scholarly journals Variability of needle morpho-anatomy of natural Pinus heldreichii populations from Scardo-Pindic mountains

Genetika ◽  
2019 ◽  
Vol 51 (3) ◽  
pp. 1175-1184
Author(s):  
Biljana Nikolic ◽  
Zorica Mitic ◽  
Srdjan Bojovic ◽  
Vlado Matevski ◽  
Zoran Krivosej ◽  
...  
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Light Microscope ◽  
Needle Length ◽  
Mean Values ◽  
Resin Ducts ◽  
Resin Duct ◽  
Dinaric Mountains ◽  
The Mean ◽  
Anatomical Properties

Eight morpho-anatomical properties of two-year-old needles of Pinus heldreichii (Bosnian pine) from the Scardo-Pindic mountain massif in Serbia (Kosovo, Mt. Osljak) and North Macedonia (Mt. Galicica) were investigated. All measured characteristics, except for needle length, were inspected on mid-needle cross-section. Cross-sections were obtained with razorblade, while measurements were performed with Leica-Gallen III light microscope. The mean values of the analyzed characters were as follows: 5.91 cm (needle length), 1.35 mm (needle width), 0.85 mm (needle thickness), 25.05 ?m (cuticle + epidermis thickness), 69.90 ?m (height of hypodermal cells), 21.76 ?m (resin duct diameter), 3.4 (number of hypodermis layers), and 3.6 (number of resin ducts). P. heldreichii needles also had 2-5 hypodermis layers and 0-12 resin ducts. The highest variation was in the number of resin ducts (CV=27%). In comparison with previously investigated needles from the Dinaric mountains, P. heldreichii needles from the Scardo-Pindic massif were shorter and had a thicker layer of hypodermis. PCA and CA visualize partial segregation of P. heldreichii populations between the two mountain massifs.

scholarly journals Quantitative Ausmessung des Brom-Affinitätskontinuums und Bestimmung der Detachment-und Attachment-Querschnitte

1970 ◽  
Vol 25 (11) ◽  
pp. 1617-1626 ◽  
Author(s):  
H. Frank ◽  
M. Neiger ◽  
H.-P. Popp
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Electron Affinity ◽  
Elastic Cross Section ◽  
Electron Atom ◽  
Intensity Measurements ◽  
Long Wave ◽  
The Mean ◽  
Intense Electron

Abstract A wall stabilized low-current cylindric arc was used to produce the radiation of the negative Bromine-ions. The radiation consists of an affinity-continuum with a long-wave threshold of 3682 Å, yielding an electron affinity for Bromine of 3.366 eV, and of an intense electron-atom Bremsstrahlung in the visible. Intensity measurements of the continua allow the determination of the photo-detachment-and attachment-cross-sections of Bromine and also the determination of the mean elastic cross-section of electrons against Bromine atoms.

The determination of the cross sections for the reactions 27 Al( n , α ) and 56 Fe( n , p ) for 14 MeV neutrons by an absolute method

1966 ◽  
Vol 292 (1429) ◽  
pp. 180-192 ◽  
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Standard Error ◽  
Particle Method ◽  
Systematic Errors ◽  
Aluminium Foil ◽  
The Mean ◽  
The Cross ◽  
Experimental Values

Measurements of the cross sections for the reactions 27 Al( n , α ) 24 Na and 56 Fe( n, p ) 56 Mn for neutrons of energy 13.5 ± 0.1 MeV have been made by a radioactivation method. The neutron flux was determined by a variant of the 'associated particle’ method, in which the α -particles produced concurrently with the neutrons from the D + T reaction were estimated in terms of the volume of helium which accumulated when they were brought to rest in an aluminium foil. Cross section values obtained at 13.5 MeV were: for 27 Al( n , α ): 118.1 ± 6.0 mb : for 56 Fe( n, p ): 106.7 ± 4.7 mb. The errors quoted include both the standard error on the mean of the experimental values and an estimate of possible residual systematic errors. The excitation functions for both reactions in the energy region 13.5 to 14.8 MeV have also been investigated, in order to provide secondary cross section values over this range of energies. At 14.8 MeV the values found were: 27 Al( n , α )103.6 ± 5.5 mb; 56 Fe( n, p )96.7 ± 4.5 mb.

