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239 results on '"Yazici, E"'

1. Orthogonal cycle systems with cycle length less than 10

Author

Kucukcifci, Selda and Yazici, E. Sule

Subjects
Mathematics - Combinatorics, 05C38, 05B15, 05B30
Abstract

An $H$-decomposition of $G$ is a partition of the edge-set of $G$ into subsets, where each subset induces a copy of the graph $H$. A $k$-orthogonal $H$-decomposition of a graph $G$ is a set of $k$ $H$-decompositions of $G$, such that any two copies of $H$ in distinct $H$-decompositions intersect in at most one edge. When $G=K_v$ we call the $H$-decomposition an $H$-system of order $v$. In this paper we consider the case $H$ is an $l$-cycle and construct a pair of orthogonal $l$-cycle systems for all admissible orders when $l=5,6,7, 8\ or\ 9$, except $(l,v)=(7,7)$ and $(l,v)=(9,9)$.

Published
2023

2. QC-LDPC Codes from Difference Matrices and Difference Covering Arrays

Author

Donovan, Diane, Rao, Asha, Üsküplü, Elif, and Yazıcı, E. Ş.

Subjects
Mathematics - Combinatorics, Computer Science - Information Theory
Abstract

We give a framework for generalizing LDPC code constructions that use Transversal Designs or related structures such as mutually orthogonal Latin squares. Our construction offers a broader range of code lengths and codes rates. Similar earlier constructions rely on the existence of finite fields of order a power of a prime. In contrast the LDPC codes constructed here are based on difference matrices and difference covering arrays, structures available for any order $a$. They satisfy the RC constraint and have, for $a$ odd, length $a^2$ and rate $1-\frac{4a-3}{a^2}$, and for $a$ even, length $a^2-a$ and rate at least $1-\frac{4a-6}{a^2-a}$. When $3$ does not divide $a$, these LDPC codes have stopping distance at least $8$. When $a$ is odd and both $3$ and $5$ do not divide $a$, our construction delivers an infinite family of QC-LDPC codes with minimum distance at least $10$. The simplicity of the construction allows us to theoretically verify these properties and analytically determine lower bounds for the minimum distance and stopping distance of the code. The BER and FER performance of our codes over AWGN (via simulation) is at the least equivalent to codes constructed previously, while in some cases significantly outperforming them.

Published
2022

3. Biembeddings of cycle systems using integer Heffter arrays

Author

Cavenagh, Nicholas J., Donovan, D., and Yazici, E. Ş.

Subjects
Mathematics - Combinatorics
Abstract

In this paper we will show the existence of a face $2$-colourable biembedding of the complete graph onto an orientable surface where each face is a cycle of a fixed length $k$, for infinitely many values of $k$. In particular, under certain conditions, we show that there exists at least $(n-2)[(p-2)!]^2/(e^2 kn)$ non-isomorphic face $2$-colourable biembeddings of $K_{2nk+1}$ in which all faces are cycles of length $k=4p+3$. These conditions are: $n\equiv 1\mod 4$, $k\equiv 3\mod 4$ and either $n$ is prime or $n\gg k$ and $n\equiv 0\mod 3$ implies $p\equiv 1\mod 3$. To achieve this result we begin by verifying the existence of $(n-2)[(p-2)!/e]^2$ non-equivalent Heffter arrays, $H(n;k)$, which satisfy the conditions: (1) for each row and each column the sequential partial sums determined by the natural ordering must be distinct modulo $2nk+1$; (2) the composition of the natural orderings of the rows and columns is equivalent to a single cycle permutation on the entries in the array. The existence of Heffter arrays $H(n;k)$ that satisfy condition (1) was established earlier in \cite{BCDY} and in this current paper we vary this construction and show that there are at least $(n-2)[(p-2)!/e]^2$ such non-equivalent $H(n;k)$ that satisfy condition (1) and then show that each of these Heffter arrays also satisfy condition (2) under certain conditions., Comment: arXiv admin note: text overlap with arXiv:1906.07366

Published
2019

4. Globally simple Heffter arrays $H(n;k)$ when $k\equiv 0,3\mod 4$

Author

Burrage, K., Cavenagh, Nicholas J., Donovan, D., and Yazıcı, E. Ş.

Subjects
Mathematics - Combinatorics
Abstract

Square Heffter arrays are $n\times n$ arrays such that each row and each column contains $k$ filled cells, each row and column sum is divisible by $2nk+1$ and either $x$ or $-x$ appears in the array for each integer $1\leq x\leq nk$. Archdeacon noted that a Heffter array, satisfying two additional conditions, yields a face $2$-colourable embedding of the complete graph $K_{2nk+1}$ on an orientable surface, where for each colour, the faces give a $k$-cycle system. Moreover, a cyclic permutation on the vertices acts as an automorphism of the embedding. These necessary conditions pertain to cyclic orderings of the entries in each row and each column of the Heffter array and are: (1) for each row and each column the sequential partial sums determined by the cyclic ordering must be distinct modulo $2nk+1$; (2) the composition of the cyclic orderings of the rows and columns is equivalent to a single cycle permutation on the entries in the array. We construct Heffter arrays that satisfy condition (1) whenever (a) $k\equiv 0\mod 4$; or (b) $n\equiv 1\mod 4$ and $k\equiv 3\mod 4$; or (c) $n\equiv 0\mod 4$, $k\equiv3\mod 4$ and $n\gg k$. As corollaries to the above we obtain pairs of orthogonal $k$-cycle decompositions of $K_{2nk+1}$.

Published
2019

5. AB1495 TELEDERMATOLOGY FOR RHEUMATOLOGISTS

Author

Kenar, G., primary, Şahin, C., additional, Yazici, E. I., additional, Tuğrul, B., additional, Güner, A., additional, Göğebakan, H., additional, Gencer, A. M., additional, and Yarkan-Tuğsal, H., additional

Published
2024
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7. High Rate LDPC Codes from Difference Covering Arrays

Author

Donovan, D., Rao, A., and Yazıcı, E. Şule

Subjects
Mathematics - Combinatorics, Computer Science - Information Theory, 05B10
Abstract

This paper presents a combinatorial construction of low-density parity-check (LDPC) codes from difference covering arrays. While the original construction by Gallagher was by randomly allocating bits in a sparse parity-check matrix, over the past 20 years researchers have used a variety of more structured approaches to construct these codes, with the more recent constructions of well-structured LDPC coming from balanced incomplete block designs (BIBDs) and from Latin squares over finite fields. However these constructions have suffered from the limited orders for which these designs exist. Here we present a construction of LDPC codes of length $4n^2 - 2n$ for all $n$ using the cyclic group of order $2n$. These codes achieve high information rate (greater than 0.8) for $n \geq 8$, have girth at least 6 and have minimum distance 6 for $n$ odd., Comment: 11 pages

