Clinical Observation of the Hot and Humid Compress Therapy of Traditional Chinese Medicine in the Treatment of Qi Stagnation and Blood Stasis Type of Lumbar Disc Herniation

Background: Although a number of studies have reported that the hot and humid compress from traditional Chinese medicine (TCM) is effective in treating lumbar disc herniation (LDH) with qi stagnation and blood stasis, clinical evidence is limited. Objective: The purpose of this study is to provide high-quality evidence to support the effectiveness of the traditional Chinese hot and humid compress in the treatment of LDH with qi stagnation and blood stasis. Methods: From October 2021 to November 2023, 86 patients with LDH of qi stagnation and blood stasis type were recruited in our hospital and divided into a control (n = 43) and an observation group (n = 43) according to the random number table method. The control group was given routine clinical treatment, and the observation group was treated with the hot and humid compress therapy for two weeks. The visual analogue scale (VAS) score, Japanese Orthopaedic Association (JOA) score, TCM syndrome score, serum interleukin-6 (IL-6), serum interleukin-1β (IL-1β), and tumor necrosis factor-α (TNF-α) were observed and compared between the two groups before and after treatment, and the clinical efficacy of the two groups was evaluated. Results: After treatment, the VAS score, TCM symptom score, and serum IL-6, IL-1β, and TNF-α levels decreased in both groups (P P P P P Conclusions: The hot and humid compress of traditional Chinese medicine can effectively relieve pain, restore lumbar function, improve TCM syndromes, reduce the level of inflammatory factors, and have a curative effect in treating LDH.

Optimisation of Thermal Comfort of Building in a Hot and Dry Tropical Climate: A Comparative Approach between Compressed Earth/Concrete Block Envelopes

Compressed earth blocks (CEB) are an alternative to cement blocks in the construction of wall masonry. However, the optimal architectural construction methods for adequate thermal comfort for occupants in hot and arid environments are not mastered. This article evaluates the influence of architectural and constructive modes of buildings made of CEB walls and concrete block walls, to optimize and compare their thermal comfort in the hot and dry tropical climate of Ouagadougou, Burkina Faso. Two identical pilot buildings whose envelopes are made of CEB and concrete blocks were monitored for this study. The thermal models of the pilot buildings were implemented in the SketchUp software using an extension of EnergyPlus. The models were empirically validated after calibration against measured thermal data from the buildings. The models were used to do a parametric analysis for optimization of the thermal performances by simulating plaster coatings on the exterior of walls, airtight openings and natural ventilation depending on external weather conditions. The results show that the CEB building displays 7016 hours of discomfort, equivalent to 80.1% of the time, and the concrete building displays 6948 hours of discomfort, equivalent to 79.3% of the time. The optimization by modifications reduced the discomfort to 2918 and 3125 hours respectively;i.e. equivalent to only 33.3% for the CEB building and 35.7% for the concrete building. More study should evaluate thermal optimizations in buildings in real time of usage such as residential buildings commonly used by the local middle class. The use of CEB as a construction material and passive means of improving thermal comfort is a suitable ecological and economical option to replace cementitious material.

Hot compression behavior and deformation microstructure of Mg-6Zn-1Al-0.3Mn magnesium alloy

The hot compression behavior of a wrought Mg-6Zn-1Al-0.3Mn magnesium alloy was investigated using Gleeble test at 200-400 °C with strain rates ranging from 0.01 to 7 s-1. The true stress-strain curves show that the hot deformation behavior significantly depends on the deformation temperature and strain rate. The calculated hot deformation activation energy Q is 166 kJ/mol with a stress exponent n=5.99, and the constitutive equation is deduced to be ε＆ =3.16×1013[sinh（0.010σ）]5.99exp [-1.66×105/（RT）]· Deformation microstructure shows that the incompletely dynamically recrystallized grains can be found at grain boundaries and twins with the strain rates ranging from 0.01 to 1 s^-1 at 250 °C, and completely dynamic recrystallization occurs when the temperature is 350 °C or above during hot compression, the size of recrystallized grains decreases with the increment of the strain rate at the same temperature. The relatively suitable deformation condition is considered temperature 330-400 °C and strain rate of 0.01-0.03 s-1, and temperature of 350 °C and strain rate of 1 s-1.

