Specific Detector Research Articles

Aggregation-Induced Emission Molecule Microwire-Based Specific Organic Vapor Detector through Structural Modification.

An optical organic vapor sensor array based on colorimetric or fluorescence changes quantified by spectroscopy provides an efficient method for realizing rapid identification and detection of organic vapor, but improving the sensitivity of the optical organic vapor sensor is challenging. Here, AIE/polymer (AIE, ggregation-induced emission) composites into microwires arrays are fabricated as organic vapor sensors with specific recognition and high sensitivity for different vapors using the capillary-bridge-mediated assembly method. Such organic vapor sensor successfully detects organic vapor relying on a swelling-induced fluorescence change of the AIE/polymer composites, combating the unique property of AIE molecules and vapor absorption-induced polymer swelling. A series of AIE/polymer composites into microwires arrays with four different groups on the AIE molecule and four different side chains on the polymer is fabricated to detect four different organic vapors. The mechanism for improved sensitivity of the AIE/polymer composites microwires arrays sensors is the same because of the similar polarity between the group of AIE molecules and the vapor molecules. Molecular design of the side chains of the polymer and the groups of AIE molecules based on the polarity of the targeted vapor molecule can enhance the sensitivity of the sensors to the subparts per million level.

Generating a Hand Pose Data Set for Vision Based Manual Assembly Assistance Systems

Current assistance systems for manual assembly reduce the efficiency of the worker by being invasive in the workflow. To restore the efficiency and at the same time to maintain the benefits of assistance systems, real time hand pose estimation can be used. However, no suitable data set is available for training such application specific detectors. In the presented work, a data set is generated that allows the use of different work gloves and prepares the overlay of realistic hand textures. We use low cost data gloves for hand pose tracking and a RGBD camera to capture the data set with 30 data points per second. This low cost approach is presented in an application for the manual assembly scenario, although transfer of the method to other scenarios is possible.

Improving Object Detection Quality by Incorporating Global Contexts via Self-Attention

Fully convolutional structures provide feature maps acquiring local contexts of an image by only stacking numerous convolutional layers. These structures are known to be effective in modern state-of-the-art object detectors such as Faster R-CNN and SSD to find objects from local contexts. However, the quality of object detectors can be further improved by incorporating global contexts when some ambiguous objects should be identified by surrounding objects or background. In this paper, we introduce a self-attention module for object detectors to incorporate global contexts. More specifically, our self-attention module allows the feature extractor to compute feature maps with global contexts by the self-attention mechanism. Our self-attention module computes relationships among all elements in the feature maps, and then blends the feature maps considering the computed relationships. Therefore, this module can capture long-range relationships among objects or backgrounds, which is difficult for fully convolutional structures. Furthermore, our proposed module is not limited to any specific object detectors, and it can be applied to any CNN-based model for any computer vision task. In the experimental results on the object detection task, our method shows remarkable gains in average precision (AP) compared to popular models that have fully convolutional structures. In particular, compared to Faster R-CNN with the ResNet-50 backbone, our module applied to the same backbone achieved +4.0 AP gains without the bells and whistles. In image semantic segmentation and panoptic segmentation tasks, our module improved the performance in all metrics used for each task.

Universal firefighter sensor for dangerous road tunnel environment

This article deals with the issue of detecting and measuring the concentration of dangerous substances in the road tunnel during an accident, in order to minimize the risk to the firefighter during the intervention. The article also includes the design and construction of a mobile sensor system together with the processing of data and a suitable presentation of measured data. The gases are measured by specific detectors of the MQ gas sensors series. NTC type thermistors were used for temperature measuring. The control unit for the mentioned universal sensor is the development board D1 mini Pro, which has an integrated Wi-Fi chip. The universal sensor was designed especially for firefighters intervening during an accident in road tunnels. The measured data are processed and then sent via Wi-Fi network to an external database, from which they are then conveniently presented on the website. The website is then viewed on-line data from sensor for firefighters, whose are intervening during an accident in the tunnel.

