430 research outputs found
Review of selected bio-wastes as potential materials for alkali-activation for cement-based products
There is growing need to finding alternative binder for Ordinary Portland Cement (OPC) as a result of the environmental hazards associated with its production. This paper presents the result of the review of selected bio-wastes as potential materials for alkali-activation in cement-based products. Studies carried out by several authors on the use of ashes from rice husk, cassava peel, sugarcane straw, corn cob and coconut shells were critically reviewed, while their chemical compositions as well as other criteria for alkali activation were identified. The review showed that the combined composition of SiO2, Al2O3 and Fe2O3 were in the ranges of 67.90 – 93.60, 46.59 – 72.25, 73.79 – 83.02, 41.13 – 78.30 and 71.3 – 77.57 % for rice husk ash, cassava peel ash, sugarcane straw ash, corn cob ash and coconut shell ash, respectively. These values met the requirement of ASTM 618 for materials to be considered as pozzolan, while the hydraulic coefficients of the ashes were also found comparable to notable industrial wastes that have been utilized for alkali-activation. It was also found that these materials are still not explored for alkali-activation. The paper concluded that the ash from these materials could be alkali activated to produce binders in cement-based products due to their potential properties.Keywords: Bio-wastes, alkali-activation, geopolymer, hydraulic activity coefficient, pozzola
RESERVIOR CHARACTERISTICS OF KHASIB FORMATION IN AMARA FIELD, SOUTHERN IRAQ
The Khasib Formation of Late Cretaceous (Upper Turonian – Lower Coniacian) is considered important reservoir in the Amara oil field.Knowledge of reservoirs rocks composition including fluid saturation and mineralogical components is essential for formation evaluations. The current study represents an evaluation study of the Khasib Formation using logs and cored data to evaluate the Khasib Formation in terms of its mineralogical, lithological composition and its petrophysical properties such as porosity and fluid saturation. Logs data of 15 drilled wells in the Amara Field and cored intervals of the well Am11 from the Khasib Formation were conventionally processed and integrated. Also, the mineralogical components of the Khasib Formation were revealed using a simultaneous equation approach by computer processed interpretation (CPI), where, combination of 5 logs including gamma ray, sonic, density, neutron and resistivity was integrated.The results show that the Khasib can be subdivided into upper and lower unit. It suggests that the Khasib Formation mainly consists of limestone with abundance of thin shale streaks concentrated at the upper parts. In addition, the lower part has an averaged porosity of about 0.185 (18.5%) and better hydrocarbon saturation, whereas, the upper part has recorded 0.121 (12.1%) averaged porosity. However, the lower part seems to be narrower than the upper part in terms of its thickness. The study furthermore, identified that the Khasib has deposited in a ramp setting during a transgression event caused by sea level change. Further study is needed to reveal the diagenesis process which affected reservoir quality of the Khasib Formation using petrographical techniques and to assess the Khasib Formation using the routine analysis techniques to detect directly porosity and permeability from plug samples
Bi-directional Beams Waveguide Slotted Antenna at Millimeter Wave
This paper focused on designing a bi-directional beams waveguide slotted antenna at millimetre wave spectrum. Waveguide slotted antenna is known for its highly directional pattern. By having bi-directional pattern, the capacity of system coverage can be expanded. The design is implemented by using antenna slot theory on a waveguide structure. The slotted are made on two wall surfaces and the performance is compared to the slotted on single wall. The two models designs are simulated using Computer Simulation Technology (CST) microwave software. The simulation results show that both models operate at 30 GHz with minimum reflection coefficient of -24.63 and -25.01 dB respectively. The two models achieved a fair high gain at 15.5 dB and 13.3 dB with directional beamwidth of 8.9 degree. The proposed bi-directional beams structure achieved a comparable gain in both directions when compared to the single direction
Access to digital materials on research output: Experience of Federal University Libraries users in northern states of Nigeria
This study examined access to digital materials on research output in some selected federal university libraries users in northern Nigeria. To achieve the goals, three objectives guided the study. Quantitative method and survey design were adopted to elicit data from lecturers and ICT librarians using close-ended questionnaire. A multi-stage sampling technique was used in selecting respondents from each institution. The data collected were analysed descriptively and the results were presented using frequency counts, mean and aggregate mean scores in tables. The findings revealed that access to digital materials influenced research output of library users with particularly to number of journal articles, conference papers presented, books, and chapters in books published. The choice of metadata type is determined by the number of modules such as administrative, technical, and preservation so as to resolve militating technical factors, promote information availability, interactive nature of technology, and portability of digital content. It could be concluded that access to digital materials and use immensely contributed to research output and metadata types, technical factors moderate access, adoption, use and research output in the selected federal universities in northern Nigeria. It is recommended that access and use of digital materials be prioritised for service effectiveness and efficiency on digital platforms supported by the libraries in the zone. Choice of metadata types should be based on possessing modules that support administrative, structural, technical, transformative procedures and preservation.
