Active structural acoustic control of a smart cylindrical shell using a virtual microphone

Loghmani, Ali,Danesh, Mohammad,Kwak, Moon K,Keshmiri, Mehdi Institute of Physics Publishing 2016 Smart materials & structures Vol.25 No.4

<P>This paper investigates the active structural acoustic control of sound radiated from a smart cylindrical shell. The cylinder is equipped with piezoelectric sensors and actuators to estimate and control the sound pressure that radiates from the smart shell. This estimated pressure is referred to as a virtual microphone, and it can be used in control systems instead of actual microphones to attenuate noise due to structural vibrations. To this end, the dynamic model for the smart cylinder is derived using the extended Hamilton’s principle, the Sanders shell theory and the assumed mode method. The simplified Kirchhoff–Helmholtz integral estimates the far-field sound pressure radiating from the baffled cylindrical shell. A modified higher harmonic controller that can cope with a harmonic disturbance is designed and experimentally evaluated. The experimental tests were carried out on a baffled cylindrical aluminum shell in an anechoic chamber. The frequency response for the theoretical virtual microphone and the experimental actual microphone are in good agreement with each other, and the results show the effectiveness of the designed virtual microphone and controller in attenuating the radiated sound.</P>

Design of a virtual acoustic sensor for estimating the radiated sound of cylindrical shells

A. Loghmani,M. Danesh,M.K. Kwak,M. Keshmiri 한국소음진동공학회 2015 한국소음진동공학회 학술대회논문집 Vol.2015 No.10

In this paper, a virtual acoustic sensor is designed and evaluated experimentally to be used instead of microphones in active noise control of vibrating cylindrical shells. Dynamic motion equations of a cylindrical shell along with the effect of bonded piezoelectric patches are derived based on the Hamilton’s principle and Rayleigh-Ritz method. The Sanders shell theory is used to relate the strains to the displacements of the cylinder. Modal structural acoustic sensing technique estimates the far-field radiated sound pressure of the cylinder. Experimental frequency response function (FRF) of the actual microphone at various locations are obtained and compared to that of the virtual one. The theoretical estimated sound pressure is in good agreement with the experimental results.

Glutathione-responsive hydrogel and molecularly imprinted polymer nanospheres: New aspect on cisplatin delivery

Mohammad Hassan Loghmani,Abdollah Fallah Shojaie,Seyyedeh Azadeh Hosseini 한국공업화학회 2021 Journal of Industrial and Engineering Chemistry Vol.96 No.-

In this study, Glutathione-responsive hydrogel, MIPs and their related NIPs were synthesized byprecipitation polymerization method. Effect of HEMA/MAA and EGDMA/TRIM as functional monomerand crosslinking agents on size, morphology, drug loading and releasing were studied. BACy as a disulfidecross-linking agent was used in praparation of Glutathione-responsive hydrogel. The size andmorphology of MIPs and NIPs were examined by FE-SEM technique. Results showed EGDMAsynthesizedMIPs had the smaller size than TRIM-prepared MIPs. In order to measure the capacity of MIPsor NIPs for binding to cisplatin, static and dynamic adsorption experiments were done. The amounts ofcisplatin were measured by HPLC method. The binding capacity of drug by MIPs is observed to be higherthan NIPs. The EGDMA-synthesized polymers showed a high percentage of adsorption. NIPs weresaturated much sooner than MIPs. In vitro release assays of cisplatin were done in PBS at pH = 7.4 andtemperature of 37 C. The results showed that increase of the amount of GSH cause to increase release ofthe drug from hydrogel.

An Investigation into the Impact of Fiber Material, Fabric Texture, Dirt Type, and Fabric Area Density on Ultrasonic Cleaning of Woven Textiles

Ali Rezaei,Ali Loghmani,Sayyed Mahdi Hejazi,Aminollah Mohammadi 한국섬유공학회 2023 Fibers and polymers Vol.24 No.12

In recent years, there has been a growing interest in the application of ultrasonic cleaning techniques to textiles. However, the impact of textile properties on the cleaning performance has not been studied yet. This paper addresses this gap by systematically investigating the influence of different factors including fabric type, dirt type, and ultrasonic frequency, on the cleaning efficacy of textiles. To this end, four distinct fabric types, characterized by variations in texture, fiber material, and area density, were selected for experimentation. Additionally, two distinct dirt types, derived from chocolate milk and a carbon black-paraffin mixture, were introduced to assess their specific effects on ultrasonic cleaning. To analyze the impact of ultrasonic frequency, two transducers operating at frequencies of 19.5 Hz and 32.5 Hz were designed and fabricated. The quality of cleaning on the fabric samples, stained with the aforementioned dirt types, was evaluated using a full factorial experimental design. Measurement of washing quality was carried out employing a spectrophotometer. The findings of this investigation reveal that an increase in frequency is associated with a reduction in cleaning performance. Furthermore, the type of fabric texture directly influences the extent to which dirt stains are removed from the fabric. The choice of fiber material plays a crucial role in determining the textile's hydrophilic or hydrophobic characteristics, which, in turn, significantly impacts the bonding between textile yarn and various types of dirt. Consequently, the overall cleaning efficiency of the textile is affected by these interrelated factors.

