11 research outputs found
A COMBINED METHOD FOR THE ANALYSIS OF MINE VENTILATION NETWORKS
Havanın serbest olarak dağıldığı havalandırma şebekelerinin çözümü, ocak havalandırmasında temel bir problemdir. Bu problemi çözmek için bir çok sayısal teknik kullanılmaktadır. Bu makalede, hem klasik Hardy Cross Metodu hem de kısıtsız optimizasyon tekniklerinin avantajlarını birleştiren yeni bir metod önerilmektedir. Örnek havalandırma şebekeleri üzerindeki denemeler, bu metodun havalandırma şebeke analizinde bir takım kolaylıklar sağladığını göstermektedir. Solving ventilation networks of natural splitting is a basic problem in mine ventilation. Several mathematical techniques are used to solve this problem. This paper proposes a new method which combines the advantages of both classical Hardy Cross method and unconstrained optimisation techniques. The trials carried out on model networks have shown that the method offers some facilities in the analysis of mine ventilation networks
Decreased ocular pulse amplitude and retinal nerve fibre layer in multiple sclerosis
This study was conducted to assess ocular pulse amplitude and retinal nerve fibre layer in patients with multiple sclerosis and their correlation with disease duration and with severity. Retinal nerve fibre layer thickness was measured by Heidelberg Retinal Tomography II (HRT-II; Heidelberg Engineering, Dossenheim, Germany) and ocular pulse amplitude was measured by dynamic contour tonometry (Ziemer Ophthalmic Systems, Port, Switzerland) in 37 multiple sclerosis patients and 72 age- and gender-matched controls. Ocular pulse amplitude was significantly reduced and retinal nerve fibre layer was significantly thinner in temporal, superotemporal, and nasal sectors in patients with multiple sclerosis regardless of having an optic neuritis attack. The retinal nerve fibre layer was thinner in eyes with a previous optic neuritis attack compared with the eyes without an attack, but the difference was not significant. Ocular pulse amplitude showed a positive correlation with visual evoked potential amplitude and a negative correlation with visual evoked potential latency. Retinal nerve fibre layer thickness showed a significant negative correlation with the disease duration but not with visually evoked potential, disease severity, nor previous optic neuritis. These findings indicate that the process of degeneration starts in the early period of the disease, as our study group is composed of early-middle-stage multiple sclerosis patients, and is independent of relapses. © Informa Healthcare USA, Inc
Markers Of Arrhythmia In Patients With Left Ventricular Outflow Tract Stenosis And Coartation Of Aort
Factor analysis method in geochemical characterization study: Çelebi granitoide and Karamadazı granite
Ana bileşen analiz yöntemlerinden "faktör analizi yöntemi" bu çalışmada Karamadazı ve Çelebi granitoyidlerinden elde edilen jeokimyasal analiz sonuçlarının değerlendirilmesinde kullanılmıştır. Buna göre, Karamadazı Graniti'nin jeokimyasal davranışını kontrol eden faktörler ve olarak, Çelebi Granitoyidi'nin jeokimyasal davranışını kontrol eden faktörler ise ve olarak bulunmuştur. Bu faktörlerin esas alındığı Harker tipi diyagramlarda iki bölgedeki granitoyidlerin de bu çalışmada kısır olarak adlandırılan granitoiydlerden belirgin şekilde ayrıldığı gözlenmiştir. Yozgat batoliti, Terlemez kuvarsmonzoniti, Kerkenez graniti, Ekecikdağ kuvarsmonzoniti ve Ağaçören intrüzif takımı gibi Orta Anadolu Granitoyidleri Çelebi Granitoyidi'ne göre daha yüksek silika değerleriyle ve kısmen yüksek toplam alkali değerleriyle farklılaşmaktadır. Bu granitoiydlerin magmatik farklılaşma gösterdikleri ve üretken plütonlann kısır olanlara göre daha az farklılaşmaya uğradıkları öne sürülmektedir. Çelebi Granitoyidinin apatit ve zirkon açısından kısır granitoyidlere göre daha zengin bileşimde olması Çelebi Granitoyidi'nin kısır granitoyidlere göre daha fazla I-tipi karakterinde olduğunu göstermektedir. Karamadazı Graniti, Yozgat batoliti, Terlemez kuvarsmonzoniti, Ekecikdağ kuvarsmonzoniti ve Ağaçören intrüzif takımı gibi Orta Anadolu Granitoyidleri arasında en düşük ortalama Rb, Ba veTh değerleri ve en yüksek ortalama Sc ve V, ve ortalama Zr, Y ve Ni değerleriyle diğerlerine kıyasla kıtasal kabuktan en az malzeme almış granitoyidler olarak göze çarpar. Faktör analizlerinden elde edilen faktörlere göre, Karamadazı Graniti'nin Terlemez ve Ağaçören granitoyidleriyle benzer özellikler sunduğu, ve diğerlerinden belirgin bir şekilde ayrıldığı gözlenmektedir.The principal component analysis, one of the methods in factor analyses was used to evaluate the geochemical composition of Karamadazi and