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1. A Retention Ability of Velocity Profile in Multi-Stage Fluidization Systems

Author

Shabri, M. S. M., Nawi, M. A. M., Zakaria, M. S., Musa, N. M., Alias, M. A. R., Ibrahim, R. M. Z. R., Angrisani, Leopoldo, Series Editor, Arteaga, Marco, Series Editor, Panigrahi, Bijaya Ketan, Series Editor, Chakraborty, Samarjit, Series Editor, Chen, Jiming, Series Editor, Chen, Shanben, Series Editor, Chen, Tan Kay, Series Editor, Dillmann, Rüdiger, Series Editor, Duan, Haibin, Series Editor, Ferrari, Gianluigi, Series Editor, Ferre, Manuel, Series Editor, Hirche, Sandra, Series Editor, Jabbari, Faryar, Series Editor, Jia, Limin, Series Editor, Kacprzyk, Janusz, Series Editor, Khamis, Alaa, Series Editor, Kroeger, Torsten, Series Editor, Li, Yong, Series Editor, Liang, Qilian, Series Editor, Martín, Ferran, Series Editor, Ming, Tan Cher, Series Editor, Minker, Wolfgang, Series Editor, Misra, Pradeep, Series Editor, Möller, Sebastian, Series Editor, Mukhopadhyay, Subhas, Series Editor, Ning, Cun-Zheng, Series Editor, Nishida, Toyoaki, Series Editor, Pascucci, Federica, Series Editor, Qin, Yong, Series Editor, Seng, Gan Woon, Series Editor, Speidel, Joachim, Series Editor, Veiga, Germano, Series Editor, Wu, Haitao, Series Editor, Zamboni, Walter, Series Editor, Zhang, Junjie James, Series Editor, Md. Zain, Zainah, editor, Sulaiman, Mohd. Herwan, editor, Mohamed, Amir Izzani, editor, Bakar, Mohd. Shafie, editor, and Ramli, Mohd. Syakirin, editor

Published
2022
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2. Effect of Nozzle Diameter on Temperature Behavior in Spray Dryer Via Computational Fluid Dynamics

Author

Alias, M. A. R., Sarip, M. S. M., Mustafa, W. A., Nawi, M. A. M., Yang, L. W., Samat, A. A., Raja Ibrahim, R. M. Z., Shabri, M. S. M., Angrisani, Leopoldo, Series Editor, Arteaga, Marco, Series Editor, Panigrahi, Bijaya Ketan, Series Editor, Chakraborty, Samarjit, Series Editor, Chen, Jiming, Series Editor, Chen, Shanben, Series Editor, Chen, Tan Kay, Series Editor, Dillmann, Rüdiger, Series Editor, Duan, Haibin, Series Editor, Ferrari, Gianluigi, Series Editor, Ferre, Manuel, Series Editor, Hirche, Sandra, Series Editor, Jabbari, Faryar, Series Editor, Jia, Limin, Series Editor, Kacprzyk, Janusz, Series Editor, Khamis, Alaa, Series Editor, Kroeger, Torsten, Series Editor, Li, Yong, Series Editor, Liang, Qilian, Series Editor, Martín, Ferran, Series Editor, Ming, Tan Cher, Series Editor, Minker, Wolfgang, Series Editor, Misra, Pradeep, Series Editor, Möller, Sebastian, Series Editor, Mukhopadhyay, Subhas, Series Editor, Ning, Cun-Zheng, Series Editor, Nishida, Toyoaki, Series Editor, Pascucci, Federica, Series Editor, Qin, Yong, Series Editor, Seng, Gan Woon, Series Editor, Speidel, Joachim, Series Editor, Veiga, Germano, Series Editor, Wu, Haitao, Series Editor, Zhang, Junjie James, Series Editor, Isa, Khalid, editor, Md. Zain, Zainah, editor, Mohd-Mokhtar, Rosmiwati, editor, Mat Noh, Maziyah, editor, Ismail, Zool H., editor, Yusof, Ahmad Anas, editor, Mohamad Ayob, Ahmad Faisal, editor, Azhar Ali, Syed Saad, editor, and Abdul Kadir, Herdawatie, editor

Published
2022
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3. Influence of Nozzle Diameter Towards Velocity Distribution in Spray Dryer Via Computational Fluid Dynamics

Author

Alias, M. A. R., Sarip, M. S. M., Nawi, M. A. M., Mustafa, W. A., Yang, L. W., Samat, A. A., Raja Ibrahim, R. M. Z., Shabri, M. S. M., Angrisani, Leopoldo, Series Editor, Arteaga, Marco, Series Editor, Panigrahi, Bijaya Ketan, Series Editor, Chakraborty, Samarjit, Series Editor, Chen, Jiming, Series Editor, Chen, Shanben, Series Editor, Chen, Tan Kay, Series Editor, Dillmann, Rüdiger, Series Editor, Duan, Haibin, Series Editor, Ferrari, Gianluigi, Series Editor, Ferre, Manuel, Series Editor, Hirche, Sandra, Series Editor, Jabbari, Faryar, Series Editor, Jia, Limin, Series Editor, Kacprzyk, Janusz, Series Editor, Khamis, Alaa, Series Editor, Kroeger, Torsten, Series Editor, Li, Yong, Series Editor, Liang, Qilian, Series Editor, Martín, Ferran, Series Editor, Ming, Tan Cher, Series Editor, Minker, Wolfgang, Series Editor, Misra, Pradeep, Series Editor, Möller, Sebastian, Series Editor, Mukhopadhyay, Subhas, Series Editor, Ning, Cun-Zheng, Series Editor, Nishida, Toyoaki, Series Editor, Pascucci, Federica, Series Editor, Qin, Yong, Series Editor, Seng, Gan Woon, Series Editor, Speidel, Joachim, Series Editor, Veiga, Germano, Series Editor, Wu, Haitao, Series Editor, Zhang, Junjie James, Series Editor, Isa, Khalid, editor, Md. Zain, Zainah, editor, Mohd-Mokhtar, Rosmiwati, editor, Mat Noh, Maziyah, editor, Ismail, Zool H., editor, Yusof, Ahmad Anas, editor, Mohamad Ayob, Ahmad Faisal, editor, Azhar Ali, Syed Saad, editor, and Abdul Kadir, Herdawatie, editor

Published
2022
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4. Waste biomass densification for thermochemical conversion

Author

Ibrahim, R. M., Stegemann, J., and Borrion, A. L.

