Abstract: Hydroponic greenhouses systems (production of the artificial substrate without soil) are becoming popular in the world. Mostly the system is used to grow vegetables and berries. Different countries are taking action to participate in the development of hydroponic technology and solutions such as EU members, Turkey, Australia, New Zealand, Israel, Scandinavian countries, etc. Many vegetables and berries are grown by hydroponics in Europe. As a result of our research, we have obtained material containing manganese and nitrogen. It became possible to produce this fertilizer by means of one-stage thermal processing, using industrial waste containing manganese (ores and sludges) and mineral substance (ammonium nitrate) that exist in Georgia. The received material is usable as a micro-fertilizer with economic efficiency. It became possible to turn practically water-insoluble manganese dioxide substance into the soluble condition from industrial waste in an indirect way. The ability to use the material as a fertilizer is predetermined by its chemical and phase composition, as the amount of the active component of the material in relation to manganese is 30%. At the same time, the active component elements presented non-ballast sustained action compounds. The studies implemented in Poland and in Georgia by us have shown that the manganese-containing micro-fertilizer- Mn(NO3)2 can provide the plant with nitrate nitrogen, which is a form that can be used for plants, providing the economy and simplicity of the application of fertilizers. Given the fact that the application of the manganese-containing micro-fertilizers significantly increases the productivity and improves the quality of the big number of agricultural products, it is necessary to mention that it is recommended to introduce the manganese containing fertilizers into the following cultures: sugar beet, corn, potato, vegetables, vine grape, fruit, berries, and other cultures. Also, as a result of the study, it was established that the material obtained is the predominant fertilizer for vegetable cultures in the soil. Based on the positive results of the research, we consider it expedient to conduct research in hydroponic systems, which will enable us to provide plants the required amount of manganese; we also introduce nitrogen in solution and regulate the solution of pH, which is one of the main problems in hydroponic production. The findings of our research will be used in hydroponic greenhouse farms to increase the fertility of vegetable crops and, consequently, to get bountiful and high-quality harvests, which will promote the development of hydroponic greenhouses in Georgia as well as abroad.
Abstract: Over 60% highly transparent quasi-solid-state dye-sensitized solar cells (DSSCs) with dimension of 50x50 cm2 were fabricated via inkjet printing process using nanocomposite inks as raw materials and tested under outdoor illumination conditions. The cells were electrically characterized, and their possible application to the shell of greenhouses was also examined. The panel design was in Z-interconnection, where the working electrode was inkjet printed on one conductive glass and the counter electrode on a second glass in a sandwich configuration. Silver current collective fingers were printed on the glasses to make the internal electrical connections. In that case, the adjacent cells were connected in series via silver fingers and finally insulated using a UV curing resin to protect them from the corrosive (I-/I3-) redox couple of the electrolyte.
Abstract: Dry reforming of methane that converts two greenhouses gases (CH4 and CO2) to synthesis gas (a mixture of H2 and CO) was studied in a commercial bench scale microwave (MW) plasma reactor system at atmospheric pressure. The CO2, CH4 and N2 conversions; H2, CO selectivities and yields, and syngas ratio (H2/CO) were investigated in a wide range of total feed flow rate (0.45 – 2.1 L/min), MW power (700 – 1200 watt) and CO2/CH4 molar ratio (2 – 5). At the feed flow rates of CH4, CO2 and N2 of 0.2, 0.4 and 1.5 L/min respectively, and the MWs input power of 700 W, the highest conversions of CH4 and CO2, selectivity and yield of H2, CO and H2/CO ratio of 79.35%, 44.82%, 50.12, 58.42, 39.77%, 32.89%, and 0.86, respectively, were achieved. The results of this work show that the product ratio increases slightly with the increasing total feed flow rate, but it decreases significantly with the increasing MW power and feeds CO2/CH4 ratio.
Abstract: The integration of agricultural production systems into urban areas is a challenge for the coming decades. Because of increasing greenhouse gas emission and rising resource consumption as well as costs in animal husbandry, the dietary habits of people in the 21st century have to focus on herbal foods. Intensive plant cultivation systems in large cities and megacities require a smart coupling of information, material and energy flow with the urban infrastructure in terms of Horticulture 4.0. In recent years, many puzzle pieces have been developed for these closed processes at the Humboldt University. To compile these for an urban plant production, it has to be optimized and networked with urban infrastructure systems. In the field of heat energy production, it was shown that with closed greenhouse technology and patented heat exchange and storage technology energy can be provided for heating and domestic hot water supply in the city. Closed water circuits can be drastically reducing the water requirements of plant production in urban areas. Ion sensitive sensors and new disinfection methods can help keep circulating nutrient solutions in the system for a longer time in urban plant production greenhouses.