Published
2017

8. $ B_c B_c J/\psi $ Vertex Form Factor at Finite Temperature in the Framework of QCD Sum Rules Approach

Author

Yazici, E., Sundu, H., and Veliev, E. Veli

Subjects
High Energy Physics - Phenomenology
Abstract

The strong form factor of the $B_{c} B_{c}J/\Psi$ vertex is calculated in the framework of the QCD sum rules method at finite temperature. Taking into account additional operators appearing at finite temperature, thermal Wilson expansion is obtained and QCD sum rules are derived. While increasing temperature, the strong form factor remains unchanged up to $T\simeq100~MeV$ but slightly increases after this point. After $T\simeq160~MeV$, the form factor suddenly decreases up to $T\simeq170~MeV$. The obtained result of the coupling constant by fitting the form factor at $Q^2=-m^2_{offshell}$ at $T=0$ is in a very good agreement with the QCD sum rules calculations at vacuum. Our prediction can be checked in the future experiments., Comment: 8 pages, 7 figures

Published
2015
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9. Uniformly resolvable $(C_4, K_{1,3})$-designs of order $v$ and index $2$

Author

Gionfriddo, M., Kucukcifci, S., Milici, S., and Yazici, E. S.

Subjects
Mathematics - Combinatorics, 05C51, 05C38, 05C70
Abstract

In this paper we consider the uniformly resolvable decompositions of the complete graph $2K_v$ into subgraphs where each resolution class contains only blocks isomorphic to the same graph. We completely determine the spectrum for the cases in which all the resolution classes are either $C_4$ or $K_{1,3}$., Comment: arXiv admin note: text overlap with arXiv:1402.4603

Published
2015

10. Thermal behaviors of light unflavored tensor mesons in the framework of QCD sum rule

Author

Azizi, K., Turkan, A., Sundu, H., Veliev, E. Veli, and Yazici, E.

Subjects
High Energy Physics - Phenomenology
Abstract

In this study, we investigate the sensitivity of the masses and decay constants of the light $f_{2}(1270)$ and $a_{2}(1320)$ tensor mesons to the temperature using QCD sum rule approach. In our calculations, we take into account the additional operators appearing in operator product expansion at finite temperature. It is obtained that at deconfinement temperature the decay constants and masses decrease with amount of $6\%$ and $96\%$ compared to their vacuum values, respectively. Our results on the masses at zero temperature are consistent with the vacuum sum rules predictions as well as the experimental data., Comment: 4 Pages and 1 Table, Prepared for the proceeding of the 4th International Conference on Hadron Physics (TROIA'14)

Published
2015
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11. Investigation of the $D^{\ast}_{s}D_{s} \eta^{(\prime)}$ and $B^{\ast}_{s}B_{s} \eta^{(\prime)}$ vertices via QCD sum rules

Author

Yazici, E., Veliev, E. Veli, Azizi, K., and Sundu, H.

Subjects
High Energy Physics - Phenomenology
Abstract

The strong coupling constants among mesons are very important quantities as they can provide useful information on the nature of strong interaction among hadrons as well as the QCD vacuum. In this article, we investigate the strong vertices of the $D^{\ast}_{s}D_{s} \eta^{(\prime)}$ and $B^{\ast}_{s}B_{s} \eta^{(\prime)}$ in the framework of the QCD sum rule approach choosing the $\eta$ or $D_{s} (B_{s})$ meson as an off-shell state. We obtain the results $g_{D_s^*D_s\eta}=(1.46\pm 0.30)GeV^{-1}$, $g_{D_s^*D_s\eta^{\prime}}=(0.74\pm 0.16)GeV^{-1}$, $g_{B_s^*B_s\eta}=(5.29\pm 1.06)GeV^{-1}$ and $g_{B_s^*B_s\eta^{\prime}}=(2.29\pm 0.48)GeV^{-1}$ for the strong coupling constants under consideration, which can be checked in future experiments., Comment: 11 Pages, 4 Figures and 3 Tables

Published
2013

12. A polynomial embedding of pairs of orthogonal partial latin squares

Author

Donovan, D. and Yazıcı, E. Ş.

Subjects
Mathematics - Combinatorics
Abstract

We show that a pair of orthogonal partial latin squares of order $n$ can be embedded in a pair of orthogonal latin squares of order at most $16n^4$ and all orders greater than or equal to $48n^4$. This paper provides the first direct polynomial order embedding construction in the literature.

Published
2013

13. Atrial natriuretic peptide and posterior pituitary neurohormone changes in patients with acute schizophrenia

Author

Guzel D, Yazici AB, Mutu Pek T, Doganay S, Saykan Simsek AB, Saglam K, Turan C, and Yazici E

Subjects
schizophrenia, oxytocin, PANS, GAF, CGI, AVP, Neurosciences. Biological psychiatry. Neuropsychiatry, RC321-571, Neurology. Diseases of the nervous system, RC346-429
Abstract

Derya Guzel,1 Ahmet Bulent Yazici,2 Tugba Mutu Pek,2 Songul Doganay,1 Alime Burcin Saykan Simsek,2 Kadir Saglam,1 Caglar Turan,2 Esra Yazici2 1Department of Physiology, School of Medicine, Sakarya University, Sakarya, Turkey; 2Department of Psychiatry, School of Medicine, Sakarya University, Sakarya, Turkey Objectives: Interactions between neuropeptides and psychiatric disorders have been investigated for many years. The aim of this study was to evaluate oxytocin (OXT), arginine-vasopressin (AVP), and atrial natriuretic peptide (ANP) and assess their interactions with each other, as well as investigate these changes with the manifestations of schizophrenia. Participants and methods: Thirty-four individuals having acute schizophrenia and 24 healthy individuals as the control group were included in the study. Positive and Negative Syndrome Scales, Global Assessment of Functionality score, and Clinical Global Impression (CGI) scores were measured. Serum hormone levels were analyzed using enzyme-linked immunosorbent assay and were compared with the clinical findings. Results: OXT levels were significantly lower and AVP levels were significantly higher in patients having acute schizophrenia than the control group. OXT was negatively correlated with Positive and Negative Syndrome Scales positive score and CGI score, while it was positively correlated with Global Assessment of Functionality score. AVP was negatively correlated with CGI score. ANP levels of the patients having schizophrenia were lower than the control group; however, there was no significant correlation with clinical findings. Conclusion: The obtained data indicate that the AVP level was higher, but OXT and ANP levels were lower in the patients having acute schizophrenia. Specifically OXT is related with reduced disease severity and increased functionality. Keywords: schizophrenia, oxytocin, PANS, GAF, CGI, AVP

