nigerian defence academy
journal of science and engineering (ajse)
PRELIMINARY PHYTOCHEMICAL AND ANTIMICROBIAL SCREENINGS OF THE LEAVES OF NEWBOULDIA LAEVIS
NSI, E.W. and YAJI, J.N.
The plant Newbouldia laevis is used in traditional medicine practices in treatment of malaria by the Tiv, Efik, and Igbo people of Nigeria. The preliminary phytochemical screening of the aqueous extract of the leaves of Newbouldia laevis carried out revealed the presence of saponins, tannins, steroids glycosides, reducing sugars, anthraquinones and flavonoids. Alkaloids were absent. Hexane and methanol extracts of the plant leave examined by TLC showed Rf values of the various components. None of the components of the leave extracts of this plant showed anti-microbial activities in this study. Further studies may need be done before definite conclusions on the ant-microbial.
SYNTHESIS AND FASTNESS PROPERTIES ON WOOL AND NYLON 6.6 SUBSTRATES OF ACID DYES DERIVED FROM P-AMINODTOLUENESULPHONE-N-ETHYLANILIDE
M.K. YAKUB, K.A. BELLO AND M.S. GUMEL
The synthesis, characterization and fastness properties of Monoazo acid dyes derived from p-amino-toluenesulphon-N-ethylanilide as diazo component is reported. The dyes produced were very bright in colours. It was however observed that dyes that were much affected by intramolecular interaction gave lower wavelengths of maximum absorptions. Whereas the dyes gave lower ratings with respect to wash fastness on wool than on nylon 6.6, the gave higher ratings of light fastness on wool. Dyes that exhibited greater intra molecular interactions prove superior to those that didn’t exhibit it, with respect to the fastness ratings.
MORPHOMETRIC ANALYSIS INVOLVING THREE POTATO
(Solanum tuberosum L.) COLTIVAR IN JOS
Morphological structures of three potato (Solanum tuberosum L.) cultivars (Diamant, Nicola and Rosli Ruaka) characterized in Jos with special attention to their water use efficiency status. Analysis of variance revealed that significant difference existed between diamante (regarded as water saver) and Roslin Ruaka (regarded as water spender). These differences included: growth in the shoot height, leaf area expansion, internodal length, petiolar lengths, and shoot: root rations. Although differences were also observed on other parameters such as stem girth, number of above-ground stems per stand, number of leaflets per leaf, and root length, these differences were statistically insignificant (P = 0.05). The third cultivar, Nicola, exhibited an intermediate response. This work provides a quantitative data-base upon which subsequent anatomical evaluations of tissues and tissue elements associated with water-relations of the three potato cultivars will be based.
POZZOLANIC PROPERTIES OF KATSI
S.P. EJEH and O.B. ELLA
Silicious or Silicious – Aluminous materials which in itself possess little or no cementitious value but which in finely divided form and in the presence of moisture, chemically react with calcium hydroxide at ordinary temperatures to form compounds possessing cementations properties are often referred to as pozzolanas. Katsi was investigated as a possible pozzolana. Physical as well as chemical tests were carried out on katsi and – cement mixture to determine the suitability of katsi as a possible pozzolana; when carefully mixed with cement paste. It is observed that the results obtained indicate that katsi is a pozzolanic material with pozzolanic Activity Index of 90 percent while the minimum required by Standard is 75 percent. The values of 1 hour and 13 hours are recommended for the initial setting time and final setting time respectively for katsi – cement pozzolanic cement.