scholarly journals Intercomparison of slant column measurements of NO<sub>2</sub> and O<sub>4</sub> by MAX-DOAS and zenith-sky UV and visible spectrometers

2010 ◽  
Vol 3 (6) ◽  
pp. 1629-1646 ◽  
Author(s):  
H. K. Roscoe ◽  
M. Van Roozendael ◽  
C. Fayt ◽  
A. du Piesanie ◽  
N. Abuhassan ◽  
...  
Keyword(s):  
Cross Sections ◽  
Measuring Instruments ◽  
Mean Values ◽  
Straight Line ◽  
Tropospheric No2 ◽  
The Mean ◽  
Almost All ◽  
Level Of Agreement ◽  
Selection Of ◽  
Differential Spectroscopy

Abstract. In June 2009, 22 spectrometers from 14 institutes measured tropospheric and stratospheric NO2 from the ground for more than 11 days during the Cabauw Intercomparison Campaign of Nitrogen Dioxide measuring Instruments (CINDI), at Cabauw, NL (51.97° N, 4.93° E). All visible instruments used a common wavelength range and set of cross sections for the spectral analysis. Most of the instruments were of the multi-axis design with analysis by differential spectroscopy software (MAX-DOAS), whose non-zenith slant columns were compared by examining slopes of their least-squares straight line fits to mean values of a selection of instruments, after taking 30-min averages. Zenith slant columns near twilight were compared by fits to interpolated values of a reference instrument, then normalised by the mean of the slopes of the best instruments. For visible MAX-DOAS instruments, the means of the fitted slopes for NO2 and O4 of all except one instrument were within 10% of unity at almost all non-zenith elevations, and most were within 5%. Values for UV MAX-DOAS instruments were almost as good, being 12% and 7%, respectively. For visible instruments at zenith near twilight, the means of the fitted slopes of all instruments were within 5% of unity. This level of agreement is as good as that of previous intercomparisons, despite the site not being ideal for zenith twilight measurements. It bodes well for the future of measurements of tropospheric NO2, as previous intercomparisons were only for zenith instruments focussing on stratospheric NO2, with their longer heritage.

scholarly journals Anatomical study of the leaves and petioles of scab resistant and susceptible apple cultivars

2005 ◽  
Vol 11 (3) ◽  
Author(s):  
M. Tóth ◽  
P. Gracza
Keyword(s):  
Cross Sections ◽  
Light Microscope ◽  
Leaf Blade ◽  
Anatomical Study ◽  
Scab Resistance ◽  
Preliminary Results ◽  
Apple Cultivars ◽  
Anatomical Properties ◽  
Scanning Electron ◽  
Shape And Size

Anatomic studies have been performed on the leaf blade, petiole and annual shoot on six apple cultivars by means of scanning electron as well as light microscope. Four of the cultivars examined are resistant to scab (Florina, Freedom, MR-10, MR-11), whereas two of them are susceptible (Jonathan and Idared). Preliminary results suggest that differences in the width of cross sections of leaf blades, in hairyness, in the shape and size of epidermal cells, moreover, in the cross sections of petioles and shoots are considerable. Some of the anatomical properties seem to be correlated with scab resistance or susceptility of the respective cultivars. Therefore, further studies extending to other cultivars may corroborate our claims to find causal relations between anatomical traits of the leaves and disease, especially scab resistance of apple cultivars.

scholarly journals Deexcitation Probabilities of Ne(3P2) by Kr for the Case E << D

1970 ◽  
Vol 24 ◽  
pp. 45-48
Author(s):  
Deba Bahadur Khadka
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Chemical Society ◽  
Ionization Cross ◽  
Penning Ionization ◽  
Collisional Energy ◽  
Theoretical Investigations ◽  
Probability Calculation ◽  
The Mean ◽  
Made In