Published
2018

15. Smoking, alcohol, and substance use and rates of quitting during pregnancy: is it hard to quit?

Author

Yazici AB, Uslu Yuvaci H, Yazici E, Halimoglu Caliskan E, Cevrioglu AS, and Erol A

Subjects
pregnancy, substance, smoking, alcohol, cannabinoids, Gynecology and obstetrics, RG1-991
Abstract

Ahmet Bulent Yazici,1 Hilal Uslu Yuvaci,2 Esra Yazici,3 Ebru Halimoglu Caliskan,4 Arif Serhan Cevrioglu,2 Atila Erol3 1Department of Psychiatry, Training and Research Hospital, 2Faculty of Medicine, Department of Obstetrics and Gynaecology, 3Faculty of Medicine, Department of Psychiatry, 4Department of Obstetrics and Gynaecology, Training and Research Hospital, Sakarya University, Sakarya, Turkey Background: Alcohol and substance use is a major health challenge in Turkey, as it is worldwide. Recently, there has been a rapid increase in the number of females using substances and although usage tends to reduce during pregnancy, it is of critical importance to determine its exact level as substance use negatively impacts on the health of both the mother and infant. Aim: The aim of the present study was to investigate the frequency of smoking, alcohol, and substance use, and quitting rates during pregnancy. Method: This study was conducted on pregnant females in Sakarya, Turkey. A total of 1,082 consecutively presenting females who agreed to participate in the study were evaluated. The study team prepared a sociodemographic data form and adapted the “Introduction” section, derived from the Addiction Profile Index, to cover substance use during pregnancy. Results: The substances most frequently used by pregnant females in their previous pregnancies and current pregnancies were cigarettes/tobacco products (11% and 11.8%, respectively), alcohol (0.6% and 0.4%, respectively), and rarely, synthetic cannabinoids (0.3% and 0.2%, respectively). Daily tobacco smokers continued to smoke during pregnancy, with a rate of 42.5%. Based on research into predictors of smoking (cigarettes) in pregnancy, a correlation was found between lifetime smoking and smoking during a previous pregnancy. A similar link was found with respect to alcohol. Conclusion: Cigarettes are the most frequently used substance in pregnancy, and to a lesser extent, alcohol and synthetic cannabinoids, also considered to be risky substances. A high incidence of smoking regularly during pregnancy was found in daily smokers. It is recommended that physicians should sensitively ask pregnant females presenting at clinics about all forms of substance use, including alcohol and synthetic cannabinoids, and to include such questions in their routine enquiries. Keywords: perinatal, psychiatry, addiction, cessation, women, mental, health

Published
2016

17. The Anthroscape Approach in Sustainable Land Use

Author

Eswaran, H., Berberoğlu, S., Cangir, C., Boyraz, D., Zucca, C., Özevren, E., Yazıcı, E., Zdruli, P., Dingil, M., Dönmez, C., Akça, E., Çelik, I., Watanabe, T., Koca, Y. K., Montanarella, L., Cherlet, M., Kapur, S., Kapur, Selim, editor, Eswaran, Hari, editor, and Blum, Winfried E.H., editor

Published
2011
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19. Addiction profile in probation practices in Turkey: 5-year data analysis

Author

Yazici AB, Yazici E, Akkisi Kumsar N, and Erol A

Subjects
Neurosciences. Biological psychiatry. Neuropsychiatry, RC321-571, Neurology. Diseases of the nervous system, RC346-429
Abstract

Ahmet Bülent Yazici,1 Esra Yazici,2 Neslihan Akkisi Kumsar,1 Atila Erol2 1Department of Psychiatry, Sakarya University Training and Research Hospital, 2Department of Psychiatry, Sakarya University Faculty of Medicine, Sakarya, Turkey Introduction: While drug addiction is a global problem, it is important for every region to know the general features of its own addicts in order to develop effective treatment programs. This study presents sociodemographic data of the individuals diagnosed with drug addiction.Methods: In this study, data of the patients between the years of 2009 and 2014 were retrospectively analyzed. The patients were assessed at psychiatry polyclinics according to probation practices of drug abuse. The study involved 513 patients in whom drug positivity was detected in urine analysis at least once and whose diagnoses were confirmed with a clinical interview.Results: According to this study, a majority of the addicts were detected in 2013. Males made up 98.2% of the sample population, their average age was 32.12±10.21 years, and minimum and maximum ages for the first drug use were 7 years and 45 years, respectively. Marijuana use was found in 90.8% of the patients, 90% of them were living with their families, and 59.6% of them held a regular job. Treatment response was related with age of first use of drugs, duration of use drugs, and prior treatment anamnesis of the patients.Conclusion: In this study, it was determined that the drug which was most frequently was used marijuana. The risk of drug addiction can affect any individual in society, regardless of their education, occupation, or social support levels. Alternative treatment models, especially for chronic and long-term users, should be researched. Keywords: addiction, crime, cannabis, substance use

Published
2015

20. Untreated depression in the first trimester of pregnancy leads to postpartum depression: high rates from a natural follow-up study

Author

Yazici E, Kirkan TS, Aslan PA, Aydin N, and Yazici AB

Subjects
Neurosciences. Biological psychiatry. Neuropsychiatry, RC321-571, Neurology. Diseases of the nervous system, RC346-429
Abstract

Esra Yazici,1 Tulay Sati Kirkan,2 Puren Akcali Aslan,3 Nazan Aydin,4 Ahmet Bulent Yazici1 1Department of Psychiatry, Faculty of Medicine, Sakarya University, Adapazari, Turkey; 2Bolge Training and Research Hospital, Erzurum, Turkey; 3Adana Training and Research Hospital, Adana, Turkey; 4Bakirkoy Nervous and Mental Disease Education and Research Hospital, Istanbul, Turkey Background: This is a natural follow-up study that presents the postpartum results of women who experienced depression during pregnancy. Methods: This study involved 78 women diagnosed with depression in the first trimester of pregnancy. All patients were diagnosed using the Structured Clinical Interview for DSM-IV Axis I Disorders (SCID-I) in the first trimester and all were referred to a psychiatric center for treatment. Of the 78, 73 were contacted postpartum and reassessed by SCID-I. Treatment anamnesis was evaluated retrospectively. Results: The women were divided into two groups at the postpartum evaluation according to anamnesis of psychiatric treatment. Twenty-one of the 73 (28.7%) had received treatment during pregnancy (treated group). Fifty-two women had not been treated (untreated group). In the treated group, no postpartum depression was determined (0%). In the untreated group, 92% (n=48) of women had a depressive disorder postpartum (P

