Optical properties of diamond like carbon films prepared by DC-PECVD

Diamond-like carbon (DLC) thin films were deposited at different substrate temperatures using methane and hydrogen gas in DC-PECVD at 2x10-1Torr. From the light transmission using UV-VIS spectroscopy it was found that the optical transition had changed from allowed indirect transition to allowed direct transition as the substrate temperature increased. The Optical gap increased with temperature, highest of 3.034 eV was observed at 573 K, beyond which it dropped. Colour of the film changed from light brownish to a colourless transparent film in the higher temperature. The Urbach energy decreased from 1.25 eV to 0.75 eV with increasing substrate temperature till 573 K and a slight increase after it. This trend is attributed to change in sp3/sp2 ratio or change in structure. The cluster size decreases with temperature, resulting in larger band gap and the structure more ordered. Similar pattern is also witnessed in the emission spectrum of the photoluminescence

Finite element based fatigue life prediction of cylinder head for two-stroke linear engine using stress-life approach

Abstract: This describes the finite element based fatigue life prediction of cylinder head for two-stroke linear engine subjected to variable amplitude loading applicable to electric power generation. A set of Al-alloys, cast iron and forged steel for cylinder head are considered in this study

In-cylinder heat transfer characteristics of hydrogen fueled engine: a steady state approach

Abstract: This study presents in-cylinder heat transfer characteristics of a single cylinder port injection Hydrogen fueled Internal Combustion Engine (H2ICE) using a steady state approach. Problem statement: The differences in characteristics between hydrogen and hydrocarbon fuels are led to the difference in the behavior of physical processes during engine cycle. One of these processes is the in-cylinder heat transfer. Approach: One dimensional gas dynamic model was used to describe the heat transfer characteristics of the engine. The engine speed was varied from 2000-5000 rpm, crank angle from -40° to +100°, while Air-Fuel Ratio (AFR) was changed from stoichiometric to lean limit. Results: The simulated results showed higher heat transfer rate but lower heat transfer to total fuel energy ratio with increasing the engine speed. The in-cylinder pressure and temperature were increased with decreasing AFR and increasing engine speed. The in-cylinder air flow rate was increased linearly with increasing engine speed as well as air fuel ratio. Conclusion/Recommendations: The results showed that the AFR has a vital effect on characteristics variation while the engine speed has minor effect. These results can be utilized for the study of combustion rocess, fuel consumption, emission production and engine performance

Throttling effect on the performance and emissions of a multi-cylinder gasoline fuelled spark ignition engine

The throttle mechanism, a regulatory technique of engine output, is accompanied by a loss of some energy. The effect of intake air throttling on the performance and emissions of a multi-cylinder spark ignition gasoline engine was experimentally investigated. The engine was coupled to a hydraulic dynamometer equipped with a customized cooling system for both the engine and dynamometer. Experimental tests were performed for various engine speeds and air-fuel ratios at the WOT and POT conditions with optimized ignition timing. The acquired results recorded that a better engine operation could be achieved with WOT in terms of bmep, bsfc, ηb, CO, CO2 and UHC compared to POT. At the same time, the worst trend at WOT was noticed for the NOx concentration due to the higher conversion efficiency of fuel combustion. In terms of engine speed for both WOT and POT conditions, operating at 3000 rpm represents the minima of ϕ, bsfc, CO and UHC; and the maxima of ηb, CO2 and NOx with some fluctuation on both sides of this point. Maximum recorded values of ηb were about 30.55% and 28. 55%, while the minimum values of bsfc were about 274 and 293 g/kW.h for the WOT and POT conditions, respectively. The maximum bmep was obtained at 2500 rpm at WOT and POT conditions with values of about 940 kPa and 904 kPa, respectively. Maximum recorded values of NOx were about 1525 and 977 ppm for the WOT and POT conditions, respectively

Performance Analysis of A Spark Ignition Engine Using Compressed Natural Gas (CNG) as Fuel

AbstractCompress natural gas (CNG) is also considered as alternative fuel to produce better emission in a vehicle, but the main disadvantage of CNG in comparison to liquid fuel (gasoline) is the lack of power produced for the same capacity of engine. In this study, the single cylinder spark ignition (SI) engine was selected in order to study the effect CNG into the spark ignition engine. The hydraulic dynamometer was used to study the performance of CNG and liquid fuel. The usage of sensor also applies to the test to extract the data during the ignition stage for liquid fuel and CNG. The heat generated by both types of fuel also had been extracted from the tested engine in order to define which usage of fuel would cause a higher heat transfer to the engine. From this study, the result showed that pressure inside cylinder for CNG is 20% less than gasoline. CNG fuel also produced 23% less heat transfer rate compared to gasoline. The results explained why CNG produced 18.5% lower power compared to liquid fuel (gasoline).So, some improvement needs to be done in order to use CNG as fuel