Subjects
662
Abstract

Waste biomass densification into briquettes and pellets improves the characteristics of loose biomass residue for efficient transport, storage and thermochemical conversion into advanced fuels (e.g., syngas, for electricity, liquid fuels and chemicals). Briquettes of good and consistent quality are required but often difficult to achieve as more work is still required to understand how the chemical and physical properties of different biomass types, along with process variables, affect their quality. Also, the additional energy and cost associated with biomass briquetting has raised the issue of the sustainability of briquetting loose biomass before its conversion. This research focuses on the use of novel approaches to improve the quality of fuel briquettes for thermal applications, and further evaluates the sustainability of fuel briquetting, using life cycle assessment (LCA). Experiments were conducted to investigate the potential benefits of blending waste rice husks, corn cobs and bagasse, and with novel binders including enhanced treated biosolids, and microalgae (Chlorella sorokiniana), on fuel briquette properties, using factorial design methods. The new binders were also compared with existing starch binder. The range of briquettes produced in this study had unit densities of up to 3.3 times the loose biomass bulk density, and were stronger than briquettes from the individual biomass materials. Considering average values from two biomass sources, an unconfined compressive strength of 176 kPa was achieved at a compaction pressure of 31 MPa for a 3:7 blend of rice husks to corn cobs with 10% binder (starch + water). These briquettes were durable, with only 4% mass loss during abrasion, and 10% mass loss during shattering, tests. They absorbed 36% less water than loose corn cobs. An unconfined compressive strength of 175 kPa was also achieved for a 2:4:1 blend of rice husks, corn cobs and bagasse with 17% binder (microalgae), also at a compaction pressure of 31 MPa. The statistical analysis of the above results showed that the source of the biomass had a significant effect on densification, which emphasises the need to understand factors underlying biomass variability. Of all the briquettes produced with the three binders, those containing the microalgae binder were found to be most durable, with a higher energy density, slower mass loss during briquette combustion, and a higher afterglow time. Since microalgae may be grown using CO2 from biomass combustion, discovery of their advantages as a binder in briquetting is particularly welcome. To evaluate the sustainability of fuel briquetting, a detailed review of the existing LCA studies on fuel briquetting was carried out. These were found to provide insufficient and inconsistent information, due to different choices in system boundary, data sources, functional unit, allocation procedure, briquetting technology and biomass/briquette properties. An LCA model of biomass briquetting was therefore developed to enable transparent comparison of life cycle environmental impacts of briquetting with individual or blends of biomass feeds with a variety of technological options. The main model components include materials and process inventory databases derived from standard sources, main process calculations, user inputs and results sections. The model is open-access in a user accessible format (Microsoft Excel). A representative case study with mixed rice husks and corn cobs showed that the briquetting unit itself made the largest contribution, 42%, to the total life cycle operational energy of the briquetting system. For all the blends of rice husks and corn cobs explored in this study, the total life cycle energy of briquetting was in the range 0.2 to 0.3 MJ per MJ of fuel briquette energy content. Variation of the LCA input parameters in a sensitivity test for the same blend ratios, gave a range of total life cycle energy of briquetting from 0.2 to 1.7 MJ per MJ of fuel briquette energy content. This indicates that energy use in briquetting is not necessarily recovered, highlighting the need for continuous process optimisation and high quality LCA data. An increase in rice husks content of the blend increased the environmental impact of briquetting including the global warming potential (kg CO2-eq), acidification potential (kg SO2-eq), human toxicity (kg 1,4-DB-eq), ozone layer depletion (kg CFC-11-eq), and terrestrial ecotoxicity (kg 1,4-DB-eq) per MJ briquette energy content, as it was associated with a lower briquette density, which increased the energy required for handling.

Published
2017

7. Preliminary Study on Hard Ticks ( Acari: Ixodidae) of Sheep in Some Areas of Thamar Governorate, Yemen

Author

Ibrahim R. M. AL-Shaibani

Abstract

The objective of this study was to identify and determine the prevalence of tick species infesting sheep in some areas of Thamar governorate, Yemen. A total of 392 indigenous sheep breeds of either sex and different age were randomly selected and examined for presence of ticks using standard parasitological techniques from December, 2010 to May, 2011. The results revealed that the overall prevalence of tick infestations on sheep was 43.37 %. Of total 875 ticks collected, Seven species of ixodid ticks were identified. The species on hierarchy of overall prevalence abundance were Rhipicephalus sanguineus (13.01%), Rhipicephalus (Boophilus) decoloratus (9.69%), Rhipicephalus evertsi evertsi (5.87 %), Hyalomma marginatum (4.59 %), Amblyomma variegatum (4.34%), Rhipicephalus (Boophilus) annulatus (3.06%), Haemaphysalis sulcata (2.04%). Rhipicephalus (Boophilus) decoloratus species is recorded for first time in Thamar governorate and Yemen as well as. Statistically, there was significance difference (P

