Thermal properties of nanoparticle colemanite mineral and its advantages in application

Kolemanit minerali (C-3 mm) ve öğütülmüş kolemanit mineralleri (C-75 µm ile C-45 µm tozları) Eti Maden Bigadiç Bor İşletme Müdürlüğünden tedarik edildi. C-3 mm başlangıç malzemesi yüksek enerjili bilyalı değirmende öğütme işlemine tabi tutuldu. Akabinde bu malzeme mikronaltı boyutlu/nano boyutlu partiküller üretebilmek amacıyla ASTM standardındaki boyutu 25 μm olan bir elekten geçirildi (C-25 μm). C-3 mm mineralinin, C-75 µm tozunun, C-45 µm tozunun ve C-25 μm tozunun ısıl özellikleri TermoGravimetri (TG)/Diferansiyel Termal Analiz (DTA) cihazı ile belirlendi. DTA ölçümünde, ilk ayrışma sıcaklığı C-3 mm minerali için 406°C’de yüksek şiddete sahip endotermik bir pik ile gözükürken, C-25 μm tozu için 388°C’de endotermik bir pik ile ortaya çıktı. Diferansiyel TG ölçümünde, ilk ayrışma sıcaklığı C-3 mm minerali için 403°C’de yüksek şiddete sahip dar endotermik bir pik ile belirdi ve C-25 μm tozu için de 388°C’de endotermik bir pik ile ortaya çıktı. Önceki bir çalışmada, C-75 µm, C-45 µm ile C-25 μm tozları Portland çimentolu betona farklı oranlarda ilave edilmiştir. Çalışma sonunda betonun basınç dayanımında belirgin bir artış gözlemlendiği rapor edilmiştir. Bu bulguların nano boyutlu bor mineralleri ile alakalı mühendislik araştırmalarına ışık tutacağı düşünülmektedir

Investigation of nano ulexite mineral effects on mechanical behaviour of warm mix asphalt pavements

U radu je prikazano istraživanje pokazalo je da su potrebna daljnja ispitivanja aditiva u tehnologiji proizvodnje toplih asfaltnih mješavina. Uočeno je da se negativni učinak gubitka adhezije u asfaltnim mješavinama proizvedenim toplim postupkom može smanjiti dodatkom nanočestica minerala uleksita komercijalnom aditivu. U tu su svrhu provedena ispitivanja stabilnosti po Marshallu, indirektno ispitivanje modula vlačne čvrstoće i ispitivanja osjetljivosti na vlagu. Na temelju analize dobivenih rezultata vidljivo je da se temperatura proizvodnje WMA mješavine može dodatno smanjiti, a prilikom ugradnje takvih mješavina potrebna je manja energija zbijanja, čime se osigurava ušteda energije.The research presented in the paper shows that further investigations on additives used in the warm mix asphalt technology are needed. It was observed that the negative effect of adhesion loss in asphalt mixes produced by warm process can be reduced by adding ulexite mineral nano particles to a commercial additive. The Marshall stability, Indirect tensile strength modulus, and moisture susceptibility, were tested for this purpose. Based on the analysis of results, it can be seen that the WMA mixture production temperature can additionally be reduced, and that lower compaction energy is needed during placement of such mixtures, which results in energy savings

