Free Vibration Analysis of Fiber Metal Laminated Straight Beam
-
Sinan Maraş
,
Mustafa Yaman
Abstract
In recent years, studies on the development of new and advanced composite materials have been increasing. Among these new technological products, Fiber Metal Laminates (FML), and hybrid structures made of aluminium, carbon, glass or aramid fiber, are preferred especially in the aircraft industry due to their high performance. Therefore, free vibration analysis is necessary for the design process of such structures. In this study, the vibration characteristics of FML for clamped-free boundary conditions were investigated experimentally and numerically. Firstly, numerical results were obtained using Finite Element Method (FEM) and then these results were compared with the experimental results. It was seen that the numerical results were in good agreement with the experimental results. As the theoretical model was justified, the effects of various parameters such as number of layers, fiber orientations, and aluminium layer thickness on the in-plane vibration characteristics of the FML straight beam were analysed using FEM. Thus, most important parameters affecting the vibration characteristics of the hybrid structures were determined.
1 Introduction
Composite materials are widely used in aircraft, defense industry and similar areas because of their high strength, high rigidity, high fatigue strength, high wear resistance and good corrosion resistance. Materials such as aluminium alloys and fiber reinforced composites used in such structures have advantages and disadvantages relative to each other. Thanks to the developing technology, these two materials have been combined to form a hybrid structure. Fiber metal laminates (FML) are hybrid structures consisting of fiber-reinforced polymer matrix composite and different sheet metals. This combination of materials provides good properties of metals and fiber reinforced composite materials [1]. There are some studies on composites and FML materials in the open literature. The determination of the mechanical and dynamic properties of structures made of composite materials is of great importance [2,3]. Considering the studies of fiber-metal laminated composite beams, the damping ratio with the Young’s modulus is experimentally determined for the forced vibration condition [4]. The effects of the transverse shear deformation of the beams on the vibration characteristics were investigated by the Rayleigh-Ritz method. Effects of sheet thickness, fiber orientation, and plate aspect ratio on vibrational behavior were observed [5]. Based on the Timoshenko theory, the effects of length, depth, temperature field, geometric nonlinearity and transverse shear deformation on the nonlinear dynamic response of the beam were investigated [6]. Free vibration analysis of circular fiber metal composite plate with a central hole was studied depending on the theory of elasticity [7]. Some studies were performed on the free vibration of the FML circular cylindrical shells subjected to different boundary conditions [8-9]. Numerical and experimental vibration analysis of FML plates were examined. The effects of aspect ratio and boundary conditions on the natural frequencies of fiber metal laminated plates were investigated using the Finite Element Method (FEM) for numerical analysis [10]. Nonlinear vibration behaviour of fiber metal composite beams subjected to moving loads was carried out [11]. Free and forced vibrations of cracked FML carrying moving loads were studied. Numerical analysis was carried out using the modal expansion theory and Newmark method [12]. Dynamic progressive failure properties of glass fiber composite/aluminium hybrid laminates under low-velocity impact was investigated by FEM [13]. It was also seen that there are limited research studies in the literature on the vibrational analysis of FML straight beams numerically and experimentally. In the present study, numerical results were obtained using FEM and compared with the achieved experimental results to demonstrate the accuracy of the proposed model. The beam was modelled with the ANSYS simulation software. Natural frequency values and mode shapes were given in the graphical form.
2 Experimental Verification of the Numerical Model
In order to validate the accuracy and applicability of the proposed model, numerical results were compared with experimental results. The layered composites were produced by hot pressing at 120°C and under 3.92 kN forces which was applied to the sample for two hours. FML composites were produced with 6 and 8 layers. In addition, lower and upper layers of the composites were made of aluminium sheet while inner layers were composed of carbon prepregs. Experimental results were obtained with the PULSE vibration measurement system, which is a computer-based multichannel analysis system. The material properties of carbon-fiber prepregs were chosen to be as follows: modulus of elasticity (longitudinal and transverse respectively): E1 = E2 =65.7 GPa, modulus of elasticity (transverse): E3 =39.42 GPa, shear modulus: G12 = G23 = G13 = 31.55 GPa, poisson ratios: Ʋ12= Ʋ23= Ʋ13=0.041, density: ρ =1600 kg/m3 . The material properties of Al2024-T3 were taken as: modulus of elasticity: E =53 GPa, shear modulus: G =27.6 GPa, poisson ratio: Ʋ =0.33 and density: ρ =2850 kg/m3 . Geometrically, length and width of the beam are 165 mm, 25 mm, respectively. Thickness of aluminium sheets and carbon fiber prepregs are 0.3 mm and 0.275 mm, respectively. The beams have clamped-free boundary conditions. The natural frequencies (Nf ) were obtained from the ANSYS program. It can be seen from Table 1 that, the present results are in good agreement with the results of experiments obtained with PULSE vibration measurement system.
