Energy consideration in machining operations - towards explanatory models for optimisation results

Part of: Seliger, Günther (Ed.): Innovative solutions : proceedings / 11th Global Conference on Sustainable Manufacturing, Berlin, Germany, 23rd - 25th September, 2013. - Berlin: Universitätsverlag der TU Berlin, 2013. - ISBN 978-3-7983-2609-5 (online). - http://nbn-resolving.de/urn:nbn:de:kobv:83-opus4-40276. - pp. 153–158.This paper reports the application of a systematic research methodology for uncovering the reasons behind results obtained when energy is considered in machining optimisation. A direct search optimisation method was used as a numerical experimentation rig to investigate the reasoning behind the results obtained in applying Taguchi methods and Genetic algorithm (GA). Representative data was extracted from validated machining science equations and studied using graphical multivariate data analysis. The results showed that over 80% of reduction in energy consumption could be achieved over the recommendations from machining handbooks. It was shown that energy was non-conflicting with the cost and time, but conflicting with quality factors such as surface roughness and technical factors such as power requirement and cutting force. These characteristics of the solutions can provide an explanative motif required for practitioners to trust and use the optimisation results

Fibroepithelial tumours of the breast seen in a tertiary health centre in southwestern Nigeria

Background: Fibroepithelial tumours of the breast are mainly fibroadenoma and phyllodes tumour. Our objective was to describe the clinical and pathological features of benign fibroepithelial tumours and then compare our findings with reports from other parts of the world. Methods: We carried out a retrospective study of all benign fibroepithelial tumours diagnosed in the Department of Morbid Anatomy and Forensic Medicine of Obafemi Awolowo University Teaching Hospitals Complex (OAUTHC), Ile-Ife, Nigeria from January 1, 2018 to December 31, 2022. Results: A total of 538 cases of fibroadenoma were seen during the study period. Only 486 cases met the inclusion criteria and were then subsequently studied. Right sided tumour mass is seen in 203 (41.8%) patients, left sided masses in 173 (35.6%) patients and bilateral masses in 96 (19.8%) patients.  The age of the patients ranges from 11 to 75 years. The average duration of symptoms is 16 months. The maximum length of fibroadenoma nodule ranges from 0.9cm to 15cm. The number of nodules seen in a patient range from 1 to 15. There is no association between the size of a fibroadenoma, number of the masses or the duration of symptoms before removal of the mass, and the age of the patient. Nineteen cases of phyllodes tumour were seen during the study period. Conclusions: Our study shows that fibroadenoma is the most common fibroepithelial tumour of the breast. A sizeable proportion of patients have bilateral tumours. Phyllodes tumour is much less common.

Comparative study of microwave assisted and conventional synthesis of novel 2-quinoxalinone3- hydrazone derivatives and its spectroscopic properties

A series of novel quinoxalin-2(1H)-one-3-hydrazone derivatives, 2a -8d were synthesized via condensation of 3-hydrazinoquinoxalin-2(1H)-one, 1, with the corresponding ketones under microwave irradiation. The microwave assisted reaction was remarkably successful and gave hydrazones in higher yield at less reaction time compared to conventional heating method. The chemical structures of the compounds prepared were confirmed by analytical and spectral data