ASSESSMENT OF ENGINEERING PROPERTIES OF PIGMENTED CONCRETE
USING LOCALLY SOURCED PRGMENTS
The study investigates the effect of pigments as a tinctorial source of colour concrete (colour-Crete) with the aim of assessing he dosage level required for an appreciable tinctorial strength for aesthetic purposes. The objective of the study is to produce an alternative to the usual practice of painting of concrete structures after rendering, by incorporating some percentage of colouring agent into the concrete, when it is plastic. Hence the need to assess the effect(s) of these colouring agents on the strength parameters of the concrete. Two locally sourced pigments were used. Their chemical analyses classify they as red oxide and carbon black compounds. These pigments were in powdery form and the percentage of the colouring agent added or incorporated was a fractional weight of the cement content in the mix as recommended in Bs 1014:1961. The percentage of the pigments incorporated varied from 0% to 6%. Nominal mix ratio of 1:2:4 and 1:2:4and ½: were chosen, with water cement ratio of 0.48 and 0.58 respectively. A total number of 192 specimens were produced consisting of 64 cubes, 64 cylinder and 64 miniature beams. The were tested at 28 day of cast using the destructive techniques. The results obtained show that with the increase in the percentage of pigment introduced into the concrete, there was negligible reduction in strength compared with the control specimen.
INHIBITION OF CORROSION OF MILD STEEL IN HYDROCHLORIC ACID
SOLUTION BY NATURALLY OCCURING ADDITIVES
Adeyemi O.O.; Oluwafemi S.O. And Adebogun A.A.
The corrosion rates and inhibition efficiencies have been determined in 5% hydrochloric acid solution in the presence and absence of plant extracts – pepper, tobacco leaves paw paw and orange peels. The inhibition of these extracts was presumed to be due primarily to presence of polar functional group with atoms of the elements of the family of group V and VI (N,O OR S) RESPECTIVELY. Pawpaw and Orange leaves’ extracts exhibited high inhibition efficiency and this increases with the period of immersion. Tobacco and pepper extracts were poor inhibition and in some cases promote corrosion instead of inhibiting it.
ESTIMATION OF CAFFEINE IN THREE VARIETIES OF KOLA NUT
CONSUMED IN KADUNA, NIGERIA
ABSTRACTCola nitida, Cola acuminata and Gircinia cola (bitter cola) were investigated for caffeine content. Among the varieties, cola acuminate recorded the highest percentage caffeine of 1.92% while Cola nitida (1.17%) and Gircinia cola (0.92%) followed in that order. These findings confirm that the three varieties of kola nut contain different level of caffeine with Cola acuminata having the highest caffeine level and preferred by the people of Kaduna. Therefore to exploit the full potential of kola nut, it is recommended that Cola acuminata be consumed. However, caution need be taken to avoid getting addicted.
APPLICATION OF TORSIONAL VIBBRATION ANALYSIS IN SYSTEMS MAINTENANCE
The stringent operational conditions that machinery undergo demands that an efficient and reliable vibration monitoring technique be promulgated for them. The reciprocating and rotating parts are of greatest concern. It is against this backdrop that a natural frequency method of torsional vibration
Analysis using the Holzer approach is proposed in this paper. Computer simulation was also adopted to carry out the analysis. In view of the assumptions made for the weights of the rotating parts, the damping coefficients of the bearing and spring constants, five modes of natural frequency were obtained before the operating speed to which the engine was de-rated to.
ASSESSMENT OF THE SUITABILITY OF EWEKORO CLAY AS
LINER FOR SANITARY LANDFILLS
The oil boom of the 1970s le to the growth of industries in Nigeria and consequently on increase in the number of cities from 3 to about 31. This resulted to population drift from the rural to the urban areas and the resultant effect is the growth of commercial activities. The increase in population in the urban areas was not marched with the necessary corresponding infrastructures like waste management facilities. Presently only one landfill exists in the country. Since the Federal Government intends establishing 14 additional landfill sites in the country t is necessary to find suitable material for the liner construction. Five clay soil samples from the West African Portland Cement quarry at Ewekoro in Ogun State of Nigeria were obtained and subjected to various soil tests. The results showed that 4 of the samples would be suitable for liner construction when subjected to the appropriate effort.