The Effect of Sodium Chloride on Concretes Containing Milled Colemanite

Bu çalışmada, %0 (Referans), %1, %2, %3, %4 ve %5 oranlarında öğütülmüş kolemanit minerali çimento ile ikame edilerek beton karışımları hazırlanmıştır. Beton karışımlar 150 x 150 x 150 mm boyutlu küp kalıplara yerleştirilmiştir. Sertleşmiş beton numuneler 28 gün suda kür edilerek, sonrasında 90. güne kadar sodyum klorür (NaCI) çözeltisine maruz bırakılmıştır. Ayrıca aynı özelliklerde üretilen kontrol beton örnekleri ise 90. güne kadar su küründe bekletilmiştir. Kontrol ve NaCI çözeltisine maruz bırakılmış beton numuneler üzerinde Schmidt çekici, ultrases geçiş hızı ve basınç dayanımı deneyleri gerçekleştirilmiştir. Gerçekleştirilen deneyler üzerinden beton numunelerin NaCI çözeltisinin etkisi ile meydana gelen kayıplar hesaplanmıştır Sonuç olarak, çimentoya ikame edilen %5 kolemanit ikameli numunenin, kolemanit içermeyen numuneye göre basınç dayanımını azalttığı, ancak %4’ kadar ikame oranlarında ise dayanımı arttırdığı tespit edilmiştir. NaCI çözeltisi kürü sonucunda, en yüksek basınç dayanımı ve en az basınç dayanımı kaybının %3 kolemanit ikameli beton karışımına ait olduğu tespit edilmiştir.In this study, concrete mixtures were prepared by substituting milled colemanite mineral with cement in the ratio of 0% (Reference), 1%, 2%, 3%, 4% and 5%. The concrete mixtures are placed in 150 x 150 x 150 mm cube molds. Hardened concrete samples were cured in water for 28 days and then exposed to sodium chloride (NaCl) solution until day 90. In addition, the control concrete samples produced with the same characteristics were kept in the water cure until the 90th day. Schmidt hammer, ultrasonic pulse velocity and compressive strength tests were performed on concrete samples exposed to control and NaCl solution. The losses occuring by the effect of NaCl solution of concrete samples were calculated. As a result, it was found that the strength of the sample with 5% colemanite decreased compared to the sample without colemanite, but the strengthes of samples with up to 4% colemanite increased. As a result of cured to NaCl solution, the highest compressive strength and minimum compressive strength losses were determined to belong to the sample with 3% colemanite

Öğütülmüş Kolemanit İçeren Betonlarda Sodyum Klorür Etkisi

Bu çalışmada, %0 (Referans), %1, %2, %3, %4 ve %5 oranlarında öğütülmüş kolemanit minerali çimento ile ikame edilerek beton karışımları hazırlanmıştır. Beton karışımlar 150 x 150 x 150 mm boyutlu küp kalıplara yerleştirilmiştir. Sertleşmiş beton numuneler 28 gün suda kür edilerek, sonrasında 90. güne kadar sodyum klorür (NaCI) çözeltisine maruz bırakılmıştır. Ayrıca aynı özelliklerde üretilen kontrol beton örnekleri ise 90. güne kadar su küründe bekletilmiştir. Kontrol ve NaCI çözeltisine maruz bırakılmış beton numuneler üzerinde Schmidt çekici, ultrases geçiş hızı ve basınç dayanımı deneyleri gerçekleştirilmiştir. Gerçekleştirilen deneyler üzerinden beton numunelerin NaCI çözeltisinin etkisi ile meydana gelen kayıplar hesaplanmıştır Sonuç olarak, çimentoya ikame edilen %5 kolemanit ikameli numunenin, kolemanit içermeyen numuneye göre basınç dayanımını azalttığı, ancak %4’ kadar ikame oranlarında ise dayanımı arttırdığı tespit edilmiştir. NaCI çözeltisi kürü sonucunda, en yüksek basınç dayanımı ve en az basınç dayanımı kaybının %3 kolemanit ikameli beton karışımına ait olduğu tespit edilmiştir

Severe 25-OH vitamin D deficiency as a reason for adverse pregnancy outcomes

Objective: There is a growing concern about the unfavorable effects of vitamin D deficiency in general population, including pregnant women, worldwide. The aim of this study is to evaluate the effect of severe maternal serum 25-OH vitamin D levels on adverse pregnancy outcomes in first trimester. Material and methods: Serum samples of 86 pregnant women in first trimester were collected prospectively from May 2017 to June 2017. Serum 25-OH vitamin D levels were analyzed by enzyme immunoassay method. Patients were classified according to maternal serum 25-OH vitamin D levels as group 1 (n¼34) 10ng/ml. The two groups were compared in terms of adverse pregnancy outcomes. Results: The mean 25-OH vitamin D levels of the total 86 pregnant women were 13.83 (6–48) ng/ml. 40% of the pregnant women had low level of 25-OH vitamin D levels (<10ng/ml). The adverse pregnancy outcomes were significantly increased in group 1 (p<.018). Conclusions: Maternal serum 25-OH vitamin D levels <10ng/ml is a risk factor for adverse pregnancy outcomes. 25-OH vitamin D levels should be screened in high-risk pregnant women and treated in case of deficiency

Myo-inositol oxygenese activity in second trimester of pregnancy: altered myoinositol catabolism in gestational diabetes mellitus

