Compaction behavior, mechanical properties, and moisture resistance of torrefied and non-torrefied biomass pellets

Biomass properties have a potential to be improved by torrefaction, a thermal pretreatment process that removes hemicellulose. The intent in using torrefaction for biomass is to increase the carbon content and calorific value, as well as reduce the hydrophilic nature of woody-biomass. To facilitate the handling and use of torrefied biomass, densification (e.g. pelletizing) is used to compact it into standard uniform shape pellets with high density and mechanical strength. In this thesis, torrefaction as pretreatment, as well as moisture content and particle size of raw biomass materials before pelletizing were studied as parameters that may affect the biomass pellet quality including: compaction behavior, gross heating value, hardness, and moisture resistance. Woody biomass red oak (Quercus rubra), and two species of grass-type biomass switchgrass (Panicum virgatum), and miscanthus (Miscanthus giganteus) were used in the experiment. Results of this research indicated that torrefied biomass required 50% ~ 200% more pelletization energy than non-torrefied biomass. Additionally, in general, the hardness of torrefied biomass pellets was lower than non-torrefied pellets. However, it was found that the moisture resistance of the torrefied biomass pellets was higher than the non-torrefied pellets. The moisture content and particle size also showed some relatively small effects on the biomass pellet properties, but their influence varied from species to species, and even between pretreatments within one species. Therefore, based on the results of this research, the better moisture content and particle size for pellet production was specific to each type of pretreatment and species

Chemical synthesis and characterization of zinc borohydride

AbstractMetal borohydrides have received increasing research interests on account of their high hydrogen storage capacities. In this paper, zinc borohydride Zn(BH4)2 was synthesized using NaBH4 and ZnCl2 in THF under room temperature for 72h, and the crystallographic constitution of the synthesized products were analyzed by XRD. The results showed that the major phase of the products was NaCl, alternatively, NaBH4 or ZnCl2 disappeared. This concluded the formation of Zn(BH4)2. Moreover, both experiment phenomena and fired products further confirmed the synthesis of Zn(BH4)2, which a XRD pattern of Zinc borohydride was obtained

BEST: A Real-time Tracking Method for Scout Robot

Abstract -We propose a BEST (Background subtraction and Enhanced camShift Tracking) method for a scout robot tracking a moving object in real time. A modified back subtraction method based on time axis is used to segment the moving object in a complicated environment. The centroid and area are chosen as the feature to judge target. We proposed a novel method that combines Camshift, AWS (Adaptive Window Selecting method) and Kalman predicting algorithm together to track the detected object. Experiments based on a DSP image processing system in a scout robot indicate the feasibility and robustness of our method

An Opposite-Bending-and-Extension Soft Robotic Manipulator for Delicate Grasping in Shallow Water

Collecting seafood animals (such as sea cucumbers, sea echini, scallops, etc.) cultivated in shallow water (water depth: ~30 m) is a profitable and an emerging field that requires robotics for replacing human divers. Soft robotics have several promising features (e.g., safe contact with the objects, lightweight, etc.) for performing such a task. In this paper, we implement a soft manipulator with an opposite-bending-and-extension structure. A simple and rapid inverse kinematics method is proposed to control the spatial location and trajectory of the underwater soft manipulator's end effector. We introduce the actuation hardware of the prototype, and then characterize the trajectory and workspace. We find that the prototype can well track fundamental trajectories such as a line and an arc. Finally, we construct a small underwater robot and demonstrate that the underwater soft manipulator successfully collects multiple irregular shaped seafood animals of different sizes and stiffness at the bottom of the natural oceanic environment (water depth: ~10 m)

1,4-アンヒドロエリスリトールの1,4-ブタンジオールへの選択的変換のための固体レニウム触媒の開発

Tohoku University冨重　圭一課

Analysis and Experimental Kinematics of a Skid-Steering Wheeled Robot Based on a Laser Scanner Sensor

Skid-steering mobile robots are widely used because of their simple mechanism and robustness. However, due to the complex wheel-ground interactions and the kinematic constraints, it is a challenge to understand the kinematics and dynamics of such a robotic platform. In this paper, we develop an analysis and experimental kinematic scheme for a skid-steering wheeled vehicle based-on a laser scanner sensor. The kinematics model is established based on the boundedness of the instantaneous centers of rotation (ICR) of treads on the 2D motion plane. The kinematic parameters (the ICR coefficient , the path curvature variable and robot speed ), including the effect of vehicle dynamics, are introduced to describe the kinematics model. Then, an exact but costly dynamic model is used and the simulation of this model’s stationary response for the vehicle shows a qualitative relationship for the specified parameters and . Moreover, the parameters of the kinematic model are determined based-on a laser scanner localization experimental analysis method with a skid-steering robotic platform, Pioneer P3-AT. The relationship between the ICR coefficient and two physical factors is studied, i.e., the radius of the path curvature and the robot speed . An empirical function-based relationship between the ICR coefficient of the robot and the path parameters is derived. To validate the obtained results, it is empirically demonstrated that the proposed kinematics model significantly improves the dead-reckoning performance of this skid–steering robot