRANSIENTS WITH A SIMPLIFIED SPACE-DEPENDENT KINETICS MODEL

Description: A program (ZORCH) is described which is an extended and revised version of the point-model kinetics program MURGATROYD. A model is used in which the axial space dependence of the fuel and graphite temperatures is calculated, and the effect on reactivity of deviations from the steady state values is assumed to be given by the product of an appropriate temperature coefficient of reactivity times the deviations from the steady state value of the nuclear average temperature (NAT). The NAT is computed using a sine-squared'' weighting function in the axial direction and using an input weighting factor in the radial direction. The shape of the power density is taken to be - time- independent in contrast to the shapes of the temperature distributions, which are time-dependent in the calculation. This program is intended to be used in surveys of reactor behavior under a wide range of conditions. It is therefore based on a simplified model in order to reduce computing time, but should provide a better approximation to reactor behavior than does a purely space-independent calculation. A derivation of the equations used in the program, instructions for its use, and sample input and output for a test case are included. A FORTRAN source deck and a binary object deck are on file. (auth)
Date: September 18, 1962
Creator: Nestor, C. W. Jr.
open access

ZORNOC: a 1 1/2-D tokamak data analysis code for studying noncircular high beta plasmas

Description: A new tokamak data analysis code, ZORNOC, was developed to study noncircular, high beta plasmas in the Impurity Study Experiment (ISX-B). These plasmas exhibit significant flux surface shifts and elongation in both ohmically heated and beam-heated discharges. The MHD equilibrium flux surface geometry is determined by solving the Grad-Shafranov equation based on: (1) the shape of the outermost flux surface, deduced from the magnetic loop probes; (2) a pressure profile, deduced by means of Thomson scattering data (electrons), charge exchange data (ions), and a Fokker-Planck model (fast ions); and (3) a safety factor profile, determined from the experimental data using a simple model (Z/sub eff/ = const) that is self-consistently altered while the plasma equilibrium is iterated. For beam-heated discharches the beam deposition profile is determined by means of a Monte Carlo scheme and the slowing down of the fast ions by means of an analytical solution of the Fokker-Planck equation. The code also carries out an electron power balance and calculates various confinement parameters. The code is described and examples of its operation are given.
Date: March 1, 1980
Creator: Zurro, B.; Wieland, R. M.; Murakami, M. & Swain, D. W.
open access

ZPPR-20 Phase D : A Cylindrical Assembly of Polyethylene Moderated U Metal Reflected by Beryllium Oxide and Polyethylene.

Description: The Zero Power Physics Reactor (ZPPR) fast critical facility was built at the Argonne National Laboratory-West (ANL-W) site in Idaho in 1969 to obtain neutron physics information necessary for the design of fast breeder reactors. The ZPPR-20D Benchmark Assembly was part of a series of cores built in Assembly 20 (References 1 through 3) of the ZPPR facility to provide data for developing a nuclear power source for space applications (SP-100). The assemblies were beryllium oxide reflected and had core fuel compositions containing enriched uranium fuel, niobium and rhenium. ZPPR-20 Phase C (HEU-MET-FAST-075) was built as the reference flight configuration. Two other configurations, Phases D and E, simulated accident scenarios. Phase D modeled the water immersion scenario during a launch accident, and Phase E (SUB-HEU-MET-FAST-001) modeled the earth burial scenario during a launch accident. Two configurations were recorded for the simulated water immersion accident scenario (Phase D); the critical configuration, documented here, and the subcritical configuration (SUB-HEU-MET-MIXED-001). Experiments in Assembly 20 Phases 20A through 20F were performed in 1988. The reference water immersion configuration for the ZPPR-20D assembly was obtained as reactor loading 129 on October 7, 1988 with a fissile mass of 167.477 kg and a reactivity of -4.626 {+-} 0.044{cents} (k {approx} 0.9997). The SP-100 core was to be constructed of highly enriched uranium nitride, niobium, rhenium and depleted lithium. The core design called for two enrichment zones with niobium-1% zirconium alloy fuel cladding and core structure. Rhenium was to be used as a fuel pin liner to provide shut down in the event of water immersion and flooding. The core coolant was to be depleted lithium metal ({sup 7}Li). The core was to be surrounded radially with a niobium reactor vessel and bypass which would carry the lithium coolant to the forward inlet plenum. Immediately inside the …
Date: September 30, 2006
Creator: Lell, R.; Grimm, K.; McKnight, R.; Shaefer, R.; Division, Nuclear Engineering & INL
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ZPPR progress report: August 1987-October 1987

