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Functionalized and oxidized silicon nanosheets: Customized design for enhanced sensitivity towards relative humidity
摘要： The use of completely oxidized two-dimensional (2D) silicon nanosheets (SiNSs) represents a novel approach for the application of 2D silicon-based materials in the nanoelectronics field. Densely stacked and highly porous oxidized SiNSs (OSiNSs) act as a sensitive layer for humidity detection. Due to the oxidation-caused porosity of the SiNSs and the possibility functionalize the 2D surface with hydrophilic groups, this hybrid material exhibits an extremely good sensitivity towards relative humidity (RH). In this work, precise tuning of the SiNSs’ sensing properties by their functionalization is demonstrated. In particular, the modification with methacrylic acid (MAA) groups, leading to SiNS-MAA, and the subsequent deposition on interdigitated electrodes double the capacitance value in the range of 20-85%RH. These values were achieved after the full oxidation of SiNS-MAA in ambient conditions. The mentioned changes in capacitance are extremely high compared to the response of the so far known common polymer humidity sensors. Contrary to that, this response is neutralized when the SiNSs are functionalized with tert-butyl acrylic acid (tBMA), a rather hydrophobic functional group. The fabricated devices show, how the specific functionalization of SiNSs serves as a reliable tool to provide sensitivity towards RH. Similar approach, based on tuning the functionality, can be applied to achieve e.g., sensor array selectivity. For this purpose, the functional groups on the surface of the nanomaterial can be further modified. Additional molecules with sensitivities towards various surrounding conditions could be attached. Furthermore, these functional molecules can be used for subsequent (bio)molecule immobilization, which can serve as sensitive molecular groups towards surrounding substrates and gases. However, one of the main challenges in sensor technology is to find a highly selective solution: a sensor system capable to differentiate among different vapor species. The described strategy can serve as an access towards new and promising solutions, which can help to face this issue in modern nanomaterials-based technology.
关键词： two-dimensional materials,porous silicon,functionalization,silicon nanosheets,hybrid systems,moisture content
更新于2025-11-21 11:20:48
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Diode Array Near Infrared Spectrometer Calibrations for Composition Analysis of Single Plant Canola (Brassica napus) Seed
摘要： A canola breeder needs an accurate, rapid, non-destructive method for analyzing seeds from a single plant to select the most promising samples for further breeding trials. Near Infrared Spectroscopy (NIRS) is widely used for quantitative analysis of oilseeds in a non-destructive manner. This research was aimed at developing NIRS calibration models for single plant canola seed using a diode array NIRS (950-1650 nm wavelength range), multivariate prediction models, and a mirrored sample cup. Eighteen different NIRS calibration models were developed using 100 samples for each constituent with different pre-processing techniques (mean center, derivatives, variates) and models (PLS, PCR). The relative performance of different calibration models for each constituent was compared using R2, SEP, and ratio performance deviation (RPD) values obtained from the validation set of 30 samples. NIRS models developed using the PLS regression algorithm for moisture content (R2 = 0.97, SEP = 0.32, RPD = 6.13) and oil content (R2 = 0.84, SEP = 0.61, RPD = 4.16) were successful. However, acceptable NIRS models were not obtained for fatty acid and glucosinolates content likely due to limited variability and low levels of the constituent and a narrow wavelength range of the DA-NIR instrument.
关键词： Moisture content,Diode array,Fatty acid composition,Mirrored cup,DA-NIRS,Oil content,Oleic acid,Stearic acid,NIRS calibration model,Palmitic acid
更新于2025-09-23 15:23:52
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Effect of plasma treatment on adhesion strength and moisture absorption characteristics between epoxy molding compound/silicon chip (EMC/chip) interface
摘要： Reliability of interface between two dissimilar materials becomes an important issue due to increasing demands of high-density integrated circuits. Most of failures of semiconductor package occur at the interface between two dissimilar materials in high temperature reflow process, thus, adhesion strength under high temperature should be investigated. In this study, an adhesion shear test jig was newly devised to measure the adhesion strength of epoxy molding compound/Si chip (EMC/chip) interface at high temperature (200 °C). In order to investigate the effect of plasma treatment on adhesion strength and moisture absorption characteristics, the number of plasma treatments was varied. Also, moisture absorption time was varied to observe the moisture uptake and degradation of adhesion strength with respect to plasma treatment number. Atomic force microscope (AFM) was analyzed to verify the surface roughness of silicon chip, and scanning electron microscopy (SEM) was used to observe cross-sectional fractured morphology after adhesion strength test. From this study, it was found that the plasma treatments affect much the adhesion strength and moisture uptake at the interface between the EMC/Chip interface.
