Temperature Compensation Mechanism Research Articles

A Temperature-Robust Envelope Detector Receiving OOK-Modulated Signals for Low-Power Applications

This paper presents a passive Envelope Detector (ED) to be used for reception of OOK-modulated signals, such as in Wake-Up Receivers employed within Wireless Sensor Networks, widely used in the IoT. The main goal is implementing a temperature compensation mechanism in order to keep the passive ED input resistance roughly constant over temperature, making it a constant load for the preceding matching network and ultimately keeping the overall receiving chain sensitivity constant over temperature. The proposed ED was designed using STMicroelectronics 90 nm CMOS technology to receive 1 kbps OOK-modulated packets with a 433 MHz carrier frequency and a 0.6 V supply. The use of a block featuring a Proportional-to-Absolute Temperature (PTAT) current yields a 5 dB reduction in sensitivity temperature variation across the −40 °C to 120 °C range. Moreover, two different implementations were compared, one targeting minimal mismatch and the other one targeting minimal area. The minimal area version appears to be better in terms of estimated overall chain sensitivity at all temperatures despite a higher sensitivity spread.

Improving the quality of resistance welded thermoplastic composite joints by applying ultrasonic

Resistance welding, a favored method for joining thermoplastic composites, often faces the challenge of nonuniform bonding which leads to weak bonding at the overlap edge and compromises joint integrity. This study proposes a novel modification to traditional resistance welding by incorporating ultrasonic during the final stage of the process. We employed various durations of resistance welding and ultrasonic to join the GF/PPS composites, which yielded significant improvements in bonding strength and welding efficiency. Applying ultrasonic introduced a self-adaptive temperature compensation mechanism, enhancing the temperature at the overlap edge while diminishing the temperature difference between the center and edge of the overlap. This method also improved fusion bonding by encouraging resin flow along the unfused interface at the overlap edge, thereby expanding the bonding area. Notably, the introduction of ultrasonic revealed a new bonding mechanism involving the interaction between molten PPS and unmelted PPS, which was thoroughly examined. The results revealed a 19% increase in lap shear strength and a 40% reduction in welding time for joints with ultrasonic compared to those without ultrasonic.

Temperature compensation and entrainment in cyanobacteria circadian rhythm

ABSTRACT Circadian rhythm is an endogenous rhythmic behavior of organisms used to adapt to the external environment. Although most biochemical reactions accelerate with increasing temperature, the period of circadian rhythms remains relatively stable across a range of temperature, a phenomenon known as temperature compensation. Meanwhile, circadian rhythms can be reset by environmental signals, such as daily periodic light or temperature, a phenomenon known as entrainment. Cyanobacteria are the simplest organisms to have circadian rhythms. The effect of light on cyanobacteria circadian rhythm has been widely studied with mathematical models. However, the effect of temperature on cyanobacteria circadian rhythm and the mechanisms of temperature compensation and entrainment are far from clear. In this paper, we apply a recent model to incorporate temperature dependence by Van’t Hoff rule. With numerical simulation, we study the temperature compensation and entrainment in detail. The results show that the system can exhibit temperature compensation when the post-transcription process is insensitive to temperature. The temperature compensation is caused by the cancellation of the increase of amplitude and the acceleration of speed, resulting in the stable period, when the temperature rises. The system can also exhibit temperature entrainment in constant light in a very limited temperature range. When the periodic light is added simultaneously to simulate more realistic environment, the temperature range of entrainment is greatly improved. The results also suggest that long-day condition is conducive to entrainment. The findings of this paper provide a theoretical reference for biological research and help us understand the dynamical mechanisms of cyanobacteria circadian rhythm.

Nutritional compensation of the circadian clock is a conserved process influenced by gene expression regulation and mRNA stability.