Published
2023

11. Influence of Zinc Manganite Nano Fillers on the Optical and Dielectric Features of Poly-Methyl Methacrylate/Multi-Walled Carbon Nanotubes Nanocomposites

Author

El-Naggar, A. M., Heiba, Zein K., Kamal, A. M., Ibrahim, R. M., and Mohamed, Mohamed Bakr

Abstract

Poly (methyl methacrylate, PMMA)/ multi-walled carbon nanotubes (MWCNTs)/ x wt %zinc manganite (ZnMn2O4) polymers were fabricated using co-precipitation and casting techniques. The structure of the filler and all polymers was determined with X-ray diffraction. The morphology of the polymer surfaces was explored by employing scanning electron microscopy. The direct and indirect band gap energies (Eg) of PMMA polymer (5.02, 4.44) eV decreased attaining minimum values (4.97, 3.41) eV upon the addition of MWCNTs and 2 wt% ZnMn2O4. The refractive index at 600 nm was increased from 1.33 (PMMA) to 1.55 (x = 2 wt% ZnMn2O4). The optical dielectric constant and optical conductivity displayed their highest values when the ZnMn2O4doping level reached 2 wt%. The PMMA/MWCNTs/x wt% ZnMn2O4polymers exhibited blue-violet colors on the CIE 1931 chromaticity diagram under excitation wavelength of 317 nm. The electrical dielectric constant and the AC conductivity attained their peak at the concentration of 2 wt% and 1 wt% ZnMn2O4, respectively. PMMA/MWCNTs/x wt% ZnMn2O4polymers possess controllable optical and electrical characteristics, thus making them potentially valuable optical materials for future optoelectronic or photocatalytic application development.

Published
2024
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12. An Insight into the Impact of Nano CuCo2O4Doping on the Optical and Dielectric Performance of PMMA/Carbon Nanoparticles

Author

El-Naggar, A. M., Heiba, Zein K., Kamal, A. M., Ibrahim, R. M., and Mohamed, Mohamed Bakr

Abstract

In the present study, novel functional properties were achieved for polymethyl methacrylate (PMMA) through loading with carbon nanoparticles (CNPs) as well as varying quantities of CuCo2O4nanoparticles. The blends obtained were subjected to different characterization techniques. Extensive investigations of different optical properties were carried out, covering linear and nonlinear optical properties. After the incorporation of CNPs/CuCo2O4in the host polymer matrix, the absorbance, reflectance and refractive index exhibited improvements, while continuous reductions in both direct and indirect optical band gap energies were observed. Significant improvements in the linear and nonlinear optical parameters were observed with increasing CuCo2O4doping levels. Dielectric measurements provided insights into the impact of CuCo2O4content on the ac conductivity, energy density, dielectric properties, and electric modulus across all blends. The sample doped with 1.5 wt% exhibited the highest dielectric constant. In conclusion, the optical and dielectric properties of the PMMA/CNPs/x wt% CuCo2O4blends make them promising candidates in optoelectronics and photocatalysis applications.

Published
2024
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13. Early storage root bulking index and agronomic traits associated with early bulking in cassava

Author

Rob Melis, Paul Shanahan, Ibrahim R. M. Benesi, Julia Sibiya, and Michael M. Chipeta

Subjects
0106 biological sciences, Index (economics), food and beverages, Soil Science, Sowing, Growing season, 04 agricultural and veterinary sciences, Biology, 01 natural sciences, Agronomy, Dry weight, Yield (wine), Shoot, Path coefficient, 040103 agronomy & agriculture, 0401 agriculture, forestry, and fisheries, Cultivar, Agronomy and Crop Science, 010606 plant biology & botany
Abstract

One of the attempts by farmers in counteracting the devastating effects of cassava brown streak disease (CBSD) on yield and quality of cassava is early harvesting. However, most varieties grown by farmers are often late bulking which increases the disease severity while on the other hand early harvesting results in significant yield losses. Farmers, therefore, need early storage root bulking cassava varieties in order to reduce the time to harvest leading to a faster rate of return to investment, while at the same time avoiding devastating effects of CBSD on yield and quality of cassava. The study was, therefore, conducted to identify high-yielding and early storage root bulking cassava genotypes as well as traits associated with early storage root bulking and estimate yield loss if any due to early harvesting. The overall aim was to generate information that would guide future improvement programmes for high-yielding and early-bulking cassava varieties in Malawi and other countries facing similar challenges. Trials were implemented using a square lattice design with three replications at two locations for two growing seasons with three harvest intervals (6, 9 and 12 months after planting, MAP). High yields were obtained of up to 9.5 t/ha at 6 and 17.8 t/ha at 9 MAP. Furthermore, the study revealed that yields obtained at 9 MAP were higher than those obtained at 12 MAP for some genotypes which suggests that such genotypes would be considered as early storage root bulking. Simple correlation analysis identified harvest index, storage root number, storage root diameter and storage root length as the selection criteria to achieve high fresh storage root yield (t/ha) and dry mass yield (t/ha). Path coefficient analysis allocated harvest index and shoot mass as the major selection criteria in improving fresh storage yield and dry mass yield. The study suggests that both source and sink capacities were important for determining early yield. Therefore, these two traits are the key determinants of early storage root bulking and should be used when selecting early-bulking cultivars and indirectly selecting for storage root number, storage root diameter and storage root length.