Abstract: A traditional greenhouse is a metal frame agricultural building used for cultivation plants in a controlled environment isolated from external climatic changes. Using greenhouses in agriculture is an efficient way to reduce the water consumption, where agriculture field is considered the biggest water consumer world widely. Controlling greenhouse environment yields better productivity of plants but demands an increase of electric power. Although various control approaches have been used towards greenhouse automation, most of them are applied to traditional greenhouses with ventilation fans and/or evaporation cooling system. Such approaches are still demanding high energy and water consumption. The aim of this research is to develop a fuzzy control system that minimizes water and energy consumption by utilizing outside weather conditions and underground heat exchanger to maintain the optimum climate of the greenhouse. The proposed control system is implemented on an experimental model of thermally isolated greenhouse structure with dimensions of 6x5x2.8 meters. It uses fans for extracting heat from the ground heat exchanger system, motors for automatic open/close of the greenhouse windows and LED as lighting system. The controller is integrated also with environmental condition sensors. It was found that using the air-to-air horizontal ground heat exchanger with 90 mm diameter and 2 mm thickness placed 2.5 m below the ground surface results in decreasing the greenhouse temperature of 3.28 ˚C which saves around 3 kW of consumed energy. It also eliminated the water consumption needed in evaporation cooling systems which are traditionally used for cooling the greenhouse environment.
Abstract: This paper presents an image analysis algorithm to detect and count yellow tomato flowers in a greenhouse with uneven illumination conditions, complex growth conditions and different flower sizes. The algorithm is designed to be employed on a drone that flies in greenhouses to accomplish several tasks such as pollination and yield estimation. Detecting the flowers can provide useful information for the farmer, such as the number of flowers in a row, and the number of flowers that were pollinated since the last visit to the row. The developed algorithm is designed to handle the real world difficulties in a greenhouse which include varying lighting conditions, shadowing, and occlusion, while considering the computational limitations of the simple processor in the drone. The algorithm identifies flowers using an adaptive global threshold, segmentation over the HSV color space, and morphological cues. The adaptive threshold divides the images into darker and lighter images. Then, segmentation on the hue, saturation and volume is performed accordingly, and classification is done according to size and location of the flowers. 1069 images of greenhouse tomato flowers were acquired in a commercial greenhouse in Israel, using two different RGB Cameras – an LG G4 smartphone and a Canon PowerShot A590. The images were acquired from multiple angles and distances and were sampled manually at various periods along the day to obtain varying lighting conditions. Ground truth was created by manually tagging approximately 25,000 individual flowers in the images. Sensitivity analyses on the acquisition angle of the images, periods throughout the day, different cameras and thresholding types were performed. Precision, recall and their derived F1 score were calculated. Results indicate better performance for the view angle facing the flowers than any other angle. Acquiring images in the afternoon resulted with the best precision and recall results. Applying a global adaptive threshold improved the median F1 score by 3%. Results showed no difference between the two cameras used. Using hue values of 0.12-0.18 in the segmentation process provided the best results in precision and recall, and the best F1 score. The precision and recall average for all the images when using these values was 74% and 75% respectively with an F1 score of 0.73. Further analysis showed a 5% increase in precision and recall when analyzing images acquired in the afternoon and from the front viewpoint.
Abstract: Greenhouses offer us suitable conditions which can
be controlled easily for the growth of the plant and they are made by
using a covering material that allows the sun light entering into the
system. Covering material can be glass, fiber glass, plastic or another
transparent element. This study investigates the solar energy usability
rates and solar energy benefitting rates of a semi-spherical (modified
arch) type greenhouse system according to different orientations and
positions which exists under climatic conditions of Bayburt. In the
concept of this study it is tried to determine the best direction and
best sizes of a semi-spherical greenhouse to get best solar benefit
from the sun. To achieve this aim a modeling study is made by using
MATLAB. However, this modeling study is run for some determined
shapes and greenhouses it can be used for different shaped
greenhouses or buildings. The basic parameters are determined as
greenhouse azimuth angle, the rate of size of long edge to short and
seasonal solar energy gaining of greenhouse. The optimum azimuth
angles of 400, 300, 250, 200, 150, 100, 50 m2 modified arch
greenhouse are 90o, 90o, 35o, 35o, 34o, 33o and 22o while their
optimum k values (ratio of length to width) are 10, 10, 10, 10, 6, 4
and 4 respectively. Positioning the buildings in order to get more
solar heat energy in winter and less in summer brings out energy and
money savings and increases the comfort.
