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A multi-mode excitation hardness prediction method based on Controlled Laser Air-Force Detection (CLAFD) technique
摘要： A novel material hardness testing method was proposed based on controlled laser air-force detection (CLAFD) technique. Polyurethane was chosen as the study object. Multi-mode excitation was adopted. Partial least square as the modeling method was used to build the hardness prediction model on the data of laser displacement. Different preprocessing methods were carried out for eliminating the noise of the original data. The results showed the multiplicative scattering model analysis for the data of stress relaxation mode. The results showed that the hardness could be predicted with high precision. The relationship coefficients of the prediction set (Rp) was above 0.90, and the residual prediction deviation (RPD) was more than 2. Furthermore, the Rp of the transient was 0.93, the RPD was 2.51, the excitation time was 1 s, showing that the transient mode performed with precision in high-speed hardness detection. The highest precision was based on the stress relaxation mode, so we did further study on the interval correction (MSC) had the best performance. Among four modes, the relationship coefficients of the prediction set (Rp) was up to 0.99, and the RPD was 3.54 when the time of the stress relaxation mode lasted 60 s. Based on the results above, the prediction ability would improve further when the relaxation time is increased. The study will provide a new real-time, non-destruction and cross-contamination free hardness detection method for material science, especially for those materials such as artificial biological tissue, function food products, etc.
关键词： Hardness prediction,Biological tissue,Cross-contamination-free,Multi-mode excitation,Polyurethane,Controlled laser air-force detection (CLAFD)
更新于2025-09-12 10:27:22
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Effect of energy parameters of pulsed laser welding of Zr-1%Nb alloy on metal contamination with gases and properties of welds
摘要： Effect of pulsed laser welding parameters (pulse energy and duration, frequency, welding speed and, as a result, overlapping factor) on properties of E110 (Zr-1%Nb) alloy welds is presented. Butt welded joints of two identical plates with a thickness of 0.5 mm were investigated. EDS analysis of a surface layer of the welds was done, initial hydrogen concentration in the weld metal was measured and influence of absorbed gases (oxygen, nitrogen, carbon and hydrogen) on tensile strength, microhardness, hydrogen absorption rate and corrosion resistance of the welds was evaluated. The weld metal contained initial hydrogen concentration within the limits set by standards. However, mixing argon flows with atmospheric gases caused the weld metal contamination with oxygen, nitrogen and carbon. As a result, inclusions of complex chemical composition and surface branching microcracks were formed. They were stress raisers where weld failures occurred. Furthermore, it was the reason of increased hydrogen absorption rate and decreased corrosion resistance of the weld metal. The obtained results showed that absence of discoloration on surfaces of the welded joints did not guarantee metal purity and, as a consequence, required performance properties. Future research is required to determine the optimal overlapping factor; shielding gas compositions (Ar, He or their mixture) and flow rates; configuration and inclination angle of nozzles as well as distance from the nozzles to the weld zone.
关键词： Pulsed laser welding,Metal contamination,Corrosion resistance,Hydrogen content,Zirconium alloy,Hydrogen absorption rate
更新于2025-09-12 10:27:22
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Degradation of Mg-doped zinc oxide buffer layers in thin film CdTe solar cells
摘要： Cadmium Sulphide is the conventional n-type bu?er layer used in thin ?lm Cadmium Telluride solar cells. It is well known that Cadmium Sulphide causes optical losses and sulphur di?uses into the absorber during high temperature activation. Sputter-deposited Mg-doped ZnO (MZO) has been shown to be an attractive bu?er layer for Cadmium Telluride solar cells due to its transparency and tuneable band gap. It is also stable to high temperature processing and avoids di?usion of elements into the cadmium telluride absorber during the cadmium chloride activation treatment. However, degradation is observed in solar cells incorporating MZO bu?er layers. Analysis of the MZO ?lm surface potential has revealed signi?cant ?uctuations in the thin ?lm work function once the layer is exposed to the atmosphere following deposition. These ?uctuations are attributed to the high reactivity to water vapour of the MgO contained in the MZO ?lms. This has been analysed using X-ray Photoelectron Spectroscopy to determine corresponding changes in the surface chemistry. The Zinc Oxide component is relatively stable, but the analysis shows that MgO forms a Mg(OH)2 layer on the MZO surface which forms a secondary barrier at the MZO/CdTe interface and/or at the interface between MZO and the Fluorine-doped SnO2. This a?ects the Fill Factor and as a consequence it degrades the conversion e?ciency.
