Real-time Temperature Changes Research Articles

The measurement of permeate flux based on a noninvasive method for membrane distillation: Experiment and model validation

In this paper, a new nonintrusive method of measuring permeate flux for membrane distillation is proposed, based on the law of conservation of energy. Only the surface temperatures at selected regions of a membrane are nonintrusively measured using an infrared camera and they are used to predict permeate flux. Unlike traditional methods, this new method can monitor temperature changes in real time in a nonintrusive way, and it can accurately measure the permeation flux of the membrane with a smaller error. The method is validated with a combination of experiments and computational fluid dynamics (CFD). The results of the simulation provide rich physical details including local heat and mass fluxes, local Nusselt numbers and TPC (Temperature polarization coefficient). This suggests that the permeate-side hydrodynamics play an important role in improving the heat transfer in cross-wise SGMD. The maximum error between the permeate flux measured with the new method and that of the simulation was within 9%. This method provides a guide for the precise evaluation of membrane-distillation performance exactly.

Accurate and Real-Time Temperature Monitoring during MR Imaging Guided PTT.

Photothermal therapy (PTT) is an efficient approach for cancer treatment. However, accurately monitoring the spatial distribution of photothermal transducing agents (PTAs) and mapping the real-time temperature change in tumor and peritumoral normal tissue remain a huge challenge. Here, we propose an innovative strategy to integrate T1-MRI for precisely tracking PTAs with magnetic resonance temperature imaging (MRTI) for real-time monitoring temperature change in vivo during PTT. NaBiF4: Gd@PDA@PEG nanomaterials were synthesized with favorable T1-weighted performance to target tumor and localize PTAs. The extremely weak susceptibility (1.04 × 10-6 emu g-1 Oe1-) of NaBiF4: Gd@PDA@PEG interferes with the local phase marginally, which maintains the capability of MRTI to dynamically record real-time temperature change in tumor and peritumoral normal tissue. The time resolution is 19 s per frame, and the detection precision of temperature change is approximately 0.1 K. The approach achieving PTT guided by multimode MRI holds significant potential for the clinical application.

Optic performance of single and double-glazed laminated glass in tropical climate

Validation model was generated by WINDOW 7.6 software to simulate the temperature changes of laminated glass. This approach is used as a validation model to compare the real time temperature changes observed. The parameter in the test were clear laminated glass and coloured laminated glass with using singleand double-glazed technology to assess the impact of optic glass, including U-Value, SHGC, and additional layer application of laminated Glass (Double Glazing Technology) in building temperature changes for creating thermal comfort. The results showed that single glazed technology application on clear laminated glass adjust the room temperature between 30.2°C to 31.4°C. In comparison, single colour laminated glass technology application set the room temperature 27.7°C to 28.5°C. Interestingly, the double-glazed application reduced the indoor temperature between 27.1°C to 28.5°C. These results showed that buildings’ significant thermal performance could be accomplished by applying doubleglazed technology. Nevertheless, double glazed technology was not suggested to apply in all of the skin of tropical building design due to the high-cost issues.

A New Method for Measuring Thermal Characteristics of Multistage Depressed Collectors

Multistage depressed collectors (MDCs) of traveling-wave tubes (TWTs) are used to collect kinetic power of a spent electron beam, recover part of this power to a useful electric power, and, by such a way, enhance the overall efficiency of TWTs. The heat-dissipation performance of MDCs is crucial. This brief presents a method for measuring the heat-dissipation characteristics of an MDC using an external heat source and a heat monitor. This method uses thermal transient testing techniques to measure the thermal contact resistance (TCR) of MDC. A heat source is designed to measure the characteristics of the MDC, and a SiC Schottky barrier diode is used as a heat monitor to detect the temperature changes in real time. The results show that the method is effective to measure the thermal characteristics of the MDC.

