568 research outputs found
Effects of heating treatment on some of the physical properties of varnish layers applied on various wood species
The aim of the current study is to determine the effects of different heat treatment and varnish combination applications on some of the physical properties of wood materials sampled from limba (Terminalia superba), iroko (Chlorophora excelsa), ash (Fraxinus excelsior L.) and Anatolian chestnut (Castenea sativa Mill.) species. The heat treatment was applied at two levels (150 and 180°C) for both 3 and 6 h period. Once heat treatment was conducted, four types of varnish layers (cellulose lacquer, synthetic varnish, polyurethane varnish and water based varnish) were applied to the materials. After the treatments application, color, brightness and surface roughness of varnish film layers of the treated woods were measured. The effects of heat treatment and varnish combination applications on the earlier mentioned variables were analyzed according to the study design (factorial design with 4 (species) x 2 (heat) x 2 (duration) x 4 (varnish) = 64 experimental units). For significant analysis of variance (ANOVA) , Duncan mean separation test was performed to separate the interaction combinations. Results of the study indicated that surface roughness increased on wood samples for all four wood species treated with cellulose lacquer and synthetic varnish and across all heating treatments. However, surface roughness decreased for all wood species depending on heating temperature and time. As such, the value of brightness also decreased for all four wood species across all the treatment combinations. The results obtained from the upper surface of the enforcement process are thought to contribute to the national economy.Key words: Heating treatment, cellulose lacquer varnish, synthetic varnish, polyurethane varnish, water based varnish, surface roughness, brightness, color changes
Factors affecting pain and fatigue in females with chronic widespread pain
Purpose: This study was conducted to investigate factors related to pain intensity and global fatigue in females with Chronic Widespread Pain (CWP). Material and methods: One hundred four patients with CWP were included. The mean age was 40.28±10.82 years. Both Pain intensity and global fatigue were assessed using a Visual Analogue Scale (VAS). The Hospital Anxiety and Depression Scale was used to describe anxiety and depression symptoms. Three different questionnaires (leisure time activity, and physical activity at home, at work) were used to determine physical activity levels. Dorsal regression was used to analyze the data. Results: The anxiety score was the most common factor affecting pain intensity (p=0.003). On the other hand, a moderate level of physical activity at home (p=0.027), physical activity level at work (p=0.008), and the anxiety score (p=0.027) were significant factors affecting global fatigue. Conclusion: Our results show that anxiety is the most important factor affecting both pain and global fatigue in women with CWP. These results also support the idea that the characteristics of pain, fatigue and anxiety should be evaluated separately
Hamilton-Jacobi treatment of a non-relativistic particle on a curved space
In this paper a non-relativistic particle moving on a hypersurface in a
curved space and the multidimensional rotator are investigated using the
Hamilton-Jacobi formalism. The equivalence with the Dirac Hamiltonian formalism
is demonstrated in both Cartesian and curvilinear coordinates. The energy
spectrum of the multidimensional rotator is equal to that of a pure
Laplace-Beltrami operator with no additional constant arising from the
curvature of the sphere.Comment: 10 pages, LaTe
Examination of inclinations of the spine at childhood and adolescence
Background: Spine is a column that consists of consecutively lined up vertebras. It includes medulla spinalis. It contributes the motions of head, neck and body. Spine is not a straight column. There is a convexity towards the front of the spine (lordosis) at cervical and lumbar areas in adults and a convexity towards the back of the spine (kyphosis) at thoracic and sacral spine areas.
Materials and methods: In this study, lateral magnetic resonance images of 731 children between 1 and 16 years of age were examined and their cervical lordosis, thoracic kyphosis and lumbar lordosis angles were measured with Cobb method using ImageJ programme for every age group.
Results: The mean calculated cervical lordosis angles in 1–16-year-old children were found to be 20.51o ± 6.11o (minimum 17.96o ± 6.29o, maximum 23.50o ± ± 4.14o). It has been observed that cervical angle values decrease with age. The mean thoracic kyphosis angle measured was 28.71o ± 6.99o (minimum 24.55o ± ± 5.65o, maximum 30.44o ± 4.68o). Lumbar lordosis angle was 28.08o ± 7.39o (minimum 20.36o ± 6.59o, maximum 32.68o ± 6.03o). Thoracic kyphosis and lumbar lordosis angle values increased with age. In our study, a statistical differ- ence was found in increasing thoracic kyphosis angle between 1-year-old group and 14-year-old group. Statistical difference was also found in decreasing cervical lordosis angle value between 1-year-old group and 16-year-old group. When we compare our study results with literature values, cervical lordosis values were similar, but lumbar lordosis values were lower.
Conclusions: In summary, we think that knowing sagittal plane inclinations of the spine developing in childhood and adolescence will contribute to earlier de- termination of pathologies. We also hope that it will contribute to clinical stages and other studies in this field.
