Induced Temperature Changes Research Articles

Heat application in live cell imaging.

Thermal heating of biological samples allows to reversibly manipulate cellular processes with high temporal and spatial resolution. Manifold heating techniques in combination with live-cell imaging were developed, commonly tailored to customized applications. They include Peltier elements and microfluidics for homogenous sample heating as well as infrared lasers and radiation absorption by nanostructures for spot heating. A prerequisite of all techniques is that the induced temperature changes are measured precisely which can be the main challenge considering subcellular structures or multicellular organisms as target regions. This article discusses heating and temperature sensing techniques for live-cell imaging, leading to future applications in cell biology.

Overview of the Design and Application of Photothermal Immunoassays.

Developing powerful immunoassays for sensitive and real-time detection of targets has always been a challenging task. Due to their advantages of direct readout, controllable sensing, and low background interference, photothermal immunoassays have become a type of new technology that can be used for various applications such as disease diagnosis, environmental monitoring, and food safety. By modification with antibodies, photothermal materials can induce temperature changes by converting light energy into heat, thereby reporting specific target recognition events. This article reviews the design and application of photothermal immunoassays based on different photothermal materials, including noble metal nanomaterials, carbon-based nanomaterials, two-dimensional nanomaterials, metal oxide and sulfide nanomaterials, Prussian blue nanoparticles, small organic molecules, polymers, etc. It pays special attention to the role of photothermal materials and the working principle of various immunoassays. Additionally, the challenges and prospects for future development of photothermal immunoassays are briefly discussed.

An Evaluation of the Impact Effect on the Surface Microstructure and Its Induced Temperature Changes during Ultrasonic-Assisted Micro-Forging.

In the field of ultrasonic-assisted micro-forming, in addition to acoustic softening, impact effects also play a significant role, especially in terms of influencing the deformation behavior of surfaces, such as by generating more deformation on surface asperity. In this study, to understand the mechanisms involved in the effect of an impact, ultrasonic-assisted micro-forging tests were conducted on commercially pure copper, pure aluminum, and pure titanium. A method that can measure the increment in the temperature during ultrasonic vibration was developed. As a result, changes in the surface temperature of the material under the impact effect and acoustic softening were measured. It is indicated that, during ultrasonic vibration, the heat generated through acoustic softening is very limited and the main heat increase occurs after the impact effect. Once the impact effect occurs, the surface temperature increases with increasing amplitude. Nevertheless, for materials with different crystal structures, the influences of the impact effect are also different. The surfaces of copper and aluminum soften, creating more surface deformation, but the exact opposite effect is seen on a titanium surface. Observing the evolution of the microstructure on the material surface with EBSD demonstrates that the impact effect on FCC materials can reach deeper below the surface in terms of temperature diffusion compared to titanium. Meanwhile, the impact effect in the case of titanium causes the regeneration of twinning, which is reduced under the influence of the acoustic softening effect, consequently resulting in strain hardening.

The study on the coupled influence of water saturation on heat and mass transfer processes within porous media under CW laser irradiation

Continuous wave (CW) laser irradiation induces temperature changes in various phases within porous media, accompanied by phase change and gas transport. Water saturation is a crucial factor influencing this context's moisture and heat transfer process. This paper addresses this issue by establishing a theoretical model for CW laser irradiation on unsaturated porous media. Through experiments and simulations, it studies the effects of different water saturations on heat and mass transfer under laser irradiation. The results indicate that the critical depth reflects the influence of water saturation under laser irradiation on the distribution of solid-phase temperature in both time and space dimensions. Specifically, an increase in water saturation enhances the uniformity of solid-phase temperature distribution, while the gas temperature exhibits a similar distribution pattern. For mass transfer processes, it increases the evaporation rate and Darcy velocity of porous media within the effective range of laser irradiation. Lower water saturation facilitates phase change processes and accelerates gas transport rates. Importantly, this trend remains consistent even with the emergence of dry-saturation zones. Additionally, the decrease in water saturation has a coupled promoting effect on gas temperature and mass transfer processes. Lowering water saturation can increase gas temperature and consequently enhance mass transfer processes. Simultaneously, enhancing mass transfer processes benefits heat exchange between the two phases. In the four sets of experiments, the conformity of the surface temperature rise curves obtained from experiments and simulations is good, indicating that the model can accurately reflect the temperature rise patterns of sand particles. In summary, this work provides valuable research results on the effects of different water saturations on laser irradiation-induced temperature rise, phase change, and gas and moisture transport within porous media. It lays a specific theoretical foundation for laser soil remediation technology.

