227 research outputs found

    Experimental investigation of an Al2O3/distilled water nanofluid used in the heat pipes of heat exchangers

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    This study investigates the thermal performance of a heat pipe heat recovery system in air-to-air heat recovery systems using a nanofluid of Al2O3 (aluminum oxide) particles and distilled water. The experimental setup used 15 wickless vacuumed copper pipes with a length of 1000 mm, a 10.5 mm inner diameter and a 12 mm outer diameter. The evaporator section consists of 450 mm of heat pipes, the condenser section is 400 mm, and the adiabatic section is 150 mm. In experimental studies, 33% of the evaporator volume of the heat pipes was filled with working fluids. Experiments were carried out at temperatures between 25 degrees C and 90 degrees C by using five different cooling air flows (40 g/s, 42 g/s, 45 g/s, 61 g/s and 84 g/s), and two different heating powers (3 kW and 6 kW) for the evaporation section, to determine the heat removed from the condensation section. Experiments were performed for distilled water and Al2O3 nanofluid, respectively, and the results were compared with each other. As a result of the experiments, it was observed that using a nanofluid as the working fluid increased the efficiency of the heat pipe. The highest efficiency (eta = 59%) was obtained in the experiments carried out using an Al2O3 nanofluid at a heating power of 3 kW and an air flow of 112 g/s.This work was supported by Scientific Research Projects Coordination Unit of Karabuk University. Project Number: "KBU-BAP-14/2-DR-018"

    Influences of alumina and fly ash nanofluid usage on the performance of recuperator including heat pipe bundle

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    4th International Conference on Computational and Experimental Science and Engineering (ICCESEN)Energy efficiency becomes one of the most attracting study areas in the world because of the rising environmental issues. It is widely known that a plenty of energy efficiency applications are performed in heat transfer devices. In this regard, it is aimed to improve the thermal performance of recuperator, an air–air heat exchanger, including heat pipe bundle by utilizing a nanofluid, which is the mixture of nanoparticles of a metal oxide and deionized water, by this experimental study. The tests were conducted by filling the heat pipe at the rate of 1/3 of heat pipe volume both deionized water and alumina nanofluid, respectively. Coolant air was used to determine how much heat could be extracted from the condenser section. The findings obtained from the tests show that thermal performance of a heat pipe bundle-including recuperator was remarkably enhanced when nanoparticles containing working fluid was used as the working fluid in place of deionized water. The maximum improvement was achieved as 37.04% during the tests conducted at 6 kW heater power.Scientific Research Projects Coordination Unit of Karabuk University Project Number is "KBu-BAP-14/2-DR-018

    The importance of immature granulocyte and immature reticulocyte fraction for the severity of acute bronchiolitis

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    The immature granulocyte (IG) and immature reticulocyte fraction (IRF) are new analytical parameters of the complete blood count, that have been studied as biomarkers of several inflammatory conditions. Here, our aim is to determine the effectiveness of IG and IRF percentages for the severity of acute bronchiolitis (AB). A single-center, prospective study was performed in patients who were hospitalized for acute bronchiolitis and healthy children were included as a control group. The demographic characteristics, white blood cell (WBC) count, platelet (PLT) count, eosinophil%, IG%, and IRF% values were analysed. Receiver operating characteristics (ROC) analysis was used to compare the diagnostic accuracies and predictive performances. We enrolled 168 infants in the acute bronchiolitis group and 80 in the control group. The Clinical Severity Score (CSS) showed that 48, 93, and 27 patients had mild, moderate, and severe bronchiolitis, respectively. The WBC, PLT, and IRF value were significantly higher in patients (p 12.4, with a sensitivity of 53% and specificity of 88% (Areas under the curves (AUC):0.701,p<0.001). The WBC count, PLT count, and IRF value increased in the AB group. The IRF percentage can be used to predict the clinical severity of AB in children

    Factors that Affect Prognosis and Morbidity in Pediatric Patients with Carbon Monoxide Poisoning

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    Introduction:Carbonmonoxide poisoning continues to be a major health problem worldwide, especially in developing countries, and constitutes an important part of the patients admitted to the pediatric emergency clinics due to poisoning. The aim of this study was to evaluate the correlation between clinical severity, morbidity, hospital stay, intensive care need, and full systemic effects in patients who were followed up and treated for carbon monoxide poisoning in our pediatric emergency clinic.Methods:The study was performed between January 2013 and 2015. We included patients under 18 years of age who were admitted to the pediatric emergency with carbon monoxide poisoning. Assessments were made prospectively. The epidemiological characteristics, complaints, physical examination and vital findings of all patients were recorded. Carboxyhemoglobin (COHb) level, oxygen saturation, electrocardiography, complete blood count, liver and kidney functions, and cardiac enzymes were studied, and Glasgow Coma scale (GCS) was calculated.Results:The mean length of hospital stay for 232 patients was calculated as 7.08±1 hours and the mean duration of exposure to carbon monoxide gas was 3.17±2.5 hours. Higher COHb levels and cardiotoxicity were detected in patients with a longer duration of exposure and a lower GCS and an increased intensive care need (p<0.01). There was no correlation between COHb levels and clinical severity, GCS, or intensive care unit need. However, it was found that high COHb levels (especially above 30%) increased cardiac injury and neurological symptoms but did not cause a permanent sequela (p<0.05). None of the patients had permanent neurological, cardiac, or renal damage.Conclusion:We found that duration of exposure is the most important and accurate parameter for the evaluation of clinical course and morbidity. In patients with high COHb levels, the effects are more prominent, however, we considered that there was no change in sequelae at long-term follow up

    Development and management of ovarian hyperstimulation syndrome in spontaneous singleton pregnancy

