Murat Kacira

• PhD
• Professor at University of Arizona

Recognizing the growing interest in the application of organic photovoltaics (OPVs) with greenhouse crop production systems, in this study we used flexible, roll-to-roll printed, semi-transparent OPV arrays as a roof shade for a greenhouse hydroponic tomato production system during a spring and summer production season in the arid southwestern U.S....

A study related to the application of organic photovoltaic (OPV) modules in greenhouses is presented. It considers the impact of nonhomogeneous shading by semitransparent OPV modules, placed on the cover of a greenhouse tunnel housing a tomato crop, on energy partitioning and the spatial variability of radiation, air temperature and vapour pressure...

Monitoring equipment for plant-factory automation requires big capital investments. Low-cost open-source microcontroller platforms have been employed in agriculture to monitor and control different variables of importance for crop production. A low-cost plant-factory monitoring system for measuring air temperature, relative humidity, plant-leaf tem...

The use of flexible and semi-transparent organic photovoltaic (OPV) modules as shading elements in a greenhouse tunnel with a tomato crop is presented. Experiments were performed in two similar greenhouse tunnels, covered by diffuse polyethylene sheet, during two summer growing seasons. In 2018, one tunnel was shaded using OPV modules (covering 37%...

This study presents a detailed analysis of the outdoor behaviour of organic photovoltaic (OPV) panels on a polytunnel type greenhouse roof in a Mediterranean climate, looking at the effects of environmental variables and panel orientations on the electrical behaviour and degradation of the panels, thus providing crucial outdoor testing results of g...

This study examines the feasibility of using semi-transparent, flexible organic photovoltaic (OPV) modules as greenhouse shading material. By using such modules, it may be possible to utilise existing greenhouse-based agricultural areas for electricity production. Using OPV modules to shade greenhouses and reduce excess solar energy may result in r...

Raising poultry in livestock buildings requires housing that can provide acceptable living conditions in terms of climate and air quality. Accurately assessing the interior climate dynamics of a naturally ventilated poultry house needs advanced computer-based modelling tools. The present work proposes a three-dimensional modelling tool that uses co...

Air inside poultry houses must be removed on a regular basis to prevent excess of heat, particles and noxious gases that can imperil animals. To cope with this issue, natural ventilation could be an effective method when assisted by accurate predictions. This study investigates air discharges caused by natural ventilation of a poultry house by mean...

This paper summarizes the main developments achieved up to now on dynamical models of the greenhouse climate, regarding their structure, analysis, parameter estimation and model performance. The systems state-space approach is followed in order to describe main models’ structure features. The physical processes included in the dynamic equations of...

This study presents a simulation model incorporating a crop growth model for predicting plant produce yield and a solar radiation model for estimating electric energy production under various organic photovoltaic film (OPV) coverage ratios and angles at a laboratory-use greenhouse at Tucson, AZ, USA. The results showed that the model predicted lett...

Plant factories, essentially an enclosed warehouse with artificial lighting produces crops indoors in multi-layers under fully controlled environmental conditions. Existing commercial systems have been mostly constructed inside a warehouse building with multi-layer production shelves without considering detailed engineering design fundamentals with...

Air distribution system in plant factories with artificial lighting (PFALs) is responsible for the air exchange and replacement to create desired growing conditions for plants. Combined effects of multitiers, heat from supplemental lighting, improper air conditioning, and air distribution system design can lead to environmental nonuniformity in PFA...

Natural ventilation represents a strong tool for ameliorating climate and air quality in poultry houses if the benefits of weather conditions can be maximised. To that end, this investigation analyses the impact of natural ventilation on the dynamics of the internal climate of a poultry house focussing on the role played by the outside climatic par...

free access until December 13, 2016 http://authors.elsevier.com/a/1TxFg5Tbkjzmo6 Multisensory platforms for remote sensing measurements offer the possibility to monitor in real-time the crop health status without affecting the crop and environmental conditions. The concept of the speaking plant approach, and plant response based sensing in general...

Indoor plant factories are one of the alternative ways to meet the demands of food production for the increased urban dwellers. It enables growers to grow food crops consistently and locally with high quality. In an indoor plant factory, a forced convection based ventilation and circulation system is used to control the growing environment and main...

Semiarid climate regions have great potential for productivity due to large amounts of solar radiation throughout year. However, these regions also have disadvantages, such as excessive air temperature and limited water use. Optimizing the ventilation rate and evapotranspiration during fog cooling in combination with natural ventilation will provid...