Published
2016

14. Farmers' knowledge of cassava brown streak disease and its management in Malawi

Author

Paul Shanahan, Ibrahim R. M. Benesi, Julia Sibiya, Michael M. Chipeta, and Rob Melis

Subjects
0106 biological sciences, Veterinary medicine, Incidence (epidemiology), Manihot esculenta, food and beverages, 04 agricultural and veterinary sciences, Disease, Biology, 01 natural sciences, Agronomy, Insect Science, 040103 agronomy & agriculture, 0401 agriculture, forestry, and fisheries, Viral disease, Agronomy and Crop Science, 010606 plant biology & botany
Abstract

There is little information on farmers’ knowledge about cassava (Manihot esculenta Crantz) brown streak disease (CBSD), despite extensive studies on incidences and severities. The objective of this study was to assess farmers’ knowledge of CBSD diagnosis and management. The study was conducted in three districts of Malawi by administering semi-structured interviews in combination with disease incidence and severity surveys. Farmers’ knowledge of disease diagnosis and management was associated with CBSD incidence and severity. High levels of knowledge about CBSD were observed in areas with high disease incidence. Only 10.1% of the farmers were capable of identifying the foliar symptoms of the disease. On average, 75.0% and 71.7% of the farms had leaf and storage root incidences, respectively. At harvest, 88.3% of the farmers’ fields exhibited storage root necrosis. CBSD leaf and storage root severities differed significantly (P < 0.001) from one district to the other and between varieties. Most far...

Published
2016

15. Temperature-dependency performance of InGaAsP semiconductor laser amplifiers.

Author

Ibrahim, R. M., Karomi, I. B., Ameen, O. F., and Al-Ghamdi, M. S.

Subjects
*DEBYE temperatures, *HIGH temperatures, *PHOTONICS
Abstract

We report a theoretical analysis on the influence of operation temperature on the static and dynamic properties of an InP/InGaAsP semiconductor Laser amplifier (SLA). We use a numerical wideband steady-state model and numerical algorithm, to study the (I-P) curves, gain bandwidth, noise figure, outpout noise power and outpout OSNR in a range between - 20 °C and 100 °C. InP/InGaAsP SLA exhibited a thershold curent as low as 55mA at 100 °C and the characteristic temperature (T0) of the SLA was found to be 142.8 0C, which confirms the high temperature operation of the device. Moreover, the results show that InP/InGaAsP SLA can cover 3dB operating at signal wavelengths between 1.54μm and 1.58μm with gains of up to 25dB at -20 0C. This peak slightly decreases with temperature. Furthermore, a high out power saturation of 7 dB was exhabited at -20 °C and a low noise figure of around 2.8 dB was achieved in the deviece. Finally, our model shows the elegant performance of InGaAsP/InP SLA in the range between -20 °C and 100 °C, which makes it a promising candidate for integrated photonics. [ABSTRACT FROM AUTHOR]

Published
2021
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17. Quantification of cassava mosaic geminiviruses and cassava brown streak viruses

Author

Musopole, Hastings Twalie, Labuschagne, Maryke T., Gowda, Maruthi M.N., Benesi, Ibrahim R. M., Minnaar-Ontong, Adré, Musopole, Hastings Twalie, Labuschagne, Maryke T., Gowda, Maruthi M.N., Benesi, Ibrahim R. M., and Minnaar-Ontong, Adré

Abstract

English: Cassava (Manihot esculanta Crantz) is a perennial woody plant which is cultivated in Africa, Asia and Latin America. It is tolerant to drought and grows in poor soils. It is a source of carbohydrates, vitamins and small quantities of proteins. In Malawi, it is the most important root crop and it is grown across the country. It is consumed as a staple food by 30% of the people living along the central and northern part of Lake Malawi. Its production is constrained by among others, diseases CMD and CBSD. These two diseases are known to spread through white flies. The magnitude of attack by the two diseases depends on the genotype and the environment. No released genotypes in Malawi have ever been evaluated in seed transmission of viruses’ studies. The experiment on the quantification of F1 cassava progenies from open pollinated F1 progeny crosses revealed that genotypes which show high severity of CMD are likely to allow rapid multiplication of EACMMV and SACMV. However, it has been proven that this might not always be the case as some genotypes may have higher virus quantities while showing slightly less severe symptoms. Genotypes which succumb to high disease symptom severity are likely to have high incidence of the disease. CMD symptom severity and incidence were positively correlated. The experiment on determination of virus quantities in different tissues has provided information that virus quantities in particular tissues depend on the cultivar used. The viruses can spread to all the tissues analysed in this research. It was shown that root parenchyma and leaf tissues accommodated most of CBSV and UCBSV in the cultivars used. When there was co-infection, CBSV and UCBSV were positively correlated. EACMMV and SACMV quantity can vary in cassava tissues depending on the cultivar. Leaves have shown to contain a relatively high quantity of the viruses. CBSV, UCBSV, EACMMV and SACMV symptoms were not observed in seedlings grown from seeds which were obtained f, Afrikaans: Cassava (Manihot esculanta Crantz) is ‘n meerjarige houtagtige plant wat verbou word in Afrika, Asië en Latyns Amerika. Dit is droogte tolerant en kan groei in swak grond. Dit is ‘n bron van koolhidrate, vitamines en klein hoeveelhede proteïene. Dit is die belangrikste wortelgewas in Malawi, en dit groei oral in die land. Dit word as stapelvoedsel gebruik deur 30% van die mense wat woon langs die sentrale en noordelike dele van die Malawi meer. Cassava produksie word beperk deur, onder andere, die siektes CMD en CBSD. Hierdie twee siektes word versprei deur witvlieë. Die erns van die infeksie deur hierdie twee siektes hang af van die genotipe en die omgewing. Inligting oor die reaksie van verskillende Malawi genotipes en hulle nageslag aangaande akkumulasie van virusse, is baie beperk. Geen vrygestelde genotipes in Malawi is nog ooit geëvalueer vir saadoordrag van virusse nie. Die eksperiment oor die kwantifikasie van cassava F1 nageslag van oop en spesifieke kruisings het getoon dat genotipes met ‘n hoë vlak van CMD ‘n vinnige vermeerdering van SACMV toelaat. Dit is egter bewys dat dit nie altyd die geval is nie, omdat sekere genotipes groter hoeveelhede virus gehad het terwyl hulle steeds minder simptome getoon het; daar was dus geen korrelasie tussen min simptome van SACMV en CMD en virus insidensie nie. Genotipes wat baie siektesimptome gehad het egter hoë virus insidensie getoon; dus was die graad van die siekte met die insidensie gekorreleer. Die eksperiment vir die bepaling van virus hoeveelhede in verskillende weefseltipes het getoon dat virus hoeveelhede in spesifieke weefsel afhang van die cultivar wat gebruik is. Virusse het versprei na alle weefsel wat in die studie geanaliseer is. Wortel parenkiem weefsel het meeste van die CBSV en UCBSV in die cultivars gehuisves. Waar daar ko-infeksie was, was CBSV en UCBSV positief gekorreleer. SACMV hoeveelheid het gewissel tussen die wortel parenkiem, wortel korteks en stam korteks (5 cm van bo), afhange

