Effect of sound insulation on noise reduction in an agricultural tractor cab.

Tractor cab interior noise is a risk factor that degrades operators' work performance and threatens their health; therefore, the noise must be reduced to ensure farmworkers' safety and efficiency. Cab interior noise can be classified as structure-borne noise and air-borne noise. Structure-borne noise has been extensively studied. However, although air-borne noise greatly contributes to cab interior noise, detailed frequency-domain analyses have not been performed. In this study, the components of cab interior noise were identified in the frequency domain through an order analysis, which helped improve the sound insulation of the cab and reduce the effects of air-borne noise. A test was performed while driving a tractor on a chassis dynamometer in a semi-anechoic chamber for reproducible measurement and evaluation. The A-weighted sound pressure was transformed by a fast Fourier transform algorithm, and its order was tracked by the engine speed signal. In addition, a direct path was identified by acoustic images using a sound camera. The contributions of major noise sources were identified through an order analysis. We proved that air-borne noise significantly contributes to the interior noise of tractor cabs and that improvement of the cab sound insulation is an effective noise-reduction technique.

Analysis of the Effect of Tillage Depth on the Working Performance of Tractor-Moldboard Plow System under Various Field Environments.

The purpose of this study was to analyze the tillage depth effect on the tractor-moldboard plow systems in various soil environments and tillage depths using a field load measurement system. A field load measurement system can measure the engine load, draft force, travel speed, wheel axle load, and tillage depth in real-time. In addition, measurement tests of soil properties in the soil layer were preceded to analyze the effect of field environments. The presented results show that moldboard plow at the same tillage depth had a wide range of influences on the tractor's working load and performance under various environments. As the draft force due to soil-tool interaction occurred in the range of 5.6-17.7 kN depending on the field environment, the overall mean engine torque and rear axle torque were up to 2.14 times and 1.67 times higher in hard and clayey soil, respectively, than in soft soil environments. In addition, the results showed tractive efficiency of 0.56-0.73 and were analyzed to have a lugging ability of 67.8% with a 44% maximum torque rise. The engine power requirement in hardpan was similar within 3.6-9.6%, but the power demand of the rear axle differed by up to 18.4%.

One-step immunoassay without washing steps for influenza A virus detection using ISFET.

A one-step immunoassay for influenza A virus detection was developed using two different microbeads and a filter-inserted bottle. Two bead types with diameters of 15 (capture bead) and 3 (detection bead) µm were prepared to specifically detect influenza A virus. Anti-influenza A virus antibodies were coated on both bead types, whereas urease was immobilized only on the detection bead. An influenza A-positive sample could form a sandwich complex with the capture and detection beads; this complex would not pass through the filter, which had a controlled pore size. As the detection bead was used at a limiting concentration, it would be prevented from crossing the filter; thus, it would further react with the substrate urea and consequently increase the pH. An influenza A-negative sample would fail to form the sandwich complex in the presence of the capture and detection beads. Accordingly, the detection bead would pass through the filter into the urea buffer and increase the pH. The pH change in the urease reaction could be quantitatively measured by an indicator such as phenol red or using ion-selective field-effect transistor (ISFET). This one-step immunoassay was used for the detection of influenza A virus in real samples. The receiver operating characteristic (ROC) plot analysis showed an area under the curve (AUC) value of 0.931; the sensitivity and specificity of the assay was 80% and 90%, respectively, at a cutoff value of 0.9986. These results demonstrate that the one-step immunoassay could increase the sensitivity of influenza A virus detection in real samples.

Analysis of Tillage Depth and Gear Selection for Mechanical Load and Fuel Efficiency of an Agricultural Tractor Using an Agricultural Field Measuring System.

This study was conducted to analyze the effects of tillage depth and gear selection on the mechanical load and fuel efficiency of an agricultural tractor during plow tillage. In order to analyze these effects, we developed an agricultural field measuring system consisting of a load measurement part (wheel torque meter, proximity sensor, and real-time kinematic (RTK) global positioning system (GPS)) and a tillage depth measurement part (linear potentiometer and inclinometer). Field tests were carried out using moldboard plows with a maximum tillage depth of 20 cm and three gear selections (M2H, M3L, and M3H) in a rice stubble paddy field for plow tillage. The average travel speed and slip ratio had the lowest M2H and the highest M3L. M3H had the highest theoretical speed, but the travel speed was 0.13 km/h lower than M3L due to the reduction in the axle rotational speed at deep tillage depth. Regarding engine load, the higher the gear, the greater the torque and the lower the axle rotation speed. The front axle load was not significantly affected by the tillage depth as compared to other mechanical parts, except for the M3H gear. The rear axle load generated about twice the torque of the front wheel and overall, it tended to show a higher average rear axle torque at higher gear selection. The rear axle load and fuel rate were found to be most affected by the combination of the tillage depth and gear selection combination. Overall, field test results show that the M3H had the highest fuel efficiency and a high working speed while overcoming high loads at the same tillage depth. In conclusion, M3H is the most suitable gear stage for plow cultivation, and the higher the gear stage and the deeper the tillage depth during plowing, the higher the fuel efficiency. The results of this study will be useful for analyzing mechanical load and fuel efficiency during farm operations. In a future study, we will conduct load analysis studies in other farming operations that consider various soil mechanics factors as well as tillage depths and gear selections.