Comparison of Natural Frequencies of FML Straight Beam.
| Number of layers | Experimental | Analysis | Numerical | Analysis | |
|---|---|---|---|---|---|
| First mode (Hz) | Second mode (Hz) | First mode (Hz) | Second mode (Hz) | ||
| 6 | Nf | 56.5 | 343.5 | 53.8 | 336.75 |
| 8 | Nf | 73.5 | 452.6 | 74.17 | 464.14 |
3 Numerical Analysis
To study the vibration characteristics of FML straight beams the finite element technique was used. After the theoretical model was justified, for which the numerical results and mode shapes were given in Table 1 and Figure 4 respectively. The effects of various parameters such as number of layers, fiber orientations, and aluminium layer thickness on the in-plane vibration characteristics of the FML straight beam were analysed by using FEM. The beam was modelled as 12 layers consisting of Aluminium layer and Carbon / epoxy layers.
FML composite beam sample.
Mode shapes and their corresponding frequencies of the composite beam for the case A2.
Ethical approval: The conducted research is not related to either human or animal use.
4 Results and Discussion
In this study, four different groups depending on the number and location of Aluminium (Al) and carbon prepreg (C) have been produced and presented in Table 2. For the given lamination in group A, as the number of aluminium layers increases, the natural frequencies decrease which is contrary to expectations: as the number of aluminium layers increases, the real frequency is expected to decrease (Figure 2a). The reason is that as the number of aluminium layers increases, the effective stiffness and density of the composite beam increase. However, both the increment in density and the mass moment of inertia are more dominant than increment in the stiffness of the system.
Effect of (a) the number of aluminum layers (b) placing the aluminium layer from the outer layer to the inner layer on the natural frequencies of the composite beam.
The Configurtions of FML composite bearn having different layer sequences.
| Case | Configuration | Description |
|---|---|---|
| A1 | (C0 _C90 _ C0_C90 _C0 _ C90)s | In group A, the effect of the number of Al layer on the vibration behavior of the FML composite beam |
| A2 | (Al_ C90_C0_C90_C0_ C90)s | |
| A3 | (Al_ Al _ C0 _C90 _C0 _ C90)s | |
| A4 | (Al_ Al _ Al_ C90 _ C0 _C90)s | |
| A5 | (Al_ Al _ Al_ Al_ C0_ C90)s | |
| A6 | (Al _ Al _ Al_ Al_Al _ C90)s | |
| A7 | (Al_ Al_ Al _ Al _ Al _ Al)s | |
| B1 | (Al_C30_C60_C90_C120_ C150)s | In group B, Al one layer was moved from the outer surface to the center of the composite step one step and change in the composite beam was analyzed |
| B2 | (C30_Al_C60_C90_C120_ C150)s | |
| B3 | (C30_C60_Al_C90_C120_ C150)s | |
| B4 | (C30_C60_C90_Al_C120_ C150)s | |
| B5 | (C30_C60_C90_C120_Al _C150)s | |
| B6 | (C30_C60_C90_C120_C150 _Al)s | |
| C1 | (Al _5C0)s | In group C, the Al layers were placed on the outer surface of the laminated composite and the orientation of fibers were changed |
| C2 | (Al_5C15)s | |
| C3 | (Al_5C30)s | |
| C4 | (Al_5C45)s | |
| D1 | (C45_Al_Al_Al_Al_Al)s | Group D is similar to group B however, in group D carbon fiber layer with 45o degrees orientation was moved from outer surface to the center vibration behavior of the of the composite instead of Aluminum. |
| D2 | (Al_C45_Al_Al_Al_Al)s | |
| D3 | (Al_Al_C45_Al_Al_Al)s | |
| D4 | (Al_Al_Al_C45_Al_Al)s | |
| D5 | (Al_Al_Al_Al_C45_Al)s | |
| D6 | (Al_Al_Al_Al_Al_C45)s | |
| Al: Aluminium / Cα : Carbon prepreg / α : Fiber orientation angle | ||
Considering the operating frequency was near the real frequency of the aluminium-free beam; increasing the number of Aluminium layers would result in a safer design since the difference between the natural and operating frequency increases. In the group B, the natural frequencies increase when the position of Al layers change from surface towards mid-plane, due to the increase in effective thickness (Figure 2b). This was due to the fact that the lateral stiffness of the carbon-fiber prepregs was greater than the Al layers, and their effect on the natural frequency of the structure was increased by being embedded in the inner layers of the structure of aluminium layer. Another reason is that the Al layers have high density compared to carbon prepregs causing an increase in moment of inertia on the beam. The cases (C1, C2, C3, C4) have been investigated in order to compare the frequencies by changing the fiber orientation angle of prepregs between first and last Al plies (Figure 3a). It was also observed that, the natural frequencies change related with the variation in orientation angle of fibers. The values of natural frequency increase more and more by increasing fiber orientation angle from 0o to 45o with an increment of 15o due to the rise of the stiffness of the structure. Besides, as the carbon/epoxy layer is placed from the surface towards the middle plane, natural frequency values decrease.