Published
2016

20. Actividad antioxidante de extractos fenólicos de tortas de semillas de kenaf (Hibiscus cannabinus)

Author

Ismail, N., Ismail, M., Ibrahim, R. M., and Mariod, A. A.

Subjects
hibiscus cannabinus, Polyphenols composition, Nutrition. Foods and food supply, Composición de polifenoles, antioxidant activity, Kenaf seedcake, lcsh:TX341-641, Torta de semilla de kenaf, kenaf seedcake, Antioxidant activity, polyphenols composition, Hibiscus cannabinus, TX341-641, Actividad antioxidante, lcsh:Nutrition. Foods and food supply
Abstract

The antioxidant activities of kenaf seedcake methanolic extract (CME) and fractions obtained from it using ethyl acetate (EAF), hexane (HF) and water (WF) were investigated. Total phenolic contents were 64.5, 36.1, 31.3 and 14.6 mg gallic acid equivalent/g dry weight in EAF, CME, WF, and HF, respectively. Kenaf seedcake extract/fractions showed inhibitory activity of β-carotene bleaching and corn oil oxidation. Also, the extract/fractions were scavenged for the 1,1-diphenyl-2-picrylhydrazyl radical. The EAF extract showed the highest DPPH radical scavenging activity followed by the CME, WF and HF extracts. Therefore, the rich phenolic fractions of kenaf seedcake may represent a potential source of natural antioxidants. The predominant phenolic compounds identified by HPLC-DAD in CME and HF extracts were gallic, (+)-catechin, chlorogenic, hydroxybenzoic, syringic, and vanillin.Se ha investigado la actividad antioxidante de extractos metanólicos procedentes de tortas de semillas de kenaf (CME) y de las fracciones obtenidas usando acetato de etilo (EAF), hexano (HF) y agua (WF). Los contenidos fenólicos totales fueron 64,5, 36,1, 31,3 y 14,6 mg de equivalente de ácido gálico/g de peso seco, en EAF, CME, WF, y HF, respectivamente. Los extractos/fracciones de semillas de kenaf mostraron actividad inhibitoria de blanqueo del β-caroteno y oxidación del aceite de maíz. Además, los extractos/fracciones fueron captadores de radicales del 1,1-difenil-2-picrilhidrazil. El extracto EAF mostró la mayor actividad captadora de radicales de DPPH seguido por los extractos de CME, WF y HF. Por lo tanto, las fracciones ricas en fenoles de las tortas de semilla de kenaf pueden representar una fuente potencial de antioxidantes naturales. Los compuestos fenólicos predominantes identificados mediante HPLC-DAD en extractos de CME y HF fueron gálico, (+)-catequina, ácido clorogénico, hidroxibenzoico, siríngico, y vainillina.

Published
2012
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21. GENOTYPE X ENVIRONMENT INTERACTION AND STABILITY ANALYSIS OF CASSAVA GENOTYPES AT DIFFERENT HARVEST TIMES.

Author

Chipeta, Michael M., Melis, Rob, Shanahan, Paul, Sibiya, Julia, and Benesi, Ibrahim R. M.

Subjects
GENOTYPE-environment interaction, CASSAVA growing, CASSAVA yields, HARVESTING, ANALYSIS of variance
Abstract

Cassava (Manihot esculenta Crantz) like most other crops responds to the effect of genotype by environment interaction (GEI), which makes it difficult to identify the superior genotypes in terms of performance, stability and adaptability. Currently there is limited information about the adaptability of cassava genotypes at different times of harvesting (TOH). Due to increasing demand for early storage root bulking varieties, and confounding effects of site, crop age, and season during selection, there is a need for the objective characterization of genotypes in terms of adaptability and stability with respect to TOH. The study was, therefore, conducted to identify high yielding, stable and adaptable cassava genotypes at different times of harvesting (6, 9 and 12 months after planting, MAP) through the application of multivariate analysis techniques. The study was conducted in four environments using sixteen genotypes using a triple lattice design. Variance components for individual environment were analysed using Restricted Maximum Likelihood (REML) while combined analysis was performed using Additive Main effects and Multiplicative Interaction (AMMI) model. The AMMI analysis of variance at three TOH revealed that variances due to genotypes, environments, and GEI were significant for most of the traits. However, at 6 MAP, GEI was not significant for most of the traits. Significance of main effects indicated stability of some genotypes across environments while GEI significance indicated that some genotypes were specifically adapted to certain environments. The non-significance of GEI at 6 MAP for almost all traits means that genotypes can be reliably evaluated in any single environment. Selection of a) high yielding genotypes based on mean performance, b) stable genotypes based on GSI (mean performance and ASV) and c) adaptability of genotypes based IPCA1 versus IPCA2 identified five genotypes (Mulola, Phoso, Maunjili, Beatrice and Unknown) that exhibited consistent performance, stability and adaptability across the three harvest periods. These genotypes are therefore best candidates for production in any of the studied and other similar environments. [ABSTRACT FROM AUTHOR]