Published
2015

21. Motivation for treatment in patients with substance use disorder: personal volunteering versus legal/familial enforcement

Author

Bilici R, Yazici E, Tufan AE, Mutlu E, İzci F, and Ugurlu GK

Subjects
Neurosciences. Biological psychiatry. Neuropsychiatry, RC321-571, Neurology. Diseases of the nervous system, RC346-429
Abstract

Rabia Bilici,1 Esra Yazici,2 Ali Evren Tufan,3 Elif Mutlu,4 Filiz İzci,1 Görkem Karakas Ugurlu5 1Erenkoy Mental Health and Neurology Training and Research Hospital, Department of Psychiatry, Istanbul; 2Sakarya University, Medical Faculty, Department of Psychiatry, Sakarya, 3Abant Izzet Baysal University, Medical Faculty, Department of Child and Adolescent Psychiatry, Bolu, 4Bakirköy Mental Health and Neurology Training and Research Hospital, Department of Psychiatry, Istanbul, 5Yildirim Beyazit University, Medical Faculty, Department of Psychiatry, Ankara, Turkey Background: Motivation for treatment on the part of patients with addictive disorders is known to affect their prognosis, and lack thereof is reported to be among the most common reasons for failed treatment adherence and relapse after treatment. This study evaluated the relationship between volunteering, personality, demographic factors, and motivation for treatment. Methods: The study was conducted at a substance dependence center in the eastern part of Turkey. Forty-five patients (mean age 37.9±11.2 years) with a substance use disorder were included. They were assessed using the Structured Clinical Interview for DSM (Diagnostic and Statistical Manual of Mental Disorders) Axis II disorders. Depression and anxiety were evaluated using the Beck depression and anxiety inventories, and motivation for treatment was measured using the Turkish version of the Texas Christian University Motivation for Treatment scale. Results: All patients had been using substances daily and 41 (88.9%) had been using multiple drugs. The most commonly used substance was heroin (n=18, 40%). Voluntary admission was a predictor of motivation for treatment (P

Published
2014

22. The Effects of Formalism on Teacher Trainees' Algebraic and Geometric Interpretation of the Notions of Linear Dependency/Independency

Author

Ertekin, E., Solak, S., and Yazici, E.

Abstract

The aim of this study is to identify the effects of formalism in teaching on primary and secondary school mathematics teacher trainees' algebraic and geometric interpretations of the notions of linear dependency/independency. Quantitative research methods are drawn in order to determine differences in success levels between algebraic and geometric interpretations of the linear dependency/independency of vectors presented in two- and three-dimensional space. On the other hand, qualitative research methods were utilized in order to investigate thinking modes involved in the geometric interpretation of the same notion. The participants were a total of 144 teacher trainees registered at the Selcuk University, Education Faculty in 2007-2008 academic year. 33 participants were first year students at Secondary Mathematics Education Department, while 111 were second year students at Primary Mathematics Education Department. The results indicated that correlations between the formal definition of the notions of linear dependency/independency and the items of the test which required algebraic and geometric interpretation were both low. Yet, the correlation for the algebraic dimension of the test was higher than the geometric dimension. Likewise, algebraic mean success score was significantly higher than the geometric mean score. (Contains 9 tables and 7 figures.)

Published
2010
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23. Smoking, alcohol, and substance use and rates of quitting during pregnancy: is it hard to quit?

Author

Esra Yazici, Uslu Yuvaci H, Yazici E, Halimoglu Caliskan E, As, Cevrioglu, and Erol A

Subjects
cannabinoids, alcohol, pregnancy, substance, lcsh:Gynecology and obstetrics, smoking, lcsh:RG1-991
Abstract

Ahmet Bulent Yazici,1 Hilal Uslu Yuvaci,2 Esra Yazici,3 Ebru Halimoglu Caliskan,4 Arif Serhan Cevrioglu,2 Atila Erol3 1Department of Psychiatry, Training and Research Hospital, 2Faculty of Medicine, Department of Obstetrics and Gynaecology, 3Faculty of Medicine, Department of Psychiatry, 4Department of Obstetrics and Gynaecology, Training and Research Hospital, Sakarya University, Sakarya,Turkey Background: Alcohol and substance use is a major health challenge in Turkey, as it is worldwide. Recently, there has been a rapid increase in the number of females using substances and although usage tends to reduce during pregnancy, it is of critical importance to determine its exact level as substance use negatively impacts on the health of both the mother and infant. Aim: The aim of the present study was to investigate the frequency of smoking, alcohol, and substance use, and quitting rates during pregnancy. Method: This study was conducted on pregnant females in Sakarya, Turkey. A total of 1,082 consecutively presenting females who agreed to participate in the study were evaluated. The study team prepared a sociodemographic data form and adapted the “Introduction” section, derived from the Addiction Profile Index, to cover substance use during pregnancy. Results: The substances most frequently used by pregnant females in their previous pregnancies and current pregnancies were cigarettes/tobacco products (11% and 11.8%, respectively), alcohol (0.6% and 0.4%, respectively), and rarely, synthetic cannabinoids (0.3% and 0.2%, respectively). Daily tobacco smokers continued to smoke during pregnancy, with a rate of 42.5%. Based on research into predictors of smoking (cigarettes) in pregnancy, a correlation was found between lifetime smoking and smoking during a previous pregnancy. A similar link was found with respect to alcohol. Conclusion: Cigarettes are the most frequently used substance in pregnancy, and to a lesser extent, alcohol and synthetic cannabinoids, also considered to be risky substances. A high incidence of smoking regularly during pregnancy was found in daily smokers. It is recommended that physicians should sensitively ask pregnant females presenting at clinics about all forms of substance use, including alcohol and synthetic cannabinoids, and to include such questions in their routine enquiries. Keywords: perinatal, psychiatry, addiction, cessation, women, mental, health

Published
2016

25. a New Imidazole-based Ligand

Author

Yazici, E, Firat, M, Chormey, DS, Budak, TB, Sahin, C, Turak, F, and Bakirdere, S