Universal Sensor for Use in Dangerous Road Tunnel

This article deals with the problems of detection of dangerous substances in the road tunnel during an accident and proposes-design and construction of a mobile sensor system for online detection. Gases are measured by specific detectors of the MQ series. The D1 mini Pro development board with WiFi chip integration was chosen as the control unit. The universal sensor was designed especially for firefighters intervening during an accident in road tunnels. The measured data are sent and saved into the external database, from which they are then presented on the website. The website is then viewed on-line firefighters who intervene in the tunnel during an accident.

Electrochemical Detection of Neurotransmitters in the Brain and Other Molecules with Biological Activity in the Nervous System: Dopamine Analysis

Monitoring the appropriate functions of the brain is a priority when the diagnosis of neurological diseases is carried out. In this regard, there are different analytical techniques to detect neurotransmitters and other molecules with biological activity in the nervous system. Among several analytical procedures, electrochemical techniques are very important since they can be applied in situ, without loss of sensibility and/or minimal handling of samples. In addition, it is also possible to combine them with specific detectors designed on the basis of chemically-modified electrodes in order to improve detection limits by promoting molecular recognition capabilities at their surfaces, thus favoring the development of electrochemical detection in vivo by microelectrodes. In this mini-review, we will describe the major characteristics of this analytical method and its advantages for the detection of neurotransmitters (mostly dopamine) in vivo.

Evaluation And Selection Of Colour Spaces For Digital Systems

The research examined the changing of colour difference by the control colours depending on the choice of colour space when working with matrix photo detector. The spectral characteristics of photo detectors from different manufacturers noticeably differ from each other and from the addition the difference in colour quality between different digital devices. A software method for studying the colour rendition of the image obtained by digital devices based on the selection of an individual colour space for each matrix photo detector is proposed. To analyze and evaluate the capabilities of the spectral characteristics of matrix photo detectors, the control colour method based on the Mansell Atlas was used. The analysis of the obtained parameters of 14 colours was carried out according to various criteria for seven colour spaces: sRGB, AdobeRGB, DCI-P3 RGB, M1N1P1, PAL / SECAM, Wide Gamut RGB, ProPhoto RGB. Also studied the influence of the choice of colour space on the change in the coordinates of the source 6,500 K. Based on the colour differences of the control colours, it is possible to choose the optimal colour space for working with a specific matrix photo detector. The latter will reduce colour distortion at the initial stage of image registration. The ways for improving the colorimetric method of control colours are proposed as applied to digital devices at the software level.

Ultrasound assisted oxidative desulfurization of marine fuels on MoO3/Al2O3 catalyst

Oxidative desulfurization (ODS) was applied to three marine fuels with viscosities between 380 and 700 cSt (centistokes) and sulfur contents between 0.79 and 3.27 wt.%, using a MoO3/Al2O3 catalyst. H2O2 was chosen as oxidizing agent with a low oxidant to sulfur ratio of 3, for economic and environmental reasons. Global sulfur removal was obtained after extraction of sulfones by dimethylformamide. Oxidation efficiency was evaluated by monitoring the conversion of alkyl-benzothiophenes and dibenzothiophene molecule by gas chromatography (GC) with a sulfur specific detector. Applying ultrasounds prior to oxidation was found to significantly enhance conversions and sulfur removal, the effect being more pronounced when initial efficiency was low, that is for more refractory molecules and heavier fuels. Ultrasound assisted ODS (UAOD) was effective on raw fuels with initial viscosity below 700 cSt. Indeed, dilution decreased the viscosity of the fuels, allowing reaction to be effective even on initially very heavy fuels. The presence of asphaltenes dissolved or precipitated in the feed did not affect the conversion of Cx-BTs and DBT significantly, with only slight variations of global sulfur removal rates. Global desulfurization rates between 60 and 80 % were obtained, clearly showing the efficiency of UAOD applied to complex matrices such as marine fuels.

