Flux determination of various gases from farmlands is of great importance. We have applied open-path FT-IR (OPFTIR) spectroscopy combined with a closed-chamber method for measuring greenhouse gases from paddy fields. By applying this technique we were able to measure gases that absorb infrared light on site and simultaneously. To get more quantitative information on the amount of methane from paddy fields, measuring conditions and analyses techniques of observed spectra have been improved. We now get reliable data on the densities of greenhouse gases which are highly space-representative and cannot be got by using conventional techniques. We believe that by proposing appropriate cultivation methods with little environmental load on the basis of the data, we can slow down global warming.
The gradient method is a way to measure gas fluxes from fields. In the method, a gas flux is calculated from the observed altitude dependencies of the wind speed and of the concentration of the target gas. We constructed a new set of equipments for the gradient method consisting of an open-path FT-IR (OP-FTIR) spectrophotometer, a retroreflector (a corner cube mirror array), and four cup anemometers. We expect to get more space representative values of fluxes with the new equipment than with the conventional methods. The equipment enables us to simultaneously determine the fluxes of many atmospheric gases that absorb infrared light. We simultaneously determined fluxes of H2O, CO2, and CH4 gases from a rice field at Honmachi Rice Field of Tokyo University of Agriculture and Technology. Although we found that some improvements were needed to the equipment and analysis techniques to make the observations more reliable, we obtained reasonable values for the fluxes.
We describe spectral classification of pesticide residue. This classification is done by using the attenuated total reflection method (ATR) of Fourier transform infrared spectroscopy (FT-IR). Recently, there has been increased concern about food safety. Not only consumers but also farmers are concerned with levels of pesticide residue. Furthermore, the dispersion of the pesticide (drift) has become an urgent problem. We used ATR Infrared spectroscopy to detect drift and to classify its. Spectral features have been extracted by using soft independent modeling of class analogy (SIMCA) appropriate to the concentration. The spectra of the calibration set were classified into each class on the basis of the concentration, and SIMCA was used to make the classification models. The concentration of pesticide residues of unknown samples was classified by applying the spectra to the classification model.
Sorting, preparing, and packing for strawberry shipment take farmers a lot of time. Therefore, a communal strawberry sorting system at JA was developed and put into practical application. It consists of weight measuring units, a non-destructive quality analyzer which uses near infrared rays to measure sugar and acid content in strawberry, pans carrying strawberries, and conveyors transporting them. All strawberries can be sorted with an efficiency of 3 strawberries per second. By focusing on the distribution of the sugar content in each strawberry, the analyzer predicted with a higher level of accuracy than the SEP 0.5brix% for sugar content and SEP 0.2wt% for acid content. The sorting system is expected to provide farmers with data that will help them to increase the areas that is cultivated by sharing labor more efficiently.
In citrus cultivation, there are problems concerning the quality of fruit, stability of production, and training of new bearers. To solve such problems, cultivating fruits and trees in optimum water conditions as well as saving labor, reducing costs by using precise diagnostic tools. In this research, which has already been practically applied in nondestructive measurement, the leaf water potential was estimated as an index of water stress. A correlation was found between near infrared spectroscopy and leaf water potential, and furthermore, accurate calibration models were obtained. These models were used to estimate the leaf water potential with ranges of about -0.6±0.3 MPa and -1.8±1.0 MPa.
As LEDs have an increasingly higher luminous efficiency LED lamps are expected to become more popular. Therefore, not only luminous efficiency, but also the efficiency of lighting circuits is an important way to improve the efficiency of an entire lighting system. We have therefore invented a new inrush current suppressor which uses a solid state relay (a Photo MOS one), and developed a high-efficient lighting circuit for LED lamps. It has an efficiency that is 80.7∼91.8% higher than conventional lighting circuits and suppresses the inrush current.
Cataract is a typical age-related eye disease. As a cataract progresses, the crystalline lens becomes hazier and visual ability deteriorates. Since the main cause of visual impairment is light scattered by the hazy lens, both brighter environments and hazier lenses worsen visual ability. By focusing this characteristic, we developed two novel methods to estimate the haze factor of crystalline lens through simple visual tasks. In the first method, visual acuity is measured as the amount of scattering light is increased. In the second method, the illuminance of disability surround light is set by an observer. A higher haze factor is estimated with larger deterioration in visual acuity (from the 1st method) or with low illuminance level of disability surround light (from the 2nd method). These estimations of lens' haze factor are expected to serve as easy methods for assessing the progress of a cataract.
We propose UV-A Protection Efficiency (APE) as a new valuable index of UV-A protection provided by fabrics, in addition to a UV-B protection factor UPF (Ultraviolet Protection Factor) recommended by CIE. APE was estimated by determining efficiency of apparel white fabrics in suppressing the formation of strand-breakage in plasmid DNA by sparfloxacin-photosensitization with a black light blue (BLB) lamp and solar UV-A radiation. The lower UV-A transmittance of fabrics showed the higher APE. The close inverse correlation between APE and the transmittance of fabrics at 360 nm was demonstrated with the correlation coefficient of −0.86. These findings support the validity of APE as a useful index of UV-A protection by fabrics. For practical use, APE is ranked to three grades depending on tolerated exposure time: APE from 3.5 to 4.5 is good protection, APE from 4.5 to 5.5 is very good protection, APE more than 5.5 is excellent protection. Present study also states that both APE and UPF are the important factors for protecting the ultraviolet radiation by fabrics.
We developed an electroluminescent (EL) device using boron-doped nanocrystalline silicon (nc-Si) particles that effectively inject a carrier into a luminous layer at a low direct current (DC) voltage of 2.0 V. The injection efficiency of the carrier strongly depends on the boron concentration. The injection quantity of a carrier in an EL device with a high boron concentration of 2.3 at.% was made almost double that of an EL device without boron doping. This was due to both the lowering of the series resistance of the EL device using the doping of boron into nc-Si particles and the coagulation of nc-Si particles using a hydrofluoric acid (HF) treatment. The injection quantity of the carrier can be considerably improved using boron doping into the nc-Si particles and the HF treatment.