The Performance of Traditional contract procurement on Housing projects in Nigeria.

The traditional contract procurement has been widely criticized as an ineffective procurement method because it often involves time and cost overrun on construction projects. Yet the method is still being widely used in Nigeria most especially for the procurement of housing projects. It is suspected that this procurement method may not be ineffective in all cost categories of housing projects. Therefore time and cost performances of the procurement method on 57 housing projects of varying cost categories initiated by the Nigerian government between 1993 and 1999 were studied. The category of one to five million naira (US$1.00 ≈ 92 Nigerian Naira in 1999) showed the least time overrun of 18.98% while the highest time overrun of 99.64 % was shown in the five to ten million naira. The over ten million naira category had the least cost overrun of 9.13% while the highest cost overrun of 34.55 % was shown in the less than one million naira. The one to five million naira cost category exhibited weak correlation between time and cost overruns but the five million naira and above categories showed strong correlation. It was concluded that one to five million naira cost category is quite suitable for traditional contract procurement on housing projects in Nigeria

Central Nervous System Depressant Properties of Treculia africana Decne

The study was carried out to investigate the central nervous system activity of Treculia africana. The central nervous system depressant properties of Treculia africana were determined using: Novelty –Induced Rearing and Grooming, Locomotor activity, Ketamine-induced sleeping time and effect on rectal body temperature. The crude extract produced decrease in rearing, grooming and locomotor activity. It also potentiated ketamineinduced sleeping time and produced hypothermic effect in mice. The crude extract possessed sedative effect, which may be through increase in the activity of GABA in the brain

HISTOLOGICAL AND HISTOCHEMICAL OBSERVATIONS ON THE REPRODUCTIVE ORGANS OF Archachatina marginata ovum (GASTROPODA: ACHATINIDAE) AT DIFFERENT REPRODUCTIVE STATES

The histological and histochemical variation in association with morphological variation in the repro-ductive system of Archachatina marginata ovum was the target of this investigation. Forty- five snails were dissected and categorized into 5 different reproductive stages (low mating, high mating, high egg, gravid and post reproductive). The reproductive tracts which include: hermaphroditic duct, albu-men gland, spermoviduct and spermatheca and the ovotestis were processed for histological and histochemical staining. There were some variations in the architecture of the reproductive organs be-tween the active (high mating, high egg and gravid) and non active stages (low mating and post repro-ductive) states. The active states were generally associated with colloidal or granular secretions. Gly-cogen and alkaline phosphatase activities were associated together throughout the epithelium of the reproductive system of A. marginata ovum and they were more strongly indicated in tissues that are intimately connected to the growth and development of gametes. It was concluded that morphological variation in the secreting glands of the reproductive system of A. marginata ovum is closely associated with changes in the functional secretory activities of the glands

Melatonin enhanced the restoration of biochemical profile in chlorambucil treated-rats: examination of after-withdrawal effects of the drug

Background: In the wake of global prevalence of different types of cancer, the widespread use of chemotherapy poses threat to the integrity of the reproductive system. Although chlorambucil (Chrm) has anti-calcinogenic action, its administration has been associated with reproductive damage. Similar to chlorambucil, melatonin has anti-cancerous effect. Moreover, the hormone is claimed to protect the reproductive tissues from the insult of different disruptors of their functionality and histoarchitecture. Therefore, the present study investigated the effects of post-administration of melatonin in Chrm treated rats, with an interest in examining the after-withdrawal effects of the drug.Methods: Forty rats of ten animals per group were used for the study which lasted for six weeks. The control group received normal saline (vehicle; 0.1 ml/day, p.o.) for six weeks, while group 2 was administered saline for three weeks and then Chrm during the subsequent three weeks. However, in groups 3 and 4, Chrm was administered during the first three weeks; thereafter, they were administered saline and melatonin respectively during the subsequent three weeks. Chrm and melatonin were administered at 0.2 and 10 mg/kg b.w./day (p.o.) respectively.Results: The administration of Chrm significantly decreased gonadotrophin releasing hormone, follicle stimulating hormone, luteinising hormone, testosterone and antioxidant enzymes, but significantly elevated pro-oxidant and pro-inflammatory markers compared to the control group. Moreover, it was accompanied with selected significant alterations of semen parameters and lipid indices. However, restoration of baseline status of testosterone, catalase, total antioxidant capacity, malondialdehyde, lactate dehydrogenase, uric acid, sperm count, and free fatty acid was simply enhanced by the withdrawal of the drug, while that of gonadotrophin releasing hormone, testosterone, semen parameters, superoxide dismutase, catalase, c-reactive protein, lactate dehydrogenase, and high density lipoprotein cholesterol was facilitated by the administration of melatonin.Conclusion: The restoration of biochemical profile after chlorambucil treatment could be enhanced by the administration of melatonin.Keywords: chlorambucil; melatonin; reproduction; toxicit

