Numerical solution of second order linear hyperbolic telegraph equation

This paper is of about a numerical solution of the second order linear hyperbolic telegraph equation. To solve numerically the second order linear hyperbolic telegraph equation, the cubic B-spline collocation method is used in space discretization and the fourth order one-step method is used in time discretization. By using the fourth order one-step method, it is aimed to obtain a numerical algorithm whose accuracy is higher than the current studies. The efficiency and accuracy of the proposed method is studied by two examples. The obtained results show that the proposed method has higher accuracy as intended.This work has been supported by the Scientific Research Council of Eskisehir Osmangazi University under project No. 2018-2090.Publisher's Versio

YERALTI KÖMÜR MADENCİLİĞİNDE MEKANİZASYONUN İŞÇİ SAĞLIĞI VE İŞ GÜVENLİĞİ AÇISINDAN ÖNEMİ

Yeraltı kömür madenciliği, iş kazası riskinin çok yüksek olduğu, emek yoğunluğunun en yüksek ve en tehlikeli olduğu iş kollarından biridir. Ancak, kömür madenciliğinin yapıldığı birçok ülkede, insan gücü kullanılan yöntemlerin yerine, kömürün çıkartılıp yüklenmesi, artık makineler tarafından yapılmaktadır. Yeraltı kömür madenciliğinde kömür üretiminde pek çok çalışma disiplininin bir arada yürütülmesi söz konusudur. İşçi sağlığı ve iş güvenliği problemlerinin ortaya çıktığı temel faaliyet üretim sürecidir. Üretim süreci; kazı, tahkimat, nakliyat gibi ana faaliyetler ve çeşitli makine ve teçhizatın bakım onarım işi gibi diğer faaliyetlerden ibarettir. Bu işlemler yürütülürken çeşitli sağlık ve güvenlik sorunları ortaya çıkar. Yeraltı kömür işletmelerinde en çok yaşanan iş kazası türleri göçükler, tahkimat işlerindeki aksaklıklar, kömür vb. malzeme nakliyatı gibi kömür üretim sürecinde yaşanan kazalardır. Bu işlemlerin aynı anda yürütülmesi ve iş kazalarının en aza indirilmesi için merkezi kontrol birimi oluşturularak sevk ve idare edilmesi gerekmektedir. Bunun için de ülkemizde yeraltı kömür üretiminde mekanizasyon uygulamasına geçilmesi gerekmektedir

The bounds for the largest eigenvalues of Fibonacci-sum and Lucas-sum graphs

In this paper, we first get the degree of each point in Lucas-sum graph based on Lucas numbers. After that, we obtain lower and upper bounds for the largest eigenvalues λ and µ of the adjacency matrices of Fibonacci-sum and Lucas-sum graphs, respectively.Publisher's Versio

Revisiting stapled and handsewn loop ileostomy closures: a large retrospective series

OBJECTIVE: To compare the surgical outcomes of stapled and handsewn closures in loop ileostomies. METHODS: The data of 225 patients requiring loop ileostomies from 2002 to 2007 were retrospectively evaluated. The patients underwent partial small-bowel resections and either handsewn or stapled anastomoses for the ileostomy closures. They were followed up postoperatively with routine surgical examinations. RESULTS: The study group consisted of 124 men and 101 women with a mean age of 49.12 years. The ileostomy closure was performed with handsewn in 129 patients and with stapled in 96 patients. The mean time to the first postoperative flatus was 2.426 days in the handsewn group and 2.052 days in the stapled group (p <0.05). The mean time to the first postoperative defecation was 3.202 days in the handsewn group and 2.667 days in the stapled group (p <0.05). The mean duration of patient hospital stay was 8.581 days for the handsewn group and 6.063 days for the stapled group (p <0.05). CONCLUSIONS: Patients who underwent ileostomy closure with stapled recovered faster in the postoperative period and required shorter hospital stays than those whose closures were performed with handsewn. In our opinion, stapled should be considered the gold standard for loop ileostomy closure

Titanium versus Hydroxyapatite Prostheses: Comparison of Hearing and Anatomical Outcomes after Ossicular Chain Reconstruction

Objective:This study aimed to compare hearing and anatomical outcomes after ossicular chain reconstruction with titanium or hydroxyapatite prostheses.Methods:In this study, patients who underwent tympanoplasty and ossicular chain reconstruction with titanium or hydroxyapatite prostheses at a university hospital from January 2007 to February 2013 were retrospectively reviewed; they had a minimum follow-up period of 6 months. Patients were divided into 4 groups according to the type of prostheses. The surgical procedure, follow- up examinations, preoperative, and postoperative audiometry results were noted and evaluated for partial and total prostheses. The results were compared both for titanium and hydroxyapatite prostheses.Results:The study subjects included 51 patients. Titanium had better hearing results in partial prostheses (p0.05). The extrusion rate was 5.8% for all patients.Conclusion:Both types of prostheses had satisfactory functional and anatomical results and no preponderance could be stated, except for the hearing results of partial titanium prostheses

Synthesis and Thermal Characterization of p-Coumaric Acid Complexes of CoII, NiII, CuII and ZnII Metal Cations and Biological Applications

