Bath Temperature Research Articles

Gas Phase CO2 Photoreduction Behaviors over Composites of Galvanostatically Pulse‐Deposited Cu2O Nanoparticles and Anodized TiO2 Nanotube Arrays

Electrochemically synthesized composites of vertically aligned titanium dioxide (TiO2) nanotube arrays (TNAs) and cuprous oxide (Cu2O) nanoparticles (CNPs) are used for studying gas phase CO2 photoreduction behaviors. Anodized TNA surfaces with an average aperture size of 60 nm are decorated with CNPs using galvanostatic pulse electrodeposition. The nucleation and growth of CNPs are investigated with the help of cyclic voltammetry and potential‐time transients. The number of CNPs and their distribution on TNA surfaces are widely altered by adjusting the ON/OFF time, the number of applied current pulse, and the bath temperature. After characterizing structural and physical properties of the prepared CNPs/TNAs samples, in situ observation of CO2 photoreduction in gas phase over CNPs/TNAs is carried out in a high vacuum. The enhancement in CO2 photoreduction over CNPs/TNAs samples is observed for the optimized size and the number of CNPs on TNAs. The reaction route of the same is ascertained from the reaction products. The experimental results indicate that the size of CNPs should be comparable to the average pore size of TNAs for promoting CO2 photoreduction, and the relationship between CO2 photoreduction and the structural properties of CNPs is further discussed.

Visual liquefaction process of biomass pyrolysis vapors during indirect heat exchange: Experimental description, prediction, and verification

The present investigation proposed an experimental method combining bio-oil segmental recovery, vapor composition inversion, and function fitting, to describe the vapor evolution curves and heat maps of water, acetic acid, furfural, phenol, MCP, guaiacol and its derivatives in the indirect condensing field regulated by continuous water bath temperatures within 280–364 K. Under 280 K water bath, the recovery proportion of water exceeded 50 % after pyrolysis vapors moved 8 cm from inlet, and soon surpassed 90 % after 12.5 cm. At 337 K, 50 % recovery proportion of water required the vapors to move 20 cm, while guaiacol required only 10 cm for the same proportion. Half of the evolution description data were sampled and utilized to fit the prediction curves of vapor evolution with increasing bath temperature, and another half were used to verify these prediction curves. The overall prediction accuracy of the representative components remained at 70 %, despite the local accuracies less than 50 % within 280–300 K and 355–364 K. These findings provided a visual description and prediction method for the selective condensation of pyrolysis vapors. The cycle from research to application of selective condensation was effectively shortened by the prediction of vapor evolution under water bath based on sampling experiments.

Assessment of simultaneous removal of salt and dye by utilizing capacitive deionization and UV-electro oxidation hybrid process in saline wastewater treatment

In this research, the goal was simultaneous elimination of salt (NaCl) and dye (C·I Acid Orange 7 or AO7) through integration of capacitive deionization (CDI) technique with UV-based electrochemical advanced oxidation process (UV-EAOP). To optimize salt adsorption capacity (SAC) of MnO2 electrode, Taguchi's experimental design methodology was employed to fine-tune synthesis parameters, including bath temperature, current density, and precursor concentrations. BiOCl was synthesized and implemented as an anode to bolster AOP's effectiveness. Several experiments were conducted to analyze the effects of applying the combined AOP and CDI. The findings revealed that parameter optimization improved SAC, and the application of UV irradiation decreased electrode's SAC. Furthermore, it was observed that AO7 could enhance SAC while lowering salt adsorption rate (SAR). More importantly, the combined application of CDI and AOP resulted in superior pollutant removal efficiency and improved SAC, despite reduced SAR. Finally, color was entirely eliminated after 90 min, and the generated species were recognized by GC–MS. Additionally, a possible pathway for AO7 degradation was suggested based on the generated species.

Conditioned Pain Modulation Differences in Central and Peripheral Burning Mouth Syndrome (BMS) Patients.

