Determination of energy consumption during turning of hardened stainless steel using resultant cutting force

Downsizing energy consumption during the machining of metals is vital for sustainable manufacturing. As a prerequisite, energy consumption should be determined, through direct or indirect measurement. The manufacturing process of interest is the finish turning which has been explored to generate (near) net shapes, particularly for hardened steels. In this paper, we propose using measured cutting forces to calculate the electrical energy consumption during the finish turning process of metals where typically the depth of cut is lower than the cutting tool nose radius. In this approach, the resultant cutting force should be used for calculating the energy consumption, instead of only the main (tangential) cutting force as used in the conventional approach. A case study was carried out where a hardened stainless steel (AISI 420, hardness of 47–48 HRC) was turned using a coated carbide tool, with a nose radius of 0.8 mm, without cutting fluid, and at 0.4 mm depth of cut. The experimental design varied the cutting speed (100, 130, and 170 m/min) and feed (0.10, 0.125, and 0.16 mm) while other parameters were kept constant. The results indicate that the electrical energy consumption during the particular dry turning of hardened steel can be calculated using cutting force data as proposed. This generally means machining studies that measure cutting forces can also present energy consumption during the finish or hard turning of metals, without specifically measuring the power consumption of the machining process. For this particular dry turning of hardened stainless steel, cutting parameters optimization in terms of machining responses (i.e., low surface roughness, long tool life, low cutting force, and low energy consumption) was also determined to provide an insight on how energy consumption can be integrated with other machining responses towards sustainable machining process of metals

Bacterial co-infections in a captive Python bivittatus with septicemia

This case reports bacterial co-infection in a dead albino python (Python bivittatus). The snake was brought in dead to the Universiti Veterinary Hospital, Universiti Putra Malaysia. Necropsy was conducted and organ samples were sent for virus and bacterial isolation, as well as histopathology. Gross pathological lesions include congestion of the heart, spleen and liver and presence of superficial whitish circumscribed spots in the lungs. Bacterial culture showed the presence of Salmonella enterica ssp arizona, Plesiomonas shigelloides and Enterobacter cloacae. Histopathological evaluation showed evidence of necrosis, degeneration and heterophil infiltration in the liver, kidney, heart and lungs. The snake was diagnosed to have died of bacterial septicemia

Application of Ikaz and direct quadrature for solving leakage in pipeline distribution by using transmission line modelling

A new transient-based advance towards single leak detection is proposed which requires a measurement station with an end at the pipe system. The method use the frequency response and gives adequate results using low frequency bandwidth. This research apply Empirical Mode Decomposition (EMD) as the method denoising the noisy pressure transient signal before the signal further analyze using instantaneous frequency analysis. Therefore EMD is the way to decompose into Intrinsic Mode Function (IMF) from the signal. However it is difficult to select suitable IMF. Thus the paper proposed the implementation of Integrated Kurtosis-based algorithm Z-filter technique for that allows automatic selection of relevant and appropriates IMF. This work demonstrated the synthetic pressure transient signal generates using transmission line modelling (TLM) in order to test the effectiveness of Ikaz as the autonomous selection of IMF. This paper implement the Direct Quadrature as the instantaneous frequency analysis. A straight fluid network was designed using TLM fixing with higher resistance at some point act as a leak and connecting to the pipe feature (junction, pipefitting or blockage). The analysis results using Ikaz revealed that the method can be utilized as an automatic selection of intrinsic mode function (IMF) although the noise level ratio of the signal is lower. Ikaz-kurtosis ratio is recommended and advised to be implemented as automatic selection of intrinsic mode function (IMF) through DQ analysis

Development of auditing in Malaysia: Legal, political and historical influences

This work investigates the role and contribution of external auditing as practised in the Malaysian society during the forty year period from independence in 1957 to just before the onset of the Asian Financial Crisis in 1997.It applies the political economic theory introduced by Tinker (1980) and refined by Cooper & Sherer (1984), which focuses on the social relations aspects of professional activity rather than economic forces alone.In a case study format where qualitative data was gathered mainly from primary and secondary source materials, the study found that the function of auditing in the Malaysian society in most cases is devoid of any essence of mission; instead it is created, shaped and transformed by the pressures which give rise to its development over time.The largely insignificant role that it serves is intertwined within the contexts in which it operates

