An improved model for predicting effective Young's modulus of the twisted structure under cyclic loading:taking into account the untwisting effect

Twist structures have diverse applications, ranging from dragline, electrical cable, and intelligent structure. Among these applications, tension deformation can＇t be avoided during the fabrication and working processes, which often leads to the twist structure rotation （called untwisting effect） and twist pitch increasing. As a consequence, this untwisting behavior has a large effect on the effective Young＇s modulus. In this paper, we present an improved model based on the classical Costello＇s theory to predict the effective Young＇s modulus of the basic structure, twisted by three same copper strands under cyclic loading. Series of experiments were carried out to verify the present model taking into account the untwisting effect. The experimental results have better agreements with the presented model than the common Costello＇s model.

The Analysis of the Untwisting and Retwisting Methods in Determining the Twist of OE Yarn

The twists of twelve kinds of the cotton OE yarns in different machine twists and different yarn linear density have been determined by one time back twisting and twisting method, triple twisting method and double twisting method. The quantitative analysis of the measurement principles of all the untwisting and retwisting methods has been made by the writers. It is theoretically and practically concluded that for twelve kinds of the cotton OE yarns the difference between the twist determined by triple twisting method and machine twist is the lowest and there is measuring method error in determining the twist of OE yarn by all the untwisting and retwisting methods.

Torsional Dynamics and 2D Speckle Tracking in Heart Failure with Reduced Ejection Fraction on Patients Taking Sacubitril/Valsartan and Naive

This study aims to evaluate the torsional dynamics and 2D speckle tracking in heart failure with reduced ejection fraction on patients taking angiotensin receptor neprilysin inhibitors (ARNI) and none.?ARNI has been shown to be superior to enalapril in?the?long term reducing the mortality and hospitalization of heart failure (HF). However short-term effects on diastolic function remain unclear. We sought to evaluate 6 months' effects of ARNI on left ventricular (LV) diastolic parameters determined by speckle tracking and tissue Doppler imaging. This study was carried out in Menoufia University Hospitals including 60 patients of HFrEF during the period from August 2019 to January 2020. (50%) of patients were?treated with traditional treatment of heart failure and the remaining were?treated with ARNI. Data were collected including history and clinical examination. ECG and speckle tracking and tissue Doppler imaging were?done to evaluate the diastolic function. Our results showed no significant difference between the two groups at baseline. There was?a?significant improvement?in?the LV diastolic function parameters. Untwisting?time and untwisting?onset showed the highly significant parameters of improvement. This study concluded that ARNI showed short term improvement of diastolic function of the left ventricle that could be detected by STE.

Study on Pneumatic Splice

An ideal pneumatic splice has not only interminglings in the middle, but also many small wrappings on both sides of the spliced region, and must have near overlapping loopy wrappings at both ends. Only the fluffy and hairy untwisted yarn ends obtained from a swirling jet untwisting can generate many small wrappings when spliced.To get the fluffy and hairy untwisted yarn ends, a small swirling intensity value X must be used to eliminate a reverse flow zone. To increase the wrappings at both ends, a larger swirling intensity value X must be used to form a reverse flow zone. Only a perfect splice can better the yarn’s appearance,increase its strength and make it impossible for its fibers to slip easily.

无捻玻纤增强技术及其对PCB基材性能的改进

根据近期看到的有关技术资料,介绍了无捻玻纤增强技术的原理、方法和对PCB基材性能改进的情况。

Studies on the Interaction of Poly (I:C) With Cu^(2+)

Metal ions play important roles in the biological functions of nucleic adds. It is of importance to the life sciences to investigate the reaction of nucleic acids with metal ions. In the note the interaction of double-stranded helical structure nucleic acid, polyinosinic acid: polycytidylic acid （poly （I:C）） with Cu2+ is studied by means of absorption spectra, circular dichroism, fluorescent spectra, melting and cooling curves, acid titration curves and ethidium bromide fluorescent probe. The results show that Cu2+ breaks the hydrogen-bonded structure of poly （I: C）, and the poly （I: C） untwisting induced by Cu2+ is un-reversible and the apparent binding constant of poly （I: C） with Cu2+ is 1.23×104