National Institute of Technology, Toyama College

ABSTRACTAgricultural intensification and land reclamation have transformed natural wetlands into farmland across East Asia, which has been a threat to bird diversity, particularly wetland and grassland specialists. Despite extensive research in warm temperate and tropical rice‐growing regions, bird communities in snow‐rich agricultural wetland landscapes remain poorly studied. Here we present a dataset describing bird assemblages in a heterogeneous agricultural landscape surrounding Lake Kahokugata, located in a snow‐rich region on the Sea of Japan side of central Japan. The area represents a land reclamation zone shaped by decades of wetland conversion. We conducted point‐count surveys across 43 plots in winter and summer (2021 and 2023), yielding 129 replicated observations. The plots encompassed diverse cropland types, including rice paddies, lotus root fields, vegetable fields, pastures, and abandoned lands, representing a mosaic of wet and dry farmland. The dataset includes abundance records of 41 bird species, along with land‐use attributes within a 75 m radius and landscape data on open waterbodies within a 500 m radius. Our data is useful in providing insights into how landscape heterogeneity, cropland composition, and seasonal dynamics influence bird diversity in snowy agricultural wetlands.

In a wide range of industrial fields, the advancement of hydraulic dampers for vibration control has become an important research and development topic. In this paper, we propose a novel internal-flow origami hydraulic damper with nonlinear damping characteristics to overcome the limitations of conventional cylindrical hydraulic dampers with restricted linear strokes. First, the basic structure and design method of the proposed origami hydraulic damper are examined. Subsequently, the flow characteristics of the internal fluid in the origami hydraulic damper are analyzed, and a formula is derived to calculate the damping force acting on the damper. We confirm that the damping force is proportional to the square of the velocity. Furthermore, a verification experimental system using a nonlinear origami hydraulic damper in a mass-spring vibration system was developed. Shaking experiments using actual Fukushima earthquake waves were conducted, and the response acceleration decreased by 63.49%. For further verification, shaking experiments were performed by changing the orifice diameter of the nonlinear origami hydraulic damper, and the average reduction rate of the response acceleration for different orifice diameters was 62.68%. In addition, to verify the vibration control effect under different earthquake waves, we conducted shaking experiments using the same experimental setup and conditions as those used for the El Centro NS and Taft NW earthquake waves. The average reduction rate of the response acceleration for different earthquake waves was 62.22%. Thus, the damping characteristics and effectiveness of the proposed internal-flow origami hydraulic damper were confirmed.

Chất dính thủy tinh lỏng vẫn được sử dụng rộng rãi trong công nghệ đúc mẫu chảy để sản xuất các chi tiết có độ nhẵn bóng bề mặt cao, kích thước chính xác. Tuy nhiên, huyền phù thủy tinh lỏng vẫn còn một số hạn chế, thí dụ, độ thông khí kém, độ bền còn lại cao, dễ bị nứt bề mặt. Bài báo này giới thiệu một phương pháp biến tính thủy tinh lỏng nhằm khắc phục các nhược điểm trên. Chất biến tính nano-SiO₂ được tổng hợp bằng phương pháp sol-gel, với kích thước hạt trung bình là 20 nm. Các mẫu thử gồm nước thủy tinh lỏng được biến tính lần lượt bằng 2,5%, 5,0%, và 7,5% theo khối lượng, sau đó trộn từng mẫu với bột Zircon để đạt được tỉ lệ chất dính/bột là 60:40; 57,5:42,5; 55:45, chất phụ gia là Carboxymethyl cellulose. Các đặc tính của sơn khuôn mẫu chảy được đánh giá bao gồm độ nhớt, khả năng bám dính và độ thông khí. Thông số tối ưu đạt được là thủy tinh lỏng có mô-đun 2,9, được biến tính bởi 2,5% nano-SiO₂, sử dụng 0,5% chất phụ gia. Theo lý thuyết về đúc mẫu chảy, sản phẩm được đúc trong buồng chân không, sử dụng bơm để đạt được môi trường áp suất thấp. Trong nghiên cứu này, áp suất được áp dụng là 0,4 kg/cm² có thể cải thiện chất lượng vật đúc.

