IR Emitter Research Articles

Разработка устройства для обеззараживания ИК-излучением почвосмеси в тонком слое на конвейере

Pest and disease control in the cultivation of greenery is an integral part of obtaining a high-quality and high yield. Heat treatment is one of the best ways to combat plant diseases and pests and allows you to quickly create the necessary sterile conditions without the use of chemicals. A device for disinfection of soil mixtures in a thin layer by IR radiation on a conveyor is being developed for heat treatment. The prepared soil mixture from the feed hopper enters the conveyor belt in a thin layer. An IR emitter with adjustable power is installed above the conveyor belt. The movement of the conveyor belt should ensure heating in the soil mixture layer up to 100 ± 5 ° C. This is controlled by a temperature sensor, which sends a signal via a programmable relay to the conveyor motor and regulates its movement. The disinfection process allows to achieve high energy efficiency due to software regulation, taking into account optimal modes and control of the processing temperature. Keywords: DISINFECTION, IR RADIATION, HEATING, SURFACE, SOIL MIXTURE, DISEASES, PESTS, CONVEYOR

Winding process of fibre-reinforced thermoplastic tubes with integrated tape production through in-situ roving impregnation and infrared consolidation

This paper introduces a novel method for producing fibre-reinforced thermoplastic tubes by integrating tape production and consolidation into a single operation. This innovation diverges from conventional methods by combining processes to reduce costs by using raw materials instead of organotapes, allowing customised material combinations and utilising residual heat from tape production. The new process uses carbon roving and molten low-viscosity PA6 granulates, processed through a new direct impregnation setup in siphon design. Key advancements include a high-speed impregnation module capable of up to 1 m/s with high-performance extruders, cost-effective infrared emitters for winding, and a powered consolidation unit with adjustable winding angles between ± 65° and ± 90°. Experiments demonstrate operational speeds of approximately 471 mm/min, with an optimal cross-winding speed of 354 mm/min due to the technical limitations of the laboratory extruder and IR emitter used. Based on the technical limitations of the current system, future improvements and methodological changes will be discussed.

P‐206: Key factor of Device Lifetime in Exciplex Host Based Blue Phosphorescent Organic Light Emitting Diodes

In this study, we investigated the key factor of device lifetime in blue phosphorescent organic light emitting diodes (PhOLEDs) by managing hosts and dopants in the emitting layer. We manufactured four phosphorescent devices using the exciplex type mixed host and single bipolar host doped with either Pt type and Ir type phosphors. The mixed host was better than single host in the Pt emitter doped device, while it was similar to the single host in the Ir emitter doped device. Investigation of the light‐emission mechanism of the PhOLEDs revealed that the mixed host is essential in the device showing strong hole trapping behavior. The strong p‐type host in the mixed host relieves the hole trapping by the Pt phosphor, resulting in less polaron formation and polaron accumulation. As a result, the mixed host reduces triplet‐polaron annihilation and extends the device lifetime of the Pt emitter doped PhOLEDs.

Методика исследования обеззараживания ИК-излучением почвосмеси в тонком слое на конвейере

Growing greens is always accompanied by the development of pests and diseases, the fight against which is an integral part of obtaining a high and high-quality harvest. Heat treatment is one of the best ways to combat plant diseases and pests. Allows you to quickly create the necessary sterile conditions without the use of chemicals. For heat treatment, a device is being developed for disinfecting soil and substrate in a thin layer using IR radiation on a conveyor belt. The prepared soil mixture from the supply hopper falls onto the conveyor belt in a thin layer. An IR emitter with adjustable power within the range of 4...10 kW is installed above the conveyor belt. The movement of the conveyor belt should ensure that the surface of the soil mixture is heated to 100 °C. This is controlled by a temperature sensor, which sends a signal via a programmable relay to the conveyor motor and regulates its movement. The disinfection process makes it possible to achieve high energy efficiency through software regulation, taking into account optimal modes and control of the processing temperature. Keywords: DISINFECTION, IR RADIATION, HEATING, SURFACE, PROGRAM CONTROL, SOIL MIXTURE, DISEASES, PESTS

