468 research outputs found
A test of functional theories of religion in a non-western sample
No full textScholars of religion have long pondered why humans believe in supernatural agents and participate in religious rituals. Some propose that religious features evolved as adaptations for a range of functions, such as alleviating insecurity, structuring social support and cooperating in large groups. Most work in this area has been conducted in Western, Educated, Industrialised, Rich and Democratic (WEIRD) countries, in times of relative resource abundance. This thesis uses religious survey and behavioural economic methods to investigate variation in religiosity and cooperation and test a range of functional explanations for religion in non-WEIRD societies, and in times of relative abundance and crisis. Fieldwork in 2014 in Christian and indigenous Kastom religious groups on the island of Tanna, Vanuatu, revealed that belief in an increasingly punitive deity predicted higher monetary offers to outgroup members but not coreligionists. Further fieldwork in 2015 allowed the same measures to be collected following the devastation of Cyclone Pam. Comparison of pre-vs post-cyclone data showed a general decrease in prosociality and more parochial giving to religious ingroup. Post-cyclone giving depended on the level and nature of affectedness; property damage predicted reduced prosociality and parochial giving, whereas exposure to others in distress predicted higher offers to coreligionists and outgroups. Cyclone experience did not predict changes in post-cyclone religiosity and religiosity did not buffer against perceived food insecurity. However, greater personal commitment to one's moralistic god predicted giving less to outgroup members and more parochial giving after the cyclone. Collaboration with the Cultural Evolution of Religion Consortium allowed investigation into functional explanations for putative gender differences in religiosity across a global sample of 14 societies. Women generally showed greater religiosity towards moralistic (but not local) gods. However, the clearest mediator of this gender gap was formal education, consistent with a general process of secularization rather than proposed functional accounts. Overall, the research presented in this thesis suggests individual experiences during a resource shock calibrate prosociality towards religious ingroups and outgroups. Individual religiosity predicted cooperation beyond the religious ingroup in times of plenty and more parochial giving in times of need. Less support was found for religion's function as a coping mechanism, be it in response to resource shocks or as an explanation of gender differences in religiosity
Engineering the Band Alignment in QD Heterojunction Films via Ligand Exchange
No full textColloidal quantum dots (QDs) allow great flexibility in the design of optoelectronic devices, thanks to their size-dependent optical and electronic properties and the possibility to fabricate thin films with solution-based processing. In particular, in QD-based heterojunctions, the band gap of both components can be controlled by varying the size of the QDs. However, control over the band alignment between the two materials is required to tune the dynamics of carrier transfer across a heterostructure. We demonstrate that ligand exchange strategies can be used to control the band alignment of PbSe and CdSe QDs in a mixed QD solid, shifting it from a type-I to a type-II alignment. The change in alignment is observed in both spectroelectrochemical and transient absorption measurements, leading to a change in the energy of the conduction band edges in the two materials and in the direction of electron transfer upon photoexcitation. Our work demonstrates the possibility to tune the band offset of QD heterostructures via control of the chemical species passivating the QD surface, allowing full control over the energetics of the heterostructure without requiring changes in the QD composition.ChemE/Opto-electronic Material
Quotient Disruption (QD): New Metric of Intelligence
No full textThis is a theoretical framework in cognitive science and strategic modeling. The author is not a medical professional.
En français :
Ce document présente un cadre théorique en sciences cognitives et modélisation stratégique. L'auteur n'est pas un professionnel de santé.
Résumé : Le Quotient de Disruption (QD) et la Loi de l'Inversion
Ce projet introduit le Quotient de Disruption (QD), modélisé par la loi de puissance :
QD=Qs(Qi)^∆
L'exposant ∆ est défini comme le produit de coefficients psychophysiologiques (Q_e, Q_m, Q_f). Contrairement aux modèles psychométriques linéaires classiques, cette formalisation intègre une phase d'inversion critique (∆< 0). Dans cet état (panique, fatigue extrême, auto-sabotage), le potentiel intellectuel (Qi) devient le diviseur de sa propre efficacité. Ce modèle mathématique explique ainsi l'implosion cognitive et la paralysie analytique des hauts potentiels face à des systèmes de friction intense.
