In this study, ultrasonic bath and milling processes were used to synthesis epoxy resin-multiwalled carbon nanotubes (MWCNT) composite, and their effect on the absorption of magnetic waves was investigated using the Vector Network Analyzer (VNA) test. The effect of the concentration of MWCNT used to attract the wave's magnetic part in the epoxy resin matrix is also investigated. This study showed that the optimal amount of MWCNT in this epoxy resin-MWCNT composite was about 5 wt.% for the ultrasonic bath method, while it was around 15 wt% for the milling method. The ultrasonic bath caused the reflection losses (RL) value reaches to about -25 dB in the range of 9 to 11 GHz. The results of the VSM test showed that the composite produced from epoxy resin and MWCNT is a soft magnetic material. Also, the sample produced in the ultrasonic bath process has a higher magnetic saturation than the milling process, which causes it to absorb more electromagnetic waves. Manuscript profile

The structural and magnetic properties of the polyethylene glycol (PEG) coated nickel spinel ferrite (NiFe2O4) nanoparticles have been reported in the present study. NiFe2O4 nanoparticles were prepared by solution plasma method using KOH + Na2Co3 as electrolyte. The prepared powder of nickel ferrite nanoparticles was annealed at 800 ˚C for two h and used for further study. The X-ray analysis confirmed the formation of a cubic spinel single-phase structure. The crystallite size, lattice parameter, and X-ray density of the PEG-coated NiFe2O4 nanoparticles were calculated using XRD data. TEM and FTIR studies revealed the presence of PEG on nickel ferrite nanoparticles and reduced agglomeration in the NiFe2O4 nanoparticles. The pulse-field hysteresis loop tracer technique studied the magnetic properties at room temperature. The magnetic parameters such as saturation magnetization, remanence magnetization, and coercivity have been obtained. These magnetic parameters were get decreased by PEG coating. Manuscript profile

A simple polymer-assisted wet chemical method was used to synthesize NiAl2O4 nanopowder. The photocatalytic properties of synthesized powders were investigated for the degradation of methylene blue. For this aim, metal salts and polymeric precursors were dissolved in water, and then a crosslinker was added till a gel was formed. The product was calcined to produce nanopowders. XRD results confirmed the formation of nickel aluminate with spinel structure. In addition, the findings showed that the produced NiAl2O4 nanopowders have a particle size range between 35 to 100 nm with a uniform particle size distribution. The optical properties of the samples showed that the bandgap energy of NiAl2O4 is about 3.44 eV. The nickel aluminate nanopowders demonstrated high photocatalytic activity for photodegradation of methylene blue, which could be attributed to their small particle sizes. It seems that the polymer-assisted wet chemical synthesis may open up an effective route for the production of ceramic photocatalyst nanopowders with high quality. Manuscript profile

The present study develops a semi-instantaneous baseline damage identification approach to identify the delamination damage. An active sensing network with (Ba0.95Ca0.05)(Ti0.91Sn0.09)O3 (BCTS) lead-free piezoelectric transducers that were mounted on the two undamaged and damaged (with the delamination) plates. The wavelet transform was used for extracting the energy ratio change which is an effective and robust characteristic from the collected time-domain signals. The “identicality coefficient” (IC) was obtained for each sensing path under pristine structural conditions and used to eliminate any inequalities in the signals of each path. The output wave signals of samples were investigated by experiment and the finite element method. The values of the index produced by damages were significant against the threshold value set. The errors were less than 4%, which may be related to the linear relationship considered for the DI and delamination damage. A comparative of sensing paths showed a significant difference between both healthy and damaged samples. The delaminated damage was detected because the delamination phenomenon increased the amplitude of the wave and the wave energy. The comparison of the “damage index” (DI) values of six sensing paths showed that the path with delamination damage had the highest DI value i.e., 0.92 and then the sensing paths closest to the damage showed the highest DI values (DI=0.67). The path with a distance farther from the damage shows DI=0.09. The other DI values of other sensing paths were close to zero (DI=0) due to no damage. Manuscript profile

Bulk g-C3N4 has very poor photocatalytic activity. Many methods have been utilized to increase the photocatalytic performance of this semiconductor. Here, a simple preparation was used to create exfoliated g-C3N4 that was co-doped with sodium and tungsten. The produced Na-W co-doped exfoliated g-C3N4 was characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM), UV-vis spectroscopy, and Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS). The doping samples with Na and W changed the band structure of the g-C3N4 lattice, which increased light absorption and caused a reduction in the band gap. The samples had layered morphology. After exfoliation and sodium and tungsten co-doping of the samples, the methylene blue photodegradation was greatly enhanced. The doping of the samples also had an impact on the dye adsorption capacity. The dye removal activity of the Na-W co-doped exfoliated g-C3N4 sample is higher than those of pure bulk g-C3N4 and pure exfoliated g-C3N4. The rate reaction constant (k) of the Na-W co-doped exfoliated g-C3N4 is up to 3.3 times greater than that of bulk g-C3N4. The produced photocatalyst may be utilized for the treatment of wastewater comprising methylene blue as the pollutant agent. Manuscript profile

دیرگدازهای منیزیا- گرافیت، بدلیل خواص مناسب که عمدتاً به حضور گرافیت و اتصال کربنی و تطابق بهینه منیزیا با شرایط فولادسازی ارتباط می یابد؛ کاربرد وسیعی در صنعت فولاد یافته است. از عمده معایب این دسته دیرگدازها، عدم اتصال مناسب در درجه حرارت بالا می باشد. در کار تحقیقاتی حاضر سعی گردیده با استفاده از منیزیای فیوزد، گرافیت و نیتریده کردن سیلیسیم در اتمسفر ازت، فاز نیتریدی تشکیل و تاثیر آن بر خواص فیزیکی، مکانیکی، آنالیز فازی و ریز‌‌ساختاری بررسی گردد. نتایج نشان داد که حضور همزمان فازهای فورستریت و نیترید سیلیسیم باعث ایجاد خواص بهینه ترمومکانیکی در دیرگدازهای منیزیا-گرافیت می گردد و استحکام فشاری24Kn/mm2 را در نمونه بهینه میتوان مشاهده نمود. Manuscript profile

نانو کامپوزیت ZnO-CdO با استفاده از روش میکروامولسیون آب در روغن سنتز شد. نسبت وزنی اکسید روی و کادمیم و دمای کلسیناسیون بر روی مورفولوژی، تشکیل فاز، تبدیلات فازی، اندازه کریستال هاوذرات و همچنین سطح ویژه نانو کامپوزیت ZnO-CdO تحقیق شد. محصولات سنتز شده توسط آنالیزهای XRD، BET، SEM، TEM و مورد بررسی قرار گرفت. نتایج پراش اشعه ایکس نشان داد که نانو کامپوزیت ZnO-CdO با کریستال‌های نانومتری شکل گرفته است، ذرات نانو کامپوزیت روی-کادمیم سنتز شده در دمای˚C400 به دلیل سطح ویژه بالاتر بهترین خواص جذب و تجزیه متیل بلو و متیل اورانژ اسیدی را از خود نشان دادند. Manuscript profile