GENERALIZED LUCAS NUMBERS OF THE FORM 5kx2 AND 7kx2

Olcay Karaatli,Refik Keskin 대한수학회 2015 대한수학회보 Vol.52 No.5

Generalized Fibonacci and Lucas sequences (Un) and (Vn) are defined by the recurrence relations Un+1 = PUn+QUn−1 and Vn+1 = PVn +QVn−1, n ≥ 1, with initial conditions U0 = 0, U1 = 1 and V0 = 2, V1 = P. This paper deals with Fibonacci and Lucas numbers of the form Un(P,Q) and Vn(P,Q) with the special consideration that P ≥ 3 is odd and Q = −1. Under these consideration, we solve the equations Vn = 5kx2, Vn = 7kx2, Vn = 5kx2±1, and Vn = 7kx2±1 when k | P with k > 1. Moreover, we solve the equations Vn = 5x2 ±1 and Vn = 7x2 ± 1.

Large Thrombus Formation from Right Atrial Incision Site after Closure of Atrial Septal Defect

Olcay Murat Disli,Nevzat Erdil,Barıs Akca,Yılmaz Omur Otlu,Bektas Battaloglu 대한심장학회 2013 Korean Circulation Journal Vol.43 No.12

Atrial septal defect (ASD) is the common congenital anomaly which requires surgical interventions. Right atrial thrombus formations after primary suture repairs of the ASD and evidences of thromboembolic complications are extremely rare. Specifically, the cases of thromboembolic complications have high mortality and morbidity risks. Two cases of giant intra-atrial thrombus formation detected in the late stage after primary repairs of ASDs are being discussed.

Biostimulating Effects of Disintegrated Waste Activated Sludge on Soil Enzyme Activities

Fatma Olcay Topac,Canan Etyam 대한토목학회 2021 KSCE JOURNAL OF CIVIL ENGINEERING Vol.25 No.7

Sludge disintegration methods are used in a variety of applications to enhance sludge characteristics or bring about a reduction in solid content of sludge. Hydrodynamic cavitation is one of the mechanical disintegration methods used on waste-activated sludge, and its efficiency has been investigated in recent years. In this study, the possible use of waste-activated sludge disintegrated by hydrodynamic cavitation and chemically assisted hydrodynamic cavitation as a soil amendment was evaluated by an incubation procedure. Possible biostimulating effects were assessed by monitoring the variations in soil enzyme activities. The obtained results indicated that sludge solubilization was effectively performed with respect to soluble chemical oxygen demand, soluble total Kjeldahl nitrogen and soluble total phosphorus. According to the incubation study, the biostimulating/bioremediating properties of waste-activated sludge were significantly improved by the applied methods. Especially after a 60-day incubation period, the levels of urease, alkaline phosphatase, β-glucosidase and dehydrogenase activities in soils applied with a high dose of disintegrated sludge were significantly higher than the levels in raw sludge-amended soils. Consequently, it is thought that mechanically and chemically disintegrated waste-activated sludge with reduced numbers of indicator bacteria can be considered as a way of soil amendment to rehabilitate the quality of environmentally stressed soils.

Familial gigantiform cementoma with Ehlers - Danlos syndrome: A report of 2 cases

Sakar, Olcay,Aren, Gamze,Mumcu, Zeynep,Unalan, Fatma,Aksakalli, Nihan,Tolgay, Ceren Guney The Korean Academy of Prosthodonitics 2015 The Journal of Advanced Prosthodontics Vol.7 No.2

Ehlers-Danlos syndrome is an autosomal dominant hereditary disorder of connective tissue, while familial gigantiform cementoma is a condition that usually manifests as multiple radiopaque cementum-like masses throughout the jaws. This case report discusses the oral management and prosthetic rehabilitation of two patients presenting familial gigantiform cementoma with Ehlers-Danlos Syndrome.