Development of a Real-Time Tillage Depth Measurement System for Agricultural Tractors: Application to the Effect Analysis of Tillage Depth on Draft Force during Plow Tillage.

The objectives of this study were to develop a real-time tillage depth measurement system for agricultural tractor performance analysis and then to validate these configured systems through soil non-penetration tests and field experiment during plow tillage. The real-time tillage depth measurement system was developed by using a sensor fusion method, consisting of a linear potentiometer, inclinometer, and optical distance sensor to measure the vertical penetration depth of the attached implement. In addition, a draft force measurement system was developed using six-component load cells, and an accuracy of 98.9% was verified through a static load test. As a result of the soil non-penetration tests, it was confirmed that sensor fusion type A, consisting of a linear potentiometer and inclinometer, was 6.34-11.76% more accurate than sensor fusion type B, consisting of an optical distance sensor and inclinometer. Therefore, sensor fusion type A was used during field testing as it was found to be more suitable for use in severe working environments. To verify the accuracy of the real-time tillage depth measurement system, a linear regression analysis was performed between the measured draft and the predicted values calculated using the American Society of Agricultural and Biological Engineers (ASABE) standards-based equation. Experimental data such as traveling speed and draft force showed that it was significantly affected by tillage depth, and the coefficient of determination value at M3-Low was 0.847, which is relatively higher than M3-High. In addition, the regression analysis of the integrated data showed an R-square value of 0.715, which is an improvement compared to the accuracy of the ASABE standard prediction formula. In conclusion, the effect of tillage depth on draft force of agricultural tractors during plow tillage was analyzed by the simultaneous operation of the proposed real-time tillage depth measurement system and draft force measurement system. In addition, system accuracy is higher than the predicted accuracy of ±40% based on the ASABE standard equation, which is considered to be useful for various agricultural machinery research fields. In future studies, real-time tillage depth measurement systems can be used in tractor power train design and to ensure component reliability, in accordance with agricultural working conditions, by predicting draft force and axle loads depending on the tillage depth during tillage operations.

Detection of starch adulteration in onion powder by FT-NIR and FT-IR spectroscopy.

Adulteration of onion powder with cornstarch was identified by Fourier transform near-infrared (FT-NIR) and Fourier transform infrared (FT-IR) spectroscopy. The reflectance spectra of 180 pure and adulterated samples (1-35 wt % starch) were collected and preprocessed to generate calibration and prediction sets. A multivariate calibration model of partial least-squares regression (PLSR) was executed on the pretreated spectra to predict the presence of starch. The PLSR model predicted adulteration with an R(p)2 of 0.98 and a standard error of prediction (SEP) of 1.18% for the FT-NIR data and an R(p)2 of 0.90 and SEP of 3.12% for the FT-IR data. Thus, the FT-NIR data were of greater predictive value than the FT-IR data. Principal component analysis on the preprocessed data identified the onion powder in terms of added starch. The first three principal component loadings and ß coefficients of the PLSR model revealed starch-related absorption. These methods can be applied to rapidly detect adulteration in other spices.

Development of a Smartphone-based reading system for lateral flow immunoassay.

This study was conducted to develop and evaluate the performance of the Smartphone-based reading system for the lateral flow immunoassay (LFIA). Smartphone-based reading system consists of a Samsung Galaxy S2 Smartphone, Smartphone application, and a LFIA reader. LFIA reader is composed of the close-up lens with a focal length up to 30 mm, white LED light, lithium polymer battery, and main body. The Smartphone application for image acquisition and data analysis was developed on the Android platform. The standard curve was obtained by plotting the measured P(T)/P(c) or A(T)/A(c) ratio versus Salmonella standard concentration. The mean, standard deviation (SD), recovery, and relative standard deviation (RSD) were also calculated using additional experimental results. These data were compared with that obtained from the benchtop LFIA reader. The LOD in both systems was observed with 10(6) CFU/mL. The results show high accuracy and good reproducibility with a RSD less than 10% in the range of 10(6) to 10(9) CFU/mL. Due to the simple structure, good sensitivity, and high accuracy of the Smartphone-based reading system, this system can be substituted for the benchtop LFIA reader for point-of-care medical diagnostics.