Abstract

This study presents a sensitive, accurate, and precise analytical method for the determination of cadmium in water samples. A laboratory synthesized imidazole-based ligand (2-(4-methylphenyl)1H-imidazo-[4,5-f]-[1,10]-phenanthroline) was used to form a cadmium complex for extraction by dispersive liquid-liquid microextraction (DLLM). Optimization of complexation, extraction, and instrumental parameters led to a 74-fold enhancement in the detection power of FAAS. The limits of detection and quantification were found at 0.57 and 1.9 mu g/L, respectively. The relative standard deviation of the method was less than 5.0%, indicating high precision for the experimental process. Accuracy and applicability of the method were tested on environmental (tap, well, and wastewater) and drink (rose hip tea) samples at different spiking concentrations, and satisfactory recovery results were obtained between 88 and 112%. C1 [Yazici, Elif; Firat, Merve; Chormey, Dotse Selali; Budak, Turkan Borklu; Turak, Fatma; Bakirdere, Sezgin] Yildiz Tech Univ, Dept Chem, TR-34349 Istanbul, Turkey. [Sahin, Cigdem] Pamukkale Univ, Fac Art & Sci, Chem Dept, TR-20070 Denizli, Turkey.

Published
2019

26. Uniformly resolvable $(C_4, K_{1,3})$-designs of order v and

Author

Gionfriddo, Mario, Kucukcifci, Selda, Milici, Salvatore, and Sule Yazici, E

Subjects
Design Theory, Resolvable graph decomposition, Uniform resolutions
Abstract

In this paper we consider the uniformly resolvable decompositions of the complete graph $\lambda K_v$ into subgraphs where each resolution class contains only blocks isomorphic to the same graph. We consider the cases in which all the resolution classes are either $C_4$ or $K_{1,3}$. We prove that this type of system does not exist for $\lambda$ odd and determine completely the spectrum for $\lambda=2$., Contributions to Discrete Mathematics, Vol 13, No 1 (2018)

Published
2018
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28. Total oxidant and antioxidant activities in milk with various somatic cell count intervals during discrete cow and buffalo lactation periods

Author

Yigit, A. A., Cinar, M., Macun, H. C., Ozenc, E., Kabakci, R., Yazici, E., Salar, S., and Kırıkkale Üniversitesi

Subjects
stomatognathic diseases, Total oxidant, Cow milk, food and beverages, Lactation number, Buffalo milk, Total antioxidant
Abstract

YAZICI, Ebubekir/0000-0002-1219-4370; KABAKCI, Ruhi/0000-0001-9131-0933 WOS: 000426365000012 This study first investigated the total oxidant and antioxidant capacity (TOC and TAC, respectively) in cow and buffalo milk, with various somatic cell count (SCC) levels, having the same lactation numbers(LN). Second, it determined whether there is an association between the TAC and TOC and the lactation number, for the same SCC level. Quarter milk samples, collected from Holstein cows and Anatolian buffaloes, were separated into SCC levels of = 1x10(6) cells mL(-1) for cow milk, and = 1x10(6) cells mL(-1), for buffalo milk. Next, each group was subdivided, according to the lactation number (cows: 1-2nd, 3-4th, 5-6th, buffaloes: 1-4th, 5-8th, 9-12th), and TOC and TAC of the milk were measured. For the same lactation numbers, TOC increased in the cow and buffalo groups with an SCCV >= 1x10(6) cells mL(-1) (p< 0.05). Conversely, TAC decreased in cow milk with an SCC > 5x10(5)cells mL(-1). In buffalo milk, TAC decreased in parallel with the increased SCC. Among the same SCC groups, TOC and TAC were not affected by the lactation number, in cow and buffalo milk. An increased SCC caused an increased TOC and decreased TAC level, for the same lactation number. No relation existed among TOC, TAC and lactation number, for the same SCC level. SCC may be used as an indicator of TOC and TAC in cow and buffalo milk. Kirikkale UniversityKirikkale University [2014/120] This study was supported by the Kirikkale University Scientific Research Project Coordination Unit: 2014/120.

Published
2018

29. Estimates Of The Coverage Of Parameter Space By Latin Hypercube And Orthogonal Array-Based Sampling

Author

Donovan, D., Burrage, K., Burrage, P., McCourt, T. A., Thompson, B., and Yazici, E. S.

Abstract

In this paper we use counting arguments to prove that the expected percentage coverage of a d dimensional parameter space of size n when performing k trials with either Latin Hypercube sampling or Orthogonal Array-based Latin Hypercube sampling is the same. We then extend these results to an experimental design setting by projecting onto a t < d dimensional subspace. These results are confirmed by simulations. The theory presented has both theoretical and practical significance in modelling and simulation science when sampling over high dimensional spaces. (C) 2017 Elsevier Inc. All rights reserved.

Published
2018

30. Recovery Of Silver From Cyanide Leach Solutions By Precipitation Using Trimercapto-S-Triazine (Tmt)

Author

Yazici, E. Y., Yilmaz, E., Ahlatci, F., Celep, O., and Deveci, H.

Abstract

Cyanide leaching is the most common method used for production of silver from gold/silver ores. Silver (and gold) can be recovered from pregnant leach solutions (PLSs) using Merrill-Crowe process (zinc cementation) and activated carbon adsorption. Due to their inherent limitations and paucity of selectivity, development of alternative processes for selective recovery of silver from PLSs is of great interest. In the current study, selective recovery of silver by precipitation from cyanide solutions using an environmentally friendly organic reagent i.e. Trimercapto-s-triazine (C3N3S3; TMT) was investigated. The results have shown that precipitation of silver by TMT is a rapid process in that 87.9% of silver could be precipitated at the initial period of 5 min. Response surface methodology (i.e. central composite design) was adopted to examine the main and interaction effects of [TMT]/[Ag] ratio (0.09-36.52), [CN]/[Ag] ratio (3-10) and initial concentration of silver (1-40 mg/L Ag) on the precipitation of silver in five levels. The statistical analysis of the experimental data revealed that ratio of [TMT]/[Ag] (i.e. concentration of TMT) was the key parameter exerting a profound effect on the precipitation of silver. However, effects of [CN]/[Ag] ratio and Ag concentration appeared to be statistically insignificant. Complete precipitation of silver was found to be readily achieved under suitable conditions. The precipitation process was proved to be highly selective for silver over gold and copper as also confirmed by the tests on real pregnant leach solutions. It was found that the presence of TMT had no discernible effect on adsorption of gold by activated carbon, which was observed to even improve from copper containing solutions. Silver-TMT precipitates were characterised using SEM/EDS, FT-IR and other techniques. The current findings demonstrate that this precipitation process can be exploited as a potent alternative for selective recovery of silver from cyanide leach solutions of silver and gold/silver ores or purified/concentrated solutions ahead of gold electro-winning.

