Effect of cysteine on the electrochemical behavior of Cu10Ni alloy in sulfide polluted environments: Experimental and theoretical aspects

Electrochemical techniques were used to investigate the effect of cysteine (cys) on the dissolution behavior of Cu10Ni alloy in sulfide-polluted salt water through the analysis of the alloy electrochemical behavior including Tafel polarization and electrochemical frequency modulation (EFM) along with scanning electron microscopy (SEM) and energy dispersive X-ray diffraction (EDX). The results showed that cys acts as a mixed type inhibitor. The dissolution rate decreases with increasing cys concentration and increases with increasing the temperature. An adherent layer of inhibitor molecules on the alloy surface is proposed to account for their inhibitive action. The adsorption of cys on the active cathodic sites was found to follow the Langmuir adsorption isotherm from which the thermodynamic parameters of adsorption and corrosion processes were determined and discussed. A synergistic effect was observed between cys and potassium iodide (KI). EFM data are in good agreement with SEM and EDX results.     

Employment of the P-Multiplier in Pile-Group Analysis

This paper discusses the variation of the P-multiplier (Pm) used with the p-y curve to assess the response of a pile group under lateral loads, which is a crucial topic for the design of bridge pile foundations. Pm is influenced by the site geotechnical conditions (i.e., soil profile, type and properties), pile front and side spacings, and pile-group deflection. The presented study shows the needs to incorporate these factors with the recommended sets of Pm to avoid any compromise or uncertainty when Pm is treated as a single (unique) value based only on pile spacings. The current study addresses these influential elements using the strain wedge (SW) model technique, suggested Pm values, and data collected from full-scale pile-group load tests. The experimental results show that Pm is not unique and must be assessed based on the site geotechnical conditions along with the pile-row front and side spacings. Because the employed Pm values must be a function of these influential factors, additional full- and model-scale load tests with different pile spacings and soil types might be required. The paper also emphasizes that using other techniques, such as the SW model, in addition to the P-multiplier could increase the confidence in the predicted pile-group lateral response.     

Analysis and revamping of heat exchanger networks for crude oil refineries using temperature driving force graphical technique

Clean Technologies and Environmental Policy - The refining industry is an energy-intensive industry; most of the energy is consumed in heating and cooling requirements. Revamping or retrofitting of...     

碳纤维布粘贴加固BFRP筋-ECC-混凝土组合梁受弯性能研究

工程结构服役期间经常由于使用功能改变或使用荷载增加而需要对结构进行加固改造。为研究经碳纤维布粘贴加固后的玄武岩纤维增强塑料（BFRP）筋-工程用水泥基复合材料（ECC）-混凝土组合梁的受弯性能,对3组共12根不同ECC高度替换率（0、0.29和0.58）的BFRP筋-ECC-混凝土组合梁底分别粘贴1、2和3层碳纤维布的加固构件及未加固构件进行静力受弯性能试验。研究碳纤维布粘贴层数和ECC高度替换率对组合梁受弯承载力和破坏形态的影响。试验结果表明：采用受拉性能优异的ECC替代受拉区部分混凝土形成的ECC-混凝土组合梁不仅可提高构件承载力,还可有效改善构件抵抗开裂和变形的能力;组合梁底粘贴3层碳纤维布,裂缝宽度可降至未加固试件的10%,受弯承载力提高20%,挠度降低50%。借鉴钢筋混凝土理论,基于合理的基本假定和简化的材料本构模型,提出粘贴碳纤维布加固的组合梁受弯承载力计算式,并给出碳纤维布强度折减系数,理论预测值与试验实测值吻合良好。     

Predicting cement strength in 30 hours

The considerable development in Saudi Arabia has obliged testing stations to make great strides in a short time. Here, scientists at the Materials Testing Laboratory in Riyadh explain how they used an accelerated procedure to predict the compressive strength of different Portland cements within 30 hours. The results were on average within ± 5 per cent of the strengths revealed by the conventional watercuring methods.     

