Comments to On the Accuracy of Lamb Shift Measurements in Hydrogen (Physica Scripta, 55 (1997) 33-40) by V. G. Pal'chikov, Yu. L. Sokolov, and V. P. Yakovlev

The work is a comments on the article of V. G. Pal'chikov, Yu. L. Sokolov, and V. P. Yakovlev, devoted to the measurement of the Lamb shift in the hydrogen atom and published in Physica Scripta, 55 (1997) 33-40.Comment: 4 pages; [email protected]

Features of arc surfacing of intermetallic alloys of the Fe–Al system on the surface of low-carbon steels

The durability of industrial components is largely determined by the materials they are made of. Often, the materials used must be resistant to wear, corrosion, and high temperatures. Advanced materials, such as high-strength alloy steels, are expensive and have limited weldability, which complicates the restoration of worn components. Fe–Al alloys having high corrosion resistance, wear resistance, and heat resistance at a lower cost are considered as an alternative. The objective of this study is to increase the wear resistance and heat resistance of low-carbon steel components by studying the processes of arc surfacing of iron aluminides and their properties. The study methodology included single-arc and double-arc surfacing using aluminium and steel electrode wires, analysis of the chemical composition of the deposited coatings, their hardness, wear resistance, and heat resistance. The results showed that single-arc surfacing forms alloys based on FeAl3 and α-Al phases with Fe2Al5 and FeAl3 inclusions, while double-arc surfacing produces alloys more saturated with iron with an α-Fe matrix phase and a Fe3AlCx carbide phase. The resulting alloys demonstrate a hardness of up to 58 HRC, a relative wear resistance of up to 2.5 units, and a weight loss of no more than 5 % with an aluminium content of up to 20 %, which indicates their potential for use under high loading conditions. The results confirm the feasibility of using iron aluminides as an inexpensive alternative to expensive coatings, which expands the possibilities for increasing the wear resistance and heat resistance of components in industry

Relativistic recoil corrections to the electron-vacuum-polarization contribution in light muonic atoms

The relativistic recoil contributions to the Uehling corrections are revisited. We consider a controversy in recent calculations based on different approaches including Breit-type and Grotch-type calculations. We have found that calculations of those authors were in fact done in different gauges and in some of those gauges contributions the retardation and two-photon-exchange effects were missed. We have evaluated such effects and obtained a consistent result from those approaches. We present a correct expression for the Grotch-type approach which produces a correct gauge-invariant result. We also consider a finite-nuclear-size correction for the Uehling term. The results are presented for muonic hydrogen and deuterium atoms and for muonic helium-3 and helium-4 ions.Comment: Submitted to Phys. Rev. A; in v.2 results for muonic helium are correcte

Clinical, Epidemiologic, Histopathologic and Molecular Features of an Unexplained Dermopathy

BACKGROUND: Morgellons is a poorly characterized constellation of symptoms, with the primary manifestations involving the skin. We conducted an investigation of this unexplained dermopathy to characterize the clinical and epidemiologic features and explore potential etiologies. METHODS: A descriptive study was conducted among persons at least 13 years of age and enrolled in Kaiser Permanente Northern California (KPNC) during 2006-2008. A case was defined as the self-reported emergence of fibers or materials from the skin accompanied by skin lesions and/or disturbing skin sensations. We collected detailed epidemiologic data, performed clinical evaluations and geospatial analyses and analyzed materials collected from participants' skin. RESULTS: We identified 115 case-patients. The prevalence was 3.65 (95% CI = 2.98, 4.40) cases per 100,000 enrollees. There was no clustering of cases within the 13-county KPNC catchment area (p = .113). Case-patients had a median age of 52 years (range: 17-93) and were primarily female (77%) and Caucasian (77%). Multi-system complaints were common; 70% reported chronic fatigue and 54% rated their overall health as fair or poor with mean Physical Component Scores and Mental Component Scores of 36.63 (SD = 12.9) and 35.45 (SD = 12.89), respectively. Cognitive deficits were detected in 59% of case-patients and 63% had evidence of clinically significant somatic complaints; 50% had drugs detected in hair samples and 78% reported exposure to solvents. Solar elastosis was the most common histopathologic abnormality (51% of biopsies); skin lesions were most consistent with arthropod bites or chronic excoriations. No parasites or mycobacteria were detected. Most materials collected from participants' skin were composed of cellulose, likely of cotton origin. CONCLUSIONS: This unexplained dermopathy was rare among this population of Northern California residents, but associated with significantly reduced health-related quality of life. No common underlying medical condition or infectious source was identified, similar to more commonly recognized conditions such as delusional infestation

