Hot Bath Research Articles

Changes in sleep profile on exposure to sodium chloride and artificially carbonated springs: a pilot study.

[Purpose] Herein, we aimed to investigate the effects of bathing in a sodium chloride spring and an artificially carbonated spring on core body temperature and electroencephalograms, to assess whether the springs facilitate sleep. [Participants and Methods] This randomized, controlled, crossover study evaluated the effects of a sodium chloride spring, an artificially carbonated spring, a plain hot bath, and no bath on sleep. The subjective evaluations and recording of temperature were performed before/after bathing at 40 °C for 15 min at 22:00 h, before nocturnal sleep (0:00-7:00 h), and after the participants (n=8) woke up in the morning. [Results] Bathing significantly increased the core body temperature, with significant subsequent declines observed until bedtime. Participants in the sodium chloride spring group had the highest average core body temperature, while participants in the no-bath group had the lowest average core body temperature before bedtime (23:00-0:00 h). During bedtime (1:00-2:00 h), the participants in the no bath group had the highest average core body temperature, while participants in the artificially carbonated spring group had the lowest average core body temperature. The amount of delta power/min in the first sleep cycle significantly increased in the bathing groups, with the highest value during bedtime being recorded in the artificially carbonated spring group, followed by the sodium chloride spring, plain hot bath, and no-bath groups. These sleep changes were associated with significant declines in the elevated core body temperature. Increased heat dissipation and decreased core body temperature were observed in the artificially carbonated spring and sodium chloride spring groups, which increased the delta power during the first sleep cycle compared with that observed in the plain hot bath group, followed by the no-bath group. [Conclusion] An artificially carbonated spring would be the most appropriate given each circumstance because it did not cause fatigue, as observed with the sodium chloride spring.

Enhancing heat transfer performance of automotive radiator with H2O / activated carbon nanofluids

The deionized (DI) water and activated carbon (AC) nanofluids were produced at different volume concentrations (VCs) such as 0.1, 0.25, and 0.4 %. ACNMs were produced through the pyrolysis process of deadly available Kigelia Africana leaves in a muffle oven at 500 °C. The structural properties of the activated carbon nanomaterials (ACNMs) were described through the usage of SEM, EDS, XRD, and FTIR analyzers. Thermal exchange properties that as density (ρ), thermal conductivity (TC), specific heat (SH), and viscosity (µ) of DI water - AC-based nanofluids were evaluated experimentally. The five various mass flow rates (MFRs) namely 20, 40, 60, 80, and 100 g/sec were applied with different VCs of DI water - AC nanofluids in this study. In addition, the hot fluid (nanofluid) inlet temperature was constantly maintained with the help of a hot DI water bath at 50, 60, and 70 °C, respectively. The highest thermal conductivity (TC) augmentation attains up to 9.134 % is detected at 0.4 vol% of ACNMs loading at 70 °C. The addition of ACNMs augments the specific heat (SH) of the nanofluids substantially, and this augmentation diminutions with an increase in the ACNMs concentration. The addition of ACNMs in the DI water augments the Nusselt number by 21.76 %, 24.71 %, and 32.47 % for 50, 60, and 70 °C respectively, at a VCs of 0.4 % and mass flow rate of 0.1 kg/sec in the car radiator. In addition, turn up a palpable reduction in Reynolds number for specified MFRs for all the ACNM nanofluids.

Immobilization of Strontium Aluminate into Recycled Polycarbonate Plastics towards an Afterglow and Photochromic Smart Window.

A transparent smart window made of recycled polycarbonate plastic (PCP) waste was prepared and immobilized with strontium aluminate phosphor nanoparticles (SAPN). It has afterglow emission, super-hydrophobicity, durability, photostability, good mechanical properties, ultraviolet protection, and high optical transmittance. To create an afterglow emission polycarbonate smart window (SAPN@PCP), recycled polycarbonate waste was integrated with various concentrations of SAPN (15-52 nm). SAP micro-scale powder was made using the solid-state high temperature method. The SAP nanoparticles were produced using the top-down method. To create a colorless plastic bulk, recycled polycarbonate waste was inserted into a hot bath. This colorless plastic was thoroughly combined with SAPN and cast to create an afterglow luminous smart window. To investigate its photoluminescence properties, spectrum profiles of excitation and emission were measured. According to the luminescence parameters, the phosphorescent colorless polycarbonate plates displayed a change in color to strong green under UV illumination and greenish-yellow in a dark box. The afterglow polycarbonate smart window displayed two emission peaks at 496 and 526 nm, and an absorption wavelength of 373 nm. Upon increasing the SAPN ratio, the hydrophobic activity, hardness, photostability, and UV protection were improved. Luminescent polycarbonate substrates with lower SAPN ratio demonstrated rapid and reversible fluorescence under UV light, while the higher SAPN content in the luminous polycarbonate substrates showed afterglow.

