The Failure of Soft Law to Provide an Equitable Framework for Restitution of Nazi-looted Art

It is estimated that over 20% of the art in Europe was looted by the Nazi regime during World War II. Many pieces were taken by force from Jewish art dealers, and much of the property taken during this period of Nazi spoliation was never returned. Heirs of looted art are still filing claims for restitution in various courts, but the current global patchwork of statutes of limitations and the availability of the “good faith purchaser defense” in many jurisdictions can render proceedings confusing and unjust. This note explores the current state of the law regarding repatriation of Nazi-looted art, as well as contemporary examples that highlight the gaps and schisms in global restitution law. This note urges the signatories of non-binding international resolutions on the subject (i.e. the Washington Conference Principles and the Terezin Declaration) to create a designated administrator with the authority to make binding decisions regarding the claims of survivors and heirs who seek restitution of their looted art

Combining holographic patterning and block copolymer self-assembly to fabricate hierarchical volume gratings

The top-down nanomanufacturing technique is approaching its theoretic limits and processes such as e-beam lithography are extremely costly. In contrast, the bottomup method such as self-assembly can easily reach nanometer (even sub-nanometer) feature sizes. One drawback of self assembly, however, is the di culty to achieve large scale, defect-free structures. Combining the top-down and bottom-up methods in one system can lead to novel hierarchical nanostructures with tailored properties and this approach is generally referred to as \top-down helps bottom-up." While most of the existing systems deal with (quasi) two-dimensional patterning, partly due to the demands from semicomductor industry, in this dissertation, we demonstrate that three-dimensional, dynamic tunable, optical volume gratings can be manufactured via combining holographic patterning (HP) and block copolymer (BCP) self-assemblyinto one system.A number of semicrystalline homopolymers and BCP have been successfully patterned into one-dimensional and two-dimensional optical structures. In the onedimensional homopolymer case, a Bragg reector structure with continuous alternating layers of patterned polymer and the crosslinked resin were formed. The result of combining HP and BCP was a hierarchical structure fabricated from a homogenous solution in one step. HP formed 200 nm periodic lamellar structures, con ning a BCP to 100 nm domains. Subsequently, the BCP self-assembles into a lamellar structure with a period of 21 nm. This system provides an interesting basis for studying the thermo-optic behavior of the hierarchical volume grating formed by combiningtop-down manufacturing and bottom-up self-assembly. Upon heating and cooling a unique thermal switching occurred that can be attributed to the melting/phase separation that the BCP undergoes within the con ned region of the volume grating.There are at least ve advantages of this novel nanomanufacturing approach. First, two di erent nanomanufacturing techniques are seamlessly combined together and the resulting hierarchical structures span from a few nm to the 200 nm scale. Second, by combining these two techniques, the shortcomings of each method can be overcome. Third, this hierarchical structure can be fabricated in a few seconds. Fourth, the HP method enables the fabrication of a multiple layered structure, which is critical for three-dimensional nanodevice applications. Fifth, a variety of twodimensional and three-dimensional nanostructures can be readily achieved by changing the HP laser set-up and BCP structures.Ph.D., Materials Science and Engineering -- Drexel University, 200

Characterization of MOS Sensors for R-32 and R-454B Leaks

Owing to concerns about climate change, many jurisdictions are phasing out high global warming potential refrigerants in HVAC&R systems. Their near-term replacements are class A2L (mildly-flammable) refrigerants. Area monitoring detectors will be required for most future residential, commercial, and industrial HVAC systems that use these refrigerants. UL Standard 60335-2-40 requires these detectors to have a set-point of 25% of the lower flammability limit (LFL) and to detect the set-point within 10 s when exposed to a gas mixture at the LFL. Inexpensive detectors that meet these requirements do not exist, which has delayed the adoption of A2L refrigerants. A technology with good potential is based on metal-oxide semiconductors (MOS). MOS detectors are tested here, considering their response to leaks of R-32 and R-454B. They are characterized here for their sensitivity, response time, false alarms from contaminants, and poisoning. The sensors have good sensitivity with a steady-state output that is linear with respect to the logarithm of concentration. The sensors fail narrowly to meet the 10 s response time requirement for both R-32 and R-454B. The sensors do not alarm when exposed to the contaminants in the standard. However, several of the contaminants do poison the sensors, at least temporarily

Estimation of infection risk through airborne transmission in large open spaces with different air distributions

