Constant Temperature Environment Research Articles

Fast and Precise Temperature Control for Axon Stretch Growth Bioreactor Based on Fuzzy PID Control.

A suitable environment is essential for successful long-term cell culturing in vitro. Too high or too low temperature will affect the growth of cells, so we need to maintain the constant temperature of the cell culture environment. Usually, cells are cultured in a cell incubator, and the constant temperature is provided by the cell incubator. Recently, we have developed a multi-channel axon stretch growth bioreactor for rapid acquisition of autologous nerve tissue. Since the motor and controller are placed in the incubator for a long time, the service life of the equipment will be shortened or even damaged due to high humidity and weak acid environment. In order to enable the axon stretch growth bioreactor to culture cells independently, we designed a constant temperature control system for the device. Firstly, the simulation results show that the fuzzy PID control reduces the overshoot and improves the traditional PID control with large overshoot and low control precision. Then, the two control algorithms were applied to the multi-channel axon stretch growth bioreactor by STM32F4 microcontroller. The experimental data show that the fuzzy PID control algorithm has good control effect and can meet the requirement of constant temperature of cell growth. Finally, nerve cells derived from human pluripotent stem cells were successfully cultured in a cell culture amplification chamber under a constant temperature environment provided by a fuzzy PID controller, and well-developed axons could be seen. In the future, we may transplant stretch growth axons into living organisms to repair nerve damage.

Research on heat transfer model of air permeability test device for food and drug soft packaging materials

The air permeability test of food/drug packaging materials such as plastic film and plastic sheet is indispensable in the process of sealing and preservation. During film permeability testing, a constant temperature environment needs to be maintained. In order to obtain satisfactory thermostatic control and reduce the influence of ambient temperature on test results, it is necessary to explore the heat transfer model of the permeability testing device. Firstly, the experimental platform is constructed with a Thermo Electric Cooling as the heat source and a thermometer as the temperature measurement element. Then, the three-dimensional heat transfer model of the food and drug soft packaging material permeability testing device was established, and the analytical solution of the temperature distribution function was obtained. Finally, the simulation and test results show that the proposed model is consistent with the experimental test results, and the model errors caused by the heat insulation or heat dissipation of the device can be ignored. This work provides a theoretical basis for further research on the air permeability test of soft packaging materials.

Utilization of carbonized water hyacinth for effective encapsulation and thermal conductivity enhancement of phase change energy storage materials

In this work, a biochar carrier was developed to adsorb phase change materials and enhance thermal conductivity. Six kinds of modified carbonized water hyacinth were prepared by freeze drying (or vacuum drying) combined with high-temperature carbonization. The pore volume and specific surface area (SSA) of FC900 are the highest, reaching 0.3153 cm3/g and 479.966 m2/g, which are 32% higher than those of VC900. The load rates of FC900 and VC900 on lauric acid-myristic acid-paraffin section (LMPS) are 75% and 65% respectively. Meanwhile, the phase transition enthalpy of LMPS/FC900 is 104.36 J/g, which is 20.75% higher than that of LMPS/VC900, and the phase transition temperatures are 25.93 and 26.77 °C respectively. After 500 times of heat storage and release experiments, LMPS/FC900 maintains a stable phase change peak, which has good thermal performance stability. Notably, the thermal conductivity of LMPS/FC900 is 0.4168 W/(m·K), which is 56.93% higher than that of LMPS. Otherwise, under the constant temperature environment of 50 °C, the heating time of LMPS/FC900 is 11.89% longer than that of LMPS/VC900, which has more excellent temperature control performance. This study concludes that the carbonization temperature of 900 °C and freeze-drying measures are the best preparation process for carbonized water hyacinth, and LMPS/FC900 has good thermal conductivity and phase change energy storage performance.

A fast temperature-programmed second-dimension column for comprehensive two-dimensional gas chromatography.