Keywords: Access; Digital materials; Research output; Experience; Federal University ; Library users; Northern Nigeri
MARSHALL PROPERTIES OF WASTE POLYMER AND NANOCLAY MODIFIED BITUMEN
Abstract. Polymer modified bitumen is emerging as one of the important construction materials for flexible pavements. The addition of polymers in bitumen improves the deformational stability and durability of bitumen. Also Montmorillonite nanoclay has been successfully used as additive in polymer to significantly improve the thermal stability and mechanical properties. The present study, the effect of waste low density polyethylene (LDPE), polypropylene (PP) obtained from waste carry bag, crumb rubber obtained from Waste tyre (CR)and nanoclay (MMT) on Marshall stability have been evaluated. Waste plastics, whose disposal is a matter of concern can be used successfully to modify the bitumen, these waste polymers are added in 2%, 4% and 6% whereas nanoclay is added in 1,2 and 3 % in 60/70 penetration grade bitumen and its effect on stability and flow of bitumen are evaluated. The result of experimental study shows that there is significant improvement in the Marshall Stability of bitumen due addition of waste polymer and nanoclay.Key Words: Waste Plastic, waste tyre, modified bitumen, Marshall stabilit
Morphoanatomy of striated myofibers in streptozotocin-induced diabetic wistar rats: assuaging effect of combined doses of Vernonia amygdalina and Azadirachta indica
Objective: This study aimed to evaluate the effects of Azadirachta indica and Vernonia amygdalina extracts on the morphoanatomy of striated myofibrils in diabetic rat models.
Methodology: Thirty Wistar rats randomly assigned into 5 groups of 6 rats/group were used. Group A received distilled water only, B (herbal) received A. indica (500 mg/kg/day) and V. amygdalina (400 mg/kg/day) simultaneously, C were diabetic rats, D were diabetic rats treated with herbal extracts combined and E, diabetic rats treated with metformin. Diabetes was induced with streptozotocin (70 mg/kg). Muscles glutathione peroxidase (GPx) and blood glucose levels were determined. The rats were sacrificed at the end of 60days treatment. The quadriceps femoris muscle harvested for histology.
Results: Diabetic herbal treated rats became euglycemic by the end of 8 weeks. GPx activity was significantly (p<0.05) elevated compared to control. The histology of skeletal muscle fibers of the diabetic rats treated with herbal formulation and metformin showed minimal level of damage.Conclusions: The findings in this study showed that the herbal formulation could be used in treatment of diabetes and in ameliorating the associated muscular cytoarchitectural alterations.
Keywords: diabetic, extract, glutathione, peroxidas
The effect of rutin on lipid profile and liver function enzymes on alloxan induced hyperglycaemic wistar rats
The aim of this research was to investigate the effects of rutin on lipid profile and liver function enzymes on alloxan induced hyperglycaemia in Wistar rats. Hyperglycaemic was induced by intraperitoneal injection of 150 mg/kg alloxan monohydrate. The rats were grouped into five groups of five rats each. Group 1 served as the diabetic negative control, Group 2 served as positive control and was treated with 2 mg/kg glibenclamide, while Groups 3, 4 and 5 were treated with 50, 100 and 200 mg/kg body weight of rutin respectively. Rutin was administered to the animals orally for a period of four weeks. At the end of the experimental period, the rats from each experimental group were sacrificed using light chloroform and sera were collected for the determination of lipid profile and liver function enzymes. There was a significant (p<0.05) decreased in the total cholesterol, triglyceride and low density lipoprotein as compared to control. However, there was a significant (p<0.05) increased in the level of high density lipoprotein when compared to diabetic control. Furthermore, there was a significant (p<0.05) decreased in the serum liver enzymes; Aspartate transaminase (AST) Alanine transaminase (ALT) and Alkaline phosphates (ALP) as compared to control. As regards to the reference drug 2mg/kg glibenclamide there was a significant (p<0.05) increased in the liver enzymes function as compared to control. Conclusion, rutin has hypolipidemic effect and also decreased liver function enzymes activity on alloxan induced hyperglycaemic rats.Keywords: Rutin, Hyperglycaemia, Alloxan, Lipid profile, Liver enzyme
Locally-processed cowpea husk improved body weight gain of on-farm raised rabbits in Northeastern Nigeria
