NO<SUB>x</SUB> emission modeling at cement plants with co-processing alternative fuels using ANN

Betul OZTURK,Onur OZTURK,Aykan KARADEM?R 대한환경공학회 2022 Environmental Engineering Research Vol.27 No.5

The use of wastes as alternative fuel (AF) at the cement plants for clinkerization processes has increased in recent years as sustainable waste management. Such co-processing of AFs at cement plants causes some changes in the composition of the plant emissions, depending on waste type, kiln thermal power, thermal substitution rate, etc. Emissions of nitrogen oxides (NOx) are among the major environmental concerns in these plants. The paper includes a modeling study of NOx emissions at a cement plant during the co-processing of AFs. Due to the non-linear characteristic of the relationship between operational parameters and NOx emissions, the artificial neural network (ANN) approach was applied and studied. The study showed that NOx emissions can be predicted satisfactorily by using ANN at cement plants. Therefore, the model proposed may be used by cement plant operators to estimate their emission levels before starting the use of a new fuel source.

A Characterization of Involutes and Evolutes of a Given Curve in 𝔼ⁿ

Ozturk, Gunay,Arslan, Kadri,Bulca, Betul Department of Mathematics 2018 Kyungpook mathematical journal Vol.58 No.1

The orthogonal trajectories of the first tangents of the curve are called the involutes of x. The hyperspheres which have higher order contact with a curve x are known osculating hyperspheres of x. The centers of osculating hyperspheres form a curve which is called generalized evolute of the given curve x in n-dimensional Euclidean space ${\mathbb{E}}^n$. In the present study, we give a characterization of involute curves of order k (resp. evolute curves) of the given curve x in n-dimensional Euclidean space ${\mathbb{E}}^n$. Further, we obtain some results on these type of curves in ${\mathbb{E}}^3$ and ${\mathbb{E}}^4$, respectively.

Tensor product surfaces with pointwise 1-type Gauss map

Kadri Arslan,Betul Bulca,Bengu Kilic,Young Ho Kim,Cengizhan Murathan,Gunay Ozturk 대한수학회 2011 대한수학회보 Vol.48 No.3

Tensor product immersions of a given Riemannian manifold was initiated by B.-Y. Chen. In the present article we study the tensor product surfaces of two Euclidean plane curves. We show that a tensor product surface M of a plane circle c_1 centered at origin with an Euclidean planar curve c_2 has harmonic Gauss map if and only if M is a part of a plane. Further, we give necessary and sufficient conditions for a tensor product surface M of a plane circle c_1 centered at origin with an Euclidean planar curve c_2 to have pointwise 1-type Gauss map.

TENSOR PRODUCT SURFACES WITH POINTWISE 1-TYPE GAUSS MAP

Arslan, Kadri,Bulca, Betul,Kilic, Bengu,Kim, Young-Ho,Murathan, Cengizhan,Ozturk, Gunay Korean Mathematical Society 2011 대한수학회보 Vol.48 No.3

Tensor product immersions of a given Riemannian manifold was initiated by B.-Y. Chen. In the present article we study the tensor product surfaces of two Euclidean plane curves. We show that a tensor product surface M of a plane circle $c_1$ centered at origin with an Euclidean planar curve $c_2$ has harmonic Gauss map if and only if M is a part of a plane. Further, we give necessary and sufficient conditions for a tensor product surface M of a plane circle $c_1$ centered at origin with an Euclidean planar curve $c_2$ to have pointwise 1-type Gauss map.

Dynamic thiol/disulfide homeostasis as a novel indicator of oxidative stress in patients with urolithiasis

Mehmet Giray Sonmez,Betul Kozanhan,Çigdem Damla Deniz,Mehmet Sinan Iyisoy,Muzaffer Tansel Kilinc,Gokhan Ecer,Ahmet Ozturk,Salim Neselioglu,Ozcan Erel 대한비뇨의학회 2019 Investigative and Clinical Urology Vol.60 No.4

