gazi university journal of science 

About: gazi university journal of science is an academic journal. The journal publishes majorly in the area(s): Metric space & Estimator. It has an ISSN identifier of 1303-9709. Over the lifetime, 1411 publications have been published receiving 5259 citations.

Antagonistic Effects of Some Lactobacilli On Some Gram-Negative Bacteria

Abstract: Three lactobacilli strains were examined for the inhibitory activity against some gram-negative bacteria with a comparison of well diffusion and spot on lawn method. The inhibitory activity of lactobacilli under spot on lawn method showed significant clear zones. Although in spot on lawn method, lactobacilli have strongest antagonistic activity against P. aeruginosa ATCC 27853, in well diffusion method, it was the least sensitive tested bacteria. In spite of E. coli O157:H7 is inhibited secondly in well diffusion method (16mm), the value of the inhibition is lower than spot on lawn method (26mm). These results showed that spot on lawn method is better method than well diffusion method. Key Words: Antagonism, Gram-negative bacteria, Lactic acid bacteria, Spot on lawn method, Well diffusion method

Scalable and secure sharing of personal health records in cloud computing

Abstract: Personal Health Record (PHR) is an electronic application used by the patients to maintain and manage their health information in a private, secure and confidential environment. In cloud computing, cloud providers act as a third party for information exchange of personal health records. Though this technology facilitates for efficient management and sharing of patient's personal health record, there are wide privacy concerns such as exposure and accessibility of sensitive health information to unauthorized users. In order to provide security and privacy it is necessary to encrypt the data before outsourcing and only authorized users with valid attributes must be allowed to access the data. Hiding the users’ information is also important while accessing data over the network. More over to reduce the key management complexity of data owners, personal health records are classified into multiple security domains. To hide the user information, anonymous authentication through Attribute-Based Encryption (ABE) technique and fine-grained data access control through AES, are adopted. This combination provides a high degree of privacy and security for the PHR file. This scheme enables dynamic modification of access policies or file attributes and on-demand user revocation. Extensive experimental and performance analysis show that the proposed scheme is efficient in terms of security and privacy.

Effect of Cold on Protein, Proline, Phenolic Compounds and Chlorophyll Content of Two Pepper (Capsicum annuum L.) Varieties

Abstract: In this study, quantitative changes of total soluble protein in leaf and stem, apoplastic protein, total phenolic compounds, proline and chlorophyll content were determined in a the cold-susceptible KM-121 (Kahramanmaras- hot) and cold-resistant hybrid pepper Mert ( Capsicum annuum L. ). The plants were raised in a growth room under a controlled environment of 25 ± 2 o C and 16 h light / 8 h dark photoperiod. Then, plants exposed to 4 o C cold stress for three days and control groups were kept at 25 o C. Our results show that cold treatment increased accumulation of apoplastic and total soluble protein, proline, phenolic compounds in pepper seedlings, while decreased the content of chlorophyll. Key Words: Capsicum annuum, Cold Stres, Protein, Phenolic, Proline.

Effect of Minimum Quantity Lubrication (MQL) on Tool Wear, Surface Roughness and Dimensional Deviation in Turning AISI-4340 Steel

Abstract: Normal 0 21 false false false TR X-NONE X-NONE MicrosoftInternetExplorer4 In all machining processes, tool wear is a natural phenomenon and it leads to tool failure. The growing demands for high productivity of machining need use of high cutting velocity and feed rate. Such machining inherently produces high cutting temperature, which not only reduces tool life but also impairs the product quality. Metal cutting fluids changes the performance of machining operations because of their lubrication, cooling, and chip flushing functions but the use of cutting fluid has become more problematic in terms of both employee health and environmental pollution. The use of cutting fluid generally causes economy of tools and it becomes easier to keep tight tolerances and to maintain workpiece surface properties without damages. Due to these problems, some alternatives has been sought to minimize or even avoid the use of cutting fluid in machining operations. Some of these alternatives are dry machining and machining with minimum quantity lubrication (MQL). This paper deals with the experimental investigation on the role of MQL on cutting temperature, tool wear, surface roughness and dimensional deviation in turning of AISI-4340 steel at industrial speed-feed combinations by uncoated carbide insert. The encouraging results include significant reduction in tool wear rate, dimensional inaccuracy and surface roughness by MQL mainly through reduction in the cutting zone temperature and favorable change in the chip-tool and work-tool interaction. Key Words : MQL, tool wear, surface roughness and dimensional deviation

Antimicrobial Activity of some Edible Mushrooms in the Eastern and Southeast Anatolia Region of Turkey

Abstract: In this study, the antimicrobial activity of Pleurotus eryngii var. eryngii, P. eryngii var. ferulae, P. ostreatus, P. sajor-caju, Terfezia boudieri and Agaricus bisporus were investigated. The antimicrobial activity from the methyl alcohol extract of Pleurotus spp., T. boudieri and A. bisporus were evaluated according to the disk diffusion method by using Bacillus megaterium, Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Candida albicans, C. glabrata, Trichophyton spp. and Epidermophyton spp. At the end of the experimental studies, the methyl alcohol extracts of Pleurotus spp., T. boudieri and A. bisporus were shown to inhibit to different degrees the growth of microorganisms to (7.5-15.5 mm) also, mushrooms extract have a lower antimicrobial activity as to a comparison antibiotic (13.0-18.0 mm). Key Words : A. bisporus, Antimicrobial Activity, Pathogen Microorganism, Pleurotus spp., T. boudieri.