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Diffraction-Grating-Free AlxIn1-xP/InAs Quantum Well Infrared Photodetector for Mid-Wavelength Infrared Imaging
No full textQuantum well infrared photodetector technology still offers the best stability, uniformity and reproducibility for thermal imaging applications. However, low quantum and conversion efficiencies of the standard quantum well infrared photodetector have been bottlenecks for wider utilization of these sensors. Another limitation of the quantum well infrared photodetector technology is the need for diffraction-grating establishing a barrier for pitch reduction. This paper reports strain-compensated diffraction-grating-free AlxIn1-xP/InAs quantum well infrared photodetector focal plane array operating in the mid-wavelength infrared band with characteristics much beyond the limits of standard quantum well infrared photodetectors. In spite of the absence of diffraction-grating, small-area (~120 μm2) pixels with 4.8 and 5.2 μm peak and cut-off wavelengths exhibited peak absorption quantum efficiency of 33%, peak specific detectivity of ~2×1011 cmHz1/2/W and background limited performance with f/2 aperture at temperatures exceeding 100 K. The photoconductive gain is adjustable in a wide range under almost constant sensitivity, and the peak conversion efficiency exceeds 50% which is much higher than that of the conventional grating-coupled quantum well infrared photodetector. The results of this work are important and promising for overcoming the bottlenecks of the quantum well infrared photodetector technology and facilitating wider employment of this important sensor including demanding imaging applications
Fragments of Belonging: Tracing Residential Memory in a Layered City
No full textThis paper explores the evolving relationship between residential environments and their inhabitants by tracing urban fragments in the multi-layered town of Pergamon (Bergama). As a continuously inhabited city shaped by centuries of transformation, Pergamon offers a complex landscape where spatial memory, material reuse, and lived experience intersect. Departing from the ancient practice of spoliation—the reuse of architectural fragments—the study adopts a contemporary and expanded reading of the concept. It proposes a critical inventory that does not merely document material remains but interprets spatial, symbolic, and experiential fragments as relational elements that mediate between past and present. In this broader framework, traces of former urban forms and residential life are viewed not only as physical artifacts but also as carriers of meaning, perception, and social memory. Rather than treating the city as a static collection of objects, this approach positions it as a dynamic assemblage where layers of adaptation, rupture, and continuity coexist. Whether material or intangible, fragments are read as active mediators shaping how residents understand, inhabit, and adapt their environments over time. By engaging with this layered urban condition through an interpretive inventory, the study reveals how meaning is embedded, displaced, and reconfigured across generations. It contributes to the understanding of how residential environments are formed not only through design and function but also through accumulated narratives, partial remains, and evolving human-place relationships embedded in the everyday urban fabric.</p
Cu doping of Sb2Se3 thin films via thermal evaporation: Tailoring structural and optical properties for enhanced photovoltaic performance
No full textIn this study, Cu-doped Sb2Se3 thin films were successfully grown using the thermal evaporation method, and their structural and optical properties were systematically investigated. Three different samples with thickness of ∼400 nm were analyzed: undoped, 1 %, and 2 % Cu-doped Sb2Se3. X-ray diffraction (XRD) analysis revealed well-defined peaks, confirming the orthorhombic crystalline nature of the films. Scanning electron microscopy (SEM) images showed a uniform surface morphology without any significant defects. The optical properties were examined through transmission measurements. The band gap energy determined by Tauc analysis decreased from 1.27 to 1.21 eV as the Cu doping increased from 0 % to 2 %, indicating that Cu incorporation modifies the electronic structure of Sb2Se3. Similarly, Urbach energy increased from 0.148 to 0.168 eV depending on Cu content, suggesting a rise in localized states due to increased structural disorder. These findings demonstrate that Cu doping influences the electronic structure and defect states of Sb2Se3, which is crucial for optimizing its performance in photovoltaic and optoelectronic applications
Tables turned on table talk
No full textEliminative structural realism is in line with mereological nihilism. This contrasts with reconciliatory, noneliminativist versions of structural realism, such as rainforest realism, which aim to accommodate quotidian ontology. Recently, the ordinary object ontology of rainforest realism has been defended by drawing on cognitive sciences. This paper critically examines philosophical arguments and scientific evidence, particularly from predictive processing, to argue that these sources do not support the ontology of ordinary objects but instead favour an organism-oriented form of eliminativist structural realism
Design, Integration, and Analysis of an Energy-Controlled Laser Electro-Opto-Mechanical System for a Realistic Laser Scene
No full textDynamic and precise control of laser energy is crucial for laboratory testing of advanced laser based electro-optical systems. We have developed and characterized a novel Laser Electro-Opto-Mechanical System (LEOMS) that addresses this need by providing pulse-to-pulse energy adjustment over a wide dynamic range (1 nJ to 2 mJ) at 1064 nm wavelength. LEOMS is a laser energy controller system which involves multi-polarizer optical architecture. This system utilizes an empirical calibration model for accurate attenuation results. The system also provides a dynamic energy stabilization or static energy calibration tool to enhance repeatability and accuracy in the long-term testing conditions. The real-time energy feedback tool of LEOMS allows more reliable and precise testing environment. The performance analysis has demonstrated that LEOMS offers a comprehensive solution for the cost-effective development and validation of next-generation advanced electro-optical systems
Dynamic In-Situ Testing of a 15-Year-Old Friction-Pendulum Base Isolation System
No full textBase isolation systems represent one of the most effective strategies for the seismic protection of buildings and infrastructure, applicable to both new constructions and retrofitting projects. Base isolation has received significant attention over the past few decades that led to remarkable improvements of this technology, resulting in the progressive deployment of better performing devices. Despite these significant advancements, the current understanding of the performance of isolated structures primarily stems from component-level testing of brand-new isolation bearings, while comprehensive studies on the long-term behavior of base isolation systems, particularly involving large groups of isolators in real-world applications, remain limited. The PASFIT project, introduced in this paper, addresses this knowledge gap by conducting extensive dynamic field testing of a 15-year-old base-isolated residential building equipped with 32 single-friction-pendulum bearings. This unique experimental program offers two key benefits: evaluating the performance of an entire group of base isolators under real-world conditions and providing valuable data for an in-depth analysis of the overall structural response of both the building and the isolation system, particularly in relation to material aging and natural deterioration over time. This paper presents an overview of the PASFIT project, detailing the efforts undertaken to successfully complete its ambitious experimental activities. Preliminary results are summarized at the end of the paper and contextualized within the broader objectives of quantifying isolation system degradation and validating its long-term reliability
