A New Problem of Adolescents: "Bonsai"

Synthetic cannabinoids have been increasingly used by adolescents in the recent years. In our country, synthetic cannabinoids are known as "bonsai". They may cause neuropsychiatric effects such as psychosis, agitation, ataxia, convulsion, hallucinations, and may also cause cardiovascular symptoms such as tachycardia, systolic hypertension, postural hypotension and chest pain. In this article, three adolescent males are reported, who were admitted to the emergency department with severe chest pain and significantly higher cardiac enzymes, and who claimed to have used "bonsai"

B4C /Al KOMPOZİTLERİN TAKVİYE HACİM ORANINA BAĞLI OLARAK ABRASİF AŞINMA DAVRANIŞLARININ İNCELENMESİ

Bu çalışmada, toz metalurjisi yöntemi ile üretilen Al matrisli B4C parçacık takviyeli kompozitlerin kuru kayma koşullarındaki aşınma davranışları incelenmiştir. Kompozitlerin karekterizasyonu mikroyapı incelemeleri, sertlik ölçümleri ve abrasif aşınma deneyleri ile yapılmıştır. Abrasif aşınma testleri, 180 ve 400 Mesh Al2O3 zımpara kullanılarak 10 N ve 20 N yük altında 0,2 m s-1 kayma hızında gerçekleştirilmiştir. Sertlik B4C parçacık ilavesi ile birlikte artmıştır. % 20 B4C parçacık takviyeli kompozit en yüksek sertlik gösterirken, % 10 B4C parçacık takviyeli kompozit en yüksek aşınma direnci göstermiştir

Sensor based cyber attack detections in critical infrastructures using deep learning algorithms

The technology that has evolved with innovations in the digital world has also caused an increase in many security problems. Day by day, the methods and forms of cyberattacks are becoming more complicated; therefore, their detection has become more difficult. In this work, we have used datasets that have been prepared in collaboration with the Raymond Borges and Oak Ridge National Laboratories. These datasets include measurements of the Industrial Control Systems related to chewing attack behavior. These measurements include synchronized measurements and data records from Snort and relays with a simulated control panel. In this study, we developed two models using these datasets. The first is a model we call the DNN model, which was build using the latest deep learning algorithms. The second model was created by adding the AutoEncoder structure to the DNN model. All of the variables used when developing our models were set parametrically. A number of variables such as the activation method, the number of hidden layers in the model, the number of nodes in the layers, and the number of iterations were analyzed to create the optimum model design. When we run our model with optimum settings, we obtained better results than those found in related studies. The learning speed of the model has a 100% accuracy rate, which is also entirely satisfactory. While the training period of the dataset containing about 4 thousand different operations lasts for about 90 seconds, the developed model completes the learning process at a level of milliseconds to detect new attacks. This increases the applicability of the model in the real-world environment

Detection of attack-targeted scans from the Apache HTTP Server access logs

A web application could be visited for different purposes. It is possible for a web site to be visited by a regular user as a normal (natural) visit, to be viewed by crawlers, bots, spiders, etc. for indexing purposes, lastly to be exploratory scanned by malicious users prior to an attack. An attack targeted web scan can be viewed as a phase of a potential attack and can lead to more attack detection as compared to traditional detection methods. In this work, we propose a method to detect attack-oriented scans and to distinguish them from other types of visits. In this context, we use access log files of Apache (or ISS) web servers and try to determine attack situations through examination of the past data. In addition to web scan detections, we insert a rule set to detect SQL Injection and XSS attacks. Our approach has been applied on sample data sets and results have been analyzed in terms of performance measures to compare our method and other commonly used detection techniques. Furthermore, various tests have been made on log samples from real systems. Lastly, several suggestions about further development have been also discussed

Parental psychological distress associated with COVID-19 outbreak: A large-scale multicenter survey from Turkey