Published
2017

22. Genetic diversity analysis and nutritional assessment of cocoyam genotypes in Malawi

Author

Mwenye, Obed John, Labuschagne, Maryke T., Herselman, Liezel, Benesi, Ibrahim R. M., Mwenye, Obed John, Labuschagne, Maryke T., Herselman, Liezel, and Benesi, Ibrahim R. M.

Abstract

English: Cocoyam (C. esculenta (L.) Schott and X. sagittifolium (L.) Schott) belongs to the family Araceae. Cocoyam has the potential to contribute significantly to world agriculture in terms of food, nutrition and crop diversification. Despite this the crop remains neglected in terms of research focus. Limited or no information exists on the prevalence, preference and utilisation as well as the pattern and level of diversity that exists in cocoyam germplasm found in Malawi. This study determined the level and pattern of genetic diversity of cocoyam from Malawi using ethno-botany, morphological characters and AFLP markers. Mineral composition of selected genotypes was also determined. The ethno-botanical survey showed that farmers in Malawi maintain a large amount of cocoyam germplasm. These farmers have rich ethno-botanical and ecological knowledge of the cocoyam cultivars they conserve. Farmer’s preferences regarding cocoyam cultivars included uses of plant parts, adaptation and eating quality. Morphological characters showed high levels of variation among accessions. Two main species of cocoyam, Colocasia and Xanthosoma were identified based on leaf base shapes (petiole attachment). AFLP markers showed low levels of genetic diversity between accessions as opposed to the high morphological diversity. A combined (morphological characters and AFLP data) analysis using UPGMA clustering, PCA and AMOVA further alluded to the presence of the two cocoyam species within the germplasm. High levels of variation were detected between the two species and low levels of variation were observed within each of the two species (Colocasia and Xanthosoma). The PCA exhibited a better representation of the genetic diversity pattern than the hierarchical clustering. Accessions showed high levels of mineral composition. Potassium was identified as the major mineral component. Accessions also exhibited high levels of essential minerals (Ca, Fe and Zn). Incorporating cocoyam into the diet, Afrikaans: Amadumbie (C. esculenta (L.) Schott en X. sagittifolium (L.) Schott) behoort aan die Araceae familie. Amadumbie het die potensiaal om betekenisvol tot wêreldlandbou in terme van voedsel, voedingswaarde en gewasdiversifikasie by te dra. Ten spyte hiervan word die gewas nog steeds in terme van navorsing afgeskeep. Beperkte of geen inligting is oor die voorkoms, voorkeure en gebruik van die gewas sowel as die patroon en vlak van diversiteit wat voorkom in kiemplasma van Malawi beskikbaar. In hierdie studie is die patroon en vlak van genetiese diversiteit in amadumbie kiemplasma van Malawi met behulp van etnobotanie, morfologiese eienskappe en AFLP merkers bepaal. Minerale inhoud van geselekteerde genotipes is ook bepaal. Die etno-botaniese opname het getoon dat boere in Malawi ‘n groot hoeveelheid genotipes onderhou. Die boere wat die kiemplasma aanplant het ‘n ryk etno-botaniese en ekologiese kennis van die genotipes wat hulle bewaar. Die boere se voorkeur in terme van amadumbie cultivars sluit in die potensiële gebruik van plantdele, aanpassing en eetbaarheid. Morfologiese eienskappe het hoë vlakke van variasie tussen genotipes getoon. Die twee hoof spesies van amadumbie, Colocasia en Xanthosoma, is op grond van blaarbasis vorms (petiool aanhegting) geïdentifiseer. AFLP merkers het lae vlakke van diversiteit tussen genotipes getoon, wat teenstrydig was met die hoë morfologiese diversiteit. Gekombineerde analises (morfologiese eienskappe en AFLP data) met UPGMA groepering, PCA en AMOVA het die teenwoordigheid van twee amadumbie spesies in die kiemplasma bevestig. Hoë vlakke van variasie tussen die spesies en lae vlakke binne die twee spesies (Colocasia en Xanthosoma) is waargeneem. Die PCA het ‘n beter verteenwoordiging van die genetiese diversiteitspatrone as hierargale groepering gegee. Genotipes het hoë mineraalinhoudvlakke getoon. Kalium was die belangrikste minerale komponent. Genotipes het ook hoë vlakke van noodsaaklike minerale (Ca, Fe en Zn) gehad.

Published
2009

30. Antioxidant activity of phenolic extracts from kenaf (Hibiscus Cannabinus) seedcake.

Author

Mariod, A. A., Ibrahim, R. M., Ismail, M., and Ismail, N.