Evolution of the Climate Forcing During the Two Years After the Hunga Tonga‐Hunga Ha'apai Eruption

AbstractWe calculate the climate forcing for the 2 ys after the 15 January 2022, Hunga Tonga‐Hunga Ha'apai (Hunga) eruption. We use satellite observations of stratospheric aerosols, trace gases and temperatures to compute the tropopause radiative flux changes relative to climatology. Overall, the net downward radiative flux decreased compared to climatology. The Hunga stratospheric water vapor anomaly initially increases the downward infrared radiative flux, but this forcing diminishes as the anomaly disperses. The Hunga aerosols cause a solar flux reduction that dominates the net flux change over most of the 2 yrs period. Hunga induced temperature changes produce a decrease in downward long‐wave flux. Hunga induced ozone reduction increases the short‐wave downward flux creating small sub‐tropical increase in total flux from mid‐2022 to 2023. By the end of 2023, most of the Hunga induced radiative forcing changes have disappeared. There is some disagreement in the satellite measured stratospheric aerosol optical depth (SAOD) observations which we view as a measure of the uncertainty; however, the SAOD uncertainty does not alter our conclusion that, overall, aerosols dominate the radiative flux changes.

Uncertainty assessment of thermal recovery and subsurface temperature changes induced by high-temperature aquifer thermal energy storage (HT-ATES): A case study

High-temperature aquifer thermal energy storage (HT-ATES) systems can store renewable-based or waste heat in the subsurface on a seasonal scale and may thus reduce the carbon footprint of future heat supply systems. Thermal recovery, i.e. the ratio of extracted to injected heat over one cycle, is required in a pre-application assessment because it determines the operational and economic viability of a HT-ATES system. The induced temperature changes in the subsurface are required to obtain the legal permits and are of interest for the design of a monitoring network. However, uncertainty in our knowledge on subsurface hydraulic and thermal parameters translates into uncertainties of the expected thermal recovery and the temperature changes induced during HT-ATES operation. In order to address these uncertainties for a case study in Hamburg, Germany, we use numerical modeling of the coupled thermo-hydraulic processes during the design stage of a HT-ATES system, based on a realistic load curve and the local geological setting of the storage aquifer. An ensemble of 50 scenarios was parameterized based on site-specific parameter uncertainties using Latin hypercube sampling to reflect the global parameter distributions, and the HT-ATES operation was simulated over a period of 26 years in each case. Most of the scenarios show high thermal recoveries with a median of 89 % in the 26th year, with thermal recovery most sensitive to the vertical hydraulic conductivity. The expected temperature distribution is well defined by the ensemble of model simulations, with far-field temperature changes reaching for hundreds of meters and showing greater variability between scenarios than those in the near-field region of the warm HT-ATES well on the tens of meters scale. Locations with large temperature differences between scenarios are identified as suitable for the placement of temperature monitoring wells. The presented work thus contributes directly to the design and permitting of HT-ATES systems and can also be used for uncertainty assessment of future HT-ATES plants and the identification of suitable monitoring setups.

Local tuning of Rydberg exciton energies in nanofabricated Cu2O pillars

Rydberg excitons in Cu2O feature giant optical nonlinearities. To exploit these nonlinearities for quantum applications, the confinement must match the Rydberg blockade size, which in Cu2O could be as large as a few microns. Here, in a top-down approach, we show how exciton confinement can be realised by focused-ion-beam etching of a polished bulk Cu2O crystal without noticeable degradation of the excitonic properties. The etching of the crystal to micron sizes allows for tuning the energies of Rydberg excitons locally, and precisely, by optically induced temperature change. These results pave the way for exploiting the large nonlinearities of Rydberg excitons in micropillars for making non-classical light sources, while the precise tuning of their emission energy opens up a viable pathway for realising a scalable photonic quantum simulation platform.

