10,376 research outputs found
On the implications of a dilaton in gauge theory
Some recent work on the implications of a dilaton in 4d gauge theories are
revisited. In part I of this paper we see how an effective dilaton coupling to
gauge kinetic term provides a simple attractive mechanism to generate
confinement. In particular, we put emphasis on the derivation of confining
analytical solutions and look into the problem how dilaton degrees of freedom
modify Coulom potential and when a confining phase occurs. In part II, we solve
the semi-relativistic wave equation, for Dick interquark potential using the
Shifted l-expansion technique (SLET) in the heavy quarkonium sector. The
results of this phenomenological analysis proves that these effective theories
can be relevant to model quark confinement and may shed some light on
confinement mechanism.Comment: 8 pages. Talk given at CTP Symposium on Supersymmetry at LHC:
Theoretical and Experimental Prospectives, Cairo, Egypt, 11-14 Mar 200
Study of heterosis in single-cross hybrids of sunflower
This study was conducted to estimate the genetic variability and heterosis of 40 F1 hybrids of sunflower for seed yield and its components over two seasons (summer and winter) in 2007 at Sennar Research Station Farm in central Sudan. The plant material consisted of 14 sunflower parents (4 females and 10 males) and their 40 F1-hybrids. The experiment was arranged in a randomized complete block design with three replicates. The traits measured were days to 50% flowering, plant height, head diameter, number of seeds per head, one thousand seed weight and seed yield. Hybrids showed high genetic variability for all traits studied than their parents which suggested some degree of hybrid vigor. The direction and magnitude of heterosis varied from cross to cross. Over two seasons, the average mid-parent heterosis in preferred direction and magnitude depicted that the hybrid SA2 x SR41 followed by SA3 x SR41 for days to flowering, SA1 x SR14 for plant height, SA2 x SR14 for head diameter, SA2 x SR13 followed by SA3 x SR13 for number of seeds per head, and SA3 x SR7 for one thousand seed weight. With regard to seed yield, the best hybrids with positive average heterosis were SA3 x SR41 (53.42%), SA4 x SR45 (52.75%), SA4 x SR1 (52.25%) and SA3 x SR10 (40.63%) which also combined with high seed yield of 1581 kg/ha, 1479 kg/ha, 1474 kg/ha, and 1457 kg/ha, respectively. These hybrids (involving the female line SA3 or SA4 and the male lines (SR10, SR13, SR41 and SR45) can be used in our breeding program in an attempt to develop local sunflower hybrid (s) with high seed yield and other important agronomic traits and for testing their yield potential and stability across locations and seasons.
أجريت هذه الدراسة بهدف تقدير التباين الوراثي و قوة الهجن للإنتاجية ومكوناتها لأربعين هجين مفرد من محصول زهرة الشمس، نتجت من تهجين أربعة أمهات ذات عقم ذكرى سايتوبلازمى مع عشرة آباء معيدة للخصوبة. أجريت التجربة بمحطة بحوث سنار فى وسط السودان بالقطاع المروي لموسين (صيف وشتاء2007). أستخدم تصميم القطاعات العشوائية الكاملة بثلاثة مكررات. كانت الصفات المدروسة هى عدد الايام حتى 50% إزهار، طول النبات، قطر القرص، عدد البذور بالقرص، وزن الآلف حبة، وانتاج البذور. أظهرت النتائج فروقات معنوية لكل الصفات في الموسمين مع تفوق الهجن وتباينها وراثياً مقارنة بالآباء. وفي التحليل المشترك لحساب قوة الهجين لكل الصفات كنسبة زيادة أو نقصان من متوسط الأبويين، ظهر أنّ الهــجينينSA2 x SR41 وSA3 x SR 41 هما الأفضل للإزهار والنضج المبكر، الهجين SA1 x SR14 لطول النبات، الهـجين SA2 x SR14 لقطر القرص ، الهجينين SA2 x SR13 و SA3 x SR13 لعدد البذور بالقرص، الهجين SA3 x SR7 لوزن الألف بذرة. أما بخصوص إنتاجية البذور أظهرت بعض الهجن نسبة قوة هجين موجبة SA3 x SR41 ) (53.42%، (52.73% ) SA4 x SR45، SA4 x SR1 (52.25%)و SA3 x SR10 ((40.63% وإنتاجية بذور تقدر بـ 1581 كيلوجرام للهكتار، 1479 كيلوجرام للهكتار، 1474 كيلوجرام للهكتار و1459 كيلوجرام للهكتار علي التوالي. ويستنتج من هذه الدراسة ان الهجن التي يدخل في تركبيها الأم SA3 أو الأم SA4 مع الآباء SR41 ، SR45، SR13 و SR10 هى هجن متفوقة لإنتاجية البذور والصفات الأخرى ، ويمكن استخدام تلك الأمهات والآباء في تطوير هجن محلية مفردة من محصول الزهرة واختبار ثبات إنتاجيتها عبر المواسم والمواقع المختلفة