Description: This progress report details activities during the time period of August through October, 1987. Results are presented from the axially heterogeneous assembly ZPPR-17, a part of the Jupiter-III program. The loading of the ZPPR-17B assembly, with 25 control rod positions, is described along with operational measurements, calculation models, measurements and predictions of criticality and measured axial worth profiles for B[sub 4]C. From ZPPR-17A, calculated and measured results are given for banks of control rod positions along with revised measured values for various single, central control rods.
Date: November 16, 1987
Creator: Brumbach, S.B. & Collins, P.J.
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ZPPR progress report: February 1988 through April 1988

Description: Results are presented for control rod worth experiments in the axially heterogeneous assembly ZPPR-17, a part of the JUPITER-III program. From the earlier metal-fuel ZPPR-15 program, results are given for measurements and calculations of neutron spectra and sodium voiding in several configurations.
Date: May 13, 1988
Creator: Brumbach, S.B. & Collins, P.J.
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ZPPR progress report, January 1989 through April 1989

Description: Further results are presented from the large, homogeneous assembly ZPPR-18 in the JUPITER-III program. Reaction rate results are given for ZPPR-18B along with measured gamma ray dose results from ZPPR-18A and 18B. Control rod worth results from the ZPPR-18 assemblies are included. Calculation models, measured and calculated k-effective values and measured sodium worth values, are presented for the ZPPR-19 assemblies of the lo program.
Date: April 27, 1989
Creator: Collins, P.J. & Brumbach, S.B.
open access

ZPPR progress report: November 1987-January 1988

Description: This report details activities for the time period of November, 1987 through January, 1988. Further results are presented from the axially heterogeneous assembly ZPPR-17, a part of the JUPITER-III program. The loading of the ZPPR-17C assembly, with 13 half-inserted control rods, is described along with operational measurements, calculation models, and measurements and prediction of criticality. From ZPPR-17A, calculated and measured results are given for reaction rates and measured results for bowing, expansion and small sample worth experiments. From the earlier metal-fuel ZPPR-15 program results are given for measurements and calculations of Doppler reactivity coefficients.
Date: February 15, 1988
Creator: Collins, P.J. & Brumbach, S.B.
open access

ZPPR progress report: September 1988--December 1988

Description: Further results are presented from the JUPITER-III program. Calculation models and k-effective results are given for the three configurations of the large, homogeneous assembly ZPPR-18. Reaction rate results, including sodium activation are given for ZPPR-18A. Also included are spatial decoupling results from ZPPR-18. As a successor to JUPITER-III, the Io program investigated the effects of uranium fuel distribution in mixed uranium and plutonium fueled assemblies. The ZPPR-19A and 19B assemblies which made up the Io program are described.
Date: January 20, 1989
Creator: Brumbach, S.B. & Collins, P.J.
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ZPR-3 Assembly 11 : A cylindrical sssembly of highly enriched uranium and depleted uranium with an average {sup 235}U enrichment of 12 atom % and a depleted uranium reflector.

