Simultaneous X-ray diffraction and phase-contrast imaging for investigating material deformation mechanisms during high-rate loading

Using a high-speed camera and an intensified charge-coupled device (ICCD), a simultaneous X-ray imaging and diffraction technique has been developed for studying dynamic material behaviors during high-rate tensile loading. A Kolsky tension bar has been used to pull samples at 1000 s(−1) and 5000 s(−1) strain-rates for super-elastic equiatomic NiTi and 1100-O series aluminium, respectively. By altering the ICCD gating time, temporal resolutions of 100 ps and 3.37 µs have been achieved in capturing the diffraction patterns of interest, thus equating to single-pulse and 22-pulse X-ray exposure. Furthermore, the sample through-thickness deformation process has been simultaneously imaged via phase-contrast imaging. It is also shown that adequate signal-to-noise ratios are achieved for the detected white-beam diffraction patterns, thereby allowing sufficient information to perform quantitative data analysis diffraction via in-house software (WBXRD_GUI). Of current interest is the ability to evaluate crystal d-spacing, texture evolution and material phase transitions, all of which will be established from experiments performed at the aforementioned elevated strain-rates

Design and Analysis of a Linear Memory Machine for Ocean Wave Power Generation

In this paper, a permanent magnet (PM) linear memory machine is proposed for ocean wave power generation. A notable feature of this machine is its online tunable mnemonic flux. This enables it to operate efficiently in a wide speed range and makes it suitable for the variable-speed wave-power generation. Moreover, this machine has both the PMs and the windings arranged in its stator so that it does not need slip rings or brushes. The proposed machine is also robust and cost-effective because it has a simple translator of slotted steel. In this paper, the configuration and working principle of the linear memory machine are firstly introduced. The results of a parametric analysis are presented to investigate the effects of the proposed machine’s geometric parameters. The performance of the proposed machine is then analyzed using time-stepping finite element method (TS-FEM)

Design and Analysis of a Novel Double-Stator Double-Rotor Motor Drive System for In-Wheel Direct Drive of Electric Vehicles

In-wheel direct drive (IWDD) of electric vehicles (EVs), which simplifies the transmission system and facilitates flexible control of vehicle dynamics, has evolved considerably in the EV sector. This paper proposes a novel double-stator double-rotor motor (DSDRM) with a bidirectional flux modulation effect for in-wheel direct drive of EVs. With the proposed special design, a synthetic-slot structure with synthetic materials containing copper and permanent magnets (PMs) in the slots of the motor is ingeniously employed, and the outer and inner rotors are mechanically connected together as a single rotor, making its mechanical structure less complicated than those of two-rotor machines. The main work of this paper involves the design, analysis, construction, and testing of the proposed machine. The DSDRM with a synthetic-slot structure was demonstrated to be feasible by finite element analysis (FEA), prototype fabrication, and experimental results. In addition, vehicle layout with DSDRM is presented and verified by the vehicle road test experiment. Thus, the DSDRM with the synthetic-slot structure can be used as a hub motor for in-wheel direct drive of EVs

A Novel Approach of Periodate Oxidation Coupled with HPLC-FLD for the Quantitative Determination of 3‑Chloro-1,2-propanediol in Water and Vegetable Oil

A novel approach of periodate oxidation coupled with high-performance liquid chromatography (HPLC)–fluorescence detection (FLD) for the quantitative determination of 3-chloro-1,2-propanediol (3-MCPD) has been established. The essence of this approach lies in the production of chloroacetaldehyde by the oxidization cleavage of 3-MCPD with sodium periodate and the HPLC analysis of chloroacetaldehyde monitored by an FLD detector after fluorescence derivatization with adenine. The experimental parameters relating to the efficiency of the derivative reaction such as concentration of adenine, chloroacetaldehyde reaction temperature, and time were studied. Under the optimized conditions, the proposed method can provide high sensitivity, good linearity (<i>r</i>² = 0.999), and repeatability (percent relative standard deviations between 2.57% and 3.44%), the limits of detection and quantification were 0.36 and 1.20 ng/mL, respectively, and the recoveries obtained for water samples were in the range 93.39–97.39%. This method has been successfully applied to the analysis of real water samples. Also this method has been successfully used for the analysis of vegetable oil samples after pretreatment with liquid–liquid extraction; the recoveries obtained by a spiking experiment with soybean oil ranged from 96.27% to 102.42%. In comparison with gas chromatography or gas chromatography–mass spectrometry, the proposed method can provide the advantages of simple instrumental requirement, easy operation, low cost, and high efficiency, thus making this approach another good choice for the sensitive determination of 3-MCPD

Effects of sacubitril/valsartan versus olmesartan on central hemodynamics in the elderly with systolic hypertension novelty and significance

Effective treatment of systolic hypertension in elderly patients remains a major therapeutic challenge. A multicenter, double-blind, randomized controlled trial with sacubitril/valsartan (LCZ696), a first-in-class angiotensin receptor neprilysin inhibitor, was conducted to determine its effects versus olmesartan (angiotensin receptor blocker) on central aortic pressures, in elderly patients (aged ≥60 years) with systolic hypertension and pulse pressure >60 mm Hg, indicative of arterial stiffness. Patients (n=454; mean age, 67.7 years; mean seated systolic blood pressure, 158.6 mm Hg; mean seated pulse pressure, 69.7 mm Hg) were randomized to receive once-daily sacubitril/valsartan 200 mg or olmesartan 20 mg, force titrated to double the initial doses after 4 weeks, before primary assessment at 12 weeks. The study extended double-blind treatment for 12 to 52 weeks, during which amlodipine (2.5–5 mg) and subsequently hydrochlorothiazide (6.25–25 mg) were added-on for patients not achieving blood pressure target (<140/90). At week 12, sacubitril/valsartan reduced central aortic systolic pressure (primary assessment) greater than olmesartan by −3.7 mm Hg (P=0.010), further corroborated by secondary assessments at week 12 (central aortic pulse pressure, −2.4 mm Hg, P<0.012; mean 24-hour ambulatory brachial systolic blood pressure and central aortic systolic pressure, −4.1 mm Hg and −3.6 mm Hg, respectively, both P<0.001). Differences in 24-hour ambulatory pressures were pronounced during sleep. After 52 weeks, blood pressure parameters were similar between treatments (P<0.002); however, more patients required add-on antihypertensive therapy with olmesartan (47%) versus sacubitril/valsartan (32%; P<0.002). Both treatments were equally well tolerated. The PARAMETER study (Prospective Comparison of Angiotensin Receptor Neprilysin Inhibitor With Angiotensin Receptor Blocker Measuring Arterial Stiffness in the Elderly), for the first time, demonstrated superiority of sacubitril/valsartan versus olmesartan in reducing clinic and ambulatory central aortic and brachial pressures in elderly patients with systolic hypertension and stiff arteries