Respiratory diseases such as COVID-19 can be spread through airborne transmission, which is highly dependent on the airflow pattern of the studied room. Indoor air is typically not perfectly mixed even using a mixing ventilation, especially in large spaces. Airflow patterns in large open spaces such as hotel banquet rooms and open plan offices, are of particular concern, as these spaces usually accommodate more occupants and thus have the potential to spread diseases more rapidly leading to outbreaks. Therefore, understanding airflow patterns in large open spaces can help to estimate the detailed infection risk at certain locations in the space, which can prevent the spread of virus and track the potential new infections. This study estimated airflow patterns in a typical banquet room under theatre and banquet scenarios, and a large open plan office using computational fluid dynamics (CFD) simulations. Typical ventilation and air distribution approaches, as well as room layouts and occupant configurations in these scenarios were studied and applied in simulations. According to current results, the air distribution in a typical hotel banquet room with mixing ventilation can be very complicated, particularly for the banquet scenario. For a typical theatre scenario, under typical ventilation design, people sitting in the middle and lateral area were exposed to the highest infection risk. The front rows may be exposed to short-range transmission as well. For a banquet scenario, people sitting on the same table were more likely to be cross contaminated. But cross-table infection was still possible. The results can provide guidance on designing ventilation and air distribution approaches in large spaces with similar settings

Multizone Modeling of Airborne SARS-CoV-2 Quanta Transmission and Infection Mitigation Strategies in Office, Hotel, Retail, and School Buildings

Airborne transmission of SARS-CoV-2 mostly occurs indoors, and effective mitigation strategies for specific building types are needed. Most guidance provided during the pandemic focused on general strategies that may not be applicable for all buildings. A systematic evaluation of infection risk mitigation strategies for different public and commercial buildings would facilitate their reopening process as well as post-pandemic operation. This study evaluates engineering mitigation strategies for five selected US Department of Energy prototype commercial buildings (i.e., Medium Office, Large Office, Small Hotel, Stand-Alone Retail, and Secondary School). The evaluation applied the multizone airflow and contaminant simulation software, CONTAM, with a newly developed CONTAM-quanta approach for infection risk assessment. The zone-to-zone quanta transmission and quanta fate were analyzed. The effectiveness of mechanical ventilation, and in-duct and in-room air treatment mitigation strategies were evaluated and compared. The efficacy of mitigation strategies was evaluated for full, 75%, 50% and 25% of design occupancy of these buildings under no-mask and mask-wearing conditions. Results suggested that for small spaces, in-duct air treatment would be insufficient for mitigating infection risks and additional in-room treatment devices would be needed. To avoid assessing mitigation strategies by simulating every building configuration, correlations of individual infection risk as a function of building mitigation parameters were developed upon extensive parametric studies

Polymer crystallization/melting induced thermal switching in a series of holographically patterned Bragg reflectors

Holographic photopolymerization (H-P) is a simple, fast and attractive means to fabricate one-, two-and three-dimensional complex structures. Liquid crystals, nanoparticles and silicate nano-plates have been patterned into submicron periodical structures. In this article, we report fabrication of a one-dimensional reflection grating structure by patterning a semicrystalline polymer, polyethylene glycol (PEG), in Norland resin (thiol-ene based UV curable resin) matrix using the H-P technique. Sharp notches observed in the reflection grating of this Norland/PEG system indicate a finite Dn present in the system due to spatial segregation of the PEG and Norland resin. The notch position red shifts upon heating and the diffraction efficiency (ratio between diffraction and incident light intensity, DE) increases from y20% to 60% for the Norland 65/PEG 4600 grating. This dynamic behavior of the reflection grating is also fully reversible. The unique thermal switching behavior is attributed to the melting/formation of PEG crystals during heating/cooling. By employing different molecular weight PEGs which have different melting temperatures, a series of switching temperatures have been achieved. Since PEG can be easily coupled with a variety of functional groups, this research might shed light on fabricating multifunctional Bragg gratings using the H-P technique

Tuning Ion Conducting Pathways Using Holographic Polymerization

Polymer electrolyte membranes (PEMs) with high and controlled ionic conductivity are important for energy-related applications, such as solid-state batteries and fuel cells. Herein we disclose a new strategy to fabricate long-range ordered PEMs with tunable ion conducting pathways using a holographic polymerization (HP) method. By incorporating polymer electrolyte into the carefully selected HP system, electrolyte layers/channels with length scales of a few tens of nanometers to micrometers can be formed with controlled orientation and anisotropy; ionic conductivity anisotropy as high as 37 has been achieved