关键词： Surface contamination,Degradation,Thin ?lm solar cells,Cadmium telluride,Magnesium-doped zinc oxide,Hydroxide,Bu?er
更新于2025-09-11 14:15:04
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Applications of Laser-Induced Breakdown Spectroscopy for Soil Characterization, Part II: Review of Elemental Analysis and Soil Classification
摘要： In-field soil health assessments, including plant nutrients and toxic elements, are needed and could improve the sustainability of agriculture production. Among the available analytical techniques for these analyses, laser-induced breakdown spectroscopy (LIBS) has become one of the most promising techniques for real-time soil analysis at low cost and without the need of reagents. The first part of this two-part review (Part I, Villas-Boas et al., 2019) in this issue focused on the fundamentals of LIBS for soil analysis and its use for soil chemical and physical characterization. Our objectives in this review article (Part II) are to review (i) the main applications of LIBS in the determination of soil carbon (C), nutrients and toxic elements, spatial elemental mapping, and (ii) its use in soil classification. Traditional and more recent techniques will be compared to LIBS, considering their advantages and disadvantages. LIBS is a promising, versatile technique for detecting many elements in soil samples, requires little or no sample preparation, takes only a few seconds per sample, and has a low cost per sample compared to other techniques. However, overcoming matrix effects is a challenge for LIBS applications in soil analysis, since most studies are conducted with limited changes in the matrix. In spite of the limitation of matrix effects, a typical LIBS system has a limit of detection of 0.3, 0.6, 4, 7, 10, 18, 46, and 89 mg kg-1 for Mo, Cu, Mg, Mn, Fe, Zn, K, and Ca, respectively. LIBS holds potential for real-time in-field spatial elemental analysis of soils and practical applications in precision farming with proper calibration. This could lead to immediate diagnoses of contaminated soil and inefficient nutrient supplies and facilitate well-informed soil management, increasing agricultural production while minimizing environmental impacts.
关键词： soil contamination,soil fertility,rhizosphere,toxic elements,spatial elemental mapping,SOM,precision agriculture,Plant nutrients,soil carbon
更新于2025-09-11 14:15:04
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Strategies for Reducing Particle Defects in Ti and TiN Thin-Film Deposition Processes
摘要： Generation of particle defects in semiconductor manufacturing is inevitable, but it has to be minimized to enhance IC yield. There are various causes for the generation of particle defects in different semiconductor manufacturing processes, such as diffusion, thin-film deposition, lithography, etch, and clean. In this work, primary defect generation mechanisms in thin-film deposition processes, such as ALD TiN, RFPVD Ti, and PVD TiN, are discussed. Various strategies, such as periodic clean optimization, on-load clean, idle pasting, periodic pasting optimization, kit life optimization, target burning optimization, and kit hardware selection that reduce the generation of defects in the thin-film deposition processes are presented. This work also discusses hardware-induced surface defect and solutions to reduce them.