Çelebi granitoids. Based on this method, the factors controlling the geochemical characteristics of the Karamadazi Granite are and ratios, and for the Çelebi Granitoids the and ratios. These two granitoids are clearly distinguished from the sterile/non-productive Central Anatolian Granitoids (CAG) on Harker diagrams based on these controlling factors, (parameters). CAG plutons such as Yozgat batholith, Terlemez quartzmonzonite, Kerkenez granite, Ekecikdağ quartzmonzonite ve Ağaçören intrusive suite are different from the productive Çelebi Granitoids in their higher silica content and generally higher total alkali values. This study suggests that fertile (iron producing) plutons are less differentiated and have very little contribution from continental crust compared to the sterile (non-productive) plutons. Higher apatite and zircon abundances in the Çelebi Granitoid suggest that the Çelebi Granitoid have more l-type characteristics compared to non-productive plutons of CAG. The Karamadazi Granite is the most striking example for the granitoids in CAG plutons above having the least contribution from the continental crust, evidenced by the lowest mean Rb, Ba, Th, the highest mean Sc, V, and mean Zr, Y, Ni contents. Based on the factor analysis, it is proposed that, the Karamadazi Granite display geochemical characteristics similar to the Terlemez and Ağaçören granitoids of CAG
An approach to geochemical characterization of productive versus barren granitoids in terms of iron in Central Turkey
The granitoids associated with, and without skarn type mineralizations in central Anatolia are termed as productive and barren granitoids, respectively. The study of the relationships between plutonic rocks in the Central Anatolian Crystalline Complex in central Turkey suggests a direct genetic connection between the composition of plutons, and their associated ore deposits. In order to discriminate between productive and barren granitoids, two Fe-skarn granitoids (Celebi and Karamadazi), and a series of barren plutons within central Anatolia were examined. The Karamadazi and Celebi granitoids are geochemically different from other barren plutons in Central Anatolia. The parameters governing the productivity of these granitoids were determined by principal component analysis (factor analysis) method. Based on this method, the factors controlling the geochemical characteristics of the Celebi granitoids are (Al2O3 + MgO + Fe2O3 + P2O5 + TiO2 + CaO)/(SiO2), (K2O + Rb)/(Na2O) and Rb/Sr ratios, and for the Karamadazi granitoid the Fe2O3 + MnO + MgO + P2O5 + Y)/(SiO2 + Rb) (FMMY/S) and (Na2O)/(K2O) ratios. These two granitoids are clearly distinguished from the barren Central Anatolian Granitoids (CAG) on Harker diagrams based on these controlling factors (parameters). Barren CAG plutons are different from the productive Celebi granitoids in their higher silica content and generally higher total alkali values. This study suggests that iron-producing granitoids are less differentiated and receive little contribution from continental crust compared to the barren granitoids. Higher apatite and zircon abundance in the Celebi granitoids suggest that the Celebi granitoids have more I-type characteristics compared to barren plutons of CAG. The Karamad granitoid is the most striking example for the granitoids in CAG, having a higher contribution from the continental crust as evidenced by higher Rb, Ba, Th, the highest mean Sc, V, and mean Zr, Y, Ni contents. Based on the factor analysis, it is proposed that the Karamadazi granitoid displays geochemical characteristics similar to the Terlemez and Agacoren granitoids of CAG. The factor analyses indicated that the first two factors are about the same for both the Fe-producing Celebi and Karamadazi granitoids. Therefore, this similarity has let to a conclusion that the productivity or non-productivity of the granitoids in Central Anatolia can be tested by examining and comparing the distribution of granitoids in diagrams designed according to the factors defined in this study. © 2004 Elsevier Ltd. All rights reserved.National Council for Scientific ResearchThe authors thank to Scientific and Technical Research Council of Turkey that funded this study (TUBITAK, project no: YDABCAG 198Y098). Prof. Dr N. Karahanoglu and an anonymous referee resulted in improvements to this manuscript
EFFECTS OF LOW-LEVEL LASER THERAPY ON GINGIVAL CREVICULAR FLUID ALKALINE PHOSPATASE LEVELS DURING ORTHODONTIC CANINE DISTALIZATION
Epidemiologic and Clinical Features of Open-Globe Injuries in Childhood
Pur po se: To evaluate the epidemiologic and clinical features of open-globe injuries in childhood.
