ARPN Journal of Engineering and Applied Sciences                         ISSN 1819-6608
 
 
 

 
ARPN Journal of Engineering and Applied Sciences                  June  2006  | Vol.1  No. 1

 
Title:

Effect of Cryogenic Cooling by Liquid Nitrogen Jet on Tool Wear and Product Quality in Turning AISI-9310 Steel

Author (s):

N. R. Dhar and S. Islam

Abstract:

Growing demand for higher material removal rate (MRR) in machining necessitated much increase in cutting velocity, which eventually required the efficiency of cooling to be increased in order to cope with the increase in the cutting temperature. Cryogenic cooling by liquid nitrogen jet is a promising new technology in high production machining which economically addressed the current process environmental and health concern. High production and finish machining are inherently associated with generation of intense heat and cutting temperature at the cutting zone. Such high cutting temperature not only reduces tool life but also impairs the surface integrity of the job. So the temperature at the cutting tool interface is one of the important factors influencing the machining process while primarily dependent on the cutting speed and the work piece material properties as well as cutting tool performance. The present paper deals with experimental investigation in the role of cryogenic cooling by liquid nitrogen jet on cutting temperature, tool wear, surface finish and dimensional deviation in turning of AISI 9310 steel by coated carbide insert (SNMG). The results have been compared with dry machining. The results of the present work indicate substantial reduction in tool wear, which enhanced the tool life, dimensional accuracy and surface finish. This may be mainly attributed to reduction in cutting zone temperature and favorable change in the chip‑tool interaction.

 
 
 
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Title:
An Elementary model to study sensitivity of the departure from Nucleate Boiling Ratio (DNBR) to perturbations in Nuclear Reactor Systems
Author (s):

Zafar-Ullah Koreshi

Abstract:

The heat flux in a water-cooled nuclear reactor system is used to estimate the Departure from Nucleate Boiling Ratio (DNBR) of the system which is an important engineering design parameter for nuclear reactors. The DNBR signifies an operational safety limit. During normal operation, there may be fluctuations in, for example, the power of the reactor, which can affect the temperature distribution along a coolant channel which may subsequently result in boiling leading to a reduction in heat transfer. This may further cause variations in the DNBR, which may reduce the safety margin requiring immediate remedial action. This work quantifies the sensitivity of the DNBR, and the location of the minimum DNBR due to power fluctuations obtained from a steady-state energy balance using radial heat conduction and convection. Results are presented for a reference PWR of 1893 MW(th). A future study will use the same analysis for the 300 MW(e) Chashma Nuclear Power Plant (Chasnupp).

 
 
 
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Title:

FATIGUE PROPERTIES OF SMOOTH AND AS-SHOT PEENED N BEARING AUSTENITIC STAINLESS STEELUNDER TENSION-TENSION CONDITION

Author (s):

A. Onizawa, M.A. Islam, M. Ojima and Y. Tomota

Abstract:

The fatigue properties of solution treated (ST) high nitrogen austenitic stainless steel (RS561) have been compared with a commercially available standard austenitic stainless steel (SUS310S) before and after shot peening. For doing this tension-tension fatigue tests were carried out at 5Hz and 22Hz frequencies at room temperature in air. In order to know the shot peening effects, half of the specimens of both steels were shot peened (SP). As per the experimental results, addition of nitrogen significantly improves the fatigue life and changes the fatigue fracture morphologies of the stainless steel, whereas frequency was found to have no marked effect on the fatigue lives. Shot peening have been found to increase the fatigue limits and change the fracture mechanisms of both steels. However, the increase in the fatigue limit in high nitrogen steel is much lower than that of the SUS310S steel. At high applied stress levels, effect of shot peening was found to disappear for both steels.