Nigeria as an agricultural country generates a large tons of crop residues. Crop residues and by-products could result in environmental burden or pollution if not recycled or consumed by livestock. Efforts are being geared towards harnessing crop residues or by-products into animal feed. An on-farm experiment was conducted to investigate if fermentation and/or enzyme supplementation would improve the growth response of locally-reared rabbits. The weaner rabbits of similar age were sourced locally and were randomly distributed to groups. The animals were fed ad libitum with commercial basal diet but each treatment group was daily supplemented with 20 g of wheat bran, fermented wheat bran, fermented and enzyme-treated wheat bran, fermented wheat bran and fermented and enzyme-treated cowpea husk accordingly in a completely randomized design. Specific contrasts were also performed. Fermented cowpea husk improved (P<0.05) body weight (day 21) and body weight gain of experimental animals compared with the control group. Other treatments were statistically similar to the control group. The fermentation process improved body weight of experimental animals fed wheat bran diets. The fermentation process enhanced feed intake of experimental rabbits fed wheat bran over the animals fed unfermented wheat bran. Enzyme supplementation improved feed intake of the animals fed wheat bran-based diets. The small intestine of rabbits fed control diet showed normal mucosal layer with normal glands without inflammation (slender arrow), the villi appeared normal (white arrow). The small intestinal photomicrographs of rabbits fed fermented wheat bran-based diet showed mild necrosis and glandular degeneration (black arrow), and the circular muscle layer was normal (grey arrow). The photomicrographs of rabbits fed a fermented cowpea husk-based diet showed normal central venules. The study concluded that fermented cowpea husk could boost rabbit production.
Keywords: crop residue, nutrition, rabbit, sub-Saharan Afric
Morphological and ultrasonographic characterization of the three zones of supratesticular region of testicular artery in Assaf rams
[EN] To fully understand the histological, morphometrical and heamodynamic variations of different supratesticular artery regions, 20 mature and healthy Assaf rams were examined through ultrasound and morphological studies. The testicular artery images of the spermatic cord as shown by B-mode analysis indicated a tortuous pattern along its course toward the testis, although it tends to be less tortuous close to the inguinal ring. Doppler velocimetric values showed a progressive decline in flow velocity, in addition to pulsatility and vessel resistivity when entering the testis, where there were significant differences in the Doppler indices and velocities among the different regions. The peak systolic velocity, pulsatility index and resistive index were higher in the proximal supratesticular artery region, followed by middle and distal ones, while the end diastolic velocity was higher in the distal supratesticular region. The total arterial blood flow and total arterial blood flow rate reported a progressive and significant increase along the testicular cord until entering the testis. Histological examination revealed presence of vasa vasorum in the tunica adventitia, with their diameter is higher in the proximal supratesticular zone than middle and distal ones. Morphometrically, the thickness of the supratesticular artery wall showed a significant decline downward toward the testis; meanwhile, the outer arterial diameter and inner luminal diameter displayed a significant increase distally. The expression of alpha smooth muscle actin and vimentin was higher in the tunica media of the proximal supratesticular artery zone than in middle and distal ones.SIThe authors acknowledge the staff members and technicians of Comparative Anatomy and Pathology Department, and Animal Medicine and Surgery Department, Faculty of Veterinary Medicine, León University, Spain, and specially Professor P de Paz for their great help in the practical and laboratory parts of this study. Many thanks are extended to staff member of Anatomy and Embryology Department, Faculty of Veterinary Medicine, Sohag University, for their help with histological and morphometrical analyses. We are thankful and grateful for European Union for the financial support of this study through the project (ERASMUS+ KA107 2019/2020). This work was financially supported by the Junta de Castilla y León (LE253P18) and MINECO (AGL2017-83098-R) project and the University of León, and also by Sohag University, Egypt.This article was funded by Ministerio de Economía, Industria y Competitividad, Gobierno de España (AGL2017-83098-R) and Junta de Castilla y León (LE253P18)
First molecular analysis of rabies virus in Qatar and clinical cases imported into Qatar, a case report
Identifying the origin of the rabies virus (RABV) infection may have significant implications for control measures. Here, we identified the source of a RABV infection of two Nepalese migrants in Qatar by comparing their RABV genomes with RABV genomes isolated from the brains of a RABV infected camel and fox from Qatar
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