Narrow Results

The residual fraction of anthropogenic CO₂ emissions which has not been captured by carbon sinks and remains in the atmosphere, is estimated by two independent experimental methods which support each other: the ¹³C/¹²C ratio and the temperature-independent fraction of d(CO₂)/dt on a yearly scale after subtraction of annual fluctuations the amplitude ratio of which reaches a factor as large as 7. The anthropogenic fraction is then used to evaluate the additional warming by analysis of its spectral contribution to the outgoing long-wavelength radiation (OLR) measured by infrared spectrometers embarked in satellites looking down. The anthropogenic CO₂ additional warming extrapolated in 2100 is found lower than 0.1°C in the absence of feedbacks. The global temperature data are fitted with an oscillation of period 60 years added to a linear contribution. The data which support the 60-year cycle are summarized, in particular sea surface temperatures and sea level rise measured either by tide gauge or by satellite altimetry. The tiny anthropogenic warming appears consistent with the absence of any detectable change of slope of the 130-year-long linear contribution to the temperature data before and after the onset of large CO₂ emissions.

Forecasting emerging technologies as well the rate of diffusion of resultant products are complex in the context of management of technology usually because of a lack of relevant data. Techniques such as bibliometric analysis and the Bass diffusion model are utilized in this paper to assess the growth rate and market penetration of computational fluid dynamics (CFD) as a technology. The penetration and growth rate of user acceptance of two CFD codes (not identified) are simulated. Furthermore, a technology forecasting model of research and innovation in the field of application of CFD in the assessment of greenhouses is presented. Some CFD results of simulations for internal and external flow in an eight-span greenhouse are presented as an illustration of the power of CFD as technology.

Microclimate modelling in a greenhouse is complicated due to the model’s irregularity and uncertainty of variable parameters. Evaluating the greenhouse’s changing climate is challenging since the conditions are always changing. As a result, it is necessary to determine the best way to manage the microclimate for the healthy development of growing plants. In order to maximise the growth of blooming plants, a modified leader optimisation algorithm (MLA) is created in this study to control the inside environment of a greenhouse. The implementation is done using greenhouses with a double-span structure located in Punjab and Mohali in India. The recommended approach analyses a number of characteristics, including carbon dioxide (CO₂) concentration, temperature, and humidity, to keep track of the greenhouse’s environment. The humidity, temperature and CO₂ content of flowering plants are studied using the proposed method implemented using MATLAB tool. The evaluated parameters are compared to conventional techniques like Battle Royale Optimisation (BRO), Particle Swarm Optimisation Algorithm (PSO), and BAT algorithm (BAT). Cost and energy consumption are also calculated for both proposed and existing models. Additionally, for the microclimatic parameters, error metrics, including Mean Absolute Error (MAE), Maximum Absolute Error (MaxAE), Mean Square Error (MSE), Root Mean Square Error (RMSE), and Standard Deviation (STD) are analysed and compared with the conventional approaches. The comparative outcomes highlight the minimal error metrics of a suggested MLA for temperature, humidity, and CO₂ levels in blooming plants. The result analysis proves that the proposed MLA model is better than the previous models for predicting the proper range of CO₂ concentration, suitable temperature, and perfect humidity for flowering plants. This demonstrates the effectiveness of the proposed MLA approach compared to the established methods for developing blooming plants.

Massive thermal effluent energy from power plant is mostly released to the sea, and only a little is used for fishing culture and agriculture in South Korea. The thermal effluent from the power plant can be an efficient heat source of the heat pump system to provide heating energy for the greenhouse, but energy loss and pump power by long distance pipeline installation from a power plant to the greenhouse should be considered. In this paper, an operational energy saving potential of a thermal effluent source heat pump system for the greenhouse heating was investigated. For the estimation of thermal load, three cases of greenhouse were categorized, and the thermal performance and operating energy consumption during the heating season were compared with those of a conventional ground source heat pump (GSHP) system. The model for heat pump system was newly derived to estimate the energy performance of the proposed system, and then detailed simulations for each system under three cases of greenhouse were conducted. The results showed that the operational energy of the proposed system can be saved by 17–20% than that of the conventional GSHP system.