The short analysis time and constant temperature environment in the second dimension of two-dimensional comprehensive chromatography frequently causes wraparound problems, especially for complex high boilers. This problem can be solved by temperature programming on the second column, but since this requires heating and cooling the column in a matter of seconds, it is difficult to implement. In this study, we describe a method of accomplishing rapid heating and cooling with a resistively heated column cooled by compressed air. Critical to this method is minimizing the lag time between the actual temperature and the reported temperature by using the column heating element as the temperature sensor, virtually eliminating the danger of overshooting the temperature setpoint. This technique facilitates a ramp rate of up to 100°C/s with minimal overshooting-well beyond the requirements of gas chromatography. A single-layer column bundle design allows a compressed-air cooling device to cool the column from 200 to 50°C at an average rate of -21°C/s. The secondary dimension temperature programming is facilitated by the longer secondary dimension time made possible by the direct flow modulation method. We evaluated the performance of the single-layer column bundle and demonstrated this method by applying it to a gasoline sample. We also compared this method with the traditional isothermal approach and found that use of the secondary temperature program reduced the naphthalene retention time from 12.1 to 6.3s and its peak width at half height from 846 to 126ms.

Can Wheat Germination Test Be Used to Predict Pregnancy in Ewes?


 Several invasive diagnosis methods to predict pregnancy in humans and animals were used in the past. Since Antiquity, grains germination test was used to predict more safely the pregnancy in women in order to avoid the possibility of miscarriage. The abscisic acid is a component of pregnant females’ urine that prevents germination of grains. Considering this principle, 20 samples of urine were collected from 10 pregnant ewes and 10 from non-pregnant animals. After urinalysis, 15 ml urine sample was added to 20 grains of wheat in a Petri dish, followed by a dilution of 1:4 with distilled water. Only water has been added in the control sample. There were performed duplicates for each animal. For 10 days, all plates were kept in a constant environmental temperature (22°C) and humidity (42%). Statistical analysis revealed that after 5 and 10 days, wheat grains belonging to pregnant ewes were less germinated, and values regarding shoot length were lower than those from the control group. Even if the number of samples is small, it can be concluded that wheat germination test can be used to predict pregnancy in ewes.

Mechanism of energy conversion of ferroelectric in pyroelectric cycle

<p indent="0mm">“Waste heat” in the environment can be converted into electric energy by the Seebeck effect of semiconductor and pyroelectric effect of ferroelectrics ascribed to induction effect of polarization by electric field applied, energy conversion originates from the difference of polarization hysteresis electric field (<italic>P-E</italic>) loops between two different temperatures. Two isothermal processes and two iso-electric field processes form a pyroelectric cycle. By absorbing and releasing heat between two thermal reservoirs, a ferroelectric change its polarization successively so as to convert heat into electricity in a thermal-electric cycle, similar to the Carnot cycle. Output electric energy is the area enclosed by the cycle. For a constant high temperature environment, how to design a ferroelectric with proper Curie temperature and how to set cycling condition to match the temperatures to enlarge the area of a cycle are the two crucial problems. Experiment researches on pyroelectric energy conversion have been performed since the 1960s. The theoretic research was limited on simple expressions due to the difficulty on solving <italic>P-E</italic> loop. The <italic>P-E</italic> loop of ferroelectrics stems from rotation of dipoles and polarization hysteresis. In three-dimensional ferroelectrics, Gibbs free energies in the orientation directions of dipoles change with applied electric field differently, which causes changes in probabilities of dipole in different directions, i.e., rotation effect of dipoles. By introducing a coupling factor in the parallel dipoles the hysteresis effect was solved. The above solutions are extended to pyroelectric cycle to solve the problems referring to two isothermal processes and two iso-electric field processes with different initial condition. By combining the rotation effect and coupling effect that the coupling strength between dipoles is proportional to the rotated dipoles in the field direction during the field increasing process and persists to the same value in the field withdrawing process, mechanisms of polarization hysteresis are derived as several formulae. By editing a software program, numerical simulation method is used by setting values to the parameters to obtain evolution of polarization in the four processes of a cycle. Simulated result provides path of a cycle, depending on the maximal electric field (<italic>E</italic>_max). For a <italic>P-E</italic> loop in the first quadrant, there is a middle-curve rises from zero point to the top point of the loop, and an up-curve reduces from the top point to the remnant polarization at the zero field. In a cycle for a large enough <italic>E</italic>_max, the iso-low temperature process passes along the up-curve in the opposite direction, while for a smaller <italic>E</italic>_max, the process starts between the middle-curve and the up-curve and then transforms to the up-curve with the increase in the field because of impact of the small remnant polarization produced by <italic>E</italic>_max. The efficiency of pyroelectric cycling depends on cycling temperatures relative to Curie temperature and magnitude of the fields. High temperature is set above or below Curie temperature, and low temperature is set much below Curie temperature. Results show that when the low temperature is closer to Curie temperature, and high temperature is slightly higher than Curie temperature, pyroelectric energy conversion efficiency is higher and stable. When the high and low temperatures are close to the Curie temperature, the maximum pyroelectric conversion efficiency is obtained, but it decreases with the increase of the high temperature rapidly. A scaled efficiency, the efficiency relative to the Carnot cycle, decreases with the increase of temperature.