Development of nanogold-based lateral flow immunoassay for the detection of ochratoxin A in buffer systems.

Ochratoxin A (OTA), classified as a possible human renal carcinogen (group 2B), is a potent toxin as to cause the nephropathy. Many methods have been proposed and reviewed for OTA determination in food and agricultural products. However, current analytical procedures of mycotoxin are based on the time-delayed analysis. To reduce the contamination of OTA during distribution and storage of food and feeds, a rapid and easy-to-use detection method is required. The strip assay is an easy and fast detection method that is very reliable and cheap in production. The purpose of this study was to improve the sensitivity of strip sensor by simplifying the manufacturing steps and detection reading. Feasibility of strip assay detection of OTA was determined by color appearance of test line that was produced by the binding between OTA-BSA conjugates and gold antibody particles. However, in this study, strip assays were improved the efficacy of detection by conjugating with nanoparticles and OTA-BSA conjugates, instead of antibody. By different optimization steps in strip manufacturing and the application of the label on the strips, an increase in sensitivity and applicability was accomplished. The method uses a low cost test device consisting of a conjugation pad, membrane, sample pad, and absorbent pad. OTA-BSA and their conjugates with colloidal gold nanoparticles were prepared. The detection was based on the competition of OTA in a sample and an OTA-BSA on the colloidal particle surfaces for the binding to antibody of OTA immobilized on a membrane. It allows direct analysis of sample containing 10% methanol in phosphate buffered saline. The limit of detection obtained was 10 ng/ml for OTA. The cross reactivity of OTA strip assays with Aflatoxin B1 (AFB1) was examined. When 10, 100 ng/ml of AFB1 was tested, non-specific binding was not observed in the test strip.

Comparative study of binding constants from Love wave surface acoustic wave and surface plasmon resonance biosensors using kinetic analysis.

Biosensors are used in a variety of fields for early diagnosis of diseases, measurement of toxic contaminants, quick detection of pathogens, and separation of specific proteins or DNA. In this study, we fabricated and evaluated the capability of a high sensitivity Love wave surface acoustic wave (SAW) biosensor. The experimental setup was composed of the fabricated 155-MHz Love wave SAW biosensor, a signal measurement system, a liquid flow system, and a temperature-control system. Subsequently, we measured the lower limit of detection (LOD) of the 155-MHz Love wave SAW biosensor, and calculated the association and dissociation constants between protein G and anti-mouse IgG using kinetic analysis. We compared these results with those obtained using a commercial surface plasmon resonance (SPR) biosensor. We found that the LOD of the SAW biosensor for anti-mouse IgG and mouse IgG was 0.5 and 1 microg/ml, respectively, and the resultant equilibrium association and dissociation constants were similar to the corresponding values obtaining using the commercial SPR biosensor. Thus, we conclude that the fabricated 155-MHz Love wave SAW biosensor exhibited the high sensitivity of the commercial SPR biosensor and was able to analyze the binding properties of the ligand and receptor by kinetic analysis similarly to the commercial SPR biosensor.

Identification of Salmonella Typhimurium-specific DNA aptamers developed using whole-cell SELEX and FACS analysis.

Conventional methods for detection of infective organisms, such as Salmonella, are complicated and require multiple steps, and the need for rapid detection has increased. Biosensors show great potential for rapid detection of pathogens. In turn, aptamers have great potential for biosensor assay development, given their small size, ease of synthesis and labeling, lack of immunogenicity, a lower cost of production than antibodies, and high target specificity. In this study, ssDNA aptamers specific to Salmonella Typhimurium were obtained by a whole bacterium-based systematic evolution of ligands by exponential enrichment (SELEX) procedure and applied to probing S. Typhimurium. After 10 rounds of selection with S. Typhimurium as the target and Salmonella Enteritidis, Escherichia coli and Staphylococcus aureus as counter targets, the highly enriched oligonucleic acid pool was sorted using flow cytometry. In total, 12 aptamer candidates from different families were sequenced and grouped. Fluorescent analysis demonstrated that aptamer C4 had particularly high binding affinity and selectivity; this aptamer was then further characterized.

Electromagnetic field-induced converse cell growth during a long-term observation.

