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The work presented in this paper describes the steady state analysis of a non-isolated and continuous conduction mode (CCM) operated three-level DC-DC converter with input boost power stage for achieving high static voltage gain. The proposed converter configuration is a double boost DC-DC conversion scheme. A boost power module consisting of a power switch, an inductor, a pre-charge diode, and a diode rectifier is introduced as the input stage in the conventional three-level DC-DC converter configuration to obtain the DC-DC converter topology suggested in this research work. The role of the input boost power stage is to extend the voltage gain of the conventional three-level boost converter. The proposed topology employs two power switches in addition to a boost power switch with simple control strategy so that the switching losses are reduced. The switches are subjected to low voltage and current stresses. The suggested non-isolated converter is operated under continuous inductor current mode in open loop configuration. The converter configuration has been simulated in MATLAB / SIMULINK platform. The input boost power stage receives a voltage of 24 V from a DC source. With low duty ratio (= 0.8) of the power switches, a DC voltage of around 208 V is obtained at the load end. The passive components of the converter are so designed that the filtering requirements on the DC output voltage and current waveforms are reduced. The voltage gain of the proposed converter is compared with that of the three-level boost converter without input boost power stage. The various modes of operation of the suggested converter are discussed with relevant equivalent circuits. The proposed system is validated using a developed hardware prototype model of 100 W converter with a low cost KA3525A PWM controller. Both simulation and prototype model results demonstrate that the proposed converter suits high voltage gain applications.

This work is focussed at studying the compression ratio (CR) effect on the operating characteristics of a diesel engine fuelled with  diesel (80%) and pyrolytic oil (20%) blend, derived from Bael de oiled cake at standard conditions. Engine was operated at three CR’s namely 18:1 (higher), 17.5:1 (standard) and 16:1 (lower). For the blended fuel operation at full load, the brake thermal efficiency (BTE) improved by 5% and brake specific energy consumption (BSEC) diminished by 3% as the CR increased from 17.5 to 18. At high CR, the carbon monoxide (CO) and unburnt hydrocarbon (HC) were lowered by 58.3% and 38.5% respectively for blended fuel when compared to diesel at peak load. The nitrogen oxides emission (NOx) increased by 25.7% for blended fuel at peak load and CR of 18:1. On the whole the experimental results suggest that optimum performance of the engine can be attained at CR 18:1.

This paper examines the feasibility of using friction surfacing to deposit Aluminum alloy AA6061 material over an AISI 1017 steel substrate.  Further, this work aims to identify the deposition speed settings that would improve the effectiveness of the process. Consumable AA6061-T6 rods were deposited at different combinations of rotational and travel speeds while maintaining the same axial pressing force. The experiment involved 12 speed combinations with 3 replicates from each combination. Quantitative and qualitative methods were used to evaluate speed effects on the overall deposition quality. The evaluation involved different quality indicators including deposition efficiency and stability, surface roughness, deposit hardness and microstructure. Analysis has shown that the rotational speed is the primary factor that significantly affects all of the studied indicators. The travel speed, on the other hand, was found to have significant effects only on deposition efficiency and material hardness.   

used as a nanofiller. The methods used to synthesis bentonite nanoparticles are ball mill and co-precipitation and modification with surfactant cetyltrimethylammonium bromide (CTAB). Likewise, the OPBA synthesis process with the ball mill process and co-precipitation. Characterization using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM), FTIR and X-ray fluorescence (XRF). The results of characterization using XRD showed a decrease in particle size in bentonite-OPBA nanocomposites. The SEM results show uniformity of particle size in Bentonite-OPBA nanocomposite. Meanwhile, the FTIR results showed absorption peaks indicating bonding in the nanocomposite, confirmed by XRF results. The XRF results show the content of SiO2 and Al2O3 in the nanocomposite so that it can be applied as a nanofiller.

Anti-corrosion susceptibility is one of the top criteria for selecting metallic materials for several industrial applications. This work studies the corrosion performance on an Al-7075 alloy obtained by Repetitive Corrugation and Straightening (RCS). This processing method generated a microstructure formed by randomly distributed micro-, submicro-, and nano- metric grain sizes. The samples exhibited a drop in corrosion resistance for a longer duration in the electrolyte and higher deformation. However, the samples processed by RCS showed better electrochemical stability in comparison with the non-deformed condition. The improvement of electrochemical stability could be associated with the particular microstructure generated during the RCS process.