Modeling Surface Water Quality and Nutrient Correlation with Sediment Oxygen Demand at Dam Water Reservoirs
The work presented here is a model approach based on WASP8 (Water analysis simulation program) a water quality model simulated to represent contaminants at the surface and bottom sediments of Kurtboğazı dam reservoir in Ankara city. However, our water quality output variables: are temperature, nitrate, total phosphorus, total Kjeldahl nitrogen, dissolved oxygen, Chlorophyll a, and ammonia. To ensure the model represents the actual case at the reservoir, the results from the simulation model were calibrated using actual data from the Kurtboğazı dam site, the calibration utilizes statistical techniques. The first method was the goodness-of-fit, R2 between model variables and field data, and the results were in the range of 0.86 to 1.0 indicating excellent linear association. The second technique was the RE, the values of which obtained were less than 1, elaborating acceptable results. The dam reservoir Kurtboğazı had been affected by the negative impact arising from dissolved oxygen depletion in the hypolimnetic layer during stratification periods and that had been well documented. However, the processes of oxygen consumption at the sediment-water interface are still difficult to grasp conceptually and mainly linked to sediment oxygen depletion and the phenomena of sediment oxygen demand SOD. The novelty of this research work is the development of a quality model to predict the reactions of state variables that are occurring at the water body and how they interact with each other and their influence on the overall quality status of the Kurtboğazı reservoir, and the crucial factors influencing the depletion of oxygen at the water column; secondly, the effect of anoxic condition on the benthic flux and the impact of anoxia condition on the ratio of nitrogen to phosphorus ratio at the reservoir. It was evident from the results of calibration that the model successfully simulated the correlation of the parameters influencing the anoxic condition, and benthic flux and ratio shift from nitrogen-limited during the summer to phosphorus-limited at the beginning of winter
Characterizing the universal rigidity of generic frameworks
A framework is a graph and a map from its vertices to E^d (for some d). A
framework is universally rigid if any framework in any dimension with the same
graph and edge lengths is a Euclidean image of it. We show that a generic
universally rigid framework has a positive semi-definite stress matrix of
maximal rank. Connelly showed that the existence of such a positive
semi-definite stress matrix is sufficient for universal rigidity, so this
provides a characterization of universal rigidity for generic frameworks. We
also extend our argument to give a new result on the genericity of strict
complementarity in semidefinite programming.Comment: 18 pages, v2: updates throughout; v3: published versio
Six-fold in-plane magnetic anisotropy in Co-implanted ZnO (0001)
Magnetic anisotropies of Co-implanted ZnO (0001) films grown on single-crystalline Al2O3 (11 2- 0) substrates have been studied by ferromagnetic resonance (FMR) technique for different cobalt implantation doses. The FMR data show that the easy and hard axes have a periodicity of 60° in the film plane, in agreement with the hexagonal structure of the ZnO films. This six-fold in-plane magnetic anisotropy, which is observed for the first time in ZnO-based diluted magnetic semiconductors, is attributed to the substitution of cobalt on Zn sites in the ZnO structure, and a clear indication for long range ferromagnetic ordering between substitutional cobalt ions in the single-crystalline ZnO films. © 2009 American Institute of Physics
Associated Charm Production in Neutrino-Nucleus Interactions
In this paper a search for associated charm production both in neutral and
charged current -nucleus interactions is presented. The improvement of
automatic scanning systems in the {CHORUS} experiment allows an efficient
search to be performed in emulsion for short-lived particles. Hence a search
for rare processes, like the associated charm production, becomes possible
through the observation of the double charm-decay topology with a very low
background. About 130,000 interactions located in the emulsion target
have been analysed. Three events with two charm decays have been observed in
the neutral-current sample with an estimated background of 0.180.05. The
relative rate of the associated charm cross-section in deep inelastic
interactions, has been
measured. One event with two charm decays has been observed in charged-current
interactions with an estimated background of 0.180.06 and the
upper limit on associated charm production in charged-current interactions at
90% C.L. has been found to be .Comment: 10 pages, 4 figure
Leading order analysis of neutrino induced dimuon events in the CHORUS experiment
We present a leading order QCD analysis of a sample of neutrino induced
charged-current events with two muons in the final state originating in the
lead-scintillating fibre calorimeter of the CHORUS detector. The results are
based on a sample of 8910 neutrino and 430 antineutrino induced opposite-sign
dimuon events collected during the exposure of the detector to the CERN Wide
Band Neutrino Beam between 1995 and 1998. % with GeV
and GeV collected %between 1995 and 1998. The analysis yields a
value of the charm quark mass of \mc = (1.26\pm 0.16 \pm 0.09) \GeVcc and a
value of the ratio of the strange to non-strange sea in the nucleon of , improving the results obtained in similar analyses
by previous experiments.Comment: Submitted to Nuclear Physics
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