Optimization of output power in hollow-waveguide lasers

We present an approximate analysis of the nonlinear operation of the hollow-waveguide laser, including gain saturation and longitudinal- as well as transverse-field distribution of the laser mode. The model presented is general and can be applied to the study of an arbitrary configuration of the waveguide laser. The laser characteristics obtained reveal that the optimal position of the output mirror (which provides maximal power efficiency of the laser system with the other parameters constant) depends on the output-power level and the mirror-reflectivity coefficient. Moreover, it has been shown that when an addition device is introduced into the cavity, the power efficiency also depends on which end of the laser the light power is extracted from.     

Psychosocial aspects of children and families treated with hemodialysis

Introduction: The aim of this study was to analyze the selected psychosocial aspects of chronic kidney disease in children treated with hemodialysis (HD). Methods: The study included 25 children treated with HD aged 2 to 18 years and their parents. Data concerning the illness and socio‐demographic parameters was collected. We used the Paediatric Quality of Life Inventory (PedsQL) for patients and for their parents the PedsQL‐proxy version, General Health Questionnaire (GHQ‐12), Berlin Social Support Scales (BSSS), and the Caregivers Burden Scale (CBS) to evaluate health‐related quality of life (QoL) of HD children and their primary caregivers. Findings: In the PedsQL test, the QoL of HD children was lower than in healthy children. Children treated with HD assessed their QoL on the PedsQL questionnaire higher than the primary caregivers, on all subscales as well as an overall health‐related QoL. Scoring below 2 on the GHQ‐12 test was reported in 56% of mothers, which may indicate that psychological symptoms have intensified. There was no correlation between BSSS, CBS, and GHQ‐12. Discussion: The assessment of QoL in pediatric patients would allow for the earliest possible identification of their nonsomatic problems and irregularities. This could, consequently, contribute to improving QoL in both children with chronic kidney disease and their families.     

Biofunctionalized upconverting CaF<Subscript>2</Subscript>:Yb,Tm nanoparticles for <Emphasis Type="Italic">Candida albicans</Emphasis> detection and imaging

Versatile optimization of the synthesis method and composition of Yb3+ and Tm3+ co-doped CaF2 nanoparticles as well as a novel biofunctionalization method were developed and evaluated.Through multistep synthesis,the luminescence intensity of the Tm3+ activator was enhanced by more than 10-fold compared to standard one-step synthesis.The proposed methods were used to homogenously distribute the doping ions within the nanoparticle's volume and thus reduce luminescence quenching.Optimization of dopant ions concentration led to the selection of the most efficient visible and near-infrared up-converting nanoparticles,which were CaF2 doped with 10％ Yb3+ 0.05％ Tm3+ and 20％ Yb3+ 0.5％ Tm3+,respectively.To illustrate the suitability of the synthesized nanoparticles as bio-labels,a dedicated biofunctionalization method was used,and the nanoparticles were applied for labeling and imaging of Candida albicans cells.This method shows great promise because of extremely low background and high specificity because of the presence of the attached molecules.     

Measurement and analysis of the water hammer in ram pump

Sādhanā - This paper presents the results of experimental research of the phenomena occurring in water ram during a single cycle of its operation. Apart from a brief introduction and...     

Application of a material fatigue damage model in 4PB tests

The fatigue property of an asphalt mix is an important issue in pavement design. This property is often determined with the aid of a four-point bending (4PB) test in controlled deflection mode. The fatigue property is related to the decrease in the calculated complex stiffness modulus, however, due to the non- homogenous stress and strain field in the beam, the measured response does not represent the stiffness modulus of the material but a weighted stiffness value. For a correct interpretation, a fatigue damage material model like the Asphalt Concrete Pavement-Fatigue model is needed. After integration, the calculated and measured responses are compared. By varying the model parameters, an excellent comparison between the two responses is obtained up to a certain number of cycles. This number of cycles is denoted as the fatigue life N _PH . The accumulated dissipated energy at the surface of the beam in the midsection can be expressed as a constant times the fatigue life N _PH to the power z and also as a constant times the product of the fatigue life N _PH and the initial dissipated energy in the first cycle. Using these two findings, a Wöhler curve was established similar to the one directly based on the strain amplitudes and fatigue life data.     

Recommendation of RILEM Technical Committee 250-CSM: Test method for Textile Reinforced Mortar to substrate bond characterization

Textile Reinforced Mortar (TRM), also known as Fabric Reinforced Mortar or Fabric Reinforced Cementitious Matrix, composites are an emerging technology for the external repair and strengthening of existing structures. For most applications, the effectiveness of the TRM reinforcement relies on its bond performance. This recommendation identifies the best practice to characterize the bond behaviour of TRM. A shear bond test method is proposed to determine the peak axial stress (associated with the maximum load that can be transferred from the structural member to the externally bonded TRM reinforcement), the stress–slip relationship and the failure mode that controls the TRM-to-substrate load transfer capacity. Guidelines on specimen manufacturing, experimental setup, test execution, and determination of test results are provided.     

Insulin-like growth factor I-dependent regulation of prolidase activity in cultured human skin fibroblasts

In metastatic breast cancer the goal to reach must be the best possible palliation with minimum discomfort for the patient. We reviewed our experience with radiotherapy (20 or 30 Gy), systemic therapy and brace. Among 2200 breast cancer patients, we extracted 28 potential candidates for resection. All of them developed new metastases outside the treated field within one year. Local control was achieved in 68%, and 80% of them had stable or better performance status at 3 months. From our analysis, even patients with a so called "solitary lesion" do not seem to have a better prognosis than others. We conclude that radiotherapy (with systemic therapy and a brace) is still first-choice treatment for vertebral metastases; CT-guided percutaneous biopsy can avoid worthless major operations. The role of surgery should be limited to neurological compression, severe mechanical instability and to salvage the failures of conservative treatment.