Seaborg's plutonium? A case study in nuclear                     forensics

ABSTRACT Recent nuclear forensics cases have focused primarily on plutonium (Pu) and uranium (U) materials. By definition however, nuclear forensics can apply to any diverted nuclear material. This includes neptunium (Np), an internationally safeguarded material like Pu and U, that could offer a nuclear security concern if significant quantities were found outside of regulatory control. This case study couples scanning electron microscopy (SEM) with quantitative analysis using newly developed specialized software, to evaluate a non-traditional nuclear forensic sample of Np. The results of the morphological analyses were compared with another Np sample of known pedigree, as well as other traditional actinide materials in order to determine potential processing and point-of-origin.

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National nuclear forensics libraries: a case study on benefits and possibilities for identification of sealed radioactive sources

Journal of Radioanalytical and Nuclear Chemistry ◽

10.1007/s10967-021-08100-4 ◽

2021 ◽

Author(s):

Anna Vesterlund ◽

Jody Canaday ◽

David B. Chamberlain ◽

Michael R. Curry ◽

Björn Sandström ◽

...

Keyword(s):

Nuclear Forensics ◽

The United States ◽

Regulatory Control ◽

United States Department ◽

Department Of State ◽

Measurement Results ◽

Subject Matter Expertise ◽

History Of

AbstractA National Nuclear Forensic Library (NNFL) is a useful nuclear forensics tool which consists of information and subject matter expertise on radioactive and nuclear (RN) materials produced, used or stored within a State. If RN material is found out of regulatory control the NNFL can be used as part of a nuclear forensics investigation to help identify whether or not the material is consistent with a country’s national holdings. In previous work, a number of signatures which can be useful to identify sealed sources of 241Am were investigated. To validate the measurement results, an official query concerning information about two of the previously investigated 241Am sources was sent to the United States Department of State, the international point-of-contact (POC) for the U.S. NNFL. The aim of this work is to show how data obtained in a characterization of a radioactive source can be used in conjunction with an NNFL to investigate the history of a source out of regulatory control.

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The Genesis and Internal Dynamics of El Salvador's People's Revolutionary Army, 1970–1976

Behavioral and Brain Sciences ◽

10.1017/s0140525x13009850 ◽

2014 ◽

Vol 38 (01) ◽

pp. 102-129

Author(s):

ALBERTO MARTÍN ÁLVAREZ ◽

EUDALD CORTINA ORERO

Keyword(s):

Latin America ◽

El Salvador ◽

Early Years ◽

Left Wing ◽

Internal Dynamics ◽

Internal Coherence ◽

The 1960S

AbstractUsing interviews with former militants and previously unpublished documents, this article traces the genesis and internal dynamics of the Ejército Revolucionario del Pueblo (People's Revolutionary Army, ERP) in El Salvador during the early years of its existence (1970–6). This period was marked by the inability of the ERP to maintain internal coherence or any consensus on revolutionary strategy, which led to a series of splits and internal fights over control of the organisation. The evidence marshalled in this case study sheds new light on the origins of the armed Salvadorean Left and thus contributes to a wider understanding of the processes of formation and internal dynamics of armed left-wing groups that emerged from the 1960s onwards in Latin America.

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Culture and the plasticity of perception

Behavioral and Brain Sciences ◽

10.1017/s0140525x19002887 ◽

2020 ◽

Vol 43 ◽

Author(s):

Michael Lifshitz ◽

T. M. Luhrmann

Keyword(s):

Cultural Context ◽

Sensory Experience ◽

Cultural Learning ◽

The World

Abstract Culture shapes our basic sensory experience of the world. This is particularly striking in the study of religion and psychosis, where we and others have shown that cultural context determines both the structure and content of hallucination-like events. The cultural shaping of hallucinations may provide a rich case-study for linking cultural learning with emerging prediction-based models of perception.

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Dual systems for all: Higher-order, role-based relational reasoning as a uniquely derived feature of human cognition

Behavioral and Brain Sciences ◽

10.1017/s0140525x19000451 ◽

2019 ◽

Vol 42 ◽

Author(s):

Daniel J. Povinelli ◽

Gabrielle C. Glorioso ◽

Shannon L. Kuznar ◽

Mateja Pavlic

Keyword(s):

Temporal Reasoning ◽

Higher Order ◽

Important Case ◽

Human Cognition ◽

Relational Reasoning ◽

Dual Systems ◽

First Order ◽

Reasoning System ◽

Role Based

Abstract Hoerl and McCormack demonstrate that although animals possess a sophisticated temporal updating system, there is no evidence that they also possess a temporal reasoning system. This important case study is directly related to the broader claim that although animals are manifestly capable of first-order (perceptually-based) relational reasoning, they lack the capacity for higher-order, role-based relational reasoning. We argue this distinction applies to all domains of cognition.

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Sociocultural memory development research drives new directions in gadgetry science

Behavioral and Brain Sciences ◽

10.1017/s0140525x19000979 ◽

2019 ◽

Vol 42 ◽

Author(s):

Penny Van Bergen ◽

John Sutton

Keyword(s):

Episodic Memory ◽

Autobiographical Memory ◽

Developmental Psychology ◽

Cross Cultural ◽

Memory Development ◽

Development Research ◽

Cultural Research ◽

New Directions ◽

Cross Cultural Research

Abstract Sociocultural developmental psychology can drive new directions in gadgetry science. We use autobiographical memory, a compound capacity incorporating episodic memory, as a case study. Autobiographical memory emerges late in development, supported by interactions with parents. Intervention research highlights the causal influence of these interactions, whereas cross-cultural research demonstrates culturally determined diversity. Different patterns of inheritance are discussed.

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Construction of plastic contact deformation maps on ceramics: a case study on aluminum nitride

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100165641 ◽

1996 ◽

Vol 54 ◽

pp. 636-637

Author(s):

D. L. Callahan

Keyword(s):

Plastic Deformation ◽

Aluminum Nitride ◽

Mechanical Response ◽

Three Dimensional ◽

Bright Field Image ◽

Perfectly Plastic ◽

Contrast Analysis ◽

Deformation Patterns

Modern polishing, precision machining and microindentation techniques allow the processing and mechanical characterization of ceramics at nanometric scales and within entirely plastic deformation regimes. The mechanical response of most ceramics to such highly constrained contact is not predictable from macroscopic properties and the microstructural deformation patterns have proven difficult to characterize by the application of any individual technique. In this study, TEM techniques of contrast analysis and CBED are combined with stereographic analysis to construct a three-dimensional microstructure deformation map of the surface of a perfectly plastic microindentation on macroscopically brittle aluminum nitride.The bright field image in Figure 1 shows a lg Vickers microindentation contained within a single AlN grain far from any boundaries. High densities of dislocations are evident, particularly near facet edges but are not individually resolvable. The prominent bend contours also indicate the severity of plastic deformation. Figure 2 is a selected area diffraction pattern covering the entire indentation area.

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