GENERALIZED LUCAS NUMBERS OF THE FORM 5kx² AND 7kx²

KARAATLI, OLCAY,KESKIN, REFIK Korean Mathematical Society 2015 대한수학회보 Vol.52 No.5

Generalized Fibonacci and Lucas sequences ($U_n$) and ($V_n$) are defined by the recurrence relations $U_{n+1}=PU_n+QU_{n-1}$ and $V_{n+1}=PV_n+QV_{n-1}$, $n{\geq}1$, with initial conditions $U_0=0$, $U_1=1$ and $V_0=2$, $V_1=P$. This paper deals with Fibonacci and Lucas numbers of the form $U_n$(P, Q) and $V_n$(P, Q) with the special consideration that $P{\geq}3$ is odd and Q = -1. Under these consideration, we solve the equations $V_n=5kx^2$, $V_n=7kx^2$, $V_n=5kx^2{\pm}1$, and $V_n=7kx^2{\pm}1$ when $k{\mid}P$ with k > 1. Moreover, we solve the equations $V_n=5x^2{\pm}1$ and $V_n=7x^2{\pm}1$.

Experimental design approach for ultra-fast nickel removal by novel bio-nanocomposite material

Ince, Olcay K.,Aydogdu, Burcu,Alp, Hevidar,Ince, Muharrem Techno-Press 2021 Advances in nano research Vol.10 No.1

In the present study, novel chitosan coated magnetic magnetite (Fe3O4) nanoparticles were successfully biosynthesized from mushroom, Agaricus campestris, extract. The obtained bio-nanocomposite material was used to investigate ultra-fast and highly efficient for removal of Ni2+ ions in a fixed-bed column. Chitosan was treated as polyelectrolyte complex with Fe3O4 nanoparticles and a Fungal Bio-Nanocomposite Material (FBNM) was derived. The FBNM was characterized by using X-Ray Diffractometer (XRD), Scanning Electron Microscopy-Energy Dispersive X-Ray Spectroscopy (SEM-EDS), Fourier Transform Infrared spectra (FTIR) and Thermogravimetric Analysis (TGA) techniques and under varied experimental conditions. The influence of some important operating conditions including pH, flow rate and initial Ni2+ concentration on the uptake of Ni2+ solution was also optimized using a synthetic water sample. A Central Composite Design (CCD) combined with Response Surface Modeling (RSM) was carried out to maximize Ni2+ removal using FBNM for adsorption process. A regression model was derived using CCD to predict the responses and analysis of variance (ANOVA) and lack of fit test was used to check model adequacy. It was observed that the quadratic model, which was controlled and proposed, was originated from experimental design data. The FBNM maximum adsorption capacity was determined as 59.8 mg g-1. Finally, developed method was applied to soft drinks to determine Ni2+ levels. Reusability of FBNM was tested, and the adsorption and desorption capacities were not affected after eight cycles. The paper suggests that the FBNM is a promising recyclable nanoadsorbent for the removal of Ni2+ from various soft drinks.

Variance-mean mixture of multivariate normal distribution and weighted gamma distribution: properties and applications

Doğru Fatma Zehra,Arslan Olcay 한국통계학회 2023 Journal of the Korean Statistical Society Vol.52 No.1

In this paper, we propose a weighted extension of the family of multivariate Generalized Asymmetric Laplace (GAL) distributions. This extension is formed as a variance-mean mixture of the multivariate normal distribution and the weighted gamma distribution. By using the weighted gamma distribution as the mixing distribution, the resulting family of weighted GAL (WGAL) distributions gains an additional parameter to further regulate kurtosis and tail thickness; this is an advantage over the family of GAL distributions for modeling data sets. In particular, this new parameter provides great flexibility in adjusting the kurtosis and tail thickness for some members of the GAL distributions family, since these distributions are the widely used members of the GAL family without any shape parameter regulating kurtosis and tail thickness. After defning the multivariate WGAL distributions family and constructing the probability density function, we give some special cases of the new family and examine various properties of the new distributions, such as linear transformations, conditional distributions, and multivariate kurtosis measure. We study the maximum likelihood (ML) estimation to estimate the parameters and describe an algorithm based on the expectation maximization (EM) principle to obtain the ML estimates. We also provide simulation studies and real data examples to explore the modeling capacity of some distributions belonging to the newly proposed family of distributions.