PRINCIPLES FOR ACCURATE REINFORCED CONCRETE
In order to eliminate various size/scale effects often observed in small size models of reinforced concrete, a new material similitude condition for the modeling of concrete has been proposed. This similitude condition relies on modeling concrete properties using the flexural compressive and tensile strengths of the concrete rather than the conventional approach of using the uni-axial strengths. This current approach attempts to capture the different conditions on materials in the prototype and the model. Using results of simple supported 1:10 scaled microconcrete beams failing in flexure, the factor (K;)Relating the flexural compressive strength of concrete in prototype to that of models was obtained as 0.9, for a scale of 1.10(i.e.~=
10) and this was extended to the tensile strength. Using this factor, microconcrete mixes were produced to satisfy the similitude conditions and
Thereafter used in tests on microconcrete beams failing in flexural and diagonal tension modes. Comparison with theoretical values revealed that flexural failure was predicted to an average of not more than 7% of theoretical predictions while diagonal tension failure was predicted to an average of 22% more than theoretical values. More work still need to be produce coarser mixes which will have lower tensile strength to meet tensile strength requirement.
PERFORMANCE CHARACTERISTICS OF DAIRY GOATS ON ALL ROUGHAGE RATIONS
Intake and digestibility of three different tropical forages were evaluated and compared in a feeding trial with dairy goats. Eighteen Red Sokoto goats (7.9+ 0.5kg initial BW) in a completely randomized design with 137d period consumed Tephrosia bracteolata (T1) (17.85% CP, 29.15% CF, 3.75% EE and 45.92% NFE) or received Lablab purpureus (T2) (10.51% CP, 40.17% CF, 1.75% NFE) ad libitum. Total DMI rose (p 0.05) with Tephrosia bracteolata feeding and Lablab purpureus than Andropogon gavanus which are significant (P 0.05) (420.20, 403.20 and 137.62g/d for T , T and T respectively). The mean live weight gain was 55.10g per day for T while the lowest gain was recorded for T (21.43g). The nutritive value index and ME intake were different among forages; greater for T T T Dry matter digestibility average 61.01 and was similar for all forages. Apparent digestibility coefficient of crude protein; crude fibre and ether extract increased (p 0.05) for T than the means of T and T . The estimated intake of digestible energy related to protein intake were 2.69 (T ), 1.32 (T ) and 0.19 (T ) compared with 0.70 M.cal. Recommended for goats of similar age (NRC, 1978).
DETERMINATION OF HEAVY METALS POPLLUTION AND DISTRIBUTION IN KADUNA SOIL
MOHAMMED F. DAHIRU
The total heavy metals content of the soil of Kaduna city and its environs were determined using atomic absorption spectrophotometry (AAS). The results showed that the soil was contaminated with Cd (7.70mg/kg), Co (484.15mg/kg), and Pb (170.66mg/kg) because their levels in the soil were above the maximum allowable limit, MAL, (3mg/kg, 50mg/kg, and 100mg/kg for Cd, Co and Pb respectively). The levels of the other metals, Zn (229.58mg/kg ; Ni (30.95mg/kg); and Cu (24.62mg/kg), were below their MAL values (300mg/kg, 50mg/kg and 100mg/kg for Zn, Ni and Cu respectively). The variation in metals in the sampled soils showed that Ni has the least variation (cv = 13.22) while copper showed the highest variation (Cv = 85.66). . The distribution of Pb was negatively skewed to the left (Sk = - 0.24) while those of the other metals were positively skewed to the right. Kurtosis values for Zn, Ni and Cd (K = 3.33, 2.98 and 2.93 respectively were unimodal while values for Co, Pb, and Cu tend towards bimodality.
SYNTHESES OF AZO COMPOUNDS BASED ON 2, 4, 6 – TRIAMINO-1,3,5-TRIAZINE AND ACYL DERIVATIVES WITH PHENOLIC – NAPHTHOLIC COMPOUNDS.