Experimental study on creep of short performance-based alkali-activated concrete column

Performance-based alkali-activated concrete overcomes the fatal disadvantage of short setting time and poor workability. In this paper, The creep test of this kind of concrete is carried out to explore the influence of strength grade and reinforcement ratio on the creep coefficient under the condition of constant temperature and humidity environment. Results show that specific creep and creep coefficient of alkali activated concrete decrease with strength grade. The ratio of creep coefficients of C30, C50 and C70 is 1:0.89:0.80. The creep coefficients were compared with the creep models adopted by the American Code, the European Code, and the Chinese Code, which are not suitable for predicting the creep coefficient of alkali-activated concrete. At the same time, considering the use of reinforcement in practical applications, the effect of reinforcement ratio on the creep coefficient of alkali-activated concrete is studied. The results show that reinforcement can reduce the creep coefficient. The greater the reinforcement ratio, the smaller the creep coefficient. The creep coefficient of alkali-activated concrete with reinforcement ratio of 1.1% and 2.0% is 11.1% and 18.7% smaller than that of concrete without reinforcement. Based on the aging theory method, according to the force balance condition and deformation coordination condition, the creep coefficient calculation formula considering the influence of the steel bar can be deduced. The theoretically calculated value is in good agreement with the measured data. This formula can be used to predict the creep coefficient of alkali-activated reinforced concrete.

Lithium Battery State-of-Charge Estimation Based on a Bayesian Optimization Bidirectional Long Short-Term Memory Neural Network

State of charge (SOC) is the most important parameter in battery management systems (BMSs), but since the SOC is not a directly measurable state quantity, it is particularly important to use advanced strategies for accurate SOC estimation. In this paper, we first propose a bidirectional long short-term memory (BiLSTM) neural network, which enhances the comprehensiveness of information by acquiring both forward and reverse battery information compared to the general one-way recurrent neural network (RNN). Then, the parameters of this network are optimized by introducing a Bayesian optimization algorithm to match the data characteristics of lithium batteries with the network topology. Finally, two sets of lithium battery public data sets are used to carry out experiments under different constant temperature and variable temperature environments. The experimental results show that the proposed model can effectively fit the actual measurement curve. Compared with traditional long short-term memory network (LSTM) and BiLSTM models, the prediction accuracy of the Bayes-BiLSTM model is the best, with a root mean square error (RMSE) within 1%, achieving a better ability for capturing long-term dependencies. Overall, the model exhibits high accuracy, adaptability, and generalization for the SOC estimation of batteries with different chemical compositions.

Effect of Constant Temperatures on Culicoides sonorensis Midge Physiology and Vesicular Stomatitis Virus Infection.

