CFRP ile güçlendirilmiş betonarme kolonların moment-eğrilik ilişkilerinin incelenmesi

06.03.2018 tarihli ve 30352 sayılı Resmi Gazetede yayımlanan “Yükseköğretim Kanunu İle Bazı Kanun Ve Kanun Hükmünde Kararnamelerde Değişiklik Yapılması Hakkında Kanun” ile 18.06.2018 tarihli “Lisansüstü Tezlerin Elektronik Ortamda Toplanması, Düzenlenmesi ve Erişime Açılmasına İlişkin Yönerge” gereğince tam metin erişime açılmıştır.Ülkemizde ve dünyada son yıllarda yaşananılan depremler sonucu ortaya çıkan can kayıpları ve hasarlar, mevcut yapıların depremlere karşı yetersizliğini gözler önüne sermiş ve güçlendirme ihtiyaçlarını ortaya çıkarmıştır. Bu çalışmada MATLAB tabanlı bilgisayar programında geliştirilmiş olan kod yardımıyla betonarme kolonların eksenel yük düzeyi yüksek ve düşük olmak üzere iki farklı değer için kesit boyutu, CFRP kalınlığı ve beton dayanımı gibi parametrelerinin moment eğrilik ilişkisi üzerindeki etkileri incelenmiştir. Sonuçlar karşılaştırmalı olarak irdelenmiş ve yorumlanmıştır. Çalışmadan elde edilen sonuçlarda, beton dayanımı arttıkça her iki eksenel yük düzeyi için güçlendirilmiş betonarme kolonun sünekliği, dayanımı ve rijitliğinin arttığı söylenebilir. Kullanılan CFRP kalınlığının artışı sonucunca ise eksenel yük düzeyi yüksek olan değerde güçlendirilmiş betonarme kolonun sünekliği ve dayanımı artarken, rijitliğin başlangıç değerinde sabit kaldığı gözlemlenmiştir. Öte yandan CFRP kalınlığının artışı eksenel yük düzeyi düşük olan değerde ise güçlendirilmiş betonarme kolonun sünekliği, dayanımı ve rijitliği arttırdığı gözlemlenmiştir. Anahtar Kelimeler: CFRP, fiber takviyeli polimerler, güçlendirilmiş betonarme kolon, MATLAB.Since earthquakes have great influence, in our country and the world, on the lose of lives and damage generation in buildings, the need for strengthening exciting structures and structural elements is required. In this study and by using a computer code developed and based on MATLAB computer program, and by changing different parameters, like concrete strength, section dimensions, FRP thickness, and different axial loads, the effect of strengthening concrete columns using FRP materials is analyzed, and the results are examined and commented on. Under the two different axial loads, ductility, strength and rigidity of the strengthened concrete using FRP is affected by increasing the concrete compressive strength. Moreover, the thickness of FRP sheets used for strengthening have a considerable affect on strength and ductility of the column when applying the bigger axial load, but the rigidity is unchanged. On the other hand, under the smaller axial load and by increasing FRP thickness all of concrete column characteristics, ductility, Strength and rigidity, are increased. Keywords: CFRP, polymer fiber, concrete column strengthening, MATLA

Importance of Grass Carp (Ctenopharyngodon idella) for Controlling of Aquatic Vegetation

Aquatic plants are beneficial and a necessary part of lakes and reservoirs. Also, some kind of plants are the main food source for aquatic animals. Plants are able to stabilize sediments, improve water clarity and add diversity to the shallow areas of lakes. On the other hand, overgrown plants can become a nuisance by hindering human uses of water and threaten the structure and function of diverse native aquatic ecosystems. This chapter aims to make analysis of using of grass carp to control aquatic vegetation. In this concept, origin and distribution, biological features, reproduction, feeding behaviour and effects of grass carp on aquatic plants, water body and sediments are also discussed

COVID-19 in pediatric patients undergoing chronic dialysis and kidney transplantation

The study aims to present the incidence of COVID-19 in pediatric patients undergoing renal replacement therapy (RRT) and to compare the severity and outcomes of the disease between the dialysis and kidney transplant (KTx) groups. This multicenter observational study was conducted between 1 April and 31 December 2020 in Istanbul. Members of the Istanbul branch of the Turkish Pediatric Nephrology Association were asked to report all confirmed cases of COVID-19 who were on RRT, as well as the number of prevalent RRT patients under the age of 20. A total of 46 confirmed cases of COVID-19 were reported from 12 centers, of which 17 were dialysis patients, and 29 were KTx recipients. Thus, the incidence rate of COVID-19 was 9.3% among dialysis patients and 9.2% among KTx recipients over a 9-month period in Istanbul. Twelve KTx recipients and three dialysis patients were asymptomatic (p = 0.12). Most of the symptomatic patients in both the dialysis and KTx groups had a mild respiratory illness. Only two patients, one in each group, experienced a severe disease course, and only one hemodialysis patient had a critical illness that required mechanical ventilation. In the entire cohort, one hemodialysis patient with multiple comorbidities died. Conclusion: While most cases are asymptomatic or have a mild disease course, pediatric patients undergoing dialysis and a kidney transplant are at increased risk for COVID-19. What is Known: In adult population, both dialysis patients and kidney transplant recipients are at increased risk for severe illness of COVID-19 and have higher mortality rate. Children with kidney transplantation are not at increased risk for COVID-19 and most have mild disease course. Data on children on dialysis are scarce. What is New: Pediatric patients undergoing dialysis and kidney transplantation have an increased risk for COVID-19. Most patients undergoing renal replacement therapy either on dialysis or transplanted develop asymptomatic or mild COVID-19 disease with a favorable outcome