(Invited) Understanding Plasma-Assisted Atomic Layer Epitaxy of InN and Opportunities for Collaboration through the Office of Naval Research Global

The family of III-V nitride compound semiconductors has provided the foundation to a number of advanced electronic device technologies from light emitting diodes to radio frequency transistors to power switches. Of the family, binary indium nitride (InN) and ternaries/quaternaries containing InN have progressed at a slower pace due the material properties and related growth challenges. Having the weakest bonds in the family, the material has a lower melting point and more easily decomposes and phase separates (in ternaries and quaternaries). As such, a number of research efforts are looking for new growth approaches to overcome these challenges and realize the InN-based materials that will enable devices such has high speed switches and IR emitters and detectors.To this end, plasma-assisted atomic layer epitaxy (PA-ALE) of InN and InN-containing ternaries has been explored in recent years. Much like atomic layer deposition, ALE consists of a sequence of self-limiting surface half-reactions that promotes “layer-by-layer” growth of films. The cyclical growth process starts with exposure of the growth surface first to the group III precursor (trimethylindium, for example), then purging excess precursor and reaction byproducts leaving only the ad-/physi-/chemi-sorbed species on the surface. After this purge, these surfaces are then exposed to a collection of plasma species (ions, radicals, neutrals, etc.) which reacts with the “sorbed” layer. The growth cycle is finished with a purge of the surface reaction by-products and unreacted plasma species before repeating. The potential of the process is based on the premise that by providing energy from plasma species to the growth surface, one can lower the temperature of growth to improve the stability of the material. Further, the reactive neutral plasma species also play a role by lowering activation energies for chemical reactions compared to thermal ALD, without necessarily providing energy to the growth surface.A brief review of previous experimental demonstrations of epitaxial growth of InN and InN-containing ternaries will be presented showing the promise of the growth method to grow quality InN binary films and metastable ternaries containing InN not possible by conventional growth methods. For example, a metastable cubic phase of InN (NaCl) was realized as were ternary stoichiometries for both InAlN and InGaN that lie in the thermodynamic miscibility gap. Further, and in an effort to begin to understand this growth process and the role that plasma might play in growth mechanisms, synchrotron-based studies have been employed during growth of binary InN and digital InAlN and InGaN alloys. The results of these studies will be highlighted and key findings identified. Most recently, coherent x-ray scattering has been employed to provide additional insights including surface diffusion during each step of the cyclical growth process. The cumulative findings of these efforts will be presented, and future directions outlined.As the presenting author is now detailed as a Science Director for Power & Energy and Advanced Materials to the U.S. Office of Naval Research Global in London, the last portion of the talk will be dedicated to introducing ONRG and its mission to engage international researchers through research grants, travel grants and conference support. The hope is to increase awareness of collaborative opportunities to the global research community expected to be in attendance.

Precise characterization of IR emitters

AbstractSpectroradiometers are the key component for a wide range of light measurement tasks in many innovative applications. Radiometric, photometric and colorimetric properties are calculated from their spectral data with the aid of extensive software suites, such as SpecWin Pro. Their precision and accuracy are therefore especially important for exact readings.

Development of a novel non-water infrared refractance window drying method for Malabar spinach: Optimization of process parameters using drying kinetics, mass transfer, and powder characterization

In the present work, a novel non-water Infrared Refractance Window drying (IR-RWD) method was developed for Malabar spinach. Experiments were conducted using a hybrid experimental design. Fresh Malabar spinach was pretreated using the vacuum steam pulsed blanching (VSPB) method. Results showed that VSPB inactivated POD and PPO activities to 9.77% and 5.42% within four cycles, respectively. The optimum conditions were found at 1.2 mm sample thickness, 40% infrared power, and 3.67 cm distance between IR emitter and glass plate resulting in 67.38 % chlorophyll retention, 7.72 overall color changes, 16.57 mgGAE g−1 total phenolic content, and 11.20 kJ kg−1 specific energy consumption. The Page model showed the best fit to the drying kinetics. Furthermore, Biot number indicated the impact of both internal and external resistance on moisture diffusivity. XRD and FESEM characterization of dried powder showed a semi-crystalline phase and square plate, porous morphology. The non-water IR-RWD was a promising alternative to traditional water RWD.

