SOLVOTHERMAL SYNTHESIS OF BI2WO6 AND ITS PHOTOCATALYTIC ACTIVITY UNDER VISIBLE LIGHT IRRADIATION

Flower-like Bi2WO6 were successfully synthesized using the solvothermal method at different temperatures and characterized by XRD, FE-SEM, and DRS. We also investigated the photocatalytic activity of Bi2WO6 for the decomposition of rhodamine B under visible light irradiation. From XRD and SEM results, the reaction temperature has significant effects on the morphologies of the samples. From DRS results, Bi2WO6 samples displayed the absorption spectrum up to the visible region and then they showed the high photocatalytic activity under visible light irradiation, as a comparison with TiO2-P25

LusRegTes: A Regression Testing Tool for Lustre Programs

Lustre is a synchronous data-flow declarative language widely used for safety-critical applications (avionics, energy, transport...). In such applications, the testing activity for detecting errors of the system plays a crucial role. During the development and maintenance processes, Lustre programs are often evolving, so regression testing should be performed to detect bugs. In this paper, we present a tool for automatic regression testing of Lustre programs. We have defined an approach to generate test cases in regression testing of Lustre programs.  In this approach, a Lustre program is represented by an operator network, then the set of paths is identified and the path activation conditions are symbolically computed for each version. Regression test cases are generated by comparing paths between versions. The approach was implemented in a tool, called LusRegTes, in order to automate the test process for Lustre programs

Combined analysis of acoustic emission and vibration signals in monitoring tool wear, surface quality and chip formation when turning SCM440 steel using MQL

With modern production, Minimum Quantity Lubricant (MQL) technology has emerged as an alternative to conventional liquid cooling. The MQLs is an environmentally friendly lubricant method with low cost while meeting the requirements of machining conditions. In this study, the experimental and analytical results show that the obtained acoustic emission (AE) and vibration signal components can effectively monitor various circumstances in the SCM440 steel turning process with MQL, such as surface quality and chip formation as cutting tool conditions. The AE signals showed a significant response to the tool wear processes. In contrast, the vibration signal showed an excellent ability to reflect the surface roughness during turning with MQL. The chip formation process through the cutting mode parameters (cutting speed, feed and depth of cut) was detected through analysis amplitude of the vibration components Ax, Ay and Az and the AE signal. Finally, Gaussian process regression and adaptive neuro-fuzzy inference systems (GPR-ANFIS) algorithms were combined to predict the surface quality and tool wear parameters of the MQL turning process. Tool condition monitoring devices assist the operator in monitoring tool wear and surface quality limits, stopping the machine in case of imminent tool breakage or lower surface quality. With the unique combination of AE and vibration analysis model and the training and testing samples established by the experimental data, the corresponding average prediction accuracy is 97.57 %. The highest prediction error is not more than 3.8 %, with a confidence percentage of 98 %. The proposed model can be used in industry to predict surface roughness and wear of the tools directly during turnin

SYNTHESIS OF SILVER NANOPARTICLES DOPED IN THE ZEOLITE FRAMEWORK BY CHEMICAL REDUCTION METHOD

ABSTRACT Silver ions (Ag+) were introduced at first into the porous zeolite 4A lattice by an ion-exchange route. And then silver nanoparticles (AgNPs) were synthesized in the zeolite framework by chemical reduction method using hydrazine hydrate (N2H4. H2O) as reducing agent. The synthesized AgNPs/zeolite product was characterized by ultraviolet-visible spectroscopy (UV-vis), X-ray diffraction (XRD), transmission electron microscopy (TEM) and energy dispersive X-ray spectroscopy (EDX). The results showed the maximum absorption wavelength (lmax) of AgNPs/zeolite at 427 nm and the average size of the metallic AgNPs doped in the zeolite of about 30 nm. The synthesis process has been considered as suitable one to prepare AgNPs/zeolite with AgNPs content in zeolite of about 1.2% on large scale. The obtained AgNPs/zeolite product has been used for production of porous ceramic water filters with efficiently bacterial disinfection effect for treatment of drinking water

