Portable Detector Research Articles

Greenhouse gas levels (CH4 and CO2) in Lagos state and Oyo state, Nigeria

The proliferation of greenhouse gases has emerged as a grave menace to humanity. According to scientists, the concentration of these gases, particularly carbon dioxide and methane, is directly linked to the rapid pace of global warming and climate change. To investigate this matter, a study was conducted utilizing a portable gas detector to measure the levels of carbon dioxide and methane in four locations each in Ibadan and Lagos for three months. Readings were collected at each sampling site three times, with each collection period lasting 5 to 15 min. These readings were taken at intervals of 2 to 3 h over a period of 3 months, while also exploring their correlation with meteorological parameters (Temperature, wind speed and relative humidity). Farms, airports, residential areas, and dump sites were deliberately selected due to their contribution to greenhouse gas emissions. The study yielded the following mean concentrations of CO2 in Lagos: 717.67 ppm in Residential Areas, 751.78 ppm in Farmland, 743.78 ppm at the Airport, and 732.56 ppm at the Dumpsite. Similarly, the mean concentrations of CH4 were 0.14 ppm, 0.30 ppm, 0.36 ppm, and 0.45 ppm, respectively. In Ibadan, the average CO2 concentrations were 676.44 ppm in residential areas, 765.11 ppm in farms, 653.33 ppm at the airport, and 683.67 ppm at the dump site. The average CH4 concentrations were 0.08 ppm, 0.32 ppm, 0.43 ppm, and 0.30 ppm, respectively. Furthermore, significant relationships between CO2 and CH4 with meteorological parameters were observed, with R2 values of 0.200 for CO2 in Ibadan, 0.08 for CO2 in Lagos, 0.56 for CH4 in Ibadan, and 0.35 for CH4 in Lagos. Cities, farms, airports, and landfills are responsible for substantial greenhouse gas emissions. The massive release of CO2 and CH4 has resulted in profound impacts and consequences that fuel climate change. This research provides valuable insights into the issue, consequences, and mitigation strategies pertaining to the reduction and regulation of CO2 and CH4 emissions in Lagos and Ibadan, Nigeria.

Detection and Analysis of Chili Pepper Root Rot by Hyperspectral Imaging Technology

The objective is to develop a portable device capable of promptly identifying root rot in the field. This study employs hyperspectral imaging technology to detect root rot by analyzing spectral variations in chili pepper leaves during times of health, incubation, and disease under the stress of root rot. Two types of chili pepper seeds (Manshanhong and Shanjiao No. 4) were cultured until they had grown two to three pairs of true leaves. Subsequently, robust young plants were infected with Fusarium root rot fungi by the root-irrigation technique. The effective wavelength for discriminating between distinct stages was determined using the successive projections algorithm (SPA) after capturing hyperspectral images. The optimal index related to root rot between each normalized difference spectral index (NDSI) was obtained using the Pearson correlation coefficient. The early detection of root rot illness can be modeled using spectral information at effective wavelengths and in NDSI, together with the application of partial least squares discriminant analysis (PLS-DA), least squares support vector machine (LSSVM), and back-propagation (BP) neural network technology. The SPA-BP model demonstrates outstanding predictive capabilities compared with other models, with a classification accuracy of 92.3% for the prediction set. However, employing SPA to acquire an excessive number of efficient wave-lengths is not advantageous for immediate detection in practical field scenarios. In contrast, the NDSI (R445, R433)-BP model uses only two wavelengths of spectral information, but the prediction accuracy can reach 89.7%, which is more suitable for rapid detection of root rot. This thesis can provide theoretical support for the early detection of chili root rot and technical support for the design of a portable root rot detector.