Compensation is a defining principle of a true circadian clock, where its approximately 24-hour period length is relatively unchanged across environmental conditions. Known compensation effectors directly regulate core clock factors to buffer the oscillator's period length from variables in the environment. Temperature Compensation mechanisms have been experimentally addressed across circadian model systems, but much less is known about the related process of Nutritional Compensation, where circadian period length is maintained across physiologically relevant nutrient levels. Using the filamentous fungus Neurospora crassa, we performed a genetic screen under glucose and amino acid starvation conditions to identify new regulators of Nutritional Compensation. Our screen uncovered 16 novel mutants, and together with 4 mutants characterized in prior work, a model emerges where Nutritional Compensation of the fungal clock is achieved at the levels of transcription, chromatin regulation, and mRNA stability. However, eukaryotic circadian Nutritional Compensation is completely unstudied outside of Neurospora. To test for conservation in cultured human cells, we selected top hits from our fungal genetic screen, performed siRNA knockdown experiments of the mammalian orthologs, and characterized the cell lines with respect to compensation. We find that the wild-type mammalian clock is also compensated across a large range of external glucose concentrations, as observed in Neurospora, and that knocking down the mammalian orthologs of the Neurospora compensation-associated genes CPSF6 or SETD2 in human cells also results in nutrient-dependent period length changes. We conclude that, like Temperature Compensation, Nutritional Compensation is a conserved circadian process in fungal and mammalian clocks and that it may share common molecular determinants.

Artificial temperature-compensated biological clock using temperature-sensitive Belousov–Zhabotinsky gels

The circadian rhythm is a fundamental physiological function for a wide range of organisms. The molecular machinery for generating rhythms has been elucidated over the last few decades. Nevertheless, the mechanism for temperature compensation of the oscillation period, which is a prominent property of the circadian rhythm, is still controversial. In this study, we propose a new mechanism through a chemically synthetic approach (i.e., we realized temperature compensation by the Belousov–Zhabotinsky (BZ) gels). The BZ gels are prepared by embedding a metal catalyst of the BZ reaction into the gel polymer. We made the body of BZ gels using a temperature-sensitive polymer gel, which enabled temperature compensation of the oscillation by using temperature dependence of volume. Moreover, we constructed a simple mathematical model for the BZ oscillation in temperature-sensitive gels. The model can reproduce temperature compensation of BZ gels, even though all reactions are temperature sensitive according to the Arrhenius rule. Our finding hints that a soft body coupling may be underlying temperature-compensated biological functions, including circadian rhythms.

Variations in Circadian Clock Organization & Function: A Journey from Ancient to Recent.

Circadian clock components exhibit structural variations in different plant systems, and functional variations during various abiotic stresses. These variations bear relevance for plant fitness and could be important evolutionarily. All organisms on earth have the innate ability to measure time as diurnal rhythms that occur due to the earth's rotations in a 24-h cycle. Circadian oscillations arising from the circadian clock abide by its fundamental properties of periodicity, entrainment, temperature compensation, and oscillator mechanism, which is central to its function. Despite the fact that a myriad of research in Arabidopsis thaliana illuminated many detailed aspects of the circadian clock, many more variations in clock components' organizations and functions remain to get deciphered. These variations are crucial for sustainability and adaptation in different plant systems in the varied environmental conditions in which they grow. Together with these variations, circadian clock functions differ drastically even during various abiotic and biotic stress conditions. The present review discusses variations in the organization of clock components and their role in different plant systems and abiotic stresses. We briefly introduce the clock components, entrainment, and rhythmicity, followed by the variants of the circadian clock in different plant types, starting from lower non-flowering plants, marine plants, dicots to the monocot crop plants. Furthermore, we discuss the interaction of the circadian clock with components of various abiotic stress pathways, such as temperature, light, water stress, salinity, and nutrient deficiency with implications for the reprogramming during these stresses. We also update on recent advances in clock regulations due to post-transcriptional, post-translation, non-coding, and micro-RNAs. Finally, we end this review by summarizing the points of applicability, a remark on the future perspectives, and the experiments that could clear major enigmas in this area of research.

