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The improvements made to ultra-thin windows for X-ray detectors in recent years have allowed for the detection of elements as light as lithium. However, their use with particle induced X-ray emission (PIXE) spectroscopy typically requires the addition of an absorber thick enough to prevent backscattered ions from reaching the detector. This also prevents lower energy (< 1 keV) X-rays from reaching the detector. By using a magnetic field to deflect backscattered ions away, the absorber can be eliminated, allowing for the detection of ultra-low energy X-rays. At the Ion Beam Laboratory of the University of North Texas, a prototype PIXE system using a magnetic deflector has been developed to allow for the detection and measurement of X-rays from light elements using a silicon drift X-ray detector with an ultra-thin window. With an average magnetic flux density of 0.88 T along the center, backscattered protons of an energy up to 1.22 MeV were successfully deflected away from the X-ray detector. Light element PIXE was performed with a 1 MeV proton beam on manganese oxide, sodium chloride and a Hibiscus rosa-sinensis leaf. Elements of 5 ≤ Z ≤ 30 were successfully detected. 

PIXE analysis was conducted on p8 fisher brand filter paper samples soaked in elemental standard solutions to determine the minimum detectable levels of Al, Si, P, S, Cl, K, Ca, Cr, Fe, Ni, Cu, and Se. All samples were analyzed with beam parameters of 2 µC incident charge, and beam current of less than 2 nA at 2 MeV beam energy. Minimum detectable levels were obtained by analyzing the x-ray spectrum in the GeoPIXE analysis package, and the data for each element would be averaged over all collected spectra. The minimum detectable level in parts per million was found to be on average 9.59 for Al, 4.6 for Si, 3.23 for P, 2.27 for S, 1.82 for Cl, 1.15 for K, 0.88 for Ca, 0.51 for Cr, 0.07 for Mn, 0.54 for Fe, 1.59 for Ni, 2.0 for Zn, 1.55 for Cu, and 6.5 for Se. Minimal deviation from the averaged values was observed, except in cases where samples contained high concentrations of elements with overlapping X-ray energies. 

Particulate matter (PM) found in the air is one of the major sources of pollution and air‐borne diseases. Therefore, it is imperative to examine the elemental concentration distribution of the PM to identify the pollutant sources. In this study, it has demonstrated the capabilities of micro‐particle‐induced X‐ray emission (micro‐PIXE) spectroscopy in quantitative analysis of air samples collected from the Old Delhi outdoor market and indoor locations in the Panjab University hostel in the winter months. A 2‐million electronvolts energetic scanning proton micro‐beam (diameter ≈1 µm²) is used in micro‐PIXE experiments generating high‐resolution elemental maps of different regions of interest (ROI). Micro‐PIXE along with the GeoPIXE analysis provides a non‐destructive, standard‐less, and ng/mg level‐sensitive tool for the investigation of elemental distributions and highlighting pixels, which correlates to specific concentration ratios between elements at ROIs, thereby enabling a comprehensive understanding of the source of each elemental particulate. Si, Ca, and K detected in indoor PM suggest the source to soil erosion and crop burning, while high S levels in outdoor PM are primarily associated with coal power plants. Additionally, Sc, Ti, Cr, Mn, and Zn are found in outdoor samples, while indoor locations also contained trace amounts of V, Co, and Cu. 

Metal halide perovskite (MHP) solar cells are promising aerospace power sources given their potential as inexpensive, lightweight, and resilient solar electricity generators. Herein, the intrinsic radiation tolerance of unencapsulated methylammonium lead iodide/chloride (CH3NH3PbI3-xClx) films was isolated. Spatially resolved photoluminescence (PL) spectroscopy and confocal microscopy revealed the fundamental defect physics through optical changes as films were irradiated with 4.5 MeV neutrons and 20 keV protons at fluences between 5×1010 and 1×1016 p+/cm2. As proton radiation increased beyond 1×1013 p+/cm2, defects formed in the film, causing both a decrease in photoluminescence intensity and a 30% increase in surface darkening. All proton irradiated films additionally exhibited continuous increase of energy bandgaps and decreasing charge recombination lifetimes with increasing proton fluences. These optical changes in the absorber layer precede performance declines detectable in standard current-voltage measurements of complete solar cell devices and therefore have the potential of serving as early indicators of radiation tolerance. 

