Modeling of temperature distribution in orthogonal cutting with dual-zone contact at rake face

In this study, an analytical model is developed in order to calculate the temperature distribution in orthogonal cutting with dual-zone contact at the rake face. The study focuses on heat generation at the primary shear zone and at the rake face. The material behavior at the primary shear zone is represented by Johnson-Cook constitutive equation whereas the contact at the rake face is modeled by sticking and sliding friction zones. This new temperature distribution model allows obtaining the maximum temperature at the rake face and helps determining two dimensional temperature distribution in the chip. The simulation results obtained from the developed model are also compared with experimental results where good agreement is observed

Uterin Serviksin Minimal Deviasyon Adenokarsinomu MDA

Minimal deviasyon adenokarsinom MDA servikal adenokarsinomların %1-3 oranında görülen bir varyantıdır.Nadir görülmesi nedeniyle standart tanısal metot ve tedavi protokolü yoktur. Uterin servikste 10-12 cm boyutunda kitlesi olan vakamızda tanı servikal biyopsi ile konamadı.Manyetik rezonans görüntülemede MRI MDA tanısı düşünüldü ve operasyon sonrası tanı kondu. Postoperatif olarak adjuvant kemoradyoterapi KRT uygulandı ve hasta 16 aylık bir süre rekürrens olmadan izlend

Evaluation of patients with fibrotic interstitial lung disease: Preliminary results from the Turk-UIP study

OBJECTIVE: Differential diagnosis of idiopathic pulmonary fibrosis (IPF) is important among fibrotic interstitial lung diseases (ILD). This study aimed to evaluate the rate of IPF in patients with fibrotic ILD and to determine the clinical-laboratory features of patients with and without IPF that would provide the differential diagnosis of IPF. MATERIAL AND METHODS: The study included the patients with the usual interstitial pneumonia (UIP) pattern or possible UIP pattern on thorax high-resolution computed tomography, and/or UIP pattern, probable UIP or possible UIP pattern at lung biopsy according to the 2011 ATS/ERSARS/ALAT guidelines. Demographics and clinical and radiological data of the patients were recorded. All data recorded by researchers was evaluated by radiology and the clinical decision board. RESULTS: A total of 336 patients (253 men, 83 women, age 65.8 +/- 9.0 years) were evaluated. Of the patients with sufficient data for diag-nosis (n=300), the diagnosis was IPF in 121 (40.3%), unclassified idiopathic interstitial pneumonia in 50 (16.7%), combined pulmonary fibrosis and emphysema (CPFE) in 40 (13.3%), and lung involvement of connective tissue disease (CTD) in 16 (5.3%). When 29 patients with definite IPF features were added to the patients with CPFE, the total number of IPF patients reached 150 (50%). Rate of male sex (p<0.001), smoking history (p<0.001), and the presence of clubbing (p=0.001) were significantly high in patients with IPE None of the women <50 years and none of the men <50 years of age without a smoking history were diagnosed with IPE Presence of at least 1 of the symptoms suggestive of CTD, erythrocyte sedimentation rate (ESR), and antinuclear antibody (FANA) positivity rates were significantly higher in the non-IPF group (p<0.001, p=0.029, p=0.009, respectively). CONCLUSION: The rate of IPF among patients with fibrotic ILD was 50%. In the differential diagnosis of IPF, sex, smoking habits, and the presence of clubbing are important. The presence of symptoms related to CTD, ESR elevation, and EANA positivity reduce the likelihood of IPF

Skin prick test results to food allergens in patients with allergic rhinitis

Aim: The role of food allergy in etiology of allergic rhinitis (AR) has not been well established. Allergic rhinitis may be a componentof other atopic disorders. So it is difficult to assess the true prevalence of food induced allergic rhinitis. The aim of this study is toevaluate the skin prick test (SPT) results for some food allergens in allergic rhinitis patients.Material and Methods: A total of 31 items SPT results of 110 patients diagnosed with allergic rhinitis including food allergens andinhalant allergens were evaluated retrospectively. Chi-square test was used for statistical analysis. P value < 0.05 was consideredas statistically significant.Results: Out of all patients 76.4% had positive reaction to at least one allergen while 23.6% had negative SPT to all allergens. Sixtypoint nine % of patients had positive result for at least one food allergen and 67.5% for at least one inhalant allergen. Nine pointone % of patients had positive test results for only food allergens. The most common positively detected food allergens were flours(rye, barley, oat flour) and peanut. Positive test results for cow’s milk was higher in patients under 18 years of age. Also positive testresults to egg and cow’s milk were statistically significantly higher in patients with atopic status than non - atopic.Conclusion: According to our study findings, allergic rhinitis patients may have uncertain sensitivity to cereal flours. It seems that;independently from allergic rhinitis, atopic status is the main condition in patients with cow’s milk and egg allergies

