869 resultados para Limit of meaning of a Scientific Theory


Relevância:

100.00% 100.00%

Publicador:

Resumo:

According to Karl Popper, widely regarded as one of the greatest philosophers of science in the 20th century, falsifiability is the primary characteristic that distinguishes scientific theories from ideologies – or dogma. For example, for people who argue that schools should treat creationism as a scientific theory, comparable to modern theories of evolution, advocates of creationism would need to become engaged in the generation of falsifiable hypothesis, and would need to abandon the practice of discouraging questioning and inquiry. Ironically, scientific theories themselves are accepted or rejected based on a principle that might be called survival of the fittest. So, for healthy theories on development to occur, four Darwinian functions should function: (a) variation – avoid orthodoxy and encourage divergent thinking, (b) selection – submit all assumptions and innovations to rigorous testing, (c) diffusion – encourage the shareability of new and/or viable ways of thinking, and (d) accumulation – encourage the reuseability of viable aspects of productive innovations.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Amonia borane (AB) has been identified as a potential candidate highcapacity hydrogen storage material. This work probes the adsorption and dissociation of AB inside and outside single-walled carbon nanotubes (SWCNTs) within the framework of density functional theory. The dissociation barriers of AB have been calculated and compared with that of the isolated AB molecule. On the basis of the present calculations, no notable improvement results from SWCNT confinement; on the contrary, the dissociation barrier slightly increases with respect to isolated AB.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The early warning based on real-time prediction of rain-induced instability of natural residual slopes helps to minimise human casualties due to such slope failures. Slope instability prediction is complicated, as it is influenced by many factors, including soil properties, soil behaviour, slope geometry, and the location and size of deep cracks in the slope. These deep cracks can facilitate rainwater infiltration into the deep soil layers and reduce the unsaturated shear strength of residual soil. Subsequently, it can form a slip surface, triggering a landslide even in partially saturated soil slopes. Although past research has shown the effects of surface-cracks on soil stability, research examining the influence of deep-cracks on soil stability is very limited. This study aimed to develop methodologies for predicting the real-time rain-induced instability of natural residual soil slopes with deep cracks. The results can be used to warn against potential rain-induced slope failures. The literature review conducted on rain induced slope instability of unsaturated residual soil associated with soil crack, reveals that only limited studies have been done in the following areas related to this topic: - Methods for detecting deep cracks in residual soil slopes. - Practical application of unsaturated soil theory in slope stability analysis. - Mechanistic methods for real-time prediction of rain induced residual soil slope instability in critical slopes with deep cracks. Two natural residual soil slopes at Jombok Village, Ngantang City, Indonesia, which are located near a residential area, were investigated to obtain the parameters required for the stability analysis of the slope. A survey first identified all related field geometrical information including slope, roads, rivers, buildings, and boundaries of the slope. Second, the electrical resistivity tomography (ERT) method was used on the slope to identify the location and geometrical characteristics of deep cracks. The two ERT array models employed in this research are: Dipole-dipole and Azimuthal. Next, bore-hole tests were conducted at different locations in the slope to identify soil layers and to collect undisturbed soil samples for laboratory measurement of the soil parameters required for the stability analysis. At the same bore hole locations, Standard Penetration Test (SPT) was undertaken. Undisturbed soil samples taken from the bore-holes were tested in a laboratory to determine the variation of the following soil properties with the depth: - Classification and physical properties such as grain size distribution, atterberg limits, water content, dry density and specific gravity. - Saturated and unsaturated shear strength properties using direct shear apparatus. - Soil water characteristic curves (SWCC) using filter paper method. - Saturated hydraulic conductivity. The following three methods were used to detect and simulate the location and orientation of cracks in the investigated slope: (1) The electrical resistivity distribution of sub-soil obtained from ERT. (2) The profile of classification and physical properties of the soil, based on laboratory testing of soil samples collected from bore-holes and visual observations of the cracks on the slope surface. (3) The results of stress distribution obtained from 2D dynamic analysis of the slope using QUAKE/W software, together with the laboratory measured soil parameters and earthquake records of the area. It was assumed that the deep crack in the slope under investigation was generated by earthquakes. A good agreement was obtained when comparing the location and the orientation of the cracks detected by Method-1 and Method-2. However, the simulated cracks in Method-3 were not in good agreement with the output of Method-1 and Method-2. This may have been due to the material properties used and the assumptions made, for the analysis. From Method-1 and Method-2, it can be concluded that the ERT method can be used to detect the location and orientation of a crack in a soil slope, when the ERT is conducted in very dry or very wet soil conditions. In this study, the cracks detected by the ERT were used for stability analysis of the slope. The stability of the slope was determined using the factor of safety (FOS) of a critical slip surface obtained by SLOPE/W using the limit equilibrium method. Pore-water pressure values for the stability analysis were obtained by coupling the transient seepage analysis of the slope using finite element based software, called SEEP/W. A parametric study conducted on the stability of an investigated slope revealed that the existence of deep cracks and their location in the soil slope are critical for its stability. The following two steps are proposed to predict the rain-induced instability of a residual soil slope with cracks. (a) Step-1: The transient stability analysis of the slope is conducted from the date of the investigation (initial conditions are based on the investigation) to the preferred date (current date), using measured rainfall data. Then, the stability analyses are continued for the next 12 months using the predicted annual rainfall that will be based on the previous five years rainfall data for the area. (b) Step-2: The stability of the slope is calculated in real-time using real-time measured rainfall. In this calculation, rainfall is predicted for the next hour or 24 hours and the stability of the slope is calculated one hour or 24 hours in advance using real time rainfall data. If Step-1 analysis shows critical stability for the forthcoming year, it is recommended that Step-2 be used for more accurate warning against the future failure of the slope. In this research, the results of the application of the Step-1 on an investigated slope (Slope-1) showed that its stability was not approaching a critical value for year 2012 (until 31st December 2012) and therefore, the application of Step-2 was not necessary for the year 2012. A case study (Slope-2) was used to verify the applicability of the complete proposed predictive method. A landslide event at Slope-2 occurred on 31st October 2010. The transient seepage and stability analyses of the slope using data obtained from field tests such as Bore-hole, SPT, ERT and Laboratory tests, were conducted on 12th June 2010 following the Step-1 and found that the slope in critical condition on that current date. It was then showing that the application of the Step-2 could have predicted this failure by giving sufficient warning time.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

