Efficient Temperature Control Research Articles

Effect of High Incubation Temperature on the Blood Parameters of Layer Chicks

ABSTRACT Adequate environmental temperature control is essential for incubation efficiency. Layer breeder eggs (n=360) were weighed and distributed in a completely randomized experimental design with two treatments, consisting of two incubation temperatures (T1=37.5 °C, control; and T2=39.0 °C, hot), with two incubators per temperature, and 90 eggs per incubator, totaling 360 eggs. Hatchability, embryo mortality, and chick cloacal and body surface temperatures were not affected by incubation temperature. Eggs incubated at the hot temperature presented greater egg mass loss and higher eggshell conductance than those incubated at the control temperature. Layer chicks derived from eggs incubated at control temperature showed greater absolute weight, yolk-free egg mass, and heavier hearts than those from eggs submitted to heat stress during incubation. The control group presented lower base excess and ionized calcium blood levels. Incubating eggs at temperatures higher than those recommended compromises body and heart development of layer chicks and negatively affects blood ionized calcium availability, and therefore, bone mineralization during embryo development. Efficient temperature control during the incubation of fertile eggs is essential to obtain good quality layer chicks.

IoFClime: The fuzzy logic and the Internet of Things to control indoor temperature regarding the outdoor ambient conditions

The Internet of Things is arriving to our homes or cities through fields already known like Smart Homes, Smart Cities, or Smart Towns. The monitoring of environmental conditions of cities can help to adapt the indoor locations of the cities in order to be more comfortable for people who stay there. A way to improve the indoor conditions is an efficient temperature control, however, it depends on many factors like the different combinations of outdoor temperature and humidity. Therefore, adjusting the indoor temperature is not setting a value according to other value. There are many more factors to take into consideration, hence the traditional logic based in binary states cannot be used. Many problems cannot be solved with a set of binary solutions and we need a new way of development. Fuzzy logic is able to interpret many states, more than two states, giving to computers the capacity to react in a similar way to people. In this paper we will propose a new approach to control the temperature using the Internet of Things together its platforms and fuzzy logic regarding not only the indoor temperature but also the outdoor temperature and humidity in order to save energy and to set a more comfortable environment for their users. Finally, we will conclude that the fuzzy approach allows us to achieve an energy saving around 40% and thus, save money.

Experimental and CFD Study of a Vertically Stirred Tubular Reactor Designed for Suspension Polymerization Reactions

A vertically stirred tubular reactor is designed and studied in this work to perform the styrene batch suspension polymerization. Computational fluid dynamic techniques are applied to acquire information regarding the heat transfer and fluid flow behavior along the reactor. The simulated findings are used to support the experimental results (particle size distribution—PSD) obtained by varying the stirring system configuration, stabilizing agent concentration, and system holdup (styrene/water ratio v/v). According to the results, an efficient temperature control is attained due to the tubular geometry of the equipment. In addition, the PSD broadens by increasing the size of the shaft and the number of impellers installed along the reactor. An evaluation of the particle sedimentation throughout the reaction demonstrates that the PSD and the stirring rate play an important role in the sedimentation kinetics. Such findings demonstrate the potential of the proposed reactor to be explored in order to perform suspension polymerizations semicontinuously or continuously by applying suitable operation strategies. image

Development and examination of switchable heat pipes

The well-directed transmission of heat flux enables an efficient and demand-actuated temperature control of technical systems. By the combination of heat pipes and shape memory alloy actuators, an adaptive, passively working switch concept is developed and implemented, which automatically activates the heat flux through the heat pipe when reaching a certain temperature limit. Furthermore, the created numerical calculation model provides the opportunity to theoretically describe the behavior of the designed system. Measurements show the proof of the concept and validate the model for further optimizations of switchable heat pipes to be applied in various technical applications.

Localized self-heating in large arrays of 1D nanostructures.

One dimensional (1D) nanostructures offer a promising path towards highly efficient heating and temperature control in integrated microsystems. The so called self-heating effect can be used to modulate the response of solid state gas sensor devices. In this work, efficient self-heating was found to occur at random networks of nanostructured systems with similar power requirements to highly ordered systems (e.g. individual nanowires, where their thermal efficiency was attributed to the small dimensions of the objects). Infrared thermography and Raman spectroscopy were used to map the temperature profiles of films based on random arrangements of carbon nanofibers during self-heating. Both the techniques demonstrate consistently that heating concentrates in small regions, the here-called "hot-spots". On correlating dynamic temperature mapping with electrical measurements, we also observed that these minute hot-spots rule the resistance values observed macroscopically. A physical model of a random network of 1D resistors helped us to explain this observation. The model shows that, for a given random arrangement of 1D nanowires, current spreading through the network ends up defining a set of spots that dominate both the electrical resistance and power dissipation. Such highly localized heating explains the high power savings observed in larger nanostructured systems. This understanding opens a path to design highly efficient self-heating systems, based on random or pseudo-random distributions of 1D nanostructures.

