Eiji Inoue

Impact of aquatic plants on entrainment phenomena based on wind-induced flow in a closed density stratified water area

It has recently been proposed that water purification could be performed using aquatic plants, since they absorb nutrient salts. The behavior of a substance in a closed water area is affected by turbulent flows from wind-induced flow, which is a mechanical disturbance, and convective flow, which is a thermal disturbance. In a closed density stratified water area, wind-induced flow gives rise to the entrainment phenomenon at the density interface. This phenomenon, which is based on mixing between the upper and lower water layers, lowers the density interface and so affects the water quality. We experimentally investigated the effect of aquatic plants on the turbulent flow from a mechanical disturbance in the closed water area. Results indicated that the presence of floating and submerged plants had a significant effect on the scale of the turbulent entrainment, and that the entrainment velocity depended on the overall Richardson number to the power of −3/2.

Simulation for Vertical Dynamic Loading Forces on Track Rollers of the Half-tracked Tractor Based on Nonlinear Voigt's Model

Abstract Experiments to measure the vertical dynamic loading forces acting on the track rollers of a half-tracked tractor were conducted by using strain gauges. In addition, a driving simulation model was constructed to predict the vertical dynamic loading forces acting on the track rollers as the tractor ran on an asphalt road surface. A twodimensional model to evaluate the vibration characteristics of the half-tracked tractor is discussed. It was modified and improved by considering the linear and nonlinear interactions of the rubber crawler with the track roller as well as the rollers location arrangement.

Development of a remote environmental monitoring and control framework for tropical horticulture and verification of its validity under unstable network connection in rural area

Display Omitted Remote monitoring and control framework under unstable network connection.The framework consists of local and global management subsystem.Evaluated on tropical horticulture monitoring and soil moisture content control. This study focuses on the development and evaluation of a remote field environmental monitoring and control framework, implementing a local-global management strategy to overcome the unstable network connection in the rural area. The framework consists of environmental monitoring and control node as the local management subsystem (LMS), and the web data providing and system management as the global management subsystem (GMS) to establish a simple and flexible remote environmental monitoring and control based on a cloud platform. The supporting features are online and offline environmental monitoring, synchronization of system configuration, actuation, and offline management. Two field tests were conducted to verify its performances and functionalities, (1) environmental monitoring on tropical horticulture cultivation in Yogyakarta, Indonesia, and (2) implementation of the monitoring and control for automatic drip irrigation control based on soil moisture content for tomato. As the result of the first test, the developed framework could help to maintain the sustainability of environmental monitoring under unstable network connection over 80% availability of the data with local offline measurement up to 24% of the total entries. From the second test result, the framework could support the real-time monitoring and control of soil moisture content as well as increase the system flexibility in the adjustment of the system configuration remotely. The control system has 0.78% error (E) and 99.2% in-range soil moisture content (L

Development of Actuation Framework for Agricultural Informatization Supporting System

Abstract Agriculture faces many challenges in the production system, such as climate and weather, field conditions, crop types, soils types and conditions, and so on. Farmers consider many aspects to optimize the “on-farm” process by their long-term experiences. Various informatization agricultural supporting systems have been developed using ICT (Information and Communication Technologies) to improve agricultural productivity. Authors have developed the ICT-based agricultural supporting system called the “Agri-eye” in which a field monitoring, crop growth and quality evaluation, work recording, and online data offering and sharing sub-systems were incorporated. On the other hand, an actuation sub-system for controlling and managing agricultural facilities in a greenhouse such as a heater, water pumps, circulation fans, a CO 2 generator, etc. has been introduced. In this study, an actuation framework is developed as a useful method for monitoring and controlling local facilities and machineries. The method can be used for controlling particular device with adjusting parameter from Agri-eye server to meet the cultivation requirement. Furthermore, the validity of the developed framework was verified to monitor and control air temperature in laboratory test box.

A one-dimensional model for water quality simulation in medium- and small-sized rivers

While studying water quality in the Tatara river, we realized that the river has various hydraulic and topographic characteristics when flowing through different regions. Because of these specific characteristics, the application of the existing models for simulation of its water quality may not be appropriate due to limitations in the models themselves. Therefore, we developed a mathematical model that is suitable for short-term simulations of water quality in rivers with characteristics similar to the Tatara river. The main foundation of the model is the one-dimensional transport equation established on the basis of the mass conservation law. To solve this equation numerically, it was discretized by the method of finite-difference approximations, and an algorithm has been programmed in Fortran 90. To verify the model, the Tatara river was chosen as a case study. Water temperature, dissolved oxygen, hydraulic parameters in four typical blocks of the river, and meteorological data of the study area, have been observed and used to test the model. By calibrating the model with different series of data collected from the designated blocks, all results have shown a good fit between simulated data and the observed one. Therefore, the model could be a reliable tool for simulating water quality in medium- and small-sized rivers over a short-term period. This research has also indicated the changing tendencies of water temperature and dissolved oxygen in Tatara river in response to different meteorological patterns over a daily 24-h period. Besides, the model could be improved to simulate other water quality variables, which would be studied further.