This study explored how Korean men married to migrant women construct meaning around married life. Data were collected through in-depth interviews with 10 men who had had been married to migrant women for ≥ 2 years. Data collection and analysis were performed concurrently using a grounded theory approach. The core category generated was the process of sustaining a family unit. The men came to understand the importance of a distribution of power within the family in sustaining the family unit. Constituting this process were four stages: recognizing an imbalance of power, relinquishing power, empowering, and fine-tuning the balance of power. This study provides important insight into the dynamics of marital power from men's point of view by demonstrating a link between the way people adjust to married life and the process by which married couples adjust through the distribution and redistribution of power.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Aims and objectives. To present a novel approach to nurse stress by exploring the demand–control–support model with organisational justice through the lens of relational regulation theory. Background. Nursing is often stressful due to high demands and dissatisfaction with pay, which impacts the mental well-being and productivity of nurses. Design. A cross-sectional design. Methods. A validated questionnaire was sent to the work addresses of all nursing and midwifery staff in a medium-sized general acute hospital in Australia. A total of 190 nurses and midwives returned completed questionnaires for the analyses. Results. The multiple regression analyses demonstrated that the model applies to the prototypical context of a general acute hospital and that job control, supervisor support and outside work support improve the job satisfaction and mental health of nurses. Conclusions. Most importantly, supervisor support was found to buffer the impact of excessive work demands. Fairness of procedures, distribution of resources and the quality and consistency of information are also beneficial. Relational regulation theory is applied to these findings as a novel way to conceptualise the mechanisms of support and fairness in nursing. Relevance to clinical practice. The importance of nurses’ well-being and job satisfaction is a priority for improving clinical outcomes. Practically, this means nurse managers should be encouraging nurses in the pursuit of diverse relational activities both at work and outside work.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Due to the critical shortage and continued need of blood and organ donations (ODs), research exploring similarities and differences in the motivational determinants of these behaviors is needed. In a sample of 258 university students, we used a cross-sectional design to test the utility of an extended theory of planned behavior (TPB) including moral norm, self-identity and in-group altruism (family/close friends and ethnic group), to predict people’s blood and OD intentions. Overall, the extended TPB explained 77.0% and 74.6% of variance in blood and OD intentions, respectively. In regression analyses, common contributors to intentions across donation contexts were attitude, self-efficacy and self-identity. Normative influences varied with subjective norm as a significant predictor related to OD intentions but not blood donation intentions at the final step of regression analyses. Moral norm did not contribute significantly to blood or OD intentions. In-group altruism (family/close friends) was significantly related to OD intentions only in regressions. Future donation strategies should increase confidence to donate, foster a perception of self as the type of person who donates blood and/or organs, and address preferences to donate organs to in-group members only.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

