In this research a mathematical model for solar store is organized in which save the heat solar energy is saved for different purposes such as electrical energy generation , heating , or bio-energy fermentation and many other uses . This model includ
es a mixture of heat store substances such as sand , graphite , sea water , the dark cement rocks . The equation of the model was arranged , and solved by using variable values for the shape , and the dimensions of the reservoir and the percentage of the materials in the mixture by using a computer program through which the Matlab program was based on , and was practiced on two kinds of heats store mixtures . The results was converted in to geometric curves through which the comparison can be made between the two mixtures . The results showed that using a mixture of the sea water and dark cement rocks model gave better results .
تتعرض الليبيدات كما تتعرض أغلب مكونات الدقيق إلى جملة من التغيرات أثناء التخزين ينعكس ذلك على الخصائص الفزيائية لللعجين وعلى نوعية الخبز الناتج
The research aims to examine the relationship between
organizational culture on the one hand, and between knowledge
management practices in Tishreen University, on the other hand, where
the researcher distributed a questionnaire to a sample of the
colleges in
the University of Tishreen reached (205) questionnaire was recovered
(222) to identify them, it was good of them use (158) questionnaire. To
test the relationship, the researcher used the Student T test for one sample,
as well as the Pearson correlation coefficient.
According to the importance of economic solar ponds in domestic and industrial
daily practical applications and its international widespread, this created the basis of an
experimental study on a prismatic solar pond. It is internally painted in bla
ck with a surface
measurement of (1m2) and a lower measurement of (0.42m2) and 1m deep. It constitutes
four levels of gradual salinity separated by transparent glassy tablets /home glass/ of
(6mm) thickness. On its lower level, a black solid mass is placed (black volcanic stones of
equal dimensions; almost around 1cm). Upon studying the temperature and the stored
thermal amounts of via subsidiary time every day from 9 am until 5 pm, the average rate of
stored thermal amount each hour calculated according to the following equation:
(Q = m.Cp.ΔT) during six months (February until July 2016) was:
9962.445 KJ, 9516.28 KJ, 10783.471 KJ, 9765.836 KJ, 14010.393 KJ, 12164.320 KJ
respectively.
The study was carried out on trifoliate orange rootstock trees (Poncirus trifoliata L.)
at Ciano Research Station where the trees were sprayed with nutrients or gibberelic acid
GA3 or togethers, beside the control (without spraying). Different trea
tments of seed
storage were tested in order to study their effect on seed viability to increase it. The seeds
were stored for three months using four treatments: (a) seed storage in fruits at +4˚C, (b)
Storage in juice at +4˚C, (c) Storage at lab temperature, and (d) seed storage at fridge
temperature +4˚C. The results showed that all spraying treatments were positive at
postharvest, as compared with the control. However, treatment of seed storage inside the
fruit gave the highest significant germination rate for all spraying treatments. Treatments
of spraying with nutrients were the best. The viability of seeds considerably decreased for
all treatments of seed storage at fridge temperature +4˚C, whereas germination was zero for
seed stored in juice and seed stored at lab temperature.
This research was done by using a mathematical modeling for a heat storage tank by
the preparation a mathematical function using MATLAB software for charging and discharging
phase of the storage tank . it was applied partial storage strategy on a d
efault
building located in the city of Palmyra in the Syrian desert. peak cooling load (420 kW)
and storing (1420 kw-h) within a storage tank size of "30m3" So that the store of ice at
night and melting using outer fusion technology (External Melt) in thermal and electrical
peak hours in the next day .
The results showed the feasibility of a thermal modeling of the tank to cover the
air-conditioning load cooling load required ,the results also showed the shift of part of the
electrical daily load of the chiller about (576 Kw-h) with a clear reduction of mechanical
and electrical equipment with the provision of using electrical energy to a summer season
about (1376 kW-h/Season) and improving the daily electrical factor (DLF) achieves stability
of the electric system.
This paper presents the results can be generalized to large projects in the tropics
help in thermal and power consumption peak shift.
Thermal energy can be stored as a latent heat in building structures
by materials with low phase change temperature called phase
change materials (PCM).
In this paper, an analytical and mathematical study of the PCM
wallboards was done by simulat
e its thermal behavior, depending on
governing heat transfer equations which describe the phase change
process of the PCM wallboard.
The integration of various renewable energy sources as well as the liberalization of
electricity markets are established facts in modern electrical power systems. The increased
share of renewable sources within power systems intensifies the supply
variability and
intermittency. Therefore, energy storage is deemed as one of the solutions for stabilizing
the supply of electricity to maintain generation-demand balance and to guarantee
uninterrupted supply of energy to users. In the context of sustainable development and
energy resources depletion, the question of the growth of renewable energy electricity
production is highly linked to the ability to propose new and adapted energy storage
solutions. Recent advancements in hydrogen technologies and renewable energy
applications show promise for economical near to conversion to a hydrogen-based
economy. As the use of hydrogen for the electric utility and transportation sectors. This
paper briefly discusses provides a historical perspective for hydrogen production and the
role of hydrogen as an energy carrier, discusses hydrogen economy, the process of
electrolysis for hydrogen production (especially from solar and wind technologies).
A comprehensive techno/socio/economic study of long term hydrogen based
storage systems in electrical networks is addressed. the excess produced hydrogen during
high generation periods or low demand can be sold either directly to the grid owners or as
filled hydrogen bottles. The affordable use of Hydrogen-based technologies for long term
electricity storage is verified. The results indicate that ample resources exist to produce
Hydrogen from wind and solar power. However, hydrogen prices are highly dependent on
electricity prices.
This paper treats the issue of wind energy storage, mechanically, using the flywheel
device. We control the speed of the wind turbine and the flywheel by means of traditional
PID controllers. These controllers are designed depending on the system m
odel and its
parameters. Speed control is achieved by electromagnetic rotor flux orientation as called
vector control. Speed reference value of the wind turbine will be generated in order to track
the maximum power point. The flywheel reference speed is generated based on a second
order filter of power which is considered as a new contribution in this field of research.
Frequency converters are not modeled but we only consider the control strategy. The
results of modeling and simulation in Matlab satisfy the power smoothing issue and reflect
the importance of this study.
This research includes studying and creating a modern model to convert the
mechanical energy of sea waves into electrical power. This model uses wave’s mechanical
energy to pump water to dam rises above sea level, which in turn can run water turbin
e and
get electrical energy in the conditions of Syrian coast. The search also includes a computer
program written using Visual Basic.net, so that the program calculates the station
according to the data of the waves in the geographical area that are selected and show the
results in a clear value curves, after that we get useful proposals aims to build and develop
this model at the future.
