IR Thermal Imaging Research Articles

Preliminary study of thermal density distribution and entropy analysis during cycling exercise stress test using infrared thermography

Considerable differences related to the results of temperature changes acquired during exercise exist, and in many cases, these lead to poor correlation with physiological variables. In this preliminary study we investigated the temperature changes and the temperature distribution (entropy) of the torso during a graded cycling exercise stress test using thermal imaging and studied the correlation between the increase in pulmonary ventilation (VE) and the changes in the surface temperature of the anterior torso during exercise. Thermal images of the anterior torso were captured every 30 s during the exercise, while the resistance was gradually increased every minute until exhaustion. The thermal images were processed to obtain a mean temperature in the regions of interest (ROI) (chest, forehead, and abdomen). We also developed an algorithm to calculate the distribution of temperature and texture (entropy) within each ROI. No changes were found in absolute temperatures. However, the entropy of the chest surface area increased significantly throughout the exercise test, compared with baseline temperature at rest. This increase in entropy was significantly correlated with exercise duration and intensity (p < 0.001). Furthermore, a high correlation between the increase in VE and chest entropy during exercise was detected (r = 0.9515). No correlations were found between the increase in entropy and the abdomen or the forehead compared with the VE. The non-invasive IR thermal imaging during graded exercise, combined with advanced image processing, successfully correlates surface thermography with exercise duration and pulmonary ventilation.

Studying IR Photohyperthermia Sensitized by Titanium Nitride Nanoparticles Using Tissue-Equivalent Phantoms

Purpose: To use tissue-equivalent phantom for studies of thermal fields in biological tissues during IR photo hyperthermia with plasmonic titanium nitride nanoparticles (TiN NPs). Material and methods: Gel phantom based on polyacrylamide (PAA) with addition of naphtol green dye and intralipid 10% was created. Optical properties (reduced scattering coefficient) of phantom ingredients were determined using added absorber technique. Thermal field distribution was studied with IR thermal imaging technique. 50 nm plasmonic TiN NPs, synthetized by laser ablation in liquids, were used as sensitizers of photothermic action. Photothermal experiments were performed using two phantoms: a phantom with homogeneous optical parameters, which are relevant to biological tissues (absorption coefficient µa=0.35 сm-1, reduced scattering coefficient µ's=30 сm-1), and a phantom containing 0.02 mg/ml of TiN NPs, which increased absorption coefficient by Dµa=0.65 сm-1. The part of phantom with the NPs was located under 5 mm layer of NPs-free phantom. Photothermal effect was excited by CW laser irradiation of 830 nm wavelength and 16 W/cm2 intensity (900 mW, beam diameter: 1.3 mm) for 2 min. Thermal field distribution inside the phantom was measured by IR thermal camera. Results: A tissue-equivalent gel phantom with independently tunable absorption and scattering coefficients was designed. The phantom had cubic shape with 30 30 30 mm size. Results of photothermal experiments showed that the use of TiN NPs as sensitizers IR photohyperthermia leads to a significant increase in tissue temperature (up to 5 degrees Celsius) at distances up to 15 mm under the phantom surface. In addition, a simple experimental setup for measuring scattering coefficient of a liquid phantom ingredients was described. Conclusion: A simple method for preparation of PAA phantom for modelling photothermal heating of biological tissues and studying thermal fields distributions was described. The phantom is handy and allows one to quickly experimentally simulate the photothermal response of biological tissues, including tissues containing various spatial distributions of photosensitive NPs. TiN NPs experimentally confirmed to be an effective sensitizer of IR photothermal effect.

Novel approach for damage detection in multiscale CNT-reinforced composites via wireless Joule heating monitoring

A novel method for strain and crack propagation monitoring based on Joule heating capabilities of multiscale carbon nanotube reinforced glass fiber composites (GFRP-CNT) is reported. The manufactured GFRP-CNT composites show good Joule heating capabilities with heating rates ranging from 3 to 56 °C min−1 at applied voltages from 30 to 105 V, respectively. Multiscale GFRP-CNT composites present similar tensile strength and Young's Modulus than conventional GFRP but very enhanced failure strain due to the toughening effect of CNTs. The wireless monitoring via Joule heating shows a very high sensitivity and strain resolution (with values ranging from 0.01 to 0.1%) for early crack initiation and subsequent propagation. Finally, the thermal IR imaging also allows to create a complete mapping of the health of the structure during the whole test, allowing the detection, localization and quantification of early damage and, thus, proving an outstanding potential for Structural Health Monitoring (SHM) applications in comparison to other conventional techniques.

