In this study, a simulation of the MTR-22MW reactor and a study
of standard and mixed fuel combustion using the Codes GETERA
and MCNP5.
The Results of the simulation showed that the operation time of the
reactor in the case of standard fuel is 274 days and if the use of
mixed fuel is 135 days.
The research was carried out in the fields of Akar plain in Tartous
province during two seasons (2013, 2014) to study the effect the three
multiplication methods (Slips as control, Seedling, Cut-seed tuber) on
growth and yield of two locally sprea
d sweet potato varieties. The
experimental design was a randomized complete block with three
replications. Data were analyzed using the statistical program GenStat 12.
In this study, the effect of different concentrations of sodium chloride
(NaCl) (0, 50, 100, 150 mM) on some physiological characteristics and some
growth indicators of SO4 grape rootstock propagated in vitro was studied at the
laboratories of Gen
eral Commission for Scientific Agricultural Research
(GCSAR), Damascus/Syria. Results indicated that the increase of NaCl
concentration up to 100 mM in culture medium led to reduce the growth
indicators (survival plants, average of the plant length and average number of
buds) with significant differences when compared with the control plants after
4 weeks from culturing on multiplication media, while treatment with 150 mM
of sodium chloride led to death of all plants. Using the concentrations 50 and
100 mM of NaCl also caused decreasing the total chlorophyll content in the
leaves.
This current study was carried out on B41 grape rootstock
micropropagated in vitro at the General Commission for Scientific Agricultural
Research (GCSAR), Syria to study the effect of different concentrations of
sodium chloride on the multiplicati
on and rooting stages. The results showed
that the highest average of survival plants (98%), the number of new buds
(8.43) and plant length (8.58 cm) were obtained in the control treatment after 4
weeks from multiplication stage. The treatment with 50 mM of sodium chloride
led to reduce the multiplication rates with significant differences, while the
lowest plant multiplication had occurred with 100 mM of sodium chloride and
no survival plants were remained by the treatment with 150 mM of sodium
chloride during multiplication stage. The highest rooting rates (% 85.30), the
number of roots (4.67) and root length (6.28 cm) were also obtained in the
control treatment after 4 weeks from rooting stage. The treatment with 50 mM
of sodium chloride led to reduce the rooting process with significant
differences. The lowest rooting results were observed with 100 mM of sodium
chloride and no rooting rate was observed when plants were treated with 150
mM of sodium chloride.
The MCNP4C2 Monte Carlo code was used to model the Egyptian Second
research reactor in this paper, to calculate the effective multiplication factor
keff, distribution of the thermal and fast neutron fluxes and power in reactor
core with two type o
f fuels: standard and mixed. The values of the keff were
1.21842 and 1.05272, the maximum thermal flux were 2.975x10+14 and
3.352x10+14 n/cm2s, and the maximum fast flux was 2.950x10+14 and 2.389x10+14
n/cm2s for standard and mixed fuels respectively. The results showed good
agreements with previous results available in the literature.
Nuclear reactors depend on nuclear fission phenomenon in their work. The
effective multiplication factor depends on the number of neutrons in two
successive generations and it usually controled in the reactor by using control
rods. In this paper،
calculations of the effective multiplication factor for the
highly safe new generation VVER- 640 type reactor is conducted in two
methods: analytic method using the Mathcad program and the GETERA code.
The effective multiplication factor for the first method was 1.3430 and it was
1.3477 using the GETERA cod. Good agreement was noticed between the two
methods.
معامل التضاعف الفعال
Effective multiplication factor
معامل الانشطار السريع
احتمالية الهروب من الامتصاص الرنيني
معامل الاستفادة من النترونات الحرارية
معامل المكوث السريع
معامل المكوث الحراري
Fast fission factor
Probability escaping from resonance absorption
Utilization factor of thermal neutrons
Fast remaining factor
Thermal staying factor
المزيد..
This current study was conducted on gardenia plant (Gardenia
jasminoides.L.) cv. ellis. which was micropropagated in vitro to study the effect
of some plant growth regulators on multiplication and rooting, for the aim of
developing a complete in v
itro microprpagation system of the studied cv.
Results demonstrated that, the best medium for in vitro micropropagation of
the studied cv. was MS medium supplemented with 1 mg/L BA + 0.1 mg/L IBA
with a multiplication rate of 5.33 new shoots, with average shoot height of 4.73
cm, and average leaf number of 4.36. These shoots were then transferred to a
rooting media containing a half-strength of the multiplication basal media with
NAA at a concentration of 1mg/L which resulted in highest rooting efficiency of
97% with average root number of 9.67, and average root length of 5.35 cm, and
average stem length of 9.80 cm, and average leaf number of 5.07. Increasing
NAA concentration in rooting media to 1.5 mg/L resulted in increasing root
length average to 6.28 cm with significant difference in comparison to the
previous treatment. Rooted Plantlets were acclimatized gradually in a growth
room conditions to ex vitro conditions with 85 % efficiency.
In vitro rooting was significantly increased by adding indolebutyric
acid (IBA) to medium and rooting was improved by adding ١,٠ g/L activated
charcoal or ٠,١ g/L polyvinylpyrrolidone (PVP). Indoleacetic acid (IAA) (٠,٠ to
٤,٠ mg/L) was not effect
ive for rooting except when used with ٠,١ g/L PVP. A
٩٥٪ survival was achieved when plants were acclimatized ex vitro. Such
procedures could help significantly in clonally propagating bitter almond and
conserving its germplasm.