Biodegradation of Crude Oil-contaminated Soil using Canned-food-industry Wastewater Sludge for Soil Application

Efsun Dindar,F. Olcay Topaç Şağban,Hüseyin S. Başkaya 대한토목학회 2017 KSCE JOURNAL OF CIVIL ENGINEERING Vol.21 No.5

The objective of this study was to evaluate the effects of crude oil (application doses of 0.5% and 5%) from hydrocarbon contamination on the removal of the Total Petroleum Hydrocarbons (TPH) from soil and to determine the removal of TPH at different temperatures (18°C and 28°C) during an incubation period of 240 days. The possible use of wastewater sludge as a biostimulating agent in crude oil-contaminated soils was also evaluated. The results of the 240 days of incubation indicated that the TPH removal percentages in crude oil-contaminated and sludge-treated soils at 18°C were 89% and 79%, for doses of 0.5 and 5%, respectively. Incubation at 28°C resulted in higher TPH removal with removal percentages of 83% (dose of 0.5%) and 91% (dose of 5%). The degradation of crude oil in contaminated soil treated with a 5% dose was significantly enhanced by the addition of wastewater sludge, whereas no apparent biostimulating effect on TPH removal was observed in the case of low-dose (0.5%) crude oil contamination.

Effect of Orifice Induced Hydrodynamic Cavitation on the Properties of Waste Activated Sludge

Esra Demir Karaçoban,Fatma Olcay Topaç,Efsun Dindar,Bülent Keskinler 대한토목학회 2024 KSCE Journal of Civil Engineering Vol.28 No.4

Exploring alternative methods to reduce the quantity of wastewater sludge and improve its characteristics is among the prioritized subjects in the field of sludge management. Hydrodynamic cavitation, commonly employed for water and wastewater treatment, also holds the potential for utilization as a pre-treatment method for sludge. In the presented study, the excess sludge obtained from the wastewater treatment facility of a food and beverage manufacturing factory was collected and disintegrated with a orifice-induced hydrodynamic cavitation unit. According to the data obtained, the highest cavitation performance was achieved under the condition where the cavitation number was set to 0.3. In addition, hydrodynamic cavitation performed under the optimum operating conditions, significantly increased the solubility of waste activated sludge. The results showed that the soluble chemical oxygen demand concentration, which was initially determined as 382 mg/l, reached 3,068 mg/l end of the cavitation. 64% of the total Kjeldahl nitrogen and 60% of the total phosphorus of waste-activated sludge were converted into soluble forms by the effects of hydrodynamic cavitation. Moreover, the results of the microbial study indicated that removal rates of indicator bacteria varied between 94% and 99%.

Stereological and Morphometric Analysis of MRI Chiari Malformation Type-1

Alkoc, Ozan Alper,Songur, Ahmet,Eser, Olcay,Toktas, Muhsin,Gonul, Yucel,Esi, Ertap,Haktanir, Alpay The Korean Neurosurgical Society 2015 Journal of Korean neurosurgical society Vol.58 No.5

Objective : In this study, we aimed to investigate the underlying ethiological factors in chiari malformation (CM) type-I (CMI) via performing volumetric and morphometric length-angle measurements. Methods : A total of 66 individuals [33 patients (20-65 years) with CMI and 33 control subjects] were included in this study. In sagittal MR images, tonsillar herniation length and concurrent anomalies were evaluated. Supratentorial, infratentorial, and total intracranial volumes were measured using Cavalieri method. Various cranial distances and angles were used to evaluate the platybasia and posterior cranial fossa (PCF) development. Results : Tonsillar herniation length was measured $9.09{\pm}3.39mm$ below foramen magnum in CM group. Tonsillar herniation/concurrent syringomyelia, concavity/defect of clivus, herniation of bulbus and fourth ventricle, basilar invagination and craniovertebral junction abnormality rates were 30.3, 27, 18, 2, 3, and 3 percent, respectively. Absence of cisterna magna was encountered in 87.9% of the patients. Total, IT and ST volumes and distance between Chamberlain line and tip of dens axis, Klaus index, clivus length, distance between internal occipital protuberance and opisthion were significantly decreased in patient group. Also in patient group, it was found that Welcher basal angle/Boogard angle increased and tentorial slope angle decreased. Conclusion : Mean cranial volume and length-angle measurement values significantly decreased and there was a congenital abnormality association in nearly 81.5 percent of the CM cases. As a result, it was concluded that CM ethiology can be attributed to multifactorial causes. Moreover, congenital defects can also give rise to this condition.