Investigation of the Temperature Sensitivity of 20-Years Old Field-Aged Photovoltaic Panels Affected by Potential Induced Degradation

One effect of moisture ingress on solar panels is potential induced degradation (PID). Solar panels affected by PID experience large leakage currents between the solar cells and the module’s frame, which leads to substantial power degradation. In the present work, the temperature coefficients of 3 old PV panels affected by PID were investigated. In the electroluminescence images, solar cells nearer to the edge of the modules appear darker due to ohmic shunting. IR thermal images acquired under clear sky outdoor conditions show that the majority of the warmer cells (hotspots) were located closer to the edge of the modules. The difference in cell temperature (∆T) due to PID effect ranges from 7 °C to 15 °C for the 3 field-aged modules. The average temperature coefficient of efficiency (βηm) was found to be −0.5%/°C. Also, it was observed that the temperature coefficients of open circuit voltage (βVoc = −0.4%/°C), maximum power point voltage (βVmpp = −0.5%/°C), and fill factor (βFF = −0.2%/°C), were the underlying factors for the degradation in the Pmax of the old solar panels affected by PID. This accounted for an average 1.2%/year overall degradation in the efficiency of these modules. Most notably, it was discovered that the PV modules affected by PID show negative temperature coefficients of maximum power point current (βJmpp) due to large leakage currents. This observed negative βJmpp we believe is characteristic of PV panels affected by PID.

Identification of Drunk People Among Crowds Using Thermography and Machine Learning

This paper attempts to present a novel and safe, non-contact method to classify drunk and sober people, unlike the conventional techniques. For example, using a Breathalyzer can increase the chances of infection. The image classification is programmed based on two differently trained machine learning models, whose results are compared and their accuracy predicted. Using thermal IR images helps identify the thermal behaviour of the facial features, mainly around the eyes, which, according to studies, widely increases when intoxicated with alcohol.

Influence of synthetic air jet temperature on local heat transfer characteristics of synthetic air jet impingement

The influence of synthetic air jet temperature on local heat transfer distribution of a synthetic air jet impinging on a smooth flat surface is investigated experimentally. The actuator frequency (f = 100 Hz to 300 Hz) and jet to orifice spacing (z/d = 1 to 8) is considered for the present study. The local heat transfer study is obtained using thin foil and IR thermal imaging technique. At z/d = 1, the Nusselt number characteristics are found approximately 2 times greater when synthetic air jet temperature is considered as jet air temperature instead of surrounding air temperature for all the frequencies. The experimental results observed that heat transfer distribution is strongly influenced by synthetic air jet temperature especially at lower orifice to jet distance.

A Simple Algorithm Based on a 2D Heat Diffusion Mathematical Model to Extract a Surface Crack Length from a Sonic IR Thermal Image Alone

A Simple Algorithm Based on a 2D Heat Diffusion Mathematical Model to Extract a Surface Crack Length from a Sonic IR Thermal Image Alone

Importance of Image Enhancement and CDF for Fault Assessment of Photovoltaic Module Using IR Thermal Image

Infrared thermography is the science of measuring the infrared energy emitted by an object, translating it to apparent temperature variance, and displaying the result as an infrared image. Significantly, acquiring thermal images delivers distinctive levels of temperature differences in solar panels that correspond to their health status, which is beneficial for the early detection of defects. The proposed algorithm aims to analyze the thermal solar panel images. The acquired thermal solar panel images were segmented into solar cell sizes to provide more detailed information by region or cell area instead of the entire solar panel. This paper uses both the image histogram information and its corresponding cumulative distribution function (CDF), useful for image analysis. The acquired thermal solar panel images are enhanced using grayscale, histogram equalization, and adaptive histogram equalization to represent a domain that is easier to analyze. The experimental results reveal that the extraction results of thermal images provide better histogram and CDF features. Furthermore, the proposed scheme includes the convolutional neural network (CNN) for classifying the enhanced images, which shows that a 97% accuracy of classification was achieved. The proposed scheme could promote different thermal image applications—for example, non-physical visual recognition and fault detection analysis.