Peripheral engineering of Ir(iii) emitters with imidazo[4,5-b]pyrazin-2-ylidene cyclometalates for blue organic light emitting diodes

A new class of Ir(iii) carbene complexes with dual N-aryl appendages, the isomeric products of which were successfully isolated and purified by column chromatography, were synthesized followed by catalytic isomerization at elevated temperature.

Theoretical exploration of the electronic structure and photophysical properties of five cyclometalated Ir(III) complexes bearing different substituted acetylacetone moieties

Using time-dependent density functional theory (TDDFT) approach, the electronic structure and photophysical properties of five cyclometalated Ir(III) complexes bearing different substituted acetylacetone moieties have been calculated and investigated. The calculated geometry structure of complex 2 shows a very good agreement with the available experimental data. The HOMO of complex 1 has the different distribution from those of complexes 2–5, that is, residing on the d-orbital of Ir, π-orbital of acac and L ligands. The S0 → S1 transition of complex 1 is from HOMO → LUMO and HOMO–1 → LUMO, that is, different from those of complexes 2–5. The lowest energy emissions for these complexes from CAM-B3LYP level are localized at 591, 581, 576, 574, and 571, respectively. Complex 4 might possess the largest kr value among these studied complexes. We anticipate that this study can shine some light on Ir(III) emitters in the fabrication of efficient organic light-emitting diodes (OLEDs).

Parameters of Agricultural Product Dryer

The problem of drying quality in existing installations is considered. It is proposed to carry out the analysis of heat and moisture transfer in the Comsol complex. As a result of modeling, dependences of changes in temperature and moisture content of raw materials on time were obtained. A rational geometry of the location of the dryer trays and the addition of convective heating with an IR emitter are recommended, which contributes to the formation of a more uniform moisture content of the dried product and a reduction in the process time.

Excited-State Modification of Phenylimidazole-Based Cyclometalated Ir(III) Complexes through Secondary Bulky Aryl Substitution and Inductive Modification Enhances the Blue Emission Efficiency in Phosphorescent OLEDs

To elucidate the key parameters governing the emission properties of phenylimidazole (pim)-based Ir(III) emitters, including their electronic structure and the bulky aryl substitution effect, a series of pim-based iridium(III) complexes (Ir(Rpim-X)3, Rpim-X = 1-R-2-(X-phenyl)-1H-imidazole) bearing secondary pendants of increasing bulkiness [R = methyl (Me), phenyl (Ph), terphenyl (TPh), or 4-isopropyl terphenyl (ITPh)] and three different primary pim ligands (X = F, F2, and CN) were designed and synthesized. Based on photophysical and electrochemical analyses, it was found that the excited state properties are highly dependent on the bulkiness of the secondary substituent and the inductive nature of the primary pim ligand. The incorporation of bulky TPh/ITPh substituents in the second coordination sphere significantly enhanced the emission efficiencies in the solid state (ΦPL = 72.1-84.9%) compared to those of the methyl- or phenyl-substituted Ir(III) complexes (ΦPL = 30.4% for Ir(Mepim)3 and 63.7% for Ir(Phpim)3). Further modification of the secondary aryl substituent (Ir(TPhpim)3 → Ir(ITPhpim)3) through the incorporation of an isopropyl group and F substitution on the primary pim ligand (Ir(TPh/ITPhpim)3 → Ir(TPh/ITPhpim-F/F2)3) resulted in a slight decrease in the LUMO and a significant decrease in the HOMO energy levels, respectively; these energy level adjustments consequently amplified emission blue shifts, thereby enabling efficient blue electroluminescence in phosphorescent organic light-emitting diodes. Theoretical calculations revealed that the excited-state properties of pim-based Ir(III) complexes can be modulated by the nature of the peripheral substituent and the presence of an EWG substituent. Among the fabricated blue-emitting TPh/ITPh-substituted Ir(III) complexes, Ir(ITPhpim-F)3, Ir(TPhpim-F2)3, and Ir(ITPhpim-F2)3 were tested as blue-emitting dopants for blue phosphorescent OLEDs owing to their high solid radiative quantum yields (ΦPL = 75.9-84.9%). The Ir(ITPhpim-F)3-doped multilayer device displayed the best performance with a maximum external quantum efficiency of 21.0%, a maximum current efficiency of 43.6 cd/A, and CIE coordinates of 0.18 and 0.31.