 
 
 
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Title:
Design and Calibration of a Direct Mounted Strain Gauged Lower Links System for Measurement of Tractor-Implement Forces
Author (s): R.J. Godwin, J. Kilgour, B.S. Blackmore
Abstract:

A bi-axial direct mounted strain gauged lower links system for the measurement of tractor-implement forces was designed and calibrated for coincident and perpendicular loads up to 10 kN. The system was tested for its Sensitivity, Cross-Sensitivity, Hysteresis, Linearity and Repeatability. The results of the calibration tests revealed that the system was well working for a range of draught and vertical forces up to 20 kN. The results showed a high degree of linearity between bridge output voltage and force applied. The minimum co-efficient of correlation, R2, was found to be 0.9996. The hysteresis effect between the calibration curves for increasing and decreasing applied coincident and perpendicular force was very small (<1.20%). The interactions of the applied forces on the orthogonal force bridges were less than one percent. Maximum difference from the mean value for applied coincident and perpendicular force respectively was 1.75% and 1.3%. The system could best be used for the measurement of draught (horizontal) and vertical forces where medium type equipment is attached with a tractor.

 
 
 
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Title:

Design of a Low Cost Multi Channel Data Logger

Author (s):

Sumon Saha, Md. Tofiqul Islam and M Zakir Hossain

Abstract:

Development of a low-cost multi-channel (eight to twenty two channels) data logger can easily be made and easily be used to convert the analog signal of physical parameters of various tests or other purposes of engineering. By a suitable program code it can be used to read the value digitally with a PC. Our aim is to provide with a module and a software package when installed in a computer, one can remotely acquire and monitor several numbers of the same or different types of signals sequentially at a time.  Signals obtained from various sensors have been effectively conditioned. Now interfacing these signals using an ADC with the parallel port of a computer satisfies the very goal of data acquisition. The user friendliness and reliability in using a PC and channel selector multiplexers further add to the versatility of the data logger. Design and implementation of such equipment cost only at US$30, makes it very inexpensive comparative to other commercially available data loggers.

 
 
 
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Title:

STUDY ON CONNECTION BETWEEN PRECAST CONCRETE BEAM AND CAST-IN-SITU COLUMN IN PREFABRICATED BUILDING FRAMES

Author (s):

Tazeen Fatema and Md. Toihidul Islam

Abstract:

As a structural system prefabrication is very efficient in terms of cost, time and quality, but suffers a major setback in connection, which is an important design and construction factor. A mathematical model capable of analyzing multistoried building frames incorporating semi-rigid beam-column connections has been developed. The model is linear type and iterative in nature developed for multistoried building frames with connection, which is based on maximum end moment of frame. A mathematical relationship is developed and used for analysis and design of joints of a particular type. The linear moment-curvature (M-θ) relationship for this particular type of connection has been formulated by using elementary solid mechanics. Using this relationship investigations have been carried out to study the behavior of precast building frame such as connection flexibility and its effect on internal distribution of forces, lateral drift, joint rotation etc. A parametric study with the connection is also carried out.  Finally a tentative recommendation regarding the use of the particular type of joint between precast beam and cast-in-situ column is made.

 
 
 
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Title:

CRITICAL ASSESSMENT OF THE DEGREE OF TEMPER EMBRITTLEMENT IN 2.25Cr-1Mo STEEL

Author (s):

M.A. Islam

Abstract:

Reversible temper embrittlement has been frequently observed in many different low alloy steels, serving at high temperatures, due to segregation of trace elements at grain boundaries and/or carbide/matrix interfaces. This type of impurity element segregation can severely deteriorate the toughness and fatigue properties of the steel. In general, increase in the hardness and tensile strength also increases the fatigue life of the steel. So, fatigue lives of steels are sometimes assessed by these parameters. In this research work 2.25Cr-1Mo steel, before and after temper embrittlement, was characterized by microstructure observation, hardness measurement, tensile, fatigue and fracture toughness tests at room temperature in air. Experimental results revealed that temper embrittlement hardly modify the room temperature hardness values and tensile properties, although the fatigue and fracture behaviours of this steel are significantly changed.

 
 
 
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Title:

Formulation of a General Risk Assessment Framework for the Water Related Disasters of Bangladesh

Author (s):

Rezaul Kabir Chowdhury

Abstract:

Bangladesh is a disaster prone area. Most of the disasters are water related such as flood, drought and water scarcity, cyclonic storm surge and river erosion. Almost every year the country faces severe catastrophic natural hazards. Risk assessment plays a vital role for planning proper risk reduction measures. Currently, the country has no risk assessment framework that provides a basic guideline for risk assessment to the planners and policy makers. In this study, a general risk assessment framework has been developed for the country.  Various steps of risk assessment and options of risk reduction have also delineated in the paper.

 
 
 
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