Evaluation of Rectal and Skin Temperature Variations of Anesthetised Dogs Undergoing Magnetic Resonance Imaging Diagnosis

General anesthesia produces different degrees of central nervous depression and changes in the peripheral circulation, therefore affecting the patient’s thermoregulatory mechanism. Moreover, the lack of proper, specially designed equipment for magnetic resonance imaging (MRI) environment monitoring can represent a challenge for the anesthetist. We examined the temperature variations correlated with different anesthetic protocols in dogs that underwent general anesthesia in order to evaluate changes in rectal and distal extremities temperature, before and after anesthesia. This study was conducted at the Faculty of Veterinary Medicine in Bucharest, on 21 dogs that were divided in 3 groups depending on the anesthetic protocol used. First group (B) received butorphanol (0.2 mg/kg, intravenously IV), second group (BK) had butorphanol (0.2 mg/kg) and a low dose of ketamine (2 mg/kg) IV, and group 3 (BM) was premedicated with butorphanol (0.2 mg/kg) and midazolam (0.2 mg/kg) IV. All patients were induced with propofol i.v. (3.24±0.68), intubated and maintained with isoflurane and oxygen. We determined rectal temperature before and right after the end of anesthesia with a digital thermometer and distal extremities temperature with the use of a thermal imaging camera attached to a smartphone. There was no significant difference between the rectal temperature before and after anesthesia within the 3 groups. Patients in group BK had a significant change in skin temperature at the end of anesthesia in all limbs (from 310C to 29.8 0C, p=0.008 and from 31 0C to 29.70C, p=0.009), respectively). Temperature variations were presented before and at the end of anesthesia, for all the groups especially at skin level. This study revealed that mobile thermal imaging represents a non-invasive technique that is helpful in assessing real time temperature changes in patients undergoing general anesthesia.

Diseño, construcción, verificación y prueba de un germinador de bajo costo

Los germinadores automatizados, son una herramienta indispensable para optimizar los procesos agrícolas. Sin embargo, tienen altos costos, por lo que se requiere el diseño, construcción y operación de aparatos con precios accesibles para pequeños productores. El objetivo del presente trabajo fue, diseñar, construir y verificar un prototipo de germinador de bajo costo, bajo las directrices de diseño de un prototipo. Dicho germinador, se construyó usando materiales disponibles en la región y es capaz de controlar automáticamente la temperatura y fotoperiodo mediante los circuitos W1401 y Tem-8 48386 respectivamente. Además, mediante conmutadores simples se puede controlar la intensidad lumínica. Adicionalmente, se construyó un verificador de temperatura con una tarjeta Arduino Uno. El sistema de verificación permitió el monitoreo de los cambios de temperatura en tiempo real (cada minuto). El prototipo se probó germinando semillas de Capsicum chinense, usando distintos volúmenes de agua de imbibición. De acuerdo con los resultados obtenidos, el prototipo construido se ajusta a los requerimientos recomendados tanto por la International seed testing association (ISTA), como por la Food and Agriculture Organitation (FAO) para la evaluación de semillas, pero, además mostró un rendimiento mayor, en comparación con una incubadora comercial y aun costo de construcción y operación muy menor.

Thermal infrared image processing profiles for speech anxiety monitoring

This study relates to a method for analyzing speech anxiety by processing biosignals in real time. In the previous study, the effect of galvanic skin response feedback on performance in speech anxiety was determined. The present study is a method to process the speech anxiety state in real time, and this is done by processing the facial thermal image of the presenter in real time. The root mean square waveform that tracks facial temperature changes in real time can be used as a useful indicator for diagnosing speech anxiety. The visualization of the speech anxiety profile feedback with a facial thermal image can be a better cognitive therapeutic strategy in speech anxiety education.

Intraoperative Speckle Variance Optical Coherence Tomography for Tissue Temperature Monitoring During Cutaneous Laser Therapy.

Background: Tissue temperature monitoring during cutaneous laser therapy can lead to safer and more effective treatments. In this study, we investigate the use of speckle variance optical coherence tomography (svOCT) to monitor real-time temperature changes in the excised human skin tissue sample during laser irradiation. Methods: To accomplish this, we combined the pulse laser system with a reference-based svOCT system. To calibrate the svOCT, the ex-vivo human skin samples from three individuals with tissues collected from the arm, face, and back were heated with 1-degree increments. Additionally, linear regression was used to extract and evaluate the linear relationship between the temperature and normalized speckle variance value. Experiments were conducted on excised human skin sample to monitor the temperature change during laser therapy with a svOCT system. Thermal modeling of ex-vivo human skin was used to numerically simulate the laser-tissue interaction and estimate the thermal diffusion and peak temperature of the tissue during the laser treatment. Results and Conclusion: These results showed that normalized speckle variance had a linear relationship with the tissue temperature before the onset of tissue coagulation (52°) and we were able to measure the rapid increase of the tissue temperature during laser therapy. The result of the experiment is also in good agreement with the numerical simulation result that estimated the laser-induced peak temperature and thermal relaxation time.