Design and evaluation of hybrid temperature control for cyber-physical home systems

The design of control systems is crucial for improving the comfort level of the home environment. Cyber-physical systems (CPSs) can offer numerous opportunities to design highly efficient control systems. In this paper, we focus on the design and evaluation of temperature control systems. By using the idea of CPS, a hybrid temperature control (HTC) system is proposed. Through an energy efficient temperature control (EETC) algorithm, the HTC system maintains the room temperature in the desired interval. In the tight integration of physical and cyber worlds, the sensing accuracy of the physical platform has significant impact on the performance of the HTC system. Through simulations and field experiments, the relationship between control performance and sensing accuracy is captured. A fitting function method is proposed to improve the sensing accuracy without increasing the monetary cost of the system implementation. By using this method, the performance of the HTC system can be increased significantly.

High-Efficiency Applicator Based on Printed Circuit Board in Millimeter-Wave Region

The purpose of this study is to develop a novel in vitro millimeter-wave (MMW) applicator for an exposure apparatus that allows high power efficiency with reasonably good homogeneity over a sufficient exposure area, as well as the capability of temperature control in biological samples. The applicator is made of a printed circuit board and has a large and circular (90-mm diameter) exposure area that is fed with MMWs using post-wall waveguide technology. The applicator is designed for the exposure of cells to MMWs at 60 GHz. The proposed applicator has an absorption efficiency of 54%, where the absorption efficiency is defined as the ratio of the total power absorbed in the culture medium to the input power. Its efficiency is higher than those of other apparatuses operating at 60 GHz reported in the literature. Most of the cells (89%) are located within the $\pm {\hbox{5-dB}}$ region relative to the average specific absorption rate, which shows reasonably good homogeneity compared with previously reported literature data. The applicator enables efficient temperature control for in vitro experiments to explore unknown and possible nonthermal effects of MMW exposures.

CFD modeling of compact methanol reformer

The compact fuel processor that uses methanol as a feedstock for the production of hydrogen and for temperature control was studied by computational fluid dynamics. The processor integrates in a single package the methanol–water evaporator, the gas flow distributors, the steam reformer and the methanol–air catalytic combustor. The reformer and the combustor were formed as tubular reactors that possessed a single metallic body like a monolith with an array of circular cross-section through-holes. Part of holes was filled with reforming catalyst and the other part was filled with a catalyst for the oxidation of methanol.The design provides efficient heat transfer between the reformer and the combustor and efficient temperature control of the reformer. The temperature distribution in the metallic body of the reformer and the combustor is almost uniform. The value of temperature nonuniformity does not exceed the value ΔT=2.4% in any cross-section of the reaction zone.Maximum overall effectiveness of the fuel processor is achieved at the value of methanol feed equal 17.24mmol/min (GHSV=12,424h−1) and 8.75mmol/min (GHSV=16,632h−1) in the reformer and in the combustor, respectively. Under these conditions the hydrogen performance is equal to 70.0l/h (48.7mmol/min) and the temperature is equal to 286.4°C in the reformer.

Building Indoor Temperature Control Using Model Predictive Control in Cooling Systems

In this paper, an energy efficient temperature control algorithm with a photovoltaic (PV) system in cooling systems of a large glass-covered building is proposed using control horizon method. A control horizon switching method and linear programming algorithm is used for optimal control, and a time-of-use (TOU) electricity rate is included to calculate the energy costs. Simulation results show that the reductions of energy cost and peak power can be obtained using proposed algorithms.

