71 research outputs found
Ordering of [alpha]-FeCo phase in the nanocrystalline Fe83-xCoxNb3B13Cu1 (x = 6, 25 or 41.5) alloys
The microstructure and ordering of α-FeCo phase of the nanocrystalline Fe83−xCoxNb3B13Cu1 (x = 6, 25 or
41.5) alloys were investigated. We have stated that α-FeCo phase is atomically ordered in the Fe83−xCoxNb3B13Cu1 (x = 25 or 41.5) samples crystallized by the heat treatment in a furnace. However, after flash annealing (by current or laser) that phase is disordered. Moreover, we have found that Co concentration in the crystalline α-FeCo phase strongly depends on Co content in the as-quenched ribbons. The annealing conditions influence also the grain diameter of the crystalline phase. In the nanocrystalline alloys obtained by a flash annealing of the amorphous ribbons finer grains are present
Influence of spatial distribution and the type of material on the occurrence of bandgaps in phononic crystals
The study investigated the effect of the fill factor, lattice constant, and the shape and type of meta-atom material on the reduction of mechanical wave transmission in quasi-two-dimensional phononic structures. A finite difference algorithm in the time domain was used for the analysis, and the obtained time series were converted into the frequency domain using the discrete Fourier transform. The use of materials with large differences in acoustic impedance allowed to determine the influence of the meta-atom material on the propagation of the mechanical wave
Transcervical Extended Mediastinal Lymphadenectomy (TEMLA) for staging of non-small-cell lung cancer (NSCLC)
Wstęp: Celem pracy jest przeanalizowanie wyników nowej techniki operacyjnej — rozszerzonej limfadenektomii śródpiersia
z dostępu szyjnego (TEMLA) w diagnostyce przedoperacyjnej niedrobnokomórkowego raka płuca (NDRP).
Materiał i metody: Operacji dokonywano z cięcia szyjnego o długości 5-8 cm, z uniesieniem rękojeści mostka za pomocą
specjalnego retraktora, z obustronnym uwidocznieniem nerwów krtaniowych wstecznych oraz błędnych i wypreparowaniem
wszystkich stacji węzłowych śródpiersia, z wyjątkiem węzłów więzadła płucnego (stacja 9).
Wyniki: W okresie od 1 stycznia 2004 roku do 31 stycznia 2010 roku zoperowano 698 chorych (577 mężczyzn i 121 kobiet)
w średnim wieku 62,8 roku (41-79), w tym 501 raków płaskonabłonkowych, 144 raki gruczołowe, 25 raków wielokomórkowych
i 28 pozostałych. Średni czas operacji wyniósł 128 minut (45-330 minut) w całej grupie, zaś w grupie ostatnich 100
pacjentów średni czas operacji wyniósł 106 minut. Śmiertelność 30-dniowa wyniosła 0,7% (z przyczyn niezwiązanych
bezpośrednio z zabiegiem), zaś powikłania wystąpiły u 6,6% chorych. Średnia liczba usuniętych węzłów chłonnych wyniosła
37,9 (15-85). Przerzutowe węzły N2 i N3 stwierdzono u odpowiednio 21,8% (152/698) i 3,7% (26/698) chorych. Torakotomii
poddano 445/513 (86,7%) chorych po ujemnym wyniku TEMLA. W czasie torakotomii przeoczone przerzutowe węzły chłonne
N2 stwierdzono w 7/445 (1,6%) przypadkach. Czułość diagnostyczna TEMLA w wykrywaniu przerzutowych węzłów
śródpiersia wyniosła 96,2%, swoistość 100%, dokładność 99,0%, negatywna wartość predykcyjna (NPV) 98,7%, a pozytywna
wartość predykcyjna (PPV) 100%.
Wnioski: Technika TEMLA jest nową, minimalnie inwazyjną metodą chirurgiczną, zapewniającą wyjątkową możliwość
wykonania bardzo rozległej, obustronnej limfadenektomii śródpiersia i charakteryzującą się bardzo wysoką wartością diagnostyczną.