Study of air flow and heat transfer in soybean piles based on CT

The airflow within the grain pile is directly influenced by the 3D structure of the pores. The airflow distribution will further induce temperature changes within the grain pile, ultimately affecting the safety of grain storage. A quantitative analysis of the porosity, pore size and fractal dimension of the soybean grain pile is performed using computed tomography (CT). Then, the geometric modeling of the soybean grain pile is established by iterative reconstruction technology. Finally, the distribution of airflow and temperature fields in soybean grain piles is analyzed by finite element numerical simulation. It is found that the pore equivalent diameter, throat diameter and throat length are mainly within the 2–5 mm, 0–2 mm, and 3–6 mm, respectively. The results of the numerical simulation of the pressure drop of soybean grain piles are well agreed with the Nemec formula and the measurement values. Pressure diminishes along the airflow direction, with a substantially greater drop observed in vertical ventilation compared to horizontal ventilation. The airflow traverses the channel with a larger radius, while the velocity in a single pore gradually diminishes from the center to the wall. The intricate features of the pore structure significantly influence the distribution of airflow within the grain pile. This phenomenon results in an imbalance of heat transfer within the grain pile, thereby manifesting as discernible heterogeneity in both velocity and temperature distributions. The relevant research methods and conclusions can provide theoretical support and guidance for the multifield coupling theory of grain storage and grain storage safety research.

Numerical modelling of Energy Quay Walls to assess their thermal be-haviour

The use of the subsurface as a heating and cooling source through shallow geothermal installations has increased in the last decades [10]. So-called Energy Geostructures (EGs) represent a more innovative technology, serving the dual purpose of providing structural support to the ground/building and exchanging heat with the ground [2]. EGs can serve the purposes of several energy applications: they can be coupled with ground source heat pumps to provide space heating and cooling as well as domestic hot water.
 Energy sheet pile walls (ESPs) are a novel type of EG consisting of sheet pile walls equipped with steel pipe heat exchangers. When they are used to support the banks of canals or in port docks, they allow extraction of thermal energy from both soil and water [12]. The latter are called Energy quay walls (EQW) and are currently experimented at selected sites along canals in the Netherlands [7]. The energy efficiency of EQWs is expected to be influenced by the undisturbed ground temperature profile, ground thermal conductivity and thermal capacity, and operational and construction parameters [8] [9]. However, due to the lack of standard methods for the design of EQWs, further studies are needed to fully understand both their thermal and thermo-mechanical behaviour [1]. Based on the data collected from an EQW test field installed in Delft (NL) (Figure 1(a)), a Finite Element (FE) numerical model was developed for the accurate 3D analysis of the heat exchange phenomena taking place in the EQW.
 The EQW test site is characterized by two different heat exchanger types: the first one reaches 3 m depth and is aimed at exchanging heat mostly with the canal water. The second one has a depth of 15 m and exchanges heat with both water and soil. A monitoring system was installed composed by a total of 56 thermistors, 20 thermowells and 5 flowmeters to measure respectively the soil and canal water temperature, the heat exchanger fluid temperature and the flow velocity of both heat exchanger fluid and canal water. Different thermal activation combinations of deep and shallow loops were tested to assess the EQW thermal behaviour and the induced temperature changes into the soil [5].
 To analyse in detail the EQW thermal performance, the FE numerical model was built with the COMSOL Multiphysics software. The considered heat exchange processes are convection within the heat-carrier fluid and between the canal and the soil, and conduction in the soil and other solid domains. Radiation phenomena were considered negligible in the model. The FE model was set up using the built-in “heat transfer in pipes” module allowing quicker computations by representing heat exchanger pipes in a simplified 1D fashion. The domain dimension was chosen in order to keep the lateral and bottom surfaces far enough from the EQW, to avoid boundary effects. For the boundary conditions, a fixed temperature of 12°C [3] was assigned to the bottom domain boundary while the detected air temperature time history was assigned to the top of the domain. Thermal insulation was assigned to the lateral boundary surfaces. The water canal was directly simulated as part of the domain. The heat convective flow of water was taken into account by using inflow and outflow boundary conditions and by assigning to the canal the detected water velocity. A thermal initialization calculation was performed to start the calculation with accurate initial conditions in terms of temperature distribution within the domain [6]. The thermal conductivity, specific heat capacity and density of the different soil layers were determined through empirical correlations based on cone penetration tests results carried out near the EQW [11], corroborated by literature datasets based on the geological characterization of the soil [4]. Heat exchange between the EQW and the surrounding soil was simulated by activating the heat transfer flow within the pipes, assigning the measured inlet temperature and fluid velocity.
 An example comparison between the measured gained thermal power and the simulated results for the first 200 days of thermal activation of the EQW is shown in Figure 1(b). Except for the first 20 days of thermal activation, characterised by unreliable measurements because both the heat pump and the monitoring system were being tested to check the integrity of the system, it can be observed that the numerical simulation effectively reproduces the gained thermal power, as well as the induced temperature changes into the soil (not shown for the sake of brevity).
 After model validation against the data collected from the test field research activities continue. Further numerical parametric analyses are performed to identify the best combination of design and site parameters to maximize the energy efficiency. Additionally thermo-mechanical analyses are used to assess the magnitude of thermally induced displacements and stresses.

