838 research outputs found
He-Ne Laser Irradiation Encourages reparative processes After cartilage loss in New Zealand rabbits
Many therapeutic methods used to encourage reparative processes of cartilage and accelerate their healing such as drugs, magneto-laser and so on. Twenty four adult New Zealand rabbits used in this study. They were divided in to two groups; control and treaded with He –Ne laser. A square skin flap done on the medial aspect of both auricles followed by pealing a square piece of cartilage from the auricle then the flaps sutured .The site of the operation in the rabbits of the treated group were irradiated with He –Ne laser 5mw power for seven days began after the operation directly. 3 rabbits from each group used for collection of specimens for histopathological examination at the 1, 2, 4 & 6 weeks post the operation. Significantly well developed cartilage growth, chondroblasts and chondrocytes invade the area of the operation .High increase in the thickness of connective tissue in the same area contain mainly collagen fibers and lesser amount of elastic fibers. He –Ne laser irradiation raised the mitotic activity of the cartilage cells, activated the reproduction processes in addition to the intra and extra regenerative repai
Preparation and Properties of a Novel Eco-friendly Carboxymethylcellulose /K- Carrageenan /Graphene oxide Gel Beads for the Removal of Heavy Metals from Water
A novel environmentally-friendly adsorbents, carboxymethyl cellulose /k-carrageenan /graphene oxide (CMC/KC/GO) gel beads (GBs) was prepared via a simple method. The composition and morphology of these gel beads were characterized by Fourier transform infrared spectroscopy, thermogravimetric analysis, and scanning electron microscopy. The maximum adsorption capacity of (CMC/KC/GO) GBs for Cu (II) and Co (II) was 2.85 and 1.87 mmol/g respectively at 30oC. Factors affecting the adsorption capacity of metal ions such as CMC/KC ratios, GO ratios, pH, initial metal ions concentration, and the temperature were also explored. The kinetics studies showed that the adsorption process followed the pseudo-second-order kinetics. The analysis of the isotherm indicated that the Langmuir isotherm is in a good agreement with the sorption process. The thermodynamic parameters indicate that the adsorption process was endothermic and spontaneous. The adsorption capacity of the GBs barely declined even after six cycles of regeneration; furthermore, the GBs can be simply separated from the aqueous solution after adsorption by a simple filtration. Keywords:Carboxymethyl cellulose; k-carrageenan ;graphene oxide ; gel beads; isother
Resonance of a rectangular plate influenced by sequential moving masses
In this work, an improved semi-analytical technique is adopted to track the dynamic response of thin rectangular plates excited by sequential traveling masses. This technique exploits a so-called indirect definition of inertial interaction between the moving masses and the plate and leads to a reduction, in the equations of motion, of the number of time-varying coefficients linked to the changing position of the masses. By employing this optimized method, the resonance of the plate can be obtained according to a parametric study of relevant maximum dynamic amplification factor. For the case of evenly spaced, equal masses travelling along a straight line, the resonance velocity of the masses themselves is also approximately predicted via a fast methodology based on the fundamental frequency of the system only
The Fracturing of Pakistan
Pakistan’s democratic and civilian groups face various problems: Issues of national integrity, reduction of violence, the creation of a governing consensus among different provinces and ethnic groups; all of these will have to be tackled by the new parliament. But just as important as the restoration of democracy and the end of military involvement in politics are problems of poverty and economic deprivation
Sulfate-reducing bacteria metabolite detection using GC-MS
This research was conducted to investigate and compare the various metabolite, produced from the metabolism of two different SRB strain, that were involved in the biocorrosion process. Stainless steel coupons were immersed in two strains of sulfatereducing bacteria, A1H1 and EB3 (designated as SRB1 and SRB2 repectively) were isolated from Port Dickson marine vicinity that were grown in VMNI medium. The immersion period were set for eight days. Analysis of Gas Chromatography-Mass Spectrometry (GC-MS) was conducted using –trimethylsilyl (TMS) of N-methyl-N-trimethylsilylfluoracetamide (MSTFA). The data were than analyzed using Partial Least Squares Discriminant Analysis (PLS-DA) method to discriminate the unique metabolite according to each strain. The result showed that SRB1 generates less metabolite but high in concentration.