Fabrication of Compliant and Transparent Hollow Cerebral Vascular Phantoms for In Vitro Studies Using 3D Printing and Spin-Dip Coating.

Endovascular surgery through flow diverters and coils is increasingly used for the minimally invasive treatment of intracranial aneurysms. To study the effectiveness of these devices, in vitro tests are performed in which synthetic vascular phantoms are typically used to reproduce in vivo conditions. In this paper, we propose a manufacturing process to obtain compliant and transparent hollow vessel replicas to assess the mechanical behaviour of endovascular devices and perform flow measurements. The vessel models were obtained in three main steps. First, a mould was 3D-printed in a water-soluble material; two techniques, fusion deposition modelling and stereolithography, were compared for this purpose. Then, the mould was covered with a thin layer of silicone through spin-dip coating, and finally, when the silicone layer solidified, it was dissolved in a hot water bath. The final models were tested in terms of the quality of the final results, the mechanical properties of the silicone, thickness uniformity, and transparency properties. The proposed approach makes it possible to produce models of different sizes and complexity whose transparency and mechanical properties are suitable for in vitro experiments. Its applicability is demonstrated through idealised and patient-specific cases.

Historical issues of hydrotherapy in thermal–mineral springs of the Hellenic world

Many springs have been recorded in Greece; some of them are characterized as thermo-mineral springs and are associated with their position between Eurasia and Africa, the volcanic activity, and the presence of tectonic faults. The therapeutic use of water (hydrotherapy) has been recorded in ancient Greece since at least 1000 BC. Asclepius was the god of medicine in ancient Greek religion and priests operated his worship centers (Asclepieia) offering medical services in areas with proper climatic conditions. In historical times, Hippocrates from the Aegean island of Kos (460–375 BC) is considered the father of scientific medicine as well as hydrotherapy. During the Hellenistic period, the significance of water in health was widely recognized. In the Roman era, many doctors evolved hydrotherapy treatment and the use of hot baths continued in the early Byzantine period until the sixth century AD. Finally, during the Ottoman period, the kind of respiratory bath, named Hamam, was the dominant form in public baths. Their temperature ranges between 20.5 and 83 °C, and the dominant hydrochemical type is Na-Cl. This review describes the history of hydrotherapy in Greece through the centuries, the physicochemical characteristics of thermal springs, as well as contemporary and future trends and challenges are presented.

Polymer-chain configurations in active and passive baths.

The configurations taken by polymers embedded in out-of-equilibrium baths may have broad implications in a variety of biological systems. As such, they have attracted considerable interest, particularly in simulation studies. Here we analyze the distribution of configurations taken by a passive flexible chain in a bath of hard, self-propelled, vibrated disks and systematically compare it to that of the same flexible chain in a bath of hard, thermal-like, vibrated disks. We demonstrate experimentally that the mean length and mean radius of gyration of both chains agree with Flory's law. However, the Kuhn length associated with the number of correlated monomers is smaller in the case of the active bath, corresponding to a higher effective temperature. Importantly, the active bath does not just simply map on a hot equilibrium bath. Close examination of the chains' configurations indicates a marked bias, with the chain in the active bath more likely assuming configurations with a single prominent bend.