Published
2017

31. An investigation for people with mental disorders regarding their learning-recalling-pronunciation of medicine brand names [Ruhsal hastalığı olan bireylerin kullandıkları ilaç adlarını öğrenme-anımsama-sesletim durumu açisından incelenmesi]

Author

Yildiz M., Boşgelmez Ş., Çakir U., Yazici A.B., Turgut C., Yazici E., Ay B., İstanbul Arel Üniversitesi, Yildiz, M., KOÜ Hastalıkları ABD, İzmit, Turkey, Boşgelmez, Ş., Derince Eğitim Araştırma Hastanesi, Ruh Sağlığı ve Hastalıkları Bölümü, İzmit, Turkey, Çakir, U., Derince Eğitim Araştırma Hastanesi, Ruh Sağlığı ve Hastalıkları Bölümü, İzmit, Turkey, Yazici, A.B., İzmit Seka Devlet Hastanesi, Ruh Sağlığı ve Hastalıkları Bölümü, İzmit, Turkey, Turgut, C., KOÜ Hastalıkları ABD, İzmit, Turkey, Yazici, E., Derince Eğitim Araştırma Hastanesi, Ruh Sağlığı ve Hastalıkları Bölümü, İzmit, Turkey, and Ay, B., Arel Üniversitesi Psikoloji Yüksek Lisans Öğrencisi, İstanbul, Turkey

Subjects
Psychiatric patients, Recalling, Pronunciation, Labeling, Learning, Medicine brand name, Turkish language
Abstract

Objective: In the field of mental health it is not rare to encounter that patients have difficulties in learning, re-calling and pronouncing brand names of their medicines. In this study it was aimed to determine the problems of psychiatric outpatients in recalling and pronouncing brand names of their medicines.Methods: Patients from four psychiatric outpatient clinics were questioned about the brand names of their medicines. Response scores were standardized as: One point: accurately recalled and accurately pronounced. Two points: accurately recalled, but inaccurately pronounced. Three points: recalled with assistance (by given clue) and accurately pronounced. Four points: recalled with assistance (by given clue), but inaccurately pronounced. Five points: Not recalled at all. Correlations between scores and educational level, age and duration of the medicine usage were examined.Results: Eight hundred and forty-eight patients were enrolled to the study. All patients gave verbal informant consent. Most of the participants were female, married and unemployed. Mean age was 40 and mean level of education was eight years. Fifty-six percent of patients have accurately recalled and pronounced (those scored 1 point) brand name of at least one medicine they are taking, but 30% of patients inaccurately recalled and pronounced their medicines. While Zestat, Dideral, Clonex, Akineton and Depakin were brand names those more accurately recalled and accurately pronounced, Xetanor, Wellbutrin, Tegretol, Desyrel and Redepra were brand names those most difficultly recalled and pronounced. No important correlation between scores and level of education, age and duration of the medicine usage has been found. Conclusion: Results of this study address a serious problem about to recall and pronouncing of brand names of medicines those are used in mental health field. In regard to learning and recalling of the words easily, it is necessary to have an association between the phonetic, auditory and meaningful association of the words. Brand names those have familiar association for the patient were easily recalled and pronounced. This study refers to the importance of starting to consider what to do about substituting brand names of drugs with those are more compatible with Turkish language in order to recall and pronounce the medicine names easily and accurately for patients speaking Turkish. © 2014 Cukurova University, Faculty of Medicine. All rights reserved.

Published
2014

32. BcBcJ/ψ vertex form factor at finite temperature in the framework of QCD sum rules approach

Author

Yazici, E., Sundu, H., and Veliev, E. Veli

Abstract

The strong form factor of the BcBcJ/Ψ vertex is calculated in the framework of the QCD sum rules method at finite temperature. Taking into account additional operators appearing at finite temperature, a thermal Wilson expansion is obtained and QCD sum rules are derived. While increasing the temperature, the strong form factor remains unchanged up to T≃100MeV but slightly increases after this point. After T≃160MeV , the form factor suddenly decreases up to T≃170MeV . The obtained result of the coupling constant by fitting the form factor at Q2=-moffshell2 at T=0 is in a very good agreement with the QCD sum rules calculations in the case of vacuum. Our prediction can be checked in future experiments.

Published
2016

33. $ B_c B_c J/��$ Vertex Form Factor at Finite Temperature in the Framework of QCD Sum Rules Approach

Author

Yazici, E., Sundu, H., and Veliev, E. Veli

Subjects
High Energy Physics - Phenomenology (hep-ph), FOS: Physical sciences
Abstract

The strong form factor of the $B_{c} B_{c}J/��$ vertex is calculated in the framework of the QCD sum rules method at finite temperature. Taking into account additional operators appearing at finite temperature, thermal Wilson expansion is obtained and QCD sum rules are derived. While increasing temperature, the strong form factor remains unchanged up to $T\simeq100~MeV$ but slightly increases after this point. After $T\simeq160~MeV$, the form factor suddenly decreases up to $T\simeq170~MeV$. The obtained result of the coupling constant by fitting the form factor at $Q^2=-m^2_{offshell}$ at $T=0$ is in a very good agreement with the QCD sum rules calculations at vacuum. Our prediction can be checked in the future experiments., 8 pages, 7 figures

Published
2015
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34. Treatment Of Copper-Rich Gold Ore By Cyanide Leaching, Ammonia Pretreatment And Ammoniacal Cyanide Leaching

Author

Bas, A. D., Koc, E., Yazici, E. Y., and Deveci, H.

Subjects
inorganic chemicals, technology, industry, and agriculture
Abstract

The treatment of a copper sulphide-bearing gold ore by direct cyanide leaching, ammonia pretreatment and ammoniacal cyanide leaching was investigated. Dissolution behaviour of gold and copper in these leaching systems was demonstrated. Severe interference by the copper containing sulphides with cyanide leaching of gold is observed at rho(NaCN)

Published
2015

35. Cupric Chloride Leaching (Hcl-Cucl2-Nacl) Of Metals From Waste Printed Circuit Boards (Wpcbs)

Author

Yazici, E. Y. and Deveci, H.

