Wear Mechanisms of Hydrogenated DLC in Oils Containing MoDTC

Diamond-Like Carbon (DLC) coatings are well known for offering excellent tribological properties. They have been shown to offer low friction and outstanding wear performance in both dry and lubricated conditions. Application of these coatings for automotive components is considered as a promising strategy to cope with the emerging requirements regarding fuel economy and durability. Commercially available oils are generally optimised to work on conventional ferrous surfaces and are not necessarily effective in lubricating non-ferrous surfaces. Recently, the adverse effect of the Molybdenum DialkyldithioCarbamate (MoDTC) friction modifier additive on the wear performance of the hydrogenated DLC has been reported. However, the mechanisms by which MoDTC imposes this high wear to DLC are not yet well understood. A better understanding of DLC wear may potentially lead to better compatibility between DLC surfaces and current additive technology being achieved. In this work, the wear properties of DLC coatings in the DLC/cast iron (CI) system under boundary lubrication conditions have been investigated to try to understand what appears to be a tribocorrosion-type process. A pin-on-plate tribotester was used to run the experiments using High Speed Steel (HSS) plates coated with 15 at.% hydrogenated DLC (a-C:15H) sliding against CI pins or ceramic balls. The lubricants used in this study are typical examples of the same fully formulated oil with and without ZDDP. The friction and wear responses of the fully formulated oils are discussed in detail. Furthermore, Optical Microscopy (OM) and Scanning Electron Microscopy (SEM), Energy-Dispersive X-ray spectroscopy (EDX), Focused Ion Beam (FIB) and Transmission Electron Microscopy (TEM) were used to observe the wear scar and propose wear mechanisms. The X-ray Photoelectron Spectroscopy (XPS) analysis was performed on the tribofilms to understand the tribochemical interactions between oil additives and the DLC coating. Nano-indentation analysis was conducted to assess potential structural modifications of the DLC coating. Coating hardness data could provide a better insight into the wear mode and failure mechanism of such hard coatings. Given the obtained results, the wear behaviour of the hydrogenated DLC coating was found to depend not only on the presence of ZDDP in the oil formulation but also on the counterpart type. This study revealed that the steel counterpart is a critical component of the tribocouple leading to MoDTC-induced wear of the hydrogenated DLC

Histopathology of Mystus Nemurus Liver That Were Fed with Feed Added with Psidium Guajava and Andrographis Paniculata Ness

This research was conducted on June to August 2014 in the Laboratory of Parasitesand Diseases of Fisheris and Marine Science of Faculty Riau University Pekanbaru. Thepurpose of this research was to determine the structure of (Mystus nemurus) liver that werefed with feed added with Psidium guajava and Andrographis paniculata Ness. The methodused is an experimental using 3 treatments with 3 replicated. The treatment used in thisresearch was Kn (Fishes were not receive any treantent), Kp (Fishes were not receive anytreatment but were infected with A. hydrophila), P1 ( Fishes were fed with feed added with10 g of Psidium guajava and 10 g of Andrographis paniculata Ness and were infected withA. hydrophila (0.1 ml of 108 of A. hydrophila culture), P2 (Fishes were fed with feed addedwith 20 g of Psidium guajava and 20 g of Andrographis paniculata Ness and were infectedwith A. hydrophila (0.1 ml of 108 of A. hydrophila culture), P3 (Fishes were fed with feedadded with 30 g of Psidium guajava and 30 g of Andrographis paniculata Ness and wereinfected with A. hydrophila (0.1 ml of 108 of A. hydrophila culture). Fish organ (liver) wereprocessed for histological studied (formalin fixed, alcohol series, 6 sliced and HE Stained).Result indicate that the structure of liver of the treated fish showing abnormality symptoms,such as necrosis, fatted degeneration and hemorrhage. It can be concluded that feeding offish with 30 g of Psidium guajava and 30 g of Andrographis paniculata Ness is able to treatA. hydrophila infection on Mystus nemurus

Efficacy of imagery rescripting and imaginal exposure for nightmares:A randomized wait-list controlled trial

Nightmares can be effectively treated with cognitive-behavioral therapies. Though it remains elusive which therapeutic elements are responsible for the beneficial effects on nightmare symptoms, imagery rescripting (IR) and imaginal exposure (IE) are commonly identified as active treatment components of nightmare therapies. With this randomized controlled trial, we compared IR and IE as individual treatments to a wait-list (WL) condition to determine whether these particular therapeutic elements ameliorate nightmare symptoms. For this purpose, 104 patients with a primary DSM-5 diagnosis of nightmare disorder were randomly assigned to three weekly individual sessions of either IR or IE, or WL. Results showed that compared to WL, both interventions effectively reduced nightmare frequency (ΔdIR-WL = 0.74; ΔdIE-WL = 0.70) and distress (ΔdIR-WL = 0.98; ΔdIE-WL = 1.35) in a sample that predominantly consisted of idiopathic nightmare sufferers. The effects of IR and IE were comparable to those observed for other psychological nightmare treatments. Initial effects at post-treatment were sustained at 3- and 6-months follow-up, indicating that IR and IE both seem to be efficacious treatment components of nightmare therapies. Additional research is needed to directly compare IR and IE among both idiographic and posttraumatic nightmare sufferers with respect to treatment expectancy, acceptability, and effectiveness

Diagnostic Utility of the Impact of Event Scale-Revised in Two Samples of Survivors of War

The study aimed at examining the diagnostic utility of the Impact of Event Scale-Revised (IES-R) as a screening tool for post-traumatic stress disorder (PTSD) in survivors of war. The IES-R was completed by two independent samples that had survived the war in the Balkans: a sample of randomly selected people who had stayed in the area of former conflict (n = 3,313) and a sample of refugees to Western European countries (n = 854). PTSD was diagnosed using the MINI International Neuropsychiatric Interview. Prevalence of PTSD was 20.1% in the Balkan sample and 33.1% in the refugee sample. Results revealed that when considering a minimum value of specificity of 0.80, the optimally sensitive cut-off score for screening for PTSD in the Balkan sample was 34. In both the Balkan sample and the refugee sample, this cut-off score provided good values on sensitivity (0.86 and 0.89, respectively) and overall efficiency (0.81 and 0.79, respectively). Further, the kappa coefficients for sensitivity for the cut-off of 34 were 0.80 in both samples. Findings of this study support the clinical utility of the IES-R as a screening tool for PTSD in large-scale research studies and intervention studies if structured diagnostic interviews are regarded as too labor-intensive and too costly