关键词： Semiconductor package,Moisture absorption,Adhesion strength,Plasma treatment
更新于2025-09-23 15:23:52
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Visual detection of the moisture content of tea leaves with hyperspectral imaging technology
摘要： Hitherto, the rapid and nondestructive determination of the moisture content of tea leaves is still an unresolved issue because the upward facing surfaces of tea leaves lying on a conveyor belt are randomly chosen by the collapse of the leaves onto their front side or back side. To study the above issue, hyperspectral images of both the front side and back side of tea leaves on a conveyor belt were captured in the lab to simulate a practical production environment, and LS-SVR models with Rv2 values of 0.951 and 0.918 for the front side and back side, respectively, were established based on their characteristic spectral bands. To ensure that the spectrum of each pixel can be correctly imported into its corresponding model, a logistic regression classifier with a correct classification rate of 100 % was designed to identify the front side and back side of the leaves. Finally, a distribution map of the moisture content of the tea leaves was generated successfully according to the following steps: (1) Extracting the average spectrum of each leaf; (2) Identifying which side of the leaf the spectrum belongs to; (3) Importing the adjusted spectrum of each pixel into its corresponding regression model; and (4) Generating a distribution map of the moisture content. This research creatively provides a scheme for detecting the moisture content of tea leaves.
关键词： moisture content,front side,hyperspectral imaging,tea leaf,back side
更新于2025-09-23 15:23:52
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[IEEE IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Valencia (2018.7.22-2018.7.27)] IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Investigating the Relationship Between Shallow Groundwater, Soil Moisture and Land Surface Temperature Using Remotely Sensed Data
摘要： Shallow groundwater has a decisive impact on land surface temperature (LST) and soil moisture (SM). In the present paper relationship between shallow groundwater, SM and LST was studied. For this purpose, the groundwater level and soil moisture were measured in 59 and 39 locations respectively in the southwest of Iran, during June 2016, Simultaneous with the overpass of a Landsat 8 satellite from the study site. After necessary image processing the LST was retrieved from the Landsat image using the split window algorithm. Then relationship between retrieved LST and different field observation were studied. Results show that there is a significant relationship between the groundwater depth and SM with LST. These results indicate that shallow groundwater depth and soil moisture content could be estimated and mapped using the retrieved LST from the satellite imagery.
关键词： Remote Sensing,LST,Landsat 8,Shallow Groundwater,Soil moisture
更新于2025-09-23 15:23:52
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[IEEE IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Valencia (2018.7.22-2018.7.27)] IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - High Spatial Soil Moisture Mapping Using Small Unmanned Aerial System
摘要： Soil moisture is of fundamental importance to many hydrological, biological and biogeochemical processes, plays an important role in the development and evolution of convective weather and precipitation，and impacts precision agriculture, water resource management, and flood runoff prediction. The launch of NASA’s Soil Moisture Active/Passive (SMAP) mission in 2015 provide new passive global measurements of soil moisture and surface freeze/thaw state at fixed crossing times and spatial resolutions of 36 km. There exists a need for measurements of soil moisture on much smaller spatial scales and arbitrary diurnal times for SMAP validation, precision agriculture, flood runoff prediction, evaporation and transpiration studies of boundary layer heat transport, and tundra thaw studies. The Lobe Differencing Correlation Radiometer (LDCR) provides a means of mapping soil moisture on spatial scales as small as several meters (i.e., the height of the platform). Compared with various other proposed methods of validation based on either in situ measurements or existing airborne sensors suitable for manned aircraft deployment, the integrated design of the LDCR on a lightweight small unmanned aerial system (sUAS) can provide sub-watershed (~km scale) coverage at very high spatial resolution (~15 m) suitable for scaling scale studies. The Tempest sUAS, flies at very low operator cost compared to manned aircraft. To demonstrate the LDCR Rev A and Rev B, several flights had been performed during field experiments at the Canton Oklahoma Soilscape site on September 8th and 9th, 2015 and Yuma Colorado Irrigation Research Foundation (IRF) site from June to August 2016, and October 2017. The LDCR antenna temperature and soil moisture maps will be presented, and scientific intercomparisons between LDCR soil moisture data and in-situ measurements will be presented.
