The motion of the ball thrown by a pitcher is influenced by three forces: gravity, drag force due to air resistance, and lift force which deflects a ball vertically or laterally due to ball spin. The lift force acting on the ball increases with spin rate and movement speed when the spin axis of the ball is orthogonal to the direction of ball movement. Among individual pitchers there were great ...

During RoboCup'99 in Stockholm, we arranged the rst RoboCup Jr. Here, the aim was to allow children to get hands-on experience with robotics, and for this purpose we set up a LEGO Mindstorms robot soccer game for children. We developed the user-guided behavior-based approach in order to allow non-expert users to develop their own robots in an easy and fast manner. Indeed, using this approach, c...

Since conventional crank-driven compressor had many difficulties to increase efficiency due to mechanical loss, new kind of compressor has been paid much of attention by the compressor manufacturers. The free piston compressor mechanism has been one of those kinds. The compressor manufacturers developed an energy efficient free piston linear resonance compressor for a household refrigerator. In...

This paper investigates the applicability to sperm whales of the theory of sound radiating from a piston. The theory is applied to a physical model and to a series of sperm whale clicks. Results show that wave forms of off-axis signals can be reproduced by convolving an on-axis signal with the spatial impulse response of a piston. The angle of a recorded click can be estimated as the angle prod...

Abstract Leather industries cause soil pollution in terms of leather wastes. Chrome-containing wastes (CCLW) also various types pollutions such as air and pollution. The utilization CCLW the development aluminum-based composite is emerging area synthesis materials. In this study, chromium(Cr) form collagen powder was extracted from CCLW. Extracted ball milled with alumina particles for 12.5, 25...

Background. A field study conducted by researchers found the balls used by visual impairment students at school basically used the sound by a small bell inside the ball. However, the sound emitted from the ball is very limited, the ball will sound when it is moved. This makes it difficult for students with visual impairments to find a missing ball that not emitted makes a sound. Objectives. A ...

objective: children with autism have sitting and on-task behavior problems in class. therefore, the effects of three alternative classroom-seating devices such as regular classroom chairs, therapy balls, and air cushions were examined on students’ classroom behavior. material and method: fifteen autistic students participated in this a-b-a-c multiple treatments, semi-experimental study. student...

Background: Our research aimed to compare the biaxial flexural strength of glass ceramic and two different monolithic zirconias after aging, examine fracture surfaces with scanning electron microscopy (SEM) perform elemental analysis energy dispersive spectroscopy (EDS). Methods: Two types CAD/CAM materials (Katana UTML Prettau Anterior) a lithium disilicate material (IPS emax Press) were selec...

The National Institute of Standards and Technology (NIST) has performed calibrations of gas flowmeters using piston and bell provers for three decades. Most of the meters calibrated have been either critical flow nozzles or laminar flowmeters since these meter types are generally chosen as the working standards or transfer standards by other flow calibration laboratories. Often the same meters ...