The Study of Fabric Drying Using Direct-Contact Ultrasonic Vibration

Our existing cloth drying technology is an energy-intensive process, which generally involves blowing hot air across tumbling wet fabrics to facilitate evaporation and moisture removal. To address the relatively low energy efficiency of existing cloth drying techniques, in this chapter, a totally new cloth drying technology is introduced, which uses high frequency ultrasonic vibrations generated by piezoelectric transducer instead of thermal heating to extract moisture in cloth as a cold mist, dramatically reducing drying time and energy consumption. The physical mechanism of ultrasonic fabric drying process in direct-contact mode is first studied. A novel ultrasonic transducer driving method, in which the power supply to the transducer is regulated by a binary modulating signal, is then developed for use in direct-contact ultrasonic drying of fabrics. A demonstration unit is finally fabricated to show the efficacy of the process and its energy saving compared to thermal drying process

Screening Characteristics of TIMI Score in Predicting Acute Coronary Syndrome Outcome; a Diagnostic Accuracy Study

Introduction: In cases with potential diagnosis of ischemic chest pain, screening high risk patients for adverse outcomes would be very helpful. The present study was designed aiming to determine the diagnostic accuracy of thrombolysis in myocardial infarction (TIMI) score in Patients with potential diagnosis of ischemic chest pain.Method: This diagnostic accuracy study was designed to evaluate the screening performance characteristics of TIMI score in predicting 30-day outcomes of mortality, myocardial infarction (MI), and need for revascularization in patients presenting to ED with complaint of typical chest pain and diagnosis of unstable angina or Non-ST elevation MI.Results: 901 patients with the mean age of 58.17 ± 15.00 years (19-90) were studied (52.9% male). Mean TIMI score of the studied patients was 0.97 ± 0.93 (0-5) and the highest frequency of the score belonged to 0 to 2 with 37.2%, 35.3%, and 21.4%, respectively. In total, 170 (18.8%) patients experienced the outcomes evaluated in this study. Total sensitivity, specificity, positive and negative predictive value, and positive and negative likelihood ratio of TIMI score were 20 (95% CI: 17 – 24), 99 (95% CI: 97 – 100), 98 (95% CI: 93 – 100), 42 (95% CI: 39 – 46), 58 (95% CI: 14 – 229), and 1.3 (95% CI: 1.2 – 1.4), respectively. Area under the ROC curve of this system for prediction of 30-day mortality, MI, and need for revascularization were 0.51 (95% CI: 0.47 – 0.55), 0.58 (95% CI: 0.54 – 0.62) and 0.56 (95% CI: 0.52 – 0.60), respectively.Conclusion: Based on the findings of the present study, it seems that TIMI score has a high specificity in predicting 30-day adverse outcomes of mortality, MI, and need for revascularization following acute coronary syndrome. However, since its sensitivity, negative predictive value, and negative likelihood ratio are low, it cannot be used as a proper screening tool for ruling out low risk patients in ED

The Relationship between Multiple Intelligences and Performance of EFL Students in Different Forms of Reading Comprehension Tests

The major aim of this study was to investigate the relationship between Multiple Intelligences (MI) scores and the performance of Iranian EFL students on different forms of reading comprehension tests. To this aim, 90 learners of English from Parax Institute of Science and Technology (Mashhad Branch) were selected. They were asked to complete MIDAS multiple intelligences questionnaire and a reading test, which included two tests formats (multiple-choice and cloze test). The result of the correlational study indicated that the total MI score correlated positively with performance on multiple-choice and cloze test. Out of its 8 sub-intelligences linguistic, intrapersonal, spatial, and mathematical intelligence correlated positively with multiple-choice test of reading. Performance on cloze test correlated positively with linguistic, spatial, and mathematical intelligence.  The results of regression equations also showed that MI scores predict both the performance on multiple-choice and cloze test. Out of its sub-intelligences, linguistic intelligence and musical intelligence predict performance on multiple-choice questions and linguistic intelligence predicts performance on cloze test

Microscale Study of Nucleation Process in Boiling of Low-Surface-Tension Liquids

A novel MEMS device has been developed to study some of the fundamental issues surrounding the physics of the nucleation process intrinsic to boiling heat transfer. The study was focused on boiling of FC-72 liquid. Over the past 50 years, scientists have developed several competing mechanistic models to predict the boiling heat transfer coefficient. Although the developed models are intended to predict the heat transfer coefficient at macroscales, their fundamental assumptions lie on complex microscale sub-processes that remain to be experimentally verified. Two main unresolved issues regarding these sub-processes are: 1) bubble growth dynamics and the relative importance of different mechanisms of heat transfer into the bubble and 2) vapor/liquid/surface thermal interactions and the bubble's role in heat transfer enhancement during the nucleation process. The developed device generates bubbles from an artificial nucleation site centered within a radially distributed temperature sensor array (with 22-40 microns spatial resolution) while the surface temperature data and images of the bubbles are recorded. The temperature data enabled numerical calculation of the surface heat flux. Using the test results, the microlayer contribution to the bubble growth was determined to increase from 11.6% to 22% when surface temperature was increased from 80 C to 97 C. It was determined that the transient conduction process occurs predominantly at the bubble/surface contact area, and before the bubble departure, contrary to what has been commonly assumed in classical boiling models. For the first time, the convection heat transfer outside the contact area (often known as microconvection) and transient conduction within the contact area were differentiated. The microconvection heat flux was found to be relatively close to that of the equivalent natural convection produced by the same geometry, but becomes significantly stronger than natural convection at higher surface temperatures. Test results under saturation conditions showed that when surface temperature is increased from 80 C to 97 C, the contribution of the different mechanisms of heat transfer within a circular area of diameter equal to that of the bubble changes from: 1) 28.8% to 16.3% for microlayer, 2) 45.3% to 32.1% for transient conduction, and 3) 25.8% to 51.6% for microconvection