To evaluate conditioned pain modulation (CPM) in burning mouth syndrome (BMS) patients with different pain mechanisms. Twenty BMS patients (52.0 ± 6.8 years, 17 women and 3 men) and age- and gender-matched 22 healthy controls were enrolled in this randomised controlled trial. The patients received an active lingual nerve block (lidocaine) and a placebo injection (saline) randomly with an interval of 1 week in a double-blinded manner. Patients evaluated their pain intensity on a 0- to 10-cm visual analogue scale (VAS) before and after each injection, with or without CPM. Based on the anaesthesia effect, BMS patients were divided into two groups with presumed different pain mechanisms; a 'central subgroup (n = 11)' with pain relief less than 1 cm and 'peripheral subgroup (n = 9)' with pain relief more than 1 cm on the VAS. Mechanical pain threshold (MPT) and wind-up ratio (WUR) were investigated at two oral mucosa regions: the region with most intense symptoms and a control region for the patient group; tongue and buccal region for the control group. CPM was induced by immersing the left hand into cold water. A moderate level of pain (around five on the VAS) was obtained by adjusting the water temperature. MPT and WUR were measured twice for all the participants with and without CPM, which was analysed and presented as relative change in MPT and WUR. Differences between groups were analysed using two-way ANOVA. Differences within group between tests were assessed by paired t-test. At baseline, there were no significant group differences for MPT or WUR between BMS patients and healthy controls (p ≥ 0.156). The mean bath temperature to evoke moderate pain for the BMS group was significantly lower than that for the healthy control group (8.9°C vs. 11.9°C, p = 0.003). The CPM evoked an inhibitory modulation in 18.2%-44.4% of BMS patients, while for the healthy group, the ratio was 68.2%-81.8%. Central BMS patients had smaller CPM effects than healthy participants at the painful site and control site, which indicated a decreased CPM function (p ≤ 0.034). Peripheral BMS patients had lower CPM effects than healthy participants only at the painful site (p = 0.037). The present findings documented impairment of central nociceptive inhibition processing in BMS patients which was more extensive in central BMS than peripheral BMS. These findings add to the suggestion that BMS may a heterogeneous pain condition with at least two different phenotypes.

Variations in the optical and thermoelectric behavior of ZnCo2O4 nanostructures as a function of synthesis temperature

Zinc cobalt oxide nanostructures were synthesized by electrochemical deposition of zinccobalt alloy at various bath temperatures (15, 30, 45 and 60 ˚C) and its hydrothermal oxidation at 100 ˚C. X-ray diffraction pattern and Raman spectroscopy data reveals the formation of spinal structure of ZnCo2O4. Photoluminescence spectra of the samples exhibit broad peaks with a red shift in the emission energy. Diffused reflectance spectroscopy measured the band gap of the synthesized materials; band gap is 3.06, 3.03, 3.02 and 2.99 eV, for samples electrodeposited at 15, 30, 45 and 60 ˚C, respectively. Optical conductivity of synthesized materials decreases with increasing deposition layers while reflectance shows opposite trend. Thermoelectric set up measures the change in potential difference through synthesized materials when different temperatures are applied and an increment in potential were observed. Seebeck co-efficient and power factor are also studied as function of bath temperature.

Eco-friendly utilization of microwaves for extraction of dye from logwood and Its application onto silk

For minimizing the pollution associated with synthetic colorants, the world again is going to realize the benefits of natural colorants in applied fields such as textiles, food flavors, etc. As part of the ongoing research project, hematein is being investigated as a potential natural colorant derived from logwood chips, and its implementation on silk fabric is being investigated under the effect of microwave radiations. A number of dyeing variables, including pH, dyeing duration, temperature of the dye bath, volume of extraction, and salt concentration, have been investigated, and the effect of isolation medium has also been evaluated. For new shades with improved fastness ratings, extracts of various sustainable bio-mordants and chemical mordant such as salts of aluminum and copper, and tannic acid were also used. An experiment revealed that treating un-irradiated silk with 40 mL of methanolic extract with a pH of 2, irradiated for 6 min, produced outstanding outcomes when dyed at 90°C for 60 min. The dyeing process included the addition of 9 g of salt per 100 mL of solution as an exhausting agent. In these circumstances, the utilization of sustainable mordants has not only enhanced the ratings of color fastness but has also rendered the procedure more environmentally friendly and less polluting. Therefore, microwave radiation has great potential for extracting colorants from plants and effectively applying them to natural materials under decreased conditions.