关键词： Conductive films,IC manufacturing,Metallic materials,Contamination free manufacturing,Thin films
更新于2025-09-10 09:29:36
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165 To determine if hand held near infrared spectroscopy can be used to measure corn particle size, corn particle distribution and corn moisture
摘要： With the introduction of porcine epidemic diarrhea virus (PEDV) to the United States in 2013 and the subsequent identification of feed as a route of transmission, identifying sources of feedstuff contamination and methods to reduce the risk of transmission at feed mills has become paramount. As with other biological hazards, contaminated ingredients can easily lead to cross-contamination of finished feeds and contamination throughout the facility. Therefore, the objective of this study was to monitor equipment and environmental contamination after manufacturing PEDV-positive feed and after the production of subsequent PEDV-negative feed. PEDV-positive feed (50 kg with 4.5 × 104 TCID50/g, Ct 11) was mixed in a 0.11m3 paddle mixer, discharged into a bucket elevator, and collected. Following processing of the contaminated feed, 4 subsequent batches of PEDV-free feed (sequence 1–4) were processed through the mixer and bucket elevator with no decontamination between batches to mimic commercial feed production. Porcine epidemic diarrhea virus contamination of equipment and surrounding areas were monitored via the collection of swabs that were analyzed via quantitative PCR (qPCR) for PEDV RNA. Swabs were collected from equipment and facility surfaces prior and after processing contaminated feed and after processing subsequent sequenced batch diets. Monitored areas for equipment included the interior of the mixer and bucket elevator. Facility areas included high and low foot traffic areas (concrete), floor drain (concrete), worker boot bottoms (rubber), table (metal), and door (metal). Three replications of contaminated feed and subsequent sequence batch diet processing was completed, with equipment and facility decontamination between replicates. Following qPCR analysis, Ct values ≤ 40 were considered PEDV-positive and all numerical data was converted to ± for statistical analysis via PROC MIXED procedure of SAS. The interactions feed contact surface by sequence were found to be significant (P < 0.01). All swabs collected from equipment surfaces after processing of PEDV-positive feed were positive for PEDV, while 16 of 18 of the collected facility swabs were positive for PEDV RNA. Following processing of the first sequence batch diet, 100% of equipment surfaces and 88.9% of facility surfaces were positive for PEDV. Surprisingly, a large percentage of equipment and facility surfaces remained PEDV-positive through the processing of the subsequent sequence batch diets. Furthermore, all swabs collected from concrete and rubber surfaces remained PEDV-positive through all processing of all diets. This study demonstrates the extent of equipment and facility contamination that could occur in a feed manufacturing facility after processing of PEDV-contaminated feed.
关键词： contamination,feed mill,PEDV
更新于2025-09-10 09:29:36
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Non-neuronal evoked and spontaneous hemodynamic changes in the anterior temporal region of the human head may lead to misinterpretations of functional near-infrared spectroscopy signals
摘要： Several functional near-infrared spectroscopy (fNIRS) studies report their findings based on changes of a single chromophore, usually concentration changes of oxygenated hemoglobin ([O2Hb]) or deoxygenated hemoglobin (HHb). However, influence of physiological actions may differ depending on which element is considered and the assumption that the chosen measure correlates with the neural response of interest might not hold. By assessing the correlation between [O2Hb] and [HHb] in task-evoked activity as well as resting-state data, we identified a spatial dependency of non-neuronal hemodynamic changes in the anterior temporal region of the human head. Our findings support the importance of reporting and discussing fNIRS outcomes obtained with both chromophores ([O2Hb] and [HHb]), in particular, for studies concerning the anterior temporal region of the human head. This practice should help to achieve a physiologically correct interpretation of the results when no measurements with short-distance channels are available while employing continuous-wave fNIRS systems.