Simple SummaryCulicoides biting midges are nuisance pests of livestock and well-known vectors of veterinary arboviruses, such as vesicular stomatitis virus (VSV). Female midges ingest viruses when feeding on blood to obtain protein for egg-laying. After ingesting a VSV-infected blood meal, the environmental temperature of the resting location mediates the rates at which blood is digested, eggs are laid, and virus particles are replicated inside the midge. VSV transmission will occur if the timing of virus amplification aligns with the next feeding–egg-laying cycle. We evaluated the impact of constant environmental temperatures on midge physiology (lifespan and reproduction), vector competence for VSV (infection and dissemination), and thermal resting preference. Our results indicate that after ingesting a blood meal, most midges prefer to rest in areas that fall within their preferred physiological range regardless of the temperatures at which they were being maintained. These preferred temperatures maximized their survival, the number of egg-laying cycles, and the likelihood of VSV transmission. Our temperature approach shows that in the Culicoides–VSV system, the preferred resting temperature selected by blood-fed midges is beneficial for both insect and virus transmission.Culicoides midges play an important role in vesicular stomatitis virus (VSV) transmission to US livestock. After VSV-blood feeding, blood digestion followed by oviposition occurs while ingested virus particles replicate and disseminate to salivary glands for transmission during subsequent blood-feeding events. Changes to environmental temperature may alter the feeding–oviposition–refeeding cycles, midge survival, VSV infection, and overall vector capacity. However, the heterothermic midge may respond rapidly to environmental changes by adjusting their thermal behavior to resting in areas closer to their physiological range. Here we investigated the effects of four constant environmental temperatures (20, 25, 30, and 35 °C) on C. sonorensis survival, oviposition, and VSV infection, as well as resting thermal preferences after blood-feeding. We found that most midges preferred to rest in areas at 25–30 °C. These two constant temperatures (25 and 30 °C) allowed an intermediate fitness performance, with a 66% survival probability by day 10 and oviposition cycles occurring every 2–3 days. Additionally, VSV infection rates in bodies and heads with salivary glands were higher than in midges held at 20 °C and 35 °C. Our results provide insight into the implications of temperature on VSV–Culicoides interactions and confirm that the range of temperature preferred by midges can benefit both the vector and the arbovirus.

Convolutional neural network in the detection of gastrointestinal tumor and tap

At this stage, there are many studies on the pathological factors and prognosis of gastrointestinal cancer beds, but the results are different. Molecular biology and clinical studies have shown that tumor invasion and micrometastasis are likely to appear in the early stages of tumor occurrence. At present, the existing methods have poor specificity, low sensitivity, and long detection time. It is difficult to detect the occurrence or metastasis of tumors in time, and it is difficult to evaluate the efficacy in an early stage. Therefore, the detection of CTCs and their types in the peripheral blood of patients is of great significance in the early detection of tumor cell recurrence and metastasis, evaluation of prognosis and efficacy, determination of tumor molecular characteristics, and selection of appropriate individualized treatments. At the same time, the later the clinical pathological stage, the worse the prognosis, which has been widely confirmed in many studies. This study mainly explores the application of convolutional neural networks in gastrointestinal tumors and tap detection. In order to facilitate the construction, training, verification and testing of the target detection network, uses the python development language for code writing, and conducts the model training in the Ubuntu system environment. The model part is the constructed target detection network. This article uses 4 network model. Training refers to the update calculation of loss function and network. Adam optimization update network parameters, cross-entropy cost function is used to calculate category loss, and SmoothL1 is used to calculate position loss of border regression. The main function of recording is to record the loss function value and verification set accuracy data during the network training process and various detection data during the network training. During the TAP test, 20−30μl (2 drops) of blood from the end of the finger or earlobe of the subject is routinely collected and pushed into 2 large and uniform blood slices, placed in a constant temperature and humidity working environment, and placed flat. After the reaction is complete and the stain is dry, the results can be observed by microscope inspection. The colitis group was compared with the adenocarcinoma group, with statistical significance (P<0.05). This paper studies the gastrointestinal tumor detection method based on it, which will have important significance for the development and improvement of the automated auxiliary diagnosis technology of medical imaging.