A temperature-sensitive metabolic valve and a transcriptional feedback loop drive rapid homeoviscous adaptation in Escherichia coli

All free-living microorganisms homeostatically maintain the fluidity of their membranes by adapting lipid composition to environmental temperatures. Here, we quantify enzymes and metabolic intermediates of the Escherichia coli fatty acid and phospholipid synthesis pathways, to describe how this organism measures temperature and restores optimal membrane fluidity within a single generation after a temperature shock. A first element of this regulatory system is a temperature-sensitive metabolic valve that allocates flux between the saturated and unsaturated fatty acid synthesis pathways via the branchpoint enzymes FabI and FabB. A second element is a transcription-based negative feedback loop that counteracts the temperature-sensitive valve. The combination of these elements accelerates membrane adaptation by causing a transient overshoot in the synthesis of saturated or unsaturated fatty acids following temperature shocks. This strategy is comparable to increasing the temperature of a water bath by adding water that is excessively hot rather than adding water at the desired temperature. These properties are captured in a mathematical model, which we use to show how hard-wired parameters calibrate the system to generate membrane compositions that maintain constant fluidity across temperatures. We hypothesize that core features of the E. coli system will prove to be ubiquitous features of homeoviscous adaptation systems.

A Study on the Physiological Diversity of Hand Bathing under Different Conditions

Achieving the best outcomes and ensuring patients are as comfortable as possible are crucial goals for healthcare professionals. Hospital stress has been linked to worsening patient outcomes and so it is important to implement methods for keeping patients calm. Targeting the autonomic nervous system through hand bathing could provide answers. Associate Professor Hajime Nakano and his collaborators at the Faculty of Nursing, Josai International University, Japan, used precise tools to measure the heart rates of patients bathing their hands in waterbaths maintained at carefully controlled temperatures. The researchers used a probe to non-invasively measure brain activation and found that hand bathing decreased sympathetic nervous system activity, increased parasympathetic nervous system activity and produced feelings of relaxation. Nakano and the team conducted another study in which they activated the sympathetic nervous system in volunteers with mental arithmetic and found that hand bathing significantly suppressed the activation. This led them to posit that thermal stimulation has the potential to impact the stress responses in patients and their motivation in a bidirectional manner, which indicated significant possibilities for clinical applications. The researchers are keen to explore how altering the temperature of the hand bath can positively impact patients and an optimum temperature be selected. The team wants to ensure that interventions are tailored to the unique needs of patients and, as such, observed responses under different conditions and collected vast data that has enabled them to consider a research design that accommodated individual differences.

The intracardiac echocardiographic findings during rewarming using catheter-based cryoablation

Abstract Introduction Cryoablation unlike radiofrequency ablation (RFA) does not damage the endothelium and lining and causes less physical damage, and the mechanisms remain unclear. The increased myocardial echogenicity (iME) observed by intracardiac echocardiography (ICE) during RFA has been reported as the ablation indicator. Purpose To evaluate the ICE findings during ablation using catheter-based cryoablation. Methods In an extra vivo experiment, we set the bovine myocardium to 36°C in a constant temperature bath and experimented on a water tank that generated a non-pulsatile flow. Catheter-based cryoablation was applied to the bovine myocardium at -80 degrees for 240 seconds. The ICE images were evaluated using ViewFlex Xtra during catheter-based cryoablation. Results Macroscopic change (Figure 1): Four seconds after the start of cooling, a thin film of ice began to form between the myocardium and the catheter, and after 7 seconds, the tip of the catheter was covered with ice and the surface of the myocardium was covered with ice. After that, it grew rapidly and an ice ball was formed. There was no change after 18 seconds of cooling. ICE findings (Figure 2): 4 seconds after cooling started, the ME around the catheter tip began to increase, and the ME gradually increased with flickering. The iME stopped after cooling down for 18 seconds and did not change after that. Immediately after stopping cooling, severe flickering occurred and the area of iME began to shrink. The ME gradually returned to its original state with slight bubbles from the central ablation site. Macroscopic change and ICE findings were reproducibly confirmed. Myocardial findings after ablation: The area of cooling was discernible, but the color difference from the surrounding area was not obvious. Conclusions The catheter-based cryoablation ablation shows the severest change detected by ICE immediately after stopping cooling. In addition to tissue damage during the freezing stage, the rewarming may be more associated with tissue damage.

