Engineering in Agriculture, Environment and Food最新文献

Experiments were conducted to extend the shelf-life of tomato using diffusion channel system. Diffusion channels of different combination in length (60, 120, 180, 240 mm) and diameter (3, 6, 9, 12 mm) were installed in the storage chambers of 2L capacity. Tomato samples (800 ± 15 g) at breaker stage were taken in the chambers and stored at 10 °C, 20 °C and 30 °C. Gas concentrations in the chambers were measured periodically untill the end of storage period. O₂ concentration decreased and CO₂ concentration increased with increase in channel length and become more distinct as the diameter increased. These channels were maintained the O₂ concentration in the ranges between 7.2% and 15.5% and CO₂ was 5.2% and 16.3% in the storage chambers. Respiration rate (RR) of tomato decreased with increase in channel length and increased with diameter. The RR of 1.95–8.36, 2.52 to 11.43 and 4.21–14.32 mg O₂/kg h was sustained at 10 °C, 20 °C and 30 °C respectively irrespective of channel length and diameter. Temperature, channel length and diameter had a significant (P ≤ 0.05) effect on visual quality index, firmness, ascorbic acid and lycopene and no significant difference on titratable acidity, total soluble solids and total sugars. The colour change was directly related to lycopene formation. Tomato was stored for 40 days at 10 °C, 32 days at 20 °C and 23 days at 30 °C under diffusion channel combination of length 180 mm and diameter 9 mm with good colour, texture, fresh appearance, retained nutritional values and good marketability conditions.

It is of great practical significance to evaluate the development level of water-saving irrigation objectively and rationally for promoting the utilization of water resources and the development of water-saving irrigation. On the premise of analyzing the influencing factors of water-saving irrigation comprehensively, this paper establishes the index of water-saving irrigation technology development level, determines the index weight, establishes the fuzzy comprehensive evaluation model, and carries out the multi-level, multi-index and multi-factor comprehensive evaluation on the development level of water-saving irrigation in Sichuan Province and various cities and states. The results show that the comprehensive evaluation results of the regional water-saving irrigation development level in Sichuan Province are in a poor level. Under the circumstances of taking reasonable measures, Sichuan Province has a great potential to develop water-saving irrigation.

Embryonic movements, body and cardiac activity, are important physiological phenomena for chick embryo development. Currently, there is no complete non-invasive method for simultaneously quantifying chick embryonic body motility and cardiac rhythm during incubation. This study investigates the use of a near infrared sensor to simultaneously monitor embryonic body and cardiac movements. Light brown chicken eggs (ROSS 308) were incubated for chick embryos activity signals measurement from day 6 to 19. Signal features (peak frequencies and signal energy) of chick embryo periodical activity were extracted to quantify both body and cardiac movements using fast Fourier transform and numerical integration. Two types of body movement were found throughout the whole incubation period. During the early stage of incubation, the movement was periodic; with the pattern differing between embryos. In the mid to late stages of incubation, movements were irregular and had a lower frequency compared to the periodic motion. Heart rates throughout the incubation period varied from 3.8 to 4.8 Hz, while heart beat strength sharply increased during incubation, peaking at day 13 to 14, and then subsequently subsiding. These results indicate that near infrared sensing, combined with signal processing, has the potential to monitor embryo motility and cardiac rhythm that could be used in developmental physiology, cardiovascular medicine and precision poultry production systems.

A high precision compact digital instrumentation system was developed to display, collect, and store desirable tractor performance parameters. The system was designed based on the technical capabilities of human machine interface (HMI) technology. A touch screen user friendly HMI-assisted data acquisition unit was developed to control different procedures of the system for continuous measurement of the tractor performance parameters (driving wheel slip, forward speed, fuel consumption, working depth, and required draft force or drawbar pull of implement) with data collection rate of 90 Hz. Commercial transducers used to develop the system were calibrated for desired measurements. The system was mounted on an agricultural diesel tractor (MF-399) and assessed under static and dynamic conditions. Results of calibration trials indicated a high correlation between actual and measured variables. Maximum errors of less than 5% for stationary assessment of the instrumented tractor in two-wheel drive (2WD) and four-wheel drive (4WD) modes proved an acceptable accuracy of the system. Satisfactory operational efficiency of the system under dynamic field conditions resulted in quick response to small changes of the tractor performance parameters. The system is flexible enough to be easily integrated on any 2WD or 4WD tractor. Practically, the system would be very useful for experimental practices, educational and research studies.

