Oxidative stress disturbs the balance between the production of reactive oxygen species(ROS)and the detoxification biological process.It plays an important role in the development and progression of many chronic disea...Oxidative stress disturbs the balance between the production of reactive oxygen species(ROS)and the detoxification biological process.It plays an important role in the development and progression of many chronic diseases.Upon exposure to oxidative stress or the inducers of ROS,the cellular nucleus undergoes some biological processes via different signaling pathways,such as stress adaption through the forkhead box O signaling pathway,inflammatory response through the IκB kinase/nuclear factor-κB signaling pathway,hypoxic response via the hypoxia-inducible factor/prolyl hydroxylase domain proteins pathway,DNA repair or apoptosis through the p53 signaling pathway,and antioxidant response through the Kelch-like ECH-associated protein 1/nuclear factor E2-related factor 2 signaling pathway.These processes are involved in many diseases.Therefore,oxidative stress has gained more attraction as a targeting process for disease treatment.Meanwhile,anti-oxidative stress agents have been widely explored in pre-clinical trials.However,only limited clinical trials are performed to evaluate the efficacy of anti-oxidative stress agents or antioxidants in diseases.In this letter,we further discuss the current clinical trials related to anti-oxidative stress treatment in different diseases.More pre-clinical studies and clinical trials are expected to use anti-oxidative stress strategies as disease treatment or dietary supplementation to improve disease treatment outcomes.展开更多
Brain ischemic stroke is the leading cause of long-lasting injury,disability,and death in adults.Although the brain represents only about 2%of the total body mass,it consumes almost 20%of the body＇s oxygen.As a resul...Brain ischemic stroke is the leading cause of long-lasting injury,disability,and death in adults.Although the brain represents only about 2%of the total body mass,it consumes almost 20%of the body＇s oxygen.As a result,brain cells are extremely sensitive to hypoxia.Once cerebral ischemia occurs.展开更多
Zonal heat treatment(ZHT) was conducted in situ to 14.5 mm-thick TC4 alloy plates by means of defocused electron beam after welding. The effects of ZHT on residual stresses,microstructures and mechanical properties of...Zonal heat treatment(ZHT) was conducted in situ to 14.5 mm-thick TC4 alloy plates by means of defocused electron beam after welding. The effects of ZHT on residual stresses,microstructures and mechanical properties of electron beam welded joints were investigated. Experimental results show residual stresses after welding are mostly relieved through ZHT,and the maximum values of longitudinal tensile stress and transverse compressive stress reduce by 76% and 65%,respectively. The tensile strength and ductility of welded joint after ZHT at slow scanning velocity are improved because of the reduction of residual stress and the microstructural changes of the base and weld metal. ZHT at fast scanning velocity is detrimental to the ductility of welded joint,which is resulted from insufficiently coarsened alpha phase in the fusion zone and the appearance of martensite in the base metal.展开更多
hi this paper, the non-linear finite element method had been applied to calculate the thermal stress evolving process of the large-scale bearing roller during heating process of final heat treatment. It was found that...hi this paper, the non-linear finite element method had been applied to calculate the thermal stress evolving process of the large-scale bearing roller during heating process of final heat treatment. It was found that two stress peaks appeared during heating process and the second stress peak was higher than the first. If the preheating time was elongated, the second stress peak was reduced distinctly. Therefore, the pre-heating time should be elongated suitably to ensure safety in the practical manufacture process.展开更多
Alcohol use disorder （AUD）, mild traumatic brain injury （mTBI）, and posttraumatic stress disorder （PTSD） commonly co-occur （AUD ＋ mTBI ＋ PTSD）. These conditions have overlapping symptoms which are, in part, ...Alcohol use disorder （AUD）, mild traumatic brain injury （mTBI）, and posttraumatic stress disorder （PTSD） commonly co-occur （AUD ＋ mTBI ＋ PTSD）. These conditions have overlapping symptoms which are, in part, reflective of overlapping neuropathology. These conditions become problematic because their co-occurrence can exacerbate symptoms. Therefore, treatments must be developed that are inclusive to all three conditions. Repetitive transcranial magnetic stimulation （rTMS） is non-invasive and may be an ideal treatment for co-occurring AUD ＋ mTBI ＋ PTSD. There is accumulating