Pneumonol. Alergol. Pol. 2011; 79, 3: 196-206Introduction: The aim of the study is to analyze diagnostic yield of the new surgical technique - the Transcervical
Extended Mediastinal Lymphadenectomy (TEMLA) in preoperative staging of Non-Small-Cell Lung Cancer (NSCLC)
Material and methods: Operative technique included 5-8 cm collar incision in the neck, elevation of the sternal manubrium
with a special retractor, bilateral visualization of the laryngeal recurrent and vagus nerves and dissection of all mediastinal
nodal stations except of the pulmonary ligament nodes (station 9).
Results: 698 patients (577 men, 121 women), of mean age 62.8 (41-79) were operated on from 1.1.2004 to 31.1.2010,
including 501 squamous-cell carcinomas, 144 adenocarcinomas, 25 large cell carcinomas and 28 others. Mean operative
time was 128 min. (45 to 330 min) and 106.5 min. in the last 100 patients. 30-day mortality was 0.7 % (unrelated causes)
and morbidity 6.6%. The mean number of dissected nodes during TEMLA was 37.9 (15 to 85). Metastatic N2 and N3 nodes
were found in 152/698 (21.8%) and 26/698 patients (3.7%), respectively. Subsequent thoracotomy was performed in 445/513 patients (86.7%) after negative result of TEMLA. During thoracotomy, omitted N2 was found in 7/445 (1.6%) patients.
Sensitivity of TEMLA in discovery of metastatic N2-3 nodes was 96.2 %, specificity was 100%, accuracy was 99,0%,
Negative Predictive Value (NPV) was 98.7 % and Positive Predictive Value (PPV) was 100%.
Conclusions: TEMLA is a new minimally invasive surgical procedure providing unique possibility to perform very extensive,
bilateral mediastinal lymphadenectomy with very high diagnostic yield in staging of NSCLC
Pneumonol. Alergol. Pol. 2011; 79, 3: 196-20
Influence of material distribution and damping on the dynamic stability of Bernoulli-Euler beams
The study analyzed the influence of materials and different types of damping on the dynamic stability of the Bernoulli-Euler beam. Using the mode summation method and applying an orthogonal condition of eigenfunctions and describing the analyzed system with the Mathieu equation, the problem of dynamic stability was solved. By examining the influence of internal and external damping and damping in the beam supports, their influence on the regions of stability and instability of the solution to the Mathieu equation was determined
The “athlete’s heart” features in amateur male marathon runners
Background: Training on a professional level can lead to cardiac structural adaptations called the “athlete’s heart”. As marathon participation requires intense physical preparation, the question arises whether the features of “athlete’s heart” can also develop in recreational runners.Methods: The study included 34 males (mean age 40 ± 8 years) who underwent physical examination, a cardiopulmonary exercise test and echocardiographic examination (ECHO) before a marathon. ECHO results were compared with the sedentary control group, reference values for an adult male population and those for highly-trained athletes. Runners with abnormalities revealed by ECHO were referred for cardiac magnetic resonance imaging (CMR).Results: The mean training distance was 56.5 ± 19.7 km/week, peak oxygen uptake was 53.7 ± 6.9 mL/kg/min and the marathon finishing time was 3.7 ± 0.4 h. Compared to sedentary controls, amateur athletes presented larger atria, increased left ventricular (LV) wall thickness, larger LV mass and basal right ventricular (RV) inflow diameter (p < 0.05). When compared with ranges for the general adult population, 56% of participants showed increased left atrial volume, indexed to body surface area (LAVI), 56% right atrial area and interventricular septum thickness, while 47% had enlarged RV proximal outflow tract diameter. In 50% of cases, LAVI exceeded values reported for highly-trained athletes. Due to ECHO abnormalities, CMR was performed in 6 participants, which revealed hypertrophic cardiomyopathy in 1 runner.Conclusions: “Athlete’s heart” features occur in amateur marathon runners. In this group, ECHO reference values for highly-trained elite athletes should be considered, rather than those for the general population and even then LAVI can exceed the upper normal value
Influence of Salinity of Mixing Water Towards Physical and Mechanical Properties of High Strength Concrete