A Programmable Multiple Frequencies Clock Generator With Process and Temperature Compensation Circuit for System on Chip Design

This article presents a programmable multiple frequencies clock generator with a process and temperature compensation circuit design. The proposed clock generator can achieve a stable and wide frequency range output for a single input frequency by using digital control codes as well as process and temperature compensation mechanisms. In our approach, the first step is to adjust the duty-cycle of the input clock by using a digitally controlled pulsewidth modulator (DCPWM) to generate an output clock signal with a duty-cycle of 20% to 80%. Second, the various duty-cycle clock outputs of the DCPWM are integrated by the duty-cycle-to-voltage converter to generate analog voltage signals to control the succeeding voltage-controlled ring oscillator (VCO). Through the use of various control voltages, different VCO output frequencies are generated. Finally, by using the process and temperature compensation circuit, the proposed clock generator can provide a stable and wide frequency range. The proposed chip is fabricated in a 180-nm CMOS process and has an output frequency range of 35–138 MHz at a supply voltage of 0.9 V. At 120 MHz, the power dissipation and rms jitter are 224.3 μW and 7.84 ps, respectively. The active area of the chip is 0.62 mm × 0.76 mm.

Utilizing the Intrinsic Mode of Weakly Coupled Resonators for Temperature Compensation.

Accelerometers based on outputting amplitude ratios in weakly coupled resonators (WCRs) are attractive because their parametric sensitivity is higher by two or three orders of magnitudes than those based on outputting frequency. However, the impact of temperature on the coupler is a key factor in accelerometer applications. This paper proposed a novel mode-localized WCR accelerometer with a temperature compensation mechanism, with sensitive elements incorporating a double-ended tuning fork (DETF) resonator, clamped–clamped (CC) resonator, and a micro-lever coupler. The DETF out-of-phase mode is utilized, which is only sensitive to temperature, to measure the temperature change of WCRs and complete the temperature compensation using the compensation algorithm. This proposed method has no time delay in measuring the temperature of sensitive elements and no temperature difference caused by the uneven temperature field. The parametric sensitivity in amplitude ratio (AR) to acceleration drifting with temperature was theoretically analyzed, and the novel device was designed and fabricated by a silicon-on-glass process. Both simulation and experiment results demonstrated that the coupling stiffness drifted with temperature, which resulted in the drifts of its sensitivity to acceleration and zero-bias stability. Using the intrinsic mode of WCRs, in terms of the DETF out-of-phase mode, as an in situ thermometer and carrying out the temperature compensation algorithm, the drift of zero bias could be suppressed from 102 mg to 4.5 mg (g is the gravity acceleration), and the drift of the parameter sensitivity in AR was suppressed from 0.74 AR/g to 0.02 AR/g with the temperature range from 330 K to 370 K and acceleration range from 0 g to 0.2 g.

Development of the X-Perce—A Universal FBG-Based Force Sensing Kit for Laparoscopic Surgical Robot

For surgical robot, an independent contact sensing system can always provide intuitive operation reference in parallel to non-contact information. As one of them, force sensing system developed based on fiber Bragg grating sensor (FBGs) has been at the forefront of gaining force information from surgical device in the past decade. Application span from vitrectomy, cerebral surgery to cardiac ablation yet still rarely seen in laparoscopic surgery. In this paper, we present the development of the X-Perce—a force sensing kit that can be universally deployed on the laparoscopic surgical robot. By the design of a 3D-printed biocompatible joint combining with six FBGs layout, the proposed kit is able to perform tri-axial force sensing with temperature compensation and dual-thread mechanism. Modular design and standardized integration process are able to reduce the cost of manufacture, which allow the X-Perce to be consumable and commercial. Optimization based on mechanical modelling is implemented to enhance the system performance. Testing and evaluation is conducted to assess the resolution, static indexes and tracking performance of the prototype. Overall, we provide here a mechanical force sensing solution for the instrument that can be integrated on the Da-Vinci-like laparoscopic robotic system, along with a complete design paradigm for FBG sensing system alike.

