The impact of excited neutrinos on ννˉ→γγ\nu \bar{\nu}\to \gamma\gamma process

We examine the effect of excited neutrinos on the annihilation of relic neutrinos with ultra high energy cosmic neutrinos for the $\nu \bar{\nu}\to \gamma\gamma$ process. The contribution of the excited neutrinos to the neutrino-photon decoupling temperature are calculated. We see that photon-neutrino decoupling temperature can be significantly reduced below the obtained value of the Standard Model with the impact of excited neutrinos.Comment: 11 pages, 3 figures, published versio

Cutting performance and wear characteristics of PVD coated and uncoated carbide tools in face milling Inconel 718 aerospace alloy

In this paper, cutting performance and failure characteristics of two PVD TiN coated and an uncoated tungsten carbide grades with identical geometry are presented. Face-milling tests of Inconel 718 superalloy were performed to investigate the effect of cutting speed and feed rate on tools performance under wet conditions. Tools were thoroughly examined under SEM at two stages in order to reveal the failure modes and wear mechanisms. These stages were after cutting for 5 s and when the tool failed. It was noted that the coating resulted in a marginal improvement, as it was delaminated by adhering workpiece material at the beginning of the cut, impeding the performance of the tool for the rest of the experiment. A combination of progressive chipping and flank wear was the general mode of tool failure, former being dominant at high speeds and the latter at the low speed region. Results showed that uncoated tool performed better than coated tools at low cutting speeds while coated tools gave slightly better performance as the speed was raised

Determination of volatile compounds of the first rose oil and the first rose water by HS-SPME/GC/MS techniques

Background: Rose water and rose oil are used in the perfume, cosmetic, pharmaceutical and food industries. The determination of volatile compounds in rose oil and rose water obtained from oil-bearing rose is highly important in terms of availability in the industry and in human health.Materials and Methods: Twenty four and twenty six volatile compounds were determined in the first rose oil and in the first rose water. Thus, in this study, volatile compounds in the first rose oil and first rose water have been determined by HS-SPME/GC/MS (Headspace-Solid Phase Micro Extraction/Gas Chromatography Mass Spectrometry) techniques which were not published previously for determining volatile compounds in rose oil and rose water.Results: Twenty four and twenty six volatile compounds were found in the first rose oil and in the first rose water, respectively. It was further discovered that both first rose oil and first rose water are rich in oxygenated monoterpenes and sesquiterpenes, with a third group of volatile compounds known as aliphatic hydrocarbons being found only in first rose oil. Citronellol contents of the first rose oil and rose water were found to be 43.40% and 40.13% respectively, whereas geraniol contents were 11.81% and 15.97%, respectively.Conclusion: These findings suggest that HS-SPME/GC/MS is a suitable technique for the determination of volatile compounds of rose oil and rose water.Keywords: Oil-bearing rose, Rosa damascena, HS-SPME/GC/MS, volatile compounds

Učinak eksplicitnog uključujućeg refleksivnog poučavanja na znanstvenu pismenost

The purpose of this study was to investigate the effectiveness of explicit-embedded-reflective (EER) instruction in scientific literacy levels of the ninth grade advanced science students by assessing content knowledge and scientific literacy levels. The study was conducted with 51 students by using experimental design. In the treatment group, the EER teaching was performed, while in the comparison group the instruction was conducted by lecturing, demonstration and questioning strategies in a teacher-centred context. Nature of Science Literacy Test and Cell Content Knowledge Test were used for data collection. T-tests were utilized for data analysis. The results of the study showed that the EER teaching was effective in terms of increase in scientific literacy levels and cell content knowledge in the treatment group. In addition, the approach was more effective in increasing scientific literacy levels and cell content knowledge than the regular approach.Svrha ovoga rada bila je istražiti učinkovitost eksplicitno-uključujuće-refleksivne metode poučavanja (dalje u tekstu EER) na znanstvenu pismenost naprednih učenika devetih razreda iz prirodoslovlja procjenjujući poznavanje sadržaja i razinu znanstvene pismenosti. U istraživanju je sudjelovao 51 učenik, a provedeno je uz pomoć eksperimentalnog nacrta. U eksperimentalnoj skupini primijenjeno je poučavanje metodom EER, a u kontrolnoj skupini poučavanje je provedeno u obliku predavanja, demonstracija i strategija ispitivanja u kontekstu koji je orijentiran na nastavnika. Za prikupljanje podataka korišteni su Test znanstvene pismenosti i Test o poznavanju stanice. Za analizu podataka korišteni su T-testovi. Rezultati ovoga istraživanja pokazali su da je primjena EER metode u poučavanju učinkovita s obzirom na povećanje razina znanstvene pismenosti i znanja o stanici u eksperimentalnoj skupini. Nadalje, taj je pristup bio učinkovitiji kod podizanja razine znanstvene pismenosti i znanja o stanici od uobičajene metode poučavanja