Impact of Climate Change on the Design Parameters of Heating, Ventilation and Air Conditioning Systems for Manned Spacecraft

Climatic design information has been published for several locations in the world by American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) but there has not been data for Nigerian cities in these publications. Therefore, this study was embarked upon to bridge the gap in knowledge. The study of impact of climate change on the design parameters of Heating, Ventilation and Air Conditioning (HVAC) systems for spacecraft cabin environment is presented with particular focus on Ikeja-Lagos, Nigeria. Firstly, the characteristics climate parameters such as outdoor dry-bulb temperature, coincident wet-bulb temperature, relative humidity, pressures, air composition, among others as it affects manned spacecraft were discussed. The data for climatic parameters for Ikeja-Lagos, Nigeria, for a period of fifteen years (1995-2009) were obtained from Nigerian Meteorological Agency (NIMET), Oshodi-Lagos. Statistical data and Microsoft excel were used for evaluation of variation trends of the climate parameters for departure city. This is very important in determining thermal human comfort in spacecrafts on ascent. Results obtained from this study are hereby presented. The Ikeja-Lagos dry-bulb temperature average results obtained were 33.81°C, 32.98°C, 32.3°C, 22.1°C, 21.19°C, 20.43°C, 23.84°C and 31.65oC.at 0.4%, 1.0%, 2.0%, 97.5%, 99.0%, 99.6%, median of extreme lows and median of extreme highs, respectively. The Ikeja-Lagos relative humidity average results were 116.3, 112.65, 109.14, 99.83 and 49.42 at 0.4%, 1% and 2.0% occurrence as well as at median of extreme highs and median of extreme lows, respectively. Ikeja-Lagos had mean coincident dry bulb temperature of 33.81°C and 32.98°C at 0.4% and 1% percentile respectively. The dry bulb temperature for Ikeja-Lagos was determined to be an average range from 20.43°C to 22.1°C between January to December, in the period of 1995-2009, at 97.5% 99% and 99.6% percentile respectively. These results provide values of design parameters which are useful in the design of HVAC for space crafts with climate change adequately taken into consideration as it applies to Ikeja-Lagos, Nigeri

An Evaluation of Traditional Contract Method on Residential Building Projects

In order of priority of basic human needs, housing is recognized worldwide as second ·to food and comes before clothing. This high priority coupled with United Nations aggressive campaign for adequate shelter for all citizenry has forced governments of nations to embark on direct construction of housing units for their people. In Nigeria, government direct intervention in housing delivery to the masses took the form of traditional contract procurement. This paper reports the result of a survey carried out to know the performance of this procurement method in relation to time and cost overrun. Valid data from fifty-seven residential projects ranging from one million to one hundred million Naira in itiated by government between 1993 and 1999 couple with questionnaires administered on Clients, consultants and contractors were used for the analysis was to establish whether there is significant difference between the mean time overruns and the mean cost overruns of traditional contract on residential projects of different cost categories. The result showed that the traditional contract performs better in terms of time overruns (18.98%) when used to procure residential building projects of five million Naira and below. However the procurement method performs better in terms of cost overrun(9.13%) for projects above ten million Naira. Attempts were also made to know if a relationship exists between time and cost in each category