Effect of (a) carbon fiber orientation angle (b) position of carbon/epoxy layer on natural frequencies of the composite beam.
The highest natural frequency value was obtained with the composite beam having a fiber orientation angle of 45o which was another important finding of the present study. In group D, the natural frequencies decrease when the position of prepreg layers change from surface towards mid-plane, due to the increase in effective thickness causing an increase in moment of inertia on the beam (Figure 3b).
5 Conclusion
The vibration properties of FML composite beam subjected to fixed-free boundary condition were studied numerically. In this investigation, four cases depending on the number and location of Al and prepreg have been investigated.
It was seen that, the natural frequencies decrease when the number of Al layers increase.
The natural frequencies increase when the position of Al layers changing from surface towards mid-plane.
It was also observed that, the natural frequencies change with a change in orientation angle of fibers.
The change in the position of prepreg layers from surface towards mid-plane result in the decrease in natural frequencies.
Conflict of interest: Authors state no conflict of interest.
References
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© 2018 Sinan Maraş et al., published by De Gruyter
This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.
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- Dynamic Changes of Secondary Metabolites and Antioxidant Activity of Ligustrum lucidum During Fruit Growth
- Studies on the flammability of polypropylene/ammonium polyphosphate and montmorillonite by using the cone calorimeter test
- DSC, FT-IR, NIR, NIR-PCA and NIR-ANOVA for determination of chemical stability of diuretic drugs: impact of excipients
- Antioxidant and Hepatoprotective Effects of Methanolic Extracts of Zilla spinosa and Hammada elegans Against Carbon Tetrachlorideinduced Hepatotoxicity in Rats
- Prunus cerasifera Ehrh. fabricated ZnO nano falcates and its photocatalytic and dose dependent in vitro bio-activity
- Organic biocides hosted in layered double hydroxides: enhancing antimicrobial activity
- Experimental study on the regulation of the cholinergic pathway in renal macrophages by microRNA-132 to alleviate inflammatory response
- Synthesis, characterization, in-vitro antimicrobial properties, molecular docking and DFT studies of 3-{(E)-[(4,6-dimethylpyrimidin-2-yl)imino]methyl} naphthalen-2-ol and Heteroleptic Mn(II), Co(II), Ni(II) and Zn(II) complexes
- M-Polynomials and Topological Indices of Dominating David Derived Networks
- Human Health Risk Assessment of Trace Metals in Surface Water Due to Leachate from the Municipal Dumpsite by Pollution Index: A Case Study from Ndawuse River, Abuja, Nigeria
- Analysis of Bowel Diseases from Blood Serum by Autofluorescence and Atomic Force Microscopy Techniques
- Hydrographic parameters and distribution of dissolved Cu, Ni, Zn and nutrients near Jeddah desalination plant
- Relationships between diatoms and environmental variables in industrial water biotopes of Trzuskawica S.A. (Poland)
- Optimum Conversion of Major Ginsenoside Rb1 to Minor Ginsenoside Rg3(S) by Pulsed Electric Field-Assisted Acid Hydrolysis Treatment
- Antioxidant, Anti-microbial Properties and Chemical Composition of Cumin Essential Oils Extracted by Three Methods
- Regulatory mechanism of ulinastatin on autophagy of macrophages and renal tubular epithelial cells
- Investigation of the sustained-release mechanism of hydroxypropyl methyl cellulose skeleton type Acipimox tablets
- Bio-accumulation of Polycyclic Aromatic Hydrocarbons in the Grey Mangrove (Avicennia marina) along Arabian Gulf, Saudi Coast
- Dynamic Change of Secondary Metabolites and spectrum-effect relationship of Malus halliana Koehne flowers during blooming
- Lipids constituents from Gardenia aqualla Stapf & Hutch
- Effect of using microwaves for catalysts preparation on the catalytic acetalization of glycerol with furfural to obtain fuel additives
- Effect of Humic Acid on the Degradation of Methylene Blue by Peroxymonosulfate