This review article elucidates the application and viability of electromagnetic fields as therapy and rehabilitation method for the treatment of musculoskeletal pathologies. All studies were found in different databases such as Science Direct, Scielo, IEEE, ProQuest, Pubmed, among others, where the search for information contemplated a period of 5 years (2016-2020). Results evidenced that electromagnetic fields used to treat musculoskeletal conditions showed positive results and improvements in reducing chronic and acute pain in different musculoskeletal pathologies such as osteoarthritis, osteoporosis, nonunions, fractures, fibromyalgia, muscular system injuries, among others. It was possible to evidence that one of the most used magnetic treatments were pulsed electromagnetic fields, which have been implemented to treat joint, muscle and nervous diseases. Additionally, several devices to generate the magnetic stimulation have been designed with a therapeutic and rehabilitation approach, which elucidate the progress in the implementation and acceptance of this type of therapeutic alternatives to treat musculoskeletal conditions. Finally, magnetic stimulation has been also implemented to enhance biomaterials function, evidencing that scaffolds stimulated with electromagnetic fields improve musculoskeletal tissue regeneration.

Nowadays laser scanners play an important role in technology and research, when it comes to measure 3D coordinates physically and in real time of any object under observation. Laser scanners have to measure the 3D coordinates of these objects in shortest time and with the smallest measuring error. A novel laser scanner called Technical Vision System (TVS), which uses Dynamic Triangulation and DC motors, was developed and proven to represent a fast and reliable scanning system. Previous research used the step response of the TVS mechanical actuators (DC motors), which can overshoot if certain controller parameters of the closed-loop control are selected. If the overshoot is undesirable, a trade-off must be made between speed and overshoot of the step response. Thereby, present paper describes a new approach to control the actual angular position of the TVS DC motors using a trapezoidal profile for the DC Motor velocity. The DC motors step response is replaced by a trajectory response, which allows the reduction of the relative angular error of the DC motors shaft to a value less than or equal to 0.1 percent. Also, the design of the control system, to implement the trapezoidal trajectory profile for the DC motor velocity in practice, is described in detail.

Palm Oill Mill Effluent is biomass produced in mill from processing palm oil mill. In this research, the structure and particle size of nano carbon particle from palm oill mill effluent (POME) have been succesfully using hydrothermal method. The characterization structure and particle size conducted by XRD, PSA, FTIR and UV-Vis, respectively. The single crystal of carbon structures in all peaks and average crystal size of 30.58 nm confirmed from XRD analysis. Then, PSA analysis informed that average particle sizes of nano carbon from palm oill mill effluent of 1.153 nm. Both analysis of structure and particle size have indicating of nano size from carbon particle synthesize from palm oil mill effluent. FTIR spectrum confirming that functional groups indicate that nanocarbons have been found in POME samples with luminescence generated from the surface state. The POME solution has been successfully converted into nanocarbon in the presence of blue fluorescence under UV light and has light absorption in the UV region at a peak of ~300 nm based from UV-Vis results.

Gold mining in Colombia has produced wealth that has helped the social and economic development of the country. Studying its extraction process offers artisanal mining broad alternatives that are more profitable for its small-scale production. Through this research, the possibility is offered of extracting 93.10% of gold in 180 minutes from a refractory mineral of pyritic origin with economic and environmentally friendly techniques such as the use of pretreatment with microwave waves, exposing the mineral to 637ºC for a maximum time of 4 minutes, and the use of thiourea as leaching agent at concentrations of 0.1 M. When comparing gold extraction with thiourea without pretreatment, a low extraction percentage is shown, 19.98%. This microwave pretreatment process was carried out on a nickeliferous laterite mineral, however, the results were not as effective for the extraction of nickel, only 40.8% was obtained in 420 minutes, because the pretreatment with its exposure Microwaving was not efficient.

Purpose: To increase the understanding of the IoT by demonstrating its impacts and benefits on supply chain performance. Design/methodology/approach: System dynamic simulation modeling to estimate IoT impacts on supply chain performance, based on a previously proposed framework and its propositions. Findings: In general, simulation results show a positive impact on the supply chain activities where the propositions targeted. Specifically: P2: better decision-making. – The study case shows better asset utilization, and reduced shipping time. However, transportation costs increase because of the lack of a decision-making system. P3: enhanced supply chain connectivity/collaboration/integration. – The study case shows that benefits of supply chain integration through demand planning can be obtained. P5: reduced lead-time. – The study Case shows a reduced shipping time when location technology and when all technologies are combined. P6: better asset utilization. – The study Case shows a higher utilization factor, hinting a better asset utilization even without a decision-making system. Research limitations/implications: The models here presented are based on merged data from different sources: Primary and secondary sources, and estimates based on assumptions. The mere nature of the base-data limits the precision of results. Practical implications: The implementation of data collection or data transmission technologies alone is not sufficient to obtain full benefits. A decision-making processing system, that integrates the complete array of appropriated technologies, should also be implemented. This the underlying concept and the contribution of the IoT.