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.

Gross architecture of ovarian specimens from a southwest Nigerian tertiary healthcare facility

Background: The aim of our study is to describe the gross morphology of ovarian specimens and to see if some entities can be distinguished based on their gross morphology. Methods: We did a cross-sectional study of all ovarian specimen received by 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 (Five-year period). OAUTHC is situated in the southwestern part of Nigeria. Results: We examined 225 right ovarian specimens. Non- neoplastic lesions were the most common lesions of the right ovary accounting for 52 cases followed by malignant tumour accounting for 25 cases. We examined 233 specimens of the left ovary of which 133 were normal. Eighteen (72%) of malignant tumors of the left ovary had cystic cut surfaces. The spectrum of lesions of both ovaries has different average widest diameters with significant overlap in their distribution. Metastatic carcinoma is seen to involve both ovaries and found to mainly have a solid cut surface. We found that the average widest diameter of a normal left ovary is 3.6 cm while that of a normal right ovary is 4.9 cm. Conclusions: The ovarian lesions have different widest diameters and are usually larger than that of a normal ovary. Benign ovarian tumours are generally larger than their malignant counterparts but cannot be distinguished based on size alone. Metastatic carcinoma involved both ovaries and had a predominantly solid-cut surface. The normal left ovaries were smaller than the normal right ovaries

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

Production constraints of smallholder pig farms in agro-ecological zones of Mpumalanga, South Africa

South African pig sector is a contributor to the agricultural industry. A study was conducted to identify the production constraints and compare the management practices in smallholder pig farms in Mpumalanga, South Africa. A total of 220 selected smallholder pig farmers were interviewed. Smallholder pig farming was predominated by male (64 %), age above 50 years (54 %), black Africans (98.6 %), and three quarters of the smallholder farmers were poor to just below average. Majority (80 %) have no pig husbandry training, while only 33 % received assistance from government’s Agricultural Department. In terms of stock, mixed breeds (89 %) from exotic pigs were mostly kept and majority (87 %) of the farmers kept ≤10 sows in their herds. Many farmers (75 %) engaged in risky behavior of buying auctioned-sourced boars, free-range boars, and untested boars from neighbors and relatives. Few (17 %) farmers practiced vaccination and only 10 % kept farm records. Majority of the responses on pre-weaning mortality (50 %) and post-weaning mortality (90 %) were within acceptable range of 1–10 and 1– 5 % mortality rates, respectively. The lead causes of mortality were weak piglets and crushing (46 %), diarrhea (27 %), poor management knowledge (19 %), and malnutrition (16 %). Agricultural training and government incentives will facilitate improved productivity in smallholder pig farming.University of South Africahttp://link.springer.com/journal/112502018-01-30hb2016Production Animal StudiesVeterinary Tropical Disease