Elastocaloric Effect in Graphene Kirigami.

Kirigami, a traditional Japanese art of paper cutting, has recently been explored for its elastocaloric effect (ECE) in kirigami-based materials (KMs), where an applied strain induces temperature changes. Importantly, the feasibility of a nanoscale graphene kirigami monolayer was experimentally demonstrated. Here, we investigate the ECE in GK representing the thinnest possible KM to better understand this phenomenon. Through molecular dynamics simulations, we analyze the temperature change and coefficient of performance (COP) of GK. Our findings reveal that while GKs lack the intricate temperature changes observed in macroscopic KMs, they exhibit a substantial temperature change of approximately 9.32 K (23 times higher than that of macroscopic KMs, which is about 0.4 K) for heating and -3.50 K for cooling. Furthermore, they demonstrate reasonable COP values of approximately 1.57 and 0.62, respectively. It is noteworthy that the one-atom-thick graphene configuration prevents the occurrence of the complex temperature distribution observed in macroscopic KMs.

A Laser-Driven Microrobot for Thermal Stimulation of Single Cells.

Here, the study presents a thermally activated cell-signal imaging (TACSI) microrobot, capable of photothermal actuation, sensing, and light-driven locomotion. The plasmonic soft microrobot is specifically designed for thermal stimulation of mammalian cells to investigate cell behavior under heat active conditions. Due to the integrated thermosensitive fluorescence probe, Rhodamine B, the system allows dynamic measurement of induced temperature changes. TACSI microrobots show excellent biocompatibility over 72hin vitro, and they are capable of thermally activating single cells to cell clusters. Locomotion in a 3D workspace is achieved by relying on thermophoretic convection, and the microrobot speed is controlled within a range of 5-65µm s-1 . In addition, light-driven actuation enables spatiotemporal control of the microrobot temperature up to a maximum of 60°C. Using TACSI microrobots, this study targets single cells within a large population, and demonstrates thermal cell stimulation using calcium signaling as a biological output. Initial studies with human embryonic kidney 293 cells indicate a dose dependent change in intracellular calcium content within the photothermally controlled temperature range of 37-57°C.

Direct Electrocaloric Characterization of Ceramic Films.