evidence on rTMS as a treatment for people with AUD, mTBI, and PTSD each alone. However, there are no published studies to date on rTMS as a treatment for co-occurring AUD ＋ mTBI ＋ PTSD. This review article advances the knowledge base for rTMS as a treatment for AUD ＋ mTBI ＋ PTSD. This review provides background information about these co-occurring conditions as well as rTMS. The existing literature on rTMS as a treatment for people with AUD, TBI, and PTSD each alone is reviewed. Finally, neurobiological findings in support of a theoretical model are discussed to inform TMS as a treatment for co-occurring AUD ＋ mTBI ＋ PTSD. The peer-reviewed literature was identified by targeted literature searches using PubMed and supplemented by cross-referencing the bibliographies of relevant review articles. The existing evidence on rTMS as a treatment for these conditions in isolation, coupled with the overlapping neuropathology and symptomology of these conditions, suggests that rTMS may be well suited for the treatment of these conditions together.展开更多
In order to study the effects of aging treatment on the intergranular corrosion（IGC） and stress corrosion cracking（SCC） of 7003 aluminum alloy（AA7003）, the intergranular corrosion test, electrochemical test and ...In order to study the effects of aging treatment on the intergranular corrosion（IGC） and stress corrosion cracking（SCC） of 7003 aluminum alloy（AA7003）, the intergranular corrosion test, electrochemical test and slow strain rate test（SSRT）, combined with optical microscopy（OM） and scanning electron microscopy（SEM） as well as transmission electron microscopy（TEM） observations have been carried out. The IGC and electrochemical test results showed that the IGC resistance of AA7003 for peak aged（PA） temper is the lowest, with double peak aged（DPA） the moderate, and retrogression and re-aging（RRA） the highest among three tempers, which is attributed to the continuous feature of precipitation on grain boundary of PA temper and the interrupted feature of precipitation on grain boundary of DPA and RRA tempers, as well as the wide precipitation free zones（PFZ） of RRA temper. In addition, the SSRT results indicated that all three tempers AA7003 are susceptible to SCC in IGC solution, and the change tendency of SCC susceptibility（ISCC） of AA7003 for three tempers follows the order： ISCC（RRA）展开更多
The explosion treatment technique has been used in the relief of residual stresses in 800 MPa grade high strength steel manual welded joints. The residual stresses on surface and through thickness of the weldment were...The explosion treatment technique has been used in the relief of residual stresses in 800 MPa grade high strength steel manual welded joints. The residual stresses on surface and through thickness of the weldment were measured for both as-welded and explosion-treated sample, the mechanical properties of welded joints under different conditions were also tested. The effect of explosion treatment on the fracture toughness of materials with a residual defect was investigated by crack opening displacement （COD） test. The results show that explosion treatment can reduce not only the surface residual stress but also the residual stress through thickness in the welded joints. The effect of explosion treatment on the mechanical properties and a residual defect in welded joint were inconspicuous.展开更多
The Complementary and Alternative Medicine Education (EDUCAM) School of Osteopathy, following the earthquake that occurred in Amatrice-Italy on August 24th 2016, promoted the project “Una mano per la salute” [One ha...The Complementary and Alternative Medicine Education (EDUCAM) School of Osteopathy, following the earthquake that occurred in Amatrice-Italy on August 24th 2016, promoted the project “Una mano per la salute” [One hand for health], aimed at giving therapeutic support to the population affected by this cataclysm. A review of the literature in the osteopathic field has been performed to identify a more functional approach to quickly relieve the inhabitants from the shock they suffered, and to identify the techniques with greater effectiveness on the stress axis. The protocol of ten chosen techniques will then be verified later in a pilot study, to check whether and how a protocol of osteopathic manipulative treatment (OMT) might play a clinically relevant role in the management of subjects exposed to extraordinary exogenous stress and post-traumatic stress disorder (PTSD) prevention, in addition to the psychological therapy treatments in use today.展开更多