Tomato greenhouse growers need information about yield and harvesting time as a majority of working time to improve a yield, cultivating technique, and management of labor. We developed a tomato yield and harvesting time monitoring system for selective hand harvesting of fresh tomato. The monitoring system consists of an electronic balance, a handheld type barcode scanner, a microprocessor, and cart. Each barcode was set on each tomato plant. The monitoring system can measure and record harvested fruit weight and harvesting time, and save to micro SD card. The yield and harvesting time map were constructed using a spreadsheet software. We conducted a harvesting experiment to investigate monitoring data for 7 months, using 3 varieties. The developed monitoring system could be used in greenhouse environment without any trouble and any disturbance of harvesting work for all experimental term. By using monitoring system, we could get yield map, harvesting time map, and effect of greenhouse climate on yield and harvesting time. It is found that spatial deviation of the total harvested fruit's weight of DR03-103 was the highest. The results showed that in harvesting of fruits of DR03-103, more labor is needed and deviation of harvesting labor is higher. The result of investigation of effect of greenhouse climate and yield indicated that when greenhouse inside temperature increased, the number of harvested fruit and harvesting time is increasing from winter to spring. It was considered it was possible for growers to use yield and harvesting time information by using monitoring system.

Total Mixed Ration (TMR), a system used in combining materials into feed for animals in the right proportion is a complex process especially when by-products are utilized. This involves several steps and unit machines. The current study focused on modeling a fermentation and storage system utilizing by-products for TMR feed production using the Arena V15 simulation program. Process time, operation rate, and bottleneck phenomenon were analyzed. The optimal capacities of unit machines were estimated using Opt-quest, an extension of the simulation program. Results showed the optimal operation rate of the mixer was 99% at 8.5 ton/h capacity and that of the steam sterilizer was 93% at 17.6 ton/h capacity. Moisture regulator was 89% at 7.0 ton/h capacity, while those of the vehicle loader and packaging device were 83.3 and 100% at 12.8 and 2.67 ton/h respectively. A field trial to verify the simulated results was conducted at Hwaseong Dairy Corporation. It shows mean square error and standard deviation between the simulated results and the field trial were within 5% range indicating a significant relationship. This work developed a livestock feed fermentation and storage model for cattle at an optimal performance.

Color and shrinkage are two main quality attributes of dried banana. In this study, a hot air dryer equipped with a computer vision system (CVS) was employed for online monitoring of quality changes of banana during drying. Banana slices were dried at temperatures of 80, 90 and 100 °C and air velocities of 1.0 and 1.5 m/s. Drying took place entirely in the falling rate period. The results showed that the system could successfully measure and monitor the color and shrinkage evolutions of banana during drying. Air temperature had significant effect on drying time. For all temperatures, drying followed by decrease of the lightness (L*) and increase in the redness (a*) of banana samples but with no clear tendency of the yellowness (b*). It was found the total color difference (ΔE*) has a direct relation with drying temperature. Shrinkage showed almost a linear correlation with moisture ratio. Drying at higher temperatures led to more color changes but less shrinkage. Air velocity in the studied range had no significant effect on both color change and sample shrinkage.

Radio frequency (RF) selective heating, a novel method to control insect pests in the stored-grains, has many advantages over the existing methods that use pesticides, fumigants, heat, cold, and mechanical pressure. However, there are many variables that can affect the effectiveness of RF selective heating. The finite element method based COMSOL Multiphysics software was used to simulate the selective heating of rusty grain beetle (Cryptolestes ferrungineus, S) in the bulk stored-wheat at 12, 15, and 18% moisture content. The multi-physics – the electric model, and the non-isothermal fluid flow/heat transfer model were coupled, and the transient electrical and the thermal properties of the insect and wheat were used. Only one quadrant of the RF system including the sample was simulated because of the geometric symmetry in the system. The differences between the experimental and the simulated temperatures for the bulk wheat at MC of 12, 15, and 18% were not more than 13.3, 10.2 and 18.1% respectively. The temperature of the insect was 14.1 °C (maximum) higher than the temperature of the host grain. Therefore, there is a potential of this environmentally friendly method in controlling the insect pests in the stored-grains. The non-uniform heating of the samples was observed, and some recommendations to improve the heating uniformity are presented.

Computer-aided estimation of mass for irregularly-shaped fruits is a constructive advancement towards improved post-harvest technologies. In image processing of unsymmetrical and varying samples, object recognition and feature extraction are challenging tasks. This paper presents a developed algorithms that transform images of the mango cultivar ‘Nam Dokmai to simplify subsequent object recognition tasks, and extracted features, like length, width, thickness, and area further used as inputs in an artificial neural network (ANN) model to estimate the fruit mass. Seven different approaches are presented and discussed in this paper explaining the application of specific algorithms to obtain the fruit dimensions and to estimate the fruit mass. The performances of the different image processing approaches were evaluated. Overall, it can be stated that all the treatments gave satisfactory results with highest success rates of 97% and highest coefficient of efficiencies of 0.99 using two input parameters (area and thickness) or three input parameters (length, width, and thickness).