Reliable and accurate characterization of the electrocaloric effect is necessary to understand the intrinsic properties of materials. To date, several methods are developed to directly measure the electrocaloric effect. However, each of them has some limitations, making them less suitable for characterizing ceramic films, which rely almost exclusively on less accurate indirect methods. Here, a new approach is proposed to address the process of rapid heat dissipation in ceramic films and to detect the electrically induced temperature change before it thermally bonds with the surrounding elements. By using a polymer substrate that slows heat dissipation to the substrate and fast infrared imaging, a substantial part of the adiabatic electrocaloric effect in Pb(Mg1/3 Nb2/3 )O3 -based ceramic films is captured. Infrared imaging provides a robust technique to reduce the ratio between the adiabatic and the measured electrocaloric temperature change in micrometer-sized ceramic films to a single-digit number, ≈3.5. The obtained results are validated with another direct thermometric method and compared with the results obtained with an indirect approach. Despite different measurement principles, the results obtained with the two direct methods agree well. The proposed approach is timely and can open a door to verify the predicted giant electrocaloric effects in ceramic films.

N°368 – Non-neurologic diseases mimicking stiff person syndrome

In climate modelling, a critical issue is the accurate representation of urban areas in space and variation over time. Urban features may be parameterised through urban canopy parameters (UCPs), including the impervious surface area (ISA). One of the aims of the Consortium for Small-scale Modelling (COSMO) and the CLM-Community is to improve urban numerical weather prediction (NWP) and climate simulations by implementing the urban canopy scheme TERRA_URB in the ICOsahedral Nonhydrostatic (ICON) modelling framework. To harmonise and update the datasets adopted for the UCPs, the Consortium has launched the Priority Project “City Induced Temperature change Through A'dvanced modelling” (PP CITTÀ). Within this framework, the study explores recent and detailed land cover datasets to update ISA and harmonise it with datasets adopted for the UCPs. We identify and compare some relevant datasets at the pan-European level. The results show the benefits obtained by correlating the UCPs from urban Local Climate Zones taken from the ECOCLIMAP-Second Generation with the ISA depending on the imperviousness degree provided by the Copernicus Land Monitoring Service. These results will foster an updating of NWP and climate models with urban surface parameterisations to match urban features while avoiding inconsistencies consistently.

Survey of land cover datasets for updating the imperviousness field in urban parameterisation scheme TERRA_URB for climate and weather applications

In climate modelling, a critical issue is the accurate representation of urban areas in space and variation over time. Urban features may be parameterised through urban canopy parameters (UCPs), including the impervious surface area (ISA). One of the aims of the Consortium for Small-scale Modelling (COSMO) and the CLM-Community is to improve urban numerical weather prediction (NWP) and climate simulations by implementing the urban canopy scheme TERRA_URB in the ICOsahedral Nonhydrostatic (ICON) modelling framework. To harmonise and update the datasets adopted for the UCPs, the Consortium has launched the Priority Project “City Induced Temperature change Through A'dvanced modelling” (PP CITTÀ). Within this framework, the study explores recent and detailed land cover datasets to update ISA and harmonise it with datasets adopted for the UCPs. We identify and compare some relevant datasets at the pan-European level. The results show the benefits obtained by correlating the UCPs from urban Local Climate Zones taken from the ECOCLIMAP-Second Generation with the ISA depending on the imperviousness degree provided by the Copernicus Land Monitoring Service. These results will foster an updating of NWP and climate models with urban surface parameterisations to match urban features while avoiding inconsistencies consistently.

Charge‐Density Wave Driven Giant Thermionic‐Current Switching in 1T‐TaS2/2H‐TaSe2/2H‐MoS2 Heterostructure

Abstract1T‐TaS2 exhibits several resistivity phases due to the modulation of charge density wave (CDW). The fact that such phase transition can be driven electrically has attracted a lot of attention in the recent past toward active‐metal based electronics. However, the bias‐driven resistivity switching is not very large (less than five‐fold), and an enhancement in the same will highly impact such phase transition devices. One aspect that is often overlooked is that such phase transition is also accompanied by a significant change in the local temperature due to the low thermal conductivity of 1T‐TaS2. In this work, such electrically driven phase transition induced temperature change is exploited to promote carriers over a thermionic barrier in a 1T‐TaS2/2H‐TaSe2/2H‐MoS2 T‐Junction, achieving a 964‐fold abrupt switching in the current through the MoS2 channel. The device is highly reconfigurable and exhibits an abrupt reduction in current as well when the biasing configuration changes. The results are promising for several electronic applications, including neuromorphic chips, switching, nonlinear devices, and industrial electronics such as current and temperature sensing.