Effects of temperature on muscle growth and collagen deposition in zebrafish (Danio rerio)

Collagen is a major extracellular matrix component playing pivotal roles in maintaining the muscle growth and flesh texture of fish. Enhancement of collagen deposition in muscle by environmental factors serves as an effective way to improve quality of fish products. However, as a critical environmental factor in aquaculture, the effects of temperature on muscle growth and collagen metabolism in fish are largely unknown. Here, we used zebrafish (Danio rerio) as a fish model to investigate the effects of water temperature (18 ℃, 28 ℃, 34 ℃) on the growth performance, muscle structure and collagen metabolism. After the 7-week trial, the growth performance and density of muscle fiber were significantly reduced in 18 ℃ and 34 ℃ groups, compared to the control group (28 ℃). While, the collagen deposition in muscle was significantly enhanced in low temperature group (18 ℃). RNA-sequencing and qRT-PCR indicated that the transcription of collagen genes (col1a1a, col1a1b, col2a1b, etc.), genes regulating collagen synthesis (tgf-β, ctgf) and degradation (mmp2, mmp9, timp2, etc.) were down-regulated as temperature increased. Furthermore, the protein processing in endoplasmic reticulum (ER) pathway was significantly affected by temperature. The transcription of molecular chaperones of procollagen (hsp47, p4hb, sec24a, etc) in the pathway was significantly up-regulated in high temperature group. Notably, no significant difference in the hydroxyproline content was observed among groups, suggesting a temperature compensation mechanism may exist during collagen post-translational modification (hydroxylation, etc.). It was concluded that temperature exerted profound effects on muscle growth and collagen metabolism in zebrafish. Appropriate low temperature was suggested to enhance collagen deposition in fish muscle during aquaculture practice. Our data would enrich basic knowledge of regulatory mechanism of collagen metabolism in fish and help to develop strategy for producing fish products with higher quality.

FRQ-CK1 Interaction Underlies Temperature Compensation of the Neurospora Circadian Clock.

ABSTRACTTemperature compensation is a fundamental property of all circadian clocks; temperature compensation results in a relatively constant period length at different physiological temperatures, but its mechanism is unclear. Formation of a stable complex between clock proteins and casein kinase 1 (CK1) is a conserved feature in eukaryotic circadian mechanisms. Here, we show that the FRQ-CK1 interaction and CK1-mediated FRQ phosphorylation, not FRQ stability, are main mechanisms responsible for the circadian temperature compensation phenotypes in Neurospora. Inhibition of CK1 kinase activity impaired the temperature compensation profile. Importantly, both the loss of temperature compensation and temperature overcompensation phenotypes of the wild-type and different clock mutant strains can be explained by temperature-dependent alterations of the FRQ-CK1 interaction. Furthermore, mutations that were designed to specifically affect the FRQ-CK1 interaction resulted in impaired temperature compensation of the clock. Together, these results reveal the temperature-compensated FRQ-CK1 interaction, which results in temperature-compensated CK1-mediated FRQ and WC phosphorylation, as a main biochemical process that underlies the mechanism of circadian temperature compensation in Neurospora.

Graphene Oxide (GO) Coated Impedimetric Gas Sensor for Selective Detection of Carbon Dioxide (CO2) With Temperature and Humidity Compensation

Design and development of a low-cost, low-power, miniature, highly sensitive, and selective carbon dioxide (CO2) sensor is an active research area due to the rapid rise of CO2 closed to 408 ppm in the atmosphere because of the industrial revolution. This research proposes a highly sensitive planar interdigital sensor coated with graphene oxide (GO) to induce selectivity towards CO2. The performance of the sensor has been analysed with various temperatures, humidities, and different CO2 concentrations. The developed sensor has been characterised using Electrochemical Impedance Spectroscopy (EIS). The calibration standard has been developed for a range of CO2 concentrations from 400 ppm to 4000 ppm. The standard gas chromatography (GC) method is used to validate all the results. The temperature and humidity compensation mechanisms are also included to improve the detection ability for determining the CO2 gas concentration from unknown gas samples. Repeatability, reproducibility, stability, cross-sensitivity, response, and recovery time are also tested. The obtained results are highly encouraging to develop a low-cost smart CO2 gas sensing system for both indoor and outdoor environmental applications.

