PKFokam Journal of Science and Technology

The KFokam Journal Of Applied Science & Technology

Serve as information carrier for industrialists, companies or business actors who are willing to transfer the results of applied research out of laboratories into practical application

journal

Current: Vol.3 , May 2023

Review, Design and artisanal fabrication of anaerobic biodigester for biodegradable waste

Fabien Kenmogne1*, André Abanda2, Madouma Madouma Arnold 3, Willy Arnold Donda1,4, Ulrich Nota Yemetio 1,4 ,Emmanuel Yamb1

1Department of Civil Engineering, Advanced Teacher Training College of the Technical Education, University of Douala, Cameroon.

2Department of Civil Engineering, National Advanced Polytechnical School of Douala, University of Douala, Cameroon.

3Ecole normale supérieure de l’enseignement technique(ENSET) de Libreville, Université Omar Bongo, Gabon

4Laboratory of mechanics, Advanced Teacher Training College of the Technical Education, University of Douala, Cameroon

*Corresponding Author: email: kenfabien@yahoo.fr

 

The purpose of this research work is to design and fabricate a bio-digester with HDPE (high density polyethylene) geomembrane material which will be effective in recycling biodegradable waste and unisonly produces biogas and organic liquid fertilizer. At the first time, a tubular trapezoidal bio-digester was designed using computer-aided design (CAD). After that, a 300 litters prototype bio-digester was manufactured with a tarpaulin. After running air and water tightness of the system, we fed it with quantified biodegradable waste and observed for a period of 60 days. Several tests were then conducted on the bio-digester to ensure that the system could support the load to which it would be subjected under normal functioning condition. These tests included shear test, peel test, and air tightness of the system. Results obtained from the prototype and the HDPE geomembrane bio-digester shows that, this design allows the recycling of biodegradable waste from any facility. The biogas obtained was proven to be rich in methane (52-73%) content and the organic liquid fertilizer was also rich in N-P-K fulfilling the basic requirement for plant healthy growth. Economically, the HDPE geomembrane bio-digester could produce 1,250L of biogas daily at an approximate pressure 1.8 bars which can be approximated to 5 hours minimum burning with a burner of 200L/h (ie a gas burner of about 1 kW of power).

Keywords: Geomembrane, Biodegradable waste, Methane, biogas, fertilizer, Hydraulic retention time, biodigester.

Optimization of adsorption parameters of carotenoids from palm oil on montmorillonite clays for using in mask face

Orléans Ngomo

Department of Organic Chemistry, Faculty of Sciences, University of Yaoundé I PO Box. 812 Yaounde, Cameroon

Corresponding author: orleansn@yahoo.fr

 

The adsorption of carotenoids from palm oil on montmorillonite clays from Maroua in the Far North Region of Cameroon was carried out by optimisation of some parameters. The physicochemical characterization of carotenoids was performed by determination of absorbance using the UV-Visible Spectrophotometer and making High Performance Liquid Chromatography. The amount of carotenoids adsorbed was determined by making the difference in optical density before and after adsorption. In order to determine the magnitude of adsorption from a reduced number of experiments, the centered composite design was adopted through three factors which can influence the adsorption: time (15 – 45 min), temperature (25 – 65 °C) and the concentration (20  – 50 mg.L-1). Of these three independent variables, the concentration was the factor which had a greater influence on the response surface and the iso-response of the adsorption (about 84%), while temperature influenced the least (i.e. around 0.77%). The optimum amount of carotenoids adsorbed was 1.76 mg.g-1 for the contact time values ​​of 30 minutes and the initial concentration of 35 mg.L-1. The coefficient of determination, the absolute analysis of the mean deviation, the bias factor and the accuracy factors made it possible to validate the model.

 Keywords: adsorption, carotenoids, clays, optimization.