The impedance drop early after energy delivery predicts steam pops during radiofrequency ablation

Abstract Background Steam pops during radiofrequency ablation (RFA) can cause serious complications. However, predictive factors for steam pops remain unclear. Purpose To investigate predictors for steam pops. Methods An in vitro experiment was performed using fresh bovine left ventricular myocardium. A myocardium cut into 4-5 cm slabs was fixed at the bottom of a constant temperature bath with temperature adjusted to 36.5 degrees Celsius, and a non-pulsatile flow rate of 5 L/min was generated. Using the catheter with a laser-cut 8Fr4.0mm flexible tip, RFA was applied at 30W, 60 seconds, perpendicular catheter placement to the tissue at various contact forces (5, 10, 20, 30, 40, 50g). A total of 138 lesions were created by applying RFA 23 times at each setting. Lesion depth and width were measured after RFA. Results Steam pops were observed in 49 of 138 lesions (36%). The higher impedance decrease in the first 5 seconds (-21.0±11.0Ω vs. -7.6±8.5Ω, P<0.0001), the larger impedance drop from initial to minimum impedance (if steam pop occurred, minimum impedance before steam pop was applied) (-28.9±13.0Ω vs. -13.1±12.9Ω, P<0.0001), higher initial impedance (132±48Ω vs. 87±38Ω, P<0.0001), power regulation by temperature control (44.9% vs 4.5%, P<0.0001), higher contact force (31.2±14.9g vs. 22.9±15.9g, P=0.0030), larger LSI (6.8±2.1 vs. 7.5±1.8, P=0.0037) were associated with steam pops. In multivariate analysis, the high impedance drops in the first 5 seconds (OR 2.0 for each 5Ω increase, 95%CI 1.0-1.3; P=0.033) and the power regulation by temperature control (OR 7.3, 95%CI 2.2-29.9; P=0.001) were independently related. In ROC curve analysis of the impedance drops in the first 5 seconds, an optimal cut-off value of steam pops was 8.0Ω (AUC 0.85, sensitivity 88%, specificity 73%) (figure 1). Steam pops were predicted with a sensitivity of 45% and specificity of 97% using both the impedance drop ≥ 8.0Ω in the first 5 seconds and power regulation by temperature control. Lesion depth and width were associated with total impedance reduction in lesions with an impedance drop < 8.0Ω during the first 5 seconds (R²=0.14, P=0.0012 with depth, R²=0.21, P<0.0001 with width), while were not associated with in lesions with an impedance drop ≥ 8.0Ω (figure 2). Conclusion The impedance drop early after RF energy delivery may predict steam pops during RFA.