Quantifying Temperature Compensation of Bicoid Gradients with a Fast T-Tunable Microfluidic Device

As a reaction-diffusion system strongly affected by temperature, early fly embryos surprisingly show highly reproducible and accurate developmental patterns during embryogenesis under temperature perturbations. To reveal the underlying temperature compensation mechanism, it is important to overcome the challenge in quantitative imaging on fly embryos under temperature perturbations. Inspired by microfluidics generating temperature steps on fly embryos, here we design a microfluidic device capable of ensuring the normal development of multiple fly embryos as well as achieving real-time temperature control and fast temperature switches for quantitative live imaging with a home-built two-photon microscope. We apply this system to quantify the temperature compensation of the morphogen Bicoid (Bcd) gradient in fly embryos. The length constant of the exponential Bcd gradient reaches the maximum at 25°C within the measured temperatures of 18–29°C and gradually adapts to the corresponding value at new temperatures upon a fast temperature switch. The relaxation time of such an adaptation becomes longer if the temperature is switched in a later developmental stage. This age-dependent temperature compensation could be explained if the traditional synthesis-diffusion-degradation model is extended to incorporate the dynamic change of the parameters controlling the formation of Bcd gradients.

An Optical Fiber Twist Sensor With Temperature Compensation Mechanism Based on T-SMS Structure

A new optical fiber twist sensor with temperature compensation mechanism is designed and experimentally demonstrated. The main structure of this twist sensor is a torsion perturbation point cascaded with single mode-multimode-single mode (SMS) fiber structure. The experimental results show that the twist sensor has ability to distinguish the twist direction with sensitivities of 9.5 pm/° and 34.7 pm/° at the chosen dips in the range from −100° (CCW) to 140° (CW). Furthermore, the temperature response characteristic of the sensor is also researched through experiment. Temperature sensitivities of 71.8 pm/°C and 65.2 pm/°C can be obtained at the same dips in the range from 20 °C to 75 °C. In addition, the temperature's influence can be compensated with post-measurement calculation through the cross-matrix. The theoretical resolutions of twist and temperature simultaneous measurement are ±0.084° and ±0.32 °C, respectively.

Small core FBG-based temperature compensated ‘smart’ contact lens for effective intraocular pressure measurement

In this work, a small core, Fibre Bragg Grating (FBG)-based smart contact lens for intraocular pressure (IOP) measurement has been demonstrated. Further, an integral temperature compensation mechanism has been developed and included in the sensor design, allowing it to offer good long-term measurement capability while allowing for any local temperature fluctuations. The sensitivity of the device has been shown to be 12.9 p.m./mmHg, yielding good repeatability in tests carried out. Such a small core fibre, FBG-based smart contact lens shows significant potential for improving the management and therapy of glaucoma, the second most common cause of preventable blindness in the world.

Enhanced Reconfigurable Physical Unclonable Function Based on Stochastic Nature of Multilevel Cell RRAM

The physical unclonable function (PUF) based on resistive random-access memory (RRAM) possesses a distinctive advantage that can offer higher security and lower cost than the traditional complementary metal–oxide–semiconductor-based cryptographic devices and other conventional PUFs. The intrinsic stochasticity of RRAM devices successfully provides attractive properties to implement PUF. In this paper, we present a novel multistate-based RRAM PUF to realize strong tolerance against attack. By applying multilevel states with bit shuffling to the RRAM PUF, the randomness and uniqueness were enhanced close to ideal values. In addition, the bit error rate was dramatically reduced using the temperature compensation mechanism. Moreover, our new method not only enables the generation of larger challenge–response pairs (CRPs) with less footprint but also can reconfigure CRPs.

Arabidopsis JMJD5/JMJ30 Acts Independently of LUX ARRHYTHMO Within the Plant Circadian Clock to Enable Temperature Compensation.