Gas R&D on gas recirculation and recuperation for the Resistive Plate Chamber detectors

Resistive Plate Chamber (RPC) detectors at the Large Hadron Collider (LHC) experiments are operated with a gas mixture containing C2H2F4 (R134a) and SF6. These gases are used because they allow to achieve specific detector performance. However, due to their high Global Warming Potential (GWP) they are currently subject to a phase down policy that started to affect the market with price increase and it may cause a decrease in their long-term availability. To minimize these risks, four different strategies have been identified for optimizing their usage. As immediate actions and where possible, during the LHC Long Shutdown 2 (LS2) the RPC gas systems will be upgraded to cope with new detector requirements and, in parallel, extensive campaigns for fixing leaks at detector level will be performed. Since R134a dominates the greenhouse gas consumption, the development of a R134a gas recuperation plant is going to be the next step and it might have an important positive impact on the overall optimization process. Recently a prototype system was tested with encouraging results. For future long-term detector operation, R&D studies are ongoing for finding “green” alternatives to the currently used gases. Unfortunately, new gases developed by industry as refrigerant fluids are not behaving as the R134a in particle detectors which makes the replacement for present experiments difficult. The last strategy consists in the possibility of using industrial plants for the disposal of greenhouse gases by decomposition in harmless compounds. This solution avoids the emission in the atmosphere but it does not optimize the gas usage and problems like gas availability and price for detector operation might become the challenge in the coming years due to the greenhouse phase down policy.

Explanation of Photon Navigation in the Mach-Zehnder Interferometer

Photons in interferometers manifest the functional ability to simultaneously navigate both paths through the device, but eventually appear at only one outlet. How this relates to the physical behaviour of the particle is still ambiguous, even though mathematical representation of the problem is adequate. This paper applies a non-local hidden-variable (NLHV) solution, in the form of the Cordus theory, to explain photon path dilemmas in the Mach–Zehnder (MZ) interferometer. The findings suggest that the partial mirrors direct the two reactive ends of the Cordus photon structures to different legs of the apparatus, depending on the energisation state of the photon. Explanations are provided for a single photon in the interferometer in the default, open-path, and sample modes. The apparent intelligence in the system is not because the photon knows which path to take, but rather because the MZ interferometer is a finely-tuned photon-sorting device that auto-corrects for randomness in the frequency phase to direct the photon to a specific detector. The principles also explain other tunnelling phenomena involving barriers. Thus, navigation dilemmas in the MZ interferometer may be explained in terms of physical realism after all.

Establishing the Association between Blood Levels of Chloroform in Children and Concentrations of Chloroform and Its Derivatives in Drinking Water of Centralized Water Supply Systems

Background: Surface reservoirs remain one of the priority sources of drinking water in the Russian Federation whereas the increasing anthropogenic effect on the environment does not exclude the possibility of contamination of surface waters with toxic compounds. The use of traditional methods of water disinfection with active chlorine aggravates the situation and leads to formation of highly toxic organochlorine compounds. In this regard, one of the urgent hygienic problems is to establish health effect of these toxicants in the population including its most sensitive groups. The objective of the study was to establish and quantify the relationship between concentrations of chloroform and its derivatives in drinking water and blood levels of organochlorine compounds in children consuming potable water with a higher content of chlorine and its derivatives. Materials and methods: The study was conducted on six territories of the Perm Region constituting an observation area where drinking water was noncompliant with hygienic standards by a number of indices, and a comparison area. The analysis of trihalomethanes in drinking water samples was carried out in accordance with the requirements of sanitary regulations SanPiN 2.1.4.1074–01. The levels of trihalomethanes (chloroform, carbon tetrachloride, dibromochloromethane, dichlorobromethane, and 1,2-dichloroethane) in children’s blood samples were analyzed by capillary gas chromatography in combination with a specific detector to increase selectivity and sensitivity of determination. We used a Kristall-5000 gas chromatograph with an Optima-5 capillary column (25 m × 0.32 mm × 0.5 μL) and a selective electron capture detector (ECD). Results: The data of comprehensive chemical analyses of average levels of trihalomethanes in blood samples of children consuming drinking water with an increased content of determined compounds (up to 3.5 MPC) and the water complying with hygienic standards are presented. We observed significant differences (р<0.005) between two groups in the blood levels of chloroform, carbon tetrachloride, and 1,2-dichloroethane that were 5.6, 6 and 24 times higher in children of the test group compared to the controls. Conclusion: We revealed a statistically significant causal relationship between the increase in chloroform concentrations in drinking water and the increase in blood levels of chloroform in children described by the equation у=0.00188+0.01782х (R2=0.263, p=0.0018).