Vol.2 , Issue 1, Sept 2020

Full original manuscript

From plant to drug: Galenic preformulation based on Phyllanthus amarus

KAMGAING Théophile1,2, TCHA FOKOU Gwladys2, NNANGA NGA Emmanuel3, FOKUNANG Charles3

1Department of Chemistry, Faculty of Sciences, University of Dschang2CRESA Forêt-Bois, Faculty of Agronomy and Agricultural Sciences, University of Dschang 3Faculty of Medicine and Biomedical Sciences, University of Yaoundé 1 

Abstract

Conventional treatments for liver damage exist but not accessible to low middle-income countries (LMIC) populations. Due to this limitation, traditional healers use plants that they consider effective for the treatment of local diseases. One of the most popular herbal plants is Phyllanthus amarus used as a decoction, but without insurance of safety, efficacy and quality. The objective of this work was to develop a drug based on this plant according to the requirements of the international pharmacopoeia. Thus, tests of hepatoprotective activity, acute toxicity and galenic preformulation were carried out. Phytochemical screening showed the presence of polyphenols, flavonoids, cardiac glycosides, tannins and coumarins. The aqueous extract of the plant was administered to rats at different doses (100, 200 and 400) mg/kg/PC for seven days and paracetamol was administered on the fifth day at a dose of 2000 mg/kg/PC to induce disease; sylimarine was used as the reference standard drug. The results showed good protection of the liver at the dose of 400 mg/kg/PC. As for acute toxicity, the dose of 2000 mg/kg/PC of extract showed no signs of harm. An Improved Traditional Medicine (ITM) was preformulated as a capsule from the aqueous extract of this plant. The pharmaceutics controls carried out on these capsules made it possible to conclude that this Improved Traditional Medicine conformed to the production standards of the International Pharmacopoeia.
Keywords: Phyllanthus amarus, metabolites, hepatoprotection, preformulation, quality control
Headlines: Introduction, Experimental section, Results, Discussion, Conclusions, Know-How Transfer

Research Article

Full original manuscript

Probability Distribution Modelling of Microwave Radio Refractivity over Selected Locations in Nigeria

Dada Joseph Babatunde.1, 2*, Adediji Adekunle Titus.1, Ogunjo Samuel Toluwalope.1, Ashidi Ayodeji Gabriel.1 , and Akinremi Moses Oluwadamilare1
1Department of Physics, Federal University of Technology, Akure. P.M.B 704, Ondo State, Nigeria
2Department of Physical and Chemical Sciences, Elizade University Ilara-Mokin. P.M.B 002, Ondo State, Nigeria

Abstract

In this study, distribution models were used to model radio refractivity of some stations across the various climatic zones of Nigeria. Eleven years (January 2004 to December 2014) of Meteorological Data from ERA INTERIM Re-analysis data were used to calculate radio refractivity of each location. It was observed that normal distribution among the probability distribution functions, predicts the peak of the distribution curve and gives the best fit for radio refractivity in all the locations. Weibull distribution strength is built from a small sample sizes. The distribution of the mean value of refractivity in the coastal areas was observed to be weak.

Keywords: climatic zone, distribution models, era interim, meteorological data, normal distribution, radio refractivity.

Headlines: Introduction, Results and Discussion, Conclusions, Experimental Section, Know-How Transfer

Vol.1: Inaugural Issue ; June 2019

Research Article

Full original manuscript

Effect of Single Superphosphate and Arbuscular Mycorrhizal Fungi on Growth and Bambara groundnut (Vigna subterranea (L.) Verdc.) Yield

TEMEGNE NONO Carine1*, GOUERTOUMBO Willy Franz1, NKOU FOH Dalida1, WAKEM Germaine-Alice1, NTSOMBOH-NTSEFONG Godswill1,3, Atabong Paul AGENDIA1, TAFFOUO Victor Desiré2, YOUMBI Emmanuel1

1Department of Plant Biology, Faculty of Science, University of Yaounde I, P. O. Box 812 Yaounde, Cameroon.
2Department of Plant Biology, Faculty of Science, University of Douala, P. O. Box 24157 Douala, Cameroon.
3Department of Valorization and Innovation, Institute of Agricultural Research for Development, P. O. Box 2123 Yaounde, Cameroon.