Gold-catalyzed growth of aluminium-doped zinc oxide nanorods by sputtering method

Aluminium-doped zinc oxide (AZO) nanorods thin films were grown by RFmagnetron sputtering on gold (Au) metal catalyst. The Au catalyst layers with 5, 10, and 15nm thickness were deposited on glass substrates by sputtering method followed by annealing for 15 min at 500∘C to form Au nanostructures on the glass substrate.The AZO thin films were then deposited on the Au catalyst at different deposition temperature varying from 200 to 500∘C. Postdeposition annealing processes of the Au catalyst resulted in different morphologies of the Au catalyst layers depending on their thicknesses. This in turn gave different AZO morphologies which suggest that the Au catalyst layer thickness and the deposition temperature contribute to the growthmechanism of the AZO nanostructures. AZO nanorods thin films having hexagonal wurtzite structure with individual nanorods on the film surface were obtained from the samples deposited on 5 and 10 nm thick Au catalyst with the deposition temperature of 300∘C

Thermal Analysis of Ventilated Disc Brake Rotor for UTeM Formula Varsity Race Car

A new design of disc brake using ventilated rotor was developed for the UTeM Formula Varsity racing car. Compacted graphite cast iron (CGI) was proposed as the material for the disc brake rotor. Thermal analysis was performed in this project to assess the component performance using ABAQUS/CAE v6.7-1 finite element analysis software both in transient condition. Results from the analysis show that the maximum temperature generated on the disc brake surface at the end of the braking procedure for transient condition was within the allowable service temperature of the ventilated rotor material. Thus, the new disc brake rotor is safe for operation and is expected to perform successfully as per design requirement

Application of comparative genomic hybridization and fluorescence in situ hybridization on human glioma cell lines treated with bis[S-methyl-β-N-(2-furylmethylketone) dithiocarbazato] cadmium(II)

Gliomas are the most common primary tumors which arise from cells of the brain itself rather than metastazing to the brain from another location in the body. It can be slow growing (low grade, grades 1 and 2) or rapidly growing (high grade, grades 3 and 4). For instance, diffuse and fibrillary astrocytomas are divided histopathologically into three grades of malignancy: World Health Organization (WHO) grade II astrocytomas, WHO grade III anaplastic astrocytoma and WHO grade IV glioblastoma multiforme (GBM) (Otto, 2001)

Performance Analysis Of A Spark Ignition Engine Using Compressed Natural Gas (CNG) As Fuel

Compress natural gas (CNG) is also considered as alternative fuel to produce better emission in a vehicle, but the main disadvantage of CNG in comparison to liquid fuel (gasoline) is the lack of power produced for the same capacity of engine. In this study, the single cylinder spark ignition (SI) engine was selected in order to study the effect CNG into the spark ignition engine. The hydraulic dynamometer was used to study the performance of CNG and liquid fuel. The usage of sensor also applies to the test to extract the data during the ignition stage for liquid fuel and CNG. The heat generated by both types of fuel also had been extracted from the tested engine in order to define which usage of fuel would cause a higher heat transfer to the engine. From this study, the result showed that pressure inside cylinder for CNG is 20% less than gasoline. CNG fuel also produced 23% less heat transfer rate compared to gasoline. The results explained why CNG produced 18.5% lower power compared to liquid fuel (gasoline).So, some improvement needs to be done in order to use CNG as fuel

Business analytics in industry 4.0: a systematic review

Recently, the term “Industry 4.0” has emerged to characterize several Information Technology and Communication (ICT) adoptions in production processes (e.g., Internet-of-Things, implementation of digital production support information technologies). Business Analytics is often used within the Industry 4.0, thus incorporating its data intelligence (e.g., statistical analysis, predictive modelling, optimization) expert system component. In this paper, we perform a Systematic Literature Review (SLR) on the usage of Business Analytics within the Industry 4.0 concept, covering a selection of 169 papers obtained from six major scientific publication sources from 2010 to March 2020. The selected papers were first classified in three major types, namely, Practical Application, Reviews and Framework Proposal. Then, we analysed with more detail the practical application studies which were further divided into three main categories of the Gartner analytical maturity model, Descriptive Analytics, Predictive Analytics and Prescriptive Analytics. In particular, we characterized the distinct analytics studies in terms of the industry application and data context used, impact (in terms of their Technology Readiness Level) and selected data modelling method. Our SLR analysis provides a mapping of how data-based Industry 4.0 expert systems are currently used, disclosing also research gaps and future research opportunities.The work of P. Cortez was supported by FCT - Fundação para a Ciência e Tecnologia within the R&D Units Project Scope: UIDB/00319/2020. We would like to thank to the three anonymous reviewers for their helpful suggestions