Aims: Pandemics can cause substantial psychological distress; however, we do not know the impact of the COVID-19 related lockdown and mental health burden on the parents of school age children. We aimed to comparatively examine the COVID-19 related the stress and psychological burden of the parents with different occupational, locational, and mental health status related backgrounds. Methods: A large-scale multicenter online survey was completed by the parents (n = 3,278) of children aged 6 to 18 years, parents with different occupational (health care workers—HCW [18.2%] vs. others), geographical (İstanbul [38.2%] vs. others), and psychiatric (child with a mental disorder [37.8%]) backgrounds. Results: Multivariable logistic regression analysis showed that being a HCW parent (odds ratio 1.79, p <.001), a mother (odds ratio 1.67, p <.001), and a younger parent (odds ratio 0.98, p =.012); living with an adult with a chronic physical illness (odds ratio 1.38, p <.001), having an acquaintance diagnosed with COVID-19 (odds ratio 1.22, p =.043), positive psychiatric history (odds ratio 1.29, p <.001), and living with a child with moderate or high emotional distress (odds ratio 1.29, p <.001; vs. odds ratio 2.61, p <.001) were independently associated with significant parental distress. Conclusions: Parents report significant psychological distress associated with COVID-19 pandemic and further research is needed to investigate its wider impact including on the whole family unit. © The Author(s) 2020

AlSi10Mg Döküm Alaşımlarının Bazı Mekanik Özellikleri Üzerine İkincil Yaşlandırma İşleminin Etkisi

In this paper, effect of secondary ageing process on the hardness and the abrasive wear resistance of AlSi10Mg casting alloys was studied. In the T6 temper heat treatment, AlSi10Mg alloy was aged at 170 ˚C for 4 hours. In secondary ageing process, AlSi10Mg alloy aged at 170 ˚C for 10 or 30 minutes was re-aged at 100 ˚C for 135 hours. Abrasive wear tests were performed on pin-on disk abrasive wear tester under 20 N and 30 N loads and 180 Mesh abrasive papers and at the sliding speed of 0.2 ms-1. Abrasive wear test results revealed that specimen aged at 170 ˚C for 30 minutes and then re-aged at 100 ˚C for 135 hours has the highest abrasive wear resistanc

Takviye Parçacık Boyutunun SiO2 Takviyeli Al-Si Kompozitlerin Abrasiv Aşınma Davranışı Üzerinde Etkisi

Bu çalışmada, silika parçacık takviyeli Al matrisli kompozitlerin iki gövdeli abrasif aşınma davranışı incelenmiştir. Metal matris kompozitler vakum infiltrasyon yöntemi ile üretilmiştir. Takviye olarak ortalama 120 and 80 ^m boyutlarına sahip SiO2 parçacıklar kullanılmıştır. Metal matris ile takviye arasındaki ıslatabilirliği teşvik etmek için Al10Si alaşımına % 5 Mg ilave edilmiştir. Aşınma testleri pin on disk aşınma cihazında 10, 20, 30 N yük altında ve 60, 100, 220 ve 400 Mesh abrasif zımpara kağıdında yapılmıştır. Kompozitlerin aşınma dayanımı artan takviye parçacık boyutu ile artmaktadır. Sonuçlar, aynı zamanda artan yük uygulaması ve abrasif parçacık boyutu ile abrasif aşınma dayanımının düştüğünü göstermiştir. Kompozitlerde baskın aşınma parametresi abrasif parçacık boyutu iken, matris malzemede bunun uygulanan yük olduğu bulunmuştur. Anahtar Kelimeler: Abrasif Aşınma, Metal Matris Kompozit, Takviye Parçacık Boyut

Effect of the cooling in the austempering process on the abrasive wear behaviour of austempered ductile iron