Quantitative analysis of Δ9-tetrahydrocannabinol (Δ9-THC) in cannabis plants using the Fast Blue BB (FBBB) and 4-aminophenol (4-AP) colorimetric tests

The Fast Blue BB (FBBB) and 4-aminophenol (4-AP) colorimetric tests have been reportedly used for the qualitative determination of Δ9-THC in plants and for the differentiation between marijuana and hemp-type cannabis. We report the miniaturization of the FBBB colorimetric reaction on a silicone treated filter paper substrate and the analytical figures of merit for a quantitative determination of Δ9-THC for the first time. The reaction between Δ9-THC and FBBB forms a red chromophore that fluoresces when irradiated with visible (480 nm) or UV (365 nm) light, providing a 3-fold increase in sensitivity. Portable instruments are introduced for the objective color determination for both tests and for the fluorescence reading of the THC + FBBB complex. We report a fluorescence signal with Δ9-THC, Δ8-THC, and CBN. The limit of detection (LOD) was determined to be 1.6 ng/μL with precision ∼12 % RSD for standard Δ9-THC solutions ranging between 5 and 20 ng/μL. The linear dynamic range for this test is reported between 1.6 ng/μL and 20 ng/μL for the portable fluorescence detector. The miniaturization of both colorimetric tests and the increased sensitivity of the FBBB test using fluorescence analysis, coupled to portable instruments allows for limited quantitative analysis of cannabis plants in the field.

Robust lanthanide MOFs as multifunctional luminescent sensors for intelligent visualization monitoring of MEAA and texture code anti-counterfeiting applications

Ln-MOFs were designed for anti-counterfeiting labels by using texture codes. Moreover, three visual probes based on 1-Eu for MEAA detection are fluorescent films, RGB intelligent detection sensor platforms, and portable logic detectors.

RAD01: Development of a NUMTEK RAD01 Low-Cost, Portable Digital Gamma Radiation Detector

Additive manufacturing and open-source affordable instruction provide equal opportunities. Therefore, it is possible to quickly, compactly, and cheaply make expensive, scarce, and large devices in the previous century. The Geiger-Muller tube is used for the primary sensing component proposed and incorporates digital signal processing to ensure accurate and reliable measurement of gamma radiation. The performance of the developed detector is evaluated through experimental testing and comparisons with commercially available radiation detection devices. The results demonstrate the detector's ability to provide precise and consistent measurements while remaining cost-effective. Moreover, its portability and user-friendly interface make it suitable for various applications, including environmental monitoring, nuclear safety, personal radiation exposure assessment, and, most importantly, educational purposes. This low-cost portable digital gamma radiation detector contributes to the field of radiation detection by presenting an accessible solution that addresses the financial limitations associated with conventional gamma radiation detectors.

Portable glucose detector based on nickel oxide modified Screen Printed Carbon Electrode (SPCE)

A portable and low-cost system prototype for glucose detector based on LMP91000EV M potentiostat has been created. Characterization of Screen-Printed Carbon Electrodes (SPCE) without modification (bare SPCE) and modified nickel oxide (NiO/SPCE) was carried out with a commercial potentiostat to see the effect of nickel oxide in detecting glucose. Through the electrochemical impedance spectroscopy method, the Rct value of 1,276.79 Ω is obtained for NiO/SPCE and 429.06 Ω for bare SPCE, so that NiO/SPCE has a slower electron transfer rate. Meanwhile, through the cyclic voltammetry method, the surface-active electrode area is 7.1×10-2cm2 for NiO/SPCE and 6.9×10-2 cm2 for bare SPCE, so that NiO/SPCE is more sensitive in detecting glucose. When the glucose concentration is varied, the Limit of Detection (LOD) and Limit of Quantitation (LOQ) values of NiO/SPCE are smaller, specifically 1.807 mM and 6.024 mM than bare SPCE, specifically 2.629 mM and 8.762 mM, so NiO/SPCE is more sensitive. When the scan rate is varied, the gradient value of NiO/SPCE is smaller, specifically -8.14×10-4 mA s/mV than bare SPCE, specifically -9.62×10-4 mA s/mV, so NiO/SPCE is not more sensitive. Next, comparing a prototype system that Trans Impedance Amplifier (TIA) gain is varied and a commercial potentiostat. As a result, the cyclic voltammogram per cycle on commercial potentiostat is more stable. The smaller the TIA gain on the system prototype, the more stable it is, this is because the noise that is amplified is getting smaller.