Electronic and thermal transfer actuating memory catalysis for organic removal by a plasmonic photocatalyst

To take full advantage of solar energy, a memory-catalyst Ag/BiOCl/Ti3C2 was fabricated using a two-step precipitation method, which performed well in the degradation of tetracycline hydrochloride (TC) in the light and dark. The generation of reactive oxygen species in the light and dark were both certified. Furthermore, quenching experiments and quantum lifetime measurements demonstrated the excited-electron transfer process, and these tests confirmed the electron (e−) transformation resulting from the localized surface plasmon resonance effect (LSPR) in two-electron donors, Ag NPs and Ti3C2.Further, the calculation using COMSOL software suggested the enhancement of the electric field through modification of the two co-catalysts mentioned above. Because of this enhancement, the activated e− might be further reacted in the dark for the memory-catalysis process. On the other hand, based on the result of IR thermal imaging, the thermal transmission for formation using LSPR might be another factor in promoting memory catalysis as an energy resource. This work demonstrates for the first time that LSPR might actuate memorycatalysis using e− transmission and energy input, and the results shed light on the design and comprehension of memory photocatalysis for its practical use in pollutant removal and other fields.

Stimulation of Myofascial Trigger Points in the Sternocleidomastoid Evokes Facial Thermal Response Correlated with the Referred Pain

The purpose of this research is to identify and correlate the referred pain evocated by myofascial trigger points (TrPs) pressure pain threshold (PPT) in the sternocleidomastoid muscle using thermal infrared imaging (IR). Facial IR images of 46 volunteers (21 male and 25 female, average age 32 ± 6.3) undergoing PPT of five TrPs locations on the sternocleidomastoid belly were recorded. Each PPT lasted 10 s, with an interstimulus interval of 2 min. Sixteen thermal IR images were recorded for each subject: at baseline (t0), 2 s before PPT (t1), 2 s (t2) and 60 s (t3) after PPT of each TrPs location. During the interstimulus interval, subjects were asked to draw over a head–neck template displayed on a computer screen the areas of referred pain eventually evoked by the stimulation and the referred pain intensity by means of a Visual Analogue Scale (VAS). The VAS template was then superimposed with the IR records. Two temperature (T) variations were calculated: ΔT1 = T(t2) − T(t1) and ΔT2 = T(t3) − T(t1). Differences in ∆T range ≥ 0.2 °C have been considered significant. In 77% of the superimpositions, the referred pain area corresponded to a ΔT2 ≥ 0.2 °C while only the 59% corresponded to a ΔT1 ≥ 0.2 °C. In 19% of superimpositions, a ΔT2 ≥ 0.2 °C did not correspond to a referred pain area indicated by the patient, and this percentage lowers to 4% for ΔT1 ≥ 0.2 °C. None of the areas that reported a VAS of 0 or 1 showed a ΔT1 ≥ 0.2 °C or a ΔT2 ≥ 0.2 °C. Considering the limitations of this pilot study, IR could be used to identify referred pain evocated by TrPs on sternocleidomastoid muscle.

Local heat transfer characteristics of synthetic air jet impinging on a smooth convex surface

The local heat transfer characteristic of synthetic air jet impinging on convex surface is studied experimentally. The heat flux on the convex surface is maintained constant. The experiment is carried out for different actuator frequency (f = 100 Hz–300 Hz), jet to plate distance (z/d = 1 to 8) keeping the orifice diameter constant. The local heat transfer characteristic of synthetic air jet on the convex surface is obtained by IR thermal imager using thin foil technique. Local heat transfer characteristics is studied in terms of local Nusselt number along the axial (x/d at r = 0) and radial direction (r/d at x = 0) of convex surface. The obtained result shows that the local heat transfer is strongly influenced by actuator frequency and jet to plate distance. The actuator frequency (f = 200 Hz) and lower jet to plate distance (z/d = 2) is observed effective at all jet to plate distance and actuator frequency. The correlation of maximum local Nusselt number in terms of Reynolds number is obtained with the maximum deviation of 18%. The maximum uncertainty in measurement of average Nusselt number is observed less than ±6%.

