Optimization of Fire Emergency Preparedness in Underground Mining Environments: An Agent-Based Evacuation Approach

Underground mining environments present a complex interplay of thermal and non-thermal hazards, with fires constituting a significant risk due to the release of heat smoke from incomplete combustion. The propagation of these hazards through the ventilation networks underscores the critical need for understanding fire scenarios and their interaction with the underground environment. Existing knowledge regarding past mine fire disasters, and quantification of associated hazards and risks are insufficient for optimizing emergency evacuation strategies in the event of an underground fire emergency. This research endeavors to bridge this gap by developing advanced quantitative risk assessment and evacuation models tailored specifically for underground mine fires. The primary goal of this work is to establish a robust integrated system for evaluating and optimizing emergency evacuation strategies by leveraging the capabilities of computational fluid dynamics (CFD) and agent-based model (ABM) simulations. Furthermore, this study aims to investigate critical factors that significantly influence fire safety and emergency preparedness in underground mining environments. By identifying these critical factors, this work seeks to optimize the management of emergency evacuation plans, offering an enhanced fire safety solutions for underground mining environments -- Abstract, p. i

Stratigraphic Influence on Geotechnical Properties of Subgrade Soils along the Irrua-Auchi Road, South Eastern Nigeria

Geotechnical investigation of the Irrua – Auchi road was carried out to determine the engineering properties of the subgrade soils and evaluate the pavement conditions with a view to establishing the causes of failures along portions of the road. This involved a study of the route geology, measurement of pavement deflection using the Benkelman beam device and in-situ dry density test of the subgrade soils using the nuclear gauge. Other tests included the routine geotechnical laboratory tests to determine index properties, compaction and CBR characteristics of the subgrade soils. Results indicated that the road traversed terrain underlain by the Ajali sandstone, the Imo shale and the Ameki Formations. The subgrade soils, composed mainly of fine grained materials classified as  A-4 to A-2-4., were  characterized by  plasticity index  of  4 -19%,  MDD  of 1.83 – 1.92 Mg/m3, 48- hour soaked CBR of 0.86 to 1.12 to show the fairly similar geotechnical properties of the soils. The segment of the road underlain by the Ajali derived soils was characterized by average relative compaction of 0.96 and average deflection of 0.26 mm and is classified as stable. The segments underlain by the Ameki and the Imo shale derived soils were characterized by average relative compaction of 0.89 and 0.88  and average pavement deflections of 0.39 mm and 0.61 mm respectively and are accordingly classified as less stable and least stable. Conclusively, in this study, the pavement deflections revealed pattern that reflect the influence of soil structures derived from stratification of the underlying geologic units. Keywords: key words, Subgrade soils, Engineering properties, Pavement deflection, Route geolog

Clinical Features and Pattern of Presentation of Breast Diseases in Surgical Outpatient Clinic of a Suburban Tertiary Hospital in South-West Nigeria

Objective: To characterize the clinical features and pattern of presentation of breast diseases as observed in our practice. Materials and Methods: A prospective study of 121 consecutive patients with breast complaints presenting in our Surgical Outpatient Clinics. The relevant data were collected by two surgeons using the prescribed forms and was analyzed using Epi Info 2003, Mann–Whitney (test of two groups) Chi-squared and Fishers exact test was used to compare parameters of benign and malignant groups. P value <0.05 was considered as significant. Results: One hundred and nineteen patients were females, two were males. The age range was 14–70 years. Forty two (34.7%) patients were in the 21–30 year age group. The commonest symptoms were breast lump in 111 (91.7%) patients, and breast pain in 28 (23.1%) patients. Breast pain was a significant presenting complaint in patients with breast malignancy (P=.026). On clinical examination 103 (85.1%) patients had palpable lumps, and seven patients were normal. Forty four patients (36.3%) had malignant disease, seventy patients (57.8%) had benign breast diseases and seven were normal. Fifty nine of the 70 benign diseases were fibroadenoma. One hundred and three patients (85%) had appropriate therapy, while 18 patients (14.8%), including eight with malignant disease absconded. Conclusion: In the study, a breast lump was the commonest clinical feature of breast disease. Over 60% of these were benign. Breast pain was a statistically significant presentation in patients with malignant breast disease. One in seven of the patients absconded.Keywords: Breast lumps, breast malignancy, breast pain, fibroadenomaNigerian Journal of Surgery, Jan-Jun 2012 | Volume 18 | Issue