Investigation of temperature distribution in orthogonal cutting through dual-zone contact model on the rake face

A two-dimensional analytical model to calculate the temperature distribution in orthogonal cutting with dual-zone contact on the rake face is presented. The study considers heat generation in the primary shear zone and on the rake face. The material behavior in the primary shear zone is represented by Johnson-Cook constitutive equation while the contact on the rake face is modeled by sticking and sliding friction zones. This new temperature distribution model is used to determine the maximum temperature on the rake face and two-dimensional temperature distribution in the chip and on the tool surface. The dual-zone contact model on the rake face and convection boundary condition on the flank face are the important contributions of this work. The simulation results of the developed model are compared with experimental results where a good agreement is demonstrated

Kütüphanelerde İç Hava Kalitesinin İncelenmesi: Marmara Üniversitesi Merkez Kütüphanesi

Bu çalışmada Marmara Üniversitesi Merkez Kütüphanesi’nde iç ortam hava kalitesi incelenmiştir. İç ortam hava kalitesinin yetersizliği bireylerin çalışma verimlerini düşürebildiği gibi çeşitli sağlık sorunlarına da sebep olabilmektedir. İç ortam hava kalitesini etkileyen önemli kirletici kaynaklarından bir tanesi de partikül maddelerdir. İç hava ortamında bulunan partikül madde (PM), boyutlarına göre (PM10, PM2.5, PM1) insan sağlığını etkileyen hava kirleticilerden biridir. İç ortam hava kirleticileri oranı binaya, yaşanılan bölgeye ve mevsimsel dönemlere göre değişim göstermektedir. Partikül maddeye uzun süre maruz kalındığında göz, burun ve boğaz tahrişi, kaşınma, alerji, kanser, solunum yolu hastalıkları, kalp problemleri gibi çeşitli sağlık sorunlarının oluşumuna yol açabilmektedir. Çalışmamızda kütüphane binasının iç hava ortamında bulunan havadaki 10 mikrondan küçük çaptaki partiküllerin (PM10) kütüphane çalışanları ve kullanıcılarının sağlığına etkisi belirlenmiştir. 05/01/2014-01/06/2014 tarihleri arasında PM10 konsantrasyonu ve kullanıcı sayısı verileri toplanmıştır. PM10 için 2014 kış aritmetik ortalaması 23 μg/m3 ve maksimum değer 130 μg/m3 iken, ilkbaharda aritmetik ortalama 19 μg/m3 ve maksimum değer 127 μg/m3’tür. 05/01/2014-01/06/2014 tarihleri arasında kütüphaneye giren kişi sayısı 09:00-18:59 saatleri arasında ortalama 228 ve maksimum 546’dır. 19:00-08:59 saatleri arasında ise aritmetik ortalama 94 ve maksimum 312 kişi olmuştur. Toz konsantrasyonu ve kullanıcı sayıları karşılaştırıldığında ikisinde de sınav dönemlerinde toz artışı gözlenmiştir. Hem gündüz, hem de gece için PM10 konsantrasyonları ile kişi sayısı arasında korelasyonun yüksek olduğu gözlenmiştir. Dolayısıyla kütüphanedeki kişi sayısı arttıkça havadaki toz miktarı da artmaktadır. Hava Kalitesi Değerlendirme ve Yönetimi Yönetmeliği’nin (2015), Avrupa Birliği (AB) ve Dünya Sağlık Örgütü’nün belirlediği PM10 sınır değerlerinin sınav dönemlerinde aşıldığı gözlemlenmiştir. Kadıköy bölgesindeki dış ortam PM10 konsantrasyonları ile kütüphanedeki PM10 konsantrasyonlarının artış ve azalışlarının benzer olduğu görülmüştür. Kütüphane binasında yeterli havalandırma sistemlerinin bulunmaması nedeniyle iç hava ortamındaki toz partikülleri çalışan ve kullanıcı sağlığı açısından risk oluşturduğu sonucuna ulaşılmıştır. / This study investigated the indoor air quality of the Marmara University Central Library. The inadequacy of the quality of air in an indoor working environment can not only cause individuals to suffer a loss of productivity, but it can also lead to various health problems. Particular matter is one of the important pollutants that affect indoor air quality. Particulate matter (PM) in indoor environments, depending upon the size of the particles (PM10, PM2.5, PM1), is one of the air pollutants that have an impact on human health. The percentage of indoor air pollutants varies according to the particular building in which they are contained, the regional location of the building and the cycle of the seasons. Prolonged exposure to particulate matter may lead to various health problems such as eye, nose and throat irritations, itching, allergies, cancer, respiratory disease, and heart conditions. In our study, we determined the effect of indoor air particles of a diameter of less than 10 microns (PM10) inside the library building on library employees and users. Data on PM10 concentrations and library users were collected over the period January 5, 2014 - June1, 2014. While the 2014 winter arithmetic mean for PM10 was 23 μg/m3 with a maximum value of 130 μg/m3 , in the spring, the arithmetic mean was 19 μg/m3 with a maximum value of 127 μg/m3. Over the period January 5, 2014 - June 1, 2014, the mean number of people entering the library between the hours of 09:00 a.m. - 06:59 p.m. was 228, at a maximum of 546. The arithmetic mean was 94 and the maximum was 312 between the hours of 07:00 p.m - 08:59 a.m. A comparison of the dust concentration and the number of users showed that there was an increase of dust in both factors during exams. A high correlation was observed between PM10 concentrations and the number of users both in the day and at night and therefore it was determined that the higher the number of people occupying the library, the higher was the level of dust in the air. It was seen that the limit value for PM10 set down by Air Quality Assessment and Management Regulations (2015), the European Union (EU) and the World Health Organization (WHO) was surpassed during exam periods. It was observed that the increases and decreases in PM10 concentrations in the outdoor environment in the district of Kadıköy were similar to the PM10 concentrations in the library. The dust particles existing in the indoor air environment of the library building, an outcome of the lack of adequate ventilation systems, presents a health risk for employees and users

