Double Glow Plasma Surface Alloying Process Modeling Using Artificial Neural Networks

A model is developed for predicting the correlation between processing parameters and the technical target of double glow by applying artificial neural network (ANN). The input parameters of the neural network (NN) are source voltage, workplace voltage, working pressure and distance between source electrode and workpiece. The output of the NN model is three important technical targets, namely the gross element content, the thickness of surface alloying layer and the absorption rate (the ratio of the mass loss of source materials to the increasing mass of workpiece) in the processing of double glow plasma surface alloying. The processing parameters and technical target are then used as a training set for an artificial neural network. The model is based on multiplayer feedforward neural network. A very good performance of the neural network is achieved and the calculated results are in good agreement with the experimental ones.

XPS study of the corrosion resisting composite alloying layer obtained by double glow plasma with the brush plating Ni interlayer

The Ni-Cr-Mo-Cu multi-element surface alloying with the electric brushplating Ni interlayer on the low carbon steel substrate has been investigated. By theelectrochemical method in 3.5 percent (mass fraction) NaCl solution, the corrosion resistance of thecomposite alloying layer and single alloying layer is determined. The experimental results showthat the corrosion resistance of the composite alloying layer is obviously better than that of thesingle alloying layer. The structure and composition of passive films formed on the two kinds ofalloyed layers after electrochemical tests in 3.5 percent NaCl solution have been studied usingX-ray photoelectron spectroscopy (XPS). It is concluded that the double glow plasma surface alloyingof low carbon steel with the electric brush plating Ni interlayer is an appropriate technique toenhance the corrosion resistance compared with the single double glow surface alloying.

Effects of antihypertensives on arterial responses associated with obstructive sleep apneas

Background Many patients with obstructive sleep apnea syndrome (OSAS) have complicated with hypertension and may be prescribed with antihypertension medications to control their blood pressure But whether antihypertension medications can also decrease arterial stiffness or control the blood pressure increasing following obstructive events is not well described This study aimed to investigate whether antihypertensive medications can ameliorate the changes in arterial stiffness and blood pressure associated with OSA Methods Sixtyone OSAS patients [13 women, 48 men, mean age (534±123) years], 26 normotensive patients (N), 7 hypertensive patients on no antihypertension medications (H), and 28 hypertensive patients on various combination antihypertension therapy (HM), were prospectively diagnosed with standard nocturnal polysomnography Beattobeat blood pressure was continuously recorded from the radial artery by applanation tonometry during baseline sleep As a measure of arterial stiffness, arterial augmentation index (AAI) was calculated as the ratio of augmented systolic blood pressure (SBP) to pulse pressure and expressed as a percentage for the following conditions: awakening, the first 10 ('early apnea') and last 10 ('late apnea') cardiac cycles of obstructive events (apnea or hypopnea), and the first 15 cardiac cycles following event termination ('post apnea') for all events with nadir O2 saturation ≤89% Results Systolic blood pressure (SBP) postapnea [(14274±1306) mmHg (N), (13706±2656) mmHg (H), (13694±141) mmHg (HM)] was significantly increased from awakening [(13576±1476) mmHg (N), (13558±2317) mmHg (H), (12977±1400) mmHg (HM)], early apnea [(13053±1265) mmHg (N), (12447±2497) mmHg (H), (12604±1312) mmHg (HM)], and late apnea [(1298±1268) mmHg(N), (12478±2515) mmHg (H), (12448±1382) mmHg (HM)] respectively (P<0001, repeated measures ANOVA) AAI was significantly increased for the N group (P<0001) from awakening to late apnea [(1045±262)% vs (1443±321)%] and from early apnea to late apnea [(1061±234)% vs (1443±321)%], and also for H group (P<005) from awakening to late apnea [(1123±387)% vs (1632±802)%] and from early apnea to late apnea [(1175±379)% vs (1632±802)%] Meanwhile, no significant differences in AAI among awakening, early apnea, late apnea, and postapnea conditions were found in HM group Conclusions The current data demonstrate that systemic blood pressure increases significantly during the postapneic phase of OSAS, compared with that during awakening and intraapnea phases even with the use of combined antihypertensive therapy which could normalize BP during awakening in the hypertensive patients However, increases in arterial stiffness during obstructive events could be ameliorated by combined antihypertension medications