Effect of Substitution of Bovine Rumen Epithelial Tissue Scrapings for Fishmeal on the Growth Performance, Nutrient Utilization and Carcass Characteristics of Broiler Chickens

Abstract. An eight-week feeding trial was conducted to evaluate the performance, nutrient utilization and carcass characteristics of broiler chickens fed varied levels of bovine rumen epithelial tissue scrapings (BRETS) in replacement for fish meal at 0, 50 and 100% levels of substitution. Fifty four birds were used for the study and the birds were randomly distributed into three (3) dietary treatments which were randomly assigned to the rations. Feed and water were supplied ad libitum and data were collected on the feed intake, weight gain, feed conversion ratio and nutrient utilization. Data were also collected on the carcass characteristics after some birds had been slaughtered at the end of the experiment. Data collected were subjected to one-way analysis of variance and significant differences were indicated using Duncan multiple range test to separate the means. Results indicated that there was significant difference (P0.05) in the weight gain, heart and lung weights. It was concluded that up to 50% BRETS inclusion as substitute for fish meal protein could be employed without any adverse effect, to maintain the quality of the broiler chicken while minimizing the high cost of whole fishmeal since BRETS is an abattoir by-product that is readily available locally. Keywords: Broiler chicken, epithelial tissue scrapings, fish meal, bovine rumen. Abstrak. Sebuah percobaan pakan selama delapan minggu dilakukan untuk mengevaluasi kinerja, pemanfaatan nutrisi dan karakteristik karkas ayam broiler yang diberi berbagai tingkat kerokan jaringan epitel (BRETS) rumen sapi sebagai pengganti tepung ikan pada 0 , 50 dan 100% tingkat substitusi. Lima puluh empat ayam broiler yang digunakan untuk penelitian dibagi secara acak ke dalam tiga (3) perlakuan pakan. Pakan dan air minum diberikan secara tak terbatas dan dicatat data konsumsi pakan, pertambahan bobot badan, rasio konversi pakan dan pemanfaatan nutrisi. Data lainnya yang diamati adalah karakteristik karkas setelah ayam dipotong pada akhir percobaan. Data yang dikumpulkan dianalisis dengan analisis ragam satu arah dan perbedaan nyata ditunjukkan dengan uji jarak berganda Duncan untuk memisahkan nilai tengah. Hasil penelitian menunjukkan bahwa ada perbedaan yang signifikan (P0,05) pada bobot badan, jantung dan bobot paru-paru. Disimpulkan bahwa pemberian BRETS hingga 50 % sebagai pengganti protein tepung ikan dapat digunakan tanpa efek samping, untuk menjaga kualitas ayam broiler sambil menekan biaya tepung ikan yang mahal karena BRETS adalah hasil samping rumah pemotongan hewan yang tersedia secara lokal. Kata kunci: Ayam broiler, kerokan jaringan epitel rumen sapi, tepung ikan,SA Salami et al./Animal Production 15(1):15-23, January 2013

Variation in Cassava Yield Cultivated on Ferralsols and Ferruginous Soils in Kwara State, Nigeria

Depleting soil fertility is a severe issue of cassava production, which is the chief source of dietary food energy for most people living in the lowland tropics and much of the sub-humid tropics of West and Central Africa. This study examined variation in cassava yield cultivated on ferralsols and ferruginous soils for five years from 2011 to 2015 in Kwara State, Nigeria. Primary and secondary data were used, and the collected data were analyzed using descriptive and inferential statistical methods. This study showed cassava yield under ferruginous soils was significantly higher than that of ferralsols (p<0.05). The mean values of total organic carbon, nitrogen and phosphorus content in the topsoil of ferralsols were 1.25, 0.127 and 1.558, respectively, while that of ferruginous soil were 2.192, 0.224 and 6.689, respectively. Further, the results showed that the values of nitrogen and potassium contents of ferralsols and ferruginous soils were remained within the range to support the optimum yield of cassava tuber. Findings also revealed that there could be a probable increase in the cassava yield production and a decrease in soil nutrients if farmers continue cultivating on both soils. This study recommends better practices of cassava cultivation on ferruginous soils, enlightenment on the appropriate soil management, and applying fertilizers to meet the increasing demand for cassava.    KEYWORDS:     Cassava Yield, Ferralsols, Ferruginous Soils, Kwara State, Variation, Nigeri

