Electrical Resistivity of Fly Ash Blended Cement Paste at Hardening Stage

In this study, the effects of fly ash on the electrical resistivity of hardening (setting) cement paste were investigated. Different combinations of water/binder ratio and binder dosage levels were prepared for the mixtures. The fly ash was used in the mixtures by replacing the cement in ratio of 0 %, 10 %, 20 % and 30 % by weight. The measurements were done at room temperature. The relation between electrical resistivity and hydration time with and without electric current application was investigated. The results obtained indicate the influence of fly ash content and water to binder ratio on the electrical resistivity of all the pastes under investigation. As a result, electric current application can be used on the cement paste with high volume fly ash in order to accelerate curing period

Investıgatıon of Concrete Component and Sıze Effect on Electrıcal Curıng Method

In this study, the effect of concrete’s component and size on electrical curing method is investigated. To examine the effect of dosage, 250, 300, 350 and 400 dosage and 10 x 10 x 35 cm sized concretes are produced. 0, 40, 60, 80 and 100 V stress intensity are respectively applied on produced concretes at stable frequency by AC power supply. Electrical current with different frequencies are applied on some series at stable frequency stress intensity. Concretes which have different water/cement ratios are produced. It has been researched if accelerated cure can be done on concrete by comparing setting time, porosity, water absorption, compressive strength, etc. of concretes which have current application with the ones which don’t have current application. DC and AC current application on concrete can be made in terms of accelerated cure. Because of DC current’s polarization effect, AC power supply is used in the experiments. Consequently, accelerated cure can be done by applying AC current without having any compressive strength decline under certain stress intensity. Through the application of 100 V stress intensity to the 250, 300, 350 and 400 dosage concretes, their final setting times are shortened 510, 380, 410 and 500 minutes, respectively when they are compared to the same dosage reference concretes. Scanning Electron Microscope (SEM) views of 300 dosage concretes are investigated and it is determined that hydration reactions accelerate as stress intensity increases from 0 V to 100 V.Bu araştırmada, beton bileşenlerinin ve boyutunun elektriksel kür yöntemine etkisi araştırılmıştır. Dozaj etkisini incelemek için 250, 300, 350 ve 400 dozajlı 10 x 10 x 35 cm boyutunda betonlar üretilmiştir. Üretilen betonların üzerine sabit frekans şiddetinde AC güç kaynağından sırasıyla 0, 40, 60, 80 ve 100 V gerilim uygulanmıştır. Bazı seriler üzerine sabit gerilim şiddetinde farklı frekanslarda elektrik akımı uygulanmıştır. Farklı su/çimento oranına sahip betonlar üretilmiştir. Gerilim uygulanan ve gerilim uygulanmayan numunelerin priz süreleri, poroziteleri, su emme oranları, basınç dayanımları vb. karşılaştırmalar yapılarak betonda hızlandırılmış kür yapılıp yapılamayacağı araştırılmıştır. Hızlandırılmış kür açısından DC ve AC akım uygulanabilmektedir. Literatür araştırması neticesinde DC akımın polarizasyon (kutuplaşma) etkisinden dolayı deneylerde AC güç kaynağı kullanılmıştır. Sonuç olarak beton üzerine belirli gerilim şiddeti altında AC gerilim uygulanarak basınç dayanım kaybı yaşanmadan hızlandırılmış kür yapılabilir. 250, 300, 350 ve 400 dozajlı betonlara 100 V AC gerilim uygulandığında şahit numunelerine göre priz sona erme süreleri 510, 380, 410 ve 500 dakika kısalmıştır. 300 Dozajlı betonlarda SEM incelemesi yapılmış olup gerilim şiddetinin 0’ dan 100 V’a arttırılmasıyla hidratasyon reaksiyonlarının hızlandığı belirlenmiştir