Association between habitual hot spring bathing and depression in Japanese older adults: A retrospective study in Beppu

ObjectivesThermal therapy is used to manage various psychological diseases, such as depression. We investigated the relationship between hot spring bathing and depression in older adults using questionnaire responses. Design and SettingWe comprehensively evaluated the preventive effects of long-term hot spring bathing in 10429 adults aged ≥ 65 years in Beppu, Japan, by conducting a questionnaire study on the prevalence of depression (n = 219). Main outcome measuresOdds ratios (ORs) with 95% confidence intervals (CIs) were calculated using a multivariable logistic regression model for history of depression. ResultsA separate multivariable logistic regression model for inference showed that female sex (OR, 1.56; 95 % CI, 1.17–2.08; p = 0.002), arrhythmia (OR, 1.73; 95 % CI, 1.18–2.52; p = 0.004), hyperlipidemia (OR, 1.63; 95 % CI, 1.14–2.32; p = 0.006), renal disease (OR, 2.26; 95 % CI, 1.36–3.75; p = 0.001), collagen disease (OR, 2.72; 95 % CI, 1.48–5.02; p = 0.001), allergy (OR, 1.97; 95 % CI, 1.27–3.04; p = 0.002), and habitual daily hot spring bathing (OR, 0.63; 95 % CI, 0.41–0.94; p = 0.027) were independently significantly associated with a history of depression. ConclusionsWe found an inverse relationship between habitual daily hot spring bathing and history of depression. Prospective randomized controlled trials on habitual daily hot spring bathing as a treatment for depression are warranted to investigate whether the use of hot springs can provide relief to those with psychiatric and mental health disorders.

The Role of the Tourism Office in Improving the Community's Economy at the Tourism Object in Pasaman Regency

The main problem in this study is the lack of awareness on the management of the rimbo orphanage nature reserve tourism, so that it has an impact on the economic income of the community which is getting less and less to anticipate this problem, the important role of the local government. The purpose of this study is to find out the potential that exists in tourist objects, to find out the empowerment carried out in reviving tourism objects, and to find out the empowerment carried out by the community in promoting the Rimbo Panti Nature Reserve Tourism Object in Kecamatan Panti , Kabupaten Pasaman. The type of research used is field research with qualitative methods and descriptive approaches. Data collection techniques are observation, interviews, and documentation. The data analysis technique used by the researcher is data reduction, data presentation and conclusion drawing. The guarantor of the validity of the data in this study uses source triangulation, technique triangulation and time triangulation. Based on the research conducted, it was found that the potential that exists in the Rimbo Panti Nature Reserve Tourism Object is hot springs, hot baths and the latest specific drink, namely Roasted Coffee. Empowerment was carried out to revive Rimbo Panti through improving infrastructure and also maintaining the beauty of the flora and fauna of the Rimbo Panti Nature Reserve Tourism Object, but this has not been carried out properly due to Covid-19 so that the empowerment program has not been implemented optimally. Meanwhile, the empowerment carried out by the community to promote the Rimbo Panti Nature Reserve Tourism Object through social media, electronic media and has also been broadcast on TVRI Padang.

Current Situation, Challenges and Prospects of Geothermal Energy Development in China

Based on the geothermal resource conditions, the current situation of China's geothermal energy utilization in heating (cooling), power generation, hot spring bathing, high-end seed breeding, and hot dry rock exploration and development are explained. The development trend of geothermal energy in the fields of resource discovery, exploration, development and utilization technology, utilization scale, macro policies, and market participants are predicted in the context of the goal of "carbon peak and carbon neutral". Finally, suggestions on the management of China's geothermal industry is proposed.

Gravity as a portal to reheating, leptogenesis and dark matter

We show that a minimal scenario, utilizing only the graviton as an intermediate messenger between the inflaton, the dark sector and the Standard Model (SM), is able to generate simultaneously the observed relic density of dark matter (DM), the baryon asymmetry through leptogenesis, as well as a sufficiently hot thermal bath after inflation. We assume an inflaton potential of the form V(ϕ) ∝ ϕk about the minimum at the end of inflation. The possibility of reheating via minimal gravitational interactions has been excluded by constraints on dark radiation for excessive gravitational waves produced from inflation. We thus extend the minimal model in several ways: i) we consider non-minimal gravitational couplings — this points to the parameter range of DM masses {M}_{N_1} ≃ 2–10 PeV, and right-handed neutrino masses {M}_{N_2} ≃ (5–20) × 1011 GeV, and TRH ≲ 3 × 105 GeV (for k ≤ 20); ii) we propose an explanation for the PeV excess observed by IceCube when the DM has a direct but small Yukawa coupling to the SM; and iii) we also propose a novel scenario, where the gravitational production of DM is a two-step process, first through the production of two scalars, which then decay to fermionic DM final states. In this case, the absence of a helicity suppression enhances the production of DM and baryon asymmetry, and allows a great range for the parameters including a dark matter mass below an MeV where dark matter warmness can be observable by cosmic 21-cm lines, even when gravitational interactions are responsible for reheating. We also show that detectable primordial gravitational wave signals provide the opportunity to probe this scenario for TRH ≲ 5 × 106 GeV in future experiments, such as BBO, DECIGO, CE and ET.