Effect of Microwave Irradiation on Morphology and Size of Anatase Nano Powder: Efficient Photodegradation of 4-Nitrophenol by W-doped Titania

Shojaei, Abdollah Fallah,Loghmani, Mohammad Hassan Korean Chemical Society 2012 Bulletin of the Korean Chemical Society Vol.33 No.12

Anatase nanocrystalline and its tungsten-doped (0.4, 2, and 4 mol %) powders have been synthesized by microwave irradiation through hydrolysis of titanium tetra-isopropoxide (TIP) in aqueous solution. The materials are characterized by XRD, Raman, SEM-EDX, TEM, FT-IR and UV-vis techniques. The nanocrystalline $TiO_2$ particles are 30 nm in nature and doping of tungsten ion decreases their size. As seen in TEM images, the crystallites of W (4 mol %) doped $TiO_2$ are small with a size of about 10 nm. The photocatalytic activity was tested on the degradation of 4-nitrophenol (4-NP). Catalytic activities of W-doped and pure $TiO_2$ were also compared. The results show that the photocatalytic activity of the W-doped $TiO_2$ photocatalyst is much higher than that of pure $TiO_2$. Degradation decreases from 96 to 50%, during 115 min, when the initial 4-NP concentration increases from 10 to 120 ppm. Maximum degradation was obtained at 35 mg of photocatalyst.

Effect of Microwave Irradiation on Morphology and Size of Anatase Nano Powder: Efficient Photodegradation of 4-Nitrophenol by W-doped Titania

Abdollah Fallah Shojaei,Mohammad Hassan Loghmani 대한화학회 2012 Bulletin of the Korean Chemical Society Vol.33 No.12

Anatase nanocrystalline and its tungsten-doped (0.4, 2, and 4 mol %) powders have been synthesized by microwave irradiation through hydrolysis of titanium tetra-isopropoxide (TIP) in aqueous solution. The materials are characterized by XRD, Raman, SEM-EDX, TEM, FT-IR and UV-vis techniques. The nanocrystalline TiO2 particles are 30 nm in nature and doping of tungsten ion decreases their size. As seen in TEM images, the crystallites of W (4 mol %) doped TiO2 are small with a size of about 10 nm. The photocatalytic activity was tested on the degradation of 4-nitrophenol (4-NP). Catalytic activities of W-doped and pure TiO2 were also compared. The results show that the photocatalytic activity of the W-doped TiO2 photocatalyst is much higher than that of pure TiO2. Degradation decreases from 96 to 50%, during 115 min, when the initial 4-NP concentration increases from 10 to120 ppm. Maximum degradation was obtained at 35 mg of photocatalyst.

High Selective Oxidation of Alcohols Based on Trivalent Ion (Cr³⁺ and Co³⁺) Complexes Anchored on MCM-41 as Heterogeneous Catalysts

Shojaei, Abdollah Fallah,Rafie, Mahboubeh Delavar,Loghmani, Mohammad Hassan Korean Chemical Society 2012 Bulletin of the Korean Chemical Society Vol.33 No.8

Cr(III) and Co(III) complexes with acetylacetonate were anchored onto a mesoporous MCM-41 through Schiff condensation. The materials were characterized by XRD, FT-IR, BET, CHN and ICP techniques. Elemental analysis of samples revealed that one C=N bond was formed through Schiff condensation on MCM-41 surface. The catalysts were tested for the alcohol oxidations using t-butyl hydroperoxide (TBHP) and $H_2O_2$ as oxidant. The catalytic experiments were carried out at both room temperature and reflux condition. Various solvents such as dichloromethane, acetonitrile and water were examined in the oxidation of alcohols. Among the different solvents, catalytic activity is found more in acetonitrile. Further, the catalysts were recycled three times in the oxidation of alcohols and no major change in the conversion and selectivity is observed, which shows that the immobilized metal-acetylacetonate complexes are stable under the present reaction conditions.

High Selective Oxidation of Alcohols Based on Trivalent Ion (Cr3+ and Co3+) Complexes Anchored on MCM-41 as Heterogeneous Catalysts

Abdollah Fallah Shojaei,Mahboubeh Delavar Rafie,Mohammad Hassan Loghmani 대한화학회 2012 Bulletin of the Korean Chemical Society Vol.33 No.8

Cr(III) and Co(III) complexes with acetylacetonate were anchored onto a mesoporous MCM-41 through Schiff condensation. The materials were characterized by XRD, FT-IR, BET, CHN and ICP techniques. Elemental analysis of samples revealed that one C=N bond was formed through Schiff condensation on MCM-41 surface. The catalysts were tested for the alcohol oxidations using t-butyl hydroperoxide (TBHP) and H2O2 as oxidant. The catalytic experiments were carried out at both room temperature and reflux condition. Various solvents such as dichloromethane, acetonitrile and water were examined in the oxidation of alcohols. Among the different solvents, catalytic activity is found more in acetonitrile. Further, the catalysts were recycled three times in the oxidation of alcohols and no major change in the conversion and selectivity is observed, which shows that the immobilized metal- acetylacetonate complexes are stable under the present reaction conditions.