Ultralow Power Sensor Package for Early Warning of Wildland Fires

Introduction: The wildfires in California and throughout the western USA have been devastating, especially over the past 3 years, causing loss of lives, incredible property losses, and the bankruptcy of a giant utility [Pacific Gas and Electric] with over $50B of debt. And it is not just the USA that suffers from such fiery disasters but there are devastating fires throughout Australia, Siberia, and around the world. The premise is that early detection could provide avenues for emergency response and the limitation of lost lives and property damage. Current methods to detect these fires ranges from deployment of local forest rangers, satellite optical and thermal IR imaging, some local monitoring, and public education. But none of these are adequate as satellites may not have resolution required for small startup fires and can be obscured by weather. Since fires produce emissions that can provide an atmospheric signature including gases and particles as well as thermal plumes, the hypothesis is that detection of these “fire” signatures with sensitivity could provide early warning if a low-cost distributed network of sensors is deployed.The case can be made for sensing atmospheric emissions in that Carbon Monoxide is produced in high concentrations especially in smoldering fires and has been used for early warning of fires in coal mines for half a century or more. Figure 1 illustrates the use of CO to map the impact of 2018 fires in California through IR imaging through 18000 feet of the atmosphere1 at 200 ppb and lower concentrations. Clearly CO is related to the fire activity but how early can a fire be sensed? What confounding variables will be present such as T, P, RH, and wind velocity or local activities and the natural variability of the chemical composition of the air at low levels? Are CO or particles the best emission parameters to monitor or are better variables available? The answers to these questions are key to the design and deployment of an early warning system based on measurement of atmospheric conditions and atmospheric fire signature emissions! Methods The approach has two objectives in this early research: 1] to understand the emission signatures from fires as recorded by low cost environmental sensors, and 2] to evaluate the feasibility of a practical early warning fire detector based on emission signatures in addition to changes in T, RH, and wind direction. Clearly, we know CO2 (~1500g/kg forest fuel) and CO (~100g/kg) are the largest gaseous emissions by >2 orders of magnitude, but other variables include particles (~20-50g/kg), as well as gases hazardous at very low concentrations like O3, NO2, SO2 and other gases such as methane, CH2O and other NMVOCs2 that could come from different sources.A monitoring system was designed made from low cost COTS [commercially off the shelf] sensors and electronics that could be used to gather field data. The system is complete with sensor hardware, communication alternatives, and computation capability. SPEC sensors3 and KWJ4 electronic hardware and algorithms were selected to partner with commercial CO2, particulate and environmental [T, P, RH] sensors5 in order to build a system that could address Objective 1. Evaluation of actual field data will then be used to achieve Objective 2 as it is clear that a deployed sensor system must have low cost, near zero power, and long-term stability as well as be free from interfering signals. Results The construction of the prototype integrated monitoring and analysis system node [at left] was completed and included SPEC Sensors for CO, NO2, O3; Alphasense SO2 sensor, Sensirion SPD30 (NDIR) CO2 and SPS30 particulate sensor as well as Wind Speed and Direction, a 4.4 A∙h LiPo Battery, two 3.4 W adjustable solar panels, and USB Connection for power/communications.Data from a deployed SPEC printed CO sensor - taken by a third party (SCAQMD) - is illustrated at right. The SPEC CO sensor was only calibrated once at the start of the deployment and the data from it are plotted vs a co-located EPA reference instrument. The agreement over months supports the hypothesis that an ultra-low-cost screen-printed electrochemical sensor can possess the stability that will be needed in a practical application scenario. There is significant agreement over 0-2000ppb between a frequently calibrated instrument with 100 ppb resolution reading 1/hr and the hourly average of a tiny low-cost real-time sensor! Concluding Remarks: The systems and sensor and the application data will be discussed further in the presentation. The data supports the possibilities for complete systems and remote nodes that can both detect wildfires and then better understand wildfire emissions. Early fire warnings though emission monitoring will become one of the methods contributing to the protection of lives, property and health. Study of the application and improving sensor systems is ongoing.