Quantum Criticality in Dimerized Spin Ladders
We analyze a possibility of quantum criticality (gaplessness) in dimerized
antiferromagnetic two- and three-leg spin-1/2 ladders. Contrary to earlier
studies of these models, we examine different dimerization patterns in the
ladder. We find that ladders with the columnar dimerization order have lower
zero-temperature energies and they are always gapped. For the staggered
dimerization order, we find the quantum critical lines, in agreement with
earlier analyses. The bond mean-field theory we apply, demonstrates its
quantitative accuracy and agrees with available numerical results. We conclude
that unless some mechanism for locking dimerization into the energetically less
favorable staggered configuration is provided, the dimerized ladders do not
order into the phase where the quantum criticality occurs.Comment: 7 pages, 9 figure
Numerical solution and spectrum of boundary-domain integral equation for the Neumann BVP with variable coefficient
This is the post-print version of the Article. The official published version can be accessed from the link below - Copyright @ 2012 Taylor & Francis.In this paper, a numerical implementation of a direct united boundary-domain integral equation (BDIE) related to the Neumann boundary value problem for a scalar elliptic partial differential equation with a variable coefficient is discussed. The BDIE is reduced to a uniquely solvable one by adding an appropriate perturbation operator. The mesh-based discretization of the BDIEs with quadrilateral domain elements leads to a system of linear algebraic equations (discretized BDIE). Then, the system is solved by LU decomposition and Neumann iterations. Convergence of the iterative method is discussed in relation to the distribution of eigenvalues of the corresponding discrete operators calculated numerically.The work was supported by the grant EP/H020497/1 "Mathematical analysis of localised boundary-domain integral equations for BVPs with variable coefficients" of the EPSRC, UK
EEG pattern for stress condition during listening rock music and binaural beat sound
Music has a great effect on human brain and brainwaves. It is already proven
that listening to music such as binaural beat sound and rock music increases
the beta band power that is associated to increase the stress condition during
listening. This research were conducted to determine the EEG pattern for
stress condition during listening binaural beat sound and rock music. The
research were conducted due to there is no previous research that conduct
an experiment related binaural beat during listening. The previous researcher
only focus on the effect of binaural beat after the listening. Experiment were
conducted on 5 subjects which are 3 female and 2 male and the data of
brainwaves of the samples were collected. The data collected were focused
only on Alpha band and Beta band which only exist when someone are in
awake state. The data were collected by using Emotiv Insight 5-Channel EEG
Mobile set which consist of the Emotiv Insight headset, the Universal USB
Receiver and the Emotiv Pure EEG software. The data were in power spectral
density (PSD) form and it were analyzed by using SPSS software. In SPSS
software, the data were analyzed to find the mean, standard deviation and the
distribution. From the analysis and discussion, the hypothesis of this research
are proven as the beta band are increasing and higher than alpha band. As for
the recommendation, the next researcher could increase the number of subject
for experimental and the songs also recommended to be divided based on
subject song preferences
Effect of nitrogen and phosphorus on growth and yield of irrigated sunflower (Helianthus annuus L.)*