ISUWA K. ADAMU
Mono and Disazo dyes have been synthesized by the diazotization of 2,4,6- triamino – 1,3,5 – triazine and acyl derivatives followed by coupling with 1,3 – dihydroxy bezene, 1,3,5 – trihydroxybenzene, I – naphthol and 2 – naphthol. The monoazo dyes were synthesized by direct diazotization – coupling using the nitrosyl sulphuric acid reagent while their disazo counterparts were synthesized in the same manner and also by stepwise conversion of the mono azo dyes. The identity of products and their intermediates were investigated using chemical reaction test, UV – visible, FT – IR HNMR and CNMR spectroscopy. The disazo syntheses were found to involve a stepwise process with monoazo derivatives as stable intermediates. Also the disazo dye syntheses were accompanied by deamination in contrast to acylated derivatives, where deamination were not observed. This is attributed to the protective influence of acyl group to to substitution by inductive effect.
NON-METALLIC INCLUSIONS IN CALCIUM TREATED DEOXIDIZED STEELS.
Polished as-cast industrial samples of calcium treated high-strength, low-alloy (HSLA) steel were investigation in order to determine the non-metallic phases formed during production. Optical microscope and scanning electron microscope (SEM), can scan model equipped with an energy dispersive X-ray (EDX) analyzer (Link analyzer LZ-5) were used for preliminary classifications and analysis of inclusions. After converting their elemental compositions into their most thermodynamically stable oxides and finding the stoichiometric rations of the oxides, inclusions’ chemical formulae were determined using AI 0 - MgO, CaO - AI O and CaO - MgO slag systems. Three classes of inclusions were recognized: Small, spherical inclusions with diameter range of 1-12 pm, whose core approximates to CaOA1 O type of calcium aluminate – these were predominat; Large spherical inclusions measuring up to 150pm, with composition that corresponds to 12CaO7A1 O ; and irregular shaped inclusions(-15 pm) that contain pure A1 O and MnS. The composition, size and composition, and size shape and composition of the first, second and third class of inclusions respectively are detrimental to the properties of this steel grade.
APPLICATION OF THE TECHNIQUE OF OPTICAL TRANSMITTANCE TO MARK SENSING OR DETECTION
A technique for sensing of a dark mark on plain background suing light transmittance has been presented. A model of light transmittance through a plain and shaded paper media is developed. The model provides a theoretical approach using documented differential equations to describe light transmittance of a freely suspended paper layer. The resulting differential equations are solved analytically to obtain results and to determine the level of contrast between the plain paper and that of the shaded paper. From experiments the difference in response received from light intensities between the shaded and unshaded paper was significant and defines a contrast that distinguishes a mark from the surrounding (plain) paper. The differential transmittance is used to establish the presence or absence of a mark by setting a threshold for plain and shaded portions. Infrared light emitting diodes are used as light sources while photodiodes serve as light detectors.
CONTINOUS NUMERICAL METHOD IN ANALYSIS OF AXIS-SYMMETRIC EXTRUSION PFOBLEMS: NUMERICAL FORMULATION
C.O. IZELU – C.A. EBIOGWU – F.F. ORUMWENSE
An investigation of a new numerical approach to the solution of metal forming problems has been undertaken. The formulation and application of the method in the study of the mechanics of axis-symmetric extrusion are reported. The formulation involves finding a power series approximate solution of the governing Biharmonic Partial Differential Field Equation (BPDFE), posed in the plastic cylindrical co-ordinate region. In order to achieve this major purpose, the field equation is mathematically decomposed into as Ordinary Differential Equation (ODE) by means of the Centred Finite-divided Difference Equations (CFDE). When the Direchlet boundary conditions are applied, a coupled system of boundary value problem of the type found in the axis-symmetric extrusion process is produced. Solving this system, with the collocation method, yields a set of linear algebraic equations in coefficients of the assumed flow functions defined as polynomial functions. With these flow function coefficients determined, through solution of the resulting set of linear algebraic equations, the grid-line flow functions, and the formulated field equations may be evaluated to establish the distribution of the state and flow variables of extrusion. Expressions, which demonstrate how the extrusion and die pressure, and the process performance may be predicted from the field data, are also detailed.
