109,813 research outputs found
High-performance SiC-fibre reinforced beta-sialon CMCs prepared from heat-treated Nicalon fibres
No full textIn a previous paper (Demir, A. and Thompson, D. P., Heat-treatment of Nicalon SiC fibres in various atmospheres and pressures. In Proc. 3rd Int. Turkish Ceramic Congress, Vol. 2, Engineering Ceramics, ed. V. Gunay, H. Mandal and S. Ozgen. Turkish Ceramic Society, Istanbul, 1996, pp. 180-185) it was reported that a high-pressure, high-temperature carbon monoxide treatment of Nicalon SiC fibres resulted in significantly improved strength and refractoriness, and at the same time deposited a thin carbon coating on the surface of the fibres. In the present study, fibres heat-treated in this way have been used to reinforce a range of beta -sialon ceramic matrices, and the resulting mechanical properties (bend strength, fracture toughness) have been compared with results for similar materials prepared from non-heat-treated Nicalon fibres. All samples showed significant increases in strength and density, with in general, not much change in fracture toughness. The presence of the coating on the fibres assisted the densification of the composites by decreasing friction during hot-pressing, thereby increasing density and matrix strength. SEM micrographs indicated that the carbon coating is still present after fabrication and is sacrificed during fracture, assisting in easy gull-out of fibres. (C) 2001 Elsevier Science Ltd. All rights reserved
Sense of identity and depression in adolescents
No full textDemir B, Kaynak-Demir H, Sonmez EI. Sense of identity and depression in adolescents. Turk J Pediatr. 2010; 52: 68-72
Sense of identity and depression in adolescents
No full textDemir B, Kaynak-Demir H, Sonmez EI. Sense of identity and depression in adolescents. Turk J Pediatr. 2010; 52: 68-72
Sense of identity and depression in adolescents
No full textDemir B, Kaynak-Demir H, Sonmez EI. Sense of identity and depression in adolescents. Turk J Pediatr. 2010; 52: 68-72
Aydin S, Demir MG, Baran H. Clinical and pathological examination of jaw masses: Retrospective analysis of 69 cases. Mustansiriya Med J 2021;20:12-6
No full textIntroductıon: The aim of this study was to retrospectively evaluate the clinicopathological features of the patients who presented with a mass in the jaw. Materıals and Methods: Clinical files and histopathological records of 69 patients who presented to our clinic with complaints of swelling or mass in the upper or lower jaw between 2010 and 2018 were analyzed retrospectively. Results: Of the cysts and tumoral lesions in patients, 50.7% (35/69) were located in the maxilla and 49.3% (34/69) were located in the mandible. 23 (32.8%) odontogenic cysts, 11 (15,7%) non-odontogenic cysts, 15 (21.4%) odontogenic tumors, 12 (17,4%) local metastases from adjacent tissues to maxilla and mandible, 5 (7.1%) other distant metastases. Among the odontogenic cysts, the most common radicular cysts were 39.13% (10/23), the second had dentigerous cyst 34.78% (8/23). In our 11 patients with non-odontogenic cysts, only nasoalveolar cysts were observed. The distribution of odontogenic tumors are; 40% (6/15) odontoma, 26.6% (4/15) giant cell reparative granuloma, 20% (3/15) ameloblastoma, 6.6% (1/15) rates of cementoma and odontogenic fibroma. Conclusıon: When the etiologic causes of the patients who have complaints of mass in the jaw are examined, we can encounter many different pathologies. Although odontogenic and non-odontogenic cysts are the most common benign masses, we should consider the masses that metastasize to this region and the primary tumors originating from this region
EFFECTS OF SOME RHIZOBACTERIA AND INDOLE-3-BUTYRIC ACID ON ROOTING OF BLACK AND WHITE MULBERRY HARDWOOD CUTTINGS
No full textThis research was conducted to determine the effects of treatments with indole-3-butric acid (0, 2, 4 and 6 g l(-1) IBA) and plant growth promoting rhizobacteria (PGPR) (Burkholderia gladii-BA7, Bacillussubtilus-OSU142 and Bacillusmegatorium-M3) strains have on rooting and root growth of hardwood stem cuttings of black and white mulberry both alone and in combination with each bacterial strain. Cuttings in the control group were treated with 50% ethanol + 50% distilled water. The hardwood stem cuttings (middle parts of one-year-old shoots) for rooting were selected from 15-year-old healthy donor black and white mulberries trees on February 1, 2015 and 2016 in Bolu, Turkey. The treated cuttings were placed in perlite medium in unheated trays of a greenhouse with automated misting system for 90 days. The rooting rate, root number, root length and diameter were evaluated. The rooting rate varied from 12.0 to 85.0%. The number of root varied from 2.05 to 10.19. The root length varied from 2.75 to 8.72 cm. The root diameter varied from 0.81 to 2.49 mm. The results indicated that treatment with 4 g l(-1) IBA plus B. megatorium-M3 solution had a profound effect in increasing rooting capacity and quality in comparison to the control, and all other PGPR and IBA treatments. Overall, rooting rate and root quality of black mulberry hardwood cuttings was found to be lower than those of white mulberry. Moreover, 4 g l(-1) IBA was the most appropriate dose and B. megatorium-M3 bacterial strain was the most appropriate rhizobacteria for rooting of mulberry cuttings
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Parameters affecting diagonal cracking behavior of reinforced concrete deep beam
No full textIn this study, an experimental study is performed to investigate the effects of section height (h), ratio of shear span to effective depth (a/d) and compressive strength of concrete (f(c)(')) parameters on diagonal cracking and crack width behavior of RC deep beams after making comprehensive literature research. Effect of shear reinforcement on this behavior is also investigated. Eleven different RC deep beam specimens with or without shear reinforcement are tested under a 3-point loading with a simple support condition. Firstly, the test results reveal that the load carrying capacity of the specimens increases with an increase in section height. Very minor increments in mid-displacements are determined as well. Small increments are experienced in crack widths as h increases. Secondly, an increase in the shear strength of the tested members is obtained as a/d decreases. A small decrease in displacement values is observed with a brittle behavior as well. Moreover, diagonal crack widths increase along with an increment in a/d ratio. Thirdly, an increment of makes a significant contribution to the shear strength of RC deep beams. However, it results in a decrease in maximum diagonal crack widths. Lastly, shear reinforcement makes a very significant contribution to shear strength due to confining struts
Tam Çiçeklenme Döneminde Yapraktan Uygulanan Kitosan, Demir Oksit ve Kitosanla Kaplanmış Demir Oksit Nanopartiküllerinin Farklı Konsantrasyonlarının Hypericum triquetrifolium Turra.’nın İkincil Metabolitleri Üzerine Etkileri
No full textHypericum triquetrifolium Turra. (Hypericaceae) is one of the
important medicinal plants. This herb is used in Turkish folk
medicine for its antidepressant, anthelmintic and antiseptic effects.
