Adsorption and column flotation studies on talc using anionic and cationic collectors

Hulya Kursun,Ayten Ates 한국화학공학회 2010 Korean Journal of Chemical Engineering Vol.27 No.6

Adsorption properties and column flotation were studied to investigate the interaction of the anionic and cationic collectors and flotation recoveries for talc mineral. Adsorption capacity is dependent on pH, adsorption time,temperature, collector concentration, and particle size. Langmuir adsorption model was suitable for describing isotherms. Analyses were carried out using UV spectrometry. In this study, we analyzed some parameters affecting column flotation performance. It was determined that adsorption capacity, especially, had an important role in column flotation enrichment.

Florid osseous dysplasia in a middle-aged Turkish woman: A case report

Onder, Buket,Kursun, Sebnem,Oztas, Bengi,Baris, Emre,Erdem, Erdal Korean Academy of Oral and Maxillofacial Radiology 2013 Imaging Science in Dentistry Vol.43 No.3

Florid osseous dysplasia (FOD) is an uncommon, benign, cemento-osseous lesion of the jaws. The etiology of FOD is still unknown. It is often asymptomatic and may be identified on routine dental radiographs. The classic radiographic appearance of FOD is amorphous, lobulated, mixed radiolucent/radiopaque masses of cotton-wool appearance with a sclerotic border in the jaws. In our case the lesion was found incidentally on routine periapical radiographs taken for restored teeth and edentulous areas. For further and detailed examination, a panoramic radiograph and cone-beam computed tomograph (CBCT) were taken. The panoramic radiograph and CBCT revealed maxillary bilateral and symmetrical, non-expansile, well-defined, round, radiopaque masses in contact with the root of the maxillary right second molar and left first molar teeth. Our aim in presenting this case report was to highlight the importance of imaging in diagnosis of FOD.

Accuracy of virtual models in the assessment of maxillary defects

Kamburoglu, Kivanc,Kursun, Sebnem,Kilic, Cenk,Ozen, Tuncer Korean Academy of Oral and Maxillofacial Radiology 2015 Imaging Science in Dentistry Vol.45 No.1

Purpose: This study aimed to assess the reliability of measurements performed on three-dimensional (3D) virtual models of maxillary defects obtained using cone-beam computed tomography (CBCT) and 3D optical scanning. Materials and Methods: Mechanical cavities simulating maxillary defects were prepared on the hard palate of nine cadavers. Images were obtained using a CBCT unit at three different fields-of-views (FOVs) and voxel sizes: 1) $60{\times}60mm$ FOV, $0.125mm^3$ ($FOV_{60}$); 2) $80{\times}80mm$ FOV, $0.160mm^3$ ($FOV_{80}$); and 3) $100{\times}100mm$ FOV, $0.250mm^3$ ($FOV_{100}$). Superimposition of the images was performed using software called VRMesh Design. Automated volume measurements were conducted, and differences between surfaces were demonstrated. Silicon impressions obtained from the defects were also scanned with a 3D optical scanner. Virtual models obtained using VRMesh Design were compared with impressions obtained by scanning silicon models. Gold standard volumes of the impression models were then compared with CBCT and 3D scanner measurements. Further, the general linear model was used, and the significance was set to p=0.05. Results: A comparison of the results obtained by the observers and methods revealed the p values to be smaller than 0.05, suggesting that the measurement variations were caused by both methods and observers along with the different cadaver specimens used. Further, the 3D scanner measurements were closer to the gold standard measurements when compared to the CBCT measurements. Conclusion: In the assessment of artificially created maxillary defects, the 3D scanner measurements were more accurate than the CBCT measurements.

N-Type Carbon-Nanotube MOSFET Device Profile Optimization for Very Large Scale Integration

Sun, Yanan,Kursun, Volkan The Korean Institute of Electrical and Electronic 2011 Transactions on Electrical and Electronic Material Vol.12 No.2

Carbon-nanotube metal oxide semiconductor field effect transistor (CN-MOSFET) is a promising future device candidate. The electrical characteristics of 16 nm N-type CN-MOSFETs are explored in this paper. The optimum N-type CN-MOSFET device profiles with different number of tubes are identified for achieving the highest on-state to off-state current ratio ($I_{on}/I_{off}$). The influence of substrate voltage on device performance is also investigated in this paper. Tradeoffs between subthreshold leakage current and overall switch quality are evaluated with different substrate bias voltages. Technology development guidelines for achieving high-speed, low-leakage, area efficient, and manufacturable carbon nanotube integrated circuits are provided.