Purpose: A dynamic thiol/disulfide balance is pivotal in organizing anti-oxidant defense, detoxification, apoptosis, and enzyme activities, as well as transcription and cellular signal-transfer mechanisms. The connection between urolithiasis and oxidant/antioxidant status, which can be assessed through thiol-disulfide homeostasis (TDH), has not yet been examined. In this study, we evaluated the effects of TDH on the formation, size, and location of stones by examining the associations between TDH parameters and urolithiasis. Materials and Methods: Patients with urolithiasis and healthy controls were recruited. The patients were divided into subgroups in terms of stone size (>15 mm or ≤15 mm) and stone location (nephrolithiasis or ureterolithiasis). TDH parameters were measured using a novel automatic and spectrophotometric method and compared statistically. Results: TDH parameters were different between the urolithiasis and control groups. TDH tended towards the disulfide side in the urolithiasis group. Stone size increased an average 0.14 mm with a 1 µmol/L increase in disulfide level and decreased an average 0.058 mm with a 1 µmol/L increase in native thiol level. Disulfide and native thiol levels were found to be different across patients with stone size >15 mm, ≤15 mm, and controls (p<0.001 and p<0.001, respectively). However, the nephrolithiasis and ureterolithiasis groups were similar in respect of TDH parameters. Conclusions: In this study, it was found that patients with urolithiasis displayed oxidative stress characterized by a TDH tendency towards the disulfide side, and an inadequate antioxidant response identified by a lower level of native thiol as compared with healthy controls.

Vancomycin Loaded Gelatin Microspheres Containing Wet Spun Poly(ε-caprolactone) Fibers and Films for Osteomyelitis Treatment

Eda Ayse Aksoy,Betul Suyumbike Yagci,Gulseher Manap,Ipek Eroglu,Sukru Ozturk,Melike Ekizoglu,Kezban Ulubayram 한국섬유공학회 2019 Fibers and polymers Vol.20 No.11

In this study, it was aimed to develop drug eluting biodegradable and biocompatible bone supportive fibers andfilms, which can locally be applicable on the infected bone defect area for osteomyelitis treatment. For this purpose,vancomycin (Vm) loaded gelatin (G) microspheres were prepared and dispersed into poly(ε-caprolactone) (PCL) solutionand then the suspension was processed as films and fibers by solvent casting and wet spinning techniques, respectively. Themean particle size distribution and morphology of Vm loaded G microspheres were characterized by laser diffraction methodand scanning electron microscopy, respectively. In vitro Vm release profiles and release kinetics from microsphere, fiber andfilm formulations were investigated. In vitro biodegradation properties of fiber and film formulations were examined in bothhydrolytic and enzymatic media during 25 days period. The cytotoxicity of Vm eluting films and fibers were tested on L929cells by MTT assay. Presence of PCL in film and fiber formulations retarded the release of Vm from microspheres andprovided long term sustained release. Vm eluting films and fibers exhibited strong antibacterial properties againstStaphylococcus aureus and Staphylococcus epidermidis.

Measurement of Contrast Sensitivity in Patients with Behçet’s Disease without Ocular Involvement

Ercan Ozsoy,Cem Cankaya,Emrah Ozturk,Abuzer Gunduz,Pamuk Betul Ulucan 대한안과학회 2019 Korean Journal of Ophthalmology Vol.33 No.2

Purpose: To evaluate contrast sensitivity in patients with Behçet’s disease (BD) without ocular involvement. Methods: The study group was composed of 47 BD patients (20 to 50 years of age) who did not have ocular involvement. The control group was composed of 47 normal volunteers who were similar to the study group in terms of age and gender. No participants in this study had any ocular or systemic pathologies except for BD. The contrast sensitivity measurements were performed using the Functional Acuity Contrast Test under photopic conditions, and the results were compared between the two groups. Results: The mean age of the BD patients and control subjects was 34.5 ± 9.7 and 33.2 ± 7.6 years, respectively. The mean disease duration of the BD patients was 5.5 ± 6.4 years. There was a statistically significant decrease at five spatial frequencies (A, 1.5; B, 3; C, 6; D, 2; and E, 18 cycles per degree) in patients with BD compared with control subjects (p < 0.001, p = 0.004, p = 0.002, p < 0.001, and p = 0.001, respectively). Conclusions: The contrast sensitivity of BD patients without ocular involvement was lower than that of the control group. Further studies seem mandatory to confirm our results.