Near-infrared reflectance spectroscopic measurement of soil properties

Soil testing is an important task for precision farming and soil quality assessment. However, the standard procedures for soil testing are usually very complex, expensive, and time-consuming. Near-infrared reflectance spectroscopy (NIRS) is a rapid and convenient analytical technique. The main objective of this project was to study the potential of NIRS for analyses of soil analyses. In the study of soil mixtures containing diverse sources of C and N, the results indicated that NIRS can be used to quantify soil C (organic C and inorganic C) and total N, C:N ratios simultaneously. In the study of moist and air-dried soil samples from agricultural fields in Iowa and Minnesota, the results indicated that NIRS predictions of tested soil properties were more accurate for air-dried soils than moist soils; however, the differences were minimal. The overall ability of NIRS to predict soil properties was based on the analyses of 33 properties for over 800 soil samples collected from four Major Land Resources Areas (9, 67, 77, and 105). The results indicated that NIRS can be used to simultaneously estimate soil C and N, moisture, CEC, basal respiration rate, potentially mineralizable N, particle size distribution, and some extractable and exchangeable cations with acceptable accuracy. Based on these studies NIRS has the potential to be used as a fast and nondestructive soil testing technique for both moist and air-dried soils

Artificial Gauge Field and Quantum Spin Hall States in a Conventional Two-dimensional Electron Gas

Based on the Born-Oppemheimer approximation, we divide total electron Hamiltonian in a spinorbit coupled system into slow orbital motion and fast interband transition process. We find that the fast motion induces a gauge field on slow orbital motion, perpendicular to electron momentum, inducing a topological phase. From this general designing principle, we present a theory for generating artificial gauge field and topological phase in a conventional two-dimensional electron gas embedded in parabolically graded GaAs/In$_{x}$Ga$_{1-x}$As/GaAs quantum wells with antidot lattices. By tuning the etching depth and period of antidot lattices, the band folding caused by superimposed potential leads to formation of minibands and band inversions between the neighboring subbands. The intersubband spin-orbit interaction opens considerably large nontrivial minigaps and leads to many pairs of helical edge states in these gaps.Comment: 9 pages and 4 figure

Optimization Study of Small-Scale Solar Membrane Distillation Desalination Systems (s-SMDDS)

[[abstract]]Membrane distillation (MD), which can utilize low-grade thermal energy, has been extensively studied for desalination. By incorporating solar thermal energy, the solar membrane distillation desalination system (SMDDS) is a potential technology for resolving energy and water resource problems. Small-scale SMDDS (s-SMDDS) is an attractive and viable option for the production of fresh water for small communities in remote arid areas. The minimum cost design and operation of s-SMDDS are determined by a systematic method, which involves a pseudo-steady-state approach for equipment sizing and dynamic optimization using overall system mathematical models. Two s-SMDDS employing an air gap membrane distillation module with membrane areas of 11.5 m2 and 23 m2 are analyzed. The lowest water production costs are $5.92/m3 and$5.16/m3 for water production rates of 500 kg/day and 1000 kg/day, respectively. For these two optimal cases, the performance ratios are 0.85 and 0.91; the recovery ratios are 4.07% and 4.57%. The effect of membrane characteristics on the production cost is investigated. For the commercial membrane employed in this study, the increase of the membrane mass transfer coefficient up to two times is beneficial for cost reduction.[[notice]]補正完畢[[incitationindex]]SCI[[incitationindex]]EI[[booktype]]電子

Construction and verification of digital electronics contestants' indicators for vocational education in Taiwan

No AbstractKeywords: competency indicator, digital electronics, important-performance analysis, skill competitio

THE EFFECT OF FOOT POSITION ON KINETICS OF LOWER LIMBS DURING SQUAT

The purposes of this study were to evaluate the effects of the foot position on the joint forces and moments of lower limbs during squat. Eleven male weightlifters were recruited in this study to perform squat with different foot position (forward position and toe-out 20 degrees). The VICON motion analysis system and two KISTLER force platforms were used to record the kinematical and kinetic data during squat. The results showed that the ankle joint maximal shear force, maximal adduction moment, external rotation moment and knee external rotation moment during squat with foot forward position were significantly greater than the results in toe-out position. Squat with foot forward position could be suggested to improve the ankle stability in rehabilitative training

Effects of Convolutional Autoencoder Bottleneck Width on StarGAN-based Singing Technique Conversion

Singing technique conversion (STC) refers to the task of converting from one voice technique to another while leaving the original singer identity, melody, and linguistic components intact. Previous STC studies, as well as singing voice conversion research in general, have utilized convolutional autoencoders (CAEs) for conversion, but how the bottleneck width of the CAE affects the synthesis quality has not been thoroughly evaluated. To this end, we constructed a GAN-based multi-domain STC system which took advantage of the WORLD vocoder representation and the CAE architecture. We varied the bottleneck width of the CAE, and evaluated the conversion results subjectively. The model was trained on a Mandarin dataset which features four singers and four singing techniques: the chest voice, the falsetto, the raspy voice, and the whistle voice. The results show that a wider bottleneck corresponds to better articulation clarity but does not necessarily lead to higher likeness to the target technique. Among the four techniques, we also found that the whistle voice is the easiest target for conversion, while the other three techniques as a source produce more convincing conversion results than the whistle.Comment: The original edition of this paper will be published in the CMMR 2023 Proceedings. This ArXiv publication is a cop