Objective: We aimed to determine myo-inositol oxygenase (MIOX) activity in gestational diabetes mellitus (GDM). Material and Methods: The insulin, HbA1c, and MIOX levels of 80 pregnant women were analysed after 75 g OGTT. Group I included patients with no risk factor for GDM, Group II: patients with high risk for GDM, and Group III: GDM patients. Results: Fasting plasma glucose and Homeostatic Model Assessment for Insulin Resistance index were significantly higher in GDM cases (Group 3). Regarding the MIOX levels, significantly higher levels were recorded at 0-h in Group 3 compared to Groups 1 and 2. Significant alteration in MIOX activity was found between 0- and 2-h in Group 3 compared to Groups 1 and 2 (p < .029). Conclusions: MIOX levels were higher in GDM cases so, it may be have a role in myo-inositol catabolism

Stability analyses of submicron-boron mineral prepared by mechanical milling process in concrete roads

WOS: 000380597900027The main objective of this study is to investigate the possibility of utilizing nano/submicron sized boron mineral (colemanite) in Portland cement concrete. Colemanite was obtained from a mine in three different sizes as -3 mm (C-3m), 75 mu m (C-75 mu) and -45 mu m (C-45 mu), respectively. the C-3m was ground by mechanical milling process in a high-energy ball mill and then passed througha 25 mu m (C-25 mu) sieve in order to obtain a smaller size/nano sized particles. the material information of these powders was investigated by using laser size analyzer, optical microscopes, and scanning electron microscope analyses. the particle size was respectively reduced for the C-3m, C-75 mu, C-45 mu and C-25 mu and therefore its homogeneity was improved. Five different ratios of Portland cement were used as 0.5%, 1%, 2%, 3% and 5% (wt). For each of rations, the C-75 mu, the C-45 mu, the C-25 mu different particle size colemanite and control samples (0%, no addition) were evaluated and 15 cm x 15 cm x 15cm cubic samples were produced. the fine and coarse aggregates were natural conventional aggregates. As a result, the highest compressive strength and elastic modulus were obtained in case colemanite with sizes C-75 mu and the C-45 mu added into the concrete in ratios 3% and 5%; and colemanite with a size of C-25 mu added into the concrete in ratios 1% and 0.5%, respectively. Since the C-25 mu is close to the ideal size of the cement, it becomes a good adherence by high specific surface area. Nano particle materials are used for their high specific surface area which has a great impact on the hydration. This is the reason why findings it could be observed that C-75 mu and C-45 mu required to be added at high percentage to probably have a concrete with the same mechanical properties as for C-25 mu that required a small percentage of addition. (C) 2016 Elsevier Ltd. All rights reserved.Recep Tayyip Erdogan University (RTEU) [BAP 2014.109.03.01]This study was funded by Recep Tayyip Erdogan University (RTEU) BAP 2014.109.03.01. the author also thanks Dr. Sezai KUTUK for milling and sieving the boron mineral and performing the physical property measurements; Cevahir Concrete Company, Ritas Concrete Company and M. Selcuk GUNER for producing concrete; Prof. Orhan KARSLI and Asst. Prof. Yilmaz DEMIR for optical microscopes; Assoc. Prof. Aykut CANAKCI for laser size analyzer; ETI Mine Works General Directorate for supplying boron mineral and Dr. Mustafa BARIS for choosing boron mineral type

Investigation of the Effect of Ulexite Mineral with Sub-Micron Sizes on Asphalt Mixtures Moisture Susceptibility