High temperature deformation behavior and optimization of hot compression process parameters in TC11 titanium alloy with coarse lamellar original microstructure

The high temperature deformation behaviors of α＋β type titanium alloy TC11 （Ti-6.5Al-3.5Mo-1.5Zr-0.3Si） with coarse lamellar starting microstructure were investigated based on the hot compression tests in the temperature range of 950-1100 ℃ and the strain rate range of 0.001-10 s-1. The processing maps at different strains were then constructed based on the dynamic materials model, and the hot compression process parameters and deformation mechanism were optimized and analyzed, respectively. The results show that the processing maps exhibit two domains with a high efficiency of power dissipation and a flow instability domain with a less efficiency of power dissipation. The types of domains were characterized by convergence and divergence of the efficiency of power dissipation, respectively. The convergent domain in a＋fl phase field is at the temperature of 950-990 ℃ and the strain rate of 0.001-0.01 s^-1, which correspond to a better hot compression process window of α＋β phase field. The peak of efficiency of power dissipation in α＋β phase field is at 950 ℃ and 0.001 s 1, which correspond to the best hot compression process parameters of α＋β phase field. The convergent domain in β phase field is at the temperature of 1020-1080 ℃ and the strain rate of 0.001-0.1 s^-l, which correspond to a better hot compression process window of β phase field. The peak of efficiency of power dissipation in ℃ phase field occurs at 1050 ℃ over the strain rates from 0.001 s^-1 to 0.01 s^-1, which correspond to the best hot compression process parameters of ,8 phase field. The divergence domain occurs at the strain rates above 0.5 s^-1 and in all the tested temperature range, which correspond to flow instability that is manifested as flow localization and indicated by the flow softening phenomenon in stress-- strain curves. The deformation mechanisms of the optimized hot compression process windows in a＋β and β phase fields are identified to be spheroidizing and dynamic recrystallizing controlled by self-diffusion mechanism, respectively. The microstructure observation of the deformed specimens in different domains matches very well with the optimized results.

Dynamic recrystallization mechanisms during hot compression of Mg-Gd-Y-Nd-Zr alloy

Hot compression tests were conducted on a homogenized Mg-7Gd-4Y-1Nd-0.5Zr alloy at 450 ℃ and a strain rate of 2 s-1. Dynamic recrystallization （DRX） mechanisms were investigated by optical microscope （OM）, scanning electron microscope （SEM） and transmission electron microscope （TEM） systematically. The crystallographic orientation information is obtained through electron back-scattering diffraction （EBSD）. The result shows that the flow stress firstly reaches a peak rapidly followed by declining to a valley, and then increases gradually again when the alloy is compressed to a strain of-1.88. DRX related to {10]2} tensile twins is extensively observed at small strains, resulting in an evident grain refinement. DRX grains first nucleate along the edges of twin boundaries with about 30~ （0001） off the twin parents. While at large strains, conventional continuous DRX （CDRX） is frequently identified by the formation of small DRX grains along the original grain boundaries and the continuously increasing misorientation from the centre of large original grains to the grain boundaries. Evidence of particle-stimulated nucleation （PSN） is also observed in the present alloy.

Interaction among deformation, recrystallization and phase transformation of TA2 pure titanium during hot compression

TA2 pure titanium was chosen to research the interaction among deformation, recrystallization and phase transformation during hot compression. The samples were hot compressed by thermal simulation method with different processing parameters. Variant selection induced by stress during cooling after compression was found. The prismatical texture component which featured that the [0001] direction perpendicular to the compressing direction produced preferentially under the compressing stress. As a result, the transformedα phase possesses strong prismatical texture which is different with the basal texture of compressed αphase. The minimum elastic strain energy is demonstrated to be the main reason that causes the variant selection. Dynamic recrystallization behavior and microstructure evolution during hot compression were also studied.

Thermal activation parameters of V-5Cr-5Ti alloy under hot compression

In order to well understand the elementary mechanisms that govern the hot working process of a V？5Cr？5Ti alloy （mass fraction, %）, thermal activation parameters under compression were measured in a temperature range of 1373？1673 K by a Gleeble？3800 system. The results show that the stress exponentn is 4.87 and the activation energyQis 375.89 kJ/mol for the power law equation. The activation energy is determined as 288.34 kJ/mol, which is close to the self-diffusion energy of alloy （270？300 kJ/mol） by introducing a threshold stress（σ0） variable. The typical values of physical activation volume （Vp） and strain rate sensitivity （m） are measured as （120？700）b3 and 0.075？0.122, respectively, by the repeated stress relaxation tests. These activation parameters indicate that the rate controlling mechanism for V？5Cr？5Ti alloy compressed in ranges of 1373？1673 K and 0.001？1.0 s？1 is the dislocation climb by overcoming of forest dislocations.

