The rush to accelerate: Early stages of nuclear physics research in Australia

2006 ◽  
Vol 36 (2) ◽  
pp. 213-241 ◽  
Author(s):  
R. W. HOME
Keyword(s):  
Nuclear Physics ◽  
Initial Period ◽  
Small Scale ◽  
Particle Accelerators ◽  
Postwar Period ◽  
Stages Of Development ◽  
Early Stages ◽  
Three Stages ◽  
Do It Yourself ◽  
Opening Up

ABSTRACT From the mid-1930s, Australian physicists, though few in number, sought to join the exciting new field of research then opening up in experimental nuclear physics. Such research was already, however, largely based on the use of particle accelerators, and to acquire one demanded money and resources on a scale unprecedented in Australian scientific experience. Australian attempts during the period 1935––1960 to build accelerators or to acquire them by other means are described. The difficulties that Australian physicists faced in this connection and the strategies by which they sought to overcome them are considered. Three stages of development are identified: an initial period of small-scale initiatives in the 1930s, a postwar period of ““do-it-yourself”” accelerator building, and finally a growing practice of buying machines ““off the shelf”” from commercial suppliers.

Formation of Dislocation Channels in Neutron Irradiated Molybdenum

1972 ◽  
Vol 30 ◽  
pp. 672-673
Author(s):  
S. Mahajan
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Ambient Temperature ◽  
Room Temperature ◽  
Channel Formation ◽  
Early Stages ◽  
Transmission Electron ◽  
Three Stages ◽  
Two Stages ◽  
Polycrystalline Molybdenum

The evolution of dislocation channels in irradiated metals during deformation can be envisaged to occur in three stages: (i) formation of embryonic cluster free regions, (ii) growth of these regions into microscopically observable channels and (iii) termination of their growth due to the accumulation of dislocation damage. The first two stages are particularly intriguing, and we have attempted to follow the early stages of channel formation in polycrystalline molybdenum, irradiated to 5×1019 n. cm−2 (E > 1 Mev) at the reactor ambient temperature (∼ 60°C), using transmission electron microscopy. The irradiated samples were strained, at room temperature, up to the macroscopic yield point.Figure 1 illustrates the early stages of channel formation. The observations suggest that the cluster free regions, such as A, B and C, form in isolated packets, which could subsequently link-up to evolve a channel.

Autómatas Celulares Aplicados al Comportamiento de Células de Cáncer Cervicouterino

2019 ◽  
Vol 6 (1) ◽  
pp. 44-49
Author(s):  
Tania Muñoz Jiménez ◽  
Aurora Torres Soto ◽  
María Dolores Torres Soto
Keyword(s):  
Cellular Automaton ◽  
Medical Model ◽  
Research Process ◽  
Simulation Algorithm ◽  
Stages Of Development ◽  
Literary Research ◽  
Migration Dynamics ◽  
Three Stages ◽  
And Migration ◽  
Best Parameters

En este documento se describe el desarrollo e implementación de un modelo para simular computacionalmente la dinámica del crecimiento y migración del cáncer cervicouterino, considerando sus principales características: proliferación, migración y necrosis, así como sus etapas de desarrollo. El modelo se desarrolló mediante un autómata celular con enfoques paralelo y secuencial. El autómata celular se basó en el modelo de Gompertz para simular las etapas de desarrollo de este cáncer, el cual se dividió en tres etapas cada una con diferentes comportamientos durante la simulación. Se realizó un diseño experimental con parámetros de entrada que se seleccionaron a partir de la investigación literaria y su discusión con médicos expertos. Al final del proceso de investigación, se logró obtener un algoritmo computacional de simulación muy bueno comparado con el modelo médico de Gompertz y se encontraron los mejores parámetros para su ejecución mediante un diseño factorial soportado estadísticamente. This paper describes the development and implementation of a model to computationally simulate the growth and migration dynamics of cervical cancer, considering its main characteristics: proliferation, migration and necrosis, as well as its stages of development. The model was developed by means of a cellular automaton with parallel and sequential approaches. The cellular automaton was based on the model of Gompertz to simulate the stages of development of this cancer, which was divided into three stages, each with different behaviors during the simulation. An experimental design was carried out with input parameters that were selected from literary research and its discussion with expert physicians. At the end of the research process, a very good simulation algorithm was obtained compared to the Gompertz medical model and the best parameters for its execution were found by means of a statistically supported factorial design.

The Artificial Pancreas in Cyborg Bodies

2020 ◽  
pp. 412-430
Author(s):  
Anthony Ryan Hatch ◽  
Julia T. Gordon ◽  
Sonya R. Sternlieb
Keyword(s):  
Glucose Sensor ◽  
Social Inequalities ◽  
Infusion Pump ◽  
Artificial Pancreas ◽  
Small Scale ◽  
Glucose Levels ◽  
Loop Design ◽  
Access To Health ◽  
Do It Yourself ◽  
And Control

The new artificial pancreas system includes a body-attached blood glucose sensor that tracks glucose levels, a worn insulin infusion pump that communicates with the sensor, and features new software that integrates the two systems. The artificial pancreas is purportedly revolutionary because of its closed-loop design, which means that the machine can give insulin without direct patient intervention. It can read a blood sugar and administer insulin based on an algorithm. But, the hardware for the corporate artificial pancreas is expensive and its software code is closed-access. Yet, well-educated, tech-savvy diabetics have been fashioning their own fully automated do-it-yourself (DIY) artificial pancreases for years, relying on small-scale manufacturing, open-source software, and inventive repurposing of corporate hardware. In this chapter, we trace the corporate and DIY artificial pancreases as they grapple with issues of design and accessibility in a content where not everyone can become a diabetic cyborg. The corporate artificial pancreas offers the cyborg low levels of agency and no ownership and control over his or her own data; it also requires access to health insurance in order to procure and use the technology. The DIY artificial pancreas offers patients a more robust of agency but also requires high levels of intellectual capital to hack the devices and make the system work safely. We argue that efforts to increase agency, radically democratize biotechnology, and expand information ownership in the DIY movement are characterized by ideologies and social inequalities that also define corporate pathways.