Adsorptive removal of Pb (II) using exfoliated graphite adsorbent:influence of experimental conditions and magnetic CoFe2O4 decoration

The worm-like exfoliated graphite (EG) based adsorbents prepared from low-cost natural graphite flakes via facile synthesis processes have been found to be efficient adsorbents when it comes to removing Pb (II) from aqueous solution. EG was fabricated by chemical intercalation and microwave assisted exfoliation. Furthermore, the magnetic exfoliated graphite (MEG) was developed by incorporating CoFe2O4 particles into the EG layers using the citric acid based sol-gel technique. Adsorption behaviour of Pb (II) on the as-prepared adsorbents was investigated by taking several experimental conditions into consideration such as contact time, initial concentration, adsorbent dosage, and pH value. The results with initial neutral pH indicated that the adsorption isotherms for Pb (II) on the EG and MEG were well consistent with the Langmuir isotherm model revealing the maximum adsorption capacity of 106 mg/g and 68 mg/g for EG and MEG, respectively. The adsorption kinetics of Pb (II) was found to adhere to the pseudo-second-order kinetic model. The chemical interaction between ? electrons on graphite sheets and Pb (II) ions was suggested to play an essential role in the adsorption mechanism. The introduction of magnetic CoFe2O4 to the EG was found to induce the shift of optimal pH value to a more basic condition. The characterization of the adsorbents was performed using relevant analysis techniques such as Scanning electron microscope (SEM), X–ray powder diffraction (XRD), vibrating-sample magnetometer (VSM), and Fourier-transform infrared (FTIR). The results of this work suggest a high possibility for application of the as-prepared modified graphite to remove hazardous substances in practical wastewater treatment systems. ABSTRAK:  Penyerap Pengelupas Grafit (EG) yang berupa seperti cacing dihasilkan dari grafit semulajadi yang murah melalui proses sintesis serpihan, ia juga merupakan penyerap yang bagus dalam mengasingkan Pb (II) daripada larutan akues. EG direka dengan tindak balas interkalasi kimia dan pengelupasan melalui gelombang mikro. Tambahan, pengelupas grafit magnet (MEG) telah dihasilkan dengan memasukkan zarah CoFe2O4 ke dalam lapisan EG menggunakan teknik sol-gel yang berasaskan asid sitrik. Tindak balas penyerapan Pb (II) pada penyerap yang disiapkan ini, dikaji dengan mengambil kira beberapa keadaan eksperimen seperti waktu disentuh, konsentrasi awal, dos penyerap dan nilai pH.  Hasil keputusan pH neutral awal menunjukkan bahawa isoterm penyerapan bagi Pb (II) pada EG dan MEG adalah konsisten dengan model isoterm Langmuir. Ini menunjukkan kapasiti penyerapan maksimum 106 mg/g dan 68 mg/g bagi EG dan MEG, masing-masing. Penyerapan kinetik Pb (II) didapati mematuhi model kinetik pesudo-order-kedua. Interaksi kimia antara elektron ? pada helaian grafit dan ion Pb (II) memainkan peranan penting dalam mekanisme penyerapan. Pengenalan magnet CoFe2O4 kepada EG didapati telah mengubah nilai pH optimum kepada keadaan asal. Pengelasan penyerapan dilakukan menggunakan teknik analisis yang relevan seperti Mikroskop Elektron Pengimbasan (SEM), Difraksi Serbuk sinar-X (XRD), Magnetometer Sampel-Getaran (VSM) dan Inframerah Perubahan-Fourier (FTIR). Hasil kerja ini mencadangkan kemungkinan besar bagi penggunaan grafit ubah suai yang disediakan bagi membuang bahan berbahaya dalam sistem rawatan air sisa praktikal

Evaluation of mechanical strength and durability characteristics of eco-friendly mortar with cementitious additives