T he phenolic compound used in this study is p-coumaric acid, which is the derivative of phenolic acid playing a role in giving color, odor and taste to the plants. The p-coumaric acid is an organic compound derived from cinnamic acid. There are three isomers of this structure as ortho-, meta- and para- depending on the location of the hydroxyl group within the structure. In this study, metal complexes of p-coumaric acid ligand with the transition metal cations CoII, NiII, CuII, ZnII were synthesized. The structure of the synthesized complexes was studied via elemental analysis, infrared and ultraviolet-visible spectroscopy, magnetic measurements, melting point and thermal analysis. Furthermore the biological properties of these new molecules were studie

Covid-19 en Turquía: aburrimiento en el ocio, resiliencia psicológica, actividad física y estado emocional

This research was conducted in the quarantine process implemented in the CoViD-19 outbreak to examine the relationship between the perception of the boredom of individuals in leisure times and psychological resilience levels, and to describe the leisure activities of individuals, participation in physical activity and emotional state. Accordingly, a total of 2214 voluntary individuals living in Turkey participated with 909 men (41.1%) (age=33.83±10.73), and 1305 women (58.9%) (age=32,41±10.02). Within the scope of the study, information about demographic variables, physical activity and emotional state were collected with the form created by the researchers. In the study, "Leisure Boredom Scale" and "Psychological Resilience Scale" were used as the measurement tools. In the study, individuals were asked to write a word expressing their thoughts on the CoViD-19 process for descriptive analyses, and the collected data were visualized with the "MAXQDA" qualitative data analysis program. In addition, the data are presented in charts in the analysis of other variables. In the statistical analysis of the study, descriptive statistics were used, t-test was used to determine the difference between independent groups, Pearson correlation analysis was used to determine the relationships between variables, and simple linear regression analysis was used to determine the strength of the independent variable in predicting the dependent variable. As a result, predominantly negative emotional states were observed in individuals during the quarantine period. However, as the participation in physical activity increases, the level of psychological resilience will increase and the perception of boredom in leisure time will decrease. Besides, it was found that the perception of boredom in leisure time was an important determinant of the level of psychological resilience, and that it explains about 15% of the variance.Esta investigación se realizó en el proceso de cuarentena implementado en el brote de CoViD-19 para examinar la relación entre la percepción del aburrimiento de los individuos en los momentos de ocio y los niveles de resiliencia psicológica, y describir las actividades de ocio de los individuos, la participación en la actividad física y estado emocional. En consecuencia, participaron un total de 2214 personas voluntarias que vivían en Turquía, con 909 hombres (41,1%) (edad=33,83±10,73) y 1305 mujeres (58,9%) (edad=32,41±10,02).En el ámbito del estudio, se recogió información sobre variables demográficas, actividad física y estado emocional con el formulario creado por los investigadores. En el estudio, la "Escala de aburrimiento del ocio" y la "Escala de resiliencia psicológica" se utilizaron como herramientas de medición. En el estudio, se pidió a las personas que escribieran una palabra para expresar sus pensamientos sobre el proceso CoViD-19 para análisis descriptivos, y los datos recopilados se visualizaron con el programa de análisis de datos cualitativos "MAXQDA". Además, los datos se presentan en gráficos en el análisis de otras variables. En el análisis estadístico del estudio se utilizó estadística descriptiva, se utilizó la prueba t para determinar la diferencia entre grupos independientes, se utilizó el análisis de correlación de Pearson para determinar las relaciones entre las variables y se utilizó el análisis de regresión lineal simple para determinar la fuerza de la variable independiente en la predicción de la variable dependiente. Como resultado, se observaron estados emocionales predominantemente negativos en los individuos durante el período de cuarentena. Sin embargo, a medida que aumenta la participación en la actividad física, aumentará el nivel de resiliencia psicológica y disminuirá la percepción de aburrimiento en el tiempo libre. Además, se encontró que la percepción de aburrimiento en el tiempo libre fue un determinante importante del nivel de resiliencia psicológica, y que explica alrededor del 15% de la varianza.Universidad Pablo de Olavid

Antioxidant and antimicrobial activities with GC/MS analysis of the Morus alba L. Leaves

Morus alba L. Moraceae leaves are used effectively to treat fever, protect liver from damage, strengthen the joints, facilitate discharge of urine in Turkey folk medicine. In this study we aimed to determine in vitro antioxidant and antimicrobial activity with GC/MS analysis of the Morus alba L. leaves. Dried plant leaves samples are milled and extracted with distilled water and ethanol in Soxhlet machine. After extraction, extract samples were concentrated in rotary evaporator machine. Total antioxidant status values were determined as mmol Trolox Equivalent/L spectrophotometrically by using Erel’s method. Sterile extracts were used to avoid contamination in antimicrobial activity test. As test microorganisms Escherichia coli ATCC 25922 , Staphylococcus aureus ATCC 25923 , Enterococcus faecalis ATCC 29212 , Pseudomonas aeroginosa ATCC 27853 , Candida albicans ATCC 90028 were used. Antimicrobial activity was determined with disc diffusion method. We used ethanol extracts of samples in GC/MS analysis. Ethanol and distilled water extracts showed antioxidant activity in different rate. Besides, ethanol extracts have an antimicrobial activity but water extracts have not antimicrobial activity on our test microorganisms. We determined four compounds 9,12,15-octadecatrienoic acid, ethyl ester, linolenic acid ethyl ester, gibberellic acid with GC/MS analysis in ethanol extract

May Biochemical Variables and Pleural Fluid Cell Count Be Used in the Benign-Malign Differentiation of Pleural Effusions Associated with Lung Cancer?

Conclusion: In our study, we found that the values of albumin, HCT, RBC and protein in pleural fluid were higher in malignant pleural effusion