Assessing thermal comfort and energy efficiency in tropical African offices using the adaptive approach

Purpose – The purpose of this paper is to adduce the most appropriate thermal comfort assessment method for determining human thermal comfort and energy efficient temperature control in office buildings in tropical West Africa. Design/methodology/approach – This paper examines the Adaptive Thermal Comfort Standard, from its research evolution to its contemporary use as an environmental design assessment Standard. It compares the adaptive component of ASHRAE Standard 55 and the European CEN/EN 15251. It begins by reviewing relevant literature and then produces a comparative analysis of the two standards, before suggesting the most appropriate Adaptive Thermal Comfort Standard for use in assessing conditions in tropical climate conditions. The suggested Standard was then used to analyse data collected from the author's pilot research into thermal conditions, in five office buildings situated in the city of Enugu, South Eastern Nigeria. Findings – The paper provides insight as to why the ASHRAE adaptive model is more suitable for thermal comfort assessment of office buildings in the tropical West African climate. This was demonstrated by using the ASHRAE Thermal Comfort Standard to assess comfort conditions from pilot research study data collected on Nigerian office buildings by the author. Originality/value – The paper compares the adaptive component of ASHRAE Standard 55 with CEN/EN 15251, and their different benefits for use in tropical climates. It suggested the need for further research studies and application of the ASHRAE Adaptive Thermal Comfort Standard in the tropical West African climate.

Safe Palladium-Catalyzed Cross-Couplings with Microwave Heating Using Continuous-Flow Silicon Carbide Reactors

Herein we present a 200 mm × 3 mm Øi silicon carbide (SiC) tube reactor for use in a commercially available microwave heated continuous-flow system. The SiC flow reactor enables palladium(0)-catalyzed reactions that, due to precipitation and subsequent hot spot formation, often followed by reactor failure, are unsuitable to conduct in standard microwave-transparent borosilicate glass reactors. We report continuous-flow protocols for the Mizoroki–Heck reaction (10 examples, 81–86% yield) as well as the Suzuki–Miyaura cross-coupling (14 examples, 70–87% yield), showing the utility of the SiC reactor. Furthermore, we performed a scale-out of the NSAID biphenylacetic acid, achieving outputs of 14 mmol/h of the Suzuki–Miyaura reaction, and a 72% overall yield over three steps. The SiC reactor enabled fast and efficient temperature control, high robustness, and easy maintenance.

Self Tuning Based Adaptive Fuzzy Logic Controller in Lab view for Sterilizing Equipments

In this paper, temperature monitoring of sterilizing equipment system was established with the help of fuzzy and self tuning Adaptive fuzzy logic controller designed in Lab VIEW software. It combines the advantages of both fuzzy logic and self tuning Adaptive fuzzy logic controller. The implementation attempts to rectify the errors between the measured value and the set point which helps to achieve efficient temperature control. The Adaptive fuzzy controller uses defined rules to control the system based on the current values of input variables and temperature errors. The simulation results presented in order to evaluate the proposed method. The result shows that self tuning Adaptive fuzzy logic controller was tolerant to disturbance and the temperature control is most accurate.

LABVIEW BASED SELF TUNING FUZZY LOGIC CONTROLLER FOR STERILIZING EQUIPMENTS IN HOSPITALS

In this paper, temperature monitoring of sterilizing equipment system was established with the help of fuzzy and self tuning fuzzy logic controller designed in LabVIEW software. It combines the advantages of both fuzzy logic and self tuning fuzzy logic controller. The implementation attempts to rectify the errors between the obtained value and the given point which helps to achieve efficient temperature control. With the help of the rules the fuzzy controllers manage the system depend on the obtained values and the difference in the both temperature (errors). The simulation results presented in order to evaluate the proposed method. From the result the self tuning fuzzy logic controller was forbearing to any kind of interruption and the temperature control is most accurate.

Design of a Bubbling Fluidized Bed Gasifier for the Thermochemical Conversion of Oil Palm Empty Fruit Bunch Briquette

This paper is focused on the design of a bubbling fluidized bed gasifier (BFBG) for EFB briquette gasification. The annual production of palm oil in Malaysia generates large quantities of lignocellulosic biomass which can be converted into clean, sustainable energy for the future. Hence, the prospect of valorising palm waste using biomass gasifiers presents a viable option for energy production. The fluidized bed gasifier (FBG) is considered the most suitable reactor for biomass gasification due excellent mixing, efficient heat temperature control and tolerance for fuels. Consequently, the proposed design of the bubbling fluidized bed gasifier for EFB briquette gasification will consist of three main parts; feeding zone, gasification zone and the effluent gas zone for syngas production. The results of feedstock physicochemical properties such as bulk density, particle size, the bed hydrodynamic and fluidization parameters for gasification used in the design of the gasifier are presented in this paper.

