Singular Temperatures Connected to Charge Transport Mechanism Transitions in Perylene Bisimides from Steady-State Photocurrent Measurements

Perylene bisimides (PBIs) are n-type semiconducting and photogenerating materials widely used in a variety of optoelectronic devices. Particularly interesting are PBIs that are simultaneously water-soluble and liquid-crystalline (PBI-W+LC) and, thus, attractive for the development of high-performing easily processable applications in biology and “green” organic electronics. In this work, singular temperatures connected to charge transport mechanism transitions in a PBI-W+LC derivative are determined with high accuracy by means of temperature-dependent photocurrent studies. These singular temperatures include not only the ones observed at 60 and 110 °C, corresponding to phase transition temperatures from crystalline to liquid-crystalline (LC) and from LC to the isotropic phase, respectively, as confirmed by differential scanning calorimetry (DSC), but also a transition at 45 °C, not observed by DSC. By analyzing the photocurrent dependence simultaneously on temperature and on light intensity, this transition is interpreted as a change from monomolecular to bimolecular recombination. These results might be useful for other semiconducting photogenerating materials, not necessarily PBIs or even organic semiconductors, which also show transport behavior changes at singular temperatures not connected with structural or phase transitions.

Modelling and control of refrigeration systems: an account of a pedagogic experiment in a post-secondary technical course

Comunicação apresentada no CYTEF 2016/VIII Congresso Ibérico | VI Congresso Ibero-Americano de Ciências e Técnicas do Frio, 3-6 maio 2016, Coimbra, Portugal

Numerical and experimental investigation of structural stiffness influence on ratcheting convection cell in granular soils under cyclic loading

Lateral cyclic loaded structures in granular soils can lead to an accumulation of irreversible strains by changing their mechanical response (densification) and forming a closed convective cell in the upper layer of the bedding. In the present thesis the convective cell dimension, formation and grain migration inside this closed volume have been studied and presented in relation to structural stiffness and different loads. This relation was experimentally investigated by applying a cyclic lateral force to a scaled flexible vertical element embedded in dry granular soil. The model was monitored with a camera in order to derive the displacement field by means of the PIV technique. Modelling large soil deformation turns out to be difficult, using mesh-based methods. Consequently, a mesh-free approach (DEM) was chosen in order to investigate the granular flow with the aim of extracting interesting micromechanical information. In both the numerical and experimental analyses the effect of different loading magnitudes and different dimensions of the vertical element were considered. The main results regarded the different development, shape and dimensions of the convection cell and the surface settlements. Moreover, the Discrete Element Method has proven to give satisfactory results in the modelling of large deformation phenomena such as the ratcheting convective cell.

Loran-C signal analysis : final report /

"Report no. CG-D-4-80."

Intelligence professionalism in the Americas = Profesionalismo de inteligencia en las Américas /

Shipping list no.: 2004-0011-P.

A bibliography of selected AEC reports of interest to industry.

Includes bibliographical references.

Report.

Title varies slightly.

Design analyses.

At head of title: Engineering and design.

Collective protection against chemical, biological, and radiological warfare agents.

"1 Oct 58."

Urochnyi a polozhenii a na vsi e voobshche raboty, proizvodi a shchii a si a pri kri e posti a kh, grazhdanskikh zdanii a kh i gidrotekhnicheskikh sooruzhenii a kh.

Mode of access: Internet.

Test patterns NBS-28 and NBS-28A : random fault interconnect step coverage and other structures /

S/N 003-003-02297-7.

Accurate linewidth measurements on integrated-circuit photomasks /

"Supported by the Defense Advanced Research Projects Agency ... and the National Bureau of Standards."

Symposium on mathematics for engineering students being the proceedings of the joint sessions of the Chicago section of the American mathematical society and Section A, Mathematics, and Section D, Mechanical science and engineering of the American Association for the Advancement of Science held at the University of Chicago December 30 and 31, 1907.

Caption title: The American Association for the Advancement of Science. Section D--Mechanical science and engineering. Engineering Mathematics symposium.

Refrigeration for cryogenic sensors and electronic systems : proceedings of a conference held at the National Bureau of Standards, Boulder, CO, October 6-7, 1980 /

Item 247.

A standard for RF modulation factor /

Report No. FAA-RD-79-94." Microfiche.