Loop Heat Pipe Design: An Evaluation of Recent Research on the Selection of Evaporator, Wick, and Working Fluid

Abstract Since its invention nearly five decades ago, the loop heat pipe has revolutionized every application requiring cooling or maintaining a constant temperature environment. In this article, its various designs aspects are explored, which include design of the evaporator, wick, and selection of working fluid. Factors such as design guidelines and how they affect the physics of the overall system are surveyed. For the evaporator part, its various designs and their respective applications/operating ranges are reviewed. In the wick section, recent trends on its fabrication and performance enhancement are shown. A special section on how the wick functions is added, with a focus on the study of liquid–vapor meniscus using the thin-film evaporation theory. Attention is also given to the investigations on the various figures of merit used for the selection of the working fluid. For the first time, these figures of merit are categorized with respect to the device physics they represent/simulate. In the end, this review article also touches upon the various creative designs and ideas used to enhance the loop heat pipe performance.

Experimental Study on Corrosion of Galfan‐Coated Full‐Locked Coil Ropes in a Natatorium Environment

Galfan‐coated full‐locked coil rope is widely applied in long‐span spatial structures because of its high strength and lightweight. However, the corrosion problem is relatively serious in the natatorium, which affects the structure’s durability. To deeply reveal the corrosion mechanism of Galfan‐coated cable, this study first measured the natatorium on‐site, and the results indicated that the natatorium environment can be simulated by a constant temperature and humidity environment in engineering. Then, the constant temperature and humidity corrosion test was carried out to simulate the corrosion of Galfan‐coated cable with a certain amount of chloride ions on the surface, and the early corrosion rate was obtained. Later, the neutral salt spray accelerated corrosion test was carried out to predict the corrosion rate of the cable in the natatorium environment in the middle and late periods. The specimens included no‐stress unprotected coating cable, high‐stress unprotected coating cable, and high‐stress protected coating cable. The results show that high stress will accelerate the corrosion, and a protective coating can effectively prevent the corrosion. Finally, the linear model, bilinear model, and bilinear model considering chloride ion accumulation were proposed to study the corrosion of the Galfan coating. The results show that the linear model overestimates the corrosion rate, and the bilinear model and bilinear model considering chloride ion accumulation are practical. Meanwhile, corresponding maintenance suggestions were given for the natatorium project to improve the structure's durability.

Effect of geometrical design on the latent heat cooling properties of a lightweight two-phase composite

Latent heat storage materials undergo phase changes to maintain a constant temperature environment and are fast emerging as a passive “green” technology for thermal management. Phase-change materials (PCMs) typically have poor thermal conductivities; however, their response to rapid fluctuations in temperature can be sluggish. Here, we explore the feasibility of adding various aluminum alloy (AlSi10Mg) structures to speed up the thermal response. The cooling performance of various geometries with the same mass density was first investigated, and the best performing geometries were then further optimized to investigate the possible weight savings. Our results indicate that, for unidirectional heat flux, designs with 3D periodicity, such as triply periodic minimal surfaces, do not perform as well as those with 1D (parallel plates) and 2D (honeycombs) periodicity. Furthermore, a strong correlation was found between the cooling performance and the interfacial area density. An expanding melt front, which leads to an increase in the interfacial area for heat transfer over time, and even heat distribution were also observed to be advantageous. After optimization, the honeycomb design with tapered triangular rods surrounded by the PCM matrix was able to achieve greatest weight savings for a given performance requirement. Compared to a thermal management panel consisting solely of the PCM, it was able to keep a heated surface cooler by 90% and also outperformed a pure Al panel despite being more than 40% lighter.

Nanofibrous membrane through multi-needle electrospinning with multi-physical field coupling

The mass electrospinning is the key way to promote the industrial application of nanofibrous membrane, in which the multi-parameter controlling is the challenge for the multi-needle electrospinning. A constant temperature and humidity environment was introduced to studied the effect of process parameters on the ejection process of multi-needle electrospinning process. This article focused on the nanofiber deposition behaviors of multi-needle electrospinning from two different polymer solution of aqueous solution of poly (ethylene oxide) and the non-aqueous solution of polyvinylidene fluoride. We found that the same humidity has opposite effects on the deposition morphology of the water-soluble material PEO and the non-water-soluble material PVDF electrospun fiber. At the same time, we explored the effects of solution conductivity, solvent volatility, temperature and viscosity on electrospinning on water-insoluble and water-soluble materials. What this paper aim is to provide a process debugging reference for the batch preparation of nanofibers of different materials by multi-needle electrospinning.