How does a biopsy of endoscopically normal terminal ileum contribute to the diagnosis? Which patients should undergo biopsy?

Background: Terminal ileum endoscopy and biopsy are the diagnostic tools of diseases attacking the ileum. However, abnormal histological findings can be found in endoscopically normal terminal ileum.Objective: This study was performed to evaluate the histopathological results of biopsies from endoscopically normal terminal ileum in order to determine pre-procedure clinical and laboratory factors predicting abnormal histopathological results, if any.Methods: A total of 297 patients who underwent colonoscopy and terminal ileum biopsy and had normal terminal ileum or a few aphthous ulcers in the terminal ileum together with completely normal colon mucosa were included in the study. The patients were grouped into two arms as normal cases and cases with aphthous ulcers. Histopathological and pre-procedural laboratory results of patients were analyzed according to their indications.Results: The terminal ileum was endoscopically normal in 200 patients, and 97 patients had aphthous ulcers. Chronic ileitis rate was present in 5.5% of those with endoscopically normal terminal ileum and in 39.2% of the patients with aphthous ulcers. In both groups, the highest rate of chronic ileitis was detected in the patients with known inflammatory bowel disease (IBD) (15.4 and 50%, respectively), anemia (9.5 and 43.5%, respectively), and in the patients having chronic diarrhea together with abdominal pain (7.7 and 44.8%, respectively). We found that the sensitivity of mean platelet volume for predicting chronic ileitis was 87% and the specificity was 45% at a cut-off value lower than 9.35 fl.Conclusion: In anemia indication or chronic diarrhea together with abdominal pain, the frequency of aphthous ulcers detected by ileoscopy and the frequency of chronic ileitis detected histopathologically despite a normal-appearing ileum were elevated.Keywords: Terminal ileum; ileoscopy; chronic ileitis; inflammatory bowel diseas

Probe of extra dimensions in gamma q->gamma q at the LHC

We have examined TeV scale effects of extra spatial dimensions through the processes gamma q-> gamma q where q=u,d,c,s,b, anti-u, anti-d, anti-c, anti-s, anti-b. These processes have been treated in a photon-proton collision via the main reaction pp-> p gamma p-> p gamma qX at the LHC. We have employed equivalent photon approximation for incoming photon beams and performed statistical analysis for various forward detector acceptances.Comment: 17 pages, 5 figure

METU interoperable database system

and Sevgi Foundation, Turkey) is a multidatabase system based on OMG's (OMG is a registered trademark, and CORBA, ORB, OMG IDL, Object Request Broker are trademarks of OMG) distributed object management architecture. It is implemented on top of a CORBA compliant ORB, namely, DEC's ObjectBroker (ObjectBroker is a registered trademark of DEC Corp.) [DDO96]. In MIND all local databases are encapsulated in generic Database Object. The interface of the generic Database Object is de ned in CORBA IDL and multiple implementations of this interface, one for each component DBMSs, namely, Oracle7 (Oracle7 is a trademark of Oracle Corp.), Sybase (Sybase is a trademark of Sybase Corp.), Adabas D (Adabas D is a trademark of Software AG Corp.) and MOOD [Dog94] are provided. MIND provides its users a common data model and a single global query language based on SQL. The main functionalities of MIND are global query processing, global transaction management and schema integration. The basic component classes in the system are