关键词： superficial temporal vessels,temporal lobe,optical neuroimaging,temporalis muscle,scalp blood flow,extracerebral signal contamination,functional near-infrared spectroscopy
更新于2025-09-10 09:29:36
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Pansharpening for Cloud-Contaminated Very High-Resolution Remote Sensing Images
摘要： The optical remote sensing images not only have to make a fundamental tradeoff between the spatial and spectral resolutions, but also are inevitable to be polluted by the clouds; however, the existing pansharpening methods mainly focus on the resolution enhancement of the optical remote sensing images without cloud contamination. How to fuse the cloud-contaminated images to achieve the joint resolution enhancement and cloud removal is a promising and challenging work. In this paper, a pansharpening method for the challenging cloud-contaminated very high-resolution remote sensing images is proposed. Furthermore, the cloud-contaminated conditions for the practical observations with all the thick clouds, the thin clouds, the haze, and the cloud shadows are comprehensively considered. In the proposed methods, a two-step fusion framework based on multisource and multitemporal observations is presented: 1) the thin clouds, the haze, and the light cloud shadows are proposed to be first jointly removed and 2) a variational-based integrated fusion model is then proposed to achieve the joint resolution enhancement and missing information reconstruction for the thick clouds and dark cloud shadows. Through the proposed fusion method, a promising cloud-free fused image with both high spatial and high spectral resolutions can be obtained. To comprehensively test and verify the proposed method, the experiments were implemented based on both the cloud-free and cloud-contaminated images, and a number of different remote sensing satellites including the IKONOS, the QuickBird, the Jilin (JL)-1, and the Deimos-2 images were utilized. The experimental results confirm the effectiveness of the proposed method.
关键词： remote sensing,image fusion,Pansharpening,cloud contamination,integrated model
更新于2025-09-09 09:28:46
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Renewal Mechanism of UV-Ozone-Cleaning Process on Contaminated Screen-Printed Carbon Electrodes
摘要： Screen-printed carbon electrode (SPCE) has been extensively applied in electrochemical (EC) detection due to its excellent characteristics and low cost. However, SPCE is more likely to be contaminated that seriously affects the sensitivity and reproducibility of detection. In this paper, UV-ozone-cleaning process was utilized to solve this problem. Renewal mechanism of UV-ozone-cleaning on contaminated SPCE was ?rstly investigated in detail, in which the level of SPCE contamination was represented by interfacial impedance. Both scanning electron microscopy and X-ray photoelectron spectroscopy were employed to evaluate the surface morphology and chemical constituents of SPCE respectively. The results indicate that the signi?cant EC enhancement was mainly attributed to the removal of contaminants, the increase of both reaction area and surface oxygen functional groups. To further demonstrate the renewal effect, the determination of nicotinamide adenine dinucleotide was performed. Compared with the contaminated SPCE, the UV-ozone-cleaned SPCE exhibits better EC response that the anodic peak current increased by 6～28% and the sensitivity increased from 13.31 to 19.11 μA · mM?1. Moreover, the cleaned SPCE shows good reproducibility with the low standard deviation of peak current and oxidation potential.
关键词： screen-printed carbon electrode,electrochemical detection,contamination,renewal mechanism,UV-ozone-cleaning
更新于2025-09-09 09:28:46
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Ratiometric Monitoring of Thorium Contamination in Natural Water using a Dual-Emission Luminescent Europium Organic Framework
摘要： Traditional analytical methods of thorium contamination suffer from several disadvantages such as time-consuming procedure and equipment-intensive nature, leading to substantial challenges in rapid and onsite monitoring of thorium concentration in complex natural water systems. We report here the first case of luminescent metal organic framework based probe (ThP-1) for highly sensitive and selective self-calibrated sensing of Th4+ contamination in natural fresh water media with a notably facilitated detection procedure. The detection limit of ThP-1 was determined to be 24.2 μg/L, much lower than the thorium contamination standard of 246 μg/L in drinking water defined by the World Health Organization. Importantly, the detection procedure based on the rarely reported self-calibration manner is greatly beneficial on improving the detection accuracy. The self-calibrated luminescence evolution process is of great anti-interference ability capable of detecting thorium contamination in a wide concentration range from 24.2 μg/L to 300 mg/L, which can not be achieved directly by the traditional methods. The Th4+-selective luminescence response originates from the selective uptake and efficient enrichment of Th4+ by the host framework of ThP-1 through inner-sphere coordination, which is further confirmed by batch experiments, X-ray absorption spectroscopic study, and DFT calculations.
关键词： natural water,Th4+ detection,self-calibrated sensing,thorium contamination,luminescent metal organic framework
更新于2025-09-09 09:28:46