A Case Study on Assessment Performance and Energy Efficient Recommendations for Industrial Boiler

As India is a developing country, industrialization is increasing day by day and there is a great need for industry energy audit. Audit helps to maintain and save energy from being wasted and helps in achieving highest efficiency of industrial equipment. This paper contains an actual industry audit report on boiler performance. This paper contains a report on Thermal analysis of boilers, thermal skin heat loss of boilers, O2 percentage control in flue gases to standard values, effect of coal additive, etc. This paper also contains a report on waste heat recovery options for thermal boiler, flue efficiency monitor, infrared thermometer, ultrasonic peak detector IR thermal imager. These equipment are used for energy assessment of boilers. Thermography survey of boiler surface is carried out to estimate the radiation and the other losses and the result of this total annual saving after insulation repairing or maintenance is Rs.8.48 lakh and investment is around Rs.6.31 lakh. Economizer performance of both the ISGEC and Thermax boiler can be improved with the help of suggested measures. It will help to save approximately rupees Rs.38.42 Lakh annually and investment on maintenance cost is negligible. In short, this paper deals with assessment of all boilers, evaluates their efficiencies and losses to identify energy saving opportunities and presents them in a report with their payback periods. Keywords: Energy, Energy audit, assessment, boiler.

Plasmonic Layer as a Localized Temperature Control Element for Surface Plasmonic Resonance-Based Sensors.

Surface plasmon resonance (SPR) sensing is a well-established high-sensitivity, label-free and real-time detection technique for biomolecular interaction study. Its primary working principle consists of the measurement of the optical refractive index of the medium that is in close vicinity of the sensor surface. Bio-functionalization techniques allow biomolecular events to be located in such a way. Since optical refractive indices of any medium varies with the temperature, the place where the measurement takes place shall be within a temperature-controlled environment in order to ensure any temperature fluctuation is interpreted as a biomolecular event. Since the SPR measurement probes the sensed medium within the penetration depth of the plasmonic wave, which is less or in the order of 1 µm, we propose to use the metallic film constituting the detection surface as a localized heater aiming at controlling finely and quickly the temperature of the sensed medium. The Joule heating principle is then used and the modeling of the heater is reported as well as its validation by thermal IR imaging. Using water as a demonstration medium, SPR measurement results at different temperatures are successfully compared to the theoretical optical refractive index of water versus temperature.

Deep Learning Thermal Image Translation for Night Vision Perception

Context enhancement is critical for the environmental perception in night vision applications, especially for the dark night situation without sufficient illumination. In this article, we propose a thermal image translation method, which can translate thermal/infrared (IR) images into color visible (VI) images, called IR2VI. The IR2VI consists of two cascaded steps: translation from nighttime thermal IR images to gray-scale visible images (GVI), which is called IR-GVI; and the translation from GVI to color visible images (CVI), which is known as GVI-CVI in this article. For the first step, we develop the Texture-Net, a novel unsupervised image translation neural network based on generative adversarial networks. Texture-Net can learn the intrinsic characteristics from the GVI and integrate them into the IR image. In comparison with the state-of-the-art unsupervised image translation methods, the proposed Texture-Net is able to address some common challenges, e.g., incorrect mapping and lack of fine details, with a structure connection module and a region-of-interest focal loss. For the second step, we investigated the state-of-the-art gray-scale image colorization methods and integrate the deep convolutional neural network into the IR2VI framework. The results of the comprehensive evaluation experiments demonstrate the effectiveness of the proposed IR2VI image translation method. This solution will contribute to the environmental perception and understanding in varied night vision applications.