Experimental study on the influence of pressing force and time on thermal effect of An-pressing manipulation

To observe the influence of pressing force and time on the thermal effect of An-pressing manipulation. Eight healthy volunteers were recruited to receive An-pressing manipulation at Xinshu (BL 15) on the right side. The pressing force and time were both divided into five levels: the force described as extremely mild, mild, moderate, strong and extremely strong and time given by 2.5 min, 5.0 min, 7.5 min, 10.0 min and 15.0 min. The real-time change in local acupoint temperature as well as the change during 1.0-15.0 min after the manipulation were observed. Compared with the baseline data, the real-time changes in the temperature after An-pressing Xinshu (BL 15) on the right side with different levels of force (from mild to strong) were respectively (1.88±0.64) °C, (2.05±0.68) °C, (2.25±0.59) °C, (2.35±0.61) °C and (2.32±0.69) °C; the changes in 15.0 min after the manipulation were respectively (–0.11±0.11) °C, (0.03±0.14) °C, (0.59±0.58) °C, (1.38±0.70) °C and (2.09±0.98) °C. The real-time temperature changes after the manipulation for different durations (from short to long) were respectively (1.94±0.37) °C, (2.33±0.29) °C, (2.49±0.31) °C, (2.51±0.39) °C and (2.41±0.55) °C; the changes in 15.0 min after the manipulation were respectively (0.53±0.49) °C, (0.33±0.30) °C, (0.52±0.33) °C, (0.55±0.38) °C and (0.76±0.36) °C. The thermal effect presented an increasing tendency with the extension of pressing time, and the temperature reached the top at 7.5 min; the thermal effect showed an increasing tendency with the rise of pressing force, and the temperature reached the top upon a moderate level of force. The pressing time can produce a greater influence on the real-time temperature than the pressing force; the pressing force can produce a greater influence on maintaining the temperature than the pressing time.

Irreversible electroporation ablation area enhanced by synergistic high- and low-voltage pulses.

Irreversible electroporation (IRE) produced by a pulsed electric field can ablate tissue. In this study, we achieved an enhancement in ablation area by using a combination of short high-voltage pulses (HVPs) to create a large electroporated area and long low-voltage pulses (LVPs) to ablate the electroporated area. The experiments were conducted in potato tuber slices. Slices were ablated with an array of four pairs of parallel steel electrodes using one of the following four electric pulse protocols: HVP, LVP, synergistic HVP+LVP (SHLVP) or LVP+HVP. Our results showed that the SHLVPs more effectively necrotized tissue than either the HVPs or LVPs, even when the SHLVP dose was the same as or lower than the HVP or LVP doses. The HVP and LVP order mattered and only HVPs+LVPs (SHLVPs) treatments increased the size of the ablation zone because the HVPs created a large electroporated area that was more susceptible to the subsequent LVPs. Real-time temperature change monitoring confirmed that the tissue was non-thermally ablated by the electric pulses. Theoretical calculations of the synergistic effects of the SHLVPs on tissue ablation were performed. Our proposed SHLVP protocol provides options for tissue ablation and may be applied to optimize the current clinical IRE protocols.

Focused Ultrasound Treatment, Present and Future

The discovery that ultrasound waves could be focused inside the skull and heated to high temperatures at a focal point goes back to 1944. However, because the skull causes the ultrasound waves to attenuate and scatter, it was believed that application of this technology would be difficult, and that it would be impossible to use this approach in the surgical treatment of intracranial diseases. Eventually, magnetic resonance image guided focused ultrasound (MRgFUS) surgery began being used to treat uterine fibroids, breast cancer and bone metastasis and locally confined prostate cancer. In the first ten years of the 21st century, new developments in this technology have been achieved, broadening the scope of practical application, and treatment is now being performed in various countries around the world. In 2011, third-generation transcranial focused ultrasound made it possible to use thermocoagulation and create intracranial lesions measuring 2 to 6 mm in diameter with a precision of around 1 mm. It was also possible to produce MR images which relay information of temperature changes in real time, enabling a shift from reversible test heating to irreversible therapeutic heating. This gave rise to the possibility of a minimally-invasive treatment with outcomes similar to those of conventional brain surgery. This method is paving the way to a new future not only in functional neurosurgery, but in cranial neurosurgery targeting conditions such as epilepsy and brain tumors, among others. In this paper, we describe the current state and future outlook of magnetic resonance image guided focused ultrasound, which uses computed tomography (CT) bone images in combination with MRI monitoring of brain temperature.

