The present study intends to prepare nanofibers mat of polyacrylonitrile by electrospinning technique and investigates their adsorption capacity to Congo red dye from the aqueous solution, after characterize it by different techniques such as FTIR, SEM, EDA, XRD and BET. The influence factors on adsorption were studied including adsorbent dosage, initial concentration, contact time, pH and ionic strength. The results confirmed that the increasing in pH decreases the adsorption capacity. So, the optimum adsorbent dosage, initial concentration and contact time were 0.006 g, 25 mg/L and 150 min respectively. The isotherm models of Freundlich and Langmuir were applied on the experimental adsorption data to evaluate the maximum capacity and energy of adsorption. The experimental data was founded more fitted with Langmuir model. Additional, the thermodynamic parameter changes such ∆G, ∆H and ∆S of adsorption were estimated. The results explained that the adsorption process was exothermic and nonspontaneous.
Background Alloys with the addition of zirconium and niobium eliminate the adverse effects of aluminum and vanadium on the nervous system, the possibility of metallosis and the initiation of diseases (including cancers or Alzheimer›s disease). In addition, they have better corrosion resistance, and a Young›s modulus value similar to longitudinal bone tissue. Therefore, only choosing appropriate materials does not guarantee proper functioning of the implants, the surfaces of the implants also have to be suitable to meet the requirements. The laser surface hardening process modifies the surface properties by imparting microstructural changes, whereas surface remelting induces changes in the surface topography, roughness, wettability and w
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Article information: COVID-19 has roused the scientic community, prompting calls for immediate solutions to avoid the infection or at least reduce the virus's spread. Despite the availability of several licensed vaccinations to boost human immunity against the disease, various mutated strains of the virus continue to emerge, posing a danger to the vaccine's ecacy against new mutations. As a result, the importance of the early detection of COVID-19 infection becomes evident. Cough is a prevalent symptom in all COVID-19 mutations. Unfortunately, coughing can be a symptom of various of diseases, including pneumonia and inuenza. Thus, identifying the coughing behavior might help clinicians diagnose the COVID-19 infection earlier and distinguish
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Background : In order for a tooth to erupt, two obvious requirements are needed. First, there has to be alveolar bone resorption of the bone overlying the crown of the tooth such that an eruption pathway is formed. Second, resorption of bony crypt and apposition of new one, third, there has to be a biological process that will result in the tooth moving through this eruption pathway.The amniotic sac contains a considerable quantity of stem cells. These amniotic stem cells are multipotent and able to differentiate into various tissues, which may be useful for human application. Receptor activator of nuclear factor kappa B ligand (RANKL) is concentrated on bone biology, more specifically bone metabolism. RANKL plays a vital role in osteoclast
... Show MoreDoxycycline and levofloxacin are heterocyclic organic compounds that are now popularly used to treat some bacterial infections. In this study which was conducted on patients from a private clinic, we compared the use of two commonly used antibiotics for the treatment of diagnosed cases with vaginal chlamydial infection: levofloxacin and doxycycline. Vaginal chlamydial infection is considered to be a very common sexually transmitted infection. It may have minimal symptoms which can lead to neglect by the patient until it leads to some important complications among which is the inability to become pregnant. This indicates early diagnosis and treatment of this infection. By comparing the results of treatment we concluded that there is no much
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The present study was conducted to investigate the antimicrobial activity of the hot water and the hot ethanolic extracts of Thuja orientalis against some pathogenic microorganisms (Staphylococcus aureus, Pseudomonas aeruginosa, Eschericha coli, Proteus mirrablis, Salmonilla typhi, Klebsiella pneumoniae, Bacillus cereus, Bacillus subtilus, Acinobacter, Staphylococcus epidermidis and Candida albicans). Results showed that both the water and alcoholic extracts of this plant exert marked inhibitory effect against all the bacterial isolates and yeast and at different ratio, and it was shown that ethanolic extract was more effective in microbial inhibition than the water extract. Maximum inhibition (16 mm) was recorded against Staphylococcus aur
... Show Morein this paper sufficient conditions of oscillation of all of nonlinear second order neutral differential eqiation and sifficient conditions for nonoscillatory soloitions to onverage to zero are obtained
The extraction of iron from aqueous chloride media in presence of aluminum was studied at different kinds of extractants(cyclohexanone, tributyl phosphate, diethyl ketone), different values of normality (pH of the feed solution), agitation time, agitation speed, operating temperature, phase ratio (O/A), iron concentration in the feed, and extractant concentration]. The stripping of iron from organic solutions was also studied at different values of normality (pH of the strip solution) and phase ratio (A/O). Atomic absorption spectrophotometer was used to measure the concentration of iron and aluminum in the aqueous phase throughout the experiments.The best values of extraction coefficient and stripping coefficient are obtained under the
... Show MoreEndoglucanase produced from Aspergillus flavus was purified by several steps including precipitation with 25 % ammonium sulphate followed by Ion –exchange chromatography, the obtained specific activity was 377.35 U/ mg protein, with a yield of 51.32 % .This step was followed by gel filtration chromatography (Sepharose -6B), when a value of specific activity was 400 U/ mg protein, with a yield of 48 %. Certain properties of this purified enzyme were investigated, the optimum pH of activity was 7 and the pH of its stability was 4.5, while the temperature stability was 40 °C for 60 min. The enzyme retained 100% of its original activity after incubation at 40 °C for 60 min; the optimum temperature for enzyme activity was 40 °C.