LGAD designs for Future Particle Trackers

Several future high-energy physics facilities are currently being planned. The proposed projects include high energy e+e− circular and linear colliders, hadron colliders, and muon colliders, while the Electron–Ion Collider (EIC) is expected to construct at the Brookhaven National Laboratory in the future. Each proposal has its advantages and disadvantages in terms of readiness, cost, schedule, and physics reach, and each proposal requires the design and production of specific new detectors. This paper first presents the performances necessary for future silicon tracking systems at the various new facilities. Then it illustrates a few possibilities for the realization of such silicon trackers. The challenges posed by the future facilities require a new family of silicon detectors, where features such as impact ionization, radiation damage saturation, charge sharing, and analog read-out are exploited to meet these new demands.

Soot formation in laminar flames of ethylene/ammonia

Co-firing NH3 with other fuels is receiving growing interest as a feasible solution to improve its combustion and emission properties. Previous studies mainly focused on NOx emission, and paid less attention to soot formation which is investigated here using a laminar counterflow flame configuration with ethylene fuel (75% by mole) mixed with different proportions of ammonia (between 0 and 25% by mole while the remainder is nitrogen). Soot volume fraction (SVF) was measured using planar laser induced incandescence (PLII). It was found that the addition of ammonia significantly reduced the measured SVF by 4–6% per 1% ammonia addition as compared to the reference flame (25% nitrogen). To rule out temperature effects, the experiments were simulated using Chemkin Pro and it was found that there were negligible differences in temperature between each condition implying that temperature was not responsible for the reduction in SVF. To investigate the chemical effects of ammonia addition, polycyclic aromatic hydrocarbons (PAH) were measured using planar laser induced fluorescence (PLIF) at 4 wavelengths (350 nm, 400 nm, 450 nm, and 500 nm). PLIF intensities at 350 nm is deemed to correlate with PAHs of 2–3 rings and measured profiles at this wavelength were nearly overlapping for all cases. These findings were supported by GC–MS measurements of acetylene and benzene with the latter showing little change in the peak for the cases studied here. At longer wavelengths, PLIF intensities began to show the same trends found for SVF measurements. Additionally, a specific nitrogen detector was used during GC–MS measurements and several nitrogen containing hydrocarbon species were detected with the 25% addition of ammonia. The combined results indicate that the nitrogen containing hydrocarbon species are likely to account for soot reduction, with the precise mechanism yet to be elucidated.

Application of a Novel Metallomics Tool to Probe the Fate of Metal-Based Anticancer Drugs in Blood Plasma: Potential, Challenges and Prospects.

Although metallodrugs are used to treat a variety of human disorders and exhibit a remarkable diversity of therapeutic properties, they constitute only a tiny minority of all medicinal drugs that are currently on the market. This undesirable situation must be partially attributed to our general lack of understanding the fate of metallodrugs in the extremely ligand-rich environment of the bloodstream. The challenge of gaining insight into these bioinorganic processes can be overcome by the application of 'metallomics tools', which involve the analysis of biological fluids (e.g., blood plasma) with a separation method in conjunction with multi-element specific detectors. To this end, we have developed a metallomics tool that is based on size-exclusion chromatography (SEC) hyphenated to an inductively coupled plasma atomic emission spectrometer (ICP-AES). After the successful application of SEC-ICPAES to analyze plasma for endogenous copper, iron and zinc-metalloproteins, it was subsequently applied to probe the metabolism of a variety of metal-based anticancer drugs in plasma. The versatility of this metallomics tool is exemplified by the fact that it has provided insight into the metabolism of individual Pt-based drugs, the modulation of the metabolism of cisplatin by sulfur-containing compounds, the metabolism of two metal-based drugs that contain different metals as well as a bimetallic anticancer drug, which contained two different metals. After adding pharmacologically relevant doses of metallodrugs to plasma, the temporal analysis of aliquots by SEC-ICP-AES allows to observe metal-protein adducts, metallodrug-derived degradation products and the parent metallodrug(s). This unique capability allows to obtain comprehensive insight into the fate of metal-based drugs in plasma and can be extended to in vivo studies. Thus, the application of this metallomics tool to probe the fate of novel metalcomplexes that exert the desired biological activity in plasma has the potential to advance more of these to animal/preclinical studies to fully explore the potential that metallodrugs inherently offer.