Bioluminescence assay for rapid detection of live Staphylococcus aureus based on the enrichment of egg yolk antibody modified magnetic metal organic framework immunobeads.

Specific and rapid detection of live Staphylococcus aureus (S.A) in environmental and food samples is critically important for protecting human health. In order to fulfill this purpose, two kinds of novel egg yolk antibody (IgY) immobilized immunomagnetic beads (IMBs; mSiO2-IgY and mMOF-IgY), with core-shell mSiO2 and mMOF as substrate, were prepared for selectively enriching S.A from samples. Furthermore, the IMBs with captured S.A were collected and re-dissolved in 0.5 mL PBS. After that, a cotton swab coated with sodium dodecylsulfate (SDS) was put in the solution to lyse S.A cells and emit ATP bioluminescence of the luciferin/luciferase system. Finally, a portable bioluminescence detector was used for quantification of ATP corresponding to S.A concentration. The results demonstrated that mMOF-IgY can enrich more S.A than mSiO2-IgY and emit a stronger signal. The reasons may be due to the higher immobilization amount of IgY on the IMBs. Under optimal conditions, the calibration line of S.A concentration was 10-105 CFU mL-1 by mMOF-IgY within 30 min. The low detection limit of S.A was 3 CFU mL-1. The results demonstrated that the assay takes much shorter time than plate counting. Its portability and excellent detection capability are suitable for rapid monitoring of specific pathogens in foods.

Exhaust Emission Assessment of Haulage Trucks at Onne Port, Nigeria

Haulage trucks are among the primary causes of air pollution in urban areas. The effect of air pollution caused by transportation, especially freight transportation, on public health is a major concern globally. In this study, emissions of haulage trucks operating at Onne Port, Rivers State in Nigeria were assessed to understand their contribution to local air pollution and environmental impact. Real-time measurements of air pollutants were taken using a portable Testo 350 Analyzer and a portable IGRESS Intelligent Detector from seventy (70) haulage trucks at Onne Port grouped according to production years, region of origin, and truck length, and the data obtained were compared with the World Health Organization (WHO) air quality standards. The results revealed that the trucks’ emissions exceeded WHO limits for six criteria pollutants, including NO2, SO2, CO, PM1, PM2.5, and PM10, which are associated with adverse health effects such as respiratory and cardiovascular diseases. Other notable findings included higher concentrations of NO2 at 35.48 ppm and PM2.5 at 300.73 µg/m3 from trucks produced between 2011 and 2021, while older trucks exhibited increased emissions of SO2 at 31.16 ppm, CO at 775.87 ppm, PM1 at 216.75 µg/m3, and PM10 at 341.75 µg/m3. There were no significant variations in pollutant emission concentrations observed within the four categories across different production years. Trucks manufactured in Asia consistently emitted lower pollutant concentrations compared with those from other regions, suggesting the influence of varying emission standards. Interestingly, truck length did not significantly impact emission levels. These findings underscore the urgency of addressing the air quality issues associated with haulage trucks in the region, highlighting the need for stringent emissions control measures.

Smartphone readable three dimensional printed analytical kit for on-site detection of Cr(VI)

A rapid and easy-used colorimetric method was developed for on-site and rapid analysis of Cr(VI). Under acidic condition, Cr(VI) was reacted with 1, 5-diphenylcarbazide (DPC) and a purple-red complex was formed subsequently, inducing the color changed from colorless to purple-red, this color variance can be detected by ultraviolet–visible spectrophotometer (UV–Vis), smartphone and even naked-eye. For realizing the goal of on-site analysis, this method was integrated in a three dimensional (3D) printed analytical kit, smartphone was used as a portable detector. Under the optimized conditions, limit of detections (LODs) of 0.0014 μg/mL and 0.0016 μg/mL were obtained by smartphone and UV–Vis, respectively. Concentration of Cr(VI) as low as 0.05 μg/mL was still visible by naked-eye. This colorimetric system was further applied to the analysis of several environmental water samples, recoveries of 90–107 % were obtained. It is a promising portable analytical device/system for Cr(VI) on-site and rapid analysis.

