Influence of die variables on cavity press forging loads

Slug, die and process parameters largely determine the load requirements when forging any given part. An earlier report (Balogun 1974) has indicated the effects of flash dimensions on deformation forces during cavity press forging of round mild steel slugs.

The current paper discusses the influences of three main die variables—die friction, extrusion ratio and flash land shape on press forging loads. The effects of die corner radii, draft angles and die complexity are also briefly mentioned to give a balanced outlook.     

An Investigation into the Lipid Classes of Skipjack Tuna (Katsuwonus pelamis)

The lipid classes of the muscle of Skipjack tuna (Katsuwonus pelamis) were investigated over a period of 10 months by thinlayer chromatography. Triglycerides, diglycerides, monoglycerides and phospholipids content varied between 48.36 ± 1.22% and 62.49 ± 3.40%; 20.04 ± 5.59 and 28.53 ± 4.50; 0.98 ± 0.20% and 4.84 ± 2.48% and 4.31 ± 0.96% and 9.26 ± 0.52%, respectively. Both triglycerides and diglycerides formed the major fractions (between 68 and 91%) of Skipjack muscle lipid. There was a good concentration of phospholipids. Free fatty acid levels were fairly low and varied between 0.62 ± 0.10% and 3.94 ± 0.31%. No levels of hydrocarbons were detected in lipid samples from May to September but fairly high levels of (14.97 ± 2.89% and 12.74 ± 2.68, respectively) were detected in November and January samples.     

Some spectral signatures of Grain Amaranthus (A mar ant has cruentus,L)

Abstract

Ground-based solarimetric measurements on Grain Amaranthus (A. cruentus, L) were made at Akure, Nigeria Latitude 7°N; Longitude 5° E), over a growing season. The solarimeters were fitted with gelatin optical filters (Kodak No. 88A) for measurement in the infrared portion of the solar spectrum. Profile measurements within the canopy were also made at full canopy cover. Simulta neous measurements of the leaf area index (LAI), dry matter production (DM), and photosynthate partitioning (PP) were also made. Results show an increase of infrared reflectance from 0.11 to 0.35 at full canopy cover after which it starts a downward trend. The relations between normalized difference vegetation index (NDVI) and LAI and DM were cubic. It was also observed that the normalised difference was also sensitive to the phenological stage of the crop in that it shows a lower rate of increase when the partitioning of the photosynthates began. Transmitted infrared (IR) radiation within the canopy was observed to increase with depth.     

Studies on size distribution of skipjack tuna (Katsuwonus pelamis): effect on chemical composition and implications for its utilization

Size and composition of skipjack tuna in Nigeria's Exclusive Economic Zone were investigated between May 1982 and January 1983. Monthly average length ± standard deviation varied between 41.65 ± 2.64 cm in January 1983 and 46.60 ± 3.02 cm in September 1982. Corresponding average weight varied between 1.34 ± 0.18 and 1.90 ± 0.37 kg. After logarithmic transformation of the variables (length and weight), a correlation coefficient of 0.901 was obtained. Frequency distribution of length classes enabled three size groups (small, medium and large) to be distinguished. Moisture, protein and ash content of fillets were not significantly affected by the size of the fish, but lipid content increased significantly ( P < 0.05) with size. Widest variations were observed in salt content, which decreased significantly ( P < 0.05) with increase in size. All chemical components were significantly affected ( P < 0.05) by seasonal variation. The implications for the fishery and utilization of this resource are discussed.