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Abstract

Nozzle hole diameter of 3D printer (3DP) can be varied to obtain required product quality as well as to reduce manufacturing times. The use of larger diameter may accelerate manufacturing times of products, yet the product quality, including the mechanical properties, still needs to be investigated profoundly. The purpose of this work is to investigate experimentally the effect of nozzle hole diameter of 3DP to the surface quality, accuracy, and the strength of the product. The specimens were manufactured by fused deposition modelling (FDM) 3D printing using polylactic acid (PLA) as the filaments.Bed temperature, extruder temperature and printing speed were set to be 60C, 200C and 80 mm/s respectively. The thickness of each layer was set at the ratio of 20% to the nozzle hole diameter. Infill pattern was determined by using line type of 100%. Nozzle hole diameter of 0.3, 0.4, 0.5 and 0.6mmwas compared in thiswork. The results show that bigger nozzle hole diameter enhanced the density and tensile strength of the products thought it was not linearly correlation.

Abstract

The optimal design of a subsoiler implement is a complex work that includes optimal design, material properties, structural reliability, random variables, soil properties, soil tillage equipment, and optimum safety measures. The main objectives of this study were to design and simulate the deep placement fertilizer applicator (DPFA) by using the finite element method (FEM). FEM simulation software was used to select the optimum material properties and improve the safety factor by considering a range of loads on DPFA. Three applied forces in a static simulation (4500, 5000 and 6000 N) were considered as were three application depths of fertilizers (0.15, 0.20, and 0.25 m), to improve the safety measures of the design. The simulation results showed that the best material property for DPFA is the AISI 4135 QT carbon steel materials. This yields a high strength of 780MPa and an ultimate tensile strength of 950 MPa (Young’s Modulus of 207 GPa and with Poisson’s Ratio of 0.33). The static simulation for 6000 N shows that the DPFA model had a maximum stress and strain of 379.9 MPa and 25.6×10−4 mm/mm respectively, with a contact pressure of 207 MPa, and a maximum displacement of 3.1 mm. The study results can provide theoretical and technical support for the development of agricultural tools, especially for DPFA in selecting optimum material properties and improving safety factors.

Abstract

The current state and prospective of electric discharge methods of synthesis of carbon and metal–carbon nanomaterials (CNMs) in different areas of science, technology and industry are considered in the present paper. It was shown that as a result of electric discharge treatment of liquid hydrocarbons, the productivity of CNMs (namely, onion-like carbon, carbon nanotubes, carbon nanofibers and carbon thin films) in terms of the percentage of carbon, released from initial liquid as a nanomaterial, was 6.1% for pentane, 10.2% for hexane, 8.7% for cyclopentane, 14.4% for cyclohexane, 12.0% for benzene and 16.8% for kerosene. Component and phase composition of obtained products depends on the electrode material and composition of initial hydrocarbon liquid.

Abstract

This research aims to develop an integrated information system for pharmaceutical companies in Indonesia, which has separate business units in two different locations. An Integrated System is needed to provide the value of competence in the technology and information systems that companies use in their business processes. The development stage starts from the assessment and understanding of the current situation both in the business environment and the IS/IT environment. The business environment includes the internal business environment and external business environment.Similarly, the IS/IT environment which includes internal and external IS/IT environments. With a deep understanding of current conditions, it can be determined the Information System(IS) strategy, Information Technology(IT) strategy and future IS/IT strategies. This study reveals the following results: The absence of good system integration with the business units involved makes the company in a weak position. But in terms of opportunity is quite high so that the use of technology and information systems that fit business needs is recommended in this study. The results of this study recommends some applications that can solve problems commonly experienced by companies such as system integration and business process automation to achieve more efficient and effective business processes.

Abstract

Soft-contact of molten steel can be achieved by applying a high-frequency electromagnetic field above the mold of continuous casting, which can effectively eliminate surface defects and achieve billets with no cracks and no oscillation marks. It also has some influence on the mold flux. In this study, the effect of a high-frequency electromagnetic field (20 kHz) on a mold flux flow field was simulated using a finite element software, and the slag film was extracted using a slag film simulator. The effect of the high-frequency magnetic field on the microstructure of the mold flux was analyzed using X-ray diffraction, Raman spectroscopy, and mineral phase testing. The results show that the high-frequency electromagnetic field disrupts the orderly movement and increases the movement rate of the liquid flux. The precipitate phase of the slag film did not change, but the silicate dimer Q 1 decreased, the chain Q 2 increased, and the network degree was increased. The slag film structure changed from the original two-layer form of crystalline layer–glass layer into a three-layer form of crystal layer–glass layer–crystal, and the crystallization ratio increased by 35% on average. The grain-size melilite granularity was reduced from the original 0.12 to 0.005 mm.