Modeling Freeze‐Lining Formation: A Case Study in the Slag Fuming Process

Slag fuming (SF) is a metallurgical process designed to recycle Zn‐containing slags derived from various industrial residues. To protect the reactor from corrosive molten slag, a deliberate as‐solidified slag layer, known as a freeze lining (FL), is formed on the reactor walls using intense water‐cooled jackets. In this article, a computational‐fluid‐dynamics‐based model capable of simulating FL formation in a SF furnace is presented. To capture the complex multiphase flow dynamics, heat transfer, and FL formation during SF, a volume‐of‐fluid model is coupled with a mixture continuum solidification model. Three phases are considered: gas, liquid bulk slag, and solid slag (FL). Moreover, two types of FL are distinguished: one that solidifies on the reactor wall in the bulk slag region and another that solidifies on the reactor wall in the freeboard region owing to slag splashing. Comparisons between calculated FL thickness and heat fluxes and corresponding industrial data demonstrate satisfactory agreement. In this outcome, the robustness of the model is underscored and confidence in its accuracy is instilled. In the simulation results, valuable insights are provided into the evolution of the fuming process, particularly regarding the slag bath temperature, slag splashing dynamics, FL formation, local heat fluxes through the reactor wall, and global net energy balance.

Two-Staged Technology for CoCr Stent Production by SLM.

Additive manufacturing of porous materials with a specific macrostructure and tunable mechanical properties is a state-of-the-art area of material science. Additive technologies are widely used in industry due to numerous advantages, including automation, reproducibility, and freedom of design. Selective laser melting (SLM) is one of the advanced techniques among 3D fabrication methods. It is widely used to produce various medical implants and devices including stents. It should be noticed that there is a lack of information on its application in stent production. The paper presents the technological aspects of CoCr stent SLM fabrication, including design of stents and development of regimes for their manufacturing. Physical, chemical, and technological properties of CoCr powder were initially determined. Parametric design of mesh stent models was adopted. A two-stage approach was developed to ensure dimensional accuracy and quality of stents. The first stage involves a development of the single-track fusion process. The second stage includes the stent manufacturing according to determined technological regimes. The single-track fusion process was simulated to assign laser synthesis parameters for stent fabrication. Melting bath temperature and laser regimes providing such conditions were determined. Twenty-seven SLM manufacturing regimes were realized. Dependence of single-tracks width and height on the laser power, exposition time, and point distance was revealed. The qualitative characteristics of tracks imitating the geometry of the stent struts as well as favorable and unfavorable fusion regimes were determined. The results of surface roughness regulating of the stents' structural elements by various methods were analyzed. Thus, this two-staged approach can be considered as a fundamental approach for CoCr stent SLM fabrication.

Al Alloy Melting Behavior and Interfacial Reactions with Steel Under Natural Convection.

The Al alloy melting behavior and interfacial reactions during the steelmaking process of high-Al automotive steel were investigated in this study. The total dissolution time of Al bars (20 × 20 × 80 mm) in molten steel was quite short, decreasing from 21.4 s to 10.0 s with an increase in bath temperature from 1580 to 1620 °C. The Al alloy melting process at the molten steel temperature of 1600 °C included the formation of a solidified steel layer, the latter's rapid melting, and Al alloy normal melting, while at 1600 °C, the process included a second increase in the thickness of the solidified layer. Because steel elements such as [Fe], [C], [O], and [N] could diffuse during the whole Al alloy melting process, an Fe (Al)-FeAl-FeAl2-Fe2Al5-Al diffusion layer along the direction of the Al-rich matrix could be found at the Fe-Al interface. Moreover, FexO, Al2O3, and unstable AlN inclusions could be observed in the FeAl layer. This study also investigated how to reduce the number of these easily formed inclusions. Decreasing the pre-heating process time and dissolved oxygen content could be useful in decreasing FexO and Al2O3 inclusion formation. Some small-sized AlN inclusions formed in the center of the Al bars where they could not come into contact with the molten steel directly during the melting process; even for the immersion time of only 1 second, these inclusions were not stable in molten steel at the refining temperature and disappeared during the melting process.

Synergistic Dual Antibacterial Activity of Magnetite Hydrogels Doped with Silver.