Abstract

The leaching of metals from waste printed circuit boards (WPCBs) in cupric chloride solutions (HCl-CuCl2-NaCl) was studied. Effects of initial concentration of cupric (8-157 mM Cu2+), chloride (0.7-2.0 M NaCl), temperature (20-80 degrees C), solids ratio (1-15 w/v) and air/oxygen (1 L/min) on the leaching of copper as well as other metals (i.e. Fe, Ni, Ag, Pd and Au) were investigated. The findings have shown that increasing the initial concentration of Cu2+ leads to a significant enhancement in the metal extractions. At Cu2+ concentrations of >= 79 mM, high extractions (i.e. >= 98%) for copper, nickel and iron were obtained over 120 min. An increase in the concentration of chloride (i.e. from 0.7 M to 2 M Cl-) decreased the extraction of copper by up to 40% at 60 min due to the decrease in the activity of free Cu2+. Rising the temperature from 20 degrees C to 80 degrees C resulted in a 1.38-fold increase in the copper extraction at 120 min. The activation energy (E-a) for leaching of copper was calculated to be approximate to 41 kJ/mol, indicative of a chemically controlled leaching reaction. Air/oxygen (1 L/min) was supplied for the regeneration of Cu2+, which improved the extraction of all the metals monitored. Increasing the solids ratio (1-15 w/v) adversely affected the leaching process with no copper extraction at 15 w/v. However, the extraction of metals (Cu, Ni, Ag and Pd) substantially ameliorated in the presence of oxygen. The current study have shown that copper, palladium, nickel and silver can be readily extracted from WPCBs in cupric chloride leaching where the extraction of gold is very limited. (C) 2014 Elsevier B.V. All rights reserved.

Published
2015

36. A validity and reliability study of Grasha-Riechmann student learning style scale

Author

Baykul, Y., Gürsel, M., Sulak, H., Ertekin, E., Yazici, E., Dülger, O., Büyükkarci, K., Çukurova Üniversitesi, Baykul, Y., Gürsel, M., Sulak, H., Ertekin, E., Yazici, E., Dülger, O., Büyükkarci, K., and Yeditepe Üniversitesi

Subjects
Grasha-Riechmann, Learning styles, Reliability, Validity
Abstract

The reliability of the tools developed to learn the learning styles is essential to find out students' learning styles trustworthily. For this purpose, the psychometric features of Grasha- Riechman Student Learning Style Inventory developed by Grasha was studied to contribute to this field. The study was carried out on 6th, 7th, and 8th graders of 10 primary education schools in Konya. The inventory was applied twice with an interval of one month, and according to the data of this application, the reliability coefficient numbers of the 6 sub-dimensions pointed in the theory of the inventory was found to be medium. Besides, it was found that the inventory does not have a structure with 6 factors for both Mathematics and English courses as represented in the theory.

Published
2009

38. Ferric Sulphate Leaching Of Metals From Waste Printed Circuit Boards

Author

Yazici, E. Y. and Deveci, H.

Abstract

Leaching of copper and other metals (i.e., Ni, Ag and Pd) from waste printed circuit boards (WPCBs) in acidic ferric sulphate solutions was studied. The effects of concentration of H2SO4 (0.05-1 M), Fe(III) (0.05-0.5 M) and temperature (20-80 degrees C) on the extent and kinetics of extraction of metals were investigated using response surface methodology. Under the suitable conditions, high extractions of copper (i.e., >= 98%) were readily achieved over a leaching period of 120 min. The kinetic data derived from the shrinking particle model for copper were used as the response for the analysis of data. All the leaching parameters were statistically significant within an order of temperature > [Fe(III)] > [H2SO4] and increasing their levels had positive influence on the leaching kinetics. The activation energy for extraction of copper was found to be 18.3 kJ/mol. In addition to copper, nickel extractions were also high (i.e., up to 92.5% over 120 min) whilst silver and palladium extractions were limited to = 99% Ag/Pd) over 120 min. These findings suggest that acidic ferric sulphate solutions can be suitably used as a potent lixiviant system for the extraction of metals from WEEE. (C) 2014 Elsevier B.V. All rights reserved.

Published
2014

39. Extraction Of Metals From Waste Printed Circuit Boards (Wpcbs) In H2So4-Cuso4-Nacl Solutions

Author

Yazici, E. Y. and Deveci, H.

Abstract

The extraction of metals from waste printed circuit boards (WPCBs) in H2SO4-CuSO4-NaCl leaching system was studied. The effect of initial concentration of cupric (0.5-7.5 g/L Cu2+), chloride (4.7-46.6 g/L Cl-) and temperature (20-80 degrees C) on the leaching of copper was investigated using response surface methodology, i.e., three-level Box-Behnken design. Extraction of other metals including Fe, Ni, Ag, Pd and Au was also determined. The importance of the main effects of the leaching parameters on the extraction of copper was found to be in the decreasing order of temperature, the initial concentration of Cu2+ and Cl-. The findings have shown that the initial Cl-/Cu2+ molar ratio should be maintained sufficiently high to maximise extraction of copper. However, an excessively high Cl-/Cu2+ ratio can exert a detrimental effect on the process due to a decrease in the activity of Cu2+ as oxidant. It was found that the highest levels of all the parameters should be selected to achieve high leaching recoveries (>= 91%) for Cu, Fe, Ni and Ag. Under these conditions, the dissolution of palladium was limited to 58%. The effect of solids ratio (1-15% w/v) and air/oxygen (2-4 L/min) on the rate and extent of leaching were also tested. Increasing the solids ratio (1-15 w/v) was observed to adversely affect the leaching of metals with no copper extraction at 10 w/v in the absence of air/oxygen. Air/oxygen was confirmed to be a suitable oxidant to regenerate Cu2+ and hence, maintain high Cu2+/Cu+ ratios, i.e., redox potentials during the leaching process. The presence of air/oxygen led to a significant improvement in the leaching of metals, e.g., %14 Cu (no air/oxygen) cf. complete copper extraction at >= 2 L/min air/oxygen over 120 min. The current findings suggested that, particularly at high solids ratios (>= 5% w/v), the regeneration of Cu2+ by the introduction of air/oxygen is essential for high extraction of metals, Pd in particular. (C) 2013 Elsevier B.V. All rights reserved.

Published
2013

40. Bioleaching Of Copper From Low Grade Scrap Tv Circuit Boards Using Mesophilic Bacteria

Author

Bas, A. D., Deveci, H., and Yazici, E. Y.