Investigation of gas heating effect and induced pressure waves of a single microdischarge in atmospheric pressure dielectric barrier discharges

This work investigates the gas heating process of a single microdischarge (MD) and the evolution of flow dynamics due to the induced pressure waves by using the transient 3D gas flow model of a single MD (GFM-MD) with the calculated heating sources validated. The heating sources of different heating mechanisms are calculated by the 1.5D plasma fluid model with the framework of air chemistry and provided as the source term of the energy equation solved in the steady-state 3D GFM-Reactor for obtaining the temperature distribution of the reactor to validate the overall heating source by comparing with experimental measurements. The validated heating sources in different temporal phases are provided as the volumetric heating sources in the sheath and bulk regions in the transient 3D GFM-MD to model the gas heating process and evolution of flow dynamics. The simulated power consumption of a single MD is around 0.068 W which is close to the average measured power consumption of a single MD as around 0.053 W. The average gas temperature in the central region of the reactive zone is around 440 K which agrees with the rotational temperature determined as 460 K. The maximum simulated surface temperature reaches 414 K which is in good agreement with that measured by the IR thermal imager as 435 K. The spatial average heating source increases dramatically to the level of 1011 W m−3 in a few ns during the breakdown (BD) phase from the low heating source of 107 W m−3 in the pre-BD. Detailed analysis shows that the kinetics and ionic Joule heating are dominant heating sources with comparable contributions. The heating source of the kinetics reaches the level of 1011 W m−3 across the gap with a moderate increase near the sheath region, while the heating source of the ionic Joule heating remains at a low level across the gap with a dramatic increase to the level of 1013 W m−3 in the sheath region in the BD phase, resulting in the rapid increase of gas temperature from 390 K to 550 K in the sheath region in a few ns. The dramatic increase of the ionic Joule heating in the sheath region in the BD phase results in the rapid increase of pressure to the level of around 1060 torr. An induced high-pressure wave is formed and moves from the sheath region to ambient air with the wave speed estimated as 410 m s−1 which is close to the speed of sound as observed experimentally. The high-pressure region results in a significant pressure gradient between the sheath region and ambient air in the gap, leading to an increase of the flow velocity. As air moves rapidly outward from the sheath region, the density in the sheath region decreases. The low-density zone in the sheath region results in the formation of a low-pressure wave after the induced high-pressure wave. The pressure waves move outward continuously, leading to the evolution of flow dynamics.

Dynamic characterization of indocyanine green-assisted dental caries ablation with continuous diode laser using thermal imaging and fluorescence spectroscopy.

We describe the time-resolved thermal changes in indocyanine green (ICG)-assisted diode laser ablation of dental caries as a potential technique for painless treatment based on the selective photoabsorption and controlled photothermal ablation. Static ablation mode produced a higher temperature rise compared with scanning mode due to localized accumulation of heat. A temperature rise between 45-80 and 70-95°C was obtained after 20s that corresponded to 29 and 80Wcm-2, respectively. The temperature of the tooth surface increased by irradiation time, and it behaved linearly up to 70°C at 29 and 80Wcm-2. A maximum ablation per area of about 0.3 and 0.45mgcm-2 was achieved after 80s exposure at 29 and 80Wcm-2, respectively. A statistically significant difference is observed in mean carious teeth weight at various exposure times between low and high irradiances. A thermal penetration depth of 0.8-9mm is determined for 1-100s of exposure time. The IR thermal imaging of ICG temperature as a function of exposure time showed a linear increase for 60s beyond which it deviated. The laser-induced fluorescence spectroscopy indicated that the ICG quality can be altered during the course of irradiation, which in our case, it corresponded to ≈ 78% loss of signal within 23min of exposure. The caries removal experiment was performed within 100s corresponding to ≈ 7% loss. We believe that the application of the above-combined technique can be utilized as a monitoring device to control the ablation interaction process.