FinFET SRAM Cells with Asymmetrical Bitline Access Transistors for Enhanced Read Stability

Shairfe Muhammad Salahuddin,Volkan Kursun,Hailong Jiao 한국전기전자재료학회 2015 Transactions on Electrical and Electronic Material Vol.16 No.6

Degraded data stability, weaker write ability, and increased leakage power consumption are the primary concerns in scaled static random-access memory (SRAM) circuits. Two new SRAM cells are proposed in this paper for achieving enhanced read data stability and lower leakage power consumption in memory circuits. The bitline access transistors are asymmetrically gate-underlapped in the proposed SRAM cells. The strengths of the asymmetric bitline access transistors are weakened during read operations and enhanced during write operations, as the direction of current flow is reversed. With the proposed hybrid asymmetric SRAM cells, the read data stability is enhanced by up to 71.6% and leakage power consumption is suppressed up to 15.5%, while displaying similar write voltage margin and maintaining identical silicon area as compared to the conventional memory cells in a 15 nm FinFET technology.

N-Type Carbon-Nanotube MOSFET Device Profile Optimization for Very Large Scale Integration

Yanan Sun,Volkan Kursun 한국전기전자재료학회 2011 Transactions on Electrical and Electronic Material Vol.12 No.2

Carbon-nanotube metal oxide semiconductor field effect transistor (CN-MOSFET) is a promising future device candidate. The electrical characteristics of 16 nm N-type CN-MOSFETs are explored in this paper. The optimum N-type CN-MOSFET device profiles with different number of tubes are identified for achieving the highest on-state to off-state current ratio (I_(on)/I_(off)). The influence of substrate voltage on device performance is also investigated in this paper. Tradeoffs between subthreshold leakage current and overall switch quality are evaluated with different substrate bias voltages. Technology development guidelines for achieving high-speed, low-leakage, area efficient, and manufacturable carbon nanotube integrated circuits are provided.

FinFET SRAM Cells with Asymmetrical Bitline Access Transistors for Enhanced Read Stability

Salahuddin, Shairfe Muhammad,Kursun, Volkan,Jiao, Hailong The Korean Institute of Electrical and Electronic 2015 Transactions on Electrical and Electronic Material Vol.16 No.6

Degraded data stability, weaker write ability, and increased leakage power consumption are the primary concerns in scaled static random-access memory (SRAM) circuits. Two new SRAM cells are proposed in this paper for achieving enhanced read data stability and lower leakage power consumption in memory circuits. The bitline access transistors are asymmetrically gate-underlapped in the proposed SRAM cells. The strengths of the asymmetric bitline access transistors are weakened during read operations and enhanced during write operations, as the direction of current flow is reversed. With the proposed hybrid asymmetric SRAM cells, the read data stability is enhanced by up to 71.6% and leakage power consumption is suppressed up to 15.5%, while displaying similar write voltage margin and maintaining identical silicon area as compared to the conventional memory cells in a 15 nm FinFET technology.

Accuracy of virtual models in the assessment of maxillary defects

Kıvanc Kamburoglu,Sebnem Kursun,Cenk Kılıc,Tuncer Özen 대한영상치의학회 2015 Imaging Science in Dentistry Vol.45 No.1

Purpose: This study aimed to assess the reliability of measurements performed on three-dimensional (3D) virtual models of maxillary defects obtained using cone-beam computed tomography (CBCT) and 3D optical scanning. Materials and Methods: Mechanical cavities simulating maxillary defects were prepared on the hard palate of nine cadavers. Images were obtained using a CBCT unit at three different fields-of-views (FOVs) and voxel sizes: 1) 60×60 mm FOV, 0.125 mm3 (FOV60); 2) 80×80 mm FOV, 0.160 mm3 (FOV80); and 3) 100×100 mm FOV, 0.250 mm3 (FOV100). Superimposition of the images was performed using software called VRMesh Design. Automated volume measurements were conducted, and differences between surfaces were demonstrated. Silicon impressions obtained from the defects were also scanned with a 3D optical scanner. Virtual models obtained using VRMesh Design were compared with impressions obtained by scanning silicon models. Gold standard volumes of the impression models were then compared with CBCT and 3D scanner measurements. Further, the general linear model was used, and the significance was set to p=0.05. Results: A comparison of the results obtained by the observers and methods revealed the p values to be smaller than 0.05, suggesting that the measurement variations were caused by both methods and observers along with the different cadaver specimens used. Further, the 3D scanner measurements were closer to the gold standard measurements when compared to the CBCT measurements. Conclusion: In the assessment of artificially created maxillary defects, the 3D scanner measurements were more accurate than the CBCT measurements.