关键词： unmanned aerial system,L-band radiometer,soil moisture mapping
更新于2025-09-23 15:23:52
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Rapid, non-destructive determination of ginseng seed moisture content by near infrared spectroscopy technology
摘要： Ginseng seed moisture content (SMC) determination and monitoring are of great importance during seed storage and in trading. The traditional oven-drying method for SMC measurement is accurate but takes both time and labour. The objective of this study was to develop a rapid and non-destructive method for ginseng SMC determination using near infrared (NIR) spectroscopy. Eighteen freshly harvested seed lots stored for different periods (days) were used for NIR model development and 12 commercial seed lots were used for validation of the model. The model developed in the present work had an R2 of 0.9913, residual prediction deviation (RPD) of 11.3 and low root mean square errors assessed by cross-validation (RMSECV; 0.387%). For commercial seed lot measurement, the predicted values of SMC were nearly the same as measured ones, with the relative differences less than 2.96%. In conclusion, NIR spectroscopy suitable for rapid and nondestructive determination of ginseng SMC.
关键词： near infrared spectroscopy,seed moisture content,ginseng
更新于2025-09-23 15:23:52
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[IEEE IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Valencia (2018.7.22-2018.7.27)] IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Field Observations of Temporal Variations of Surface Soil Moisture: Comparison with Insar Sentinel-1 Data
摘要： In this paper we summarize the results of an experiment aiming to compare soil moisture estimates obtained by Sentinel-1 interferometric data with in-situ measurements. The study area, located close to Lisbon in Companhia das Lezirias, Portugal is characterized by a flat topography, large agricultural areas and sparse vegetation. In a test site, four soil moisture sensors were deployed and soil moisture was measured (at a depth of 5 cm) for a period of 7 months in an hourly basis. For the same interval of time and with a temporal resolution of 6 days C-band Sentinel-1 SAR images were interferometrically processed and coherence, phase and phase triplet images were derived. The in-situ soil moisture measurements have been used to predict the analytical interferometric phases, coherences and phase triplets and compared with the measured interferometric phases in both VV and VH polarimetric channels. As a further analysis, a regression analysis of in-situ soil moisture measurement and Sentinel-1 backscattering images has been carried out.
关键词： soil moisture,C-band,SAR interferometry,Sentinel-1
更新于2025-09-23 15:23:52
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[IEEE IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Valencia (2018.7.22-2018.7.27)] IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Accounting for Static and Dynamic Open Water in the Modeling of SMAP Brightness Temperatures Over Peatlands
摘要： Hydrological change in peatlands due to anthropogenic disturbance and global warming can release enormous amounts of greenhouse gas emissions. Passive microwave satellite observations are an opportunity to globally monitor these changes. Abundant static and dynamic open water surfaces in peatlands strongly affect observed brightness temperatures (Tb). Here, we account for these contributions in radiative transfer modeling using NASA's Goddard Earth Observing System Model version 5 (GEOS-5) static open water mask and, for the dynamic open water fraction, the simulated inundated area using a version of the GEOS-5 Catchment land surface model that has been modified for peatland areas (PEAT-CLSM). Modeled Tb is compared against two years of SMAP L-band Tb. Preliminary results indicate: (i) a bias reduction when including the static open water fraction in a simple RTM mixing model, and (ii) significantly improved correlation between modeled and observed Tb when using land surface output from PEAT-CLSM instead of the operational CLSM.
关键词： organic soil,radiative transfer model,soil moisture,L-band,passive microwave
更新于2025-09-23 15:22:29
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Utiliza??o da termografia infravermelha para detec??o de focos de umidade em paredes internas de edifica??es
摘要： The use of infrared thermography has become the theme of studies in several areas of the construction industry. However, research studies on detecting the presence of moisture in buildings are still under development. The main objective of this article was to study the feasibility of the use of thermography in the detection of infiltrations due to accidental causes in internal walls. The methodology consisted of the construction of masonry walls made of ceramic bricks with different coating configurations: uncoated, with plaster, plaster with latex paint, plaster with acrylic base paint and plaster with ceramic set with plaster glue. In each prototype, a drilled pipe was inserted to simulate water leaks. The infiltration progress was verified by means of thermograms, for a period of 2 hours with constant flow, and at 48 hours and one week after the beginning of the simulation. The results confirm that thermography may be effective in detecting the region containing the focus of hidden infiltration, provided the coating is not impermeable. This fact can be observed in the thermal gradients produced in the porous coatings, where ΔT ranged from 2.6 to 3.8 ° C, whereas coatings with waterproof characteristics had a maximum ΔT of 2.2 °C. In addition, the type of coating directly influences the time required for the appearance of the moisture spot to become apparent.
关键词： Infrared thermography. Coating. Infiltration. Moisture. Pathologies in civil construction.
更新于2025-09-23 15:22:29