English Version
Abstract: The Disruption Quotient (QD) and the Law of Power Inversion
This project introduces the Disruption Quotient (QD), modeled by the power law:
QD=Qs(Qi)^∆
The exponent ∆ is defined as the product of psychophysiological state coefficients (Q_e, Q_m, Q_f). Unlike traditional linear psychometric models, this formalization incorporates a critical inversion phase (∆< 0). In this state (e.g., acute panic, sleep deprivation, or self-sabotage), intellectual potential (Qi) becomes the divisor of its own efficiency. This mathematical model provides a rigorous explanation for cognitive implosion and analytical paralysis observed in high-potential individuals under conditions of intense systemic friction
Quantum dot solar cells and electrochemical doping of QD films
No full textQuantum dots (QDs) are nano-crystal semiconductors (1-100 nm) in which charge carriers (electrons and holes) are confined in all 3 dimensions by potential barriers that cause them to behave differently from conventional bulk semiconductors. QD research in the past decade has progressed rapidly, allowinga deeper understanding of the physics behind the functioning and the effective synthesis of such materials. The wide spread opto-electronic applications of such QD semiconductors in LEDs, lasers, electrochemistry and solar cells with the potential to outperform traditional bulk semiconductors has fuelled inspired research in this field.Quantum dot solar cells (QDSC) are solution-based third generation solar cells that possess the potential to overcome the Shockley-Queisser limit using multiple exciton generation (MEG). The large Bohr radius, wide bandgap tunability and large light absorption coefficients of PbS QDs have made them the most common material used in the absorber layer of such solar cells and shall also be the material used in this thesis. PbS QDs are used in conjunction with an n-type metal oxide to form a heterojunction that enhances charge separation at the interface. ZnO and TiO2 are common metal oxides used for this purpose while different synthesis methods of the same metal has been observed to show different results. While different research groups have used different metal oxide layers, there has been no systematic study on the interaction of the metal oxide layer synthesized by different methods with the absorber layer. Such a study could help improve understanding of the heterojunction interface and shallbe briefly looked into in this thesis. Another area of improvement in device performance is the depletion region across the heterojunction. Varying the doping of the n-type material affects the depletion width which has been explored in the past by adding impurity atoms to the metal oxide. However, theemergence of an alternate method to dope ZnO electrochemically has triggered an interesting novel pathway to integrate doped materials into solar cells. In this thesis, we have successfully fabricated PbS QD solar cells for the first time in TU Delft at the Synthesis lab of the Applied Sciences faculty withpower conversion efficiencies exceeding 5%. Additionally, a systematic study on the absorber layer and the metal oxide layer was also carried out to optimize the device performance and set protocols for any future work. Finally, electrochemical doping of the PbS absorber layer was attempted to developa precise doping mechanism for QD films.Electrical Engineering | Sustainable Energy Technolog
Thick film screen printed environmental and chemical sensor array reference electrodes suitable for subterranean and subaqueous deployments
No full textPurpose - Thick film environmental and chemical sensor arrays designed for deployment in both subterranean and submerged aqueous applications are reported.Design/methodology/approach - Various choices of materials for reference electrodes employed in these different applications have been evaluated and the responses of the different sensor types are compared and discussed. Findings - Results indicate that the choice of binder materials is critical to the production of sensors capable of medium term deployment (e.g. several days) as the binders not only affect the tradeoff between hydration time and drift but also have a significant bearing on device sensitivity and stability. Sensor calibration is shown to remain an issue with long term deployments (e.g. several weeks) but this can be ameliorated in the medium term with the use of novel device fabrication and packaging techniques.Originality/value – The reported results indicates that is possible through careful choice of materials and fabrication methods to achieve near stable thick film reference electrodes that are suitable for use in solid state chemical sensors in variety of different application areas
ELECTRIC CONDUCTION IN METALLIC AG PARTICLES - CS2O SEMICONDUCTOR THIN-FILMS
No full textMaterials Science, Coatings & FilmsPhysics, AppliedSCI(E)2ARTICLE2371-375
An Ostrowski Type Inequality for Weighted Mappings with Bounded Second Derivatives
No full textA weighted integral inequality of Ostrowski type for mappings whose second derivatives are bounded is proved. The inequality is extended to account for applications in numerical integration
OPTICAL-PROPERTIES OF CS2O AND AG-CS2O THIN-FILMS
No full textMaterials Science, Coatings & FilmsPhysics, AppliedSCI(E)3ARTICLE41960-1964
The role of collective motion in examples of coarsening and self-assembly
No full textThe simplest prescription for building a patterned structure from its constituents is to add particles, one at a time, to an appropriate template. However, self-organizing molecular and colloidal systems in nature can evolve in much more hierarchical ways. Specifically, constituents (or clusters of constituents) may aggregate to form clusters (or clusters of clusters) that serve as building blocks for later stages of assembly. Here we evaluate the character and consequences of such collective motion in a set of prototypical assembly processes. We do so using computer simulations in which a system's capacity for hierarchical dynamics can be controlled systematically. By explicitly allowing or suppressing collective motion, we quantify its effects. We find that coarsening within a two dimensional attractive lattice gas (and an analogous off-lattice model in three dimensions) is naturally dominated by collective motion over a broad range of temperatures and densities. Under such circumstances, cluster mobility inhibits the development of uniform coexisting phases, especially when macroscopic segregation is strongly favored by thermodynamics. By contrast, the assembly of model viral capsids is not frustrated but is instead facilitated by collective moves, which promote the orderly binding of intermediates consisting of several monomers
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