12 research outputs found
Effect of Mill Type on Morphology of AA6013 Aluminium Powder
ABSTRACTIn conventional recycling method, metal chips are cast after pressing and melting in electric arc furnace. Material loss occurs during the recycling from liquid metal due to the several reasons. Direct recycling method which produces the aluminium powder from aluminium chips using mechanical mill can be an alternative to conventional recycling method. Thus material and energy losses, and labour cost will be reduced by direct recycling method without melting.In this study, the particle morphology of powder direct recycled from AA6013 aluminium alloy chips with cryogenic, disc and ball type grinders is investigated. Mechanical milling resulted flaky and irregular shaped AA6013 particles. It was ascertained that the chips did not break sufficiently in despite of the long duration milling mechanisms by ball mill. Cryogenic mill provides the energy required for milling mechanisms to act. Disc mill has the highest impact energy was determined. Consequently, efficiency of ball mill is lower than the efficiency of cryogenic and disc type mills. Shape factors of powders produced with ball and cryogenic mills were found greater than that of the powder produced by disc mill. Disc mill has the most efficient and effective impact energy which produces the smaller particles per minute, was determined.Keywords: Direct recycling method, powder production, scrap chips, aluminium alloy.
Effect of Mill Type on Morphology of AA6013 Aluminium Powder
ABSTRACTIn conventional recycling method, metal chips are cast after pressing and melting in electric arc furnace. Material loss occurs during the recycling from liquid metal due to the several reasons. Direct recycling method which produces the aluminium powder from aluminium chips using mechanical mill can be an alternative to conventional recycling method. Thus material and energy losses, and labour cost will be reduced by direct recycling method without melting.In this study, the particle morphology of powder direct recycled from AA6013 aluminium alloy chips with cryogenic, disc and ball type grinders is investigated. Mechanical milling resulted flaky and irregular shaped AA6013 particles. It was ascertained that the chips did not break sufficiently in despite of the long duration milling mechanisms by ball mill. Cryogenic mill provides the energy required for milling mechanisms to act. Disc mill has the highest impact energy was determined. Consequently, efficiency of ball mill is lower than the efficiency of cryogenic and disc type mills. Shape factors of powders produced with ball and cryogenic mills were found greater than that of the powder produced by disc mill. Disc mill has the most efficient and effective impact energy which produces the smaller particles per minute, was determined.Keywords: Direct recycling method, powder production, scrap chips, aluminium alloy.
Evaluation of patients with fibrotic interstitial lung disease: Preliminary results from the Turk-UIP study
OBJECTIVE: Differential diagnosis of idiopathic pulmonary fibrosis (IPF) is important among fibrotic interstitial lung diseases (ILD). This study aimed to evaluate the rate of IPF in patients with fibrotic ILD and to determine the clinical-laboratory features of patients with and without IPF that would provide the differential diagnosis of IPF.
MATERIAL AND METHODS: The study included the patients with the usual interstitial pneumonia (UIP) pattern or possible UIP pattern on thorax high-resolution computed tomography, and/or UIP pattern, probable UIP or possible UIP pattern at lung biopsy according to the 2011 ATS/ERSARS/ALAT guidelines. Demographics and clinical and radiological data of the patients were recorded. All data recorded by researchers was evaluated by radiology and the clinical decision board.
RESULTS: A total of 336 patients (253 men, 83 women, age 65.8 +/- 9.0 years) were evaluated. Of the patients with sufficient data for diag-nosis (n=300), the diagnosis was IPF in 121 (40.3%), unclassified idiopathic interstitial pneumonia in 50 (16.7%), combined pulmonary fibrosis and emphysema (CPFE) in 40 (13.3%), and lung involvement of connective tissue disease (CTD) in 16 (5.3%). When 29 patients with definite IPF features were added to the patients with CPFE, the total number of IPF patients reached 150 (50%). Rate of male sex (p<0.001), smoking history (p<0.001), and the presence of clubbing (p=0.001) were significantly high in patients with IPE None of the women <50 years and none of the men <50 years of age without a smoking history were diagnosed with IPE Presence of at least 1 of the symptoms suggestive of CTD, erythrocyte sedimentation rate (ESR), and antinuclear antibody (FANA) positivity rates were significantly higher in the non-IPF group (p<0.001, p=0.029, p=0.009, respectively).