VoIP on 3GPP LTE Network: A Survey

As wireless access networks evolve towards an all-IP architecture, the principles of operations of communication services (specifically voice services), which have hitherto been circuit switched are being revisited. Voice over Internet Protocol (VoIP) has been identified as a solution and is potentially capable of completely replacing existing phone networks.  However, as opposed to circuit switching technology, the call quality obtained via packet switching through IP has not been encouraging due to certain issues. The increasing demands on data rates, mobility, coverage and better service quality, led to the evolution in Radio Access Technologies (RATs) to an era of last-mile fourth generation (4G) access technologies among which is Long Term Evolution (LTE). LTE is an all-IP network initially meant for carrying data only, while carriers would be able to support voice traffic either by utilizing 2G or 3G systems or by using VoIP. This paper seeks to describe all options for providing VoIP services as a method of voice transfer over the LTE network. Keywords: 4G, Circuit switching, Convergence, LTE, Packet switching, RAT, VoIP

A BINOMIAL MODEL APPROXIMATION FOR MULTIPLE TESTING

Multiple testing is associated with simultaneous testing of many hypotheses, and frequently calls for adjusting level of significance in some way that the probability of observing at least one significant result due to chance remains below the desired significance levels. This study developed a Binomial Model Approximations (BMA) method as an alternative to addressing the multiplicity problem associated with testing more than one hypothesis at a time. The proposed method has demonstrated capacity for controlling Type I Error Rate as sample size increases when compared with the existing Bonferroni and False Discovery Rate (FDR).     &nbsp

Development of water hyacinth briquetting machine

Briquetting technology is one of the renewable sources of energy that was developed to address problems concerning global warming, energy catastrophe, as well as solid waste management. Nigeria has abundant supplies of biomass resources and unrestricted solid waste, whose potentials are yet to be fully tapped for energy generation. It is, therefore, necessary to convert these waste into a product that will provide alternative energy to the people rather than constituting environmental problems. The study was undertaken to develop of hyacinth briquette machine and examine the properties of fuel briquettes produced from a mixture of waste paper (WP) and water hyacinth plant (WHP) using corn and cassava starch as a binder. WP from the academic environment and WHP harvested from the surface of fresh waters were used. Briquette machine was designed using a screw type extruder to convert the processed WHP and WP into solid briquette for domestic consumption. Samples of WHP was harvested, ground, dried and mixed with WP. The mixture was poured into a hopper. The physical and combustion properties of the briquette were determined at varying WHP and WP-binder ratios of 100:10, 100:15, 100:25, 100:30 and 100:45, 100:55 using corn starch as the binding agent. It was discovered that the binder ratio 100:25 demonstrated the most affirmative value of biomass energy than others. It was also observed that the cooking time for the briquette produced using WHP and WP was 40min/kg with SFC of 0.4kg/kg. The designed machine has production efficiency of 84% and also produced smoke-free WH briquettes with high resistance to mechanical action, better handling and efficient fuel characteristics for household use

Antimicrobial and toxic potential of aqueous extracts of Allium sativum, Hibiscus sabdariffa and Zingiber officinale in Wistar rats

AbstractAllium sativum, Hibiscus sabdariffa and Zingiber officinale are medicinal plants with wide use in traditional medicine; however, the increasing use of crude extracts for traditional medicine applications raises safety concerns. We made a preliminary determination of the phytochemical constituents and antimicrobial and safety profiles of aqueous extracts of A. sativum, H. sabdariffa and Z. officinale. The extracts were administered orally to Wistar rats for 30 days: a control group received distilled water, three groups received the three extract, and a fifth group received a combination of the three extracts. All three extracts, either individually or in combination, had antimicrobial activity, and all extracts influenced the activities of marker enzymes. The evidence lends credence to use of these plants in traditional medicine but also suggests the probable toxic potential of crude plant extracts