Abstract

In this study, the extraction of copper from manufacturing scrap TV circuit boards (STVB) by bacteria-assisted leaching was studied using a mixed culture of mesophilic bacteria. Initial availability of soluble iron appeared to be of prime importance for the extraction of copper from STVB, which contains 43 g/ton Fe. In this respect, the addition of 1-8 g/L Fe(II) significantly improved (by up to 54%) the extraction of copper from STVB at the expense of the increased acid consumption. A new approach for the bioleaching process was adopted, which is based on the addition of pyrite (5-50 g/L pyrite concentrate (PyC)) as a source of iron and sulphur. Copper extraction was observed to enhance from 24% to 84% in the presence of 50 g/L PyC with a significant decrease (62%) in the consumption of acid. An increase in the size of inoculum from 10% to 50% v/v was also observed to improve the bioleaching rate of copper. The findings in the current study highlight the practical importance of the availability of iron (and hence, iron content of wastes) for the successful development of a bioleaching process for e-waste and the potential for utilisation of pyrite as a suitable source of iron and sulphur in bioleaching of e-waste. (C) 2013 Elsevier B.V. All rights reserved.

Published
2013

43. Fruit quality and biochemical characterization of recently developed seedless lemon cultivars.

Author

Oluk, A. C., Unlu, M., Seday, U., Yazici, E., and Uzun, A.

Abstract

Copyright of Fruits is the property of International Society for Horticultural Science and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Published
2017
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46. Characterisation of computer printed circuit boards for hazardous properties and beneficiation studies.

Author

Yazici E., XXV International Mineral Processing Congress: IMPC 2010 Brisbane, Australia 06-Sep-1010-Sep-10, Akcil A., Alp I., Deveci H., Yazici R., Yazici E., XXV International Mineral Processing Congress: IMPC 2010 Brisbane, Australia 06-Sep-1010-Sep-10, Akcil A., Alp I., Deveci H., and Yazici R.

Abstract

Printed circuit boards (PCBs) were manually obtained from various makes of end-of-life computer and subjected to size reduction to -3.35 mm in two crushing stages. Size fractions were obtained by dry sieving and used to determine the liberation size of the metals. The Cu content of the PCBs was 15.5%. The PCBs were subjected to standard protocols including the US Environmental Agency toxicity characteristic leaching procedure (TCLP) and synthetic precipitation leaching procedure (SPLP) and the ASTM D-3987 and EN 12457-2 tests to simulate different environmental scenarios. The results showed that the PCBs could be classified as hazardous wastes on the basis of the Pb concentration obtained from TCLP tests. The PCB leachates could also be classified as highly polluted water with respect to the SPLP and ASTM D-3987 tests. The EN 12457-2 test results showed that the PCBs failed the criteria for waste acceptable for landfill because of the concentrations of Pb, Cu and Ba in the PCB leachates. The high metal content of the PCBs makes them valuable secondary resources and recovery of the metals can mitigate potential environmental problems., Printed circuit boards (PCBs) were manually obtained from various makes of end-of-life computer and subjected to size reduction to -3.35 mm in two crushing stages. Size fractions were obtained by dry sieving and used to determine the liberation size of the metals. The Cu content of the PCBs was 15.5%. The PCBs were subjected to standard protocols including the US Environmental Agency toxicity characteristic leaching procedure (TCLP) and synthetic precipitation leaching procedure (SPLP) and the ASTM D-3987 and EN 12457-2 tests to simulate different environmental scenarios. The results showed that the PCBs could be classified as hazardous wastes on the basis of the Pb concentration obtained from TCLP tests. The PCB leachates could also be classified as highly polluted water with respect to the SPLP and ASTM D-3987 tests. The EN 12457-2 test results showed that the PCBs failed the criteria for waste acceptable for landfill because of the concentrations of Pb, Cu and Ba in the PCB leachates. The high metal content of the PCBs makes them valuable secondary resources and recovery of the metals can mitigate potential environmental problems.

Published
2010

47. Removal of thiocyanate from solutions by precipitation.

Author

Yazici E., XXV International Mineral Processing Congress: IMPC 2010 Brisbane, Australia 06-Sep-1010-Sep-10, Deveci H., Ucuncu R., Yazici E., XXV International Mineral Processing Congress: IMPC 2010 Brisbane, Australia 06-Sep-1010-Sep-10, Deveci H., and Ucuncu R.

Abstract

Metallurgical processes such as Au and Ag leaching and metal finishing often produce effluents containing cyanide and cyanide-related compounds such as thiocyanate. The toxicity of thiocyanate is relatively low compared with hydrogen cyanide but it is still of environmental concern. The removal of thiocyanate from aqueous solutions by precipitation in the presence of sodium thiosulphate and Cu ions was studied using the Taguchi experimental design approach. The effects of thiocyanate concentration in the range 10-50 mg/l, Cu2+ concentrations of 10-50 mg/l, thiosulphate concentrations of 20-150 mg/l and pH in the range 4.5-10.5 on the extent of thiocyanate removal from synthetic solutions were investigated. Statistical evaluation of the data showed that thiosulphate concentration and pH had the greatest effect on thiocyanate precipitation. Removal of thiocyanate was adversely affected by increasing thiosulphate concentration, particularly at concentrations above 80 ppm. Acidic solutions at pH 4.5 and neutral solutions at pH 8.5 favoured thiocyanate precipitation while alkaline solutions at pH 10.5 had an adverse effect. The method is effective for the treatment of effluents containing thiocyanate, with no by-product generation., Metallurgical processes such as Au and Ag leaching and metal finishing often produce effluents containing cyanide and cyanide-related compounds such as thiocyanate. The toxicity of thiocyanate is relatively low compared with hydrogen cyanide but it is still of environmental concern. The removal of thiocyanate from aqueous solutions by precipitation in the presence of sodium thiosulphate and Cu ions was studied using the Taguchi experimental design approach. The effects of thiocyanate concentration in the range 10-50 mg/l, Cu2+ concentrations of 10-50 mg/l, thiosulphate concentrations of 20-150 mg/l and pH in the range 4.5-10.5 on the extent of thiocyanate removal from synthetic solutions were investigated. Statistical evaluation of the data showed that thiosulphate concentration and pH had the greatest effect on thiocyanate precipitation. Removal of thiocyanate was adversely affected by increasing thiosulphate concentration, particularly at concentrations above 80 ppm. Acidic solutions at pH 4.5 and neutral solutions at pH 8.5 favoured thiocyanate precipitation while alkaline solutions at pH 10.5 had an adverse effect. The method is effective for the treatment of effluents containing thiocyanate, with no by-product generation.

Published
2010

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