Comparison of effective doses for personnel performing flaw detection in stationary conditions and <i>in situ</i>

Official data on radiation doses for flaw detectors do not take into account working conditions. In the reporting forms, there is no division between personnel performing flaw detection in stationary conditions and in situ, which roughly averages the values of effective doses towards underestimating the values for personnel working in site radiography. In this work, comparison of our own data on radiation doses of flaw detectors was performed. It has been shown that the difference in the mean and median values of effective doses reaches 10 times. When performing flaw detection in stationary conditions, the personnel are at a sufficient distance from the source of ionizing radiation and are well shielded by engineering protective equipment, so the exposure is fairly uniform. In such cases, one individual thermoluminescent dosimeter located at chest level is sufficient to estimate the effective dose. The average annual effective dose for personnel conducting flaw detection in stationary conditions is 0.87 mSv (median – 0.88 mSv, maximum value – 0.99 mSv). During individual radiation monitoring of personnel performing flaw detection in situ using portable roentgen flaw detectors, cases of neglect in the use of individual dosimeters were identified, which requires more stringent measures to comply with existing requirements for ensuring radiation safety and operating rules for individual dosimeters. The average annual effective dose for flaw detectors working with portable roentgen flaw detectors is 9.03 mSv (median – 8.85 mSv, maximum value – 12.37 mSv).

Assessment of Environmental Background Gamma Radiation Variation in Minna Area of Nigeria

Radiation has been acknowledged to be responsible for deleterious conditions in living tissues. Hence, environmental background gamma radiation (BGR) measurement is crucial from an environmental and health perspective. In this study, due to the absence of comprehensive background gamma radiation data and the increasing numbers of anthropogenic activities that could increase the BGR level, such as where mining activities are active. The BGR in the Minna area of Niger State, Nigeria, was measured and analyzed in this study. In-situ measurement of the background gamma radiation level was carried out using a well-calibrated portable handheld GQ GMC-500 Plus nuclear radiation detector at an elevation of about 1.0 m above ground level. A global positioning system from Garmin (GPSmap 78s) was adopted for identifying geographical locations. A total of 1172 points were surveyed across the study area for background environmental radiation. The BGR values ranged from 0.102 to 0.147 μSv/h, with an overall mean value of 0.126 μSv/h. The average measured dose rate was more than twice the reported world average value of 0.059 μSv/h. The annual effective dose equivalent (AEDE) for the research area was calculated to be 0.221 mSv/y on average. The mean AEDE is lower than the ICRP recommended limit. This shows that the population of the Minna area is radiologically safe based on the estimated AEDE value. Similarly, the excess lifetime cancer risk (ELCR) value ranged from 0.626 × 10−3 to 0.901 × 10−3 mSv/y with a mean value of 0.774 ± 0.09 × 10−3 mSv/y. The mean value of AEDE is below the 0.24 mSv/y permissible limits as recommended by the International Commission on Radiological Protection (ICRP). The mean ELCR value exceeds the average world value of 0.29 × 10−3. Also, the mean organ dose values estimated for the whole body, liver, kidney, testes, bone marrow, ovaries, and lungs are 0.150 ± 0.02, 0.102 ± 0.01, 0.137 ± 0.02, 0.181 ± 0.02, 0.152 ± 0.02, 0.128 ± 0.02 and 0.141 ± 0.02 mSv/y respectively. The differences in the calculated mean of BGR were attributed to natural and human factors. Geological variation is a fundamental factor that influences the changes in BGR. Human activities, mining, building materials, and the use of phosphate fertilizers in agricultural practices are responsible for the differences in BGR. The ELCR implies that terrestrial gamma radiation does not pose any immediate radiological health effects on residents of the area, but there is a tendency for long-term health hazards in the future, such as cancer, due to the dose accumulated.

Picomolar-Level Sensing of Cannabidiol by Metal Nanoparticles Functionalized with Chemically Induced Dimerization Binders.