The goals of this investigation were to evaluate a Bioregenerative Life Support System (BLSS) approach for a sustained human surface presence on the Moon (or Mars) for a four-person crew by the development and/or demonstration of polyculture crop production, system mass balances and flow of input/output resources, biomass recycling, energy generati...

A multi-wavelength based optical density sensor unit was designed, developed, and evaluated to monitor microalgae growth in real time. The system consisted of five main components including: (1) laser diode modules as light sources; (2) photodiodes as detectors; (3) driver circuit; (4) flow cell; and (5) sensor housing temperature controller. The s...

Using Computational Fluid Dynamics (CFD), we investigated the spread of gases inside and around of a poultry house. A 3D CFD model takes account of the natural ventilation combined with heat and water vapour produced by the animals. In order to validate a 3D CFD model a cycle of production for experimental purposes located West of France during the...

A 2D CFD model was developed to simulate interior climate of a poultry house. To validate the CFD model, an experiment was conducted in West of France during spring 2014. Two cases were evaluated: Case I and II at the early (19th day) and late (69th day) stage of production, respectively. For Case II, the CFD model evaluated three different densiti...

Improvements to the living conditions in semi-enclosed spaces such as broiler houses can be achieved by better control of the heat and mass transport that occur in climate and air quality. This study shows that computer-aided modelling, and in particular computational fluid dynamics (CFD), can provide to researchers the ability to integrate the pri...

An autonomous computer vision-guided plant sensing and monitoring system was designed and constructed to continuously monitor temporal, morphological, and spectral features of lettuce crop growing in a nutrient film technique (NFT) hydroponics system. The system consisted of five main components including (1) a stepper motor-driven camera positioni...

This study aims to use Computational Fluid Dynamic (CFD) software to explore the distributed climate inside greenhouses and especially in the leaf boundary layer, natural habitat of plant pests. Knowing more precisely the climatic conditions prevailing at this level is a prerequisite to the control of the climate at this level in order to fight aga...

Selective filtration of sunlight has been shown to affect the growth of plants. In this research a side-by-side comparison was done between two greenhouses, a conventional (control) greenhouse covered with double-layer acrylic panels and an experimental greenhouse covered with a glazing that creates a red-rich diffuse light environment while genera...

In 2010 Thales Alenia Space Italia (TAS-I) tailored and applied an existing plant growth model for application to the University of Arizona Controlled Environment Agriculture Center (UA-CEAC) Lunar Greenhouse Prototype (LGH). The activity was carried on in collaboration with UA-CEAC and Sadler Machine Co. (USA) in the framework of the NASA Ralph St...

Intensive production of broilers is seen as a promising way to efficiently operate livestock buildings. However, there are great concerns about the required optimal settings that accomplish the best living conditions for the animal. These living conditions strongly depend on the broiler house climate dynamics. The assessment of climate, incorporati...

The operation of animal housing requires a comprehensive analysis of the interaction between the animal and its surroundings. Apart from good nutrition and management, comfortable living conditions, in particular, climate can also enhance animal productivity. The climate conditions become one of the main problems to solve once there are prevalent h...

Natural resources such as water, land, and energy are increasingly diminished as the human population increases past seven billion. Approximately fifty percent of the world's population subsides on less than $ 2.50 per a day and 1.6 billion people live without electricity. Thus, it is vital to increase the productivity and efficiency of resource us...

Natural ventilation (NV) is the most frequently used method worldwide to maintain appropriate greenhouse conditions for plant growth. However, when adequate ventilation rates to evacuate the excessive heat are not possible, other alternatives such as evaporative cooling systems may enhance the cooling capabilities of the NV systems. Although high-p...

A machine vision guided plant sensing and monitoring system was designed and constructed to autonomously monitor and extract color features (Red-Green- Blue, Hue-Saturation-Luminance, and Color Brightness), textural features (Contrast, Energy, Entropy, and Homogeneity), morphological feature (Top Projected Canopy Area), plant indices (from NIR band...

Intensive production of broilers is seen as a promising way to efficiently operate livestock buildings. However, there are great concerns about the required optimal settings that accomplish the best living conditions for the animal. These living conditions strongly depend on the broiler house climate dynamics. The assessment of climate, incorporati...