In this work, we utilized poly-N-isopropylacrylamide (NIPAM), magnetic nanoparticles (MNPs), and silver nitrate to prepare magnetic hydrogel microparticles doped with silver, which exhibited a dual antimicrobial effect. The antibacterial effect of these composites was mediated by the antimicrobial activity of silver and the magnetic hyperthermic induction, which we believe increased biofilm disruption and silver release into the surrounding bacterial biofilms. The prepared particles were characterized by using several analytical techniques. The particles exhibited a porous morphology impregnated evenly with silver nanoparticles, as observed by scanning electron microscopy (SEM). Furthermore, we examined the antibacterial activity of our microparticles against Escherichia coli by determining the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). Our findings revealed that the composites demonstrated significant antibacterial activity of up to 81% under magnetic hyperthermia as compared to 45% when samples were heated to the same temperature in a water bath at constant silver concentration. This demonstrates the distinctive inhibitory features of MNPs in enhancing bacterial killing when a magnetic field is applied. The findings of this study lay the groundwork for further exploration of microparticle-based antimicrobial therapies, which can contribute to the development of more advanced wound healing devices and better sterilization methods for medical devices.

Investigating the impact of coagulation bath temperature on the properties of biphasic calcium phosphate/poly(vinylidene fluoride)‐based membrane scaffold via immersion precipitation

AbstractIn this study, composite membrane scaffolds comprising poly(vinylidene fluoride) (PVDF) and boron‐containing biphasic calcium phosphate (BCP) are developed using a non‐solvent‐induced phase separation technique at coagulation bath temperatures of −5, 0, 10, and 20 °C. The morphology, pore size and tensile strength of the scaffolds are primarily influenced by the bath temperature. Moreover, raising the bath temperature enhances the thermal properties and β‐crystalline phase fraction. Results demonstrate that changes in the temperature increase the surface hydrophilicity and reduce the degree of swelling. According to the in vitro bioactivity analysis, apatite growth is affected by the interactive relation between the surface of the samples and the simulated body fluid (SBF) medium, in addition to the superior bioactivity of the scaffolds. In vitro cytotoxicity assay results confirm the extensive spreading of L‐929 cells on the sample surfaces, indicating the high biocompatibility of the scaffolds. Based on these favorable properties, the novel composite membranes produced, particularly at 20 °C coagulation bath temperature, may contribute to applications in bone tissue engineering.

Dephasing dynamics of a central spin interacting with a classical Ising spin bath

We study the effect of interaction between bath spins on central spin dynamics. For this end, we consider various types of interactions among the bath fluctuators. We give an analytical relation for the dephasing dynamics of a central spin homogeneously interacting with a bath of classically interacting spins in thermal equilibrium. The obtained exact relation for the central spin dynamics depends on the average of the number of bath spins N in the canonical ensemble. We find the relation of dephasing time with bath's temperature and strength of interaction between bath spins. We show that if the classically interacting bath is large enough, off-diagonal coherence will decay into Gaussian form. This Gaussian decay is valid for temperatures higher than critical temperature. Moreover, we analytically prove the equivalence of dephasing dynamics for central spin models with classical Ising spin bath and quantum flip-flop spin bath interactions. Therefore, the dephasing dynamics for central spin models with quantum spin bath interactions can be reproduced with much less expensive classical spin bath interaction model instead. Our results can be applied in a number of quantum systems used in quantum sensing such as color centers in solids or quantum dots manuscript.

Application of DPG/KH550 modified pyrolysis carbon black in oil and high temperature‐resistant NBR composites

AbstractIn this paper, pyrolysis carbon black (CBp) was introduced into nitrile butadiene rubber (NBR), the effects of the ratio of CBp and carbon black (N326) on the properties of NBR composites were investigated, and the optimal ratio was determined. On this basis, the accelerator DPG, coupling agent KH550 and CBp were modified by ball milling and plasma. The results showed that when the ratio of CBp to N326 was 40:15, the overall properties of NBR composites was better. Compared with the unmodified CBp/NBR composites, the change rate of tensile product, resilience and DIN abrasion of ball milling‐plasma modified CBp/NBR composites in oil environment were reduced by 52.96%, 12.81%, and 27.19%, respectively, and the tear strength after double damage by high temperature and oil bath was increased by 15.63%, which resulted in better oil and high temperature‐resistance. In summary, the ball milling‐plasma combined with DPG/KH550 modified CBp can not only replace N326 carbon black, but also realize the preparation of NBR composites with better oil and high temperature‐resistance.