- Serum containing drugs of Gua Lou Xie Bai decoction (GLXB-D) can inhibit TGF-β1-Induced Epithelial to Mesenchymal Transition (EMT) in A549 Cells
- Antiulcer Activity of Different Extracts of Anvillea garcinii and Isolation of Two New Secondary Metabolites
- Analysis of Metabolites in Cabernet Sauvignon and Shiraz Dry Red Wines from Shanxi by 1H NMR Spectroscopy Combined with Pattern Recognition Analysis
- Can water temperature impact litter decomposition under pollution of copper and zinc mixture
- Released from ZrO2/SiO2 coating resveratrol inhibits senescence and oxidative stress of human adipose-derived stem cells (ASC)
- Validated thin-layer chromatographic method for alternative and simultaneous determination of two anti-gout agents in their fixed dose combinations
- Fast removal of pollutants from vehicle emissions during cold-start stage
- Review Article
- Catalytic activities of heterogeneous catalysts obtained by copolymerization of metal-containing 2-(acetoacetoxy)ethyl methacrylate
- Antibiotic Residue in the Aquatic Environment: Status in Africa
- Regular Articles
- Mercury fractionation in gypsum using temperature desorption and mass spectrometric detection
- Phytosynthetic Ag doped ZnO nanoparticles: Semiconducting green remediators
- Epithelial–Mesenchymal Transition Induced by SMAD4 Activation in Invasive Growth Hormone-Secreting Adenomas
- Physicochemical properties of stabilized sewage sludge admixtures by modified steel slag
- In Vitro Cytotoxic and Antiproliferative Activity of Cydonia oblonga flower petals, leaf and fruit pellet ethanolic extracts. Docking simulation of the active flavonoids on anti-apoptotic protein Bcl-2
- Synthesis and Characterization of Pd exchanged MMT Clay for Mizoroki-Heck Reaction
- A new selective, and sensitive method for the determination of lixivaptan, a vasopressin 2 (V2)-receptor antagonist, in mouse plasma and its application in a pharmacokinetic study
- Anti-EGFL7 antibodies inhibit rat prolactinoma MMQ cells proliferation and PRL secretion
- Density functional theory calculations, vibration spectral analysis and molecular docking of the antimicrobial agent 6-(1,3-benzodioxol-5-ylmethyl)-5-ethyl-2-{[2-(morpholin-4-yl)ethyl] sulfanyl}pyrimidin-4(3H)-one
- Effect of Nano Zeolite on the Transformation of Cadmium Speciation and Its Uptake by Tobacco in Cadmium-contaminated Soil
- Effects and Mechanisms of Jinniu Capsule on Methamphetamine-Induced Conditioned Place Preference in Rats
- Calculating the Degree-based Topological Indices of Dendrimers
- Efficient optimization and mineralization of UV absorbers: A comparative investigation with Fenton and UV/H2O2
- Metabolites of Tryptophane and Phenylalanine as Markers of Small Bowel Ischemia-Reperfusion Injury
- Adsorption and determination of polycyclic aromatic hydrocarbons in water through the aggregation of graphene oxide
- The role of NR2C2 in the prolactinomas
- Chromium removal from industrial wastewater using Phyllostachys pubescens biomass loaded Cu-S nanospheres
- Hydrotalcite Anchored Ruthenium Catalyst for CO2 Hydrogenation Reaction
- Preparation of Calcium Fluoride using Phosphogypsum by Orthogonal Experiment
- The mechanism of antibacterial activity of corylifolinin against three clinical bacteria from Psoralen corylifolia L
- 2-formyl-3,6-bis(hydroxymethyl)phenyl benzoate in Electrochemical Dry Cell
- Electro-photocatalytic degradation of amoxicillin using calcium titanate
- Effect of Malus halliana Koehne Polysaccharides on Functional Constipation
- Structural Properties and Nonlinear Optical Responses of Halogenated Compounds: A DFT Investigation on Molecular Modelling
- DMFDMA catalyzed synthesis of 2-((Dimethylamino)methylene)-3,4-dihydro-9-arylacridin-1(2H)-ones and their derivatives: in-vitro antifungal, antibacterial and antioxidant evaluations
- Production of Methanol as a Fuel Energy from CO2 Present in Polluted Seawater - A Photocatalytic Outlook
- Study of different extraction methods on finger print and fatty acid of raw beef fat using fourier transform infrared and gas chromatography-mass spectrometry
- Determination of trace fluoroquinolones in water solutions and in medicinal preparations by conventional and synchronous fluorescence spectrometry