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    Ovarian hyperstimulation syndrome (OHSS) is one of the most life-threatening complications of ovulation induction. However, rarely, OHSS can develop spontaneously during pregnancy without induction of ovulation. It has been shown in the literature that some diseases such as polycystic ovary syndrome (PCOS), hypothyroidism, and pituitary adenoma may accompany spontaneous OHSS. Spontaneous OHSS should be included in the differential diagnosis in first-trimester pregnancies with nausea, vomiting, and acute abdomen. The focus should be on preventing possible complications and initiating early treatment immediately after diagnosis

    Mortality from gastrointestinal congenital anomalies at 264 hospitals in 74 low-income, middle-income, and high-income countries: a multicentre, international, prospective cohort study

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    Summary Background Congenital anomalies are the fifth leading cause of mortality in children younger than 5 years globally. Many gastrointestinal congenital anomalies are fatal without timely access to neonatal surgical care, but few studies have been done on these conditions in low-income and middle-income countries (LMICs). We compared outcomes of the seven most common gastrointestinal congenital anomalies in low-income, middle-income, and high-income countries globally, and identified factors associated with mortality. Methods We did a multicentre, international prospective cohort study of patients younger than 16 years, presenting to hospital for the first time with oesophageal atresia, congenital diaphragmatic hernia, intestinal atresia, gastroschisis, exomphalos, anorectal malformation, and Hirschsprung’s disease. Recruitment was of consecutive patients for a minimum of 1 month between October, 2018, and April, 2019. We collected data on patient demographics, clinical status, interventions, and outcomes using the REDCap platform. Patients were followed up for 30 days after primary intervention, or 30 days after admission if they did not receive an intervention. The primary outcome was all-cause, in-hospital mortality for all conditions combined and each condition individually, stratified by country income status. We did a complete case analysis. Findings We included 3849 patients with 3975 study conditions (560 with oesophageal atresia, 448 with congenital diaphragmatic hernia, 681 with intestinal atresia, 453 with gastroschisis, 325 with exomphalos, 991 with anorectal malformation, and 517 with Hirschsprung’s disease) from 264 hospitals (89 in high-income countries, 166 in middleincome countries, and nine in low-income countries) in 74 countries. Of the 3849 patients, 2231 (58·0%) were male. Median gestational age at birth was 38 weeks (IQR 36–39) and median bodyweight at presentation was 2·8 kg (2·3–3·3). Mortality among all patients was 37 (39·8%) of 93 in low-income countries, 583 (20·4%) of 2860 in middle-income countries, and 50 (5·6%) of 896 in high-income countries (p<0·0001 between all country income groups). Gastroschisis had the greatest difference in mortality between country income strata (nine [90·0%] of ten in lowincome countries, 97 [31·9%] of 304 in middle-income countries, and two [1·4%] of 139 in high-income countries; p≤0·0001 between all country income groups). Factors significantly associated with higher mortality for all patients combined included country income status (low-income vs high-income countries, risk ratio 2·78 [95% CI 1·88–4·11], p<0·0001; middle-income vs high-income countries, 2·11 [1·59–2·79], p<0·0001), sepsis at presentation (1·20 [1·04–1·40], p=0·016), higher American Society of Anesthesiologists (ASA) score at primary intervention (ASA 4–5 vs ASA 1–2, 1·82 [1·40–2·35], p<0·0001; ASA 3 vs ASA 1–2, 1·58, [1·30–1·92], p<0·0001]), surgical safety checklist not used (1·39 [1·02–1·90], p=0·035), and ventilation or parenteral nutrition unavailable when needed (ventilation 1·96, [1·41–2·71], p=0·0001; parenteral nutrition 1·35, [1·05–1·74], p=0·018). Administration of parenteral nutrition (0·61, [0·47–0·79], p=0·0002) and use of a peripherally inserted central catheter (0·65 [0·50–0·86], p=0·0024) or percutaneous central line (0·69 [0·48–1·00], p=0·049) were associated with lower mortality. Interpretation Unacceptable differences in mortality exist for gastrointestinal congenital anomalies between lowincome, middle-income, and high-income countries. Improving access to quality neonatal surgical care in LMICs will be vital to achieve Sustainable Development Goal 3.2 of ending preventable deaths in neonates and children younger than 5 years by 2030

    The prevention of non-traumatic home accidents among children aged 0-6 year 0-6 yaş arasındaki çocuklarda travma dışı ev kazalarının önlenmesi

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    © 2021, Galenos. All rights reserved.Introduction:Home accidents are a general problem of societies and most of them are preventable. The aim of this study is to investigate the factors affecting the non-traumatic household and the prevention of accidents in the 0-6 age group. Materials and Methods: We evaluated 335 non-traumatic home accident cases between January 2018-December 2019. The data were collected through a questionnaire developed in the light of the literature. In this form, questions were asked about the characteristics of the children and their families and how the home accident happened. Results: Home accident occurred more frequently in boys. The most common type of home accident was taking medication (45.8%), followed by corrosive substance ingestion (28%), foreign body ingestion and aspiration (26.2%). Most of the cause of home accident was due to family reasons (neglect/inattention). There was a positive correlation between the level of education of parents and home accidents. Neglect/inattention-related home accident increased significantly with the increase in maternal age, the rate of non-working parents and the low level of education of the parents (p<0.001). Conclusions: As a result of our study, we found that the majority of home accidents were not due to the neglect and inattention of the parents. We think that almost all home accidents can be prevented by education. In order to prevent home accidents in children 0-6 years of age, families and child minders should be educated about the developmental characteristics of children, home accidents risk factors, home accidents safety measures and home environments
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