Insight into Agricultural Mechanization in Cameroon: Case of Farm Operators, Users of Agricultural Equipment and Machines
Abstract— Cameroon has an economy strongly dominated by the agricultural sector and despite this domination as well as the fact that this sector is backed by several policy documents and statements, investments in the sector is still grossly underdeveloped. Many farm operators in the different agro ecological environment still rely to an overwhelming extend on the use animate power to achieve their agricultural production goals. This power source and the tools used have implicit limitation in terms of energy and operational output. Cameroon government persistently carry out some initiative to inverse the tendency such as the providing modern agricultural equipment and machinery to farm operators, training complex farm machinery users. However, these solutions are not part of a common though and so far have produced mixed results without a significant improvement on the field. This paper permits to appreciate the challenges faced by users of farm technology in agricultural mechanization via four main crops of significant importance to Cameroon: Maize, Cassava, Sorghum and Cocoa.
Among others, it was observed that 75% of farmers involved in cultivation of sorghum, maize, cassava have land surfaces less than 2%. These small farm sizes are a serious handicap to the effective mechanization due to sparse and scattered cultivated lands. Also, only 13% (112) of farm operators have access to credit from micro finance institutions. This low access to credit contributes to the reluctance of farm operators to invest in agricultural machinery acquisition with only 3% owing a land with a land title.
Keywords— Adoption, Challenges, Farm operators, Insight, Mechanization.
Abstract— The present article describes the effect of the pressure on the operability of the plate exchanger of the SWEEP IC 5 x 20 type as well as the results of the numerical analysis of the stresses at three different loads. The exchanger was tested at the testing pressure defined by the manufacturer (2 MPa). Maximum stresses were observed at the places of soldered joints on individual exchanger plates and the stress was highly above the carrying capacity of the solder joint. With an increasing distance from the place where the boards were connected, stress exhibited a sharp increase. The testing was also focused on the stresses on the surface area (shroud) of the exchanger at the permissible operating pressure of 1.6 MPa defined by the manufacturer. An important observation was the stress identified at the measured real operating pressure of 0.7 MPa ̶ destruction of the exchanger used by the operator.
Keywords— plate heat exchangers, numerical analysis of stress.
Immobilization of commercial lipase onto different supports: characterization and application in esterification reaction
Abstract— The current preference of costumers for natural and healthy products is increasing the employment of biotechnological processes that use enzymes, and the synthesis of esters is an example of this change. However, enzymes are high-cost product, which stimulates research in finding solutions that make them more economically attractive, like immobilization. This work aimed to use different protocols for immobilizing lipase and its application in ester synthesis. The results showed that Pseudomonas fluorences lipase (AKL) was the most efficient for immobilization among other studied lipases (Pseudomonas fluorences lipase (AKL), Pseudomonas cepacia lipase (PSL), Hog Pancreas lipase (PHL), Pancreas Porcinas lipase (PPL), and Mucor Javanicus lipase (MJL)), with hydrolytic activity of 3323.6 U/g. Both immobilization methods (physical adsorption and entrapment) showed promising results towards hydrolytic activity. The best immobilization by adsorption was obtained using AKL onto PHB (polyhydroxybutyrate), with 698.61 U/g of hydrolytic activity. For entrapment, AKL also presented the best result, with 247.30 U/g of hydrolytic activity. For the synthesis of ester, after a 60 h-reaction using the immobilized derivatives by physical adsorption, the esterification yield was 74.26 %. In terms of hydrolytic activity, the employed protocols were very promising and encourage the continuity of this study towards the optimization of processes using industrial lipases.
Keywords— Adsorption, Entrapment, Lipase, Ester, Hydrolysis.
Abstract — The mechanism and kinetics are developed for the initiated non branched-chain formation of ethanediol in methanol–formaldehyde solutions at formaldehyde concentrations of 0.1–3.1 mol dm–3 and temperatures of 373–473 K. The experimental concentrations of the free insolated form of formaldehyde are given at the different temperatures and total concentrations of formaldehyde in methanol. The experimental dependence of the radiation-chemical yields of ethanediol on formaldehyde concentration in γ-radiolysis of methanol–formaldehyde solutions at 373–473 K is shown. At a formaldehyde concentration of 1.4 mol dm–3 and T = 473 K, the radiation-chemical yield of ethanediol is 139 molecules per 100 eV. The effective activation energy of ethanediol formation is 25 ± 3 kJ mol–1. The quasi-steady-state treatment of the reaction network suggested here led to a rate equation accounting for the non monotonic dependence of the ethanediol formation rate on the concentration of the free (unsolvated) form of dissolved formaldehyde. It is demonstrated that the peak in this dependence is due to the competition between methanol and CH2=O for reacting with the adduct radical HOCH2CH2O•.
Keywords — Methanol, Formaldehyde, Formation, Ethanediol, Radiation-Chemical Yield, Rate Equation.
Abstract— Agents in E-RTA possess the organizational knowledge that only specifies the list of agents that currently belong to its organization. For joint problem solving agents need to identify team members and do not maintain explicit models of other agents' capabilities. Task allocation protocol’s aim is to formulate an automated method for agents to find a 'suitable' agent who is 'available' to perform collaborative task.
It is necessary to ensure that the activities of agents always remain coordinated and Joint intentions guide problem-solving activity and play a key role in guaranteeing coordination among agents within an organization in complex and dynamic environments. We also assume that agents possess any time solutions to goals. This is done so that an executing goal can be terminated before its normal completion to avoid priority conflicts of requests.
This paper described the task allocation & protocols used for our proposed framework E-RTA. This complete paper described introduction in section 1, task allocation in section 2 in detail. Section 3 deals with temporal conflicts resolution method among intentions. Section 4 describes the results of our experiment and finally conclusion in section 5.
Keywords— E-RTA, Joint Problem, Task allocation protocol, problem-solving activity.