The effect of response mode and affective state on multiattribute decision-making

Response mode research shows that participants under a judgment response mode demonstrate more compensatory processing than participants under a choice mode. Research on affect and choice reveals that positive-affect participants display more noncompensatory examination of information than negative-affect participants. In the present study, participants viewed a film clip to induce positive or negative affect and made judgments or choices for a series of candidates for a university professor\u27s position. Results indicate a powerful effect for response mode across all dependent variables whereby judgment participants took more time, looked at more information, and showed less search variability than choice participants. The influence of affect, however, was undetectable, and several hypotheses are advanced to account for this finding

Effect of degree of cue separation and stimulus encoding method on cue sample size and learning rate

Response mode research shows that participants under a judgment response mode demonstrate more compensatory processing than participants under a choice mode. Research on affect and choice reveals that positive-affect participants display more noncompensatory examination of information than negative-affect participants. In the present study, participants viewed a film clip to induce positive or negative affect and made judgments or choices for a series of candidates for a university professor\u27s position. Results indicate a powerful effect for response mode across all dependent variables whereby judgment participants took more time, looked at more information, and showed less search variability than choice participants. The influence of affect, however, was undetectable, and several hypotheses are advanced to account for this finding

Strength improvement of cement pastes with cellulose -nanocrystals via short circuit diffusion

The influence of cellulose nanocrystals (CNCs) addition on the performance of cement paste is investigated. Our mechanical tests show an increase in the flexural strength of ~30% with only 0.2% volume of the as-received CNCs with respect to cement. However, the strength decreases at the high concentration region due to the agglomeration of CNCs. The ultrasonication is performed to disperse the CNCs and a maximum strength improvement of up to 50% is achieved. The relationship between the dispersion of CNCs and the strength of the cement paste is examined with rheological measurements. Isothermal calorimetry and thermogravimetric analysis show that the degree of hydration (DOH) of the cement paste is increased when CNCs are used. The first mechanism that explains the increased hydration is the steric stabilization, which is supported by rheological, heat flow rate measurements, microscopic imaging, and nanoindentation. A second mechanism is proposed as short circuit diffusion (SCD) to explain the increased hydration. SCD appears to increase cement hydration by increasing the transport of water from outside the hydration product shell (i.e., through the high density CSH) on a cement grain to the unhydrated cement cores. The DOH and flexural strength are measured for cement pastes with water reducing agent and CNC to verify this theory. Our results indicate that SCD is more dominant than steric stabilization

Early Detection of Joint Distress in Portland Cement Concrete Pavements

INDOT (as well as several surrounding states) have observed that certain concrete pavements may show a susceptibility to joint deterioration. Unfortunately, by the time that this joint deterioration is observed it is often too late and costly partial depth repairs are needed. The deterioration is generally occurring in the joint behind the backer rod and joint sealant; as such, it is difficult to detect even if one is standing directly above the joint. This project investigated the use of electrical resistivity and ground penetrating radar as two techniques to detect premature joint deterioration. The thought process was that if the joint deterioration is determined at an early stage, low cost corrective actions can be taken to extend the life of the concrete. The electrical response was measured for mortars subjected to a temperature cycle from 23 °C to -35 °C, with varying degrees of saturation, and varying salt concentrations. The resistivity increased as the degree of saturation was reduced due to the reduction in the volume of the conductive medium and increase in tortuosity. Changes in resistivity were detected when cracking occurred in the sample. The magnitude of these changes was similar to that detected using changes in the ultrasonic wave speed. Ground penetrating radar (GPR) was used effectively to detect fluid accumulation in the saw-cut joint behind the joint sealant. The typical GPR waveforms are however difficult and time consuming to interpret. A signal processing approach called, referred to as the CID, was used to obtain a single number that reflects the potential for fluid in the joint. Scalar waveform features and the computed CID can be used to estimate which joints may contain fluid thereby providing insights into which joint sealant sections may need to be repaired or when a sufficient number of joints may contain fluid suggesting a larger joint maintenance effort be performed to seal the joints or the concrete

Characterizing the Pore Structure of Carbonated Natural Wollastonite

This paper focuses on examining the pore structure of a cementitious paste made with a calcium silicate (wollastonite) that reacts with carbon dioxide and water to form a hardened solid. The pore structure of the hardened solid has been characterized using vapor sorption and desorption, low-temperature differential scanning calorimetry (LT-DSC), and scanning electron microscopy (SEM). The total porosity was also measured using mass measurement in oven-dry and vacuum-saturated conditions. Evidence exists that support the hypothesis that the solid has two main pore sizes: large macropores (\u3e10 nm) appear to form between the initial calcium silicate particles and small micropores (\u3c10 \u3enm) were found in the reacted silica gel. The bimodal nature of the pore structure was evident from the desorption and LT-DSC responses. The extent of reaction was also investigated and was found to be the result of the function of the raw material particle size: only particles with radius \u3c10 \u3eμm were found to have entirely reacted even in highly reacted systems. Moreover, the degree of reaction influenced the uniformity of reaction across the sample. Only the highly reacted system showed a uniform microstructure with continuous reaction products path and low porosity

Easily Accessible Experiments Demonstrating Interference

A brief but detailed description of simple experiments to be used in Physics classrooms

Surface and Uniaxial Electrical Measurements on Layered Cementitious Composites having Cylindrical and Prismatic Geometries