High pressure fogging systems and control strategies in naturally ventilated (NV) greenhouses has been investigated as an alternative cooling mechanism to mechanical ventilation systems with aims of saving energy and water and potentially helping to improve climate uniformity in the greenhouse. Studies on analyzing the climate uniformity under NV w...

This study aims to use Computational Fluid Dynamic (CFD) software to explore the distributed climate inside greenhouses and especially in the leaf boundary layer, natural habitat of plant pests. Knowing more precisely the climatic conditions prevailing at this level is a prerequisite to the control of the climate at this level in order to fight aga...

Greenhouse workers constitute a particularly interesting group, as their exposure to pesticides is not only greater in comparison to outdoor agricultural workers, but also occurs continuously throughout the whole year. In the present paper the dermal and inhalation exposure of greenhouse workers after pesticides application was evaluated based on e...

Controlled environments have long played an important role in the field of agriculture because they enable growers to more precisely regulate not only the quantity of a crop but the quality as well. Currently, most controlled environments rely on mechanical systems to regulate temperature and relative humidity within the controlled space, but these...

A very significant event in the world history of Agriculture is the domestication of plants by mankind. Instead of depending on wild growth, it was realized that the planting of seeds or cuttings allowed the propagation of the type of plants desired. Another important breakthrough resulted from the need to protect the domesticated plants from abiot...

A control strategy for greenhouse cooling with natural ventilation and variable high-pressure fog was evaluated via computer simulation and verified experimentally. Two set points were used, one based on air specific enthalpy (56 kJ kg-1) for determining the vent openings, and the other based on vapor pressure deficit (VPD) of the air (1.0 kPa) for...

Computational fluid dynamics (CFD) is a proven simulation tool which caters to almost any field of study. The CFD technique is utilized to simulate, analyze, and optimize various engineering designs. In this review, the discussion is focused on the application of CFD in the external atmospheric processes as well as modeling in land and water manage...

Models are required to accurately predict mass and energy balances in a bioregenerative life support system. A modified energy cascade model was used to predict outputs of a multi-crop (tomatoes, potatoes, lettuce and strawberries) Lunar greenhouse prototype. The model performance was evaluated against measured data obtained from several system clo...

This study was conducted to determine the drag coefficient and the relationship between permeability (K) and momentum loss coefficients (C f) of a tomato canopy for various leaf area densities. The experiments were conducted in a large-scale wind tunnel system with a tomato canopy. The static pressures and air velocity measurements were performed a...

In semi-arid and arid environments, naturally vented greenhouses are either not in use or generate low-quality produce during hot period due to inability of current climate control systems to maintain acceptable temperature and humidity at a reasonable cost. A climate control strategy was developed and implemented based on air enthalpy for vent con...

Bio-regenerative Life Support Systems (BLSS) uses biological processes to support an astronaut crew, and includes atmosphere revitalization, water recycling, food production, and organic waste recycling. The University of Arizona Controlled Environment Agriculture Center (UA-CEAC), Systems and Industrial Engineering Department, Sadler Machine Co. (...

Cooling must be supplied for greenhouses located in semiarid climates most of the year to provide desired climate conditions for year-round crop production. High-pressure fogging systems have shown promising results for cooling, however the lack of effective control strategies, especially under passive ventilation, have limited their use. In this s...

Passive ventilation in greenhouse production systems is predominant worldwide, limiting its usability and profitability to specific regions or for short production cycles. Evaporative fogging systems have increasingly been implemented in Arid and Semi-Arid regions to extend the production cycle during the warmest season, and also to achieve near-op...

The South Pole Food Growth Chamber (SPFGC) is an automated hydroponic climate controlled chamber located inside the Amundsen-Scott South Pole station, which produces fresh vegetables and herbs, as well as a psychologically pleasurable environment for station personnel. The objective of this study was to document the SPFGC automated control practice...

Future habitation of space, including lunar outposts will require special systems capable of performing important tasks such as revitalizing atmosphere (generate oxygen and fix carbon dioxide), purifying water (e.g., via plant transpiration), and growing human food. Bioregenerative Life Support Systems (BLSS) represent a solution to the problem of...

The present study examines how climatic conditions and pond design affect the growth performance of microalgae. From January to April of 2011, outdoor batch cultures of Nannochloropsis salina were grown in three replicate 780 L conventional raceways, as well as in an experimental 7500 L algae raceway integrated design (ARID) pond. The ARID culture...