Experiments were conducted in winter (2000 2001) and summer (2001) seasons at Elrahad Research Station to investigate the influe- nce of four levels of nitrogen and two levels of phosphorus on growth characters and seed yield of two sunflower cultivars, viz Rodio and Hysun 33. Experiments were arranged in a randomized complete block design with four replications. Rodio and Hysun 33 varied in their growth characters. Differences between the two cultivars. Were highly significant for plant height, leaf area index, days to 50% flowering, days to maturity, head diameter, number of seeds per head, 1000-seed weight and empty seeds percentage. The two cultivars were siY1ificantly different in their seed yield. Nitrogen application significantly increased all growth characters and seed yield of the two cultivars, in both seasons, however, it decreased days to 50% flowering and days to maturity. Nitrogen fertilizer had no significant effect on empty seeds percentage. Phosphorus application signific- antly increased leaf area index, head diameter, number of seeds per head and 1000-seed weight. However, plant height, days to maturity and percentage of empty seeds were not affected. Application of phosphorus had no significant effect on seed yield
A new degree six modified chordal ring network topology
The performance of a parallel or distributed network depends on the design of its interconnection topology. One good network interconnection topology that has been the focus of various researchers is the chordal ring. In this paper, a new degree six modified chordal ring is presented, the optimised degree six 3-modified chordal ring (CHR6o3), with the aim of comparing its performance parameters in terms of optimal diameter and optimal average path length to existing degree six chordal rings. Formulae to generate the data for each different chordal ring were derived from its corresponding tree visualisation or used from previous work. Network sizes tested were from 1200 to 12000 nodes. Large networks of CHR6o3 were shown to perform better than those of previous degree six chordal rings. This gives CHR6o3 an added advantage for its implementation in large distributive networks, such as Fibre to the Home (FTTH) networks, since it offers redundancies at higher network layers
Open circuit fault diagnosis technique for inverter switches and gate drive malfunction
Open circuit faults (OCFs) in voltage source inverters (VSIs) can significantly affect their performance and reliability. In this paper, a novel fault diagnosis technique (FDT)is presented for the detection and classification of two types of OCFs in VSIs: gate drive malfunction (GDM) and open switch fault (OSF). the effect of these OCFs on the output current of the VSI is analysed, this shows that they can be identified and distinguished using the average and root mean square (RMS) ratio of the current parameters. The proposed FDT is simple to implement and can identify switch faults with quick response, without the need for additional equipment. In this work the authors adopted the ensemble bagged tree classification method to detect and classify the GDM and OSF, the results show the credibility of the proposed technique in identifying different open circuit faults
Development and implementation of two-stage boost converter for single-phase inverter without transformer for PV systems
This paper offers a two-stage boost converter for a single-phase inverter without transformer for PV systems. Each stage of the converter is separately controlled by a pulse width modulated signal. A Simulink model of the converter using efficient voltage control topology is developed. The proposed circuit performance characteristics are explained and the obtained simulation results are confirmed through the applied experiments. Moreover, this paper has examined the control circuit of a single-phase inverter that delivers a pure sine wave with an output voltage that has the identical value and frequency as a grid voltage. A microcontroller supported an innovative technology is utilized to come up with a sine wave with fewer harmonics, much less price and an easier outline. A sinusoidal pulse width modulation (SPWM) technique is used by a microcontroller. The developed inverter integrated with the two-stage boost converter has improved the output waveform quality and controlled the dead time as it decreased to 63 µs compared to 180 µs in conventional methods. The system design is reproduced in Proteus and PSIM Software to analyze its operation principle that is confirmed practically
- …