Comparison of Hardness by Electrolytic and Electroless Deposition of Nickel on Aluminium

Abstract The work deals with the hardness characteristic of substrates coated with nickel through two primary methods: electrolytic deposition and electroless Ni-P deposition. The optimised process parameters for both the process was determined by varying a particular parameter keeping the rest constant in order to obtain minimum crystallite size of Ni. The size of the crystallite were determined using Scherrer’s equation. The optimized combination of process parameter for electrolytic deposition is: 270gm/lt of Nickel Sulfate, 60gm/lt Nickel Chloride, 35gm/lt Boric Acid, current density of 90mA/cm2 bath temperature of 55°C. The optimized combination of process parameter for electroless Ni-P deposition: 34gm/lt Nickel Sulfate, 23 gm/lt Sodium Hypophosphite, 46 gm/lt of Lactic acid, 42 gm/lt of Sodium Citrate, pH 5.0 and bath temperature 85°C. The optimised deposition rate 22μm/hr. Micro-hardness (Vickers) tests were conducted on the coated samples with a 50 gf load. The cause for difference in hardness was due to buildup of residual stress during deposition of Nickel on the substrate(aluminium). The orientation and surface texture of the materials are determined.

Full inverse Compton Scattering: Total transfer of energy and momentum from electrons to photons

In this article we discuss a peculiar regime of Compton Scattering that assures the maximum transfer of energy and momentum from free electrons propagating in vacuum to the scattered photons. We name this regime Full Inverse Compton Scattering (FICS) because it is characterized by the maximum and full energy loss of the electrons in collision with photons: up to 100% of the electron kinetic energy is indeed transferred to the photon. In the case of relativistic electrons, characterized by a large Lorentz factor (γ≫1), FICS regime corresponds to an incident photon energy equal to mec22, i.e. approximately 255.5 keV. We interpret such an astonishing result as FICS being the time reversal of direct Compton Scattering of very energetic photons (of energy much greater than mec2) onto atomic electrons. Although the cross section of Compton scattering is decreasing with the energy of the incident photon, making the process less probable with respect to other reactions (pair production, nuclear reactions, etc.) when high energetic photons are bombarding a target, the kinematics straightforwardly implies that the back-scattered photons would have an energy reaching asymptotically mec22. FICS is instead the unique suitable working point in Compton scattering for achieving the total transfer of (kinetic) energy exactly from the electron to the photon. Experiencing transitions from the initial momentum to zero in the laboratory system, in FICS the electron is also subject to very large negative acceleration; this fact can lead to possible experiments of sensing the Unruh temperature and related photon bath. On the other side of the energy dynamic range, low relativistic electrons can be completely stopped by moderate energy photons (tens of keV), leading to full exchange of temperature between electron clouds and photon baths. Cosmic gamma ray sources can be affected in their evolution by this peculiar FICS regime of Compton scattering.

Effect of bath temperature on corrosion resistance of electroless Ni-P coating on 5A90 Al-Li alloy

Abstract The Al-Li alloy exhibits outstanding characteristics, including remarkable specific strength, elevated specific stiffness, and heightened susceptibility to localized corrosion. Electroless Ni-P coating is extensively applied over the appearance of aluminum alloys to enhance their corrosion resistance. Electroless Ni-P coating was applied to 5A90 Al-Li alloy at various plating temperatures for the study presented in this publication. The coating’s surface, composition, and cross-sectional morphology were examined using SEM/EDS. The corrosion behavior of coating was studied using the potentiodynamic polarization curve. Results showed that coating on the surface of 5A90 Al-Li alloy was uniform and smooth. Ni and P elements were evenly distributed in the coating. The thickness of coatings at 80°C, 85°C, 90°C and 95°C was about 3.98 μm, 5.5 μm, 11.2 μm, and 10.29 μm, respectively. As the temperature of the bath increased, the corrosion resistance of the coating first increased and afterward decreased. The corrosion resistance of the coating might be correlated with its thickness.