Search results for "Significant difference"
showing 10 items of 337 documents
Correlations between a Hawking particle and its partner in a 1+1D Bose-Einstein condensate analog black hole
2020
The Fourier transform of the density-density correlation function in a Bose-Einstein condensate (BEC) analog black hole is a useful tool to investigate correlations between the Hawking particles and their partners. It can be expressed in terms of $⟨{^{\mathrm{out}}\stackrel{^}{a}}_{\mathrm{up}}^{\mathrm{ext}}\text{ }\text{ }{^{\mathrm{out}}\stackrel{^}{a}}_{\mathrm{up}}^{\mathrm{int}}⟩$, where ${^{\mathrm{out}}\stackrel{^}{a}}_{\mathrm{up}}^{\mathrm{ext}}$ is the annihilation operator for the Hawking particle and ${^{\mathrm{out}}\stackrel{^}{a}}_{\mathrm{up}}^{\mathrm{int}}$ is the corresponding one for the partner. This basic quantity is calculated for three different models for the BEC f…
Performance of the cost-effective Planacon ® MCP-PMTs in strong magnetic fields
2020
Abstract We present the behavior of the cost-effective Planacon MCP-PMTs with 25 μ m pore diameter in the presence of axial magnetic fields up to 0.5 T. Having a batch of 62 devices of the same type, two MCP-PMTs were selected and their gain variation measured in different magnetic fields. These two otherwise identical devices satisfied the selection criteria by requiring the lowest (1.15 kV) and one of the highest (1.4 kV) bias voltage values to achieve a given gain. Both MCP-PMTs have a nearly identical tolerance of the strong magnetic field despite the significant difference in the bias voltage. This clarifies the mechanism of the B-field influence on the MCP-PMT gain, emphasizing the im…
Longitudinal and transverse momentum distributions of 9Li fragments from break-up of 11Li
1995
7 pages, 3 figures, 1 table.
The Rhetoric and Relevance of IS Research Paradigms: Conceptual Foundations and Empirical Evidence
2006
This paper discusses the relevance of IS research with respect to the rhetoric associated with the three major IS research paradigms in use - positivism, constructivism/interpretivism and critical research. The conceptual discussion is framed in terms of the following dimensions: ontological, epistemological and methodological assumptions, relationship between theory and practice, and the role of the researcher in the research process. Based on this discussion, we propose a conceptual model to study the relationship between the espoused philosophical assumptions of researchers and the degree of relevance of researchers’ knowledge claims. This conceptual model was evaluated with data obtaine…
Prevalence of maxillary canine impaction in skeletal Class III malocclusions compared to Class I malocclusions
2019
Background The aim of the present investigation was to evaluate if an orthodontic population of Class III malocclusion patients shows a different prevalence of maxillary canine impaction than Class I subjects. Material and methods Fifty-eight subjects were retrospectively selected and assigned to the Class I group (n= 32) or the Class III group (n= 26), depending on the ANB and WITS values. Lateral cephalograms were used to collect angular and linear measurements that described the skeletal and dental maxillary features of the subjects, while orthopantomography was used to assess the impaction or the correct eruption of the maxillary canines. An independent samples T-test or a Mann-Whitney …
Blood absorption capacity of different xenograft bone substitutes. An in-vitro study
2019
Background Commercially available xenograft blocks, claim to have adequate characteristics to interact with biological media and thus permitting biological fluid absorption. The objective of this in vitro study was to compare the blood absorption capacity of four different xenograft block materials of different composition of collagen and porosity. Material and Methods Four brands of xenograft block materials were used (NuOss®, Bio-Oss®, Osteobiol® and Smartbone®). Five samples of each brand were analyzed, making a total of 20 tests. Human blood was used as the absorption liquid for the present experiment. The time period, in which the block remains in contact with the blood, was registered…
Marginal adaptation of three-unit interim restorations fabricated by the CAD-CA systems and the direct method before and after thermocycling
2020
Background Limited information is available regarding the marginal adaptation of three-unit interim restorations fabricated by different techniques from different materials. Also, the efficacy of computer-aided design/computer-aided manufacturing (CAD-CAM) systems for their fabrication is still questionable. This study aimed to assess the marginal adaptation of three-unit interim restorations fabricated by the CAD-CAM systems and the direct method from different materials before and after thermocycling. Material and Methods A sound mandibular second premolar and a second molar were prepared for a three-unit all-ceramic restoration. Metal dies were fabricated to simulate a case of mandibular…
Hypothetical influence of non-indexed Spanish journals on the impact factor of radiological journals
2004
Abstract Objective: The aim of this study was to analyze the hypothetical changes in the 2001 impact factor of 52 radiological journals included in the Science Citation Index–Journal Citation Reports by also counting cites proceeding from 73 Spanish journals on different medical specialties. Also, to estimate the possible impact factor of the official Spanish radiology journal, Radiologia , not included in this database. Materials and methods: A modified 2001 impact factor of 52 radiological journals and Radiologia was obtained by adding the number of cites in 1999 and 2000 from the medical Spanish journals. Data were obtained by consulting the 2001 edition of the Journal Citation Reports i…
Spanish Production of Research Articles on Diagnostic Imaging in Cardiology and Radiology (1994-1998)
2004
Introduction and objectives. The aim of this study was to evaluate the production of research papers by Spanish authors on diagnostic imaging published in the official journals of two Spanish scientific societies (REVISTA ESPANOLA DE CARDIOLOGIA and Radiologia) between 1994 and 1998, and to compare publication rates with those of research papers published in foreign cardiological and radiological journals included in Journal Citation Reports. Material and method. Specific search profiles were devised to retrieve items from the Indice Medico Espanol (IME) and MEDLINE databases. The impact factor for non-Spanish journals devoted to different specialties was normalized for the number of papers…
Younger bank voles are more vulnerable to avian predation
2008
The importance of predation on prey populations is mainly determined by the number of eaten prey. However, the total impact of predation might also be determined by the selection of certain prey individuals, e.g., different sexes or age categories. Here we tested selective predation by an avian predator, the pygmy owl ( Glaucidium passerinum (L., 1758)), on bank voles ( Myodes ( Clethrionomys ) glareolus (Schreber, 1780)). We compared the sex, age, and mass of hoarded prey with the animals snap-trapped from the field. There were no differences in the sex ratio between hoarded bank voles and those available in the field. However, hoarded voles were significantly younger than ones in the fie…