Estimation of contaminant transport parameters for a tropical sand in a sand tank model

This research describes the goals, design and implementation of a quasi natural gradient, laboratory scale, sand tank (aquifer) model experiment. The model was used to study the transport of an inorganic tracer (Chloride) in groundwater, within a tropical aquifer (porous medium) material. Three-dimensional sand tank (1.8 m × 0.3 m × 0.8 m) experiments were conducted to investigate contaminant transport and natural attenuation within the sand tank. In all, 360 samples were collected during 24 sampling sessions, for the three days of the tracer experiments in the Sand Tank. The Owena sand is a poorly graded sand with 88.1 % sand and 11.9 % gravel. Geotechnical properties including; coefficient of uniformity Cu = 2.53, coefficient of gradation Cz = 0.181, hydraulic conductivity K = 5.76 x 10-4 m/s, bulk density ρ = 1.9 Mg/m3, effective porosity ne = 0.215 and median grain diameter D50 = 0.55 mm, were determined. Other relevant hydraulic and solute transport parameters, such as dispersion coefficients and dispersivities were also established for the tropical soil

Implikasi Putusan Mahkamah Konstitusi Nomor 92/puu­x/2012 Terhadap Proses Pembentukan Undang­undang Di Indonesia

Popular sovereignty of Indonesia is implemented through representation system. Actually, Indonesia implements tricameral system because it consists of MPR, DPR, and DPD. But in fact, it is typically as unicameral system because DPD's function is weaker than DPR's, especially in legislation function, such as regulated by Law Number 12 of 2011 on Establishment of Laws and Regulations which was sued to Constitusional Court. After the Constitusional Court Desicion Number 92/PUU-X/2012, there are implications on the law making process, namely DPD can promote their proposal and it's recognized as DPD's proposal. Besides, DPD has authority to discuss their proposal until the second level before approval process. This paper will present the law making process before Constitusional Court Desicion a quo and its implication towards the law making process.IntisariKedaulatan rakyat di Indonesia dilaksanakan melalui sistem perwakilan. Secara struktural, Indonesia menganut sistem perwakilan trikameral karena terdiri dari MPR, DPR, dan DPD, walaupun secara praksis tampaknya unikameral. Hal ini karena fungsi DPD lebih lemah dibandingkan DPR, terkhusus fungsi legislasi. Sebagaimana dalam Undang-Undang Nomor 12 Tahun 2011 tentang Pembentukan Peraturan Perundang­Undangan, sehingga kemudian diuji materiilkan ke MK. Pasca Putusan MK bernomor 92/ PUU­X/2012, terdapat implikasi pada proses pembentukan undang­undang, diantaranya terkait usul DPD yang diakui sebagai usul lembaga serta keikutsertaannya dalam pembahasan tingkat I dan II sampai sebelum persetujuan. Tulisan ini membahas mengenai proses pembentukan undang-undang sebelum putusan MK serta implikasinya terhadap proses pembentukan peraturan Perundang-undangan

Slug Tests for Determination of Hydraulic Conductivity of Contaminated Wells

This paper reviews three models for analyzing slug test data to determine hydraulic conductivity of hydrocarbon contaminated wells in the study area. 50 grams/litre potassium permanganate (KMnO4) was used as permeating fluid for the remediation of the site. Data of the slug-in test from five (5) observation wells varying in diameter from 0.82-1.93m in the study area in Baruwa, Lagos Nigeria were analyzed with three models used in the study, namely; Hvorslev, Ferris –Knowles and Earth Manual models. Analysis of the data showed that all three analytical methods produced similar range of magnitude of the order of 10-4cm/sec values of hydraulic conductivity