Dramatic population and economic growth result in increasing demand for concrete infrastructure, which leads to an increment of freshwater demand and a reduction of freshwater resources. however, freshwater is a finite resource, which means that freshwater will be used up someday in the future when freshwater demand keeps increasing while freshwater resources are limited. therefore, replacing freshwater with seawater in concrete blending seems potentially beneficial for maintaining the freshwater resources as well as advantageous alternatives to the construction work near the sea. there have been few experimental research on the effect of blending water salt content on the mechanical and physical characteristics of concrete, particularly high-strength concrete. therefore, a research study on the influence of salt concentration of blending water on the physical and mechanical properties of high-strength concrete is necessary. this study covered the blending water salinity, which varied from 17.5 g/l to 52.5 g/l and was determined on the physical and mechanical properties, including workability, density, compressive strength, and flexural strength. the test results indicate that the use of sea salt in blending water had a slight negative influence on both the workability and the density of high strength concrete. it also indicates that the use of sea salt in blending water had a positive influence on both the compressive strength and the flexural strength of high-strength concrete in an earlystage
Marshall Stability of Porous Asphalt Mixture Incorporating Kenaf Fiber
Porous asphalt mixture (PA), known as open-graded surfaces over a stone bed underneath,
allows water to go through. These factors can affect the porous asphalt mixture adhesive strength. The
high amount of course aggregate promotes the structure of air voids have certain impacts on the acoustic
properties of porous asphalt. The materials properties are consisting of both aggregate and bitumen
tests. This study also details out the aggregates sieve analysis test to develop new aggregate gradation for
PA. According to five ASEAN countries’ specifications, the sieve analysis test was done. The countries
included are Malaysia, Vietnam, Thailand, Singapore, and Indonesia. The test for the binder includes
the softening point, penetration, and ductility. This study also investigates the addition of kenaf fiber in
the mixture as an additive. Mechanical performance test for PA using Marshall Stability test to identify
the strength and the properties of the conventional PA with the addition of kenaf fiber compared to the
new gradation of PA incorporating kenaf fiber. From the results, the addition of 0.3% kenaf modified
PA improved the performance of PA in terms of Marshall Stability and volumetric properties
The Impact of Microwave Treatment on the Chemical Properties of Sewerage Sludge
Due to urbanization, the population in the major cities in Malaysia is approximately 72.8% of its total population. The increase of population density has directly increased the amount of sewerage sludge waste that poses threat to the environment. In line with the green initiatives, alternative method to develop good quality concrete material from sewerage sludge waste can be further explored. Traditionally, sewerage sludge waste is processed using incinerator that require high energy and it is time consuming. In this study, microwave heating which require less energy consumption and less time consuming is used for sewerage sludge preparation. Prior to heating process, sewerage sludge waste is over dried at 105◦C for 24 hours. Three types of microwave heating namely medium heating, medium high heating and high heating has been used. The chemical and physical properties microwaved sewerage sludge ash (MSSA) was tested using X-Ray Fluorescence (XRF), X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). Based on the result, the recommended temperature for the MSSA production for the concrete is High Mode Temperature. This is due to the result of MSSA for X-Ray Fluorescent test as its shows the highest in the content for pozzolanic element which are SiO2 and Fe2O3 that produce after the microwave burning process. The mineralogical composition and the crystalline phase of the High temperature MSSA due to X-Ray Diffraction test also shows high content of SiO2 as the major component as it is good for pozzolanic reaction in concrete. From the Scanning Electron Microscope test, it is observed that particle of High heated MSSA are slightly smaller than other temperature. Also, the densification occurs at High temperature MSSA. Hence, the optimal burning temperature mode for MSSA is High Mode temperatur
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