ECA Best of Sustainability: Research, theory and practice by Elliott, Edwards, Davis and Cutter-MacKenzie collates a range of key articles focussing on sustainability from past editions of the Australasian Journal of Early Childhood and Every Child. Sustainable service operation and promoting children’s responsibility and care for the environment are now part of the National Quality Standards and more importantly, all early childhood services must engage with sustainability in this time of increasing global environmental concerns. The publication documents the best of research, theory and practice to date and questions where has early childhood education for sustainability come from and more importantly, where is it going? There are multiple possibilities for educators, researchers, policy makers and managers to take action in early childhood settings for an environmentally sustainable future.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The symptoms of psychiatric illness are diverse, as are the causes of the illnesses that cause them. Yet, regardless of the heterogeneity of cause and presentation, a great deal of symptoms can be explained by the failure of a single perceptual function – the reprocessing of ecological perception. It is a central tenet of the ecological theory of perception that we perceive opportunities to act. It has also been found that perception automatically causes actions and thoughts to occur unless this primary action pathway is inhibited. Inhibition allows perceptions to be reprocessed into more appropriate alternative actions and thoughts. Reprocessing of this kind takes place over the entire frontal lobe and it renders action optional. Choice about what action to take (if any) is the basis for the feeling of autonomy and ultimately for the sense-of-self. When thoughts and actions occur automatically (without choice) they appear to originate outside of the self, thereby providing prima facie evidence for some of the bizarre delusions that define schizophrenia such as delusional misidentification, delusions of control and Cotard’s delusion. Automatic actions and thoughts are triggered by residual stimulation whenever reprocessing is insufficient to balance automatic excitatory cues (for whatever reason). These may not be noticed if they are neutral and therefore unimportant whereas actions and thoughts with a positive bias are desirable. Responses to negative stimulus, on the other hand, are always unwelcome, because the actions that are triggered will carry the negative bias. Automatic thoughts may include spontaneous positive feelings of love and joy, but automatic negative thoughts and visualisations are experienced as hallucinations. Not only do these feel like they emerge from elsewhere but they carry a negative bias (they are most commonly critical, rude and are irrationally paranoid). Automatic positive actions may include laughter and smiling and these are welcome. Automatic behaviours that carry a negative bias, however, are unwelcome and like hallucinations, occur without a sense of choice. These include crying, stereotypies, perseveration, ataxia, utilization and imitation behaviours and catatonia.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

A new intellectual epoch has generated new enterprises to suit changed beliefs and circumstances. A widespread sentiment in both formal historiography and curriculum studies reduces the “new” to the question of how knowledge is recognized as such, how it is gained, and how it is represented in narrative form. Whether the nature of history and conceptions of knowledge are, or ought to be, central considerations in curriculum studies and reducible to purposes or elevated as present orientated requires rethinking. This paper operates as an incitement to discourse that disrupts the protection and isolation of primary categories in the field whose troubling is overdue. In particular, the paper moves through several layers that highlight the lack of settlement regarding the endowment of objects for study with the status of the scientific. It traces how some “invisible” things have been included within the purview of curriculum history as objects of study and not others. The focus is the making of things deemed invisible into scientific objects (or not) and the specific site of analysis is the work of William James (1842-1910). James studied intensely both child mind and the ghost, the former of which becomes scientized and legitimated for further study, the latter abjected. This contrast opens key points for reconsideration regarding conditions of proof, validation criteria, and subject matters and points to opportunities to challenge some well-rehearsed foreclosures within progressive politics and education.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