Numerical study on the thermo-hydro-mechanical behaviour of an energy tunnel in a coarse soil

By installing heat exchange pipes in tunnel linings, tunnels can provide energy for heating and cooling of adjacent buildings, while being structurally load-bearing. However, energy production through ground heat exchange induces temperature changes, which can in turn result in additional deformation and stress. This study investigated the coupled thermo-hydro-mechanical behaviour of a tunnel equipped with heat exchanger pipes, accounting for heat transfer, groundwater flow and mechanical response of soil and tunnel lining, through numerical simulations. The proposed model was validated against monitoring data at the real scale available in the literature. The influence of groundwater conditions and ground thermal parameters on the mechanical performance is also investigated. The results under different configurations show that the maximum thermally-induced stress and deformation are within the acceptable range, and the tunnel stability is not affected significantly during a one-year thermal operation cycle. It is shown that the impact of ground thermal properties on the lining internal stress also depends on groundwater conditions. In addition, mechanical responses at the joints between the segments are less affected by thermal activation than the other parts of the segmental lining. The coupled numerical model presented can be further used to better understand the effects of heat transfer, water flow and thermal properties on tunnel structural mechanics during heating and cooling modes, both for safe design and sustainable operation of an energy tunnel system in the long term.

Ferroelectric Smectic Liquid Crystals as Electrocaloric Materials

The 1980s saw the development of ferroelectric chiral smectic C (SmC*) liquid crystals (FLCs) with a clear focus on their application in fast electro-optic devices. However, as the only known fluid ferroelectric materials, they also have potential in other applications, one of which is in heat-exchange devices based on the electrocaloric effect. In particular, ferroelectric liquid crystals can be both the electrocaloric material and the heat exchanging fluid in an electrocaloric device, significantly simplifying some of the design constraints associated with solid dielectrics. In this paper, we consider the electrocaloric potential of three SmC* ferroelectric liquid crystal systems, two of which are pure materials that exhibit ferroelectric, antiferroelectric, and intermediate phases and one that was developed as a room-temperature SmC* material for electro-optic applications. We report the field-induced temperature changes of these selected materials, measured indirectly using the Maxwell method. The maximum induced temperature change determined, 0.37 K, is currently record-breaking for an FLC and is sufficiently large to make these materials interesting candidates for the development for electrocaloric applications. Using the electrocaloric temperature change normalised as a function of electric field strength, as a function of merit, the performances of FLCs are compared with ferroelectric ceramics and polymers.

Temperature variability associations with cardiovascular and respiratory emergency department visits in Dhaka, Bangladesh.

Greenhouse gas emissions are changing the Earth's climate, most directly by modifying temperatures and temperature variability (TV). Residents of low- and middle-income countries (LMICs) are likely more adversely affected, due to lack of air conditioning to compensate. To date, there is no local epidemiological evidence documenting the cardio-respiratory health effects of TV in Dhaka, Bangladesh, one of the most climate change vulnerable cities in the world. We assessed short-term TV associations with daily cardiovascular disease (CVD) and respiratory emergency department (ED) visits, as well as effect modification by age and season. TV was calculated from the standard deviations of the daily minimum and maximum temperatures over exposure days. Time-series regression modeling was applied to daily ED visits for respiratory and CVD from January 2014 through December 2017. TV effect sizes were estimated after controlling for long-term trends and seasonality, day-of-week, holidays, and daily mean relative humidity and ambient temperature. A 1°C increase in TV was associated with a 1.00% (95%CI: 0.05%, 1.96%) increase in CVD ED visits at lag 0-1days (TV0-1) and a 2.77% (95%CI: 0.24%, 5.20%) increase in respiratory ED visits at lag 0-7days (TV0-7). TV-CVD associations were larger in the monsoon and cold seasons. Respiratory ED visit associations varied by age, with older adults more affected by the TV across all seasons. A 1°C increase in TV at lag 0-7days (TV0-7) was associated with a 7.45% (95%CI: 2.33%, 12.57%) increase in respiratory ED visits among patients above 50years of age. This study provided novel and important evidence that cardio-pulmonary health in Dhaka is adversely affected year-round by day-to-day increases in TV, especially among older adults. TV is a key factor that should be considered in evaluating the potential human health impacts of climate change induced temperature changes.

