P. K. Halder

Integrated manufacturing features and Design-for-manufacture guidelines for reducing product cost under CAD/CAM environment

The main contribution of the work is to develop an intelligent system for manufacturing features in the area of CAD/CAM. It brings the design and manufacturing phase together in design stage and provides an intelligent interface between design and manufacturing data by developing a library of features. The library is called manufacturing feature library which is linked with commercial CAD/CAM software package named Creo Elements/Pro by toolkit. Inside the library, manufacturing features are organised hierarchically. A systematic database system also have been developed and analysed for each feature consists of parameterised geometry, manufacturing information (including machine tool, cutting tools, cutting conditions, cutting fluids and recommended tolerances and surface finishing values, etc.), design limitations, functionality guidelines, and Design-for-manufacture guidelines. The approach has been applied in two case studies in which a rotational part (shaft) and a non-rotational part are designed through manufacturing features. Therefore, from manufacturing feature library a design can compose entirely in a bottom-up manner using manufacturable entities in the same way as they would be produced during the manufacturing phase. Upon insertion of a feature, the system ensures that no functionality or manufacturing guidelines are violated. The designers are warned if they attempt to include features that violate Design-for-manufacture and Design functionality guidelines. If a feature is modified, the system validates the feature by making sure that it remains consistent with its original functionality and Design-for-manufacture guidelines are re-applied. The system will be helped the process planner/manufacturing engineer by automatically creating work-piece data structure.

Solar Assisted Fast Pyrolysis: A Novel Approach of Renewable Energy Production

Biofuel produced by fast pyrolysis from biomass is a promising candidate. The heart of the system is a reactor which is directly or indirectly heated to approximately 500°C by exhaust gases from a combustor that burns pyrolysis gas and some of the by-product char. In most of the cases, external biomass heater is used as heating source of the system while internal electrical heating is recently implemented as source of reactor heating. However, this heating system causes biomass or other conventional forms of fuel consumption to produce renewable energy and contributes to environmental pollution. In order to overcome these, the feasibility of incorporating solar energy with fast pyrolysis has been investigated. The main advantages of solar reactor heating include renewable source of energy, comparatively simpler devices, and no environmental pollution. A lab scale pyrolysis setup has been examined along with 1.2u2009m diameter parabolic reflector concentrator that provides hot exhaust gas up to 162°C. The study shows that about 32.4% carbon dioxide (CO2) emissions and almost one-third portion of fuel cost are reduced by incorporating solar heating system. Successful implementation of this proposed solar assisted pyrolysis would open a prospective window of renewable energy.

Utilization of Bio-Oil for Cooking and Lighting

Among the available alternative sources of energy in Bangladesh bio-oil is recognized to be a promising alternative energy source. Bio-oil can be extracted by pyrolysis as well as expelling or solvent extraction method. In these days bio-oil is merely used in vehicles and power plants after some up gradation. However, it is not used for domestic purposes like cooking and lighting due to its high density and viscosity. This paper outlines the design of a gravity stove to use high dense and viscous bio-oil for cooking purpose. For this, Pongamia pinnata (karanj) oil extracted by solvent extraction method is used as fuel fed under gravity force. Efficiency of gravity stove with high dense and viscous bio-oil (karanj) is 11.81% which of kerosene stove is 17.80% also the discharge of karanj oil through gravity stove is sufficient for continuous burning. Thus, bio-oil can be effective replacement of kerosene for domestic purposes.

Prospect of Pongamia pinnata (Karanja) in Bangladesh: A Sustainable Source of Liquid Fuel

Energy is the basic requirement for the existence of human being in today’s digital world. Indigenous energy of Bangladesh (especially natural gas and diesel) is basically used in power generation and depleting hastily to meet the increasing power demand. Therefore, special emphasis has been given to produce alternative liquid fuel worldwide to overcome the crisis of diesel. Pongamia pinnata (karanja) may be an emerging option for providing biooil for biodiesel production. Although karanja biooil has been used as a source of traditional medicines in Bangladesh, it can also be used for rural illumination. This paper outlines the medical and energy aspects of Pongamia pinnata. It has been assessed that Bangladesh can utilize about 128.95u2009PJ through Pongamia cultivation in unused lands. The paper reviews the potentiality of Pongamia pinnata as a source of biodiesel and its benefits in Bangladesh. The paper also revives that, about 0.52 million tons of biodiesel can be produced only utilizing the unused lands per year in sustainable basis as it reduces CO2, CO, HC, and NOx emission compared to pure diesel.