Simple and fast detection of small molecules is critical for health and environmental monitoring. Methods for chemical detection often use mass spectrometers or enzymes; the former relies on expensive equipment, and the latter is limited to those that can act as enzyme substrates. Affinity reagents like antibodies can target a variety of small-molecule analytes, but the detection requires the successful design of chemically conjugated targets or analogs for competitive binding assays. Here, we developed a generalizable method for the highly sensitive and specific in-solution detection of small molecules, using cannabidiol (CBD) as an example. Our sensing platform uses gold nanoparticles (AuNPs) functionalized with a pair of chemically induced dimerization (CID) nanobody binders (nanobinders), where CID triggers AuNP aggregation and sedimentation in the presence of CBD. Despite moderate binding affinities of the two nanobinders to CBD (equilibrium dissociation constants KD of ∼6 and ∼56 μM), a scheme consisting of CBD-AuNP preanalytical incubation, centrifugation, and electronic detection (ICED) was devised to demonstrate a high sensitivity (limit of detection of ∼100 picomolar) in urine and saliva, a relatively short sensing time (∼2 h), a large dynamic range (5 logs), and a sufficiently high specificity to differentiate CBD from its analog, tetrahydrocannabinol. The high sensing performance was achieved with the multivalency of AuNP sensing, the ICED scheme that increases analyte concentrations in a small assay volume, and a portable electronic detector. This sensing system is readily applicable for wide molecular diagnostic applications.

A solid-phase fluorescence sensor for measuring chemical species in water

In this study, the first of its kind, a solid-phase fluorescence sensing platform was developed to quantify contaminants in water. ZnO quantum dots (QDs) were combined with molecularly imprinted polymers (MIPs) to form fluorescence sensing materials. Solid sensing layers were formed via a straightforward spin-coating method, which demonstrated a strong attachment to the sensor substrate while maintaining the integrity of the sensing materials. The developed sensing platform comprised a portable fluorescence detector to measure fluorescence intensity, instead of traditional fluorescence spectroscopy. The solid sensing platform was first tested with 2,4-dichlorophenoxyacetic acid (2,4-D), demonstrating high sensitivity (0.0233) and a very strong correlation (0.98) between the target molecule concentration and sensor signal. Further, the sensing platform was successfully adapted to measure a substance with a different molecular mass and chemical structure, the algae toxin microcystin-LR (MCLR); this demonstrated the sensor's versatility in quantifying target molecules. Tap water samples spiked with MCLR were also used to test the sensor's practical application. Finally, the working mechanism of the sensing platform was established, and the key information for using the sensor to measure various contaminants was determined. With its high performance, broad applicability, and ease of use, the developed platform provides a suitable basis for lab-on-chip image-based sensing devices for environmental monitoring.

Compact RF transmission unit for nuclear quadrupole resonance spectroscopy

Nuclear quadrupole resonance (NQR) spectroscopy is a non-destructive measurement technique that enables to detect materials of interest very accurately. This technique works by sending high power electromagnetic waves with radio frequency (RF) very specific to the molecular structure to excite the sample and detecting the respond signal with the same frequency. Portable NQR detectors can be potentially developed to detect explosives with non-metallic containers in the fields. However, commercial RF high power amplifiers are large and heavy, so they are not practical for field usage. In this work, we demonstrate a compact NQR transmission part which composed of an active input signal conditioner, a class-D amplifier, and an NQR coil. The active input signal conditioner circuit will convert a single rf pulse with low amplitude (<0.5Vp) to two pulses (with 180° phase difference) and they are subsequently amplified to TTL level. In the class-D amplifier, the pre-amplified pulses are further amplified by a high voltage gate driver IC to 24V amplitude. These high voltage pulses are converted to a single 24V pulse by MOSFETs connected in a half bridge configuration. Finally, the amplified pulse is fed to the NQR coil, i.e., a low impedance LC series resonance circuit. The voltage across the coil at resonance frequency is about 1kVpp.

