Agricultural and Food Engineering

Definite environmental problems including climate change are visible since the inception of
oil exploration in the Niger Delta region of Nigeria in the last 50 years. Incessant oil spill has
damaged the ecosystem destroying plants on land and in water. The rich mangrove of the coast of
the gulf of guinea is seriously depleted. Much of the land is left bare without plants thus leading to
excess of carbon in the atmosphere. Gas flaring is not reduced till today. Trucks, many which are ill
maintained and coming for oil business from all the land sends much emission into the air. The
deforestation due to oil spill, gas flaring and emissions from vehicles, all contribute greatly to excess
carbon. This causes overheating of the atmosphere and rise in temperature. Thus, there is excessive
evaporation from the nearby ocean and water bodies and ultimately leading to very heavy rainfall
and flooding. It is observed that the weather conditions including rainfall pattern has changed greatly
in the last 20 years. Too much rainfall has caused serious soil erosion, leaching and poor soil fertility
leading to poor agricultural productivity. These problems can be reduced by enforcing laws to control
oil spill and gas flaring. Emissions can also be controlled by blending biodiesel with diesel fuel.
Fortunately, a very effective biodiesel, the Dura palm oil biodiesel obtained from the Dura Oil palm
has been found to cut down emissions of fuel pollutants such as CO by up to 60%

Some famous local spices were selected to determine their potentials in terms of their aroma and utilization. They included
Tea Bush (Ocimum basilicum), Guinea Black Pepper (Piper guineense), African Pepper (Xylopia aethiopica), Aiden Tree
(Tetrapleura tetraptera) and the African Meg Nut or Onion Tree (Blighia unijugata). Essential oils were extracted from the samples and used for aroma absorption test in a uv-visible spectrometer V2.03. The intensity of aroma was indicated at some peak values of absorption at particular wavelengths. The compounds responsible for the aroma at this peak values were identified by matching their wavelengths with those of known compounds at similar wavelengths of absorption. Thus, a compound such as Quinoline that has hot strong aroma and little bleaching effect was proved to be present in Guinea black pepper at the wavelength of 313.0 nm. Benzene with hot strong aroma and flammable effect was also indicated in this spice at the wavelength of 253.0 nm. Proximate analysis
carried out showed that these spices have high nutritive values. Some of them such as Guinea black pepper, African Nutmeg and Ethiopian (African) pepper had high ether extract of 20.01, 25.97 and 31.25 respectively, and could be regarded as oil seeds, they contain much of essential oils.

An electrically operated cassava pelleting machine was designed, fabricated and tested. The Cassava pelleting machine was developed with efficiency and low cost in mind. It also aimed at eliminating the problem of transporting Cassava product and also for the production of pellets for animal feeds. The single screw shaft was chosen based on the ease of fabrication, availability of the components parts and simplicity of operation. The machine has an efficiency of 98.66% and the machine capacity is about 80kg.

The delineation of watersheds can be carried out manually using topographic maps but these maps are mostly outdated, scarce and incomplete for most parts of Nigeria and may be of different scales for large watersheds that require several sheets of the map. Watershed boundaries need to be delineated accurately because the areas and perimeters of watersheds are used in many hydrological analyses. This study is aimed at delineating the River Dep watershed and stream network using 90m SRTM Digital Elevation Model and Geographic Information Systems technique and comparing the shape and pattern with the one previously delineated manually using topographic maps and areal photographs. The 90 m SRTM Digital Elevation Model used for the study was obtained from the Global Land Facility Cover site and processed in ERDAS Imagine 9.2 before exporting to ILWIS 3.7.1 ACADEMIC. The watershed area obtained from the GIS delineation processes was 10640 km 2 while it was 9600 km 2 from the report of the one delineated by manual methods in 1980. The same 1980 manually delineated watershed when scanned, imported, georeferenced and digitised in ILWIS 3.7.1 gave a watershed area of 10244 km 2. The differences in the watershed area could be due to the effect of input data or errors from the estimation using Original Research Article Daffi and Ahuchaogu; AJEE, 4(4): 1-8, 2017; Article no.AJEE.35972 2 traditional delineation. The study showed similarity in shape and pattern for both the watersheds and stream networks delineated using the two methods. The study shows the capability of the ILWIS DEM hydro-processing tools used for watershed and stream network delineation using the 90m SRTM Digital Elevation Model and it is recommended that the both can be used with a reasonable level of accuracy.