X-ray Technology to Determine Peanut Maturity1

ABSTRACT Indeterminate growth of peanut (Arachis hypogaea L.) creates indecision for best digging date for maturity and economic return. The current standard to determine peanut maturity is the Hull Scrape method. This method uses human observations to place hull scraped peanuts on a color maturity profile board. Human observations may lack precision and repeatability from individual to individual. X-ray technology has the capability of viewing peanut kernels through the hull to possibly ascertain density and maturity. The objective was to determine if x-ray could be used as a quick, non-destructive, and repeatable method to determine peanut maturity of runner, spanish, and virginia market types. Fresh dug peanut pods had 25 percent greater peanut area and gray scale values compared with hull scraped pods (runner and virginia only) and showed no difference in x-ray value between immature and fully mature peanut. Dried peanut showed a linear response of x-ray value versus peanut maturity (hull color). Virginia market type had much higher x-ray values followed by runners, then spanish. The relationship between peanut maturity and x-ray value peaked at the Orange class for runners (Georgia-06G, Georgia-13M), and Spanish (AT9899) while virginia (Georgia-11J) tended to peak at the Brown class. This research demonstrated that x-ray technology may be used to measure peanut density and possible maturity but needs further examination past Orange and Brown maturity class. Final x-ray values determined by this proprietary x-ray equipment may not be transferable due to specific x-ray power, detector precision, background color/scatter, and other electronic nuances.

Electrochemical immunoplatform to improve the reliability of breast cancer diagnosis through the simultaneous determination of RANKL and TNF in serum

This paper describes a dual immunosensor using neutravidin-functionalized magnetic microbeads (Neu-MBs) and dual screen-printed carbon electrodes (SPdCEs) for the simultaneous amperometric determination of two emerging biomarkers related to breast cancer (BC) and metastasis: Receptor Activator of Nuclear Factor-κB Ligand (RANKL) and Tumor Necrosis Factor alpha (TNF). In the implemented methodology, sandwich-type immunocomplexes, using biotinylated specific capture, detector antibodies and HRP-labeled secondary antibodies, are formed onto Neu-MBs. Electrochemical detection was performed by amperometry (−0.20 V vs. the Ag pseudo-reference) electrode using the H2O2/hydroquinone (HQ) system upon capturing the Neu-MBs modified with the sandwich immunocomplexes for each target biomarker on the corresponding working electrode (WE) of SPdCEs. The approach exhibits high sensitivity offering detection limits of 2.6 and 3.0 pg mL−1 for RANKL and TNF, respectively, using simple protocols and taking 90 min as assay time. The usefulness of the dual immunoplatform was tested by determining RANKL and TNF levels in 5 μL of human serum from healthy controls and BC patients diagnosed with different HER2 subtypes. Results showed a higher expression of both biomarkers in BC patients (38 and 17 % higher for RANKL and TNF, respectively) and were in agreement to those obtained using the ELISA methodologies for each target biomarker involving the same immunoreagents. The obtained results show the potential of this immunoplatform to improve the reliability of BC diagnosis using fast and cost-effective procedures.