This Article examines the adverse impact theory of employment discrimination under Title VII. The author begins by discussing the development of adverse impact in the case law, and by scrutinizing its theoretical underpinnings. He demonstrates that Congress did not intend to mandate adoption of adverse impact theory when it established Title VII. The author then argues that the Courts have exceeded their authority under Title VII by embracing the theory of adverse impact. He concludes that the courts should therefore return to a narrower theory of employment discrimination, namely, a theory based on the legal concept of “intent.”

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Layered graphitic materials exhibit new intriguing electronic structure and the search for new types of two-dimensional (2D) monolayer is of importance for the fabrication of next generation miniature electronic and optoelectronic devices. By means of density functional theory (DFT) computations, we investigated in detail the structural, electronic, mechanical and optical properties of the single-layer bismuth iodide (BiI3) nanosheet. Monolayer BiI3 is dynamically stable as confirmed by the computed phonon spectrum. The cleavage energy (Ecl) and interlayer coupling strength of bulk BiI3 are comparable to the experimental values of graphite, which indicates that the exfoliation of BiI3 is highly feasible. The obtained stress-strain curve shows that the BiI3 nanosheet is a brittle material with a breaking strain of 13%. The BiI3 monolayer has an indirect band gap of 1.57 eV with spin orbit coupling (SOC), indicating its potential application for solar cells. Furthermore, the band gap of BiI3 monolayer can be modulated by biaxial strain. Most interestingly, interfacing electrically active graphene with monolayer BiI3 nanosheet leads to enhanced light absorption compared to that in pure monolayer BiI3 nanosheet, highlighting its great potential applications in photonics and photovoltaic solar cells.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Unlike standard applications of transport theory, the transport of molecules and cells during embryonic development often takes place within growing multidimensional tissues. In this work, we consider a model of diffusion on uniformly growing lines, disks, and spheres. An exact solution of the partial differential equation governing the diffusion of a population of individuals on the growing domain is derived. Using this solution, we study the survival probability, S(t). For the standard nongrowing case with an absorbing boundary, we observe that S(t) decays to zero in the long time limit. In contrast, when the domain grows linearly or exponentially with time, we show that S(t) decays to a constant, positive value, indicating that a proportion of the diffusing substance remains on the growing domain indefinitely. Comparing S(t) for diffusion on lines, disks, and spheres indicates that there are minimal differences in S(t) in the limit of zero growth and minimal differences in S(t) in the limit of fast growth. In contrast, for intermediate growth rates, we observe modest differences in S(t) between different geometries. These differences can be quantified by evaluating the exact expressions derived and presented here.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