Meanwhile, SRB2 shows a variety production of metabolites but less in concentration. Both strains share the same metabolism in the production of nitrogen based substance and production of norvaline and pentanoic acid. SRB1 shows a very distinct feature as the production of ribitol was spotted in its metabolism where it is usually associated with growth. SRB2 showed a very close usage of sulphur by production of methionine. These results suggest that different SRB strain produced different number and type of metabolites in the biocorrosion process
Pore Network Modelling of Slender Packed Bed Reactors
Packed bed reactors are common reactor types in chemical industries. In case of reactions with large heat effects, bundles of slender tubes are used. For such slender tubes, the column-to-particle diameter ratio, N, is small, which can give rise to significant flow channelling. This research uses two particle-scale numerical approaches, namely particle-resolved computational fluid dynamics (PR-CFD) and pore network model (PNM), to investigate the hydrodynamics of three packed beds containing random packings of spherical particles with 4.2⩽N⩽ 7.0. Global parameters of the PNM, such as shape and constriction factors, are optimized using the PR-CFD results. A comparison of computed PNM and PR-CFD results shows that the PNM captures local variations in the bed well. The low computational cost of PNM, as well as its ability to provide locally resolved data, makes the PNM a promising approach for the pore-scale modelling of slender packed bed reactors
Awareness on the use of solar tent dryer among the fish processors of Kukawa Local Government, Borno State
This study was carried out in order to assess the use of solar tent dryer in some selected fishing settlement (Yobe, Daban Masara, Tumbun Beriberi and fish Dam) in Kukawa Local Government. Secondary and Primary data were used in this research. Secondary data were obtained from various literatues while primary data were obtained through the use of structured questionnaires. A total number of 60 respondents were randomly selected and interviewed: Fifteen from each settlement (fish processors). Simple percentages were used in analyzing the data. Findings revealed that, majority of the respondents (fish processors) 80% were not aware of the existence of solar tent dryer that can be used for drying fish, only 20% were aware of solar tent dryer.Among these respondents who are aware of solar tent dryer, only 3.33% have used it. The general perceptions of the respondents believe that they will use it if they are provided with the solar tent dryer. The level of awareness on the use of solar tent dryer for fish processing is very low, there is need for intensive awareness creation, through fishery extension workers
Residual stress development in selective laser-melted Ti6Al4V: a parametric thermal modelling approach
High cooling rates within the Selective Laser Melting (SLM) process can generate large residual stresses within fabricated components. Understanding residual stress development in the process and devising methods for in-situ reduction continues to be a challenge for industrial users of this technology. Computationally efficient FEA models representative of the process dynamics (temperature evolution and associated solidification behaviour) are necessary for understanding the effect of SLM process parameters on the underlying phenomenon of residual stress build-up. The objective of this work is to present a new modelling approach to simulate the temperature distribution during SLM of Ti6Al4V, as well as the resulting melt pool size, solidification process, associated cooling rates and temperature gradients leading to the residual stress build-up. This work details an isotropic enhanced thermal conductivity model with the SLM laser modelled as a penetrating volumetric heat source. An enhanced laser penetration approach is used to account for heat transfer in the melt-pool due to Marangoni convection. Results show that the developed model was capable of predicting the temperature distribution in the laser/powder interaction zone, solidification behaviour, the associated cooling rates, melt-pool width (with 11% error) and melt-pool depth (with 3% error) for SLM Ti6Al4V. The model was capable of predicting the differential solidification behaviour responsible for residual stress build-up in SLM components. The model predicted trends in cooling rates and temperature gradients for varying SLM parameters, correlated with experimentally measured residual stress trends. Thus the model was capable of accurately predicting the trends in residual stress for varying SLM parameters. This is the first work based on the enhanced penetrating volumetric heat source, combined with an isotropic enhanced thermal conductivity approach. The developed model was validated by comparing FEA melt-pool dimensions with experimental melt-pool dimensions. Secondly the model was validated by comparing the temperature evolution along the laser scan path with experimentally measured temperatures from published literature
Effect of Aqueous Leaf Extract of Jatropha tanjorensis on parasitaemia and haematological parameters in mice infected with Plasmodium ber ghei
Medicinal plants are proven sources of many useful drugs in our modern world. Jatropha tanjorensis, known as hospital too far, is consumed highly in Africa as herbal medicine. This research work was done to evaluate the effect of aqueous leaf extract of Jatropha tanjorensis on parasitaemia and haematological parameters in mice infected with Plasmodium ber ghei. The leaves of J. tanjorensis were extracted with distilled water and qualitative phytochemical analysis carried out. Acute toxicity studies were carried out using the Organization for Economic Cooperation and Development (OECD) guideline. The curative activity of the extract was examined using Rane’s test. A total of forty (40) mice were used for the study and they were infected with Plasmodium berghei. The infected mice were subdivided into five groups of six mice each and treated with different doses of standard drug (artemether/lumefantrine 25mg/kg) and extract (200, 400 and 800mg/kg body weight) for 4 days. After treatment, blood was collected and used for percentage parasitaemia, packed cell volume and hemoglobin concentration. The result of phytochemical analysis revealed the presence of alkaloids, tannins, saponins, flavonoids, terpe noids, cardiac glycosides and anthra quinones. The result of the acute toxicity showed the signs of neither neurological, behavioral nor mortality at concentrations of 2,000 and 5,000 mg/kg oral doses within the first 24 hours and during the 14 days study period. A dose- dependent increase was observed in Total haemoglobin (Hb) and Packed cell volume (PCV) levels which was collaborated with increase in weight as compared with negative control. The leaf extract of J. tanjorensis also revealed a significant (p<0.05) suppression activity and mean survival time at the doses of 400 mg/kg, 200 mg/kg and 100 mg/kg when compared with the negative control. The extract of Jatropha tanjorensis showed reasonable levels of anti-anaemia and antimalarial activities with no signs of acute toxicity. Therefore this study may support its use as an anti-prophylactic and blood tonic nutraceutical
Improve the Process of Enhancing Oil Recovery (EOR) by Applying Nanomagnetic Cobalt Ferrite Nanoparticles
In this paper we reported nano-crystalline cobalt ferrite powders were synthesized using co-precipitation method at 600 °C, 700 °C and 800 °C. The structural, morphological and magnetic properties of the powders were investigated by x-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, transmission electron microscopy (TEM) and vibrating sample magnetometer (VSM). Infrared spectral analysis data between 200 and 1000 cm-1 defined the intrinsic cation vibrations of the characteristic spinel structure system. The saturation magnetization (Ms) and coercivity (Hc) of the CoFe2O4 were found to be in the range of 94-33 emu/g, which is still in the range of hard ferrite. The observed variation in saturation magnetization, coercivity and remanence magnetization as a function of increasing the temperature and grain size of samples. From this point of view, nano-scale size of nanoparticles makes them efficient for using in borehole stability maintaining for enhancing oil and gas recovery efficiency improvement. The large value of magnetic pressure (-2.95699) are expected to be useful in oil recovery applications. It has also been found that the choice of nanoparticles for application in oil recovery depends on nature, magnetic and electric properties of the reservoir rock
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