Investigating the possibility of leakage detection in water distribution networks using cosmic ray neutrons in the thermal region

Water distribution systems can experience high levels of leakage, originating from different sources, such as deterioration due to aging of pipes and fittings, material defects, and corrosion. In addition to causing financial losses and supply problems, leakages in treated water distribution also represent a risk for public health. Despite several techniques for leak detection are already available, there is still a lot of interest in new non-invasive approaches, especially for scenarios where acoustic techniques struggle, such as in noisy environmental conditions.In this work we investigated the possibility of using cosmic ray (CR) neutrons for the detection of underground leakages in water distribution networks, by exploiting the difference in the above ground thermal neutron flux between dry and wet soil conditions. The potential of the technique has been assessed by means of an extensive set of Monte Carlo simulations based on GEANT4, involving realistic scenarios based on the Italian aqueduct design guidelines. Simulation studies focused on sandy soils and results suggest that a significative signal, associated with a leakage, could be detected with a data-taking lasting from a few minutes to a half-hour, depending on the environmental soil moisture, the leaking water distribution in soil, and the soil chemical composition.Finally, a brief description of a new portable and low-cost detector for thermal neutrons, currently under commission, is also presented.

Application of Portable CH4 Detector Based on TDLAS Technology in Natural Gas Purification Plant

Methane (CH4) is the main pollutant in oil and gas production. The detection and accounting of CH4 is an important issue in the process of greenhouse gas control and emission reduction in oil and gas industry. In this study, a portable CH4 detector based on tunable diode laser absorption spectroscopy (TDLAS) technology was deployed. The three-dimensional distribution of CH4 in a natural gas purification plant in Sichuan was obtained through vertical unmanned aerial vehicle (UAV) flight observations and ground mobile observations. According to the mass balance method, the emission of CH4 on 30 m above ground level (AGL) and 60 m AGL in this site was about 0.012 kg/s (±42% at 1σ) and 0.034 kg/s (±47% at 1σ), respectively, in one day. The vertical distribution showed that the CH4 concentration reached the maximum (2.75 ± 0.19 ppm) with height of 0 to 100 m AGL. The CH4 concentration from 100 to 300 m AGL showed a downward trend with height. Atmospheric instability at high altitude and high wind speed promoted the diffusion of CH4. The CH4 concentrations of horizontal distribution on 30 m AGL and 60 m AGL were 2.48 ± 0.11 ppm and 2.76 ± 0.34 ppm. In the observation of mobile campaigns, the connecting equipment of natural gas treatment facilities was prone to leakage, such as in valves and flanges. CH4 leakage was also detected at the torch mouth, especially when there was an open flame at the torch mouth. During the mobile movement investigation, the downwind measurement (OTM-33A) was applied to determine the overall CH4 emission rate shortly after patrolling the site. This work plays a vital role in optimizing the operation and maintenance of natural gas production stations pipe network, ensuring human safety and minimizing greenhouse gas emissions.

Synthesis of Novel Fluorescent Conjugated Polymers and Their Rapid Gas‐Phase Detection of Trace Nitro‐Explosives

AbstractFluorescent conjugated polymers are widely investigated for their excellent performance in detecting explosives. In this work, two simple monomers are used to synthesize two novel fluorescent conjugated polymers, 3 and 6, with different conjugated structures via the linkages of “single bond” and “alkyne bond” by coupling reaction, and the fluorescence sensing performance for 2,4,6‐trinitrotoluene (TNT) is verified in both liquid and gas phases, aiming to demonstrate the influence of two different linkages on the fluorescence sensing properties. The fluorescent intensities of conjugated polymers in organic solvents gradually increase with increasing concentration within the low concentration range, while too high concentration leads to a decrease in the emission intensity because of the concentration quenching effect. The liquid‐phase limit of detection of 3 and 6 for TNT is as low as 1.9 and 1.6 µm in acetonitrile, respectively. The change rule of UV–vis absorption indicates that the static quenching model of TNT is predominant in liquid phase. Using a commercial portable explosives detector, 3 and 6 can effectively achieve the selective detection of gas‐phase TNT above 15 ng within 7 s and 8 ng within 5 s, respectively, demonstrating the great potential for rapid on‐site detection of trace explosives.