Identification of antemortem and postmortem fractures in a complex environment by FTIR spectroscopy based on a rabbit tibial fracture self-control model.

The identification of antemortem and postmortem fractures is a critical and challenging task for forensic researchers. Based on our preliminary studies, we explored whether the combination of Fourier transform infrared spectroscopy (FTIR) and chemometrics can identify antemortem and postmortem fractures in complex environments. The impacts of the four environments on the bone spectrum were analyzed by principal component analysis (PCA). It was found that the bone degradation rate in the submerged and ground surface (GS) environments was higher than that in the buried and constant temperature and moisture (CTM) environments. Additionally, the bone degradation rate in buried environment higher than that in the CTM environment. The average spectrum, PCA and partial least squares discriminant analysis (PLS-DA) results all revealed that there were significant differences between the antemortem fracture and the remaining three groups in a complex environment. Compared with the antemortem fracture, the antemortem fracture control (AFC) and postmortem fracture control (PFC) tended to be more similar to the postmortem fracture. According to the loading plot, amide I and amide II were the main components that contributed to the identification of the antemortem fracture, AFC, postmortem fracture, and PFC. Finally, we established a differential model for the antemortem and postmortem fractures (an accuracy of 96.9%), and a differentiation model for the antemortem fracture, AFC, postmortem fracture, and PFC (an accuracy of 87.5%). In conclusion, FTIR spectroscopy is a reliable tool for the identification of antemortem and postmortem fractures in complex environments.

Temperature and its control in molecular dynamics simulations

ABSTRACT The earliest molecular dynamics simulations relied on solving the Newtonian or equivalently the Hamiltonian equations of motion for a system. While pedagogically very important as the total energy is preserved in these simulations, they lack any relationship with real-life experiments, as most of these tests are performed in a constant temperature environment that allows energy exchanges. So, within the framework of molecular dynamics, the Newtonian evolution equations need to be modified to enable energy exchange between the system and the surroundings. The prime motive behind allowing energy exchange is to control the temperature of the system. Depending on the temperature being controlled and the modifications made to the equations of motion, different evolution equations, or thermostat algorithms, can be obtained. This work reviews the recent developments in controlling temperature through deterministic algorithms. We highlight the physical basis behind the algorithms, their advantages, and disadvantages, along with the situations where they are applicable. The review ends with a brief discussion on open-ended questions related to thermostatted dynamics.

Evolution of a Non-Hermitian Quantum Single-Molecule Junction at Constant Temperature.

This work concerns the theoretical description of the quantum dynamics of molecular junctions with thermal fluctuations and probability losses. To this end, we propose a theory for describing non-Hermitian quantum systems embedded in constant-temperature environments. Along the lines discussed in [A. Sergi et al., Symmetry 10 518 (2018)], we adopt the operator-valued Wigner formulation of quantum mechanics (wherein the density matrix depends on the points of the Wigner phase space associated to the system) and derive a non-linear equation of motion. Moreover, we introduce a model for a non-Hermitian quantum single-molecule junction (nHQSMJ). In this model the leads are mapped to a tunneling two-level system, which is in turn coupled to a harmonic mode (i.e., the molecule). A decay operator acting on the two-level system describes phenomenologically probability losses. Finally, the temperature of the molecule is controlled by means of a Nosé-Hoover chain thermostat. A numerical study of the quantum dynamics of this toy model at different temperatures is reported. We find that the combined action of probability losses and thermal fluctuations assists quantum transport through the molecular junction. The possibility that the formalism here presented can be extended to treat both more quantum states () and many more classical modes or atomic particles () is highlighted.