Abstract: Currently, biological control programs in greenhouse
crops involve the use, at the same time, several natural enemies
during the crop cycle. Also, large number of plant species grown in
greenhouses, among them, the used cultivars are also wide. However,
the cultivar effects on entomophagous species efficacy (predators and
parasitoids) have been scarcely studied. A new method had been
developed, using the factitious prey or host Ephestia kuehniella. It
allow us to evaluate, under greenhouse or controlled conditions
(semi-field), the cultivar effects on the entomophagous species
effectiveness. The work was carried out in greenhouse tomato crop. It
has been found the biological and ecological activities of predatory
species (Nesidiocoris tenuis) and egg-parasitoid (Trichogramma
achaeae) can be well represented with the use of the factitious prey
or host; being better in the former than the latter. The data found in
the trial are shown and discussed. The developed method could be
applied to evaluate new plant materials before making available to
farmers as commercial varieties, at low costs and easy use.
Abstract: This study aimed at designing and developing a
mechanical force gauge for the square watermelon mold for the first
time. It also tried to introduce the square watermelon characteristics
and its production limitations. The mechanical force gauge
performance and the product itself were also described. There are
three main designable gauge models: a. hydraulic gauge, b. strain
gauge, and c. mechanical gauge. The advantage of the hydraulic
model is that it instantly displays the pressure and thus the force
exerted by the melon. However, considering the inability to measure
forces at all directions, complicated development, high cost, possible
hydraulic fluid leak into the fruit chamber and the possible influence
of increased ambient temperature on the fluid pressure, the
development of this gauge was overruled. The second choice was to
calculate pressure using the direct force a strain gauge. The main
advantage of these strain gauges over spring types is their high
precision in measurements; but with regard to the lack of conformity
of strain gauge working range with water melon growth, calculations
were faced with problems. Finally the mechanical pressure gauge has
advantages, including the ability to measured forces and pressures on
the mold surface during melon growth; the ability to display the peak
forces; the ability to produce melon growth graph thanks to its
continuous force measurements; the conformity of its manufacturing
materials with the required physical conditions of melon growth; high
air conditioning capability; the ability to permit sunlight reaches the
melon rind (no yellowish skin and quality loss); fast and
straightforward calibration; no damages to the product during
assembling and disassembling; visual check capability of the product
within the mold; applicable to all growth environments (field,
greenhouses, etc.); simple process; low costs and so forth.
Abstract: Any use of energy in industrial productive activities is combined with various environment impacts. Withintransportation,
this fact was not only found among land transport, railways and maritime transport, but also in the air transport industry. An effective climate protection requires strategies and measures for reducing all
greenhouses gas emissions, in particular carbon dioxide, and must
take into account the economic, ecologic and social aspects. It seem simperative now to develop and manufacture environmentally
friendly products and systems, to reduce consumption and use less
resource, and to save energy and power. Today-sproducts could
better serve these requirements taking into account the integration of
a power management system into the electrical power system.This
paper gives an overview of an approach ofpower management with
load prioritization in modernaircraft. Load dimensioning and load
management strategies on current civil aircraft will be presented and
used as a basis for the proposed approach.
Abstract: Electric vehicle (EV) is one of the effective solutions to
control emission of greenhouses gases in the world. It is of interest
for future transportation due to its sustainability and efficiency by
automotive manufacturers. Various electrical motors have been used
for propulsion system of electric vehicles in last decades. In this
paper brushed DC motor, Induction motor (IM), switched reluctance
motor (SRM) and brushless DC motor (BLDC) are simulated and
compared. BLDC motor is recommended for high performance
electric vehicles. PWM switching technique is implemented for speed
control of BLDC motor. Behavior of different modes of PWM speed
controller of BLDC motor are simulated in MATLAB/SIMULINK.
BLDC motor characteristics are compared and discussed for various
PWM switching modes under normal and inverter fault conditions.
Comparisons and discussions are verified through simulation results.
Abstract: Photoselective plastic films with thermic properties
are now available so that greenhouses clad with such plastics exhibit
a higher degree of “Greenhouse Effect” with a consequent increase in
night time temperature. In this study, we investigate the potential
benefits of a range of thermic plastic films used as greenhouse cover
materials on the vegetative and reproductive growth and development
of Iceberg lettuce (Lactuca sativa L). Transplants were grown under
thermic films and destructively harvested 4, 5, and 6 weeks after
transplanting. Thermic films can increase night temperatures up to 2
⁰C reducing the wide fluctuation in greenhouse temperature during
winter compared to the standard commercial film and consequently
increased the yield (leaf number, fresh weight, and dry weight) of
lettuce plants. Lettuce plants grown under Clear film respond to cold
stress by the accumulation of secondary products (phenolics, and
flavonoids).
Abstract: Many agricultural and especially greenhouse
applications like plant inspection, data gathering, spraying and
selective harvesting could be performed by robots. In this paper
multiple nonholonomic robots are used in order to create a desired
formation scheme for screening solar energy in a greenhouse through
data gathering. The formation consists from a leader and a team
member equipped with appropriate sensors. Each robot is dedicated
to its mission in the greenhouse that is predefined by the
requirements of the application. The feasibility of the proposed
application includes experimental results with three unmanned
ground vehicles (UGV).