Effects of end-of-day far-red (EOD-FR) light on hypocotyl elongation of a commercial cucurbit rootstock were investigated using movable and stationary light fixtures, since adequate hypocotyl length is required in vegetable grafting. Seedlings of an interspecific squash ‘Tetsukabuto’ (Cucurbita maxima x Cucurbita moschata) were grown in greenhouse...

In addition to ventilation, daily cooling must be provided for greenhouses located in semiarid climates to maintain the desired climate conditions for year-round crop production. High-pressure fogging systems have been successfully developed for greenhouse cooling. However the lack of control strategies, in combination with ventilation systems, esp...

A climate control system for a small greenhouse equipped with a variable-pressure fogging system and variable-speed extracting fans was developed and validated. The controllers were designed using the robust control method quantitative feedback theory (QFT) that guarantees adequate performance of the controlled system despite large modelling uncert...

Bio-regenerative Life Support Systems (BLSS) is the application of biological based processes to support an astronaut crew in space, including atmosphere revitalization, water recycling, food production, and organic waste recycling. Future long term lunar/Mars surface missions will require a high degree of redundancy with dissimilar systems for cre...

Visual sensor networks (VSNs) have emerged as a new paradigm by giving sensors the capability to perceive and analyze their surroundings. Robust and fault-tolerant operations are crucial for non-contact plant monitoring systems in a greenhouse environment equipped with a VSN. Achieving such capabilities requires new methods to monitor system status...

A machine vision guided real time plant health/growth and quality monitoring system was designed and developed for use in controlled environment plant production systems. The developed system consisted of two main components including a robotic positioning system to place a color CCD camera on designated plants or on the canopy, and an image proces...

In the last decade there has been an exponential increase in the number of research works using computational fluid dynamic simulations to study natural ventilation processes in greenhouses. The main reasons for this are that Computational Fluid Dynamics (CFD) simulations can provide a vast amount of information in a cost effective way in a reasona...

Even though several models to predict evapotranspiration (ET) of greenhouse crops have been developed, previous studies have evaluated them under fixed greenhouse conditions. It is still not clear which model is more appropriate, accurate, and best suited for applications such as inclusion in greenhouse cooling strategies for different crops, clima...

This work presents the development and validation of robust controllers for greenhouses equipped with a climate control system that consists of variable-pressure fogging and variable-speed extracting fans. The controllers were designed using the robust control method "Quantitative Feedback Theory" that guarantees adequate performance of the control...

Conventional greenhouse environmental conditions are determined by observation. However, destructive or invasive contact measurements are not practical for real-time monitoring and control applications. At the canopy scale, machine vision has the potential to identify emerging stresses and guide sampling for identification of the stressor. A machin...

With concurrent interests on Bio-regenerative Life Support Systems (BLSS), Italian and USA industrial and academic institutions, including Thales Alenia Space Italia (TAS-I), the University of Arizona (UA) and the Sadler Machine Company have teamed in a collaboration effort. The collaboration has been providing personnel exchanges, sharing accumula...

Previous studies on high pressure fogging have shown their capability for maintaining temperature and humidity in acceptable ranges most of the year in greenhouses located in semiarid regions. The heat load, and therefore cooling demand, inside the greenhouse vary during the day and throughout the seasons. Thus, it may be advantageous to use a vari...

Visual Sensor Networks (VSN) has emerged as a new paradigm by giving a sensor the capability to perceive and analyze its surrounding. Creating an environment of “no doubt” is essential for a contact free plant monitoring system in a greenhouse environment equipped with VSN. Methods to monitor a system’s health, and respond to hardware anomalies aut...

Greenhouse crop production systems have been established throughout the world, including arid and semi-arid regions, to fulfill a market demand of locally grown produce consistently through the year. In these particular regions while they have the advantage of sunshine year-round, production during the summer is a challenge due to elevated air temp...

To establish successful CEA operations, education, training, and experience for the system operators are required. Decision support from off-site consultants or other support groups can be beneficial to help the operation, but to provide an effective response, they require environmental information and plant status, as well as, easy access to suffi...

The Prototype BLSS Lunar Greenhouse currently in operation at the University of Arizona - Controlled Environment Agriculture Center in Tucson, Arizona is an Advanced Life Support technology demonstration for supporting a sustained human presence at the future lunar science outpost. The focus of the investigation is to demonstrate water recycling, a...