Implant Drill Characteristics: Thermal and Mechanical Effects of Two-, Three-, and Four-Fluted Drills.

Avoiding excessive trauma--thermal or otherwise--during dental implant site preparation is considered critical to implant success; overheating is considered to be a major cause of bone necrosis. Studies evaluating thermal and mechanical effects of implant drill design are limited, and effects of flute design have not been accounted for. The purpose of this study was to compare heat generation and cutting efficiency associated with two-, three-, and four-fluted implant drills to investigate the optimal number of flutes. Two-, three-, and four-fluted dental implant drills with identical point, relief, and rake angles and otherwise standard dimensions were evaluated. Real-time temperature changes while drilling artificial bone were recorded using an infrared thermal imager. Cutting efficiency was assessed as the drilling time to a 15-mm depth under constant load using a specially designed recording system. Each drill variation was examined 20 times. A one-way analysis of variance was used for statistical analysis. Mean temperature increases amounted to 8.3°C, 10.8°C, and 15.1°C for two-, three-, and four-fluted drills, respectively; temperatures significantly increased (P < .001) with an increased number of flutes. Mean drilling time serving as a measure of cutting efficiency amounted to 2.6, 2.5, and 2.5 seconds for the two-, three-, and four-fluted drills, respectively. A trend of cutting efficiency increasing or decreasing according to the number of flutes was not observed. Differences in cutting efficiency among the three drill variations were statistically significant (P = .015). The cutting efficiency of the three-fluted drill was superior to that of the two-fluted drill (P = .016). Within the limitations of the study, a two-fluted drill would be preferred for osteotomy preparation due to its level of heat generation, whereas a three-fluted drill showed favorable cutting efficiency.

Preparation of Al2O3/TiO2 particle-reinforced copper through plasma spraying and friction stir processing

In this study, Al2O3/TiO2 particle-reinforced copper matrix surface composites were successfully processed via friction stir processing (FSP). A “sandwich” lap joint setup subjected to multi-pass FSP was adopted. The composite layer with a thickness of ~2200μm was achieved after triple-pass processing. The Al2O3 and TiO2 particles were evenly distributed in copper matrix and the grains were refined due to the stir and crush action of tool. The defects such as pores and interlamellar contacts in the as-sprayed layer disappeared with the particles involved into substrate. Vickers hardness test were implemented and the average hardness value achieved 448HV0.1 after triple-pass processing, which was about 4 times higher than that of the T2 copper. Shearing tensile tests were carried out and the maximum shearing force reached to 7.98kN. Real-time temperature change showed that the traveling speed has little effect on the Tm variation of stirring zone. Furthermore, the softening temperature of FSPed samples was higher than 900°C, which represents a better thermal stability.

Applying CS and WSN methods for improving efficiency of frozen and chilled aquatic products monitoring system in cold chain logistics

Wireless Sensor Network (WSN) is applied widely in food cold chain logistics. However, traditional monitoring systems require significant real-time sensor data transmission which will result in heavy data traffic and communication systems overloading, and thus reduce the data collection and transmission efficiency. This research aims to develop a temperature Monitoring System for Frozen and Chilled Aquatic Products (MS-FCAP) based on WSN integrated with Compressed Sending (CS) to improve the efficiency of MS-FCAP. Through understanding the temperature and related information requirements of frozen and chilled aquatic products cold chain logistics, this paper illustrates the design of the CS model which consists of sparse sampling and data reconstruction, and shelf-life prediction. The system was implemented and evaluated in cold chain logistics between Hainan and Beijing in China. The evaluation result suggests that MS-FCAP has a high accuracy in reconstructing temperature data under variable temperature condition as well as under constant temperature condition. The result shows that MS-FCAP is capable of recovering the sampled sensor data accurately and efficiently, reflecting the real-time temperature change in the refrigerated truck during cold chain logistics, and providing effective decision support traceability for quality and safety assurance of frozen and chilled aquatic products.

