Fatigue of intermittently stimulated quadriceps during imposed cyclical lower leg movements

During prolonged experiments the influence of knee angular velocity, and stimulation parameters (interpulse interval (IPI), duty cycle (DC), number of pulses per cycle (NP)) on fatigue-induced torque\ud decline of paralyzed human quadriceps was studied. Identification of torque-angle and -angular velocity was also performed. The overall loss of maximum torque (MT) and torque-time integral ('lTI) per cycle during sustained intermittent stimulation during isokinetic movement had a typical exponential decay reaching asymptotic values. Larger knee velocities resulted in a significantly faster and relative larger decay of MT and TTI. The rate and relative magnitude of fatigue during concentric contractions are in direct relation\ud to NP. The results may be valuable in the design of optimal control systems for FES which pursue minimization of muscle fatigue

Peningkatan Prestasi Pembelajaran Tema Menyimpulkan Isi Berita Dari Televisi Atau Radio Dengan Metode Contextual Teaching and Learning Pada Siswa Kelas VI Sdn Ringinsari I Kecamatan Kandat Kabupaten Kediri

Melalui pembelajaran contextual teaching learning (CTL) diharapkan peserta didik tidak hanya dapat menulis dan mengembangkan serta menyimpulkan isi dari sebuah berita yang di dengar ataupun dilihat di televisi ataupun radio ataupun media yang lainya, tetapi juga diperlukan kecermatan untuk membuat suatu rangkaian kata yang baik dan sesuai dengan kaidah tata bahasa,dalam penelitian tindakan kelas ini dilakukan melalui 2 siklus pembelajaran.Dari 35 siswa yang tuntas hanya 13 (37%) siswa, dengan rata-rata klasikal 64. Hal ini menunjukkan bahwa pembelajaran Awal perlu adanya perbaikan, sehingga penelitian ini dilanjutkan pada proses perbaikan pembelajaran siklus 1. Prestasi hasil belajar pada perbaikan pembelajaran siklus 1 sudah ada peningkatan, dimana capaian rata-rata klasikal mencapai 70,1.Namun hal tersebut masih belum memuaskan, sebab masih banyak siswa yang mendapat nilai di bawah standart ketuntasan. Dari 35 siswa yang tuntas hanya 15 (42%) siswa, dengan rata-rata klasikal 70,1. Hal ini menunjukkan bahwa perbaikan pembelajaran siklus 1 perlu adanya perbaikan, sehingga penelitian ini dilanjutkan pada proses perbaikan pembelajaran siklus 2. Prestasi hasil belajar siswa telah mengalami Perubahan jauh lebih baik bila dibandingkan dengan pembelajaran sebelumnya. Dimana rata-rata klasikal pada tahap perbaikan pembelajaran 2 mencapai 83,70. Sedangkan banyaknya siswa yang mampu meraih nilai sesuai dengan kriteria ketuntasan berjumlah 35 dari 35 siswa, dengan persentase ketuntasan 100%. Sehingga kegiatan perbaikan pembelajaran yang dilakukan sudah mencapai ketuntasan yang diharapkan. Dengan pembelajaran Metode Contextual Teaching and Learning hasil belajar siswa yang terus meningkat dan dapat dijadikan sebagai salah satu cara guru dalam menerapkan metode pembelajaran di dalam kelas

Motion Cueing for Stall Recovery Training in Commercial Transport Simulators

Starting in 2019, airline pilots will be required to perform full stall recovery training in flight simulators. Historically, training simulators weren't required to provide training at conditions outside their normal flight envelope. Post-stall aircraft models are generally required to be implemented to simulate the aircraft response after the stall point. In addition, motion cues need to adequately represent this response to ensure the skills learned in simulator training are directly usable in real flight. This paper provides and overview of six simulator experiments conducted at NASA Ames Research Center to develop a motion cueing strategies for stall recovery training in commercial transport simulators. One of the experiments verified an enhanced motion cueing strategy for stall recovery training on a level-D-certified full flight simulator. This study showed that the enhanced motion results in lower maximum roll angles in the stall maneuver, lower minimum load factors in the recovery, lower numbers of secondary stick shakers in the stall recovery, and a lower maximum airspeed in the recovery. These results indicate that relatively minor enhancements to the motion logic of heritage commercial transport simulators can significantly improve pilot performance in simulated stall recoveries, and potentially improve stall recovery training

Hydrodynamic modelling of gas-particle flows in riser reactors.