Abstract

Integration of domain expertise and uncertainty processing is increasingly important in automation solutions which rely on data analytics and artificial intelligence. We need a level to assess what is approximately correct. Uncertainties of the inputs are taken into account by using fuzzy numbers as the inputs of different fuzzy and parametric systems. Nonlinear scaling functions (NSFs) integrate these solutions and make them easier to tune. Fuzzy rule-based systems are represented with scaled fuzzy inputs. Membership functions (MFs) can be developed from NSFs and existing MFs can be used in developing NSFs. Fuzzy set systems and linguistic equation (LE) systems become consistent within the limits of detail. In recursive analysis, both meanings and interactions on all levels can be tuned together with genetic algorithms. In applications, the modular overall system consists of similar subsystems, which are normally used, with extensions to fuzzy. The compact fuzzy modules can be developed for specific tasks which are combined within Cyber Physical Systems (CPS). Uncertainty processing is embedded in the recursive analysis. The fuzzy extensions provide a feasible way for the sensitivity analysis of the solution.

Abstract

Hierarchical structures have attracted considerable interest due to their super-oleophobic/super-hydrophobic behavior. However, it is rare to present a novel additive manufacturing (AM) approach to fabricate hierarchical metal structures (HMSs). A micro/nano mixture ink was deposited on a substrate and a laser was used to selectively scan the ink layer. A new layer of ink was deposited on the previous consolidation layer during manufacturing. The surfaces of the as-sintered HMSs exhibit inherently super-hydrophilic and super-oleophobic behavior with a 155° contact angle (CA) with oil. Furthermore, the HMSs were successfully turned into super-hydrophobic and super-oleophilic mode (with a 152° CA) after surface modification with a solvent-free, electrostatic polytetrafluoroethylene particle deposition. They can be used as oil/water separation media by the functional surfaces existing in the pore channels. The experimental study of HMSs shows an effective removal of oil contaminants from water. The developed process also possesses an advantage of AM of HMSs with complex shapes in ambient air under the protection of an organic ink. Importantly, the present approach could be extended to a vast number of HMSs, for the preparation of highly durable functional materials for various applications.

Abstract

Stainless steel has proved to be an important material to be used in a wide range of applications. For this reason, ensuring the durability of this alloy is essential. In this work, pitting corrosion behaviour of EN 1.4404 stainless steel is evaluated in marine environment in order to develop a model capable of predicting its pitting corrosion status by an automatic way. Although electrochemical techniques and microscopic analysis have been shown to be very useful tools for corrosion studies, these techniques may present some limitationus. With the aim to solve these drawbacks, a three-step model based on Artificial Neural Networks (ANNs) is proposed. The results reveal that the model can be used to predict pitting corrosion status of this alloy with satisfactory sensitivity and specificity with no need to resort to electrochemical tests or microscopic analysis. Therefore, the proposed model becomes a useful tool to predict the behaviour of the material against pitting corrosion in saline environment automatically.

Abstract

In the present study, aluminium metal matrix composites (AMMC’s) reinforced with boron carbide (B4C) and graphite (Gr) particles were prepared by stir casting method. Dry sliding wear behavior of developed composites was conducted on pin on disc apparatus with variation in sliding distance, applied load and sliding speed. Taguchi method was employed to optimize the data in a controlled way. Analysis of variance was employed to examine the wear behavior of base alloy (Al2219), mono (Al/B4C) and hybrid (Al/B4C/Gr) metal matrix composites. The correlations were established by linear regression models and validated using confirmation tests. The obtained results indicated that B4C content, sliding distance is highly affected by the dry sliding wear followed by sliding speed and applied load. The incorporation of B4C and Gr particles in aluminium improves the tribological characteristics. The SEM images of mono composite shows the deep grooves on worn surface. It demonstrates the signs of abrasive wear of mono composite. The hybrid composite exhibits excellent wear resistance when compared to mono composite and base alloy. The main reason of that is the Gr particles act as a solid lubricating material in the hybrid composite (Al/B4C/Gr).