Subjects
*KENAF, *ANTIOXIDANT analysis, *POLYPHENOLS, *ETHYL acetate, *BETA carotene
Abstract

The antioxidant activities of kenaf seedcake methanolic extract (CME) and fractions obtained from it using ethyl acetate (EAF), hexane (HF) and water (WF) were investigated. Total phenolic contents were 64.5, 36.1, 31.3 and 14.6 mg gallic acid equivalent/g dry weight in EAF, CME, WF, and HF, respectively. Kenaf seedcake extract/fractions showed inhibitory activity of β-carotene bleaching and corn oil oxidation. Also, the extract/fractions were scavenged for the 1,1-diphenyl-2-picrylhydrazyl radical. The EAF extract showed the highest DPPH radical scavenging activity followed by the CME, WF and HF extracts. Therefore, the rich phenolic fractions of kenaf seedcake may represent a potential source of natural antioxidants. The predominant phenolic compounds identified by HPLC-DAD in CME and HF extracts were gallic, (1)-catechin, chlorogenic, hydroxybenzoic, syringic, and vanillin. [ABSTRACT FROM AUTHOR]

Published
2012
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32. UV-Irradiation Effects on the Structural, Optical and Electrical Characteristics of Soft Blended Polymeric Materials Loaded with Multi-Walled Carbon Nanotubes (MWCNTs)

Author

Abdel-Kader, Mohamed H., Mohamed, Mohamed Bakr, Alharby, T., and Ibrahim, R. M.

Abstract

AbstractUndoped and doped polyvinylpyrrolidone/carboxy-methyl cellulose/zinc sulfide/nickel oxide (PVP/CMC/ZnS/NiO) nanocomposite blends with multi-walled carbon nanotubes (MWCNTs) were prepared using sol-gel and solid-state reactions and casting techniques. Various blends were formed and their composition and morphologies were characterized using X-ray diffraction (XRD) and scanning electron microscope (SEM) techniques. The structures of the nano-fillers were examined using the XRD technique. The influence of the concentrations of MWCNTs on the linear and nonlinear optical parameters of PVP/CMC/ZnS/NiO nanocomposite blends was examined. The optical band gap energies were decreased from (direct, indirect: 5.31, 5.06) eV for undoped blends to 4.38 and 3.34 eV for the blends doped with the highest concentration of MWCNTs (0.15 wt%). The refractive indices of the various blends were calculated based on the obtained optical band gap energies using various models. The effect of MWCNTs concentrations on the dielectric constants, energy density, electric modulus and ac conductivity at room temperature of the PVP/CMC/0.5ZnS-0.5NiO/x wt% MWCNTs samples were explored using an Inductance, L, Capacitance, C, and Resistance, R (LCR) meter bridge. [ABSTRACT FROM AUTHOR]

Published
2024
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33. Innovatively feasible wet incipient method for preparing Cu doped TiO 2 nanocomposite: Electro-optical measurement supported by quantitative quantum and classical calculations.

Author

Bashal AH, Al-Refai H, Ibrahim RM, and Zaki AA

Abstract

The Cu-doped titanium oxide (Cu/TiO 2 ) nanocomposite was systematically prepared using the innovatively feasible incipient wet impregnation method. Notably, the samples were derived from the raw materials through water dilution only. The successful formation of the host anatase TiO 2 phase was confirmed by the characteristic peaks observed in the acquired X-ray powder diffraction (XRD) spectrum, which displayed intense peaks attributed to Cu 2+ scattering sites, indicating the formation of crystallite Cu/TiO 2 nanostructures. Dielectric measurements revealed that Cu/TiO 2 possesses a higher dielectric permittivity compared to undoped TiO 2 . The conductivity for both structures exhibited a decreasing trend with increasing temperature. Interestingly, the measured optical properties indicated that Cu/TiO 2 exhibited the minimum energy gap and maximum refractive index. This was further validated by qualitative time-dependent density functional calculation on a stable structural model, which was confirmed through semi-empirical molecular dynamic calculations. Thus, we have demonstrated the capability of our innovatively feasible synthesis method to produce the industrially important Cu-doped TiO 2 ., Competing Interests: The authors declare the following financial interests/personal relationships which may be considered as potential competing interests:Ali H. Bashal reports financial support was provided by 10.13039/501100002403Taibah University. Ali H. Bashal reports a relationship with Taibah University that includes: employment. No other activity If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 The Authors.)

Published
2024
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34. The effect of body condition score at calving and supplementation with Saccharomyces cerevisiae on milk production, metabolic status, and rumen fermentation of dairy cows in early lactation.

Author

Al Ibrahim RM, Kelly AK, O'Grady L, Gath VP, McCarney C, and Mulligan FJ

Subjects
Animal Nutritional Physiological Phenomena, Animals, Cattle metabolism, Dietary Supplements, Energy Metabolism, Female, Fermentation, Milk metabolism, Body Constitution, Cattle physiology, Lactation physiology, Postpartum Period physiology, Rumen metabolism, Saccharomyces cerevisiae metabolism
Abstract

The objective of this study was to examine the effects of live yeast (LY) supplementation and body condition score (BCS, 1-5 scale) at calving on milk production, metabolic status, and rumen physiology of postpartum (PP) dairy cows. Forty Holstein-Friesian dairy cows were randomly allocated to a 2 × 2 factorial design and blocked by yield, parity, BCS, and predicted calving date. Treatments were body condition at calving (low for BCS ≤3.5 or high for BCS ≥3.75; n=20) and supplementation with LY (2.5 and 10 g of LY/d per cow for pre- and postcalving, respectively; control, no LY supplementation; n=20). The supplement contained 10(9) cfu of Saccharomyces cerevisiae/g (Yea-Sacc(1026) TS, Alltech Inc., Nashville, TN). Daily milk yield, dry matter intake, milk composition, BCS, body weight, and backfat thickness were recorded. Blood samples were harvested for metabolite analysis on d 1, 5, 15, 25, and 35 PP. Liver samples were harvested by biopsy for triacylglycerol (TAG) and glycogen analysis on d 7 precalving, and on d 7 and 21 PP. Rumen fluid was sampled by rumenocentesis for all cows on d 7 and 21 PP. Supplementation with LY had no effect on milk yield, dry matter intake, rumen fluid pH, or blood metabolites concentration of dairy cows with high or low BCS at calving. Feeding LY increased rumen acetate proportion and protozoal population, tended to increase liver glycogen, and decreased rumen ammonia nitrogen during early lactation. Over-conditioned cows at calving had greater body reserve mobilization and milk production and lower feed intake, whereas cows with a moderate BCS at calving had greater feed intake, lower concentrations of nonesterified fatty acids and β-hydroxybutyrate, lower liver TAG and TAG:glycogen ratio, and faster recovery from body condition loss. Additionally, the data suggest that concentrations of liver enzymes in blood might be used as an indicator for liver TAG:glycogen ratio. Results indicate that in the case of this experiment, where the control treatment was associated with an acceptable rumen pH, feeding yeast did not significantly improve indicators of energy status in dairy cows., (Copyright © 2010 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.)