Description: Over a period of 30 years, more than a hundred Zero Power Reactor (ZPR) critical assemblies were constructed at Argonne National Laboratory. The ZPR facilities, ZPR-3, ZPR-6, ZPR-9 and ZPPR, were all fast critical assembly facilities. The ZPR critical assemblies were constructed to support fast reactor development, but data from some of these assemblies are also well suited for nuclear data validation and to form the basis for criticality safety benchmarks. A number of the Argonne ZPR/ZPPR critical assemblies have been evaluated as ICSBEP and IRPhEP benchmarks. Of the three classes of ZPR assemblies, engineering mockups, engineering benchmarks and physics benchmarks, the last group tends to be most useful for criticality safety. Because physics benchmarks were designed to test fast reactor physics data and methods, they were as simple as possible in geometry and composition. The principal fissile species was {sup 235}U or {sup 239}Pu. Fuel enrichments ranged from 9% to 95%. Often there were only one or two main core diluent materials, such as aluminum, graphite, iron, sodium or stainless steel. The cores were reflected (and insulated from room return effects) by one or two layers of materials such as depleted uranium, lead or stainless steel. Despite their more complex nature, a small number of assemblies from the other two classes would make useful criticality safety benchmarks because they have features related to criticality safety issues, such as reflection by soil-like material. ZPR-3 Assembly 11 (ZPR-3/11) was designed as a fast reactor physics benchmark experiment with an average core {sup 235}U enrichment of approximately 12 at.% and a depleted uranium reflector. Approximately 79.7% of the total fissions in this assembly occur above 100 keV, approximately 20.3% occur below 100 keV, and essentially none below 0.625 eV - thus the classification as a 'fast' assembly. This assembly is Fast Reactor …
Date: September 30, 2010
Creator: Lell, R. M.; McKnight, R. D.; Tsiboulia, A.; Rozhikhin, Y.; Security, National & Engineering, Inst. of Physics and Power
open access

ZPR-3 Assembly 12 : A Cylindrical Assembly of Highly Enriched Uranium, Depleted Uranium and Graphite With an Average {Sup 235}U Enrichment of 21 Atom %.

Description: Over a period of 30 years, more than a hundred Zero Power Reactor (ZPR) critical assemblies were constructed at Argonne National Laboratory. The ZPR facilities, ZPR-3, ZPR-6, ZPR-9 and ZPPR, were all fast critical assembly facilities. The ZPR critical assemblies were constructed to support fast reactor development, but data from some of these assemblies are also well suited for nuclear data validation and to form the basis for criticality safety benchmarks. A number of the Argonne ZPR/ZPPR critical assemblies have been evaluated as ICSBEP and IRPhEP benchmarks. Of the three classes of ZPR assemblies, engineering mockups, engineering benchmarks and physics benchmarks, the last group tends to be most useful for criticality safety. Because physics benchmarks were designed to test fast reactor physics data and methods, they were as simple as possible in geometry and composition. The principal fissile species was {sup 235}U or {sup 239}Pu. Fuel enrichments ranged from 9% to 95%. Often there were only one or two main core diluent materials, such as aluminum, graphite, iron, sodium or stainless steel. The cores were reflected (and insulated from room return effects) by one or two layers of materials such as depleted uranium, lead or stainless steel. Despite their more complex nature, a small number of assemblies from the other two classes would make useful criticality safety benchmarks because they have features related to criticality safety issues, such as reflection by soil-like material. ZPR-3 Assembly 12 (ZPR-3/12) was designed as a fast reactor physics benchmark experiment with an average core {sup 235}U enrichment of approximately 21 at.%. Approximately 68.9% of the total fissions in this assembly occur above 100 keV, approximately 31.1% occur below 100 keV, and essentially none below 0.625 eV - thus the classification as a 'fast' assembly. This assembly is Fast Reactor Benchmark No. 9 in the …
Date: September 30, 2010
Creator: Lell, R. M.; McKnight, R. D.; Perel, R. L.; Wagschal, J. J.; Division, Nuclear Engineering & Physics, Racah Inst. of
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ZPR-3 Assembly 6f : A Spherical Assembly of Highly Enriched Uranium, Depleted Uranium, Aluminum and Steel With an Average {Sup 235}U Enrichment of 47 Atom %.

