First-principles electronic structure and positron state calculations for transition metal carbides and nitrides are performed. Perfect NaC1-structures as well as structures with metal or carbonJnitrogen vacancies are considered. The positron affinities and lifetimes are determined. The trends are discussed and the results are compared with recent positron lifetime measurements for group IV and...

In colonoscopic study, benign colorectal strictures with or without symptomatic pain are not rarely encountered. Benign colorectal stricture can be caused by a number of problems, such as anastomotic stricture after surgery, inflammatory bowel disease, postendoscopic submucosal dissection, diverticular disease, ischemic colitis, and so on. There are various modalities for the management of beni...

This research was conducted for the purpose of studying the effect of CaF2 content in the composition of hot metal pretreatment flux, based on lime. It was followed in regards to the importance of fluorine amount decrease in hot metal pretreatment and steel making processes. For this purpose, lime based fluxes including 40, 30, 20 and 10 percent calcium fluoride were prepared and hot metal pret...

Esophageal variceal bleeding is a serious complication of portal hypertension in cirrhotic patients. Current treatment approach consists of band ligation and sclerotherapy. More than 10% of variceal bleedings are refractory to standard treatments and have a higher mortality rate. In this study, we aimed to share our experiences regarding covered self-expanding metal stent (SEMS) as a bridging t...

Siderophile element distributions within individual metal grains in two CH chondrites, Allan Hills 85085 and Pecora Escarpment 91467, were measured by laser ablation inductively coupled plasma mass spectrometry. Those metal grains that are zoned in Ni were also found to be zoned in other refractory siderophile elements, such as Ru, but not in Pd, which is not refractory but is highly siderophil...