The rheological and fusion behavior of polyvinyl chloride (PVC) compounds plays a dominant role in
the processing operations and in the development of physical properties in the processed material. A
comprehensive study was made in this work to evaluate the effect of shear and thermal history on stability, mechanical and rheological properties of rigid PVC compounds. Different samples of Rigid Poly vinyl chloride including dry blend powder, granules, and bottles molded from both were examined. A study was also made on recycled RPVC where 25% of reclaimed material was continuously blended with fresh dry blend and processed for 15 cycles. Results showed that compaction of the PVC material took place in the brabender plastograph at constant temperature and shear stress. Correlations were given to explain results concerning residual stability and rheological behavior. Furthermore, it was seen that elongation and tensile impact are dependent on shear history.
Background: The repair of bone defects remains a major clinical orthopaedic challenge. Bone is a highly vascularised tissue reliant on the close spatial and temporal connection between blood vessels and bone cells to maintain skeletal integrity. Angiogenesis thus plays a pivotal role in skeletal development and bone fracture repair. The role of angiogenic and osteogenic factors in the adaptive response and interaction of osteoblasts and endothelial cells during the multi step process of bone development and repair will be highlighted in this study. This study aimed to identify the role of local exogenous vascular endothelial growth factor in bone healing and to analyze the expression of VEGF by immunohistochemistry in created bone defect af
... Show MoreThe present study was conducted to determined the action of several levels of cytokinis (N6-benzyladenine (BA), 6-furfurylaminopurine (kinetin), N6-(∆-isopentyladenine) (2,ip) on buds proliferation of Phoenix dactylifera L..3 ml explants of the heart of 3 years old offshoot were cultured on Murashige and Skoog medium (1962) containing 3 mg/L activated charcoal, 10 mg/L Naphthalene acetic acid proposed by (1) as a control. Other explants were cultured on this medium supplemented with 0.1, 0.5, 1 mg/L BA. 0.1, 0.5, 1, 2, 3, 4 mg/L Kinetin. 0.1, 0.5, 1 mg/L 2,ip. Best number of buds proliferated has occurred on control medium containing 3 mg/L. 2ip.
Most approaches to combat antibiotic resistant bacteria concentrate on discovering new antibiotics or modifying existing ones. However, one of the most promising alternatives is the use of bacteriophages. This study was focused on the isolation of bacteriophages that are specific to some of commonly human pathogens namely E. coli, Streptococcus pyogenes, Staphylococcus aureus, Proteus mirabilis, Pseudomonas aeruginosa, Salmonella spp. and Klebsiella pneumoniae. These bacteriophages were isolated from sewages that were collected from four different locations in Kirkuk City. Apart from S. pyogenes, bacteriophages specific to all tested bacteria were successfully isolated and tested for their effectiveness by spot test. The most effective
... Show MoreThis study was done to determine the effect of watery and alcoholic extracts of Elettaria cardamomum on growth of bacteria isolated from Otitis media Infections which are : Pseudomonas aeruginosa , Staphylococcus aureus and Klebsilla spp. The biochemical analysis revealed that watery extracts of Elettaria cardamomum contains: Glycosides, Alkaloids, Saponines, Tannins, and Volatile oils, ( This compound is Soluble in water ) , while the alcoholic extracts contains : (in addition to the above mentioned compounds ) Phenols , Resins , Flavonids and Coumarins. ( This compound is Soluble in organic solutions ). To study the e
... Show MoreCdO:NiO/Si solar cell film was fabricated via deposition of CdO:NiO in different concentrations 1%, 3%, and 5% for NiO thin films in R.T and 723K, on n-type silicon substrate with approximately 200 nm thickness using pulse laser deposition. CdO:NiO/n-Si solar cell photovoltaic properties were examined under 60 mW/cm2 intensity illumination. The highest efficiency of the solar cell is 2.4% when the NiO concentration is 0.05 at 723K.
Ferrite with general formula Ni1-x Cox Fe2O4(where x=0.0.1,0.3,0.5,0.7, and 0.9), were prepared by standard ceramic technique. The main cubic spinel structure phase for all samples was confirmed by x-ray diffraction patterns. The lattice parameter results were (8.256-8.299 °A). Generally, x -ray density increased with the addition of Cobalt and showed value between (5.452-5.538gm/cm3). Atomic Force Microscopy (AFM) showed that the average grain size and surface roughness was decreasing with the increasing cobalt concentration. Scanning Electron Microscopy images show that grains had an irregular distribution and irregular shape. The A.C conductivity was found to increase with the frequency and the addition of Cobal
... Show MoreSteel fiber aluminum matrix composites were prepared by atomization technique. Different air atomization conditions were considered; which were atomization pressure and distance between sample and nozzle. Tensile stress properties were studied. XRF and XRD techniques were used to study the primary compositions and the structure of the raw materials and the atomized products. The tensile results showed that the best reported tensile strength observed for an atomization pressure equal to 4 mbar and sample to nozzle distance equal to 12 cm. Young modulus results showed that the best result occurred with an air atomization pressure equal to 8 mbar and sample to nozzle distance equal to 16cm
Women are considered the real power to build societies, as they are half of society, and it is their responsibility to raise generations، as human history testifies to the recording of great names with their giving and achievement in various scientific, social and humanitarian disciplines. Because of the importance of women in our lives, society must give them special care, whether at home or within the community structure to which they belong, so that they contribute to the image that brings about a transformation in the public scene, as well as providing them with support to take charge of bringing about change themselves, and this explains the interest of the press at all levels. Women's issues and topics through various journal
... Show MorePseudomonas aeruginosa readily binds to different kind of abiotic surfaces and form biofilm. The ability of the bacterial species to form biofilm onto polyvinyl chloride (PVC) is associated with several economic, health and environmental problems. The effect of kind of water on ability of this bacterium to form biofilm is scanty in literature. In present study, the ability of different environmental isolates of P. aeruginosa to form biofilm onto polystyrene microtiter plate was evaluated. Furthermore, the effect of waters that collected from different sources on biofilm formation of this bacterium onto PVC was studied. Spectrophotometric method was used to check the ability of bacteria to form biofilm and evaluated the role of waters onto a
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