Mechanical Properties And Durability Performance Of POFA-Based Engineered Alkali-Activated Cementitious Composites

Palm oil fuel ash (POFA) has been partially used over the years in developing concrete and mortar. However, to save the environment of POFA waste from dumpsites causing health issues and to reduce the consumption of Portland cement, 100% POFA was used in this study. The properties and performance of POFA alkali-activated mortar and POFA engineered alkali-activated cementitious composite (POFA-EACC) have been studied. The aim of the research is to develop POFA-EACC with good mechanical strength and better matrix durability properties. This aim was achieved through the utilization of POFA as the only base material for the POFA-EACC. The study encompasses the suitability evaluation of POFA alkali-activated mortar matrix (without polyvinyl alcohol (PVA) fibers) for POFA-EACC, the durability performance of the alkali-activated mortar matrix and the composite mechanical performance of the POFA-EACC (with PVA fibers). The alkali-activated mortar mixtures were prepared with different NaOH molarities (10, 12 and 14M), Na2SiO3(NS)+NaOH(NH)/POFA ratios of 0.4, 0.5 and 0.6, NS/NH ratios of 2.5, 2, 1 and 0.5, constant sand/POFA ratio of 1.5 and 2% volume fraction for PVA fibres (for POFA-EACC) were used. The results revealed a huge potential in the use of POFA as base material for alkaline activation. The optimum mixture consists of design parameters: NS/NH = 2.5, (NS+NH)/POFA = 0.4 and NaOH molarity = 10M. The highest compressive strength of 23.47 MPa and approximately 25 MPa were recorded after just three days and 28 days of curing respectively. The developed POFA alkali-activated binder has as its main products, N-A-S-H gel with some C-(A)-S-H gel forming in tandem within the alkali-activated mortar microstructure. Attempt were also made to improve the compressive strength of low-alumina POFA alkali-activated binder through the addition of different percentages of Al(OH)3, but results showed some losses in strength. The compressive strength of the optimum mixture reduced from approximately 25 MPa to 18 MPa, the lowest with the Al(OH)3 addition. In addition, the POFA alkali-activated mortar performed excellently in durability with H2SO4 and MgSO4 exposures in comparison to Na2SO4, HCl and HNO3. The obtained results were in agreement with the SEM/EDS, XRD and FTIR analyses. In addition, the tensile and flexural properties of POFA-EACC is very much dependent on the properties of POFA alkali-activated mortar and the interfacial bond between the POFA mortar matrix and PVA fibres. The uniaxial compressive strength of POFA-EACC reduced in comparison with those without PVA fibers due to the fibre-POFA matrix interface weakness. Although the POFA-EACC showed appreciable ductility as revealed in the tensile strain capacity results, the ultimate tensile and first cracking strength is generally low. Generally, the mixture parameters especially the NaOH molarity and water content greatly influenced all the properties of the POFA-EACC

Comparative evaluation of processes for production of soybean meal for poultry feed in Nigeria Evaluación comparativa de procesos para la producción de harina de soya para la alimentación de pollos en Nigeria

This work examined and compared three processes for production of low trypsin inhibitor soybean meal. Soybean flour was subjected to roasting, autoclaving and steaming to denature trypsin inhibitors. Roasting was done at 120, 130, 135 and 140 ºC for 5, 7, 8 and 9 minutes, respectively. Autoclaving was carried out at 121ºC, 15psig for 20, 30, 40 and 50 minutes. Steaming was carried out at 105 ºC for 10, 12, 15 and 18 minutes. Defatting of the samples was done and the activity of trypsin inhibitor was investigated. Proximate analysis and quality tests was carried out to ascertain quality of the heat treated soybean meals. Trypsin inhibitor in the soybean meals from the three heat treatment processes ranged from 1.20 to 3.54mg/g while that of raw sample was 6.01mg/g. Percentage crude protein in all the heat treated samples ranged from 39.38 to 40.58 % while that of raw sample was 44.60 %. Urease index ranged from 0.11 to 2.07 % for all heat treated samples while it was 2.11 % for the raw samples. % KOH protein solubility in Soybean meal from the three processes ranged from 45.2 to 73.1 % while that of the raw sample was 49.1%. The results were statistically significant at p>0.05. At significance level of p>0.05 it was established that local soybeans can be processed with adequate heat to obtain low activity soybean meal with good nutrient standard. The steaming process operated at 105 ºC for 18 minutes gave the best overall results with trypsin inhibitor activity of 1.20 mg/g