Electrical measurements are becoming a common method to assess the transport properties of concrete. For a saturated homogenous system, the surface resistance and the uniaxial resistance measurements provide equivalent measures of resistivity once geometry is appropriately taken into account. However, cementitious systems are not always homogenous. This article compares bulk and surface resistance measurements in cementitious materials intentionally composed of layered materials (i.e., layers with different resistivities). For this study, layered systems were composed of paste and mortar layers, representing the heterogeneity that can exist in the surface layers of field applications as a result of differences in moisture content, segregation, ionic ingress, carbonation, finishing operations, or ionic leaching. The objective of this article is to illustrate that these electrical measures can differ in layered systems (with sharp layer boundaries) and to demonstrate the impact of the surface layer properties on the estimation for the underlying material properties, for both cylindrical and prismatic specimens. Accounting for the effects of a surface layer requires a separate correction in addition to the overall specimen geometry corrections

A Mobile Concrete Laboratory to Support Quality Concrete, Technology Transfer, and Training

This report is a summary of work performed by the Mobile Infrastructure Materials Testing Laboratory (MIMTL) as a part of the Joint Transportation Research Program (JTRP) through SPR-3858. The development of the MIMTL began in February of 2014 and became fully operational by June of 2014. The MIMTL was deployed in the field for a total of 46 days. This report describes the activities of the MIMTL as of December 2015. The MIMTL was involved in the field testing of concrete bridges, concrete pavements, and asphalt pavements. This report describes the development of the mobile testing laboratory and provides some examples of how the MIMTL was used. The main highlights of the MIMTL’s implementation are as follows: The MIMTL’s high mobility and extensive inventory of research equipment allowed graduate students and researchers to conduct field studies on a wide range of infrastructure materials to accomplish the research objectives of their specific projects. More extensive details of the background, objectives, methods, findings, results and implementation from those projects can be found in the respective reports for those projects; The MIMTL supported a culture of safety that allowed students to work safely on jobsites in the State of Indiana ranging from roadside interstates, rural country roads, to ready-mix batching plants, often around heavy equipment, traffic, and in close quarters. During the operation of the MTIML described in this report, there were zero workplace accidents, and zero near misses reported; The MIMTL assisted in technology transfer between the infrastructure materials experts at Purdue University and contractors and suppliers in the State of Indiana. A wide range of new technologies evaluating infrastructure materials were utilized on a variety of projects. On each of these projects, MIMTL researchers educated industry personnel (contractors and suppliers), agency personnel (INDOT and local agencies), and consultants within the state. The MIMTL attended demonstrations with INDOT district and central office personnel to further highlight capabilities as well as the emerging technologies; The MIMTL was established a joint investment with partners in industry, local agencies, and INDOT. Operated by the Joint Transportation Research Program and the Local Technical Assistance Program as pay-per-use model, means this sustainable venture will offer services to researchers, industry, or agency entities that can cover the pay-per-use costs

The relationship between cellulose nanocrystal dispersion and strength

This paper studies the agglomeration of cellulose nanocrystals (CNCs) and uses ultrasonication to disperse CNCs in cement pastes in an attempt to improve strength. Rheological measurements show that when the concentration of CNCs exceeds 1.35% by volume in deionized water, agglomerates start to develop. This experimental finding is comparable to the value obtained from a geometrical percolation model (1.38% by volume). When the matrix phase (deionized water) is replaced with a simulated cement paste pore solution, the CNCs begin to agglomerate at a lower concentration (approximately 0.18% by volume). The CNC concentration of 0.18% corresponds to the concentration of CNCs in cement paste where the maximum strength is reached. Tip ultrasonication was found to effectively disperse the CNCs and the cement pastes obtained strength improvements of up to 50%, which is significantly better than the strength improvement of raw CNCs alone (20–30%).Keywords: Cellulose nanocrystal, Ultrasonication, Flexural strength, Short circuit diffusion, AgglomerationKeywords: Cellulose nanocrystal, Ultrasonication, Flexural strength, Short circuit diffusion, Agglomeratio

Gemini Planet Imager Observational Calibrations VI: Photometric and Spectroscopic Calibration for the Integral Field Spectrograph

The Gemini Planet Imager (GPI) is a new facility instrument for the Gemini Observatory designed to provide direct detection and characterization of planets and debris disks around stars in the solar neighborhood. In addition to its extreme adaptive optics and corona graphic systems which give access to high angular resolution and high-contrast imaging capabilities, GPI contains an integral field spectrograph providing low resolution spectroscopy across five bands between 0.95 and 2.5 $\mu$m. This paper describes the sequence of processing steps required for the spectro-photometric calibration of GPI science data, and the necessary calibration files. Based on calibration observations of the white dwarf HD 8049B we estimate that the systematic error in spectra extracted from GPI observations is less than 5%. The flux ratio of the occulted star and fiducial satellite spots within coronagraphic GPI observations, required to estimate the magnitude difference between a target and any resolved companions, was measured in the $H$-band to be $\Delta m = 9.23\pm0.06$ in laboratory measurements and $\Delta m = 9.39\pm 0.11$ using on-sky observations. Laboratory measurements for the $Y$, $J$, $K1$ and $K2$ filters are also presented. The total throughput of GPI, Gemini South and the atmosphere of the Earth was also measured in each photometric passband, with a typical throughput in $H$-band of 18% in the non-coronagraphic mode, with some variation observed over the six-month period for which observations were available. We also report ongoing development and improvement of the data cube extraction algorithm.Comment: 15 pages, 6 figures. Proceedings of the SPIE, 9147-30