Vacuum-Sealed Hot Water Bath Immersion for the Preparation of Anatomical and Surgical Cadaveric Bone Models

Bone models serve many purposes, including improving anatomical understanding, preoperative surgical planning, and intraoperative referencing. Several techniques for the maceration of soft tissues have been described, mainly for forensic analysis. For clinical research and medical use, these methods have been superseded by three-dimensional (3D) printed models, which require substantial equipment and expertise, and are costly. Here, cadaveric sheep vertebral bone was cleaned by vacuum sealing the specimen with commercial dishwashing detergent, immersing in a hot water bath, and subsequently manually removing the soft tissue. This eliminated the disadvantages of the previously existing maceration methods, such as the existence of foul odors, usage of hazardous chemicals, substantial equipment, and high costs. The described technique produced clean, dry samples while maintaining anatomical detail and structure to accurately model the osseous structures that can be useful for preoperative planning and intraoperative referencing. The method is simple, low-cost, and effective for bone model preparation for education and surgical planning in veterinary and human medicine.

Optimization for Green Path in Wood Extractives by Taguchi Analysis

Extractive composition of Pinus pinaster (Maritime pine) wood was studied with choline chloride based deep eutectic solvents (DES). Two different eutectic mixtures (ChCl: Et-Gly; ChCl:Urea 1:2 molar ratio), two different extraction methods (hot water bath, ultrasound assisted extraction), and temperature (40 – 60 °C), time (30 – 60 min.) and solid:liquid ratio (1:10 – 1:20 g/mL) parameters were applied. For the optimization of operation conditions, Taguchi analysis was performed. Resin acids formed the chemical composition of Pinus pinaster (Maritime pine) wood. Dehydroabietic acid, abietic acid and isopimaric acid were found to be the major compounds. The impact of parameters on the performance of the system was determined as follows: DES type > solid:liquid ratio > extraction method > temperature > time. So, for the extraction of lipophilic compounds in Maritime pine wood, the optimum conditions were determined as hot water bath extraction at 60 °C with ethylene glycol and 1:10 solid liquid ratio for 60 min.

Hot spring bathing is associated with a lower prevalence of hypertension among Japanese older adults: a cross-sectional study in Beppu

Hot spring bathing is practiced to help manage various diseases, including hypertension. We investigated the preventive effects on hypertension of hot spring bathing among older adults in a data analysis using responses to a previous questionnaire with the aim to identify a novel approach in the prevention and management of hypertension. Among 10,428 adults aged ≥ 65 years, we assessed the hot spring bathing habits of 4001 individuals with a history of hypertension. We calculated odds ratios (OR) with 95% confidence intervals using a multivariable logistic regression model for history of hypertension. In multivariable logistic regression, age (≥ 85 years: OR, 1.410); history of arrythmia (OR, 1.580), stroke (OR, 1.590), gout (OR, 1.880), diabetes mellitus (OR, 1.470), hyperlipidemia (OR, 1.680), renal disease (OR, 1.520), chronic hepatitis (OR, 0.648); and hot spring bathing at 19:00 or later (OR, 0.850) were independently and significantly associated with hypertension during the lifetime. We found an inverse relationship between habitual nighttime hot spring bathing and a history of hypertension. Prospective randomized controlled trials on nighttime hot spring bathing as a treatment for hypertension are warranted to investigate whether nighttime hot spring bathing can help in preventing hypertension among adults aged ≥ 65 years.