Women Safety Portable Hidden Camera Detector

The women's safety portable hidden camera detector is a small, easy-to-use tool that helps people—women in particular—protect their security and privacy. The gadget uses cutting-edge camera detection technologies, such as infrared and RF signal recognition, to locate hidden cameras in a variety of settings. When a hidden camera is found, the detector notifies users through both visual and auditory alerts, all while maintaining a discrete and portable design. Furthermore, this innovative device empowers individuals to reclaim their sense of security, making it an invaluable tool for personal privacy in an increasingly interconnected world. Its discreet and portable design ensures that users can carry it with ease, offering peace of mind wherever they go. With the women's safety portable hidden camera detector, one can step confidently into any environment, knowing they have a reliable shield against potential privacy breaches and safeguard their personal space.

Spatial distribution of radon concentration and risk evaluation through consumption of groundwater in the District of Kotli, Azad Jammu and Kashmir

Radon (222Rn) is naturally readily water-soluble, posing a cancer risk to the exposed community. Human exposure in the community may occur via 222Rn intake in drinking water. Groundwater is used for drinking and other domestic purposes in the region. Higher concentrations of 222Rn in groundwater have been reported near Kotli district, Azad Jammu, and Kashmir. This investigation aimed to measure 222Rn concentrations in groundwater and evaluate the associated risk assessment for children and adults in the Kotli district. 222Rn concentrations were measured in randomly collected groundwater samples of Kotli (n = 25) and Sehnsa (n = 15) towns in the Kotli district using the portable Radon Detector (RAD7, Durridge Company, United States of America). Among the studied areas, the Sehnsa showed a higher average 222Rn concentration (7.6 ± 0.2 Bq/L) in groundwater compared to Kotli (6.0 ± 1.9 Bq/L). The average concentrations of 222Rn were found within the recommended limit (11.1 Bq/L) of the United States Environmental Protection Agency (USEPA), except for 10% of sampling sites. 222Rn concentrations were used for the calculation of total effective dose for ingestion and inhalation pathways (EwTotal) values for infants (24.5 ± 7.5 and 30.7 ± 0.9 μSv/a), children (18.1 ± 5.5 and 23.5 ± 0.7 μSv/a), and adults (18.1 ± 5.5 and 22.7 ± 0.3 μSv/a) in the Kotli and Sehnsa, respectively. This study noted that EwTotal and estimated lifetime cancer risk (ELCR) values were found within the World Health Organization (WHO) and European Commission (EU) acceptable limits (<100 μ Sv/a and 0.1 × 10−3).

PortableSingle-Exposure Dual-Energy X-ray Detector for Improved Point-of-Care Diagnostic Imaging.

Dual-energy subtraction (DES) imaging is well known to reduce anatomical noise and enable material classification. The current approaches to DES imaging have trade-offs, such as motion artifacts, low sensitivity because of losses in a mid-filter, and lack of portability. Recently, a portable triple-layer flat-panel detector (FPD) was proposed for use in single-shot DES imaging that can provide improved sensitivity and removal of motion artifacts in a point-of-care setting. The purpose of this study is to evaluate the feasibility of such a detector. Various image quality metrics and clinical images are provided. An FDA-cleared single-exposure DES FPD consisting of three stacked sensors was used for all measurements. This detector generates three images per exposure: A digital radiography (DR) image, i.e., as would be produced with a conventional detector, and two DES images, bone and soft tissue. To evaluate DR image quality, detective quantum efficiency (DQE) and modulation transfer function were measured for multiple radiation quality beams. Digital radiography and DES images obtained from this FPD were evaluated in previously reported fixed and portable clinical studies. Digital radiography and DES images from case studies are presented for qualitative assessment. Modulation transfer function and DQE were measured across multiple radiation quality beams for the DR image. The DES images showed good tissue separation and uniformity with no visible motion or alignment artifacts. The DES images, when read in conjunction with the DR image, resulted in increased reader confidence and revealed abnormalities or details that were sometimes overlooked in the DR image. The proposed panel produces high-quality DR images as indicated by the DQE and modulation transfer function. The DES images have been shown to improve sensitivity in clinical applications and increase reader confidence. This detector can enable DES in portable or otherwise difficult applications, opening new doors for improved patient care.