Description: Over a period of 30 years, more than a hundred Zero Power Reactor (ZPR) critical assemblies were constructed at Argonne National Laboratory. The ZPR facilities, ZPR-3, ZPR-6, ZPR-9 and ZPPR, were all fast critical assembly facilities. The ZPR critical assemblies were constructed to support fast reactor development, but data from some of these assemblies are also well suited for nuclear data validation and to form the basis for criticality safety benchmarks. A number of the Argonne ZPR/ZPPR critical assemblies have been evaluated as ICSBEP and IRPhEP benchmarks. Of the three classes of ZPR assemblies, engineering mockups, engineering benchmarks and physics benchmarks, the last group tends to be most useful for criticality safety. Because physics benchmarks were designed to test fast reactor physics data and methods, they were as simple as possible in geometry and composition. The principal fissile species was {sup 235}U or {sup 239}Pu. Fuel enrichments ranged from 9% to 95%. Often there were only one or two main core diluent materials, such as aluminum, graphite, iron, sodium or stainless steel. The cores were reflected (and insulated from room return effects) by one or two layers of materials such as depleted uranium, lead or stainless steel. Despite their more complex nature, a small number of assemblies from the other two classes would make useful criticality safety benchmarks because they have features related to criticality safety issues, such as reflection by soil-like material. ZPR-3 Assembly 6 consisted of six phases, A through F. In each phase a critical configuration was constructed to simulate a very simple shape such as a slab, cylinder or sphere that could be analyzed with the limited analytical tools available in the 1950s. In each case the configuration consisted of a core region of metal plates surrounded by a thick depleted uranium metal reflector. The average …
Date: September 30, 2010
Creator: Lell, R. M.; McKnight, R. D; Schaefer, R. W. & Division, Nuclear Engineering
open access

ZPR-6 Assembly 7 High {Sup 240} Pu Core : A Cylindrical Assemby With Mixed (Pu, U)-Oxide Fuel and a Central High {Sup 240} Pu Zone.

Description: Over a period of 30 years more than a hundred Zero Power Reactor (ZPR) critical assemblies were constructed at Argonne National Laboratory. The ZPR facilities, ZPR-3, ZPR-6, ZPR-9 and ZPPR, were all fast critical assembly facilities. The ZPR critical assemblies were constructed to support fast reactor development, but data from some of these assemblies are also well suited to form the basis for criticality safety benchmarks. Of the three classes of ZPR assemblies, engineering mockups, engineering benchmarks and physics benchmarks, the last group tends to be most useful for criticality safety. Because physics benchmarks were designed to test fast reactor physics data and methods, they were as simple as possible in geometry and composition. The principal fissile species was {sup 235}U or {sup 239}Pu. Fuel enrichments ranged from 9% to 95%. Often there were only one or two main core diluent materials, such as aluminum, graphite, iron, sodium or stainless steel. The cores were reflected (and insulated from room return effects) by one or two layers of materials such as depleted uranium, lead or stainless steel. Despite their more complex nature, a small number of assemblies from the other two classes would make useful criticality safety benchmarks because they have features related to criticality safety issues, such as reflection by soil-like material. The term 'benchmark' in a ZPR program connotes a particularly simple loading aimed at gaining basic reactor physics insight, as opposed to studying a reactor design. In fact, the ZPR-6/7 Benchmark Assembly (Reference 1) had a very simple core unit cell assembled from plates of depleted uranium, sodium, iron oxide, U3O8, and plutonium. The ZPR-6/7 core cell-average composition is typical of the interior region of liquid-metal fast breeder reactors (LMFBRs) of the era. It was one part of the Demonstration Reactor Benchmark Program,a which provided integral experiments characterizing …
Date: October 1, 2007
Creator: Lell, R. M.; Schaefer, R. W.; McKnight, R. D.; Tsiboulia, A.; Rozhikhin, Y.; Division, Nuclear Engineering et al.
open access

ZPR-6 Assembly 7 High {Sup 240}Pu Core Experiments : A Fast Reactor Core With Mixed (Pu,U)-Oxide Fuel and a Centeral High{Sup 240}Pu Zone.