CONCLUSION: The rate of IPF among patients with fibrotic ILD was 50%. In the differential diagnosis of IPF, sex, smoking habits, and the presence of clubbing are important. The presence of symptoms related to CTD, ESR elevation, and EANA positivity reduce the likelihood of IPF
LAZERLE KAYNAK İSLEMİNDE KAYNAK PARAMETRELERİNİN KAYNAK KALİTESİ ÜZERİNDEKİ ETKİLERİNİN İNCELENMESİ
Lazer kaynak yöntemi geleneksel kaynak yöntemlerine göre birçok üstün
özelliklere sahiptir. Düsük ısı girdisi, dar bir ITAB olusumu, düsük kalıntı
gerilmeleri ve çarpılmalar, yüksek kaynak hızı, derin nüfuziyet, kusursuz
kaynak profili, yüksek yapısal dayanım, otomasyonla birlestirme lazer
kaynagının saglamıs oldugu öncelikli avantajlardır. Bunun yanı sıra yüksek
verimlilik ve ekonomiklik, düsük hata oranı diger faydalı özelliklerindendir.
Bu çalısmada 50x40 mm ebatlarında 2,0 mm kalınlıgında AISI 304 paslanmaz
çelik malzemeler lazer kaynagıyla alın alına birlestirilmis, bu malzemelerden
elde edilen 20x80 mm ebatlarındaki numunelerde metalografik incelemeler
yapılmıs, kaynak bölgesinin sertligi ölçülmüs, TS 282 EN 910 standartlarında
belirtilen esaslarla üç nokta egme deneyi yapılmıstır. Elde edilen sonuçlara
göre, kaynak bölgelerinde malzeme kalınlıgı (2 mm) boyunca tam nüfuziyet elde
edilmistir ve katılasan kaynak metali anahtar deligi formundadır. Kaynak
hızının artmasıyla kaynak metali genisliginin azaldıgı tespit edilmistir.
Katılasan kaynak metalinde östenit fazı ile tane ve alt tane sınırlarında olusan
ferrit fazı tespit edilmistir. Kaynak hızı arttıkça geçis bölgesi genisliginin
azaldıgı tespit edilmistir. ITAB'ta kaynak metalinden esas metale dogru uzanan
yatay dogrultuda ferrit bantları tespit edilmistir. Kaynak parametreleriyle
(lazer gücü, kaynak hızı) ferrit bantlarının olusumları arasında iliskiler tespit
edilmistir. Sertlik, esas metalden kaynak metaline dogru artıs göstermistir. Isı
arttıkça kaynak metali sertligi ve egme dayanımı genel anlamda arttıgı
görülmektedir
Evaluation of Patients with Fibrotic Interstitial Lung Disease: Preliminary results from the Turk-UIP Study
OBJECTIVE: Differential diagnosis of idiopathic pulmonary fibrosis (IPF) is important among fibrotic interstitial lung diseases (ILD). This study aimed to evaluate the rate of IPF in patients with fibrotic ILD and to determine the clinical-laboratory features of patients with and without IPF that would provide the differential diagnosis of IPF
The prevalence of childhood psychopathology in Turkey: a cross-sectional multicenter nationwide study (EPICPAT-T).
Aim: The aim of this study was to determine the prevalence of childhood psychopathologies in Turkey
The prevalence of childhood psychopathology in Turkey: a cross-sectional multicenter nationwide study (EPICPAT-T)
Conclusion: This is the largest and most comprehensive epidemiological study to determine the prevalence of psychopathologies in children and adolescents in Turkey. Our results partly higher than, and partly comparable to previous national and international studies. It also contributes to the literature by determining the independent predictors of psychopathologies in this age group
Prevalence of Childhood Affective disorders in Turkey: An epidemiological study
Aim: To determine the prevalence of affective disorders in Turkey among a representative sample of Turkish population.
Methods: This study was conducted as a part of the "The Epidemiology of Childhood Psychopathology in Turkey" (EPICPAT-T) Study, which was designed by the Turkish Association of Child and Adolescent Mental Health. The inclusion criterion was being a student between the second and fourth grades in the schools assigned as study centers. The assessment tools used were the K-SADS-PL, and a sociodemographic form that was designed by the authors. Impairment was assessed via a 3 point-Likert type scale independently rated by a parent and a teacher.
Results: A total of 5842 participants were included in the analyses. The prevalence of affective disorders was 2.5 % without considering impairment and 1.6 % when impairment was taken into account. In our sample, the diagnosis of bipolar disorder was lacking, thus depressive disorders constituted all the cases. Among depressive disorders with impairment, major depressive disorder (MDD) (prevalence of 1.06%) was the most common, followed by dysthymia (prevalence of 0.2%), adjustment disorder with depressive features (prevalence of 0.17%), and depressive disorder-NOS (prevalence of 0.14%). There were no statistically significant gender differences for depression. Maternal psychopathology and paternal physical illness were predictors of affective disorders with pervasive impairment.
Conclusion: MDD was the most common depressive disorder among Turkish children in this nationwide epidemiological study. This highlights the severe nature of depression and the importance of early interventions. Populations with maternal psychopathology and paternal physical illness may be the most appropriate targets for interventions to prevent and treat depression in children and adolescents