100 essential questions for the future of agriculture

Publication history: Accepted - 8 March 2023; Published online - 11 April 2023.The world is at a crossroad when it comes to agriculture. The global population is growing, and the demand for food is increasing, putting a strain on our agricultural resources and practices. To address this challenge, innovative, sustainable, and inclusive approaches to agriculture are urgently required. In this paper, we launched a call for Essential Questions for the Future of Agriculture and identified a priority list of 100 questions. We focus on 10 primary themes: transforming agri-food systems, enhancing resilience of agriculture to climate change, mitigating climate change through agriculture, exploring resources and technologies for breeding, advancing cultivation methods, sustaining healthy agroecosystems, enabling smart and controlled-environment agriculture for food security, promoting health and nutrition-driven agriculture, exploring economic opportunities and addressing social challenges, and integrating one health and modern agriculture. We emphasise the critical importance of interdisciplinary and multidisciplinary research that integrates both basic and applied sciences and bridges the gaps among various stakeholders for achieving sustainable agriculture. Key points Growing demand and resource limitations pose a critical challenge for agriculture, necessitating innovative and sustainable approaches. The paper identifies 100 priority questions for the future of agriculture, indicating current and future research directions. Sustainable agriculture depends on interdisciplinary and multidisciplinary research that harmonises basic and applied sciences and fosters collaboration among different stakeholders

Experimental study on shear deformation of reinforced concrete beams using digital image correlation

This paper presents an experimental program aimed at providing reliable and comprehensive experimental data for assessing the available models of predicting the shear deformation of diagonally-cracked reinforced concrete (RC) beams. The non-contact measuring technique, Digital Image Correlation (DIC), was used to monitor the full-field displacement and strain in the shear span of five RC beams with thin webs. Virtual measuring grids were created to measure the mean shear strain and other critical deformation results which reflects the mechanism of shear deformation after shear cracking (i.e. the principal compressive strain angle, the principal compressive strain, the mid-depth longitudinal strain and the mean vertical strain). The experimental mean shear strain and other critical deformation results were compared with the predictions with several available models. The comparison indicates the available models fail to reproduce the principal compressive strain angle,the mid-depth longitudinal strain and the mean vertical strain which constitute the key parameters in estimating the shear deformation after shear cracking. As a result, significant discrepancies in the shear deformation of the beams tested in this paper are observed between the experimental and calculated results. It is also found that the predicted shear deformation of a number of beam specimens tested by other researchers with the available models deviates considerably from the experimental results. In general, the existing models are not capable of providing accurate predictions of the shear deformation of RC beams and further investigation into this topic is needed.submittedVersio

Theoretical and Experimental Study of Effective Shear Stiffness of Reinforced ECC Columns

Abstract Engineered cementitious composites (ECC) possesses characteristics that make it suitable in the zones of high shear and ductility demand of structural elements; however, there is a lack of an adequate model to predict its shear stiffness. A theoretical model for the effective shear stiffness of reinforced ECC (RECC) columns is proposed on the basis of the truss-arch model, with the consideration of the unique property of ECC material. A total of six column specimens subjected to cyclic reverse loading are conducted, and the main test variables include the shear span-to-depth ratio, the transverse reinforcement ratio and the axial load ratio. Results show that the shear contribution to the total deflection in the diagonally cracked RECC beam is significant, and the proposed theoretical model can predict the shear deformation with reasonable accuracy

Stability and Gait Planning of 3-UPU Hexapod Walking Robot

The paper presents an innovative hexapod walking robot built with 3-UPU parallel mechanism. In the robot, the parallel mechanism is used as both an actuator to generate walking and also a connecting body to connect two groups of three legs, thus enabling the robot to walk with simple gait by very few motors. In this paper, forward and inverse kinematics solutions are obtained. The workspace of the parallel mechanism is analyzed using limit boundary search method. The walking stability of the robot is analyzed, which yields the robot’s maximum step length. The gait planning of the hexapod walking robot is studied for walking on both flat and uneven terrains. The new robot, combining the advantages of parallel robot and walking robot, has a large carrying capacity, strong passing ability, flexible turning ability, and simple gait control for its deployment for uneven terrains