Energy Efficient Temperature Control for Peak Power Reduction in Building Cooling Systems

In this paper, an energy efficient temperature control algorithm for peak power reduction in cooling systems of a large glass-covered building is proposed using control horizon method. A control horizon switching method and linear programming algorithm is used for optimal control, and a time-of-use (TOU) electricity rate is included to calculate the energy costs. Simulation results show that the reductions of energy cost and peak power can be obtained using proposed algorithms.

A comparative study of ultrasound-, microwave-, and microreactor-assisted imidazolium-based ionic liquid synthesis

Abstract Synthesis of ionic liquid 1-heptyl-2,3-dimethylimidazolium bromide was accomplished with the assistance of ultrasound, microwave irradiation, and a continuously operated microreactor and was compared with a conventional laboratory scale process applying magnetic stirring and water-bath heating. Results were compared with respect to process productivity, energy consumption, and product colourisation as an indicator of its purity. By using nonconventional technologies, volumetric productivity was 10- to 30-fold superior, while energy consumption was reduced by 45%–65%. Among the alternatives tested, ultrasound-assisted synthesis was shown as the most efficient one in terms of volumetric productivity (4.40 mol l-1 h-1) and specific power consumption (909.1 W h mol-1), while microwave-assisted process was the least favourable. However, only a microreactor system enabled the synthesis of a noncoloured product resulting from very efficient mixing and temperature control. Due to significant process intensification along with high product quality and superior industrial perspectives, a continuous quaternisation within microchannels could be selected as the most promising green approach among the alternatives tested in this study. Integration of ultrasound and microreactor technology including miniaturised heat exchanger is foreseen for process intensification.

Off-Line Robust MPC Algorithm for VAV Air-Conditioning Systems

The efficient temperature control of variable air volume (VAV) air-conditioning system can greatly reduce the energy consumption. In order to due with system constraints and uncertainties, and guarantee the closed-loop stability, an off-line min-max robust model predictive control algorithm is presented for the temperature control of a VAV system. As the first-order-plus-time-delay model of system is described by a polyhedral described uncertain model, the off-line ellipsoidal invariant set based robust MPC algorithm is employed for the controller design. Simulation results show efficiency of the proposed control algorithm implemented in the temperature control of a VAV system, which can enhance robustness, and satisfy the constraints.

Development of spin-exchange relaxation free magnetometer with a compact heating system

Atomic magnetometers based on spin-exchange relaxation free (SERF) regime typically operate with the high optical density and low magnetic fields. We present SERF magnetometer with a compact heating system for compact and efficient temperature control. A resistive heating system with high frequency alternating current was used to achieve high optical density. The current frequency was carefully chosen to avoid resonance with the atomic magnetometer. This resulted in a compact heating system that also allows independent operation of multiple heating systems. Optical rotation signal was obtained at 200 <sup>o</sup>C and width was about 3 nT with pump laser power of 55 mW. Bandwidth of the magnetometer with the compact heater was 40 Hz. Consequently, the compact resistive heating system proved to be a good alternative to the air-flow heating system. Additionally, residual field effect and signal-to-noise yielded a sensitivity of 50 fT/Hz<sup>1/2</sup> at 10 Hz. <br />

Design of a Magnetic Resonance Imaging Compatible Metallic Pressure Vessel

High-pressure measurements in most scientific fields rely on metal vessels, a consequence of the superior tensile strength of metals. Magnetic resonance imaging in conjunction with metallic pressure vessels has recently been introduced. Magnetic resonance imaging with compatible metallic pressure vessels is a very general concept. This paper outlines the specifics of the development and design of these vessels. Metallic pressure vessels not only provide inherently high tensile strengths and efficient temperature control, they also permit optimization of the radio-frequency probe sensitivity. The design and application of magnetic resonance imaging compatible pressure vessels is illustrated through a rock core holder fabricated using nonmagnetic stainless steel. Water flooding through a porous rock at elevated pressure and temperature is shown as an example of its applications. High-pressure magnetic resonance plays an indispensable role in several scientific fields; this work will open new avenues of investigation for high-pressure material science magnetic resonance imaging.

Energy Efficient Temperature Control with Particle Swarm Optimization for Smart Buildings

In this paper, the energy efficient temperature control algorithm in smart buildings is proposed using particle swarm optimization (PSO). A control horizon switching method with PSO is used for optimal control, and the TOU tariff is included to calculate the energy costs. Simulation results show that the reductions of energy cost and peak power can be obtained using proposed algorithms.