Particle accelerators in Mexico

2006 ◽  
Vol 36 (2) ◽  
pp. 297-309
Author(s):  
MARÍÍA DE LA PAZ RAMOS LARA
Keyword(s):  
Latin America ◽  
Nuclear Physics ◽  
Particle Accelerator ◽  
Particle Accelerators ◽  
Van De Graaff ◽  
Experimental Nuclear Physics

ABSTRACT The first Van de Graaff particle accelerator in Latin America was installed at the Universidad Nacional Autóónoma de Mééxico (UNAM) in 1952. This event marked the beginning of experimental nuclear physics, exclusively for peaceful purposes, in Mexico. The acquisition of this accelerator was fundamental for placing other accelerators into operation, which were used for both research and the resolution of national problems.

Comparative leaf development of aerial and aquatic growth forms of Myriophyllum aquaticum

Botany ◽  
2013 ◽  
Vol 91 (7) ◽  
pp. 421-430 ◽  
Author(s):  
M.D. Shafiullah ◽  
Christian R. Lacroix
Keyword(s):  
Apical Meristem ◽  
Epidermal Cells ◽  
The Other ◽  
Developmental Study ◽  
Growth Forms ◽  
Myriophyllum Aquaticum ◽  
Stages Of Development ◽  
Qualitative And Quantitative ◽  
Early Stages ◽  
Other Hand

Myriophyllum aquaticum (Vell.) Verdc. produces two morphologically different forms of leaves based on whether they are aerial or aquatic. The objective of this study was to determine whether there are any similarities or differences between these two growth forms during their early stages of development. A comparative developmental study of aerial and aquatic growth forms of M. aquaticum was conducted from a qualitative and quantitative perspective using a scanning electron microscope. The pattern of leaf and lobe initiation such as their origin and shape were similar in both growth forms until the fourth plastochron (stage P4). Differences between the two growth forms became evident from stage P5 onward, where a larger shoot apical meristem (SAM), elongated epidermal cells, shorter and slightly more numerous lobes, as well as the presence of appendage-like structures characterized aquatic growth forms. On the other hand, aerial growth forms had smaller SAM, bulb-like epidermal cells, and longer and slightly less numerous leaf lobes. Significant differences between growth forms were noted for parameters such as volume of SAM, length of terminal, first, and middle lobes, as well as the length from first to last lobes. The volume of the SAM of aquatic shoot tips was always greater than aerial forms. On the other hand, lobes of aerial forms were always longer than the aquatic counterpart during early stages of development. This study on the development of M. aquaticum shows that the aerial and aquatic growth forms diverge from their early stages of development.

XV. On the development of the parasitic isopoda

1878 ◽  
Vol 169 ◽  
pp. 505-521 ◽  
Keyword(s):  
The Body ◽  
The Other ◽  
Stages Of Development ◽  
Early Stages ◽  
Abdominal Appendages ◽  
Pair Of Antennae

The following paper contains an account of observations on the development of the species Cymothoa œstroides and C . parallela of Milne Edwards; but the forms of the young seem to show that several species are really included under these two names. In the early stages of development the only observable difference that exists between the embryos is one of size, but in the later stages they differ very markedly from each other in their external characters. From adult individuals answering the description of C . œstroides I have obtained four varieties of embryos: two with long antennae and two with short.* In the two former the first pair of antennae are but slightly longer than the head, while the second pair are longer than the body; the eyes are small. In one of the varieties thus characterised the abdominal appendages are fringed with long hairs (fig. 20), and in the other they are smooth.

Morphological variations of Phrosina semilunata Risso, 1822 juveniles (Crustacea: Amphipoda: Hyperiidea), new evidence from the Gulf of Mexico

Zootaxa ◽  
2021 ◽  
Vol 4995 (3) ◽  
pp. 594-600
Author(s):  
MARCO VIOLANTE-HUERTA ◽  
LAURA SANVICENTE-AÑORVE ◽  
MARGARITA HERMOSO-SALAZAR ◽  
AURORA MARRÓN-BECERRA
Keyword(s):  
Gulf Of Mexico ◽  
Monotypic Genus ◽  
Stages Of Development ◽  
Morphological Variations ◽  
Stages Of Growth ◽  
Early Stages ◽  
Southern Gulf Of Mexico ◽  
New Evidence ◽  
Lack Of Knowledge

Lack of knowledge of morphological variations during growth of amphipod crustaceans can result in misidentification of species. In this study, we advance the knowledge of morphological variations of juveniles of the monotypic genus Phrosina Risso, 1822 collected in the oceanic province of the southern Gulf of Mexico. The juveniles differed from the adults mainly in the morphology of pereopods 3 & 4 in that the carpal process is parallel to the propodus, also the rami of the pleopoda consist of only four segments, uropoda 3 are more lanceolate, and the uropoda bear a large prominent spine terminally. These morphological variations have not been described for the species previously. Therefore, the current observations enrich the description of P. semilunata in the early stages of growth and support the need for further taxonomical studiest that could help identify species at different stages of development.  

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