Published
2010
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35. The effect of immediate and delayed post space preparation and post length on the apical seal.

Author

Ibrahim RM, Seef RE, and Seniour SH

Subjects
Dental Leakage diagnosis, Electrochemistry, Glass Ionomer Cements therapeutic use, Gutta-Percha therapeutic use, Humans, Immersion, In Vitro Techniques, Root Canal Obturation methods, Root Canal Obturation statistics & numerical data, Time Factors, Tooth, Nonvital therapy, Post and Core Technique statistics & numerical data, Root Canal Filling Materials therapeutic use
Abstract

The purpose of this study was to investigate in vitro the effect of immediate and delayed post space preparation as well as the effect of remained length of gutta-percha on the apical seal of endodontically treated teeth obturated by lateral condensation technique using Ketac-Endo as root canal sealer. The apical seal was evaluated by measuring the microleakage using an electrochemical technique. It was found that, the degree of apical leakage is dependent on the length of post space preparation or the remained length of gutta-percha. Also the post space preparation should be delayed until maximum setting of Ketac-Endo root canal sealer.

Published
1995

36. Scanning and electron microprobe analysis of metal-porcelain interface.

Author

Ibrahim RM

Subjects
Dental Casting Technique, Microscopy, Electron, Scanning statistics & numerical data, Surface Properties, Dental Porcelain analysis, Electron Probe Microanalysis statistics & numerical data, Metal Ceramic Alloys analysis
Abstract

The purpose of this study was to analyze the interfacial region between porcelain and base metal alloy using scanning electron microscope with electron microprobe analyzer. Results gave evidence of formation of Nio and Cr2O3 with evidence of more migration of NiO towards the porcelain. Sandblasting of oxidized and fired metal samples (simulating firing of porcelain without its application) showed appearance of crystalline structure of Ni and Cragain, indicating delamination of oxide layer by sandblasting. At porcelain side analysis showed NiO and Cr2O3 and iron oxide plus Si, K, CI, Sn and Cu.

Published
1995

37. Effect of disinfectant on the dimensional stability, compressive strength and hardness on dental stone.

Author

Ibrahim RM

Subjects
Calcium Sulfate chemistry, Compressive Strength, Dental Casting Technique, Dental Materials chemistry, Drug Interactions, Drug Stability, Hardness, Hardness Tests methods, Materials Testing methods, Materials Testing statistics & numerical data, Time Factors, Calcium Sulfate pharmacology, Dental Disinfectants pharmacology, Dental Materials pharmacology
Abstract

In this investigation it was planned to study the effect of disinfection time on the dimensional stability, compressive strength and hardness of gypsum die materials. Measurements of specimens treated with disinfectant were compared with the corresponding measurements of control specimens. The results of this study indicated that there was no difference in the dimensional stability, compressive strength and hardness. Therefore using the disinfectants will not affect gypsum die material.

Published
1995

38. Recycling of calcium sulphate dihydrate.

Author

Ibrahim RM, Seniour SH, and Sheehab GI

Subjects
Dental Casting Technique, Differential Thermal Analysis statistics & numerical data, Equipment Reuse statistics & numerical data, Time Factors, X-Ray Diffraction, Calcium Sulfate analysis, Dental Casting Investment analysis
Abstract

This research was carried out to prepare dental stone from the previously fabricated stone casts. The study included reheating of the used casts at different conditions in an autoclave. Results indicated that calcium sulphate hemihydrate can be reproduced using the previously fabricated stone casts.

Published
1995

39. Electrochemical microleakage assessment of three different root canal obturation techniques.

Author

Ibrahim RM and Kataia M A-el-R

Subjects
Dental Leakage prevention & control, Electrochemistry, Gutta-Percha, Humans, In Vitro Techniques, Random Allocation, Root Canal Filling Materials, Root Canal Obturation instrumentation, Time Factors, Dental Leakage physiopathology, Root Canal Obturation methods
Abstract

This study compared microleakage of lateral condensation, Thermafil and multiphase gutta-percha obturation technique using an electrochemical test system. The mean leakage current of three obturation techniques compared with that of positive samples. It was found that, the multiphase gutta-percha showed the least mean leakage current followed by Thermafil and lateral condensation techniques.

Published
1994

40. Is psychotherapy really needed in nonwestern cultures? The case of Arab countries.

Author

Ibrahim AS and Ibrahim RM

Subjects
Adult, Child, Female, Gender Identity, Humans, Male, Personality Development, Saudi Arabia, Stress, Psychological complications, Cross-Cultural Comparison, Developing Countries, Health Services Needs and Demand trends, Psychotherapy trends
Abstract

Research has shown that mental health problems in Arab countries are of large proportion, with women and children probably the groups most at risk. Forms of psychological treatment are inadequate, making the need for such services a top priority.

Published
1993
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