In order to improve the stress corrosion cracking(SCC) resistance of 7A05Al alloy, four different heat treatment processes were performed. After the heat treatments, the stress corrosion cracking resistance, mechanica...In order to improve the stress corrosion cracking(SCC) resistance of 7A05Al alloy, four different heat treatment processes were performed. After the heat treatments, the stress corrosion cracking resistance, mechanical properties and microstructures of 7A05A1 alloys were studied. The results show that the retrogression and reaging(RRA) treated specimens possess the highest SCC resistance with slightly reduced strength compared with the other specimens. Thus RRA is the best process in terms of the optimal combination of SCC resistance and strength. Further TEM observation reveals that the RRA treated specimens are characterized by the fine equiaxed grains, dispersed second phase and wide PFZ. The pre-aging treated specimens show lower SCC resistance but higher strength as compared with the RRA treated ones. Equiaxed grains are also observed in the pre-aging treated samples by TEM, indicating that the anisotropy is eliminated. However, the dual aging and deformation plus aging treated specimens are demonstrated by large anisotropy.展开更多
The behavior that different magnetic treatment directions induce various amounts of welding residual stress reductions in low alloy steel was studied. Reductions of 26%-28% in the longitudinal stress σ x were obtaine...The behavior that different magnetic treatment directions induce various amounts of welding residual stress reductions in low alloy steel was studied. Reductions of 26%-28% in the longitudinal stress σ x were obtained when low frequency alternating magnetic treatment was applied perpendicularly to the welding bead, whereas reductions of 20%-21% in σ x were measured by using the same treatment parameters except that the field direction was applied parallel to the bead. It is proposed that different extent of stress reductions caused by the above two treatment directions is attributed primarily to the alteration of the energy absorbed by domains from the external magnetic field, which part of energy can arouse plastic deformation in microstructures by the motion of domain walls.展开更多
The distributions of temperature and residual stresses in thin plates of BT20titanium alloy are numerically analyzed by three-dimensional finite element software duringelectron beam welding and electron beam local pos...The distributions of temperature and residual stresses in thin plates of BT20titanium alloy are numerically analyzed by three-dimensional finite element software duringelectron beam welding and electron beam local post-weld heat treatment (EBLPWHT). Combined withnumerical calculating results, the effects of different EBLPWHT mode and parameters, including heattreating position, heating width and heating time, on the distribution of welding residual stressesare analyzed. The results show that, the residual tensile stresses in weld center can be largelydecreased when the weld is heat treated at back preface of the plate. The numerical results alsoindicated that the magnitude of the residual longitudinal stresses of the weld and the zone vicinityof the weld is decreased, and the range of the residual longitudinal stresses is increased alongwith the increase of heating width and heating time.展开更多
Comparative investigations were carried out of the effect of heat treatment regimes Jor steel GC-4(40CrMnSiMoVA)on its crack propagating rates,from corrosion fatigue, (da/dN)_(CF),or stress corrosion cracking,(da/dt)_...Comparative investigations were carried out of the effect of heat treatment regimes Jor steel GC-4(40CrMnSiMoVA)on its crack propagating rates,from corrosion fatigue, (da/dN)_(CF),or stress corrosion cracking,(da/dt)_(SCC),in media with various constituents and pH values.Both(da/dN)_(CF) and(da/dt)_(SCC) accelerate with the increase of yield stress of the steel,yet the former is far less than the later.In comparison with media,the (da/dt)_(SCC) in distilled water is slightly greater than that in 3.5% NaCl solution,and the (da/dN)_(CF) in distilled water is far less than that in 3.5% NaCl solution.With the pH value increasing in 3.5% NaCl solution,the(da/dN)_(CF) lowers down and the(da/dt)_(SCC) speeds up.An explanation was also proposed with concept of the cyclic hardening and softening at crack tip,as well as the crack closure and occluded cell effect.展开更多
From comparing the test of local explosion treatment(LET)with the locaf heat treatment (LHT)in welded plates and welded steel pipes in field,LET has excellent effect of stress relief and high efficiency. Whereas the e...From comparing the test of local explosion treatment(LET)with the locaf heat treatment (LHT)in welded plates and welded steel pipes in field,LET has excellent effect of stress relief and high efficiency. Whereas the effect of stress relief for LHT with 575℃×1.5hr is poor.The mechanical properties of welded joints after LET are basically the same as those of as-welded joints.The practically measuring results on 4 large steel-pipe surfaces indicate that the welding residual tensile stresses in welds,which mostly is compression residual stress,are basically relieved.展开更多