PURPOSE: Professional and public concern about the potential adverse effects of man-made electromagnetic fields (EMF) on the human body has dramatically expanded in recent years. Despite numerous attempts to investigate this issue, the long-standing challenge of reproducibility surrounding alternating EMF effects on human health remains unresolved. Our chief aim was to investigate a plausible mechanism for this phenomenon. MATERIALS AND METHODS: Growth of cultured human cancer cells, DU145 and Jurkat, exposed to power frequency magnetic field (MF) (60 Hz, 1 mT) for 3 days, was determined using a 2-(4-Iodophenyl)- 3-(4-nitrophenyl)-5-(2,4-disulfophenyl)-2H-tetrazolium (WST-1) assay and a trypan blue exclusion assay. This experiment was repeated at incubators long-term monitoring period up to 5.3 years. A periodogram analysis was performed to investigate periodic patterns in the MF and sham effects on cell growth. RESULTS: Unlike conventional assumptions, the MF effect on growth in both cell types was promotive or suppressive in a period-dependent manner. The converse cell growth induced by the MF was consistent in incubators, with little variation. CONCLUSIONS: Spatiotemporal evidence suggests that the period-dependent converse cell growth by the MF may contribute to the poor reproducibility and explain the adverse effects observed in previous experimental and epidemiological investigations. Additionally, the novel approach of this study may be applied to design features required to experimentally determine the effects of EMF on living organisms in a convincing manner.

Performance improvement of the one-dot lateral flow immunoassay for aflatoxin B1 by using a smartphone-based reading system.

This study was conducted to develop a simple, rapid, and accurate lateral flow immunoassay (LFIA) detection method for point-of-care diagnosis. The one-dot LFIA for aflatoxin B1 (AFB1) was based on the modified competitive binding format using competition between AFB1 and colloidal gold-AFB1-BSA conjugate for antibody binding sites in the test zone. A Smartphone-based reading system consisting of a Samsung Galaxy S2 Smartphone, a LFIA reader, and a Smartphone application for the image acquisition and data analysis. The detection limit of one-dot LFIA for AFB1 is 5 µg/kg. This method provided semi-quantitative analysis of AFB1 samples in the range of 5 to 1,000 µg/kg. Using combination of the one-dot LFIA and the Smartphone-based reading system, it is possible to conduct a more fast and accurate point-of-care diagnosis.

Mass sensitivity calculation of the protein layer using love wave SAW biosensor.

Love waves, a variety of surface acoustic waves (SAWs), can be used to detect very small biological surface interactions and so have a wide range of potential applications. To demonstrate the practicality of a Love wave SAW biosensor, we fabricated a 155-MHz Love wave SAW biosensor and compared it with a commercial surface Plasmon resonance (SPR) using glycerol-water solution with known densities and viscosities to calibrate the response signals of the biosensors. And the mass per unit area of anti-mouse IgG bound with protein G onto the sensitive layer of the biosensor was calculated on the basis of the calibration result. The sensitivity of the Love wave SAW biosensor was the same as or greater than that of the SPR biosensor. Furthermore, the Love wave SAW biosensor was capable of measuring a much wider range of viscosities than the SPR biosensor. Although the operating principle of the Love wave SAW biosensor is completely different from that of the SPR biosensor, the subtle changes in the viscoelastic properties of the biological layer that accompany biological binding reactions on the sensitive layer can be monitored and measured in the same ways as with the SPR biosensor.

A Gold Nanoparticle and Aflatoxin B1-BSA Conjugates Based Lateral Flow Assay Method for the Analysis of Aflatoxin B1.

A rapid and simple immuno-chromatographic assay was developed to detect aflatoxin B1 (AFB1). The assay was based on a modified competitive binding format using colloidal gold and polyclonal antibody (Pab) conjugates. The anti-AFB1 Pab was immobilized to a defined detection zone on a porous nitrocellulose membrane and colloidal gold particles were conjugated to AFB1-BSA which served as a detection reagent. The AFB1-containing sample was added to the membrane and allowed to move with AFB1-BSA-coated particles dried on the conjugation pad. The mixture was then passed along the porous membrane by capillary action past the Pab in the detection zone, which captured AFB1 or AFB1-BSA. AFB1 in the sample inhibits binding of AFB1-BSA conjugated gold particles to the Pab and prevents formation of a red color dot. In the absence of AFB1, AFB1-BSA conjugated gold particles bound to the Pab, give a red color within this detection zone. With this method, 10 µg/mL of AFB1 was detected in less than 10 min. The developed AFB1 assay also showed no cross reaction to Ochratoxin A (OTA).