Ergonomic design of classroom furniture for university students of Bangladesh

The desk-and-chair and chair-with-mounted-desktop furniture are widely used in the classrooms of Bangladeshi universities. However, an anthropometric survey showed that the fixed-type and side-mounted-desktop-chair used by university students in Bangladesh were not manufactured according to ergonomic considerations. The study evaluated the potential mismatch between university classroom furniture dimensions and anthropometric characteristics of 500 Bangladeshi university students. Fifteen anthropometric measurements and nine dimensions from the existing classroom furniture were measured and then compared together to identify any potential mismatch between them. The paper showed the variation between the anthropometric measurements of students and the dimensions of existing furniture. The results indicated that the seat height of both desk-and-chair and side-mounted-desktop-chair was high, while the desk height of desk-and-chair was high and that of side-mounted desktop chair was low for the students. The paper also recommends the furniture dimensions for both types, which are ergonomically fit.

Perspectives of Biogas Conversion into Bio-CNG for Automobile Fuel in Bangladesh

The need for liquid and gaseous fuel for transportation application is growing very fast. This high consumption trend causes swift exhaustion of fossil fuel reserve as well as severe environment pollution. Biogas can be converted into various renewable automobile fuels such as bio-CNG, syngas, gasoline, and liquefied biogas. However, bio-CNG, a compressed biogas with high methane content, can be a promising candidate as vehicle fuel in replacement of conventional fuel to resolve this problem. This paper presents an overview of available liquid and gaseous fuel commonly used as transportation fuel in Bangladesh. The paper also illustrates the potential of bio-CNG conversion from biogas in Bangladesh. It is estimated that, in the fiscal year 2012-2013, the country had about 7.6775 billionu2009m3 biogas potential equivalent to 5.088 billionu2009m3 of bio-CNG. Bio-CNG is competitive to the conventional automobile fuels in terms of its properties, economy, and emission.

Static Anthropometric Characteristics of Bangladeshi Vehicle Driver: A Case Study

Background. Inappropriate design of sitting furniture and working equipment causes the serious musculoskeletal injuries and various pains as well as reducing working efficiency. Uncomfortable sitting posture in prolonged driving in Bangladesh is an issue to be solved immediately. Therefore, anthropometric databank of user population is significantly essential for the suitable dimensional design for avoiding these remarkable problems. Methods. This study analyses the anthropometric data of the Bangladeshi male vehicle driver aged between 30 and 60 years. A total of 210 Bangladeshi healthy drivers are considered for 15 anthropometric measurements and compared with the similar anthropometrics of other nationalities. Results. The mean stature and sitting height erect of Bangladeshi driver are 1645u2009mm and 843u2009mm, respectively. The mean of body mass index (BMI) of the drivers is 26.09u2009kg/m2, which indicates that the drivers are overweight. The mean stature of Bangladeshi driver is 17u2009mm shorter than the driver of Korea and 115u2009mm shorter than the driver of Iran. Conclusion. There are substantial differences between the body dimensions of Bangladeshi driver and similar dimensions of other countries. In comparison, Bangladeshi driver is found to be the shortest compared with the sample of other nationalities.

Fuel properties of pyrolytic tyre oil and its blends with diesel fuel - towards waste management

The non-biodegradable nature of scrap tyres makes it not suitable for landfills. In this study thermal pyrolysis of waste tyre samples was carried out in a semi batch reactor made up of stainless steel in our own laboratory. The physiochemical properties of tyre pyrolysis oil (TPO) had been studied by different analysis. The oil samples obtained from waste tyre is distilled and then mixing with common diesel oil were analysed according to their fuel properties, elemental analysis and functional groups presents. The products from the tyre pyrolysis are (33-39) wt. % char, (34-42) wt. % oil, and except are uncondensed gases. Almost 44.5% TPO can be distilled as fuel oil. The comparative study of physiochemical properties and Fourier transform infrared spectroscopy (FTIR) analysis of distilled tyre pyrolysis oil (DTPO) and diesel oil is also present in this paper. The blended oil (50% DTPO+ 50% diesel) shows almost similar properties with conventional diesel oil except flash point and fire point.