Lanthanide Luminescence and Thermochromic Emission from Soft-Atom Donor Dichalcogenoimidodiphosphinate Ligands

The luminescence properties of two divalent europium complexes of the type Eu[N(SPPh2)2]2(THF)2 (1) and Eu[N(SePPh2)2]2(THF)2 (2) were investigated. The first complex, Eu[N(SPPh2)2]2(THF)2 (1), was found to be isomorphous with the reported structure of complex 2 and exhibited room temperature luminescence with thermochromic emission upon cooling. We found the complex Eu[N(SePPh2)2]2(THF)2 (2) was also thermochromic but the emission intensity was sensitive to temperature. Both room temperature and low temperature (100 K) single crystal X-ray structural investigation of 1 and 2 indicate geometric distortions of the metal coordination, which may be important for understanding the thermochromic behavior of these complexes. The trivalent europium complex Eu[N(SPPh2)2]3 (3) with the same ligand as 1 was also structurally characterized as a function of temperature and exhibited temperature-dependent luminescence intensity, with no observable emission at room temperature but intense luminescence at 77 K. Variable temperature Raman spectroscopy was used to determine the onset temperature of luminescence of Eu[N(SPPh2)2]3 (3), where the 615 nm (5D0 → 7F2 transition) peak was quenched above 130 K. The UV-visible diffuse reflectance of 3 provides evidence of an LMCT band, supporting a mechanism of thermally activated LMCT quenching of Eu(III) emitting states. A series of ten isomorphous, trivalent lanthanide complexes of type Ln[N(SPPh2)2]3 (Ln = Eu (3) Pr (4), Nd (5), Sm (6), Gd (7), Tb (8)) and Ln[N(SePPh2)2]3 (Ln = Pr (9), Nd (10, structure was previously reported), Sm (11), and Gd (12) for Q = Se) were also synthesized and structurally characterized. These complexes for Ln = Pr, Nd, Sm, and Tb exhibited room temperature luminescence. This study provides examples of temperature-dependent luminescence of both Eu2+ and Eu3+, and the use of soft-atom donor ligands to sensitize lanthanide luminescence in a range of trivalent lanthanides, spanning near IR and visible emitters.

Sputtering of GaAs target under Bim+ cluster ions bombardment

The yield of secondary ions and neutral Ga atoms, converted into positive ions on the surface of an Ir emitter was measured during the bombardment of a GaAs target with cluster ions Bim+ (m = 1–5) in the energy range 1–10 keV. A non-additive increase in the yield of secondary ions was observed with an increase in the number of atoms in the bombarding ions. An estimated calculation of the ionization probability of gallium during sputtering has been carried out. A decrease in the ionization probability with an increase in the number of atoms in the bombarding cluster ions was found.

Теоретичне обґрунтування типу променевих перетворювачів при ідентифікації зернового потоку

The article is devoted to the theoretical substantiation of the type of beam converters in the identification of grain flow in planters. The working conditions of beam transducers in the process of sowing grain crops, types and characteristics of such transducers are considered. It is shown that the best characteristics are possessed by optocouples created on the basis of independent sources and receivers of infrared radiation in the form of silicon diodes operating in the range of 0.75...1.1 μm. This publication is aimed at the implementation of means of control during the sowing of grain crops, its topic is relevant. It is directed to the implementation of the program "Technical means of the new generation for agricultural production", included in the list of State targeted scientific and scientific and technical programs, defined by the law of Ukraine "On priority areas of development of science and technology". The publication examines the theoretical justification of the type of beam transducers in devices for identifying the grain flow formed by seeding devices of seed drills, in order to increase their resolution and quality of registration of discrete objects in the flow. As a result of the analysis of the conditions for identifying the grain flow when sowing grain crops, we come to the conclusion that it is advisable to use optocouplers from separate elements "radiation source"-"radiation receiver" of the infrared spectrum that work in the range of as beam converters. Based on the fact that the registration device includes dozens of discrete optocouplers, silicon light and photodiodes should be used as IR emitters and receivers, as they are the cheapest, simpler in circuit connection than photo transistors and sufficient to obtain the necessary resolution when registering and recognizing the flow of grains.