We have investigated the concentration and correlation between the macro and micro-elements found in an herbal plant named Ocimum sanctum (Tulsi) leaf, using Particle-Induced X-ray Emission (PIXE) spectroscopy. The leaf area was analyzed with a 2 MeV scanning proton micro-beam with a spot size of ~ 1 square micrometer. This study is focused on exploring the correlation between the elemental maps generated using X-ray spectra with micro-PIXE. Two types of correlations i.e., elemental, and concentration-phase correlations were examined. The elemental maps are used to find the relation between the spatial distribution of the elements present in the scanned region while the correlation maps help in understanding which phase corresponds to the region of selected concentration ratios. All the elemental concentrations were determined with the detection limits in ng/mg. The analysis of macro-elements showed that the potassium concentration was highest and phosphorus exhibited the lowest concentration whereas iron was found to be highest in the category of trace or microelements. Moreover, broad-beam runs were also performed on the samples to examine the trend for elemental concentrations. 

We report on an examination of mobile ion concentration (N₀) in perovskite solar cells (PSCs) as a function of temperature and device architecture. 

This article presents a novel hardware-assisted distributed ledger-based solution for simultaneous device and data security in smart healthcare. This article presents a novel architecture that integrates PUF, blockchain, and Tangle for Security-by-Design (SbD) of healthcare cyber–physical systems (H-CPSs). Healthcare systems around the world have undergone massive technological transformation and have seen growing adoption with the advancement of Internet-of-Medical Things (IoMT). The technological transformation of healthcare systems to telemedicine, e-health, connected health, and remote health is being made possible with the sophisticated integration of IoMT with machine learning, big data, artificial intelligence (AI), and other technologies. As healthcare systems are becoming more accessible and advanced, security and privacy have become pivotal for the smooth integration and functioning of various systems in H-CPSs. In this work, we present a novel approach that integrates PUF with IOTA Tangle and blockchain and works by storing the PUF keys of a patient’s Body Area Network (BAN) inside blockchain to access, store, and share globally. Each patient has a network of smart wearables and a gateway to obtain the physiological sensor data securely. To facilitate communication among various stakeholders in healthcare systems, IOTA Tangle’s Masked Authentication Messaging (MAM) communication protocol has been used, which securely enables patients to communicate, share, and store data on Tangle. The MAM channel works in the restricted mode in the proposed architecture, which can be accessed using the patient’s gateway PUF key. Furthermore, the successful verification of PUF enables patients to securely send and share physiological sensor data from various wearable and implantable medical devices embedded with PUF. Finally, healthcare system entities like physicians, hospital admin networks, and remote monitoring systems can securely establish communication with patients using MAM and retrieve the patient’s BAN PUF keys from the blockchain securely. Our experimental analysis shows that the proposed approach successfully integrates three security primitives, PUF, blockchain, and Tangle, providing decentralized access control and security in H-CPS with minimal energy requirements, data storage, and response time. 

Abstract Here, the radiation hardness of metal halide perovskite solar cells exposed to space conditions versus the effects of environmental degradation are assessed. The relative response of the constituent layers of the architecture to radiation is analyzed, revealing a general resilience of the structure when assessed across varying proton energy levels and fluences. However, despite the tolerance of the structure to irradiation, sensitivity to environmental degradation is observed during the transit of the device between the radiation and characterization facilities. Experimental evidence suggests the NiO_x/perovskite interface is particularly sensitive to the effects of humidity and/or temperature exposure, while the irradiation of the devices appears to induce thermally activated annealing: improving the solar cells upon radiation exposure. 

The rapid adoption of Internet-of-Medical-Things (IoMT) has revolutionized e-health systems, particularly in remote patient monitoring. With the growing adoption of Internet-of-Medical-Things (IoMT) in delivering technologically advanced health services, the security of Medtronic devices is pivotal as the security and privacy of data from these devices are directly related to patient safety. PUF has been the most widely adopted hardware security primitive which has been successfully integrated with various Internet-of-Things (IoT) based applications, particularly in smart healthcare for facilitating device security. To facilitate security and access control to IoMT devices, this work proposes a novel cybersecurity solution using PUF for facilitating global access to IoMT devices. The proposed framework presents an approach that enables the patient’s body area network devices supported by PUF to be securely accessible and controllable globally. The proposed cybersecurity solution has been experimentally validated using state-of-the-art SRAM PUF, a delay based PUF, and a trusted platform module (TPM) primitive.