- Problem Climate change is affecting the world in numerous ways such as increased temperatures, sea level rise, and increased droughts and floods. Governments worldwide, especially in the most vulnerable countries, are urged to seek better solutions for sustainable development. The construction industry and buildings have enormous impacts on humans and the environment, meaning green building must be one of the solutions. Government involvement is widely considered as one of the essential and most effective ways to promote green building and drive the construction market towards sustainability. This paper will review green building policy of the Pacific-Rim countries that are most vulnerable to climate change according to the recent Standard and Poor’s ranking, including: Cambodia, Vietnam, Fiji, Philippines, Papua New Guinea and Indonesia. Methodology: This paper will review policy related publications including journal and conference papers, portal websites of governments, legislation documents and reports of international organisations. It will focus on the policies and governmental instruments that support the adoption of green building practices. - Findings All six governments have launched climate change adaptation policies, showing a great concern regarding the damages caused by the phenomenon. All countries except Papua New Guinea have promulgated energy efficiency policy and programs which indirectly promote the adoption of green building practices. The comparison study shows that Philippines and Indonesia motivate the adoption of renewable energy generation, energy efficiency and green building through either financial or advocacy instruments, while other four countries tend to implement regulatory tools to mandate energy conservation. Through comparison, Cambodia and Vietnam – the two countries providing vision to develop green building - can learn from Philippines and Indonesia’s policy and instruments. - Research limitations Language differences between the countries and limit of formal sources may pose difficulties in searching for information. While much English language literature exists, sources from Cambodia, Philippines and Indonesia are less accessible. - Takeaway for practice As the paper provides more understanding about the supportive policy of those countries, it will introduce more opportunities for green property developers to invest in construction markets of those Pacific-Rim countries. - Originality There is little research reviewing green building supportive policies of developing and less-wealthy countries that are forecasted to be most vulnerable and most impacted by climate change. The originality of this paper lies in its investigation on how those countries intend to respond to this phenomenon and whether and to what extent they support the green building market by using policy tools.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Gravitaation kvanttiteorian muotoilu on ollut teoreettisten fyysikkojen tavoitteena kvanttimekaniikan synnystä lähtien. Kvanttimekaniikan soveltaminen korkean energian ilmiöihin yleisen suhteellisuusteorian viitekehyksessä johtaa aika-avaruuden koordinaattien operatiiviseen ei-kommutoivuuteen. Ei-kommutoivia aika-avaruuden geometrioita tavataan myös avointen säikeiden säieteorioiden tietyillä matalan energian rajoilla. Ei-kommutoivan aika-avaruuden gravitaatioteoria voisi olla yhteensopiva kvanttimekaniikan kanssa ja se voisi mahdollistaa erittäin lyhyiden etäisyyksien ja korkeiden energioiden prosessien ei-lokaaliksi uskotun fysiikan kuvauksen, sekä tuottaa yleisen suhteellisuusteorian kanssa yhtenevän teorian pitkillä etäisyyksillä. Tässä työssä tarkastelen gravitaatiota Poincarén symmetrian mittakenttäteoriana ja pyrin yleistämään tämän näkemyksen ei-kommutoiviin aika-avaruuksiin. Ensin esittelen Poincarén symmetrian keskeisen roolin relativistisessa fysiikassa ja sen kuinka klassinen gravitaatioteoria johdetaan Poincarén symmetrian mittakenttäteoriana kommutoivassa aika-avaruudessa. Jatkan esittelemällä ei-kommutoivan aika-avaruuden ja kvanttikenttäteorian muotoilun ei-kommutoivassa aika-avaruudessa. Mittasymmetrioiden lokaalin luonteen vuoksi tarkastelen huolellisesti mittakenttäteorioiden muotoilua ei-kommutoivassa aika-avaruudessa. Erityistä huomiota kiinnitetään näiden teorioiden vääristyneeseen Poincarén symmetriaan, joka on ei-kommutoivan aika-avaruuden omaama uudentyyppinen kvanttisymmetria. Seuraavaksi tarkastelen ei-kommutoivan gravitaatioteorian muotoilun ongelmia ja niihin kirjallisuudessa esitettyjä ratkaisuehdotuksia. Selitän kuinka kaikissa tähänastisissa lähestymistavoissa epäonnistutaan muotoilla kovarianssi yleisten koordinaattimunnosten suhteen, joka on yleisen suhteellisuusteorian kulmakivi. Lopuksi tutkin mahdollisuutta yleistää vääristynyt Poincarén symmetria lokaaliksi mittasymmetriaksi --- gravitaation ei-kommutoivan mittakenttäteorian saavuttamisen toivossa. Osoitan, että tällaista yleistystä ei voida saavuttaa vääristämällä Poincarén symmetriaa kovariantilla twist-elementillä. Näin ollen ei-kommutoivan gravitaation ja vääristyneen Poincarén symmetrian tutkimuksessa tulee jatkossa keskittyä muihin lähestymistapoihin.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The effective medium theory for a system with randomly distributed point conductivity and polarisability is reformulated, with attention to cross-terms involving the two disorder parameters. The treatment reveals a certain inconsistency of the conventional theory owing to the neglect of the Maxwell-Wagner effect. The results are significant for the critical resistivity and dielectric anomalies of a binary liquid mixture at the phase separation point.