Effects of hot compression on carbide precipitation behavior of Ni-20Cr-18W-1Mo superalloy

The effect of hot compression on the grain boundary segregation and precipitation behavior of M6C carbide in theNi-20Cr-18W-1Mo superalloy was investigated by thermomechanical simulator, scanning electronic microscope （SEM） and X-raydiffraction （XRD）. Results indicate that the amount of M6C carbides obviously increases in the experimental alloy after hotcompression. Composition analyses reveal that secondary M6C carbides at grain boundaries are highly enriched in tungsten.Meanwhile, the secondary carbide size of compressive samples is 3？5 μm in 10% deformation degree, while the carbide size ofundeformed specimens is less than 1 μm under aging treatment at 900 and 1000 ℃. According to the thermodynamic calculationresults, the Gibbs free energy of γ-matrix and carbides decreases with increase of the compression temperature, and the W-rich M6Ccarbide is more stable than Cr-rich M23C6. Compared with the experimental results, it is found that compressive stress accelerates theW segregation rate in grain boundary region, and further rises the rapid growth of W-rich M6C as compared with the undeformedone.

Flow behavior and microstructure evolution of 6A82 aluminium alloy with high copper content during hot compression deformation at elevated temperatures

The flow behavior and microstructure evolution of 6A82 aluminum alloy (Al?Mg?Si?Cu) with high copper content were studied on a Gleeble?1500 system by isothermal hot compression test in the temperature range from 320 to 530 °C and the strain rate range from 0.001 to 10 s?1. The results reveal that the flow stress of the alloy exhibits a continuous flow softening behavior at low temperatures of 320?390 °C, whereas it reaches steady state at high temperatures (≥460°C), which are influenced greatly by the Zener?Hollomon parameter (Z) in the hyperbolic sine with the hot deformation activation energy of 325.12 kJ/mol. Microstructure characterizations show that prominent dynamic recrystallization and coarsening of dynamic precipitation may be responsible for the continuous flow softening behavior. Due to deformation heating at high strain rates (≥1 s?1), dynamic recrystallization is more prominent in the specimen deformed at 530 °C and 10 s?1 than in the specimen deformed at 460 °C and 0.1 s?1 even though they have very close lnZ values.

Flow stress behavior and processing map of extruded 7075Al/SiC particle reinforced composite prepared by spray deposition during hot compression

Hot compression tests of the extruded 7075Al/15%SiC (volume fraction) particle reinforced composite prepared by spray deposition were performed on Gleeble?1500 system in the temperature range of 300?450 °C and strain rate range of 0.001?1 s?1. The results indicate that the true stress?true strain curve almost exhibits rapid flow softening phenomenon without an obvious work hardening, and the stress decreases with increasing temperature and decreasing strain rate. Moreover, the stress levels are higher at temperature below 400 °C but lower at 450 °C compared with the spray deposited 7075Al alloy. Superplastic deformation characteristics are found at temperature of 450 °C and strain rate range of 0.001?0.1 s?1 with corresponding strain rate sensitivity of 0.72. The optimum parameters of hot working are determined to be temperature of 430?450 °C and strain rate of 0.001?0.05 s?1 based on processing map and optical microstructural observation.

Hot Compression Behavior of As-Cast Precipitation-Hardening Stainless Steel

High temperature deformation characteristics of a semiaustenitic grade of precipitation-hardening stain- less steels were investigated by conducting hot compression tests at temperatures of 900--1 100 ℃ and strain rates of 0. 001--1 s^-1. Flow behavior of this alloy was investigated and it was realized that dynamic recrystallization （DRX） was responsible for flow softening. The correlation between critical strain for initiation of DRX and de- formation parameters including temperature and strain rate, and therefore, Zener-Hollomon parameter （Z） was studied. Metallographic observation was performed to determine the as-deformed microstructure. Microstructural observation shows that recrystallized grain size increases with increasing the temperature and decreasing the strain rate. The activation energy required for DRX of the investigated steel was determined using correlations of flow stress versus temperature and strain rate. The calculated value of activation energy, 460 kJ/mol, is in accordance with other studies on stainless steels. The relationship between peak strain and Z parameter is proposed.