Curvature and van der Waals interface effects on thermal transport in carbon nanotube bundles

A van der Waals (vdW) heterostructure, can be used in efficient heat management, due to its promising anisotropic thermal transport feature, with high heat conductance in one direction and low conductance in the rest. A carbon nanotube (CNT) bundle, can be used as one of the most feasible vdW heterostructures in a wide range of nanoscale devices. However, detailed investigations of heat transport in CNT bundles are still lacking. In this paper, we study heat transport in different CNT bundles—homogeneous bundles consisting of the one CNT radius (curvature) and inhomogeneous bundles constructed from different CNTs with different curvatures. We also investigate the comparison between two possible thermostatting configurations: the two ends connected (TEC) case in which there is at least a direct covalently connected path between the hot and cold heat baths, and the one end connected (OEC) case in which the system can be divided at least into two parts, by a vdW interacting interface. Nonequilibrium molecular dynamics simulations have been carried out for a wide range of configurations and curvature differences. We find that, in homogeneous bundles, by increasing the number of outer CNTs, the heat conductance increases. In inhomogeneous bundles, the total heat flux shows dependence on the difference between the curvature of the core and outer CNTs. The less the difference between the curvature of the core and the outer CNTs, the more the thermal conductance in the system. By investigating the spectral heat conductance (SHC) in the system, we found that a larger curvature difference between the core and outer CNTs leads to a considerable decrease in the contribution of 0–10 THz phonons in the bundled zone. These results provide an insightful understanding of the heat transport mechanism in vdW nano-heterostructures, more important for designing nanoelectronic devices as well as systems in which asymmetry plays a significant role.

Performance optimization on finite-time quantum Carnot engines and refrigerators based on spin-1/2 systems driven by a squeezed reservoir

We investigate the finite-time performance of a quantum endoreversible Carnot engine cycle and its inverse operation — Carnot refrigeration cycle, employing a spin-1/2 system as the working substance. The thermal machine is alternatively driven by a hot boson bath of inverse temperature β h and a cold boson bath at inverse temperature β c (>β h). While for the engine model the hot bath is constructed to be squeezed, in the refrigeration cycle the cold bath is established to be squeezed, with squeezing parameter r. We obtain the analytical expressions for both efficiency and power in heat engines and for coefficient of performance and cooling rate in refrigerators. We find that, in the high-temperature limit, the efficiency at maximum power is bounded by the analytical value , and the coefficient of performance at the maximum figure of merit is limited by , where η C = 1 – β h/β c and ε C = β h/(β c – β h) are the respective Carnot values of the engines and refrigerators. These analytical results are identical to those obtained from the Carnot engines based on harmonic systems, indicating that the efficiency at maximum power and coefficient at maximum figure of merit are independent of the working substance.

Effect of Temperature on Rehydration of Cornelian Cherry Fruit: A Kinetics Study

Cornelian cherry is an important resource for human health and nutrition. Cornelian cherry is very rich in contains many mineral substances such as vitamin C. For this reason, it is important that cornelian cherry can be dried and used later. This was studied investigated the rehydration capacity and the kinetics of dried cornelian cherry fruit under certain conditions. Drying was carried out in a thin layer using a convective dryer. The drying conditions were determined as the different temperatures of air (50, 60, and 70°C) and the constant velocity of air of 1 m/s. The rehydration experiments of dried cornelian cherry were actualized in a hot water bath with a water circulator. The experiments were made with rehydration water temperatures of 25, 50, and 75°C. The rehydration characterization of dried cornelian cherry was evaluated in terms of rehydration curves, rehydration rate curves, final moisture content, and rehydration coefficient (COR). Fick’s 2nd law was employed to determine the coefficients of effective diffusivity of the rehydration process. The kinetics models of Peleg, the Weibull, the first-order, and the exponential were used to determine the kinetics of rehydration. The model of Weibull was determined to be the most suitable model for investigating the kinetics of rehydration of cornelian cherry samples. The Model fit was evaluated by considering statistical parameters such as R2, χ2, RMSE, and P%. In addition, the energy of activation of rehydration was figured with the rate constants of the most suitable models.

Itchy Red-Brown Spots on a Child.

A 5-year-old boy presented with red-brown spots diffusely spread over the body that were present since birth. There were no subjective symptoms, except for rare instances of flushing, itching, and urtication following hot baths and abrasive scrubs.