Free space super focusing using all dielectric hyperbolic metamaterial

Despite that Hyperbolic Metamaterial (HMM) has demonstrated sub-wavelength focusing inside of it, sub-wavelength imaging in free space of HMM is rarely introduced. The decay of hyperbolic momentum space outside the hyperbolic medium has hindered the realization of sub-wavelengh focusing in the near field of HMM. Furthermore, manipulating the negatively refracted waves exiting the HMM have addressed another major obstacle to realize free space sub-wavelength focusing. In this work, we report extended sub-wavelength focusing in free space based on negative refraction of light exiting the HMM. The proposed structure is composed of multilayers of doped InAs/intrinsic InAs integrated with metallic slit. We theoretically simulate the doped InAs/intrinsic InAs HMM and investigate the negative refraction behavior outside the HMM. We optimized the structure for achieving high resolution down to 0.2λ, extended to a distance of 3.2 µm in free space. Also, sub-wavelength focusing in free space has been studied at different doping concentrations showing that the small doping concentrations exhibit enhancement in resolution at short distances up to 600 nm away from the HMM. Extending the focusing distance is achieved up to distance 3.5 µm from the hyperbolic structure by manipulating the doping concentration. This proposed lens configuration is expected to find potential usage in mid IR thermal imaging and photolithography application.

Alkyl-grafted azobenzene molecules for photo-induced heat storage and release via integration function of phase change and photoisomerization

Azobenzene (azo) has attracted tremendous attention on solar thermal fuels on account of controllable energy storage and release. However, it remains great challenge to realize the light-induced rapid heat output due to the limited structure transformation. Herein, we synthesized two kinds of azo compounds (T-Azo, F-Azo) with different alkyl chains. The compounds combine multiple functions, reversible phase (solid-to-liquid) transition and trans-cis isomerization, to realize optically controllable heat release at room temperature. Compared with the F-Azo (8.2 °C), the relatively short-chain T-Azo obviously decreases to −6.3 °C in crystallization temperature after trans-to-cis isomerization due to weak molecular interaction. The F-Azo releases photo-thermal energy and phase-change enthalpy reaching a high energy density of 198.4 J g−1, which is 16% higher than that of T-Azo (170.5 J g−1). The IR thermal imaging camera shows that the temperature difference of F-Azo attains 2.1 °C at room temperature (25 °C) under the illumination of blue light (420 nm). This work puts an insightful understanding of controlling photo-thermal energy by phase change and photoisomerization.

Saha Şartlarında Aerobik Stabilite Süresince Mikrobiyal Kompozisyondaki Değişikliklerin Termal Kamera Görüntüleme Tekniği ile Değerlendirilmesi

Amaç: Araştırmanın ana amacı; Termal Kamera Görüntüleme Tekniğinin, silajdaki aerobik dönemde meydana gelen bozulmanın boyutları hakkında güvenilir ve pratik bir ölçü aracı olarak kullanılıp kullanılamayacağını tespit etmektir. Materyal ve Metot: Araştırma Tekirdağ ilinde mısır silajı yapan bir işletmede yürütülmüştür. Bu amaçla toprak üstü silonun yüzey alanı (sağ, orta ve sol bölge) olmak üzere 3 örnekleme bölgesine ayrılmıştır. Her bir bölgedeki sıcaklık değerleri ve ortam sıcaklığı 40 gün süreyle sıcaklık sensörleri ile ölçülüp kaydedilmiştir. Araştırmanın 0., 7., 14., 21. 30. ve 40. günlerinde silonun belirlenen 3 farklı noktasından 5 tekerrür olmak üzere alınan silaj örneklerinde kimyasal ve mikrobiyolojik parametrelere ilişkin analizler yürütülmüştür. Aynı zamanda, Fluke Ti9 IR (160x120) marka termal kamera ile 1 m mesafeden silo yüzeyinin belirlenen bölgelerinden görüntüleme yapılarak değerlendirme sonuçları kaydedilmiştir. Daha sonra elde edilen veriler SmartView®software programında değerlendirilmiştir. Bulgular: Araştırma sonucunda, termal kamera görüntüleme tekniği ve sıcaklık sensörlerine ilişkin değerlerin paralellik gösterdiği tespit edilmiştir. Sonuç: Termal kameranın, aerobik stabilitenin erken döneminde bozulmanın boyutlarını belirleyebilmek ve silaj amenajmanını geliştirmek amacı ile saha şartlarında pratik bir yöntem olarak kullanılabileceği sonucuna varılmıştır.