Palliative surgery for cancer in southwest Nigeria

Background: Most patients with cancer in the low-income environment present late, when the chances of cure are remote. Palliative care which includes surgery is needed to improve quality of life and minimize suffering and emotional disturbances associated with end of life.Methodology: Retrospective study of palliative surgery cases over five years. Data extracted included demographic features, diagnosis, procedure carried out, clinical status at 30 days postoperative, and survival.Results: 1,581 patients were operated over the study period. 227 patients were operated for malignancies; of these 91 patients (40%) had palliative procedures. The diagnoses in palliative surgery cases: prostate cancer 50 patients (54.9%), breast cancer 14.3%, stomach cancer 9.9%, and others. Indications for surgery were: urinary bladder outlet obstruction 46.1%, pleural effusion 14.3 %, obstructive jaundice 13.2%, and others. Bilateral total orchidectomy was performed in 50.5%, tube thoracostomy in 14.3%, laparotomy and biopsy in 11%. Thirteen patients (14.3%) died postoperatively; 57 patients (62.6%) were alive and well at 30 days after surgery. Survival period was <1 to 53 months with a mean of 8 months.Conclusion: Palliative surgery is useful in some patients with cancer. Facilities for less invasive procedures should be improved.Keywords: Palliative surgery, Cancer, Outcom

Client perception of service quality at the outpatient clinics of a General hospital in Lagos, Nigeria

Introduction: service quality assessments have assumed increasing importance in the last two  decades. They are useful in identifying gaps in services been provided with the ultimate aim of guaranteeing quality assurance. The objective of this study was to assess the client perception of service quality at the outpatient clinics of Randle General hospital, Lagos.Methods: a descriptive cross sectional study was conducted from March to May 2013. A multistage  sampling technique was used to select respondents and data was collected with the aid of modified  SERVQUAL questionnaires. The data was analysed with aid of EPI-INFO 2002 and statistical significance was set at a P value 0.05 for statistical significance.Results: total of 400 respondents were interviewed. The mean age was 40 years with a standard  deviation of 15.2 yrs. The highest mean score of 4.35 out of a possible maximum of 5 was recorded in assurance domain while the lowest mean score of 4.00 was recorded in the responsiveness domain. The overall mean score of all the domains was 4.20 with standard deviation of 0.51. Overall majority (80.8%) of respondents rated the overall service quality as good/ very good. After linear regression, the assurance domain was the most important predictor of the overall perceived service quality (p< 0.001).Conclusion: the overall perceived service quality was good. The major deficiencies were in the  responsiveness domain and especially the waiting time. The hospital management should implement measures to improve the responsiveness of services by ensuring prompt delivery of services.Key words: Client perception, service quality, outpatient clinics

Effect of Substitution of Bovine Rumen Epithelial Tissue Scrapings for Fishmeal on the Growth Performance, Nutrient Utilization and Carcass Characteristics of Broiler Chickens

. An eight-week feeding trial was conducted to evaluate the performance, nutrient utilization and carcass characteristics of broiler chickens fed varied levels of bovine rumen epithelial tissue scrapings (BRETS) in replacement for fish meal at 0, 50 and 100% levels of substitution. Fifty four birds were used for the study and the birds were randomly distributed into three (3) dietary treatments which were randomly assigned to the rations. Feed and water were supplied ad libitum and data were collected on the feed intake, weight gain, feed conversion ratio and nutrient utilization. Data were also collected on the carcass characteristics after some birds had been slaughtered at the end of the experiment. Data collected were subjected to one-way analysis of variance and significant differences were indicated using Duncan multiple range test to separate the means. Results indicated that there was significant difference (P0.05) in the weight gain, heart and lung weights. It was concluded that up to 50% BRETS inclusion as substitute for fish meal protein could be employed without any adverse effect, to maintain the quality of the broiler chicken while minimizing the high cost of whole fishmeal since BRETS is an abattoir by-product that is readily available locally