Non-Dispersive Infrared Gas Sensing Technology: A Review

Non-dispersive infrared gas sensing (NDIR) is a unique optical sensing technique where IR radiation interacts with the targeted analyte and in the process, it is absorbed. This absorption is unique for every gas and hence, based on the absorption characteristics, gas molecules can be fingerprinted and distinctively identified. A simple NDIR gas sensor consists of an IR emitter, detector, optical filter, gas cell, and circuit elements for signal processing. Further, these components also offer choice for selection for example a microelectromechanical system (MEMS) based membrane heater, a light-emitting diode (LED), and IR lamp all have the capability of generating IR spectra. Similarly, a pyroelectric detector, photodiode, bolometer, as well as thermopile has the ability to detect IR rays. The choice of the selection of components carries advantages and disadvantages associated with them, and thus it is very important to choose them correctly for the targeted applications. This article reviews the evolution of non-dispersive infrared gas sensing techniques and the basic components of these sensors are discussed one-by-one. Finally, the shortcomings of the NDIR gas sensor have been summarized and the efforts made in recent times to cope with these are also discussed.

СЕЛЕКТИВНИЙ МЕТОД ТВЕРДНЕННЯ ЕПОКСИДНИХ СПОЛУЧНИКІВ ДЛЯ СТВОРЕННЯ ТОНКОСТІННИХ ВИСОКОМІЦНИХ КОНСТРУКЦІЙ

Purpose To improve the physical and mechanical characteristics of the epoxy composition, reduce energy consump-tion, cost, reduce production areas, as well as protect the environment, for the hardening thin-walled structures made of polymer composite materials, it is necessary to choose the most rational method for curing polymer composite materials. Methodology The prepared samples of the epoxy binder ЭДТ-10+УП606/2(1%) with a size of 10х10х10 mm, were hardened by convective, IR heating, and selective IR heating according to specified modes. IR heating is provided by unit with three halogen incandescent lamps type КГТ-220-1000-1 inside and using a salt filter. The mode of composition hardening according to three technologies has been developed. Findings The results of measurements of the cured samples showed that the highest microhardness was achieved using selective IR heating. Metallographic studies has shown that polymer obtained a compact structure with a high degree of hardening, approximately 97%. Hardened samples of ЭДТ-10 epoxy binder were subjected to mechanical tests. Having determined the microhardness, it was found that during the selective hardening of the ЭДТ-10 binder, the microhardness was 34,57 kgf/mm2, IR heating - 30,85 kgf/mm2, convective heating – 29,61 kgf/mm2. Originality To obtain the maximum specific power from the IR emitter, salt filters were used, in which the main part of the emitted energy fell on the wavelength (2,8 – 3,2)•10-6 м. This technique allows you to select the necessary frequency bands. Practicalvalue The results of epoxy composition samples hardening experiment showed that the hardening process by the IR heating selective method takes 1 hour and 15 minutes, in contrast to convective heating which requires at least 7 hours and IR heating with 2 hours and 30 minutes. The selective method provides a uniform temperature distribution over the entire surface to be treated, which ensures high physical and mechanical characteristics. Conclusions On the basis of experimental researches with help selective method IR of hardening samples from PCM have been received on the basis of epoxy binding which possess high mechanical durability and compact structure in comparison with a composition which hardening a traditional convection heating.

Survey on Optical Wireless Communications-Based Services Applied to the Tourism Industry: Potentials and Challenges.