Static softening behaviors of 7055 alloy during the interval time of multi-pass hot compression

Multipass plain strain compression test of 7055 alloy was carried out on Gleeble 1500D thermomechanical simulator to study the effect of interval time on static softening behavior between two passes. Microstructural features of the alloy deformed with delay times varying from 0 to 180 s after achieving a reduction of ,-~52 % in the 13 stages was investigated through TEM and EBSD observations. The 14th pass of peak stresses after different delay times were gained. The peak stress decreases with the interstage delay time increasing, but the decreasing trend is gradually slower. Static recovery, metadynamic recrystallization, and/or static recrystallization can be found in the alloy during two passes. The recovery and recrystallization degree increases with longer interstage delay time. The static recovery is the main softening mechanism. Subgrain coalescence and subgrain growth together with particle-stimulated nucleation are the main nucleation mechanisms for static recrystallization.

Effects of process parameters on the microstructure during the hot compression of a TC6 titanium alloy

The effects of process parameters on the microstructural evolution, includinggrain size and volume traction of the a phase during hot forming of a TC6 alloy were investigatedusing compression tests. Experiments were conducted on the material with (α + β) phases atdeformation temperatures of 800, 860, 920, and 950℃, strain rates of 0.001, 0.01, 1, and 50 s^(-1),and height direction reductions of 30%, 40%, and 50%. After reaching a peak value near 920℃, thegrain size and volume fraction decrease with further increase of deformation temperature. The strainrate affects the morphologies and grain size of α phase of the TC6 titanium alloy. At a lowerstrain rate, the effect of the strain rate on the volume fraction is greater than that at a higherstrain rate under the experimental conditions. The effects of the strain rate on the microstructurealso result from deformation heating. The grain size of the α phase increases with an increase inheight direction reduction after an early drop. The effect of height direction reduction on thevolume fraction is similar to that of the grain size. All of the optical micrographs andquantitative metallography show that deformation process parameters affect the microstructure duringhot forming of the TC6 alloy, and a correlation between the temperature, strain, and strain rateappears to be a significant fuzzy characteristic.

Strain-induced α-to-β phase transformation during hot compression in Ti-5Al-5Mo-5V-1Cr-1Fe alloy

The dynamic phase transformation of Ti-5Al-5Mo-5V-1Cr-1Fe alloy during hot compression below theβtransus temperature was investigated.Strain-inducedα-to-βtransformation is observed in the samples compressed at 0-100 K below theβtransus temperature.The deformation stored energy by compression provides a significant driving force for theα-to-βphase transformation.The re-distribution of the solute elements induced by defects during deformation promotes the occurrence of dynamic transformation.Orientation dependence for theα-to-βphase transformation promotion is observed between{100}-orientated grains and{111}-orientated grains.Incomplete recovery in{111}-orientated grains would create a large amount of diffusion channels,which is in favor of theα-to-βtransformation.The effects of reduction ratio and strain rate on the dynamic phase transformation were also investigated.

Effect of temperature on microstructure and texture evolution of Mg-Zn-Er alloy during hot compression

The microstructure and texture evolutions in Mg-Zn-Er alloy during hot compression were investigated by using opticalmicroscope （OM）, field emission scanning electron microscope （EBSD） and transmission electron microscope （TEM）. The resultsindicate that the temperature plays an important role in dynamic recrystallization （DRX） mechanism. The twin dynamicrecrystallization （TDRX） is induced at a strain of 0.6 because of the activation of non-basal slip （a＋c ） dislocations at 200 ℃.Meanwhile, the continuous DRX （CDRX） occurs at 350℃, which is identified by the typical necklace-like structure around theresidual initial grains. The DRX contributes to the modification of texture significantly. The tension twins are responsible for theweak texture at 200 ℃. Meanwhile, the decrease in the basal texture is ascribed to the DRX sites which transfer from twinboundaries to initial grain boundaries as the temperature is increased from 200 to 350 ℃.

