MAIN ASPECTS OF DRIP IRRIGATION DESIGN, CONSTRUCTION AND SCOPE
OF APPLICATION
V. Florov
HIGH ENERGY RADIATION RESISTANCE OF ADVANCED
ENGINEERING PLASTIC PRODUCTS
M. Natov, N. Cholakova*
ALTERNATIVE TECHNOLOGIES FOR DESTRUCTION OF CHEMICAL WEAPONS
M. Haralampiev
ON SOME MILESTONES IN THE SCIENCE AND TECHNOLOGY OF RUBBER
N. Dishovsky
A REVIEW ON THE VISCOSITY ADDITIVES IN MOTOR OILS
S. Stefanov, K. Stanulov, S. Vassileva
MAIN ASPECTS OF DRIP IRRIGATION DESIGN,
CONSTRUCTION AND SCOPE OF APPLICATION
V. Florov
|
Institute of
Land Reclamation and Agricultural Mechanization, 136, Tzar Boris III,
1618 Sofia
|
|
Many different systems for drip irrigation
are used in the modern agriculture. Their main advantages are that they permit
the economical usage of water (up to 50% reduction in the quantity of water
used), the automation of the irrigation processes and the ability to make
local water irrigation in steep terrain. Two systems are widely used in Bulgaria.
They are made of high density polyethylene, low density polyethylene and polypropilene.
The 'Agrodrip' system finds usage in the irrigation of vegetables and flowers
(both in greenhouses and in the open fields). The system combines an inner
corrugate pipe with an outer smooth pipe which are perforated at certain points.
A system, which combines smooth polyethylene pipe and 'labyrinth' type KP-4.6
drippers, is used for the drip irrigation of orchards and vineyards. The technical
characteristics of these systems manufactured by the Institute of Land Reclamation
and Agricultural Mechanization, the possibilities of their usage in the irrigation
of various crops, the main principles for the choice of such installations
and the economic effectiveness of such systems are viewed in the following
development.
Keywords: agriculture, drip irrigation, equipment, polymers, pipes,
drippers.
HIGH ENERGY RADIATION
RESISTANCE OF ADVANCED ENGINEERING PLASTIC PRODUCTS
M. Natov, N. Cholakova*
|
University of
Chemical Technology and Metallurgy,
8 Kl. Ohridski, 1756 Sofia, Bulgaria
E-mail: natov@uctm.edu
"Oblicos-96" Ltd, Sofia, Bulgaria
E-mail: oblicos@mbox.cit.bg
|
|
The highest achievement of the polymer chemistry
are the advanced engineering plastic products.
Their physico-mechanical, thermal and electrical properties and their chemical
resistance in different surroundings together with resistance against high-energy
radiation make them exclusively important for the development of many different
industrial branches.
The advanced engineering plastic products of Quadrant Engineering Plastic
Products-Belgium such as Ketron PEEK, Torlon, Techtron, Celazole, Cestidur,
Borolene have excellent resistance against high- energy radiation. They find
their application in nuclear industry- in cyclotrons, valves and other machined
parts in nuclear power stations; in textile industry - in spinning process
where X-rays for contolling some parameters of the raw material and produced
fibres are used; in medical industry- in UV-sterilizators, etc.; in chemical
industry - for process controlling; in electronic industry - for different
parts and also in many other industrial branches.
The presence of the above products on Bulgarian market makes possible their
introduction in the equivalent branches in our industry.
The knowledge and information about EPP of our technically competent persons
such as engineers and technicians, mechanics and constructors will result
in modernization and eco-protection in processes and apparats in all fields
where problems are available.
Keywords: high-energy radiation, engineering plastic products, X-rays
ALTERNATIVE TECHNOLOGIES FOR DESTRUCTION
OF CHEMICAL WEAPONS
M. Haralampiev
|
Organization
for Prohibition and Destruction of Chemical Weapons, Kingdom of Netherlands
E-mail: haro@wanadoo.nl
|
|
Alternative destruction technologies for
the chemical weapons have long been promoted by many groups of people in the
USA though the USA army has decided to use incineration as their basic technology
to destroy the huge chemical weapons stockpiles across the States. Actually
there are a few sites in the USA where there has already been successfully
tested with different alternatives and several new plants are being built
based on alternative technologies. The agent release (happened in May 2000)
in TOCDF, Tooele, Utah caused disturbances among the citizens living nearby.
A hot debate emerged also around the other sites in the USA where the same
incineration technology of CW destruction will be used (e.g Anniston, Alabama).
To seek an alternative technology rather than incineration has long been preferred
by many groups. Therefore it provided a good case for the opposition to incineration.
The TOCDF has been shut down for a few months since its agent release.
The aim of this paper is to compare the alternative technologies with the
incineration (which is also called baseline technology). It will cover the
following: a) the principles of these alternatives; b) the possible applications;
c) advantages and disadvantages.
It will be worthwhile to say, though, this paper is not comprehensive. The
major sources of this paper are open publications, Internet access.
Keywords: chemical weapons, destruction, neutralization, alternative
technologies.
ON SOME MILESTONES IN THE SCIENCE AND
TECHNOLOGY OF RUBBER
N. Dishovsky
|
University of
Chemical Technology and Metallurgy,
8 Kl. Ohridski, 1756 Sofia, Bulgaria
E-mail dishov@uctm.edu
|
|
The most important milestones in the development
of the rubber science and technology during the last 270 years have been considered
and discussed.
Keywords: rubber, vulcanization, network formation, reversible rubber
elasticity, theory of branching processes
A REVIEW ON THE VISCOSITY ADDITIVES IN
MOTOR OILS
S. Stefanov, K. Stanulov, S. Vassileva
|
University of
Chemical Technology and Metallurgy,
8 Kl. Ohridski, 1756 Sofia, Bulgaria
E-mail: batstefcho@yahoo.com
|
|
This paper reviews the types, chemistry and
mechanisms of different viscosity additives used to improve the viscosity-temperature
properties (VI - viscosity index) in different commercial oils.
Keywords: Friction modifier, viscosity index, additive, lubricant.