Ma te ri al and Met hod: The records of the pediatric patients who were evaluated for open-globe injuries between 2007 and 2011 in our
department were retrospectively screened. Age, gender, time, setting, localization and cause of injury, follow-up time, complications, number
of surgeries, initial and final visual acuity were assessed.
Re sults: A total of 37 patients were enrolled in the study. Of 37 patients, 12 (32.4%) were girls and 25 (67.6%) were boys with a mean
age of 9.9±4.5. Boy/girl rate was likely to increase as the age increased (p=0.018). Twenty-one (56.8%) patients were injured during play.
The time interval between injury and admission to the hospital was 15.9±29.4 hours. Injuries were most likely to have occurred on the
street (48.6%) and at home (40.5%). Boys were more likely to be injured on the street (68%), whereas girls were more likely to be injured
at home (83.3%) (p=0.001). The most common objects causing injury were sharp metal and wood tools (29.7% - for both genders). Injury
was corneal in 22 (59.5%) patients and scleral in 8 (21.6%) patients. In 18 (48.6%) patients, the injury was complicated, and cataract was
the most common complication. Reoperation was needed in 16 (43.2%) patients. Final visual acuity was equal to or better than 0.5 in 54%
of the patients. Final visual acuity correlated with initial visual acuity (p=0.004, r=0.491).
Dis cus si on: Open-globe injuries in childhood mostly occur at home or on the street via sharp wood or metal objects. Nearly a quarter of
all patients suffer from low vision as a result of these injuries which are mostly preventable. (Turk J Ophthalmol 2012; 42: 16-9
Cretaceous Subduction-Related Magmatism and Associated Porphyry-Type Cu-Mo Prospects in the Eastern Pontides, Turkey: New Constraints from Geochronology and Geochemistry
This study focuses on the Elbeyli-Ordu, Emeksen-Giresun, Güzelyayla-Trabzon and Ulutaş-Ispir porphyry-type prospects located in the Eastern Pontides, Turkey. Our new LA-ICP-MS U-Pb zircon age data reveal that the Elbeyli-Ordu Mo-Cu mineralization is hosted by a 77.0±1.3 Ma-old monzonite/monzodiorite with a shoshonitic character. The Emeksen Mo mineralization, located ~ 40km southeast of the Elbeyli-Ordu prospect, consists of NW- and NE-striking quartz veins crosscuting a high-K calc-alkaline to shoshonitic granite dated at 78.5±0.8 Ma, a granodiorite dated at 78.7±0.5 Ma and porphyry granite dated at 77.7±0.5 Ma. The Güzelyayla porphyry Cu-Mo prospect consists of a stockwork-type Cu-Mo mineralization crosscutting a calc-alkaline 81.4±1.1 Ma-old dacite porphyry and Late Cretaceous calc-alkaline andesite. The Ispir-Ulutaş mineralization is hosted within a highly sericitized 131.1±0.9 Ma-old quartz-porphyry that intruded into a 132.9±0.6 Ma-old calc-alkaline granite porphyry. Our new U-Pb zircon ages, lithogeochemical and radiogenic isotopic data of the host rocks associated with the porphyry-type prospects in the Eastern Pontides indicate that they formed in an arc-related environment during Cretaceous subduction of the Neotethys Ocean, and the Ispir-Ulutaş prospect is attributed to the main stage of the northward subduction of the Neotethys during the Early Cretaceous. We conclude that the Güzelyayla and Emeksen hydrothermal systems were formed during a transitional compressional to extensional tectonic evolution, whereas the Late Cretaceous Elbeyli hydrothermal system was emplaced during an extensional arc magmatic event. Highly-oxidized, high-K calc-alkaline to shoshonitic magmas at Emeksen and Elbeyli were derived from a metasomatised, heterogeneous and enriched lithospheric mantle, with variable degrees of partial melting of the mantle wedge and variable crustal contamination. Mixing/mingling processes between mafic magmas derived from the lower crust and acidic magmas at upper crustal levels played an important role in the formation of Cu-Mo porphyry-type mineralization in the Eastern Pontides