Yol kaplamalarında görülen erken bozulmalar ve deformasyonlar genellikle bitümlü kaplamaların maruz kaldıkları suyun varlığından kaynaklı bozulmalardır. Gerçekleştirilmiş olan bu çalışma sayesinde ülkemizde rezervi bulunan ve önemli bir bor minerali olan Üleksitin asfalt karışımlarındaki etkinliği araştırılmıştır. Bu çalışmada asıl üzerinde durulan husus, üleksit minerallerinin ticari olarak bulunabilen boyutlarıyla değil de nano partikül öğütücü değirmen ile öğütülerek küçük boyutlara getirilmiş halinin de çalışmaya dahil edilmiş olmasıdır. Bu bağlamda 25 mikron altı (U-25 µm) ve 53 mikron üstü (U+53 µm) şeklinde iki farklı boyutta üleksit mineralleri analiz edilmiştir. Özellikle U-25 malzemesinde nano boyutların yoğun olduğu görülmüştür. Bu minerallerin, bağlayıcı miktarının kütlece % 5'i ve %10'u mertebelerinde bitümlü karışımlara ilave edilerek hazırlanmış olan karışımlara suya hassasiyet testleri uygulanmıştır. Elde edilen sonuçlar göstermiştir ki; bor minerali katkısı karışımların suya karşı dirençlerini artırmıştır. Katkısız (referans) numunelerde koşullandırma ile mukavemet kaybı yaklaşık % 15 iken üleksit katkılı numunelerde yaklaşık %3-%4'ler mertebesinde olduğu görülmüştür.Early deterioration and deformations in road pavements with bituminous mixtures are usually caused by the presence of water. Thanks to this study, the effect of ulexite which is a major boron mineral with reserves in our country, has been investigated in asphalt mixtures. The main point in this study is that the small sized ulexite minerals are included in the study obtained by the nano particle grinding mill, not the commercially available sizes. In this regard, ulexite mineral with two different sizes as lower than 25 microns (U-25 µm) and upper than 53 micron (U+53 µm) was analyzed in this study. Particularly, in U-25 material, nano dimensions are seen to be dense. Moisture susceptibility tests were applied to the asphalt samples prepared by adding 5% and 10% ulexite minerals by the weight of bitumen in mixture. The results showed that the boron mineral additive in hot-mix asphalt mixtures improved the resistance of asphalt mixtures' moisture susceptibility. The loss of strength was found to be about 15% with the conditioning on the untreated (reference) samples, while it was found that the ulexite-added samples were in the range of about 3-4%

Investigation of Geogrid Aperture Size Effects on Subbasesubgrade Stabilization of Asphalt Pavements

The increased use of geogrids in highway pavement subbase layer reinforcement applications has resulted in a need to better understand the soil–geogrid interface properties for the use in analysis and design. For this purpose, a series of laboratory large scale pullout tests was carried out with three different aperture size geogrid samples randomly sampled from a single manufacturer. It was found that geogrids are unique in their pullout performance within pavement subbase layer structure based on their aperture sizes. Analysis indicates a strong relationship between pullout performance and geogrid aperture size of geogrids at moderate normal stress levels. Such findings aid in selection of appropriate geogrid types for subgrade and subbase interface reinforcement purposes. Further experimental analysis was conducted to investigate the wide-width tensile test performance for the same samples used in the pullout tests in this study

Effect of PCA on Nanosized Ulexite Material Prepared by Mechanical Milling

KUTUK, Sezai/0000-0002-0159-5953WOS: 000412995500027Raw ulexite (U-3 mm) mineral used as a initial material was milled by using mechanical milling method, the milling time of which is from 0 to 8 h. Particle size, morphology, elemental and crystal structure measurements of the U-3 mm material and milled powder (U_3%, process control agent amount: 3%) were performed. in particle size analysis, minimum d(50), d(10) and d(min) values of U_3% powder have been found to be 5.921 mu m, 641 nm and 240 nm, respectively. Therefore, it has been reached to submicron level in particle size for the U_3% powder. Besides, optimum milling time has been detected to be 0.5 h. in morphology analysis, the U_3% powder has been observed to be more homogeneous compared to the U-3 mm material. in the analysis of element, the U_3% powder has been determined not to be a pure compound (Na2O center dot 2CaO center dot 5B(2)O(3)center dot 16H(2)O). in crystal structure analysis, crystalline size of the U_3% powder has reduced to 10.3 nm at the end of 8 h. Moreover, crystal structure deformation caused by milling process of the U-3 mm material has improved thanks to PCA. the findings obtained from this work will be beneficial for nanoworks and industrial applications, e.g., civil engineering-pavement engineering materials, of ulexite (boron mineral) material.Recep Tayyip Erdogan UniversityRecep Tayyip Erdogan University [2014.109.03.01]This study which the authors have received research grant was funded by Recep Tayyip Erdogan University (Grant No. 2014.109.03.01). Authors thank Eti Mine Company for providing ulexite mineral; Assoc. Prof. A. Canakci for using laser size analyzer and Asst. Prof. Y. Demir for using optical microscope