A preliminary study of the weathering mechanism of fossilized Cretaceous Hamipterus bones

The discovery of Hamipterus tianshanensis had important scientific significance because three-dimensional preserved fossils can provide unique information about the reproduction, development, and evolution of pterosaurs. However, the pterosaur fossils exhibited violent weathering, including noticeable cracking and spalling, since the preservation environment changed dramatically after excavation, which severely influenced the preservation of these fossils and the scientific research conducted on them. To determine the weathering mechanism of these fossil bones, the samples were analyzed using X-ray fluorescence (XRF), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy and energy dispersive spectrometry (SEM-EDS). The results indicate that calcite is the main mineral in the hollow bones, but it is mixed with a small amount of other minerals, such as quartz, feldspar, and other debris particles. Moreover, the main component of the pterosaur bones is hydroxyapatite, and carbonate has substituted for some of the phosphate (B-type carbonated apatite) in the fossil bones. A small amount of calcite and manganese oxides has precipitated in the vascular canals. The phosphate crystallinity index (PCI) is 4.17. These results indicate that the fossils have undergone severe diagenesis. Apart from these alterations, the fossil bones have high contents of anions and cations such as Cl−, NO3−, SO42−, Na+, and Ca2+, and the total content of soluble salts is 35584.41 μg g−1. Based on these results, it is inferred that the weathering mechanism of the fossil bones is as follows. First, the fragile hollow bones cracked easily because of the enormous thermal stress caused by the dramatic temperature changes in the Gobi Desert and the differences in the thermal expansion coefficients (TEC) of the surrounding rocks, the fossil bones, and the different fillers. Second, a large amount of stress is generated by salt crystallization when the temperature and humidity change, and the pterosaur fossils will be damaged when the crystallization pressure exceeds the tensile strength of the fossils. These results suggest that the preservation of pterosaur fossils requires suitable desalination and consolidation conditions. Moreover, they should be preserved in a constant temperature and humidity environment.

Testing multiple drivers of the temperature‐size rule with nonlinear temperature increase

Abstract The temperature‐size rule (TSR) describes the inverse relationship between organism size and environmental temperature in uni‐ and multicellular species. Despite the TSR being widespread, the mechanisms for shrinking body size with warming remain elusive. Here, we experimentally test three hypotheses (differential development and growth [DDG], maintain aerobic scope and regulate oxygen supply [MASROS] and the supply–demand [SD] hypothesis) potentially explaining the TSR using the aquatic protist Colpidium striatum in three gradually changing and one constant temperature environment crossed with three different nutrient levels. We find that the constant and slowly warming environments show similar responses in terms of population dynamics, whereas populations with linear and fast warming quickly decline and show a stronger temperature‐size response. Our analyses suggest that acclimation may have played a role in observing these differences among treatments. The SD hypothesis is most parsimonious with the data, however, neither the DDG nor the MASROS hypothesis can be firmly dismissed. We conclude that the TSR is driven by multiple ecological and acclimatory responses, hence multicausal. A free Plain Language Summary can be found within the Supporting Information of this article.

Casimir force and its effects on pull-in instability modelled using molecular dynamics simulations.

We present a new methodology to incorporate the Casimir forces within the molecular dynamics (MD) framework. At atomistic scales, the potential energy between two particles arising due to the Casimir effect can be represented as U(r ij ) = C/r 7. Incorporating the Casimir effect in MD simulations requires the knowledge of C, a problem hitherto unsolved. We overcome this by equating the total potential energy contributions due to each atomistic pair with the potential energy of continuum scale interacting bodies having similar geometries. After having identified the functional form of C, standard MD simulations are augmented with the potential energy contribution due to pairwise Casimir interactions. The developed framework is used to study effects of the Casimir force on the pull-in instability of rectangular and hollow cylindrical shaped deformable electrodes separated by a small distance from a fixed substrate electrode. Our MD results for pull-instability qualitatively agree with the previously reported analytical results but are quantitatively different. The effect of using longer-ranged Casimir forces in a constant temperature environment on the pull-in behaviour has also been studied.