Experimental and computational model approach to assess the photothermal effects in transparent nanocrystalline yttria stabilized zirconia cranial implant

Background and objectiveIn the last few years, we have been exploring the use of transparent nanocrystalline yttria-stabilized zirconia (nc-YSZ) ceramics as a biomedical transparent cranial implant, referred as the “Window to the Brain” (WttB). The WttB aims at providing chronical optical access to the brain for diagnostics and therapeutic procedures and it has shown to provide an effective means to obtain enhanced results from optical imaging techniques. The objective of this work is to explore the photothermal effects of the Wttb produced when it is irradiated by a laser source. MethodsWe make experimental and computer models. The thermal effects of laser irradiation on the nc-YSZ samples were evaluated upon registering the induced temperature changes by means of thermal imaging. The computer models try to mimic the experimental models using a similar geometry, reproducing the physical situation by a couple thermal-optical problem and adjusting the main parameters from the experimental results. ResultsExperimental and computational coincides in results: Temperatures at the bottom surface of the implant does not exceed those which produce thermal damage. The quantitative comparison between experimental and computational models show that differences in results are under a reasonable value of 5% and qualitatively we observe a similar behavior. The results provide optimum values for the thermal-optical nc-YSZ parameters considering a linear and exponential relationship with temperature for the absorption coefficient: The thermal conductivity is k = 2.13 W/m·K and the absorption coefficient α varies from 426 to 526 m−1 with the linear relationship, and k = 2.04 W/m·K and α ∈ [433,502] m−1 with the exponential. The reflection coefficient is R = 19% in both cases. ConclusionsThe temperatures achieved in the nc-YSZ during the laser irradiation are suitable for biomedical applications. The combination of experimental and computational models contributes to build a clinically oriented model with the thermal-optical parameters values stablished and to determine their influence in results. Specifically, the absorption coefficient of the nc-YSZ samples is the most influent parameter in the obtained temperatures. Moreover, this combination provides a method to evaluate the relevant thermal-optical parameters of nc-YSZ samples obtained with different manufacturing processes.

Block copolymer self-assembly: Melt and solution by molecular density functional theory.

The self-assembly of block copolymer melts and solutions with two-dimensional density inhomogeneity is studied using modified inhomogeneous statistical associating fluid theory (iSAFT). A real-space combinatorial screening method under density functional theory formalism is proposed and used to map out the phase diagram of block copolymer melts including order-disorder transitions and order-order transitions. The predicted phase diagram agrees well with molecular dynamics simulation and self-consistent field theory. The compressibility effect on order-disorder transition temperature for block copolymer melts is modeled using iSAFT. The pressure induced temperature change by theory has a similar trend to experimental studies. Then, the lyotropic and thermotropic self-assembly phase behavior of block copolymer solutions is investigated. Detailed density distributions by iSAFT provide insight into the lyotropic properties of the block copolymer solutions at the molecular level. The effect of the block copolymer molecular architecture is studied by comparing block copolymers with different molecular packing parameters. Block copolymer solutions in the inverted hexagonal phase are predicted by theory for the block copolymer having a large molecular packing parameter. Finally, solvent selectivity is studied by modeling the block copolymers in a neutral good solvent. The enhanced local solvent concentration predicted by theory explains the reason for fewer ordered phases found in experiments.