Abstract

The aim of this study was to reduce food insecurity by improving the yield of Bambara groundnut with phosphorus fertilizer. The experiment was carried out in the field at the University of Yaounde I. The experimental design was a split plot with three factors; landraces (V1 and V2), single superphosphate doses (0, 50, 100, 150 and 200 kg P2O5.ha-1) and AMF inoculum (M0: -AMF and M1: +AMF). P2O5 doses and AMF (composites Gigaspora margaritaAcaulospora tuberculata and Glomus intraradices) significantly boosted growth (number of branches, shoot height) and yield of Bambara groundnut. The dose 150 kg P2O5.ha-1 significantly increased the yield by 100% compared to the control (0 kg P2O5.ha-1+M0) in V1. AMFs significantly increased the yield by 87.5% compared to the control in V2. P2O5 and AMF independently improved the grain yield. However, low doses of P2O5 (100 kg.ha-1) may be associated with AMF to maximize grain yield of Bambara groundnut.

Key words: Arbuscular mycorrhizal fungi, Bambara bean, fertilizers, phosphate starvation, phosphorus.

Headlines: Introduction, Results and Discussion, Conclusions, Experimental Section, Know-How Transfer

Research Article

Full original manuscript

Secondary metabolites from Desmodium ramosissimum G. Don (Fabaceae) and their radical scavenging properties

Raymonde A. Dzatie Djoumbissie1, Didy H. Sonfack Fozeng1, Yves M. Mba Nguekeu1, Pierre Tane1, Hiroyuki Morita2, Maurice D. Awouafack1*
1Natural Products Chemistry Research Unit, Department of Chemistry, Faculty of Science, University of Dschang, P.O. Box 67, Dschang, Cameroon
2Institute of Natural Medicine, University of Toyama, 2630-Sugitani, Toyama 930-0194, Japan

Abstract

This work was designed to carry out the phytochemical study and the radical scavenging screening of the MeOH extract from the whole plant of Desmodium ramosissimum used in traditional medicine for the treatment of malaria, fever, diarrhea, lung disorders and venereal diseases. The crude extract was subjected to silica gel open column chromatography (CC) follow by repeated silica gel CC purification and / or Sephadex LH-20 to afford nine compounds, D-pinitol (1), mixture of β-sitosterol (2) and stigmasterol (3), β-sitosterol-3-O-β-D-glucopyranoside (4), glyceryl-1-tetracosanoate (5), lutein (6), kaempferol (7), catechin (8) and vitexin (9). The structures of these compounds were identified after analysis of their NMR and MS data and comparison with the literature. The crude extract, fractions III, IV and V displayed constituents possessing radical scavenging activities using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) bioautography while vitexin (9), and catechin (8) showed activity among the isolated compounds.

Key words: Desmodium ramosissimum; constituents; Radical scavenging, Vitexin; Kaempferol.

Research Article

Full original manuscript

A decentralized strong authentication access system based on rfid, face recognition and raspberry pi

SWI Innocent CHE*, LIENOU TCHAWE Jean-Pierre †
*The University of Dchang, Faculty of Sciences, department of Mathematics and Computer Sciences                              
†The University of Bamenda

Abstract

Access to most secure areas is controlled with use of mechanical lock and key. The objective of this paper is to design a secure door access system using face recognition, raspberry pi and RFID, with capability of data collection and treatment. In this paper, we present three sub-systems that is a system to read, write and protect data on RFID card using raspberry pi and RC522, (The face recognition module has been successfully tested on students attendance) then a decentralized secure access system using the above components with the single addition of a stepper motor which functions as an actuator, finally a web platform to remotely access user data log. Radiofrequency identification (RFID) is a technology that uses radio waves to transfer data from an electronic tag, called RFID tag or label, attached to an object, through a reader for the purpose of identifying and tracking the object. In our case, it is used to identify a person. When the holder of the tag places the card near the reader, the information is read and cross-referenced in the database for authenticity. If the information is validated, then the door opens and the data timestamped and saved in a local and online server, else the door remains locked. Using RFID tag is more accurate than other biometric means of its high authentication because of its accuracy of detection.

