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Brake Fault Diagnosis Through Machine Learning Approaches – A Review
Get PDFDiagnosis is the recognition of the nature and cause of a certain phenomenon. It is generally used to determine cause and effect of a problem. Machine fault diagnosis is a field of finding faults arising in machines. To identify the most probable faults leading to failure, many methods are used for data collection, including vibration monitoring, thermal imaging, oil particle analysis, etc. Then these data are processed using methods like spectral analysis, wavelet analysis, wavelet transform, short-term Fourier transform, high-resolution spectral analysis, waveform analysis, etc., The results of this analysis are used in a root cause failure analysis in order to determine the original cause of the fault. This paper presents a brief review about one such application known as machine learning for the brake fault diagnosis problems
Hydroxytyrosol as Active Ingredient in Poly(vinyl alcohol) Films for Food Packaging Applications
Get PDFHydroxytyrosol (HTyr), a biophenol found in extra-virgin olive oil or olive oil by-products, well known for its strong antioxidant activity, was used as active ingredient for poly(vinyl alcohol) (PVA) matrix to develop film formulations by solvent casting process. The effect of HTyr on the morphological, thermal stability, optical, mechanical and release properties of PVA were investigated, while water absorption capacity, migration with food stimulants, water vapor permeability and antioxidant properties were tested taking into account the final application as food packaging systems. Morphological investigations evidenced homogeneity of all PVA/HTyr films, while the presence of HTyr clearly accounted for an increase of the crystallinity degree of the polymer matrix and also for providing antioxidant activity of the final films. The successful development of novel, environmentally friendly, safe active food packaging materials as an alternative to that which is petroleum based represents solid ground for product improvement and future testing on food
Synthesis and Characterization of Interpenetrating Polymer Networks (IPNs) from Acrylated Soybean Oil a-Resorcylic Acid: Part 2. Thermo-Mechanical Properties and Linear Fracture Mechanics
Get PDFThe thermo-mechanical properties and linear fracture mechanics of acrylated soybean oil and the triglycidylated ether of α-resorcylic acid interpenetrated networks as a function of their weight composition are the focus of Part 2 of this article. Thermo-mechanical characterization showed that the obtained materials behave as thermoset amorphous polymers, and that both the modulus and glass transition are extremely dependent on the epoxy/acrylate weight ratio. Modulus values ranged from 0.7 to 3.3 GPa at 30 °C, and glass transition temperatures ranged from around 58 °C to approx. 130 °C. No synergistic effect on these two properties was observed. Interpenetrating networks containing equivalent weight proportions of the parent resins showed the highest fracture toughness of the series, exhibiting a KIc value of around 2.1 MPa·m1/2. The results showed that the KIc values did not increase as Mc increased, which seems to suggest that a different mechanism is responsible for the increase in the fracture toughness displayed by IPNs. Also, there seems to be an exponential-type increase in the fracture energy with the Mc1/2 for the materials containing the epoxy phase
Polycondensation Resins by Lignin Reaction with (Poly) amines
Get PDFThe reaction of a desulphurized kraft lignin with hexamethylene diamine as a model of a polyamine has been investigated. For this purpose, guaiacol was also used as a lignin model compound and treated under similar conditions. Solid state CP-MAS 13C NMR, FTIR and MALDI-TOF spectroscopy studies revealed that polycondensation compounds leading to resins were obtained by the reaction of the amines with the phenolic and aliphatic hydroxy groups of lignin. Simultaneously a second reaction leading to the formation of ionic bonds between the same groups occurred. These new reactions have been clearly shown to involve several phenolic and alcohol hydroxyl groups, as well as lignin units oligomerization, to form hardened resins
Experimental Investigation on Thermal Diffusion in Ternary Hydrocarbon Mixtures
Get PDFThe main goal of this study was to investigate the thermal diffusion in ternary hydrocarbon mixtures composed of 1, 2, 3, 4 Tetrahydronaphtalene (THN)-Isobutylbenzene (IBB)-Dodecane (C12) with mass fractions of 80/10/10, 70/10/20, and 60/10/30 at mean temperature of 25 °C. Optical interferometry technique with Mach-Zehnder arrangement was used to conduct the experiments. The mixture was placed in a convectionless cell which was heated from above. The results for the mixture with mass fraction of 80/10/10 were in a good agreement with the corresponding benchmark values. Finally, the Soret coefficient for the other two mixtures have been proposed
Forced and Natural Vibrations of an Orthotropic Pre-Stressed Rectangular Plate with Neighboring Two Cylindrical Cavities