Development of initial fuzzy expert system for machinability data

A machinability data base system, which forms a part of the common manufacturing data base and is also capable of adapting and optimizing the machining data, is an important component of automated manufacturing systems

Experimental investigation of multilayer coating performance on CBN cutting tools when turning of hardened AISI D2 cold work tool steel

A depth-graded multilayer coating is a multi-layer coating optimised for broadband response by varying the thickness of the layers used

Fabricating high mechanical strength gamma Fe2O3 nanoparticles filled poly(vinyl alcohol) nanofiber using electrospinning process potentially for tissue engineering scaffold

The use of electrospinning has gained substantial interest in the development of tissue engineering scaffolds due to its ability to produce nanoscale fibers which can mimic the geometry of extracellular tissues. Besides geometry, mechanical property is one of the main elements to be considered when developing tissue engineering scaffolds. In this study, the electrospinning process parameter settings were varied in order to find the optimum setting which can produce electrospun nanofibrous mats with good mechanical properties. Maghemite (γ-Fe 2 O 3 ) was mixed with poly(vinyl alcohol) and then electrospun to form nanofibers. The five input variable factors involved were nanoparticles content, voltage, flow rate, spinning distance, and rotating speed, while the response variable considered was Young's modulus. The performance of electrospinning process was systematically screened and optimized using response surface methodology. This work truly demonstrated the sequential nature of designed experimentation. Additionally, the application of various designs of experiment techniques and concepts was also demonstrated. Results revealed that electrospun nanofibrous mats with maximum Young's modulus (273.51 MPa) was obtained at optimum input settings: 9 v/v% nanoparticle content, 35 kV voltage, 2 mL/h volume flow rate, 8 cm spinning distance, and 3539 r/min of rotating speed. The model was verified successfully by performing confirmation experiments. The nanofibers characterization demonstrated that the nanoparticles were well dispersed inside the nanofibers, and it also showed that the presence of defects on the nanofibers can decrease their mechanical strength. The biocompatibility performance was also evaluated and it was proven that the presence of γ-Fe 2 O 3 enhanced the cell viability and cell growth rate. The developed poly(vinyl alcohol)/γ-Fe 2 O 3 electrospun nanofiber mat has a good potential for tissue engineering scaffolds

Machinability of Stainless Tool Steel using Nitrogen Oil-Mist coalant

For all dry machining process, temperature generated in the cutting zone is the major challenge. It causes tool failure and results in unsatisfactory surface finish. Application of flood coolant method during machining processes can significantly reduce the temperature and consequently extend the cutting tool life. However, it has serious concerns regarding environmental pollution, operator health and manufacturing cost. These issues are usually attempts to be overcame by using minimum quantity lubrication (MQL) technique. This method merges the advantages of both dry cutting and flood cooling by spraying a small amount of lubricant to the cutting zone using vegetable oil. In this paper, another technique is proposed in order to further enhance the machineability of the stainless tool steel (STAVAX ESR 48 HRC). This involves using of nitrogen gas (N2) and air as cooling medium in combination with oil mist lubricant (MQL). The results show that the combination between nitrogen and oil-mist lubricant much more prolonged the tool life and improved the surface finish than the air-oil mist lubricant medium

Does university students stress have an impact on their psychological well-being?

This study aimed to investigate the impact of stress on psychological wellbeing among the students from various faculties in Universiti Teknologi Malaysia. The questionnaire was administrated and was distributed to a sample of 368 students in the selected university. The findings illustrated that anxiety showed non-significant impact on psychological wellbeing. Depression and stress were instead found to have significant impact on the psychological wellbeing. In order to improve this phenomenon, it is highly recommended that university should take necessary proactive actions in helping students manage their mental health needs. Access to interventions and prevention programmes needs to be strengthened within the university settings