La~(3+) doped LiCo_(0.25)Zn_(0.25)Fe_2O_4 spinel ferrite nanocrystals:Insights on structural,optical and magnetic properties

This paper addresses the manipulation of structural,morphology,optical and magnetic properties of LiCo_(0.25)Zn_(0.25)Fe_2 O_4 ferrite via incorporation of different proportions of La~(3+) at the expense of iron ions using a sol-gel method.The samples were characterized using the X-ray diffraction technique(XRD),Fourier transform infrared(FT-IR) spectroscopy,the energy dispersive X-ray spectra(EDX),inductively coupled plasma optical emission spectroscopy(ICP-OES),high resolution scanning electron microscopy(SEM),Brunauer-Emmett-Teller(BET) surface area analysis,ultraviolet-diffuse reflectance spectroscopy(UV-DRS),and vibrating sample magnetometer(VSM) technique.The Rietveld refinements of the samples indicate that at higher concentrations of La3+,nanostructures with dual phase,i.e.cubic spinel and orthorhombic LaFeO_3 perovskite with space group(Pbnm) appear.Optical studies show that the energy band gap(E_g) of the bare LiCo_(0.25)Zn_(0.25)Fe_2 O_4 ferrite sample(2.18 eV) reaches up to 2.47 eV at x=0.06 and above this concentration,it drops sharply to 2.00 eV.Although the saturation magnetization and the coercivity of LiCo_(0.25)Zn_(0.25)La_xFe_(2-x)O_4 are lower than that of LiCo_(0.25)Zn_(0.25)Fe_2 O_4 NPs.Overall,the superparamagnetic nature and low values of saturation magnetization and coercivity of LiCo_(0.25)Zn_(0.25)La_xFe_(2-x)O_4 NPs are suitable to be applied in transformers core.     

A novel optimized neutrosophic <Emphasis Type="Italic">k</Emphasis>-means using genetic algorithm for skin lesion detection in dermoscopy images

This paper implemented a new skin lesion detection method based on the genetic algorithm (GA) for optimizing the neutrosophic set (NS) operation to reduce the indeterminacy on the dermoscopy images. Then, k-means clustering is applied to segment the skin lesion regions. Therefore, the proposed method is called optimized neutrosophic k-means (ONKM). On the training images set, an initial value of \(\alpha \) in the \(\alpha \)-mean operation of the NS is used with the GA to determine the optimized \(\alpha \) value. The Jaccard index is used as the fitness function during the optimization process. The GA found the optimal \(\alpha \) in the \(\alpha \)-mean operation as \(\alpha _{\mathrm{optimal}} =0.0014\) in the NS, which achieved the best performance using five fold cross-validation. Afterward, the dermoscopy images are transformed into the neutrosophic domain via three memberships, namely true, indeterminate, and false, using \(\alpha _{\mathrm{optimal}}\). The proposed ONKM method is carried out to segment the dermoscopy images. Different random subsets of 50 images from the ISIC 2016 challenge dataset are used from the training dataset during the fivefold cross-validation to train the proposed system and determine \(\alpha _{\mathrm{optimal}}\). Several evaluation metrics, namely the Dice coefficient, specificity, sensitivity, and accuracy, are measured for performance evaluation of the test images using the proposed ONKM method with \(\alpha _{\mathrm{optimal}} =0.0014\) compared to the k-means, and the \(\gamma \)–k-means methods. The results depicted the dominance of the ONKM method with \(99.29\pm 1.61\%\) average accuracy compared with k-means and \(\gamma \)–k-means methods.     

Strain Wedge Model Capability of Analyzing Behavior of Laterally Loaded Isolated Piles, Drilled Shafts, and Pile Groups

This paper demonstrates the application of the strain wedge (SW) model to assess the response of laterally loaded isolated long piles, drilled shafts, and pile groups in layered soil (sand and/or clay) and rock deposits. The basic goal of this paper is to illustrate the capabilities of the SW model versus other procedures and approaches. The SW model has been validated and verified through several comparison studies with model- and full-scale lateral load tests. Several factors and features related to the problem of a laterally loaded isolated pile and pile group are covered by the SW model. For example, the nonlinear behavior of both soil and pile material, the soil-pile interaction (i.e., the assessment of the p-y curves rather than the adoption of empirical ones), the potential of soil to liquefy, the interference among neighboring piles in a pile group, and the pile cap contribution are considered in SW model analysis. The SW model analyzes the response of laterally loaded piles based on pile properties (pile stiffness, cross-sectional shape, pile-head conditions, etc.) as well as soil properties. The SW model has the capability of assessing the response of a laterally loaded pile group in layered soil based on more realistic assumptions of pile interference as compared to techniques and procedures currently employed or proposed.     

Dual feature selection and rebalancing strategy using metaheuristic optimization algorithms in X-ray image datasets

Multimedia Tools and Applications - The imbalance and multi-dimension are two common problems in the medical image datasets, which affect the performances of the image processing procedures. The...