- Extraction and determination of flavonoids in Carthamus tinctorius
- Therapeutic Application of Zinc and Vanadium Complexes against Diabetes Mellitus a Coronary Disease: A review
- Study of calcined eggshell as potential catalyst for biodiesel formation using used cooking oil
- Manganese oxalates - structure-based Insights
- Topological Indices of H-Naphtalenic Nanosheet
- Long-Term Dissolution of Glass Fibers in Water Described by Dissolving Cylinder Zero-Order Kinetic Model: Mass Loss and Radius Reduction
- Topological study of the para-line graphs of certain pentacene via topological indices
- A brief insight into the prediction of water vapor transmissibility in highly impermeable hybrid nanocomposites based on bromobutyl/epichlorohydrin rubber blends
- Comparative sulfite assay by voltammetry using Pt electrodes, photometry and titrimetry: Application to cider, vinegar and sugar analysis
- MicroRNA delivery mediated by PEGylated polyethylenimine for prostate cancer therapy
- Reversible Fluorescent Turn-on Sensors for Fe3+ based on a Receptor Composed of Tri-oxygen Atoms of Amide Groups in Water
- Sonocatalytic degradation of methyl orange in aqueous solution using Fe-doped TiO2 nanoparticles under mechanical agitation
- Hydrotalcite Anchored Ruthenium Catalyst for CO2 Hydrogenation Reaction
- Production and Analysis of Recycled Ammonium Perrhenate from CMSX-4 superalloys
- Topical Issue on Agriculture
- New phosphorus biofertilizers from renewable raw materials in the aspect of cadmium and lead contents in soil and plants
- Survey of content of cadmium, calcium, chromium, copper, iron, lead, magnesium, manganese, mercury, sodium and zinc in chamomile and green tea leaves by electrothermal or flame atomizer atomic absorption spectrometry
- Biogas digestate – benefits and risks for soil fertility and crop quality – an evaluation of grain maize response
- A numerical analysis of heat transfer in a cross-current heat exchanger with controlled and newly designed air flows
- Freshwater green macroalgae as a biosorbent of Cr(III) ions
- The main influencing factors of soil mechanical characteristics of the gravity erosion environment in the dry-hot valley of Jinsha river
- Free amino acids in Viola tricolor in relation to different habitat conditions
- The influence of filler amount on selected properties of new experimental resin dental composite
- Effect of poultry wastewater irrigation on nitrogen, phosphorus and carbon contents in farmland soil
- Response of spring wheat to NPK and S fertilization. The content and uptake of macronutrients and the value of ionic ratios
- The Effect of Macroalgal Extracts and Near Infrared Radiation on Germination of Soybean Seedlings: Preliminary Research Results
- Content of Zn, Cd and Pb in purple moor-grass in soils heavily contaminated with heavy metals around a zinc and lead ore tailing landfill
- Topical Issue on Research for Natural Bioactive Products
- Synthesis of (±)-3,4-dimethoxybenzyl-4-methyloctanoate as a novel internal standard for capsinoid determination by HPLC-ESI-MS/MS(QTOF)
- Repellent activity of monoterpenoid esters with neurotransmitter amino acids against yellow fever mosquito, Aedes aegypti
- Effect of Flammulina velutipes (golden needle mushroom, eno-kitake) polysaccharides on constipation
- Bioassay-directed fractionation of a blood coagulation factor Xa inhibitor, betulinic acid from Lycopus lucidus
- Antifungal and repellent activities of the essential oils from three aromatic herbs from western Himalaya
- Chemical composition and microbiological evaluation of essential oil from Hyssopus officinalis L. with white and pink flowers
- Bioassay-guided isolation and identification of Aedes aegypti larvicidal and biting deterrent compounds from Veratrum lobelianum
- α-Terpineol, a natural monoterpene: A review of its biological properties
- Utility of essential oils for development of host-based lures for Xyleborus glabratus (Coleoptera: Curculionidae: Scolytinae), vector of laurel wilt
- Phenolic composition and antioxidant potential of different organs of Kazakh Crataegus almaatensis Pojark: A comparison with the European Crataegus oxyacantha L. flowers
