Influence of (0, 1)* Laguerre-Gaussian Field Distribution on Tunneling Ionization Rate

Abstract: In the frame of the ADK theory, the tunneling ionization of an argon atom exposed to the light from Ti:Sapphire laser is investigated. We assume that the laser field is the radially polarized beam with donut. (0, 1)* Laguerre-Gaussian field distribution. Considering that LG (0, 1)* modes can appear with random or uniform polarization (linear, circular or elliptical), we analyzed behavior of transition rate in all three types. We computed transition rate in basic case and in the case when the initial momentum of the ejected electron is included in the equation. Also, we analyzed influence of the modified initial ionization potential of ionized electron on transition rate. In the basic case, we got what we expected but with included effect we find appearance of two transition rate peaks at a certain point of the electron’s exit from the barrier

The influence of heat treatment on the sliding wear behavior of a ZA-27 alloy

The effects of heat treatment, involving solutionizing at temperature of 370 °C for a relatively short period of time (3 or 5 h), followed by quenching in water, on tribological behavior of ZA-27 alloys were examined. Dry sliding wear tests were conducted on as-cast and heat-treated ZA-27 samples using block-on-disk machine over a wide range of applied loads. To determine the wear mechanisms, the worn surfaces of the samples were examined by scanning electron microscopy (SEM). The tribological results were related to the microstructure and mechanical properties. The heat treatment resulted in reduction in the hardness and tensile strength but increase in elongation. The heat-treated alloy samples attained improved tribological behavior over the as-cast ones, both from the aspects of friction and wear. The improved tribological behavior of the heat-treated alloys, in spite of reduced hardness, could be the result of breaking the dendrite structure, when the fraction of interdendrite regions was considerably decreased and a very fine α and η mixture was formed at the same time. The wear response of the samples has been corroborated through characteristics of worn surfaces and dominant wear mechanisms.Publishe

: The effects of shot peening on the fatigue life of machine elements

For increasing the resistance to fatigue and wear, different methods for improvement of contact layers properties are used. First of all, the improvement of properties is realized by heat treatment (induction and flame hardening), chemical-heat treatment (carburizing and nitriding) and plastic surface forming (surface forming by rolls, disks and balls, as well as shot-peening). The paper gives detailed explanation of the shot peening procedure, which involves the ejection of shots at high speed onto the forming object. The intensity of impact is the function of the kinetic energy and angle at which the shot hits the forming object. Thereat, smaller or larger increase of hardness occurs on surface layers, remaining stresses are made, surface topography is changed, and, in some cases, the structural changes are possible (disintegration of remaining austenite). This all leads to increase of fatigue life of elements subjected to shot-peening. The influence of specified effects on the increase of fatigue life depends on strength of material subjected to shot-peening but also on conditions at which the shot-peening process is performed. This paper will present the influence of shot peening on the increase of fatigue life of different parts.Publishe

Overall Survival Time Prediction for High-grade Glioma Patients based on Large-scale Brain Functional Networks

High-grade glioma (HGG) is a lethal cancer with poor outcome. Accurate preoperative overall survival (OS) time prediction for HGG patients is crucial for treatment planning. Traditional presurgical and noninvasive OS prediction studies have used radiomics features at the local lesion area based on the magnetic resonance images (MRI). However, the highly complex lesion MRI appearance may have large individual variability, which could impede accurate individualized OS prediction. In this paper, we propose a novel concept, namely brain connectomics-based OS prediction. It is based on presurgical resting-state functional MRI (rs-fMRI) and the non-local, large-scale brain functional networks where the global and systemic prognostic features rather than the local lesion appearance are used to predict OS. We propose that the connectomics features could capture tumor-induced network-level alterations that are associated with prognosis. We construct both low-order (by means of sparse representation with regional rs-fMRI signals) and high-order functional connectivity (FC) networks (characterizing more complex multi-regional relationship by synchronized dynamics FC time courses). Then, we conduct a graph-theoretic analysis on both networks for a jointly, machine-learning-based individualized OS prediction. Based on a preliminary dataset (N = 34 with bad OS, mean OS, ~400 days; N = 34 with good OS, mean OS, ~1030 days), we achieve a promising OS prediction accuracy (86.8%) on separating the individuals with bad OS from those with good OS. However, if using only conventionally derived descriptive features (e.g., age and tumor characteristics), the accuracy is low (63.2%). Our study highlights the importance of the rs-fMRI and brain functional connectomics for treatment planning

Tribological effects of shot peening surface treatment

Results of laboratory investigations that are presented and analyzed in this paper are directly related to the tribological effects of application of the shot peening process, as the finishing machining operation. Considering the total tribological effects, one can conclude that the final machining of the contact surface by shot peening, can contribute to improvement tribological level of the tribomechanical systems elements.Publishe

SCLC extensive disease – treatment guidance by extent or/and biology of response?

In extensive disease of small cell lung cancer a doubling of the one-year-survival rate was reported in August 2007 by prophylactic cranial irradiation applied to patients who experienced any response to initial chemotherapy. We discuss the treatment concept of extensive disease in the face of the latest results and older studies with additional thoracic irradiation in this subgroup. A randomized trial with prophylactic cranial irradiation published in 1999 demonstrated an improvement of 5-year-overall-survival for complete responders (at least at distant levels) receiving additional thoracic radiochemotherapy compared to chemotherapy alone (9.1% vs. 3.7%). But, these results were almost neglected and thoracic radiotherapy was not further investigated for good responders of extensive disease. However, in the light of current advances by prophylactic cranial irradiation these findings are noteworthy on all accounts. Considering both, a possible interpretation of these data could be a survival benefit of local control by simultaneous thoracic radiochemotherapy in the case of improved distant control due to chemotherapy and prophylactic cranial irradiation. Furthermore the question arises whether the tumor biology indicated by the response to chemotherapy should be integrated in the present classification