Improvement of microstructure of cementitious composites by microbially-induced calcite precipitation

In this study, microstructural improvement of cementitious composites was achieved by bacterial CaCO3 precipitation using three bacterial species, namely Sporosarcina pasteurii, Bacillus cereus, and Actinobacteria sp. M135-3, respectively. The final product was comparatively investigated regarding the physical effects of urease activity of different cells on the mortar in the long term.Microstructural improvement was determined by evaluating the pore structure by determining the increase in strength, decrease in water absorption, and capillary water absorption rate of the cement mortars having different microorganism concentrations (10(6)-10(9) bacteria/ml). These measurements were taken on bacteria-containing and control samples on the 2nd, 7th, 28th, and 56th days, respectively. In addition, calcite and vaterite as calcium carbonate polymorphs formed by the precipitation of calcium carbonate by three types of bacteria were identified by Scanning electron microscopy and energy dispersive X-ray spectroscopy (SEM/EDS), X-ray diffraction (XRD) and Thermogravimetric analysis - Differential scanning calorimetry (TGA-DSC) analyzes.The bacteria-containing mortar samples showed that bacterial species and concentrations directly affect cementitious composites' mechanical and physical properties. Composite samples containing bacteria resulted in statistically significant microstructural improvements measured by higher mechanical strength, lower water absorption value, and capillary water absorption rate compared to control samples, especially at early ages. However, the effect of microbial calcite formation diminishes at later ages, especially at 56-days, attributed to the bacteria cells losing their vitality and integrity and forming spaces inside the mortars.This study was performed as a part of TUBITAK Project no 117M837. The authors would like to acknowledge The Scientific and Technological Research Council of Turkey (TUBITAK) for funding and support in this research project.TUBITAK [117M837]; Scientific and Technological Research Council of Turkey (TUBITAK