Bu çalışmada, geleneksel tek kademeli östemperleme işleminde, küresel grafitli dökme demir (KGDD) numuneler 900oC’de 1 saat östenitlenmiş, müteakiben tuz banyosunda 400oC’de 2 saat östemperlenmiştir. İkikademeli östemperleme prosesinde ise KGDD numuneler 900oC de 1 saat östenitlendikten sonra derhal 400oC’lik tuz banyosuna aktarılmış, 10 dakika bu sıcaklıkta bekletildikten sonra banyonun sıcaklığı 1.88oC/dak hızla 250oC’a soğutulmuştur. Geleneksel tek kademeli östemperleme prosesi ile üretilen üst ösferritik ve ikikademeli prosesle üretilen üst ve alt ösferritik Östemperlenmiş Küresel Grafitli Dökme Demir (ÖKGDD) numunelerin abrasiv aşınma deneyleri, disk üzerinde pim cihazında 10, 20 ve 30 N normal yük altında, 180 mesh (80 µm) boyuta sahip Al2O3 zımpara üzerinde gerçekleştirilmiştir. İki kademeli östemperleme prosesiyle üretilen küresel grafitli dökme demirin sertliği, tek kademeli prosesle üretilen dökme demirinkinden daha yüksek olmasına rağmen, her iki dökme demirin benzer abrasiv aşınma davranışı sergilediği görülmüştür. Ayrıca iki kademeli östemperlenmiş küresel grafitli dökme demirde abrasiv aşınma direnci uygulanan yükün artmasıyla artmıştır.In this study, ductile iron was austenised at 900 oC for 1 h and austempered at 400 0C for 2 h in single step austempering process, whereas it was austenised at 900 oC for 1 h and immediately quenched in a salt bath at 400 oC for 10 minutes and then the temperature of bath was decreased by 1.88 oC per minutes down to 250 oC in two-step austempering process. The upper ausferritic austempered ductile iron (ADI) specimens produced by conventional single step austempering process and the upper and lower ausferritic specimens produced by twostep austempering process were abraded on the pin on disc apparatus under the normal load of 10, 20, 30 N, by rubbing the specimens on abrasive Al2O3 grains with diameters of 180 Mesh (80 &micro;m). Although the ductile iron austempered in two steps had higher hardness than the ductile iron austempered in single step, they showed similar abrasive wear behavior. In addition, the abrasive wear resistance of two step austempered specimen increased with increasing applied load

Effect of the matrix structure on the friction coefficient and pin tempureture of ductile iron under dry sliding conditions

Bu çalışmada, matris yapısının küresel grafitli dökme demirin (KGDD) aşınma davranışına, aşınma sırasında oluşan sürtünme katsayısına ve pim sıcaklığına etkisi araştırılmıştır. Aşınma testleri disk üzerinde pim türü cihazda, 1 m s-1 kayma hızında, 20, 40 ve 60 N yük ve 3,6 km kayma mesafesinde, normal atmosfer şartlarında ve oda sıcaklığında gerçekleştirilmiştir. Aşınma yüzeyleri tarama elektron mikroskobu (SEM) ile incelenmiştir. Uygulanan yükün artmasına bağlı olarak döküm durumu ferritik KGDD’in aşınma hızı artarken, döküm durumu perlitik KGDD numunenin aşınma hızı azalmaktadır. Testler, döküm durumu perlitik KGDD’nin sürtünme katsayısı ve sürtünme sıcaklığının, döküm durumu ferritik KGDD’den daha yüksek olduğunu göstermiştir. Deneysel sonuçlar, döküm durumu perlitik ve ferritik KGDD’lerin sürtünme katsayısının azalmasıyla, sürtünme sıcaklığının arttığını ortaya koymaktadır.In this study, the effect of the matrix structure on the dry sliding wear behaviour, friction coefficient and pin temperature of ductile irons was investigated. Wear tests were carried out at normal atmospheric conditions and room temperature on a pin on disc type tester at constant sliding speed (1ms-1) and sliding distance (3.6 km) under various sliding loads in a range of 20 to 60 N. The worn surfaces were examined by scanning electron microscopy (SEM). Wear rate of as-cast ferritic ductile irons increased with increasing test load, whilst that of as-cast pearlitic irons decreased. Tests revealed that, as-cast pearlitic ductile iron exhibited higher friction coefficient and friction temperature than as-cast ferritic ductile iron. The experimental results showed that the friction temperature increased with decreasing the friction coefficient of as-cast ferritic and pearlitic ductile irons