Efficient enrichment of iron concentrate from iron tailings via suspension magnetization roasting and magnetic separation

Iron ore tailings are industrial solid wastes generated from mineral processing. The disposal of iron ore tailings leads to environmental threat and serious security because of their tiny particle size and large storage. In this paper, suspension magnetization roasting and magnetic separation technology were utilized to recover iron tailings. The results showed that iron concentrates with iron grade of 65.01% and recovery of 89.07% could be obtained under conditions of CO concentration 30%, roasting temperature 520 °C, roasting time 20 min, grinding particle size of roasted products with 94% mass fraction of − 38 μm and magnetic field strength 1800 Oe. The vibration sample magnetometer, X-ray diffraction, specific surface area detector, scanning electron microscope and energy-dispersive spectrometer showed that unit mass magnetic moment, specific magnetization coefficient and saturation value of magnetization intensity of magnetic concentrate were all significantly improved. Weak magnetic iron ore was selectively transformed into strong magnetic magnetite. Compared with raw ore, there was porous and cracked structure on the surface of roasted ore and magnetic concentrate, which was conducive to magnetization reaction, magnetism and phase transformation of iron ore.

A study of the process of malodor formation in sewer networks and analysis of methods for its elimination

Introduction. The co-authors analyze the process of malodor formation inside pipelines of non-pressure sewer networks (channels) and their efficient elimination using physicochemical, biological, catalytic, thermal, electric discharge, civil engineering and other methods. Materials and methods. The co-authors have analyzed literary sources, studied the most advanced malodor registration methods (broken down into malodor identification and intensity control) using specialized malodor detectors; they have also considered potential methods for malodor elimination or intensity reduction, as well as prevention of malodor formation and micro-climate preservation in sewer networks. Results. The co-authors have identified the reasons for the formation of malodors inside non-pressure pipelines of sewer networks and a number of negative factors that contribute to the formation of gases. The co-authors offer an overview of methods and technologies preventing the formation of anaerobic conditions inside sewer networks. They describe the cases of several cities where malodors were emitted inside sewer networks, as well as the actions aimed at their suppression in particular environments. The co-authors present specific malodor prevention actions using various methods applied in some countries of the world. Conclusions. The practical implementation of a number of actions aimed at the elimination of malodors in sewer networks is a costly project in terms of capex and operating expenses. Mobile, efficient and economically expedient methods of eliminating specific sources of malodors have been identified. The right choice of actions, technologies, design and device-focused solutions (equipment choice) need a detailed examination in terms of malodor emissions and pipeline systems as a whole, as well as consistent exploratory, research and development efforts.

Characterization of a newly developed readout electronics system for strip detectors

The aim of the present paper was to investigate the performance of a newly developed general purpose strip detector system, and its energy resolution improvement provided by custom characterization and calibration procedures described in this paper. The system contains one 128-channel silicon strip detector, four 32-channel Front-End ASICs (FE-ASICs), FPGA-based control circuit, and signal conditioning and power regulation modules, providing energy measurements up to 3.2 MeV per channel. Additionally, a dedicated software tool was developed to control and configure the system, as well as, to automatically characterize and equalize the channels aiming a more uniform response and hence, better energy resolution. It is worth noting that a sigma of 1.6 keV has been achieved for all 128 channels within the lower range of the ASIC (up to 800 keV), while the ASICs were not optimized to work with the specific detector capacitance. This energy resolution is comparable to state of the art Si hybrid-pixel detector Timepix3 [1]. Using a conservative 6-sigma distance to the electronic noise level it was still obtained a system threshold level of 3 keV . This work provides valuable information for particular applications in which a general purpose strip detector-based system could be used efficiently to replace hybrid pixel detectors.

Inhibitory Interactions and Columnar Inputs to an Object Motion Detector in Drosophila

The direction-selective T4/T5 cells innervate optic-flow processing projection neurons in the lobula plate of the fly that mediate the visual control of locomotion. In the lobula, visual projection neurons coordinate complex behavioral responses to visual features, however, the input circuitry and computations that bestow their feature-detecting properties are less clear. Here, we study a highly specialized small object motion detector, LC11, and demonstrate that its responses are suppressed by local background motion. We show that LC11 expresses GABA-A receptors that serve to sculpt responses to small objects but are not responsible for the rejection of background motion. Instead, LC11 is innervated by columnar T2 and T3 neurons that are themselves highly sensitive to small static or moving objects, insensitive to wide-field motion and, unlike T4/T5, respond to both ON and OFF luminance steps.