In this paper, we explore the potential applications of Optical Wireless Communications in the tourism industry, considering both indoor and outdoor scenarios and different transmission speeds. They range from high-speed atmospheric outdoor links (Free-Space Optics (FSO)) to indoor systems based on high-speed lighting networks (known under the trade name LiFi©) or low-speed services support the Internet of Things networks, using visible light (VLC) or IR emitters, with receivers based on either on classical photodiodes or in image sensors, known as Optical Camera Communications. The avant-garde applications of this technology have been studied focusing on three possible use scenarios: the traveler himself, in what we have called TAN (Tourist Area Network); the tourist facility, which includes not only the hotel but also leisure areas (theme parks, museums, natural protected areas) or services (restaurants, shopping areas, etc.); and the entire destination, which can be both the city or the territory where the tourist is received, within the paradigm of the Smart Tourist Destination (STD). In addition to the classic services based on radio frequency and wired broadband networks, these technologies will make it possible to meet the tourist’s challenging needs, the establishment, and the destination. Besides, they cover the services imposed by the new marketing services related to location or context and feed the big data systems used to study tourist behavior.

The Architectonics Features of Heterostructures for IR Range Detectors Based on Polycrystalline Layers of Lead Chalcogenides

A model is developed for the formation of porous intragranular architectonics of nanostructured polycrystalline layers of lead chalcogenides for photodetectors and IR emitters. The layers are obtained under the conditions of thermal evaporation in a quasi-closed volume by the “hot wall” method followed by sensitizing heat treatment in an iodine-containing atmosphere. Model concepts are developed considering the experimental results of studying the intragranular structure of lead chalcogenides through original combined AFM methods over the cross-section of porous grains (cores) encapsulated by an oxide shell (lateral force microscopy and local tunneling I–V spectroscopy).

Iridium(III) complexes with 1-phenylisoquinoline-4-carbonitrile units for efficient NIR organic light-emitting diodes

SummaryAchieving the high external quantum efficiency (EQE) of near-infrared (NIR) emission in iridium(III) complexes still remains a challenge owing to their unsteady excited states which easily decay to the ground states through the nonradiative pathways. Herein, three Ir(III) phosphors in which the cyclometalated ligand 1-phenylisoquinoline-4-carbonitrile (piq-CN) is functionalized with the cyano, tert-butyl, and dimethyl groups are developed (CN-CNIr, Bu-CNIr, and DM-CNIr, respectively). Three simple synthetic steps can afford this class of deep red to NIR Ir(III) emitters. The organic light-emitting diodes (OLEDs) based on Bu-CNIr and DM-CNIr attain the maximum EQEs of 7.1% and 7.2% with the emission peaks at 695 and 714 nm, respectively. This strategy using substituted piq-CN derivatives as the cyclometalated ligands can offer an effective approach to promote the radiative rate of NIR-emitting Ir(III) materials. An insight into how the electron-withdrawing and electron-donating substituents on ligands influence the optoelectronic properties of their Ir(III) complexes is also provided.

A new drying approach deploying solid-solid phase change material: A numerical study

Recently, phase change materials are emerging in thermal drying technology. This study offers a new approach in thermal drying of a moist paper sheet deploying solid-solid phase change material, tentatively as an alternative to solid-liquid micro-encapsulated PCMs uniformly dispersed inside the void part of porous sheet. In contrast to SL-MEPCM scenario, SS-PCM is fabricated in solid matrix of porous medium, remaining the sheet porosity intact. Additionally, comparing to its SL-MEPCM counterpart, any costly PCM encapsulation process or change in the design of headbox of commercial paper machine is avoided. As well, volume change during phase transition is negligible. This configuration is particularly ideal for drying applications where a low porosity, initially highly moist sheet is to be dried. A numerical experiment is carried out to investigate the dewatering behavior of SS-PCM fabricated paper in a drying process. A real shape-stabilized polymeric SS-PCM is used in this study. A pattern search optimization technique is employed to minimize the target moisture content. This study shows SS-PCM primarily becomes effective in last stage of drying where it internally releases the heat gained in previous stages. The numerical results indicate the moisture removal is enhanced by approximately 29% utilizing SS-PCM. The effect of SS-PCM volume percentage and particularly infrared emitters are studied, as well. It is observed that SS-PCM equipped paper does not perform effectively in drying sectors where IR emitters are retrofitted. Eventually, a comparative study is performed to fairly compare the thermal performance of SL-MEPCM and SS-PCM in paper drying.