The mechanical strength and durability of eco-friendly mortars used in the repair of marine concrete structures exposed to freshwater and seawater environments were evaluated in this paper. The eco-friendly mortar samples were produced using various ratios of fly ash (FA), ground granulated blast-furnace slag (GGBFS), and silica fume (SF) as cementitious materials. Seven mixtures of eco-friendly mortars, including a control mixture; three mixtures with respective substitutions of GGBFS for Portland cement of 10, 20, and 30% by cement mass; and three mixtures with respective additions of SF of 5, 10, and 15% by total binder mass, were used to produce the samples. Tests, including compressive strength, flexural strength, ultrasonic pulse velocity (UPV), electrical surface resistivity (ESR), rapid chloride ion penetration (RCP), thermal conductivity (TC), and microstructure analysis, were conducted to determine the mechanical strength and durability values of the samples. The experimental results show that replacing Portland cement with GGBFS negatively affected the properties of the mortars by reducing the mechanical strength, UPV, ESR, and TC while increasing the RCP in the samples. Also, adding an appropriate amount of SF could improve the mechanical strength and durability characteristics of the eco-friendly mortars. As a result, the mortar sample containing 30% GGBFS and 10% SF earned compressive and flexural strength values of approximately 49.2 and 13.8 MPa, respectively, at 56 days of curing age. Mortar samples with UPV values >3660 m/s were identified as "high quality". The corrosion resistance of all of the samples was found to be high, particularly in chloride-contaminated environments, due to relatively low (1000 - 2000 Coulombs) RCP values. The best overall performance was recorded for the sample containing 30% GGBFS and 10% SF.Web of Science24455254

Anatomical Characteristics and Variants of Prostatic Artery in Patients of Benign Hyperplasia Prostate by Digital Subtraction Angiography

AIM: This work is aimed to describe anatomical features and variants of the prostatic artery (PA) using digital subtraction angiography (DSA). METHODS: This is a descriptive statistic study. We reviewed the DSA of 348 patients, who had a PA embolisation to reduce the benign prostatic hyperplasia (BPH) symptoms at Radiology Department of Bach Mai Hospital from Oct – 2014 to Oct – 2018. RESULTS: PA was found at 660 pelvic halves, of which 30 pelvic halves (4.5%) had two PAs, 630 pelvic halves had one PA. In terms of the origin of PA, in total 690 PAs, the percentage of type 1, 2, 3, 4 and 5 was successively 33.9%, 13.9%, 18.3%, 23.9% and 10.4%, respectively. Atherosclerosis of PA observed in 20.9%. The ‘corkscrew’ pattern was found in 30.4%. The average diameter of PA was 1.5 ± 0.34mm. The anastomosis of PA with surrounding arteries was common. PA may supply rectum (6.1%), seminal vesical (9.6%), bladder (5.2%), contralateral prostatic parenchyma (13.0%), surrounding soft-tissues (3.5%). CONCLUSION: The common trunk with SVA superior vesical artery was the most common origin of PA. Anastomoses of PA with surrounding tissues were complex

Synthesized BiVO4 was by the co-precipitation method for Rhodamine B degradation under visible light

Recently, BiVO4 photocatalysts has been received much attention in field of catalysts. Because it can be used to degrade harmful organic catalysts in visible light, irradiation produces CO2, H2O and less harmful organic matter. In this study, we have successfully synthesized a BiVO4 photocatalysts via co-precipitation method in the presence of urea and different calcined temperatures. The survey calcined temperatures as 300°C; 350°C; 400°C and 450°C. The obtained materials were characterized by Scanning electron microscope (SEM) and X-ray diffraction (XRD). The photocatalytic activity was evaluated by the photocatalytic degradation of rhodamine B (RhB) degradation under visible compact Philip lamp (40W) light irradiation. The result indicates that all samples calcined are monoclinic scheelite structure of BiVO4. The BiVO4-350°C sample performed the best in the photodegradation of RhB