Investıgatıon of Concrete Component and Sıze Effect on Electrıcal Curıng Method

In this study, the effect of concrete’s component and size on electrical curing method is investigated. To examine the effect of dosage, 250, 300, 350 and 400 dosage and 10 x 10 x 35 cm sized concretes are produced. 0, 40, 60, 80 and 100 V stress intensity are respectively applied on produced concretes at stable frequency by AC power supply. Electrical current with different frequencies are applied on some series at stable frequency stress intensity. Concretes which have different water/cement ratios are produced. It has been researched if accelerated cure can be done on concrete by comparing setting time, porosity, water absorption, compressive strength, etc. of concretes which have current application with the ones which don’t have current application. DC and AC current application on concrete can be made in terms of accelerated cure. Because of DC current’s polarization effect, AC power supply is used in the experiments. Consequently, accelerated cure can be done by applying AC current without having any compressive strength decline under certain stress intensity. Through the application of 100 V stress intensity to the 250, 300, 350 and 400 dosage concretes, their final setting times are shortened 510, 380, 410 and 500 minutes, respectively when they are compared to the same dosage reference concretes. Scanning Electron Microscope (SEM) views of 300 dosage concretes are investigated and it is determined that hydration reactions accelerate as stress intensity increases from 0 V to 100 V.Bu araştırmada, beton bileşenlerinin ve boyutunun elektriksel kür yöntemine etkisi araştırılmıştır. Dozaj etkisini incelemek için 250, 300, 350 ve 400 dozajlı 10 x 10 x 35 cm boyutunda betonlar üretilmiştir. Üretilen betonların üzerine sabit frekans şiddetinde AC güç kaynağından sırasıyla 0, 40, 60, 80 ve 100 V gerilim uygulanmıştır. Bazı seriler üzerine sabit gerilim şiddetinde farklı frekanslarda elektrik akımı uygulanmıştır. Farklı su/çimento oranına sahip betonlar üretilmiştir. Gerilim uygulanan ve gerilim uygulanmayan numunelerin priz süreleri, poroziteleri, su emme oranları, basınç dayanımları vb. karşılaştırmalar yapılarak betonda hızlandırılmış kür yapılıp yapılamayacağı araştırılmıştır. Hızlandırılmış kür açısından DC ve AC akım uygulanabilmektedir. Literatür araştırması neticesinde DC akımın polarizasyon (kutuplaşma) etkisinden dolayı deneylerde AC güç kaynağı kullanılmıştır. Sonuç olarak beton üzerine belirli gerilim şiddeti altında AC gerilim uygulanarak basınç dayanım kaybı yaşanmadan hızlandırılmış kür yapılabilir. 250, 300, 350 ve 400 dozajlı betonlara 100 V AC gerilim uygulandığında şahit numunelerine göre priz sona erme süreleri 510, 380, 410 ve 500 dakika kısalmıştır. 300 Dozajlı betonlarda SEM incelemesi yapılmış olup gerilim şiddetinin 0’ dan 100 V’a arttırılmasıyla hidratasyon reaksiyonlarının hızlandığı belirlenmiştir

AssistOn-Finger: An under-actuated finger exoskeleton for robot-assisted tendon therapy

We present AssistOn-Finger, a novel under-actuated active exoskeleton for robot-assisted tendon therapy of human fingers. The primary use for the exoskeleton is to assist flexion/extension motions of a finger within its full range, while decreasing voluntary muscle contractions helping to keep the tendon tension levels to stay within acceptable limits, avoiding gap formation or rupture of the suture. The device can also be employed to administer range of motion (RoM)/strengthening exercises. AssistOn-Finger is designed to be passively back-driveable, can cover the whole RoM of patients, and can do so in a natural and coordinated manner. In particular, the device employs human finger as an integral part of its kinematics and when coupled to a human operator, the parallel kinematic structure of exoskeleton supports three independent degrees of freedom, dictated by the kinematics of the human finger. Automatically aligning its joint axes to match finger joint axes, AssistOn-Finger can guarantee ergonomy and comfort throughout the therapy. The self-aligning feature also significantly shortens the setup time required to attach the patient to the exoskeleton. We present the kinematic type selection for the exoskeleton to satisfy the design requirements for tendon therapy applications, detail optimal dimensional synthesis of the device considering trade-offs between multiple design criteria and discuss implementation details of the exoskeleton. We also present feasibility studies conducted on healthy volunteers and provide statistical evidence on the efficacy of exoskeleton driven exercises in keeping the average muscle recruitment and the maximum tendon tension levels as low as human guided therapies

Finger exoskeleton for treatment of tendon injuries

A finger exoskeleton has been developed to aid treatment of tendon injuries. The exoskeleton is designed to assist flexion/extension motions of a finger within its full range, in a natural and coordinated manner, while keeping the tendon tension within acceptable limits to avoid gap formation or rupture of the suture. In addition to offering robot assisted operation modes for tendon therapies, the exoskeleton can provide quantitative measures of recovery that can help guide the physical therapy program. Usability studies have been conducted and efficacy of exoskeleton driven exercises to reduce muscle requitement levels has been demonstrated

Complementary and alternative medicine use in patients with mental disorders in Turkey

Ozturk, Ahmet/0000-0002-9854-7586WOS: 000209440700009PubMed: 24199977Purpose: the aim of this study was to determine the prevalence of complementary and alternative medicine (CAM) use and the associated socio-demographic factors among patients with mental disorders in the Turkish community. Methods: One thousand and twenty-seven patients with a diagnosis of mental disorders who were attending psychiatric outpatient clinics in five Turkish cities were interviewed. A survey questionnaire, which included questions on socio-demographic characteristics and CAM use, was administered face-to-face by psychiatrists. Results: 22.2% of patients with mental disorders were using some form of CAM in the Turkish community. CAM and medication concurrent users had a higher level of education and income compared to CAM users only or medicine users only (p < 0.001). the most common type of CAM used was herbal therapy (n = 146, 64%). Conclusion: Use of CAM by patients with mental disorders should be investigated and taken into account by psychiatrists. (C) 2013 Elsevier Ltd. All rights reserved