Seismic Performance Analysis of RC Frames with ECC Short Columns Based on the IDA Method

Engineered cementitious composite (ECC) is a high-performance composite material with greater shear deformation and shear strength than normal concrete, which has been proposed for use as a shear component in structures. This study modeled three frames, a pure reinforced concrete (RC) frame, an RC frame with concrete short columns and an RC frame with ECC short columns, using the incremental dynamic analysis (IDA) method to evaluate the contribution of ECC to the structural performance. A modified IMK model was applied to model the entire history of the mechanical behaviors of the short columns. The IDA curves, interfloor displacement angle distribution and limit state of the vertex displacement of the frames were analyzed to investigate the seismic responses of the frames. The model analysis results showed that an RC frame with short columns would form a weak layer on the floor where the short columns were located, which greatly weakened the seismic performance of the structure. ECC was certified to be effective in improving the shear formation of the short columns in the frames. The frame with ECC short columns improved the seismic performance of the structure to a certain extent relative to the frame with RC short columns. The deformation capacity of the frame with ECC short columns was close to that of the pure RC frame at the collapse level

Seismic Performance Analysis of RC Frames with ECC Short Columns Based on the IDA Method

Engineered cementitious composite (ECC) is a high-performance composite material with greater shear deformation and shear strength than normal concrete, which has been proposed for use as a shear component in structures. This study modeled three frames, a pure reinforced concrete (RC) frame, an RC frame with concrete short columns and an RC frame with ECC short columns, using the incremental dynamic analysis (IDA) method to evaluate the contribution of ECC to the structural performance. A modified IMK model was applied to model the entire history of the mechanical behaviors of the short columns. The IDA curves, interfloor displacement angle distribution and limit state of the vertex displacement of the frames were analyzed to investigate the seismic responses of the frames. The model analysis results showed that an RC frame with short columns would form a weak layer on the floor where the short columns were located, which greatly weakened the seismic performance of the structure. ECC was certified to be effective in improving the shear formation of the short columns in the frames. The frame with ECC short columns improved the seismic performance of the structure to a certain extent relative to the frame with RC short columns. The deformation capacity of the frame with ECC short columns was close to that of the pure RC frame at the collapse level

Wear behavior of (TiB2-TiC)-Ni/TiAl/Ti gradient materials prepared by the FAPAS process

(TiB2-TiC)-Ni/TiAl/Ti functionally gradient materials were prepared by field-activated pressure-assisted synthesis processes. (TiB 2-TiC)-Ni composite ceramic, the top layer of the functional gradient materials, was prepared in situ by the combustion synthesis process using Ti and B4C powders as raw materials. Scanning electron microscope (SEM) images of the ceramic layer revealed that the TiB2 and TiC particles in the composite were fine and homogeneously dispersed in the Ni matrix. The friction and wear properties of the (TiB2-TiC)-Ni ceramic were evaluated by sliding against a GCr15 disk at temperatures from ambient up to 400 C. The experimental results showed that the friction coefficient of the (TiB2-TiC)-Ni ceramic decreased with the increasing testing temperature, load, and sliding speed. However, the loss rate decreased at higher temperature and increased at higher load and higher sliding speed. The wear mechanisms of (TiB2-TiC)-Ni ceramic mainly depend upon thermal oxidation at higher temperature, load, and sliding speed. The worn topography and phase component of the worn surfaces were analyzed using SEM, energy dispersive spectroscopy, and X-ray diffraction. The oxide films of Fe 2O3, TiO2, and B2O3 formed during the friction process play an important role in lubrication, which results in a smaller friction coefficient. 2012 Springer Science+Business Media New York