Get PDFForced and natural vibrations of a rectangular pre-stressed orthotropic composite plate containing two neighboring cylindrical cavities whose cross sections are rectangular with rounded-off corners are investigated numerically. It is assumed that all the end surfaces of the rectangular pre-stressed composite plate are simply supported and subjected to a uniformly distributed normal time-harmonic force on the upper face plane. The considered problem is formulated within the Three-Dimensional Linearized Theory of Elastic Waves in Initially Stressed Bodies (TDLTEWISB). The influence of mechanical and geometrical parameters as well as the initial stresses and the effect of cylindrical cavities on the dynamical characteristics of the rectangular orthotropic composite plate are analyzed and discussed
Effect of Rotation on the Propagation of Waves in Hollow Poroelastic Circular Cylinder with Magnetic Field
Get PDFEmploying Biot’s theory of wave propagation in liquid saturated porous media, the effect of rotation and magnetic field on wave propagation in a hollow poroelastic circular of infinite extent are investigated. An exact closed form solution is presented. General frequency equations for propagation of poroelastic cylinder are obtained when the boundaries are stress free. The frequencies are calculated for poroelastic cylinder for different values of magnetic field and rotation. Numerical results are given and illustrated graphically. The results indicate that the effect of rotation, and magnetic field are very pronounced. Such a model would be useful in large-scale parametric studies of mechanical response
Nanobiodiversity: The Potential of Extracellular Nanostructures
Get PDFAs an outcome of millions of years of evolution, biological systems have developed different methods to interact with their surroundings. Many of these adaptations, such as secretions, light-interacting surfaces, biochemical active compounds, and many other survival strategies, are phenomena occurring at the nanometric scale. In this review, we describe how extracellular nanometric structures are responsible for manipulating energy and matter, creating some of the emergent properties of life. Iridescent colors in birds’ feathers, the manipulation of wettability of insects’ exoskeletons, the adhesive properties of nanopatterned secretions and the ability to polarize light are examples of the potential of extracellular nanostructures. We defined the study of extracellular nanostructures as “nanobiodiversity,” a unifying concept that emphasizes the inspiration that life at the nanoscale offers, not only for designing new materials, but also for its understanding
Tailoring the Properties of Thermoplastic Starch with Bamboo Powder and/or Hollow Glass Microspheres
Get PDFIn this study, bamboo powder and/or hollow glass microspheres were added to thermoplastic cassava starch in order to overcome its drawbacks. The composites were characterized by scanning electron microscopy (SEM), tensile testing, water contact angle measurement and X-ray diffractometry (XRD), in addition to their thermal properties. The mechanical strength of the composites showed a general decline with increasing bamboo powder content while the water contact angles increased up to 15% of bamboo powder content (% w/w dry starch). The addition of hollow glass microspheres provides an optimal balance between hydrophobicity and mechanical strength. The results pointed to improved properties that are expected to make thermoplastic starch more attractive and hence more competitive with synthetic polymers
Production of Polyhydroxybutyrate (PHB) by Bacillus megaterium DSM 32 from Residual Glycerol of the Bioenergy Industry
Get PDFBiodegradable polymers from renewable resources are generating growing interest in the plastic industry because they have properties similar to synthetic polymers. Polyhydroxyalkanoates, mainly polyhydroxybutyrate (PHB), have mechanical and physicochemical properties very similar to their synthetic counterparts. This work explores the use of residual glycerol from the bioenergy industry for the production of PHB by Bacillus megaterium DSM 32. The glycerol works as a source of carbon and energy. Raw glycerol was purified with sulfuric acid in order to neutralize saponified fatty acids. The purification process generated three different phases. One of the phases was the glycerol-rich layer; this layer was filtered and concentrated by vacuum distillation process. The purity of the glycerol was determined by thermogravimetric analysis (TGA). Additionally, the physicochemical properties, like viscosity, pH, ash content and density, were measured. The experiments were conducted in shake flasks at 30°C and 120 rpm. Different glycerol concentrations (20, 30, 40 g/L) were used to evaluate the influence of the initial concentration of glycerol on the biomass accumulation and biopolymer production. The purified glycerol obtained had a high purity (~ 89.5–92.13%); this material does not contain fatty acids, although it contains ~3.7% salts. The final PHB concentration obtained was 0.054 mg/mL