Real-time laser speckle contrast imaging for intraoperative neurovascular blood flow assessment: animal experimental study

The use of various blood flow control methods in neurovascular interventions is crucial for reducing postoperative complications. Neurosurgeons worldwide use different methods, such as contact Dopplerography, intraoperative indocyanine videoangiography (ICG) video angiography, fluorescein angiography, flowmetry, intraoperative angiography, and direct angiography. However, there is no noninvasive method that can assess the presence of blood flow in the vessels of the brain without the introduction of fluorescent substances throughout the intervention. The real-time laser-speckle contrast imaging (LSCI) method was studied for its effectiveness in controlling blood flow in standard cerebrovascular surgery cases in rat common carotid arteries, such as proximal occlusion, trapping, reperfusion, anastomosis, and intraoperative vessel thrombosis. The real-time LSCI method is a promising method for use in neurosurgical practice. This approach allows timely diagnosis of intraoperative disturbance of blood flow in vessels in cases of clip occlusion or thrombosis. Additionally, LSCI allows us to reliably confirm the functioning of the anastomosis and reperfusion after removal of the clips and thrombolysis in real time. An unresolved limitation of the method is noise from movements, but this does not reduce the value of the method. Additional research is required to improve the quality of the data obtained

Autorinnen und Autoren

This collection brings together the articles dedicated to the 60th birthday of Professor Wolf Schmid, one of the foremost literary scholars of our times who made a crucial contribution to a wide range of scholarly fields: narratology, poetics, history of Russian and Slavic literature, Pushkin and Dostoevsky. The contributors form a distinguished international group of prominent scholars whose essays in this volume further develop Wolf Schmid\u27s narratological theory, shed new light on major works of literature and offer fascinating new insights into various periods of literary history.This collection brings together the articles dedicated to the 60th birthday of Professor Wolf Schmid, one of the foremost literary scholars of our times who made a crucial contribution to a wide range of scholarly fields: narratology, poetics, history of Russian and Slavic literature, Pushkin and Dostoevsky. The contributors form a distinguished international group of prominent scholars whose essays in this volume further develop Wolf Schmid\u27s narratological theory, shed new light on major works of literature and offer fascinating new insights into various periods of literary history

Schriftenverzeichnis von Wolf Schmid

This collection brings together the articles dedicated to the 60th birthday of Professor Wolf Schmid, one of the foremost literary scholars of our times who made a crucial contribution to a wide range of scholarly fields: narratology, poetics, history of Russian and Slavic literature, Pushkin and Dostoevsky. The contributors form a distinguished international group of prominent scholars whose essays in this volume further develop Wolf Schmid\u27s narratological theory, shed new light on major works of literature and offer fascinating new insights into various periods of literary history.This collection brings together the articles dedicated to the 60th birthday of Professor Wolf Schmid, one of the foremost literary scholars of our times who made a crucial contribution to a wide range of scholarly fields: narratology, poetics, history of Russian and Slavic literature, Pushkin and Dostoevsky. The contributors form a distinguished international group of prominent scholars whose essays in this volume further develop Wolf Schmid\u27s narratological theory, shed new light on major works of literature and offer fascinating new insights into various periods of literary history