COVID-19 in pediatric nephrology centers in Turkey

Background/aim: There is limited data on COVID-19 disease in children with kidney disease. We aimed to investigate the characteristics and prognosis of COVID-19 in pediatric nephrology patients in Turkey. Materials and methods: This was a national, multicenter, retrospective cohort study based on an online survey evaluating the data between 11th March 2020 and 11th March 2021 as an initial step of a detailed pediatric nephrology COVID-19 registry. Results: Two hundred and three patients (89 girls and 114 boys) were diagnosed with COVID-19. One-third of these patients (36.9%) were between 10–15 years old. Half of the patients were on kidney replacement therapy: kidney transplant (KTx) recipients (n = 56, 27.5%), patients receiving chronic hemodialysis (n = 33, 16.3%) and those on peritoneal dialysis (PD) (n = 18, 8.9%). Fifty-four (26.6%) children were asymptomatic. Eighty-two (40.3%) patients were hospitalized and 23 (28%) needed intensive care unit admission. Fifty-five percent of the patients were not treated, while the remaining was given favipiravir (20.7%), steroid (16.3%), and hydroxychloroquine (11.3%). Acute kidney injury developed in 19.5% of hospitalized patients. Five (2.4%) had MIS-C. Eighty-three percent of the patients were discharged without any apparent sequelae, while 7 (3.4%) died. One hundred and eight health care staff were infected during the study period. Conclusion: COVID-19 was most commonly seen in patients who underwent KTx and received HD. The combined immunosuppressive therapy and frequent exposure to the hospital setting may increase these patients’ susceptibility. Staff infections before vaccination era were alarming, various precautions should be taken for infection control, particularly optimal vaccination coverage

Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study

Funder: European Society of Intensive Care Medicine; doi: http://dx.doi.org/10.13039/501100013347Funder: Flemish Society for Critical Care NursesAbstract: Purpose: Intensive care unit (ICU) patients are particularly susceptible to developing pressure injuries. Epidemiologic data is however unavailable. We aimed to provide an international picture of the extent of pressure injuries and factors associated with ICU-acquired pressure injuries in adult ICU patients. Methods: International 1-day point-prevalence study; follow-up for outcome assessment until hospital discharge (maximum 12 weeks). Factors associated with ICU-acquired pressure injury and hospital mortality were assessed by generalised linear mixed-effects regression analysis. Results: Data from 13,254 patients in 1117 ICUs (90 countries) revealed 6747 pressure injuries; 3997 (59.2%) were ICU-acquired. Overall prevalence was 26.6% (95% confidence interval [CI] 25.9–27.3). ICU-acquired prevalence was 16.2% (95% CI 15.6–16.8). Sacrum (37%) and heels (19.5%) were most affected. Factors independently associated with ICU-acquired pressure injuries were older age, male sex, being underweight, emergency surgery, higher Simplified Acute Physiology Score II, Braden score 3 days, comorbidities (chronic obstructive pulmonary disease, immunodeficiency), organ support (renal replacement, mechanical ventilation on ICU admission), and being in a low or lower-middle income-economy. Gradually increasing associations with mortality were identified for increasing severity of pressure injury: stage I (odds ratio [OR] 1.5; 95% CI 1.2–1.8), stage II (OR 1.6; 95% CI 1.4–1.9), and stage III or worse (OR 2.8; 95% CI 2.3–3.3). Conclusion: Pressure injuries are common in adult ICU patients. ICU-acquired pressure injuries are associated with mainly intrinsic factors and mortality. Optimal care standards, increased awareness, appropriate resource allocation, and further research into optimal prevention are pivotal to tackle this important patient safety threat

Correction to: Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study

The original version of this article unfortunately contained a mistake

Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study

Funder: European Society of Intensive Care Medicine; doi: http://dx.doi.org/10.13039/501100013347Funder: Flemish Society for Critical Care NursesAbstract: Purpose: Intensive care unit (ICU) patients are particularly susceptible to developing pressure injuries. Epidemiologic data is however unavailable. We aimed to provide an international picture of the extent of pressure injuries and factors associated with ICU-acquired pressure injuries in adult ICU patients. Methods: International 1-day point-prevalence study; follow-up for outcome assessment until hospital discharge (maximum 12 weeks). Factors associated with ICU-acquired pressure injury and hospital mortality were assessed by generalised linear mixed-effects regression analysis. Results: Data from 13,254 patients in 1117 ICUs (90 countries) revealed 6747 pressure injuries; 3997 (59.2%) were ICU-acquired. Overall prevalence was 26.6% (95% confidence interval [CI] 25.9–27.3). ICU-acquired prevalence was 16.2% (95% CI 15.6–16.8). Sacrum (37%) and heels (19.5%) were most affected. Factors independently associated with ICU-acquired pressure injuries were older age, male sex, being underweight, emergency surgery, higher Simplified Acute Physiology Score II, Braden score 3 days, comorbidities (chronic obstructive pulmonary disease, immunodeficiency), organ support (renal replacement, mechanical ventilation on ICU admission), and being in a low or lower-middle income-economy. Gradually increasing associations with mortality were identified for increasing severity of pressure injury: stage I (odds ratio [OR] 1.5; 95% CI 1.2–1.8), stage II (OR 1.6; 95% CI 1.4–1.9), and stage III or worse (OR 2.8; 95% CI 2.3–3.3). Conclusion: Pressure injuries are common in adult ICU patients. ICU-acquired pressure injuries are associated with mainly intrinsic factors and mortality. Optimal care standards, increased awareness, appropriate resource allocation, and further research into optimal prevention are pivotal to tackle this important patient safety threat