Microstructure and hot compression behavior of twin-roll-casting AZ41M magnesium alloy

The relationship of true stress and true strain of AZ41M magnesium alloy under twin-roll-cast （TRC） and hot compression was analyzed us- ing a Gleeble 1500 machine. Microstructural evolutions of the TRC magnesium alloy under different deformation conditions （strain, sWain rate and deformation temperature） were examined using optical microscopy and discussed. The relationship of true stress and true sWain pre- dicted that lower deformation temperature and higher sWain rate caused sharp strain hardening. Meanwhile, the flow stress curve turned into a steady state at high temperature and lower strain rate. The intermediate temperature and strain rate （623 K and 0.01 s^-1） is appropriate.

Effect of Al_(3)Zr particles on hot-compression behavior and processing map for Al-Cu-Li based alloys at elevated temperatures

The influence of Al3Zr particles on the hot compression behavior and processing map(PM)of Al-Cu-Li based alloys under isothermal plane-strain compression in the temperature range of 400-500℃and at the strain rates of 0.01-10 s^-1 was investigated.The corresponding microstructure was analyzed using optical microscopy(OM),electron back-scattered diffraction(EBSD)and transmission electron microscope(TEM).The results showed that dynamic recovery(DRV)played a greater role than dynamic recrystallization(DRX)in dynamic softening.At low temperatures,the Al3Zr particles were the significant barriers to inhibit DRV and DRX grain growth.When the temperature reached 500℃,the Al3Zr particles readily spread along grain boundaries just like a necklace due to the dissolution of Al3Zr particles and rapid diffusion of Zr through grain boundary,resulting in generating the macroscopic cracks and forming an instability domain at 490-500℃,0.01 s^-1 in the PM.

Research on flow stress of spray formed 70Si30Al alloy under hot compression deformation

The flow stress of spray formed 70Si30Al alloy was studied by hot compression on a Gleeble- 1500 test machine. The experimental results indicated that the flow stress depends on the strain rate and the deformation temperature. The flow stress increases with an increase in strain rate at a given deformation temperature. The flow stress decreases with the deformation temperature increasing at a given strain rate. The relational expression among the flow stress, the swain rate, and the deformation temperature satisfies the Arrhenius equation. The deformation activation energy of 70Si30Al alloy during hot deformation is 866.27 kJ/mol from the Arrhenius equation.

Microstructural evolution,flow stress and constitutive modeling of Al−1.88Mg−0.18Sc−0.084Er alloy during hot compression

To explore the hot compression behavior and microstructural evolution,fine-grained Al−1.88Mg−0.18Sc−0.084Er(wt.%)aluminum alloy wires were fabricated with Castex(continuous casting−extrusion)and ECAP-Conform,and their hot compression behavior was investigated at temperatures of 673−793 K and strain rates of 0.001−10 s−1;the microstructures were characterized by optical microscope,X-ray diffractometer,transmission electron microscope,and electron backscattered diffractometer,and the flow stresses were obtained by thermal compression simulator.Microstructural evolution and flow curves reveal that dynamic recovery is the dominant softening mechanism.Continuous dynamic recrystallization followed by dynamic grain growth takes place at a temperature of 773 K and a strain rate of 0.001 s−1;the yielding drop phenomenon was discovered.Hyperbolic sine constitutive equation incorporating dislocation variables was presented,and a power law constitutive equation was established.The stress exponent is 3.262,and the activation energy for deformation is 154.465 kJ/mol,indicating that dislocation viscous glide is the dominant deformation mechanism.

Hot workability of cast and wrought Ni-42Cu alloy through hot tensile and compression tests

In order to analyze the flow behavior and workability of Ni-42Cu in cast and wrought conditions, hot deformation tests were performed at temperatures and strain rates within the ranges of 900-1150 ℃ and 0.001-1 s^-1, respectively. Tensile tests showed a “hot ductility trough” at 950 ℃ for both alloys. The drop in hot ductility was more considerable in the cast alloy because of the sluggish dynamic recrystallization. The hot ductility drop and grain boundary cracking, particularly in the cast alloy, were attributed to the segregation of detrimental atoms to the boundaries. It was shown that the hot ductility of the wrought alloy could be improved with increasing strain rate. It was associated with increasing the fraction of dynamic recrystallization at higher strain rates. This finding corroborated the change in the mechanism of dynamic recrystallization with strain rate. The strain rate sensitivity and instability parameters calculated for the wrought alloy showed that the material is prone to strain localization at low temperatures, i.e., 950-1050 ℃, and high strain rates of 0.1 and 1 s-1. Based on the tensile and compression tests, the best temperature range for a desirable hot workability was introduced as 1050-1150 ℃.