A robust nanoscale experimental quantification of fracture energy in a bilayer material system

Accurate measurement of interfacial properties is critical any time two materials are bonded—in composites, tooth crowns, or when biomaterials are attached to the human body. Yet, in spite of this importance, reliable methods to measure interfacial properties between dissimilar materials remain elusive. Here we present an experimental approach to quantify the interfacial fracture energy Γ[subscript i] that also provides unique mechanistic insight into the interfacial debonding mechanism at the nanoscale. This approach involves deposition of an additional chromium layer (superlayer) onto a bonded system, where interface debonding is initiated by the residual tensile stress in the superlayer, and where the interface can be separated in a controlled manner and captured in situ. Contrary to earlier methods, our approach allows the entire bonded system to remain in an elastic range during the debonding process, such that Γ[subscript i] can be measured accurately. We validate the method by showing that moisture has a degrading effect on the bonding between epoxy and silica, a technologically important interface. Combining in situ through scanning electron microscope images with molecular simulation, we find that the interfacial debonding mechanism is hierarchical in nature, which is initiated by the detachment of polymer chains, and that the three-dimensional covalent network of the epoxy-based polymer may directly influence water accumulation, leading to the reduction of Γ[subscript i] under presence of moisture. The results may enable us to design more durable concrete composites that could be used to innovate transportation systems, create more durable buildings and bridges, and build resilient infrastructure.National Science Foundation (U.S.) (Grant CMS-0856325

The feasibility of using electromagnetic waves in determining membrane failure through concrete

Concrete flat roof defects such as water leakage present a significant and common problem in large buildings, particularly in tropical countries, where rainfall is high. To monitor this condition, effective non-destructive test methods are required to detect problems at an early stage, especially hidden defects within the concrete roof, which are critical. This paper presents the potential use of electromagnetic (EM) waves for determining possible leakage of the concrete flat roof as a result of failure of the waterproof membrane layer. This study was assessed, experimentally by investigation of the propagation of EM waves through the roof and their interaction with water. Novel Microwave sensors described in the paper operate in the 6 GHz to 12 GHz frequency range using a Marconi 6200A microwave test set. A range of existing methods was reviewed and analysed. Results of experimental tests confirmed that microwaves could be used as an alternative non-destructive method for identifying water ingress caused by membrane failure into the concrete roof surface

Negative emotions set in motion : the continued relevance of #GamerGate

This chapter aims at making sense of the #GamerGate (#GG) online harassment campaign that was particularly active in 2014–2015 but to this day continues to produce hateful speech against certain ideologies and minorities in gaming culture. The campaign was especially successful at building online visibility through harassment, and the affective resonances of the issues it raised have since translated into general online campaigning how-to’s, financial earnings, and even political action outside of the gaming sphere. Although the primary breeding ground for this movement was 4chan (and later, 8chan), it only reached public awareness and visibility – hence, effectiveness – through Twitter and, to a lesser extent, through YouTube. In order to understand the emotional charge and political relevance of this campaign, we rely on both quantitative and qualitative activity analyses of the Twitter users that use the hashtag #GamerGate between 2014 and 2019. In addition to analyzing who were the most active tweeters and what kind of resonance their tweets elicited, we looked into the emotional qualities of their communication. The communication strategies of #GG tweeters took advantage of the language and cultural references of the target demographic to drive a set of topics into public discourse and, further, to political activism. This discourse utilized a combination of affective modes, based mainly on resentment and schadenfreude, that we see echoing in many places on the internet. In the end, we argue that while #GG may have been only one instance of a campaign with harassment elements, the sentiments it cultivated and amplified as well as its operational logics have since been successfully employed in many similar online movements, including the current political campaigning associated with the so-called alt-right.fi=vertaisarvioitu|en=peerReviewed

Trandolapril in overweight patients with mild-to-moderate essential hypertension: The Turkish Multicenter Trandolapril Study

We studied the effect of trandolapril 2 mg once-daily on mild-to-moderate essential hypertension in 325 overweight patients in an open-label, prospective, multicenter study. The male patients had a body mass index >25.5 kg/m(2), and the females >24 kg/m(2). Mild-to-moderate hypertension was defined as a baseline diastolic blood pressure (DBP) of 90 to 110 mm Hg. After a washout period of 2 weeks, patients were treated for 4 weeks. Efficacy analysis was performed on 295 patients. Mean systolic blood pressure (SEP) and DBP fell significantly from 155.7 +/- 16.7/95.8 +/- 8.8 mm Hg to 136.8 +/- 15.9/82.9 +/- 8.0 mm Hg at the end of treatment. The mean reductions in SEP and DBP were 20 mm Hg and 13 mm Hg, respectively. The target blood pressure (DBP <90 mm Hg and a reduction of at least 5 mm Hg) was achieved in 254 (86%) of 295 patients. There was a slight, statistically significant reduction in heart rate after drug therapy. Serum total cholesterol concentrations fell significantly from 216.5 +/- 40.5 mg/dL to 213.7 +/- 40.2 mg/dL, and low-density-lipoprotein cholesterol from 141.7 +/- 39.9 mg/dL to 138.3 +/- 39.4 mg/dL at the end of the trial. No other clinically important changes in hematologic or biochemical variables of clinical importance occurred. The overall incidence of adverse events was 9.6% and included headache in 9 patients, cough in 7, and dizziness in 6. Four patients (1.3%) withdrew from the study because of side effects, but the effects were transient and did not require treatment. We conclude that trandolapril is effective and safe for overweight patients with mild-to-moderate essential hypertension

Efficacy and tolerability of fixed, low-dose combination therapy with verapamil sustained-release and trandolapril in patients with mild to severe essential hypertension uncontrolled by monotherapy: An open-label, multicenter trial

Background: Only 40% to 60% of patients with essential hypertension respond adequately to antihypertensive monotherapy. The combination of an angiotensin-converting enzyme inhibitor and a calcium antagonist, both of which have tissue-protective properties but different mechanisms of action, may lead to an additive antihypertensive effect

Comparison of the effects of trimetazidine and diltiazem on exercise performance in patients with coronary heart disease. The Turkish trimetazidine study (TTS)

Objective-A multicentre, double-blind comparative study was performed to compare the effects of trimetazidine with diltiazem on exercise performance in patients with stable angina pectoris

Coexisting dyslipidemia in hypertensive patients

We point out that a peculiar annihilation of a vortex-antovortex pairobserved numerically by Hertel and Schneider [Phys. Rev. Lett. 97, 177202(2006)] represents the formation and subsequent decay of a skyrmion