THE IMPACT OF WIRELESS TELEPHONY ON PROVISION PLANNING IN THE
The paper presents a study of provisioning in the external line plant of NITEL, the Nigerian PSTN. Based on industry statistics or data, the analysis confirms the tremendous influence of maintenance inefficiency, lack of investment and most importantly the activities of competing operators with wireless technology on provisioning in the PSTN. The results indicate that dormancy is on the increase in the PSTN as the number of working lines continue to plummet while its competitor’s market shares continue to soar at an unprecedented pace. To arrest the increasing dormancy, economic and technology solutions have been discussed which should be of broad policy consideration.
THE SUITABILITY OF SC-TRANSDUCER TECHNIQUE FOR FLOW IMAGINE SYSTEM
This paper presents the fundamental feature4s of Switched Capacitor (SC) technique together with the capacitance flow imaging system. The capacitance transducer circuits and their modifications using switched-capacitor technique are discussed. Various approaches to solving the problems of noise, offset and drifts associated with switched-capacitor technique can be effectively applied to the realization of capacitance-based real-tomographic flow imaging systems.
EVALUATION OF SHELL PROPERTIES OF ANIMAL EGGS
ENOMFON J. AKPAN & IMO J. AKPAN
The physicochemical properties of eggshells belonging to difference classes of egg laying were evaluated. The physical properties considered were: colour, size, volume, thickness, mass and specific gravity. The colour of the eggs varied from white to brown. Some of the shells were smooth while the Quail eggshell was rough in texture. The width and length varied between 1.02 + 0.05 and 1.05 + 0.05cm in Lizard eggshell and 4.72 + 0.17 and 6.41 +0.05cm in Duck egg shell respectively. Volume, thickness, mass and specific gravity for Lizard egg shell which had the least values were 0.96 + 0.42cm , 0.18 + 0.05mm, 0.07 + 0.03g and 6.71x10 respectively white Duck egg shell with the highest values had 72.98 + 0.09cm , 039 + 0.06mm, 8.65 + 0.0.08g and 1.19x10 respectively. Eggshell highest values had 72.98 Masses showed a variation according to their size but eggshell thickness showed no relationship with the size or class of animal. The elemental compositions of the eggshells were also analyzed. Calcium was the highest in all the sample followed by sodium and magnesium. The Agric. breed had higher calcium contents than the local breeds. Calcium, magnesium and sodium were correlated with the physical properties like shell thickness, volume and mass. Manganese was generally low in all the eggshells analyzed. The concentration of calcium was much greater than that of phosphorus. Generally, the improved breed of fowls tends to have the desirable characters and the chemical constituent of their eggshells is higher than others. This may be due to the fact that the improved breed feed on synthetic feeds, which have been enriched with proteins, vitamins and minerals. From the results it is pertinent to say that eggshell should not be discarded for they have value.
PREVALENCE OF GUT HEKMINTHS INFESTATION IN GOATS SLAUGTHERED IN ZANGO ABATTOIR OF KADUNA METROPOLIS, KADUNA STATE
Incidence of end parasites of some goats slaughtered in Zango Abatoir of Kaduna from November, 1999 to October, 2000, was investigated. Out of the one hundred and fifty gut contents, each from a goat, 33 (22%) were infested with helminths. Adult helminths observed were: Taenia species (68.18%) and Strongyloides papillosus (31.18%), while the eggs of Ascaris species, Strongyloides species, and Nematodirus species were observed. Though the number of eggs observed in each gut sample is considered few, the consistency of some feacal samples was either normal, loose or diarrhoeic. Therefore, the helminth light infestation with loose or diarrhoeic stool observed in some goats was considered clinically significant enough to hamper the economic breeding of goats in Kaduna and its environs. Effective control of helminth parasites of goats is therefore recommended for this study area.
SOME STATISTICAL CHARACTERISTICS OF SOLUTIONS OF A CERTAIN CLASS OF DEGENERATE STOCHASTIC DIFFERENTAL EQUATIONS
In this paper, properties of stochastic integrals are used to obtain deterministic degenerate differential equations for the determination of first and order moments and correlation
Function of the solution of linear degenerate stochastic differential equations of the form.