The effective mass of atom-radiation field system and the cavity-field Wigner distribution in the presence of a homogeneous gravitational field in the Jaynes-Cummings model

The effective mass that approximately describes the effect of a classical homogeneous gravitational field on an interacting atom-radiation field system is determined within the framework of the Jaynes-Cummings model. By taking into account both the atomic motion and gravitational field, a full quantum treatment of the internal and external dynamics of the atom is presented. By solving exactly the Schrodinger equation in the interaction picture, the evolving state of the system is found. Influence of a classical homogeneous gravitational field on the energy eigenvalues, the effective mass of atom-radiation field system and the Wigner distribution of the radiation field are studied, when initially the radiation field is prepared in a coherent state and the two-level atom is in a coherent superposition of the excited and ground states.Comment: 12 pages, 9 figure

Impact of Selected Infrared Wavelengths on Inactivation of Microbes on Rough Rice

Formation of harmful microbes and their associated mycotoxins on rough rice during storage presents negative socioeconomic impacts to producers and consumers. The objective for this study was to investigate the impact of treating rough rice with selected infrared (IR) wavelengths at different IR intensities and heating durations, followed by a tempering step for further inactivation of microbes (mold and bacteria) on the grain. Freshly-harvested long-grain, hybrid, rough rice (XL 745) with initial moisture content (IMC) of 18.4% wet basis (w.b.) was used. Two-hundred grams (200 g) samples of rice were treated at different IR wavelengths (λ), 3.2, 4.5, and 5.8 μm for 10, 20 and 30 seconds (s); at product-to-emitter gaps of 110, 275, and 440 mm. This was then followed by tempering the grain; putting samples in air-tight jars and holding at a constant temperature of 60 oC for 4 hours (h). Inoculated Petrifilm plates for mold and bacterial analyses were incubated at 25 oC for 120 h and 35 oC for 48 h respectively. Samples treated at wavelength 3.2 μm (product-to-emitter gap 110 mm) for 30 s showed the greatest reduction in mold and bacterial load; approximately 3.11 and 1.09 log reduction in the colony forming unit of mold and bacteria, respectively. Microbial analysis was performed on the rice prior to tempering, then all of the rice was tempered and microbial analysis was performed again to analyze the effectiveness of a tempering step. Tempering treatment further reduced the microbial load at each IR treatment condition. Molds showed more susceptibility to the IR decontamination than bacteria. This study provides useful information on the effectiveness of IR heating and tempering on microbial inactivation on rough rice

نگاهی به رفتارهای نامحترمانه در محیط های آموزشی از دیدگاه اساتید و دانشجویان A Glance at Students and Faculty Members Perceptions of Incivil Behavior in Educational Setting

رفتارهای نامحترمانه در محیط های آموزشی می تواند به شدت یاددهی و یادگیری را مختل نماید و به ایجاد تناقض و اضطراب بین استاد و دانشجو منجر گردد. هدف از این مقاله بررسی دیدگاه دانشجویان و اساتید دانشگاه علوم پزشکی گلستان در مورد رفتارهای نامحترمانه و تهدید آمیز در محیط های آموزشی می باشد

Post-Earthquake Structural Damage Assessment Through Point Cloud Data

Structural damage assessment following an extreme event can provide valuable information and insight into unanticipated damage and failure modes to improve design philosophies and design codes as well as reduce vulnerability. Oftentimes, structural engineers create finite element models (FEM) of the structure in which numerous model parameters require calibration to simulate the current state. This information may include structural plan details (geometry), material characteristics (strength and stiffness parameters), as well as observed damage patterns (cracks, spalling, etc.). Ground-based lidar (GBL) scans and Structure-from-Motion (SfM) can rapidly capture dimensionally accurate point clouds of the structure or facility of interest. Furthermore, point clouds can used to efficiently document perishable structural damage data digitally prior recovery or retrofit efforts. Within these point clouds, information can be extracted to objectively locate damage patterns in non-temporal datasets. Localization and quantification of damage can serve to update models with high fidelity within forensic investigations as well as to estimate the remaining structural capacity. In this work, an algorithm based on two spatially invariant geometrical features was used to identify and quantify structural damage from point cloud data for two case study buildings. The first case-study building is an 18-story high-rise condominium building that was significantly damaged during the 2015 Gorkha (Nepal) Earthquake. The damage included significant cracks in partition walls, unreinforced masonry infill walls, and section-loss within coupling beams and staircases at various levels. The second case-study structure, from the same earthquake event, is a five-tiered pagoda style temple built using timber beams and thick brick masonry walls. The temple sustained moderate damage where shear cracks developed at lower levels and seam of the wall piers. Through the developed damage detection method, cracking, concrete spalling, and loss of cross-section within the point cloud data of the nonstructural and structural elements are quantified

LiDAR Scanning with Supplementary UAV Captured Images for Structural Inspections

Structural assessment using remote sensing technologies can be performed efficiently and effectively using such technologies as LiDAR (light detection and ranging). LiDAR can be employed for various structural assessments, such as as-built conditions for a newly constructed facility, routine inspection during its service life, or structural collapse evaluation after a natural hazard or extreme event. However, the main disadvantage of LiDAR is that it is a line-of-sight technology that can result in significant occlusions. Architectural or structural components can be partially or fully occluded by another object with respect to the location of the laser scanner. Supplemental photogrammetry techniques, such as structure from motion (SfM), can be introduced into the workflow to reduce the occlusion in the final result. Since high-resolution cameras have the ability to be mounted on unmanned aerial vehicles (UAVs), typical areas of occlusion associated with ground-based LiDAR and supported structural coverings (e.g. roof or bridge deck) can be reconstructed. In this approach, aerial SfM is selected due to the low investment and operational costs in comparison to airborne LiDAR. This paper demonstrates the techniques and results of both LiDAR and aerial SfM for a case study building. Images captured with a UAV supplement the collected LiDAR and allow for a holistic scene reconstruction. The benefits of deployment of a combined remote sensing platform, such as this, are demonstrated in the case of reconnaissance in the aftermath of extreme events