Thermal pretreatment of Lantana camara for improved biogas production: Process parameter studies for energy evaluation

The rigid lignocellulosic structure of Lantana camara impedes the hydrolysis phase and reduces the biogas production during anaerobic digestion of Lantana camara. Hence, the current study focuses on the impact of various heating pretreatment techniques, viz., hot air oven (HAO), autoclave (ATC), hot water bath (HWB), and microwave (MCW) on L. camara to speed up hydrolysis and boost up biogas production. ATC pretreatment of L. camara was witnessed to be most efficient compared to HAO, MCW, and HWB pretreatment. ATC pretreatment enhanced the solubilization (45.44%), and an increment in volatile fatty acids (VFA) was observed (56.75%) at 110 °C for 80 min when correlated to the untreated (control). Cumulative methane production following ATC pretreatment had risen to 3656 mL in 5 weeks from 2895 mL in 7 weeks. Thermal pretreatment of Lantana camara broke down the rigid lignocellulosic structure, accelerating the hydrolysis stage and improving biogas production simultaneously. To the best of our knowledge, this is the first thermal pretreatment study conducted on Lantana camara for biogas production.

Dynamical control of quantum heat engines using exceptional points

A quantum thermal machine is an open quantum system coupled to hot and cold thermal baths. Thus, its dynamics can be well understood using the concepts and tools from non-Hermitian quantum systems. A hallmark of non-Hermiticity is the existence of exceptional points where the eigenvalues of a non-Hermitian Hamiltonian or a Liouvillian superoperator and their associated eigenvectors coalesce. Here, we report the experimental realization of a single-ion heat engine and demonstrate the effect of Liouvillian exceptional points on the dynamics and the performance of a quantum heat engine. Our experiments have revealed that operating the engine in the exact- and broken-phases, separated by a Liouvillian exceptional point, respectively during the isochoric heating and cooling strokes of an Otto cycle produces more work and output power and achieves higher efficiency than executing the Otto cycle completely in the exact phase where the system has an oscillatory dynamics and higher coherence. This result opens interesting possibilities for the control of quantum heat engines and will be of interest to other research areas that are concerned with the role of coherence and exceptional points in quantum processes and in work extraction by thermal machines.

Effect of extraction parameters on the yield and quality of pectin from mango (Mangifera indica L.) peels

Pectin is an essential polysaccharide that is normally found in the peels of various fruits and vegetables. It acts as a gelling agent and stabilizer in many foods and pharmaceutical industries. The current study was focused on the potential of mango peel as a source of pectin. The pectin was isolated from mango (Mangifera Indica) peels powder in the hot water bath at five different extraction conditions viz. temperatures (60, 70, 80, 90 and 100 °C), pH (1.0, 1.5, 2.0, 2.5 and 3.0) and time (60, 80, 100, 120 and 140 min). At different extraction conditions, the yield of pectin ranged between 14.60 and 28.42%. The highest yield condition was achieved (28.06%, 28.42% and 28.06%) at the temperature of 90 °C, 1.5 pH, and the extraction time of 120 min. The quality parameters of pectin such as equivalent weight (450.45 to 1324.24 g), methoxyl content (5.15 to 7.90%), anhydrouronic acid content (48.93 to 74.62%), and degree of esterification (43.28% to 77.14%), were found in satisfactory level. In contrast, the soluble sugar content was higher (12.43 to 23.49%), the anhydrouronic acid (AUA) content was low as compared to the existing data for various pectin sources. This is an indication of the existence of protein in the extracted pectin. The mango peel powder was applied in the jelly formulation at different concentrations (0.5%, 1.0%, and 1.5%) to identify the quality and the sensory characteristics. The sensory attributes (e.g., color, taste, appearance and flavor) was highly appreciable at 1% pectin concentration compared to other concentration of pectin. The created polynomial model efficiently accounted for the data fluctuation and accurately captured the actual correlation between the independent and dependent variables. The extraction temperature, pH, and time had a substantial impact on the yield and quality of the extracted pectin, according to the results of both single factor studies and RSM. The optimal conditions were determined from the optimization research to be 88.86 °C, pH 1.36, and 79.61 min, which produced 23.31% pectin. Lastly, the manufacturer will be able to get information regarding the quality of mango peel pectin. It can be utilized as an important source of pectin for application in food and pharmaceutical industries.