Description: ZPR-6 Assembly 7 (ZPR-6/7) encompasses a series of experiments performed at the ZPR-6 facility at Argonne National Laboratory in 1970 and 1971 as part of the Demonstration Reactor Benchmark Program (Reference 1). Assembly 7 simulated a large sodium-cooled LMFBR with mixed oxide fuel, depleted uranium radial and axial blankets, and a core H/D near unity. ZPR-6/7 was designed to test fast reactor physics data and methods, so configurations in the Assembly 7 program were as simple as possible in terms of geometry and composition. ZPR-6/7 had a very uniform core assembled from small plates of depleted uranium, sodium, iron oxide, U{sub 3}O{sub 8} and Pu-U-Mo alloy loaded into stainless steel drawers. The steel drawers were placed in square stainless steel tubes in the two halves of a split table machine. ZPR-6/7 had a simple, symmetric core unit cell whose neutronic characteristics were dominated by plutonium and {sup 238}U. The core was surrounded by thick radial and axial regions of depleted uranium to simulate radial and axial blankets and to isolate the core from the surrounding room. The ZPR-6/7 program encompassed 139 separate core loadings which include the initial approach to critical and all subsequent core loading changes required to perform specific experiments and measurements. In this context a loading refers to a particular configuration of fueled drawers, radial blanket drawers and experimental equipment (if present) in the matrix of steel tubes. Two principal core configurations were established. The uniform core (Loadings 1-84) had a relatively uniform core composition. The high {sup 240}Pu core (Loadings 85-139) was a variant on the uniform core. The plutonium in the Pu-U-Mo fuel plates in the uniform core contains 11% {sup 240}Pu. In the high {sup 240}Pu core, all Pu-U-Mo plates in the inner core region (central 61 matrix locations per half of the split …
Date: February 23, 2009
Creator: Lell, R. M.; Morman, J. A.; Schaefer, R.W. & McKnight, R.D.
open access

ZPR-9 airborne plutonium monitoring system

Description: An airborne plutonium monitoring system which is installed in the ZPR-9 (Zero Power Reactor No. 9) facility at Argonne National Laboratory is described. The design and operational experience are discussed. This monitoring system utilizes particle size and density discrimination, alpha particle energy discrimination, and a background-subtraction techique operating in cascade to separate airborne-plutonium activity from other, naturally occurring, airborne activity. Relatively high sensitivity and reliability are achieved. (auth)
Date: January 1, 1975
Creator: Rusch, G.K.; McDowell, W.P. & Knapp, W.G.
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Zr and Mo isotopes in single presolar graphite grains : a record of stellar nucleosynthesis.

Description: Thirty-two individual graphite grains from the Murchison meteorite were analyzed for their Mo and/or Zr isotopic compositions by laser ablation resonant ionization mass spectrometry. {sup 96}Zr/{sup 94}Zr ratios range from 0.074 times to 10 times the solar value. Five grains have depletions in {sup 96}Zr, suggestive of the s-process, and two grains have extraordinary enrichments in {sup 96}Zr, suggestive of the r-process. Most graphite grains have close-to-terrestrial Mo isotopic imposition, but five have s-process Mo nucleosynthesis signatures.
Date: February 10, 1998
Creator: Nicolussi, G. K.
open access

Zr and Mo isotopic constraints on the origins of unusual types of presolar SiC grains.

Description: Although most presolar silicon carbide grains form in asymptotic giant branch red giant stars (the so-called mainstream grains) or supernovae (the X-grains), there are a number of other minor types of grains whose origin is less clear. The dominant mechanisms of heavy element nucleosynthesis, the s-process and r-process, are thought to occur mainly in AGB stars and supernovae, respectively [1], and the isotopic patterns in heavy elements in presolar grains can be used to constrain their origins. We have previously reported that mainstream SiC grains have strong enrichments in the s-process isotopes of Sr, Zr and Mo [2-5] and that X-grains have an unusual Mo isotopic composition that differs from s- and r-process expectations [6,7]. We report here the first measurements of Zr and Mo isotopes in several grains of other rare types that were found in the same mount as the mainstream and X-grains reported previously.
Date: March 1, 2000
Creator: Pellin, M. J.; Davis, A. M.; Calaway, W. F.; Lewis, R. S.; Clayton, R. N. & Amari, S.
open access