Preparation and Evaluation of Hybrid Composites of Chemical Fuel and Multi-walled Carbon Nanotubes in the Study of Thermopower Waves.

When a chemical fuel at a certain position in a hybrid composite of the fuel and a micro/nanostructured material is ignited, chemical combustion occurs along the interface between the fuel and core materials. Simultaneously, dynamic changes in thermal and chemical potentials across the micro/nanostructured materials result in concomitant electrical energy generation induced by charge transfer in the form of a high-output voltage pulse. We demonstrate the entire procedure of a thermopower wave experiment, from synthesis to evaluation. Thermal chemical vapor deposition and the wet impregnation process are respectively employed for the synthesis of a multi-walled carbon nanotube array and a hybrid composite of picric acid/sodium azide/multi-walled carbon nanotubes. The prepared hybrid composites are used to fabricate a thermopower wave generator with connecting electrodes. The combustion of the hybrid composite is initiated by laser heating or Joule-heating, and the corresponding combustion propagation, direct electrical energy generation, and real-time temperature changes are measured using a high-speed microscopy system, an oscilloscope, and an optical pyrometer, respectively. Furthermore, the crucial strategies to be adopted in the synthesis of hybrid composite and initiation of their combustion that enhance the overall thermopower wave energy transfer are proposed.

Effect of Pulsewidth on Medium Temperature Rise and Microbial Inactivation Under Pulsed Electric Field Food Treatment

In the context of developing pulsed electric field (PEF) food treatment as a potential nonthermal method in producing high-quality food products, knowledge of pulse parameters on temperature rise is important. In this research, a newly developed high-voltage square pulse generator is implemented to study the effect of pulsewidth and pulse frequency on temperature rise, keeping both the applied electric field and energy constant. Real-time temperature changes in the treatment zone during PEF treatment are measured using an infrared camera. In addition, bacterial inactivation tests are carried out to validate the functionality of the pulse generator, under the same PEF treatment conditions.

Study on the influence of the response characteristics of a temperature sensor on the measurement accuracy of a water-absorption-based high-energy laser energy meter

When using water as a cooling or absorption medium for an energy meter, a temperature sensor is limited by response characteristics and cannot reflect the real-time temperature changes in the water flow. In order to improve the accuracy of measurement, we should ensure that the corresponding value of the temperature integral will be substantially independent of the effects of the sensor response time. According to the analysis of the interaction process between temperature sensor and water flow temperature field, we have established a hot physical model of the whole measurement process, and decomposed it into a superposition of a slowly varying process and a transient process, then simplified the model. Finally, a quantitative relationship between the sensor response characteristics and measurement accuracy of the high energy laser energy meter is derived. With the mandatory heat exchange method, the frequency characteristics of the temperature field meet the requirements of the frequency characteristics of a temperature sensor; as a result, the impact on measurement accuracy is eliminated. The experimental results show that this method has good effects, and it can help to improve the measurement accuracy of a high-energy laser energy meter.

광섬유 센서를 이용한 실시간 온도 감시 시스템

본 광 분포 온도 측정 시스템은 광섬유 자체를 온도 측정용 센서로 이용하는 시스템으로, 한 가닥의 광섬유만을 포설하여 포설된 주변 전체 온도를 수 천 점으로 측정이 가능한 시스템이다. 분포 측정의 경우 측정 점의 수를 많이 할 경우 측정점당 비용을 기존 센서의 비용 수준으로 절감 할 수 있으며 동시에 한 두 가닥의 광섬유로 전체 센서를 연결 할 수 있는 장점이 있다. 본 논문에서는 일반적으로 통신용으로 사용하는 광케이블 자체를 센서 (optical sensor cable)로 활용하여 최소한 매 1m 간격으로 센서 기능을 할 수 있는 특성을 이용함으로써 각 센서와 수많은 연결선들을 줄이고 시스템은 컴퓨터를 이용하여 데이터저장, 제어나 보관 등 데이터 관리가 용이하며, 실시간 온도 변화에 따른 온도 이력정보를 이용한 실시간 온도 모니터링 시스템을 구축한다. Optical Temperature Distribution Sensor Measurement System uses fiber optic sensors itself for temperature measurement is a system which can be measured the Installed surrounding entire temperature as a thousand points by laying a single strand of fiber optic. If there are a lot of measuring points in the distribution Measurement, the cost of each measuring point can be reduced the cost level of existing sensors and at the same time this has the advantage of connecting all sensors as one or two strands of fiber. Generally Optical Fiber is used for communication but Optical Fiber itself can be used for sensor and it has the characteristic of sensor function which can be measured Temperature in the at least each one meter distance. By using these characteristics each sensor and the number of Connection Lines can be reduced. In this paper, we implement a real time temperature monitoring system, which is easy to manage and control for data storage, data management, data storage using a computer and which has the functions of monitoring and correction according to Real-time temperature changes using historical temperature data.