The deexcitation probability calculation of the total Penning ionization cross section for Ne(3P2) by Kr has been made in the region of the collisional energy from 18.5 to 38.1 meV. Considering the magnitude of the mean collisional energy with respect to D, the application of the analysis in the case E >> D is expected to be more appropriate than in the case E << D. Theoretical investigations of Ne(3P2) by Kr for the case E >> D are also needed.Keywords: metastable atoms, resonance atoms, deexcitation cross sections, pulse radiolysis, impact parameter.DOI: 10.3126/jncs.v24i0.2390Journal of Nepal Chemical Society Vol.24 Page 45-48

scholarly journals On the ‘high spots’ of fundamental sloshing modes in a trough

2010 ◽  
Vol 467 (2129) ◽  
pp. 1491-1502 ◽  
Author(s):  
T. Kulczycki ◽  
N. Kuznetsov
Keyword(s):  
Boundary Condition ◽  
Free Surface ◽  
Eigenvalue Problem ◽  
Cross Section ◽  
Cross Sections ◽  
Orthogonal Projection ◽  
Free Oscillations ◽  
Uniform Cross Section ◽  
The Mean ◽  
The One

We study an eigenvalue problem with a spectral parameter in a boundary condition. The problem describes sloshing of a heavy liquid in a container, which means that the unknowns are the frequencies and modes of the liquid’s free oscillations. The question of ‘high spots’ (the points on the mean free surface, where its elevation attains the maximum and minimum values) is considered for fundamental sloshing modes in troughs of uniform cross section. For troughs, whose cross sections are such that the horizontal, top interval is the one-to-one orthogonal projection of the bottom, the following result is obtained: any fundamental eigenfunction attains its maximum and minimum values only on the boundary of the rectangular free surface of the trough.

scholarly journals The Sonic Resonance Method and the Impulse Excitation Technique: A Comparison Study

2021 ◽  
Vol 11 (22) ◽  
pp. 10802
Author(s):  
Tomáš Húlan ◽  
Filip Obert ◽  
Ján Ondruška ◽  
Igor Štubňa ◽  
Anton Trník
Keyword(s):  
Cross Section ◽  
Rectangular Cross Section ◽  
Circular Cross Section ◽  
Resonance Method ◽  
Resonant Frequencies ◽  
Mean Values ◽  
Impulse Excitation ◽  
The Mean ◽  
The Relationship ◽  
Resonant Method

In this study, resonant frequencies of flexurally vibrating samples were measured using the sonic resonant method (SRM) and the impulse excitation technique (IET) to assess the equivalency of these two methods. Samples were made from different materials and with two shapes (prism with rectangular cross-section and cylinder with circular cross-section). The mean values and standard deviations of the resonant frequencies were compared using the t-test and the F-test. The tests showed an equivalency of both methods in measuring resonant frequency. The differences between the values measured using SRM and IET were not significant. Graphically, the relationship between the resonant frequencies is a line with a slope of 0.9993 ≈ 1.

scholarly journals Intercomparison of slant column measurements of NO<sub>2</sub> and O<sub>4</sub> by MAX-DOAS and zenith-sky UV and visible spectrometers

2010 ◽  
Vol 3 (4) ◽  
pp. 3383-3423 ◽  
Author(s):  
H. K. Roscoe ◽  
M. Van Roozendael ◽  
C. Fayt ◽  
A. du Piesanie ◽  
N. Abuhassan ◽  
...  
Keyword(s):  
Cross Sections ◽  
Measuring Instruments ◽  
Mean Values ◽  
Straight Line ◽  
Tropospheric No2 ◽  
The Mean ◽  
Almost All ◽  
Level Of Agreement ◽  
Selection Of ◽  
Differential Spectroscopy