This work proposes a newly developed investigation robot operating in two modes: (1) autonomous and (2) manual mode. Designed to operate in hazardous environments such as confined, debris-filled, and dark spaces, the robot can autonomously navigate, collect critical data, and assess structural conditions. Upon completing its mission, the robot returns to its initial position, supporting the operator by improving operational efficiency and safety. The main implementation is the investigation of underfloor in Japanese houses. The robot navigates and updates its location on a predefined map. The robot recognizes possible cracks in the concrete blocks. Autonomy and remote control of the robot contribute to more efficient, timely, and safer underfloor investigation.

This paper describes the development of a remotely operated robot for internal exploration and sample debris collection in the primary containment vessel (PCV) for the purpose of participating in the 9th Decommissioning Creative Robot Contest. The developed robot has a crawler-based moving mechanism with a four-link mechanism and a sample debris collection mechanism at the front. The robot is remotely operated via wired LAN cable communication, and is equipped with USB cameras in the front and rear as well as an omni-directional camera to ensure a wide field of view, which is necessary for tele-operation. Furthermore, it has a cable drum for deploying LAN cables, providing excellent cable management during transportation. After building a test field and conducting a trial run with the robot, The robot was entered in the main Robocon competition. The results confirmed that the robot performed as designed and also revealed unexpected issues.

In recent years, significant attention has been given to the physical properties of low-dimensional materials. Carbon nanotubes (CNTs), a prime example of such materials, are emerging as a promising next-generation candidate material for sensor components, including yoctogram (10−24 g) measurement devices and antennas capable of handling large-scale digital data. CNTs exhibit a variety of atomic arrangements due to their chirality. However, even 30 years after their discovery, controlling the chirality of CNTs remains challenging, and the specifics of their physical properties still require clarification. Understanding the vibration characteristics of carbon nanotubes (CNTs) is crucial for designing nanoscale structures and devices. In this study, we analyzed the effects of tube diameter, push ratio, and length of CNTs on vibration using molecular dynamics simulation. This method allows for the modeling of ideal geometric structures at the atomic level and the tracking of their behavior. The findings are as follows: For armchair carbon nanotubes, the resonance frequency decreased with an increase in the length of the CNTs. It was observed that the thermal energy generated during vibration tends to decrease with an increase in tube diameter. The full width at half maximum increases with an increase in the push ratio.

Exposure of water to ionizing radiation induces OH radical formation. Within cellular environments, the presence of OH radicals can stimulate the abstraction of hydrogen atoms from the sugar backbone of DNA. Subsequent damage to DNA structures leads to various diseases. Multiple studies have elucidated this phenomenon, especially computational studies examining the differences in the degree of abstraction between the sugar hydrogens (H1′, H2′, H2″, H3′, H4′, H5′, and H5″). However, the details of this phenomenon have not yet been clarified. It is rare for OH radicals to approach DNA within the simulation time, making it difficult to adequately sample the configurations in which OH radicals immediately precede the abstraction of the hydrogen atoms. To address this problem, we performed molecular dynamics simulation to calculate the relative accessibility by putting a potential on nucleotides and OH radicals. As a result, we found that the accessibility of OH radicals to each hydrogen atom differs from that of water molecules as solvents. A more detailed accessibility analysis revealed that the angle of the OH radicals approaching the hydrogen atoms of ribose and the energy barrier for abstracting the hydrogen atoms can be considered to improve the correspondence with the experimental data. Moreover, we found that the behavior of water molecules and OH radicals toward accessibility to DNA differs significantly and showed that the factors are related to the physicochemical properties of water molecules and OH radicals, as well as the structure of DNA.

This paper proposes a page-turning strategy using an assistive robot that has a low-degree-of-freedom robotic hand. The robotic hand is based on human object handling characteristics, which significantly reduces the number of fingers and joints required to handle various objects. The robotic hand has right and left planar fingers that can transform their shape to handle various objects. To turn a page, the robot uses the planar fingers to push the surface of the page and then rotates the fingers. The design concept, mechanism, sensor system, strategy for page turning, and control system of the robotic hand are presented. The experimental results show that the robot can turn pages using the proposed method; however, it sometimes failed to turn the page when the robotic hand height was too low and too close to the book because the rotation of the fingers was stopped by the book. When the hand detects excessive force during page turning, the control system changes the shape of the fingers and releases the force from the book. The experimental results show the effectiveness of the control system.