The circadian system ensures that plants respond appropriately to environmental change by predicting regular transitions that occur during diel cycles. In order to be most useful, the circadian system needs to be compensated against daily and seasonal changes in temperature that would otherwise alter the pace of this biological oscillator. We demonstrate that an evening-phased protein, the putative histone demethylase JMJD5, contributes to temperature compensation. JMJD5 is co-expressed with components of the Evening Complex, an agglomeration of proteins including EARLY FLOWERING3 (ELF3), ELF4, and LUX ARRHYTHYMO (LUX), which also integrates temperature changes into the molecular clockwork. One role of the Evening Complex is to regulate expression of PSEUDORESPONSE REGULATOR9 (PRR9) and PRR7, important components of the temperature compensation mechanism. Surprisingly we find that LUX, but not other Evening Complex components, is dispensable for clock function at low temperatures. Further genetic analysis suggests JMJD5 acts in a parallel pathway to LUX within the circadian system. Although an intact JMJD5 catalytic domain is required for its function within the clock, our findings suggest JMJD5 does not directly regulate H3K36 methylation at circadian loci. Such data refine our understanding of how JMDJ5 acts within the Arabidopsis circadian system.

Design of Fully Automatic Drone Parachute System with Temperature Compensation Mechanism for Civilian and Military Applications

Application of Unmanned Aerial Vehicles (a.k.a. drones) is becoming more popular and their safety is becoming a serious concern. Due to high cost of top-end drones and requirements for secure landing, development of reliable drone recovery systems is a hot topic now. In this paper, we describe the development of a parachute system with fall detection based on accelerometer-gyroscope MPU – 6050 and fall detection algorithm based on the Kalman filter to reduce acceleration errors while drone is flying. We developed the compensation algorithm for temperature-related accelerometer errors. The parachute system tests were performed from a small height on a soft surface. Later, the system was tested under real-world conditions. The system functioned effectively, resulting in parachute activation times of less than 0.5s. We also discuss the civilian and military applications of the developed recovery system in harsh (high temperature) environment.

Influence of Temperature on the Dynamic Reading Performance of UHF RFID System: Theory and Experimentation

Abstract The radio frequency identification (RFID) system is vulnerable to a variety of factors (metal, liquid, temperature, and so on) in the practical application. In this paper, the reading distance of tags, as the evaluation criteria for the reading performance of the RFID system, is focused on to study the influence of environmental temperature on the dynamical performance of an ultra-high frequency (UHF) RFID system. An experimentation system, including temperature control system and detection platform, is devised to control temperature and measure the reading distance of the RFID tag. According to the experimental data of the tag's reading distance at different temperature, a fitting model between temperature and tag's reading distance is established. Experimental results show that the tag's reading distance decreases with the increase of temperature. Finally, the corresponding temperature compensation mechanism is deduced to get the reading distance under the same reference temperature. This paper provides an effective method for selection and evaluation of UHF RFID tags at different temperature.

Differential Phononic Crystal Sensor: Towards a Temperature Compensation Mechanism for Field Applications Development.

Phononic crystals are resonant structures with great potential to be implemented in applications as liquid sensors. The use of the symmetry reduction technique allows introducing relevant transmission features inside bandgaps by creating defect modes in a periodic regular structure. These features can be used as measures to quantify changes in the speed of sound of liquid samples that could be related to the concentration of analytes or the presence of pathogens among other interesting applications. In order to be able to implement this new technology in more challenging applications, such as biomedical applications, it is necessary to have a very precise and accurate measurement. Changes in temperature greatly affect the speed of sound of the liquid samples, causing errors in the measurements. This article presents a phononic crystal sensor that, by introducing additional defect modes, can carry out differential measurements as a temperature compensation mechanism. Theoretical studies using the transmission line model and analytes at various temperatures show that the proposed temperature compensation mechanism enhances the performance of the sensor in a significant way. This temperature compensation strategy could also be implemented in crystals with different topologies.