Key words: RFID, Raspberry pi, RC522, stepper motor, biometric data.

Research Article

Full original manuscript

Isolation of a pentacyclic triterpenoid from Sceletium tortuosum

Itumeleng B.Setshedia*, Martin Myera, John Dewara and Gerda Foucheb*
aCollege of Agriculture and Environmental Sciences, University of South Africa, Florida Park, Johannesburg, Gauteng, South Africa
bDepartment of Chemistry, University of Pretoria, Hatfield, Pretoria, Gauteng, South Africa

Abstract

Traditionally, extracts from Sceletium tortuosum have been used, both as a medicine as well as for social and spiritual purposes. The genus is distributed in the south-western parts of South Africa. Methanolic extracts of S. tortuosum were prepared and fractionated using column chromatography. Indole alkaloids have been reported from S.  tortuosum with mesembrine as the most abundant alkaloid and mesembrenone, 4’-odemethylmesembrenol and tortuosamine also present. A triterpenoid, novel to this genus was isolated and reported for the first time. NMR and HPLC-MS/MS analyses were used to confirm the structure of the compound.

Key words: Sceletium tortuosum, alkaloids, triterpenoid, obtusalin.

Research Article

Full original manuscript

Factors affecting the global diffusion of an African animal genetic resource: the case study of the Cameroon Blackbelly sheep

Meka zibi II. M.A*., Meutchieye. F*., Ntsoli. J., Tadakeng Y., Fonteh .F
Department of Animal Science, FASA; University of Dschang P.O. Box 188, Dschang Cameroon

Abstract

Sheep farming is a vital component in the food, economic and socio-cultural security of many countries around the world. Sheep are present in most countries of the world, proving their adaptation capacities to different climatic conditions and agro-ecological zones in different countries. Because of these capabilities, they have been widely disseminated in order to enhance their genetic potential. Several elements have contributed to the diversification and dissemination of this biodiversity, including the human slave trade waves. During these movements, Cameroon ovine biodiversity has been exported and distributed throughout the world, particularly the Blackbelly sheep breed. Within the framework of the World Action Plan focusing on the characterization of native biodiversity, it is important to trace the dispersal routes and models of this particular breed across the world in order to demonstrate the impact of slave trade in the dissemination of animal material, but also to collect information on the ways of adaptation and exploitation of the Blackbelly sheep around the world. This could enable the conservation and better improvement of this genetic resource in Cameroon for the benefit of population. From publications collected on the matter around the world, it appears that slave trade and the triangular trades were the main factors of global diffusion of the Cameroon Blackbelly sheep. The Blackbelly has been spread in two continents: America and Europe, but its main settling area was the Caribbean. The Barbaric Island was the main point of adaptation of this breed hence the name Barbados Blackbelly from which several countries have refueled. The Blackbelly sheep has been adopted as an official breed after improvement in 4 countries: Barbaric Island (Barbados Blackbelly), the United States (American Blackbelly), Germany (Kamerun Schafe), and in Martinique (Martinik Sheep). All these varieties share some specific features that have remained very close to that of the sheep of Cameroon notably: the brown coat color with a blackbelly, resistance to diseases (trypano-tolerant), hardy, and prolific. Worldwide, the Blackbelly sheep is exploited for meat, leather, prestige, ecotourism and milk in some extent. The current state of information on Blackbelly in Cameroon is limited to descriptive study and some phenotypic assessment. In-depth studies on its mode of exploitation and its molecular genetics will certainly allow better understanding of this breed to plan for methods of conservation and sustainable improvement.