The present work deals with determining barriers for thermal energy and electricity generation from agricultural biomass in Turkey. Strategy development and determination of barriers were investigated in accordance with the work program requirements for the project entitled "Exploitation of Agricultural Waste in Turkey" under the European Life Thir...

An assessment of the applicability of EU biomass technologies in Turkey is presented. SWOT analysis was applied for the implementation of EU biomass technology in Turkey. Market overview, EU biomass technologies implementation in Turkey, market competition and comparison with competing fuels, manufacturers-distribution channels-sales networks, appl...

This study was conducted to determine the effects of vent configuration and external wind speed on three-dimensional distribution of air temperature in a naturally ventilated multi-span greenhouse using wind tunnel experiments. The experiments were conducted with the scale models in a wind tunnel with four different vent configurations and at four...

The objective of this study is to determine the agricultural biomass potential in terms of types, quantities and regional distribution in Turkey. The calorific values of a selection of agricultural residues were determined by stoichiometric analyses. It was found that the total calorific value of the field crop residues was around 228 PJ/year for t...

The main objective of the present study is to determine the regional distribution of agricultural residue potential in Turkey. The available information on agricultural waste in Turkey was identified and reviewed. Although the main sources of information were gathered from the Ministry of Environment, the Ministry of Agriculture, State Institute of...

A study was conducted to determine the effects of different drip irrigation regimes on yield and yield components of cucumber (Cucumbis sativus L.) and to determine a threshold value for crop water stress index (CWSI) based on irrigation programming. Four different irrigation treatments as 50 (T-50), 75 (T-75), 100 (T-100) and 125% (T-125) of irrig...

The effect of environmental variability is one of the major concerns in experimental design for both research in plant systems and greenhouse plant production. Microclimates surrounding plants are not usually uniform. Therefore, many samples and sensors are required to obtain a true representation of the plant population. A plant monitoring system...

The effects of greenhouse vent configurations, plant existence, and external wind speeds on ventilation rates and airflow patterns in a greenhouse and plant canopy zone under wind-induced ventilation were investigated. The optimization of traditional vent configuration for a two-span glasshouse for better air renewal, especially in the plant canopy...

In this paper, the effects of wind speed, side ventilators and span numbers on gothic type multi-span greenhouse natural ventilation were studied by numerical simulation using the Computational Fluid Dynamics (CFD) approach. The realizable k-ε model was used for the turbulence model in the simulations. The results showed that the maximum greenhouse...

The performance of a photovoltaic (PV) panel is affected by its orientation and its tilt angle with the horizontal plane. This is because both of these parameters change the amount of solar energy received by the surface of the PV panel. A mathematical model was used to estimate the total solar radiation on the tilted PV surface, and to determine o...

This study was conducted to investigate the effects of drip irrigation on yield and yield components of watermelon [Citrullus lanatus (Thunb.) Crimson Tide F1] under semiarid conditions in the Southeastern Anatolian Project Region, Harran Plain, Şanlıurfa, Turkey, during 2002 and 2003. Using a 4-day irrigation period, 4 different irrigation regimes...

A methodology was established for early, non-contact, and quantitative detection of plant water stress with machine vision extracted plant features. Top-projected canopy area (TPCA) of the plants was extracted from plant images using image-processing techniques. Water stress induced plant movement was decoupled from plant diurnal movement and plant...

Early, non-contact, non-destructive, and quantitative detection of plant water stress with the application of infrared thermometry using a crop water stress index (CWSI) was established. A CWSI model for plants grown under controlled environments was developed using thermodynamic principles and energy balance of the plant. CWSI threshold values wer...

An automated system was designed and built to continuously monitor plant health and growth in a controlled environment using a distributed system approach for operational control and data collection. The computer-controlled system consisted of a motorized turntable to present the plants to the stationary sensors and reduce microclimate variability...

A computational fluid dynamics program, FLUENT V4, was used to determine ventilation rates and air flow patterns of a multi-span sawtooth greenhouse for various roof and side vent openings and outside wind speeds. The combined effects of roof and windward side openings resulted in ventilation rates up to four times standard fan recommendations. The...

A computational fluid dynamics (CFD) program, Fluent V4, was used to predict natural ventilation rates and airflow patterns of a multi-span sawtooth greenhouse for various roof and side vent openings and outside wind speeds. Predicted rates were found to be both well above and well below a standard volumetric air exchange rate of l.0 A.C. min-1. Th...