- Isolation of eudesmane type sesquiterpene ketone from Prangos heyniae H.Duman & M.F.Watson essential oil and mosquitocidal activity of the essential oils
- Comparative analysis of the polyphenols profiles and the antioxidant and cytotoxicity properties of various blue honeysuckle varieties
- Special Issue on ICCESEN 2017
- Modelling world energy security data from multinomial distribution by generalized linear model under different cumulative link functions
- Pine Cone and Boron Compounds Effect as Reinforcement on Mechanical and Flammability Properties of Polyester Composites
- Artificial Neural Network Modelling for Prediction of SNR Effected by Probe Properties on Ultrasonic Inspection of Austenitic Stainless Steel Weldments
- Calculation and 3D analyses of ERR in the band crack front contained in a rectangular plate made of multilayered material
- Improvement of fuel properties of biodiesel with bioadditive ethyl levulinate
- Properties of AlSi9Cu3 metal matrix micro and nano composites produced via stir casting
- Investigation of Antibacterial Properties of Ag Doped TiO2 Nanofibers Prepared by Electrospinning Process
- Modeling of Total Phenolic contents in Various Tea samples by Experimental Design Methods
- Nickel doping effect on the structural and optical properties of indium sulfide thin films by SILAR
- The effect mechanism of Ginnalin A as a homeopathic agent on various cancer cell lines
- Excitation functions of proton induced reactions of some radioisotopes used in medicine
- Oxide ionic conductivity and microstructures of Pr and Sm co-doped CeO2-based systems
- Rapid Synthesis of Metallic Reinforced in Situ Intermetallic Composites in Ti-Al-Nb System via Resistive Sintering
- Oxidation Behavior of NiCr/YSZ Thermal Barrier Coatings (TBCs)
- Clustering Analysis of Normal Strength Concretes Produced with Different Aggregate Types
- Magnetic Nano-Sized Solid Acid Catalyst Bearing Sulfonic Acid Groups for Biodiesel Synthesis
- The biological activities of Arabis alpina L. subsp. brevifolia (DC.) Cullen against food pathogens
- Humidity properties of Schiff base polymers
- Free Vibration Analysis of Fiber Metal Laminated Straight Beam
- Comparative study of in vitro antioxidant, acetylcholinesterase and butyrylcholinesterase activity of alfalfa (Medicago sativa L.) collected during different growth stages
- Isothermal Oxidation Behavior of Gadolinium Zirconate (Gd2Zr2O7) Thermal Barrier Coatings (TBCs) produced by Electron Beam Physical Vapor Deposition (EB-PVD) technique
- Optimization of Adsorption Parameters for Ultra-Fine Calcite Using a Box-Behnken Experimental Design
- The Microstructural Investigation of Vermiculite-Infiltrated Electron Beam Physical Vapor Deposition Thermal Barrier Coatings
- Modelling Porosity Permeability of Ceramic Tiles using Fuzzy Taguchi Method
- Experimental and theoretical study of a novel naphthoquinone Schiff base
- Physicochemical properties of heat treated sille stone for ceramic industry
- Sand Dune Characterization for Preparing Metallurgical Grade Silicon
- Catalytic Applications of Large Pore Sulfonic Acid-Functionalized SBA-15 Mesoporous Silica for Esterification
- One-photon Absorption Characterizations, Dipole Polarizabilities and Second Hyperpolarizabilities of Chlorophyll a and Crocin
- The Optical and Crystallite Characterization of Bilayer TiO2 Films Coated on Different ITO layers
- Topical Issue on Bond Activation
- Metal-mediated reactions towards the synthesis of a novel deaminolysed bisurea, dicarbamolyamine
- The structure of ortho-(trifluoromethyl)phenol in comparison to its homologues – A combined experimental and theoretical study
- Heterogeneous catalysis with encapsulated haem and other synthetic porphyrins: Harnessing the power of porphyrins for oxidation reactions
- Recent Advances on Mechanistic Studies on C–H Activation Catalyzed by Base Metals
- Reactions of the organoplatinum complex [Pt(cod) (neoSi)Cl] (neoSi = trimethylsilylmethyl) with the non-coordinating anions SbF6– and BPh4–
- Erratum
- Investigation on Two Compounds of O, O’-dithiophosphate Derivatives as Corrosion Inhibitors for Q235 Steel in Hydrochloric Acid Solution