Turbulent Flow Characteristics of the Cleaning Wind in Combine Harvester

Abstract The flight of separated straws is thought to affect the cleaning wind of a combine harvester. To comprehend the turbulent flow characteristics of the cleaning wind and its passage through the grains, the cleaning wind velocity is measured by particle image velocimetry and laser Doppler velocimetry. The flow of the cleaning wind is blocked by the grains, and therefore the distribution of wind velocity changes. It is found that the energy loss of the cleaning wind is not a result of turbulent flow. The wall friction and the pressure change observed as a result of the shape and the friction loss in the grains are the main considerations while calculating the energy loss of the cleaning wind in combine harvester.

Collision Vibration Characteristics with Interspace in Knife Driving System of Combine Harvester

Abstract It is necessary to develop a design theory of the knife driving system of combine harvesters in order to derive the control parameters of the balance weights used for vibration reduction. A collision vibration model of the knife driving system that is equipped with a slider-crank mechanism was constructed in order to examine the influence of the interspace that arises at the joint of the drive knife and the end of the link arm. The simulation result revealed that the harmonic frequency components varied with an increase in the width of the interspace although the highest harmonic frequency in the simulation without the interspace was three times the crank wheel rotation frequency. However, the vibration reduction by the balance weight was not dependent on the width of the interspace.

Feasibility Study on Field Monitoring and Work Recording System in Agriculture

Simple field monitoring system for optimizing and improving agricultural production process and management is developed by the built-in mail sender data logger unit with some weather and field monitoring sensors. In this monitoring system, all the monitoring data are once transferred and stored to mail servers. Thereafter the data are transferred periodically to the agricultural information database system. The database system was fully developed using open software such as apache (web server), MySQL, PHP, Java, CMS (Contents Management System) and so on. The stability of the monitoring system was verified using more than 20 monitoring units at four test sites where weather, crop type and farm size are different. On the other hand, work recording system to manage and optimize current production process was also developed and integrated to the developed database system. A list of farming processes and schedules was arranged flexibly by a farmer thorough a web browser. All the process data were entered into the information database by using mobile device and/or PC. The availability and validity of the developed recording system were verified by feasibility studies in the real farming sites.

The impact of floating water plants on wind-induced flow and wind wave in a closed water area

In some closed water bodies, the fluids are generally stratified based on vertical density differences. The causes of density these differences can be categorized as being due to temperature, salt levels, and turbidity. In addition, the dynamics of water environmental substances are induced by wind-induced turbulence, which is based on mechanical disturbances, and convective flow, which is based on thermal disturbances. Wind-induced flow and wind waves are produced when mechanical disturbances act on the water surface. These effects in turn generate a lowering of the density interface and increases in the upper layer density based on mixing between upper- and lower-layer fluids, which is commonly referred to as an entrainment phenomenon. This entrainment phenomenon greatly affects the dynamics of water quality in a closed water body. The production of turbulent energy at the water surface and its transport towards the interface play an important role in the dynamics of water environmental substances. When the surface of a closed water body is partially covered with floating water plants, it is considered that wind waves and wind current based on wind action body affected by the plants to some extent, especially in small reservoirs and creeks, which have less surface area for the wind to acts on. We have previously reported that the value of entrainment velocity decreases as the coverage rate of floating water plants increases. It is considered that the covered water surface cause a reduction in the turbulent energy produced by wind shear. It is therefore important to clarify the effects of floating water plants on the wind-induced flow and wind waves generated by wind shear. Accordingly we experimentally considered the turbulent characteristics of wind-induced flow and wind waves in a closed water body with floating water plants. The results indicate that the energy of wind-induced flow is affected by the existence of floating water plants and that the energy decrease as the covereage rate of floating water plants increases.

Numerical Analysis of the Reaction Force of a Single Rice Stalk undergoing Forced Displacement

In this study, the reaction force of a rice stalk undergoing forced displacement was analysed based on a mechanical model of a crop stalk. Horizontal and vertical reaction forces of a single rice stalk undergoing forced displacement were measured. The horizontal force increased linearly for small curvatures of the rice stalk; after that, force increments decreased with displacement due to large curvature of the stalk. The vertical reaction force had different tendencies, depending on the initial shape of the rice stalk. The main reason for the differences was a directional change in friction, depending on the initial shape. An intrinsic shape function of a rice stalk was proposed. An equation of curvature describing rice stalk bending was derived by considering the curvature due to intrinsic shape, and used for analysis of the reaction force. The analytical results coincided fairly well with measured values, and it was demonstrated that the reaction forces of a single rice stalk according to the initial shape was accurately predicted by numerical calculation.