Hypericum extracts have an important commercial value in the
pharmaceutical industry. Therefore, studies to increase the amount
of secondary metabolites it contains are becoming widespread.
Elicitors are biological and non-biological factors that can affect the
synthesis of secondary metabolites in plants. In recent years,
nanoelicitors have been used to increase the amount of active
ingredients. In this study, to stimulate the synthesis of biologically
active secondary compounds of H. triquetrifolium; chitosan, iron
oxide and chitosan-coated iron oxide nanoparticles in concentrations
of 0 (control), 50, 75, 100 and 150 ppm were sprayed on the leaves
during full bloom. LC-MS/MS analysis showed that application of
100 and 150 ppm chitosan nanoparticles increased the amount of
flavonol (hyperocyte and quercitrin) and naphthodianthrons
(pseudohypericin and hypericin) in H. triquetrifolium. 50 ppm iron
oxide nanoparticle hyperocyte, quercitrin and pseudohypericin; 75
and 100 ppm iron oxide nanoparticles increased the amount of
hyperocyte, quercitrin and hyperforin. The 150 ppm iron oxide
nanoparticle resulted in an increase in all compounds except
hypericin. In this study, iron oxide nanoparticles coated with
chitosan were also used as elicitors to improve the chemical and
biological properties of iron oxide. In this series, iron oxide
nanoparticle coated with 100 ppm chitosan was effective and
increased the amounts of quercitrine, kaempferol and
pseudohypericin. The concentration of 75 ppm of this group was
effective on quercitrin.Hypericum triquetrifolium Turra. (Hypericaceae) önemli tıbbi
bitkilerden biridir. Bu bitki Türk halk tıbbında antidepresan,
antelmintik ve antiseptik etkileri nedeniyle kullanılmaktadır.
Hypericum özütleri ilaç endüstrisinde önemli bir ticari değere
sahiptir. Bu nedenle içerdiği ikincil metabolitlerin miktarını
artırmaya yönelik çalışmalar yaygınlaşmaktadır. Elisitörler,
bitkilerde ikincil metabolitlerin sentezini etkileyebilen biyolojik ve
biyolojik olmayan faktörlerdir. Son yıllarda, aktif bileşen miktarını
artırmak için nanoelisitörler kullanılmaktadır. Bu çalışmada, H.
triquetrifolium'un biyolojik aktif sekonder bileşiklerinin sentezini
uyarmak için; tam çiçeklenme döneminde yaprakların üzerine 0 (kontrol), 50, 75, 100 ve 150 ppm konsantrasyonlarında kitosan,
demir oksit ve kitosanla kaplanmış demir oksit nanopartikülleri
püskürtülmüştür. LC-MS/MS analizi, 100 ve 150 ppm’lik kitosan
nanopartikülleri uygulanmasının, H. triquetrifolium'da flavonol
(hiperosit ve kuersitrin) ve naftodiantronların (psödohiperisin ve
hiperisin) miktarını artırdığını göstermiştir. 50 ppm demir oksit
nanopartikülü hiperosit, kuersitrin ve psödohiperisin; 75 ve 100
ppm'lik demir oksit nanopartikülleri ise hiperosit, kuersitrin ve
hiperforin miktarlarını artırmıştır. 150 ppm'lik demir oksit
nanopartikülü, hiperisin dışındaki tüm bileşiklerde artış sağlamıştır.
Bu çalışmada, demir oksidin kimyasal ve biyolojik özelliklerini
iyileştirmek için kitosanla kaplanmış demir oksit nanopartikülleri
de elisitör olarak kullanılmıştır. Bu seride, 100 ppm'lik kitosanla
kaplanmış demir oksit nanopartikülü etkili olmuş ve kuersitrin,
kaempferol ve psödohiperisin miktarlarını arttırmıştır. Bu grubun
75 ppm'lik konsantrasyonu kuersitrin üzerinde etkili olmuştur
Appropriate Similarity Measures for Author Cocitation Analysis
No full textWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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