Key words: Blackbelly sheep, colonization, international trade, biodiversity, Cameroon

Research Article

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The 3D printing of moulds used in injection moulding processing

Brando Okolo

Apium Additive Technologies GmbH – Siemensalle 84, Karlsruhe D76187, Germany

Abstract

The possibility of using additive manufacturing methods such as 3D printing for the fabrication of moulds used in injection moulding processing has been discussed in this report. Two case studies depicting the benefits and draw-backs of such a fabrication approach for moulds are presented. The role of materials in creating engineering advantage for the performance of 3D printed moulds is also presented. The case studies showed that there is significant economic value in using 3D printing to fabricate moulds for small series runs on injection moulding machines rather than using moulds fabricated from milling methods.

Key words: 3D printing, additive manufacturing, injection moulding, carbon fibre, PEEK

Research Article

Full original manuscript

Preserving Cameroon’s Cultures and Traditions (CAMCT)  Using App and Cloud Computing

Rochelle Pacio, Nelly-Anne Shurri Ndikum, Russelle Steranova Kenge
Department of Computing and Software Engineering, PKFokam Institute of Excellence; Yaounde, Cameroon

Abstract

In today’s world, people are addicted to their mobile devices due to its interactive features. Multimedia plays an important role on why people keep using their mobile technologies to gather information through the combination of text with video, animation, audio, graphic and virtual reality.  This study aimed to develop an app and use cloud computing for storage. This app will greatly help in disseminating consistent information from one generation to another. Also, it will boost cultural tourism and innovate museums as tourists and locals will enjoy the use of this app while knowing everything about Cameroon. The methodology used for this study was Rapid Application Development (RAD) designed to provide quick software methodology that involves iterative development and quick construction of prototypes.

Key words: Cultures and Traditions, Multimedia Elements, Apps, Cloud Computing

Research Article

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Urbanization, CO2 Emissions, and Science-Technology-Society in Cameroon

Jacob TCHE1,2*, Nana Alex Roosevelt2 ,  Tedonfouet N. Aliance2
1University of Yaounde II , 2PKFokam Institute of Excellence

Abstract

Important advances have been made in theoretical and econometric research in the relationship between CO2 and urbanisation. However, scanty attention has been focussed on the role and importance of science and technology as one of the major factors reducing CO2 emissions. For example, to our knowledge, Cameroon has never been chosen as a case study. Therefore, the statistical and econometric analyses undertaken in this paper aims at filling this gap. We begin our analysis by employing statistical tools and econometric tests such as unit root tests, Cointegration tests, Error Correction tests and the Granger short and long run causality tests. Our results related to the causal relationship between CO2, urbanization and science and technology indicate that while there is a bidirectional causality between the latter variables in the long run, there is no causality between the studied variables in the short run.

Key words: Urbanization, CO2 emissions, science and technology and ecological modernization

Analysis

Les nouvelles guerres industrielles.

Hakim Ben Hammouda.

Le débat sur les politiques industrielles a connu ces derniers mois des développements majeurs au niveau international tant dans le débat économique que dans les politiques publiques. Le débat économique a connu une rupture majeure dans les positions défendues par les économistes depuis le début des années 1980 et le consensus qui avait prévalu faisant des politiques industrielles les « excommuniés » d’une discipline en quête obsessionnelle de scientificité et de reconnaissance. Ces politiques qui étaient au centre des efforts de reconstruction d’après-guerre et postcoloniale dans le monde depuis la fin de la seconde guerre mondiale a été battu en brèche par la contre-révolution néolibérale du début des années 1980 qui a emporté avec elle toute forme d’interventionnisme étatique en faisant l’héritage désuet d’un monde post-moderne en pleine décrépitude. Désormais, c’est au marché et à la libre concurrence de prendre en charge la répartition des ressources rares, l’Etat devrait se limiter à son rôle de régulateur de l’activité économique.