ZrH-reactor-technology program. Progress report, April-June 1974

Description: The report on the 2 kW(e) reactor-organic Rankine system was drafted. This report details the design parameters of a minimum weight, 2 kW(e) reactor-organic Rankine system. The system is designed for 5 years unattended life in space. The reactor produces 16.2 kW of thermal power with a NaK outlet temperature of 800/sup 0/F and a 200/sup 0/F ..delta..T. The reactor contains 19 fuel elements, 1.25'' in diameter by 10'' long, hydrided to an N/sub H/ of 6.35. The terrestrial applications effort was oriented towards the establishment of the feasibility of utilizing the zirconium hydride reactor technology in a subsea application for supplying electrical power to deep water, and other environmentally severe, oil well installations. The overall system concept is shown. The power system is composed of three basic modules (i.e., a reactor module, a generator module, and a heat rejection system) mounted on a barge. The barge is then towed to the installation site and submerged to mate with a previously installed seafloor foundation. An assembly/disassembly sequence was drafted detailing the steps required to assemble the reactor module and to disassemble it after 4 years of operations.
Date: July 12, 1974
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ZrO sub 2 and ZrO sub 2 /SiC particle reinforced-MoSi sub 2 matrix composites

Description: ZrO{sub 2}-MoSi{sub 2} and ZrO{sub 2}/SiC-MoSi{sub 2} composites were fabricated by hot pressing and hot pressing/HIP at 1700{degrees}C. No reactions between ZrO{sub 2}, SiC, and MoSi{sub 2} were observed. An amorphous silica glassy phase was present in all composites. Composites with unstabilized ZrO{sub 2} particles exhibited the highest room temperature fracture toughness, reaching a level three times that of pure MoSi{sub 2}. Both the room temperature toughness and 1200{degrees}C strength of ZrO/{sub 2}SiC-MoSi{sub 2} composites were higher than ZrO{sub 2}-MoSi{sub 2} composites, indicating beneficial effects of combined reinforcement phases. Low strength levels were observed at 1400{degrees}C due to the presence of the silica glassy phase. Elimination of glassy phases and refinements in microstructural homogeneity are processing routes important to the optimization of the mechanical properties of these types of composites. 18 refs., 7 figs.
Date: January 1, 1991
Creator: Petrovic, J. J.; Bhattacharya, A. K.; Honnell, R. E.; Mitchell, T. E. (Los Alamos National Lab., NM (United States)); Wade, R. K. (Arizona Materials Lab., Tucson, AZ (United States)) & McCellan, K. J. (Case Western Reserve Univ., Cleveland, OH (United States). Dept. of Materials Science and Engineering)
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THE ZrO$sub 2$-CaO-UO$sub 2$ CERAMIC FUEL FABRICATION FOR THE EBWR SPIKED CORE ELEMENTS. Final Report-Metallurgy Program 7.9.5

Description: A series of experiments was proposed in which the thermal output of the EBWR is increased to 100 Mw. The increase in thermal enengy will be accomplished by inserting 32 spike elements in the initial fuel core. The fuel selected for the spike elements was a cubic solid solution in the system ZrO/sub 2/- CaO- UO/ sub 2/. The ceramic fuel was fabricated in the form of pellets by compacting a mixture of U/sub 3/O/sub 8/, CaCO/sub 3/, and ZrO/sub 2/. The pressed pellets were sintered in air at 1675 deg C plus or minus 25 deg C to form a cubic solid solution having a composition of 9.01 wt.% UO/sub 2/ (93% enriched), 9.07 wt.% CaO, and 81.92 wt.% ZrO/sub 2/. The procedures used in forming the fuel pellets are described. Following fabrication, the pellets were loosely inserted into Zircaloy-2 tubes for subsequent assembly into fuel elements. (auth)
Date: May 1961
Creator: Lied, R. C.; Lynch, E. D. & Handwerk, J. H.
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