Effect of implant drill characteristics on heat generation in osteotomy sites: a pilot study

The objective of this study was to evaluate the effect of drill-bone contact area on bone temperature during osteotomy preparation. Conventional triflute Ø3.6 mm drills were modified with the intent to reduce frictional heat induction. The peripheral dimensions of the drill were reduced 0.15, 0.35 and 0.5 mm to evaluate the effect of surface area on induction of frictional heat between the drill and bone/cutting debris (parameter A). Also, the lateral cutting surface of the drill was set to 0.1, 2 and 7.5 mm to estimate heat induced by direct function of the drill (parameter B). A non-modified triflute drill (parameter A: 0 mm; parameter B: 15 mm) served as control. Thus, nine drills with different A/B combinations vs. one control were tested in artificial bone. Real-time temperature changes (during drilling and withdrawing) were assessed using an infrared thermal imager. Each drilling procedure was performed up to 20 times. Thermal image data were transferred to a PC for simultaneous analysis. Mean temperature changes for all modified drill combinations were smaller than for the control (P<0.001). The effects of parameters A and B were statistically significant (P<0.001). There was a significant interaction effect between the two parameters (P<0.001) showing that the effect of parameter A on the mean temperature changes is different depending on the values of parameter B. As the dimensions of parameter B decreased, the temperature change during drilling also decreased. However, a tendency for the temperature to increase or decrease by parameter A was not observed. Within the limitations of this pilot study, the observations herein suggest that reduction in contact area between the drill and bone reduces heat induction. Further studies to optimize drill/bone contact dimensions are needed.

Real Time Monitoring of Temperature Changes in Neurovascular Bundles During Robotic Radical Prostatectomy: Thermal Map for Nerve-Sparing Radical Prostatectomy

A rise in temperature of more than 55 degrees C in tissues, even for short a duration has been implicated in irreversible tissue damage. This study was aimed at recording real time temperature changes at the neurovascular bundle (NVB) during the use of cautery in robotic radical prostatectomy. The temperature was monitored with a needle electrode in 15 cases of athermal nerve sparing and 10 cases of non-nerve sparing robotic radical prostatectomy (RRP). The needle was placed in the peritoneal cavity through the camera port and inserted around the NVB. Body temperature was recorded by nasal cannula and compared with the baseline temperature at the neurovascular bundle. The distance of the needle probe from the area of cautery use, changes in temperature at the neurovascular bundle and the duration of cautery use was recorded during the use of monopolar and bipolar current in tissue dissections. The mean baseline temperature at the neurovascular bundle was 0.8 degrees C lower than the body temperature. Average duration for cautery use at the anterior bladder neck and NVB with monopolar and bipolar current was 53.6 (45-65) and 79.8 (70-92) and 56.8 (45-60) and 65.7 seconds (59-76) respectively. The mean temperature rise during bladder neck dissection (distance more than 1 cm) was 43.6 degrees C [36.4-47.3 degrees C] with the monopolar and 38.8 degrees C [36.8 degrees-42.6 degrees C] with bipolar. During NVB dissection, the mean temperature rise was 53.6 degrees C (45.1 to 68.1 degrees C) with monopolar and 60.91 degrees C (47.2 to 109.8 degrees C) with bipolar. Though this difference was not significant, the mean time to return to baseline temperature was 3 seconds more with bipolar than monopolar. Bipolar cautery may not be safer than monopolar because of a greater rise in temperature of surrounding tissues within 1 cm of its use. Further investigation is needed to fully establish the pathologic consequences associated with increased temperature due to cautery.