MEASUREMENT AND ESTIMATION OF SOIL WATER CHARACTERISTIC CURVE FOR FOUR UNSATURATED TROPICAL SOILS

Infrastructures are mostly built on unsaturated soil in the tropical region such as Nigeria, yet soil investigations and designs are based on saturated soil mechanics owing to difficulties associated with soil suction measurements using direct methods such as pressure plate extractor, triaxial testing equipment for testing unsaturated soil, etc. Soil water characteristic curve is an important parameter for estimating unsaturated soil property function. This research considered an indirect method (filter paper) of laboratory soil suction measurement (which is relatively simple, fast and inexpensive) and predictive correlation equations for estimating soil water characteristic curve from index properties of soil for four unsaturated tropical soils of Nigeria, three predictive correlation equations were used in this research namely; Navid et al model (2012), Zapata et al model (2000) and Witczak model (2006), the soil water characteristic curve constant parameters computed from these models were fitted through either Van Genuchten model (1980) or Fredlund & Xing model (1994). Results of air entry values of soils from experimental work and predictive correlation equations were in close range which indicated that in spite of the difficulties experienced in performing laboratory suction test, the predictive correlation equations such as the ones used in this research were found to be proper for estimating soil water characteristic curve

Far-infrared induced current in a ballistic channel -- potential barrier structure

We consider electron transport in a ballistic multi-mode channel structure in the presence of a transversely polarized far-infrared (FIR) field. The channel structure consists of a long resonance region connected to an adiabatic widening with a potential barrier at the end. At frequencies that match the mode energy separation in the resonance region we find distinct peaks in the photocurrent, caused by Rabi oscillations in the mode population. For an experimental situation in which the width of the channel is tunable via gates, we propose a method for reconstructing the spectrum of propagating modes, without having to use a tunable FIR source. With this method the change in the spectrum as the gate voltage is varied can be monitored.Comment: Submitted to Phys. Rev.

AN ASSESSMENT OF THE STATUS OF SMALL RICE THRESHERS IN NIGERIA

An assessment of existing rice thresher designs and products available within Nigeria and neighbour-         ing countries was carried out. The impetus for the study is the concern that low and poor quality of         local rice in Nigeria may be due, in important measure, to lack of appropriate and affordable small        threshers. On this basis, a reconnaissance work in Five Local Government Areas in Ogun State,    Erin        – Ijesha in Osun State, Igbimo in Ekiti State; Abakaliki in Ebonyi State, Makurdi in Benue State as well        as   Kura  -  Kano   and   Tundun   Wada   areas   of   Kano   State   was   carried   out.   Based   on   the   farmers’        evaluation   and   assessment   of   existing   rice   threshers   available   in   Nigeria,   the   study   recommended        three prototype small threshers that are pedal and petrol engine driven. The pedal operated thresher        was recommended for those with farm hectarage of less than 2. For threshing freshly harvested rice at        very   high   moisture   content,   the  IITA/WARDA   small   plot   spike-tooth   thresher   which   has   a  threshing        capacity of about 100kg/h was found to be appropriate for the small – scale farmers provided some         little modifications in the area of capacity and mobility were carried out while the multi-crop thresher of        the Institute of Agricultural Research and Training (IAR&T) Ibadan with a capacity of about 250kg/h        was recommended for those with farm hectarage of more than 5ha.&nbsp

Effect of frozen period on the chemical, microbiological and sensory quality of frozen tilapia fish (Sarotherodun galiaenus)

The study was designed to investigate the effect of duration of frozen storage on the chemical, microbiological and sensory profile of Tilapia fish (Sarotherodun galiaenus) collected from a research pond of the Agricultural Development Project, Akure, Nigeria and were subjected to sixty days of frozen storage and analyzed at intervals of ten days. Protein content (%) ranges from 43.70 &#177 1.17-60.65 &#177 2.40. Protein decreases with increasing duration of frozen storage with the fresh samples (not frozen) having the highest protein content (60.65 ± 2.40) while the least (43.70 &#1771.17) was recorded for fish samples that were frozen for sixty days. Similar results were obtained for the fat content (%) where the highest fat content (9.72 &#177 0.25) was recorded for the fresh samples and the least value was recorded for those stored for sixty days. Ash content (%) and moisture content (%) do not show any significant change during storage. Mineral composition (Fe, Ca, Mg, P and Zn in mg/100g) and iodine content (µg/100g) of the samples showed a slight change with respect to duration of storage. pH values ranges between 5.20-6.90 while the total coliform count range was between 3.0 x103-7.5 x 106 with increasing values, as the duration of torage increases. Sensory evaluation of the fish samples on storage revealed that quality of the fish samples with respect to taste decreases with increasing duration of storage with the best quality (texture, odor and color) when freshly prepared; and that better quality during storage is obtainable during the first ten days of storage. These, by implication simply mean that fish should be stored for a short period of time to retain the taste, and provide both the protein and fat at optimal level. Key words: Frozen period, chemical, microbiological, sensory quality, tilapia fish.African Journal of Biotechnology Vol. 4 (8), pp. 852-85