Abstract. In June 2009, 22 spectrometers from 14 institutes measured tropospheric and stratospheric NO2 from the ground for more than 11 days during the Cabauw Intercomparison campaign of Nitrogen Dioxide measuring Instruments (CINDI), at Cabauw, NL (51.97° N, 4.93° E). All visible instruments used a common wavelength range and set of cross sections for the spectral analysis. Most of the instruments were of the multi-axis design with analysis by differential spectroscopy software (MAX-DOAS), whose non-zenith slant columns were compared by examining slopes of their least-squares straight line fits to mean values of a selection of instruments, after taking 30-min averages. Zenith slant columns near twilight were compared by fits to interpolated values of a reference instrument, then normalised by the mean of the slopes of the best instruments. For visible MAX-DOAS instruments, the means of the fitted slopes for NO2 and O4 of all except one instrument were within 10% of unity at almost all non-zenith elevations, and most were within 5%. Values for UV MAX-DOAS instruments were almost as good, being 12% and 7%, respectively. For visible instruments at zenith near twilight, the means of the fitted slopes of all instruments were within 5% of unity. This level of agreement is as good as that of previous intercomparisons, despite the site not being ideal for zenith twilight measurements. It bodes well for the future of measurements of tropospheric NO2, as previous intercomparisons were only for zenith instruments focussing on stratospheric NO2, with their longer heritage.

EVAPORATION NEUTRONS FROM COSMIC RAY NUCLEAR INTERACTIONS IN VARIOUS ELEMENTS

1956 ◽  
Vol 34 (3) ◽  
pp. 288-303 ◽  
Author(s):  
K. W. Geiger
Keyword(s):  
Cosmic Rays ◽  
Cross Section ◽  
Cross Sections ◽  
Boron Trifluoride ◽  
Cosmic Ray ◽  
Atomic Weight ◽  
Nuclear Interactions ◽  
The Mean ◽  
Neutron Multiplicities ◽  
Interaction Cross Sections

Production of evaporation neutrons from nuclear interactions by cosmic rays is investigated in C, Al, Fe, Cu, Pb, and Bi. Boron trifluoride counters in a paraffin moderator in which the element under study is placed serve to detect the evaporation neutrons. A cosmic ray telescope allows the consideration of ionizing neutron-producing particles separately and it is found that of the total neutrons 14.6% are produced by ionizing particles. The mean neutron multiplicities are worked out and they show an increase with the two-thirds power of the atomic weight of the element in which the interactions take place. Also, the rate of interactions is calculated and this gives the relative interaction cross-sections which are found to increase slightly more with atomic weight than expected if the cross-section is geometric. An estimate of the intensity of the N-component is made and discussed in connection with measurements published by other authors.

Aerodynamic characteristics of trains on a viaduct with non-uniform cross-section under crosswinds by wind tunnel tests

2021 ◽  
pp. 136943322098609
Author(s):  
Kehui Yu ◽  
Xuhui He ◽  
Chenzhi Cai ◽  
Lei Yan ◽  
Yunfeng Zou
Keyword(s):  
Wind Speed ◽  
Wind Tunnel ◽  
Cross Section ◽  
Cross Sections ◽  
Aerodynamic Characteristics ◽  
Fluctuating Pressure ◽  
Pressure Coefficients ◽  
Mean Wind Speed ◽  
Bridge Girder ◽  
The Mean

This paper focuses on the aerodynamic characteristics of trains on a non-uniform double-track railway bridge under crosswinds through a scaled 1:40 sectional model wind tunnel test. Pressure measurements of five cross-sections of two types of trains, one with round roof and one with blunt roof, at the upstream and downstream tracks of the bridge were conducted under crosswinds with wind attack angles between −12° and 12°. The mean wind speed and turbulence intensity profiles around the windward surface of the train in the downwind and upward directions were also measured using cobra probe to obtain the boundary layer above the bridge surface. The results show that the shapes of train and bridge, as well as the wind attack angle, affect the aerodynamic characteristic of the train on the non-uniform bridge girder. The mean and fluctuating pressure coefficients are similar for all five cross-sections of the trains while the train is at the upstream track. However, when the train is at the downstream track, the extreme mean and fluctuating pressure coefficients around the windward and top surfaces of each cross-section on the train are different. At the downstream track, the mean wind speed profile and the turbulence intensity profile around the top of the train vary dramatically due to the separation flow caused by the leading edge of the bridge girder.

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