Complex hydrodynamic behavior of circulating fluidized beds makes their scale-up very complicated. In particular, large-scale lateral solids segregation causes a complex two-phase flow pattern which influences significantly their performance. Lateral solids segregation has been attributed to direct collisional interactions between particles as well as to interaction between gas-phase eddies and dispersed particles. However, these phenomena have not been investigated thoroughly. \ud This article discusses an advanced 2-D hydrodynamic model developed for circulating fluidized beds based on the two-fluid concept. Because theory to model the interaction between gas-phase eddies and dispersed particles is not available, turbulence was modeled on a macroscopic scale using a modified Prandtl mixing length model. To model the influence of direct particle-particle collisions the kinetic theory for granular flow was applied based on the Chapman-Enskog theory of dense gases. For model validation purposes, a cold flow circulating fluidized bed was employed in which sand was transported with air as fluidizing agent. The column is equipped with pressure transducers to measure the axial pressure profile and with a reflective optical fiber probe to measure the local solids concentration and axial solids velocity. Theoretically calculated solids concentration and axial solids velocity agree satisfactorily with experiment, especially when one realizes that the model contains no adjustable parameters. In general, however, the model slightly underpredicted the experimentally observed lateral solids segregation and yielded a more peaked velocity profile compared to its experimental counterpar

The influence of voluntary upper body exercise on the performance of stimulated paralysed human quadriceps

In this study the influence of voluntary upper body exercise on the performance of stimulated paralysed human quadriceps was investigated in five subjects with spinal cord lesions in the thoracic spine. The experimental setup consisted of computer-controlled stimulation of the quadriceps using electrodes on the surface of the skin, a dynamometer for isometric or isokinetic loading of the lower leg, and a rowing ergometer for upper body exercise. In all subjects, quadriceps fatigue tests were conducted to study the influence of upper body exercise on knee torque during sustained continuous or intermittent stimulation of quadriceps. The relative asymptotic torque appeared to be significantly higher with the presence of upper body exercise than without. This was consistently found both between trials (starting with or without upper body exercise) as well as within trials, when upper body exercise was started or stopped during the trial. No significant influence of upper body exercise on the time constant of initial torque decline was found

Perbandingan Kinerja Basis Data Relasionaldengan Basis Data Berorientasi-objek Studi Kasus: Aplikasi Jpetstore

Basis Data Berorientasi Objek (BDBO) menggunakan model berorientasi objek untuk penyimpanan data. Selama ini penggunaan BDBO tidak populer disebabkan oleh beberapa standar yang berbeda dalam pemodelan dan perancangan skema data, serta kinerja yang dianggap kurang baik. Padahal dengan pengembangan aplikasi berorientasi objek seyogyanya penggunaan BDBO dapat menurunkan kerumitan dan meningkatkan kualitas kode aplikasi. Penelitian ini bertujuan mengkaji standar penerapan model objek data dan metode perancangan skema data pada BDBO melalui pengukuran kinerja dan kualitas kode dari aplikasi. Penelitian ini mengkaji penerapan model data ODMG 3.0 dan notasi UML pada aplikasi JPetStore dengan menggunakan transformasi Muller untuk perancangan skema data. Aplikasi JPetStore versi MySQL (BDR) dibandingkan kinerjanya dengan versi DB4O (BDBO). Hasil kajian adalah beberapa tambahan pada model ODMG 3.0 dan tambahan notasi UML untuk pemodelan data pada BDBO serta penyesuaian proses transformasi Muller. Kinerja aplikasi versi DB4O secara umum lebih cepat dibandingkan versi MySQL, kecuali dalam membaca data sederhana secara berurut. Kualitas kode aplikasi versi DB4O lebih baik dibandingkan versi MySQL

Control Force Compensation in Ground-Based Flight Simulators

This paper presents the results of a study that investigated if controller force compensations accounting for the inertial force and moment due to the aircraft motion during flight have a significant effect on pilot control behavior and performance. Seven rotorcraft pilots performed a side-step and precision hovering task in light turbulence in the Vertical Motion Simulator. The effects of force compensation were examined for two different simulated rotorcraft: linear and UH-60 dynamics with two different force gradient of the lateral stick control. Four motion configurations were used: large motion, hexapod motion, fixed-base motion, and fixed-base motion with compensation. Control-input variables and task performance such as the time to translate to the designated hover position, station-keeping position errors, and handling qualities ratings were used as measures. Control force compensation enabled pilot control behavior and performance more similar to that under high- or medium-fidelity motion to some extent only. Control force compensation did not improve overall task performance considering both rotorcraft models at the same time. The control force compensation had effects on the linear model with lighter force gradient, but only a minimal effect on pilots? control behavior and task performance for the UH-60 model, which had a higher force gradient. This suggests that the control force compensation has limited benefits for controllers that have higher stiffness

Pemetaan Tingkat Kerawanan Tsunami Di Pantai Parangtritis Dengan Menggunakan Sistem Informasi Geografi

Tsunami is one of the natural events that can not be predicted. The causal of tsunami can be submarine earthquake, submarine volcanic eruptions, or submarine landslide. The mapping of tsunami vulnerability in Parangtritis Beach is an effort of disaster mitigation to minimize the negative impact of tsunami. The research is aimed to map the vulnerability of tsunami disaster in the area of Parangtritis Beach. There are five classes of vulnerability level i.e. very vulnerable class, vulnerable class, slightly vulnerable class, safe class, andvery safe class. The places in Kretek Sub-district which are rated vulnerable (very vulnerable, vulnerable, and slighty vulnerable) is covering the area of 1.334,22 hm2 or 52,93 % of Kretek Sub-district. The places in Kretek Subdistrict which are rated safe is covering the area of 1.186,27 hm2 or 47,06% of Kretek Subdistrict