Inside a greenhouse, during the day, the temperature rises very quickly, while the plants have to face temperatures that rise to more than 35${}^{\circ }$C. The plant closes its pores to limit sweating and stops growing. As soon as it gets hot, it is therefore necessary to ventilate the greenhouse. In this context, this research aims to investigate the behavior of the natural ventilation on the internal climate of the tunnel greenhouse, which contains two openings in the roof. The effect of the position of the openings on heat transfer is considered, thus promoting photosynthesis and plant growth. The vorticity transport equation, the Poisson equation and the energy equation are discretized by using the finite volume method. Two-dimensional simulations that described laminar flows in a steady state were carried out. Flows are studied for a range of parameters: the Rayleigh number, Ra, $10^3\le \mathrm{\text{Ra}}\le 10^6$, and three positions of opening ventilation. The results reveal that the ventilation through the top opening position allows the best creation of heat exchanges between the air inside the greenhouse and its atmosphere, which serves to conserve the plant under a favorable climate that allows its growth.

Industrial integration becomes more and more attractive to practitioners in industry, and draws a lot of attention from academia as well. However, the discussion of industrial integration is inconsistent, diversified, and targeted at different prospects. This paper attempts to address a systematic and comprehensive review on 74 articles about industrial integration from 2006 to 2016 in the SCI/SSCI database, in order to present an overview to researchers and practitioners. We will clarify current trends and main findings, and framework, strategies, and case analyses as well. The selected papers are diversified into seven research potential outlets. Summarization and research directions for each outlet are examined. Depending on the selected articles, European countries are the major contributed countries focusing on practical or technological issues regarding industrial integration.

As greenhouse production is considered the most water-conservative solution in the agricultural sector, greenhouse technology has become an integral approach for modern crop production methods. Different types of greenhouse structures are used to produce crops, and each type has advantages for a particular application, having been designed to meet multiple and specific requirements. This paper introduces a quality function deployment (QFD) framework to select two optimal greenhouse types (single-span and multi-span). This study aims to demonstrate greenhouse management and practices and review the development efforts during the last two decades. A market survey, focus group discussion, and personal interviews revealed nine key performance indicators (KPIs) (cost, wind loads, crop loads, roof slope, light transmission, flexibility, maintainability, rapid spread/ease of control, and heating and ventilation). Then, the participating decision-makers identified nine functional requirements, which, if fulfilled, would boost client satisfaction. The framework designed in this paper was developed to select and analytically investigate the optimal system for greenhouse microclimate control based on the retrieved KPIs and functional requirements for client satisfaction. This QFD framework can assist decision-makers, in the preliminary phase, in selecting optimal systems for greenhouse microclimate control based on their individualized situations.

In digital era, almost everything is being automated with the aim of replacing hand-operated systems. In recent years, intelligent sensor systems are being used tremendously in agriculture. This witnesses the importance of Smart Greenhouse in the field of agriculture. In this field, a variety of sensors and technologies are used for remote monitoring and vision controlling. With these technologies, farmers instead of monitoring by seeing in the greenhouse for hours and hours, can stay home and control sensors online. By using these technologies one can easily monitor plant growth state in real-time. In this paper we develop a vision- and sensor-based control system for Smart Greenhouse. The main objective of this paper is to develop a multi-functional, easy to control, microcontroller-based system to monitor and record the measured values/metrics of environmental parameters such as temperature, humidity, soil moisture, and air quality of the Greenhouse. The environmental parameters are continuously modified and controlled by the system in order to optimize them in view of achieving maximum plant growth and yield/supply.

The objective of this study is to improve agricultural water use efficiency and promote water-efficient substrate cultivation in greenhouse rapid development. A precision irrigation decision system was designed using single - chip microcomputer and sensor technology based on the crop biological principles, it includes a central control system, temperature and humidity sensors, PAR (photosynthetically active radiation) sensor, substrate moisture sensors, pump and solenoid valves, this system realize the automatic irrigation control based on the coupling action of the crop root growth, the substrate water transport and a optimum range of substrate water content. The experiment results in greenhouse show that the system has the ability to develop a scientific and rational irrigation decision and make full use for irrigation water.