Inflation and Some Unpleasant Fiscal – Monetary Issues in Nigeria: A Reassessment of the Role of Government in the Management of an Economy.

Fiscal and monetary issues are linked through money growth in the form of Seigniorage, which provides revenue to the fiscal authority in the management of an inflationary – prone economy. The relationship between these macroeconomic aggregates are well documented in the literature. This study undertakes an empirical assessment of some (un)pleasant fiscal and monetary issues in Nigeria with the main objective of identifying the role of government in the stabilization of an economy. Using data over 1970 – 2013 periods, this study adopts a modeling approach that incorporate both structural and co-integration analysis and found significant relationships between the macroeconomic variables and inflation in Nigeria. It concludes with some far reaching recommendations including minimization of deficit, adoption of robust fiscal adjustment mechanism that could increase revenue and discouraging deficit financing by the Central Bank. Key words:Fiscal deficit, inflation, money supply co-integration

MODELING THE PERFORMANCE OF A BAOBAB SEED DECORTICATOR USING RESPONSE SURFACE METHODOLOGY

Decortication of baobab seed manually after soaking or roasting is time consuming, labour-intensive and uneconomical. The demand for baobab kernel as a source of protein is increasing for use as supplement for animal protein ration, for edible oil consumption and for other industrial uses. To ameliorate this problem, a baobab seed decorticator has been developed. This study therefore focused on the effects of process parameters; moisture content of seed, speed of decorticator and concave-shaft clearance on percentage clean kernel (Pck), percentage broken kernel (Pbk), percentage whole seed (Pws) and decorticating efficiency (DE), using Response Surface Methodology (RSM). In designing the experiments, Box-Behnken Design (BBD) was selected. Analysis of Variance (ANOVA) was carried out to evaluate and select the appropriate dependent (Pck Pbk, Pws and DE) and independent variables using both the F and P-values calculated at 95% confidence level (a=0.05). Mathematical models relating the process parameters to the responses were developed. The developed models were validated by comparing the predicted and actual experimental values. The selected quadratic models were adequate for predicting the performance of the developed decorticator. It was observed that a decrease in percentage clean kernel recovery would result if concave-shaft clearance and moisture content were increased. Likewise, the concave-shaft clearance had the highest positive effect while moisture content had the highest negative effect on percentage of broken kernel. All the three factors (process parameters) had positive effects on decorticating efficiency

Development and Evaluation of a Combined Castor Seed Roaster-Oil Expeller

This study evaluated optimal process parameters for mechanical oil expression from castor seeds after designing a castor seed roaster-expeller. The effect of input variables (Moisture Content at 6, 7, 8, 9 and 10% db; Roasting Temperature at 80, 90, 100,110 and 120oC and Applied Pressure at 15, 20, 25, 30 and 35 MPa) on the oil yield, expression efficiency, expression loss and energy used were determined using Central Composite Design in Response Surface Methodology for the optimization and modelling. Analysis of Variance was employed to determine the level of significance (P≤ 0.05). The optimum expression efficiency, expression loss and minimum energy used were 72.86%, 0.63% and 584.19 Watts obtained at experimental conditions of 15.00 MPa applied pressure, 6% moisture content and 85.52°C heating temperature respectively. The R2 values of the developed models ranged from 0.813 to 0.982 at 95% confidence level. The developed combined castor seed roaster-oil expeller was found to be efficient and developed models showed adequate prediction with good relationships between dependent and independent variables. Keywords: castor seed, oil extraction, modeling, optimization DOI: 10.7176/ISDE/11-1-07 Publication date: January 31st 2020