The standard heat treatment of cast nickel base superalloy K403 is the solid solution treatment of 1210℃/4h, air cooling. It is very difficult to meet the requirements of Aviation Standard HB5155, in which the stre...The standard heat treatment of cast nickel base superalloy K403 is the solid solution treatment of 1210℃/4h, air cooling. It is very difficult to meet the requirements of Aviation Standard HB5155, in which the stress rupture life at 750℃ and 645MPa is longer than 50h. The results showed that the intermediate temperature stress rupture properties impaired by treatment of 1210℃/4h were due to precipitation of too small γ′ phase(<0.2μm) in grains and absence of the secondary carbides at grain boundaries. Microstructure containing the intergranular M6C carbides with envelope of γ′ and the residual coarse γ′ was obtained by means of 1180℃/4h treatment, therefore the stress rupture life was obviously increased to meet the demand of HB5155. The effect of γ′ size was also discussed from the view point of deformation mechanism in this paper.展开更多
The use of injectable agents for the treatment of stress urinary incontinence(SUI)is an option for female patients who are unwilling to undergo surgery,or have concurrent conditions or diseases that render surgical tr...The use of injectable agents for the treatment of stress urinary incontinence(SUI)is an option for female patients who are unwilling to undergo surgery,or have concurrent conditions or diseases that render surgical treatment unsuitable.To be effective for SUI,an injectable agent must be nonimmunogenic,hypoallergenic,biocompatible,permanent,nonerosive,nonmigratory and painless.It must also heal with minimal fibrosis,possess a long-term bulking effect,and be easily stored and handled.Glutaraldehyde cross-linked bovine collagen(Contigen),silicone polymers(Macroplastique),Durasphere,calcium hydroxyapatite(Coaptite),polyacrylamide hydrogel(Aquamid,Bulkamid),Permacol,and stem cell therapy have been used as injectable agents.Patients must be informed that treatment with injectable agents is not as effective as surgical treatment,and that such agents might necessitate additional and repeated administrations in order to achieve the desired therapeutic effect.展开更多
The hardness and residual stress in the forging for cold roller during low temperature tempering,and the relationship of residual stress and cooling temperature of high temperature tempering for heavy forgings were st...The hardness and residual stress in the forging for cold roller during low temperature tempering,and the relationship of residual stress and cooling temperature of high temperature tempering for heavy forgings were studied.The stress relaxation constant at low temperature tempering and the elasto-plastisity inversion temperature at high temperature tempering were found.The results are of great importance to determine rational tempering cooling process of heavy forgings.展开更多
This work aims to describe a well standardized therapeutic path in reference to the article “Osteopathy and Emergency: A Model of Osteopathic Treatment Aimed at Managing the Post-Traumatic Stress—Part 1 in the form ...This work aims to describe a well standardized therapeutic path in reference to the article “Osteopathy and Emergency: A Model of Osteopathic Treatment Aimed at Managing the Post-Traumatic Stress—Part 1 in the form of a practical guide for manual therapist, Open Journal of Therapy and Rehabilitation, Vol. 10, No. 7, July 2018, https://doi.org/10.4236/health.2018.107074”. The osteopathic manipulative treatment (OMT) approach we propose can be complementary to the psychological therapy in use today, and consists of ten standardized techniques directed to the anatomical structures more involved in the stress answer. This protocol was designed to improve and sustain the management of subjects exposed to extraordinary exogenous stress or post-traumatic stress disorder patients (PTSD).展开更多
文摘Oxidative stress disturbs the balance between the production of reactive oxygen species(ROS)and the detoxification biological process.It plays an important role in the development and progression of many chronic diseases.Upon exposure to oxidative stress or the inducers of ROS,the cellular nucleus undergoes some biological processes via different signaling pathways,such as stress adaption through the forkhead box O signaling pathway,inflammatory response through the IκB kinase/nuclear factor-κB signaling pathway,hypoxic response via the hypoxia-inducible factor/prolyl hydroxylase domain proteins pathway,DNA repair or apoptosis through the p53 signaling pathway,and antioxidant response through the Kelch-like ECH-associated protein 1/nuclear factor E2-related factor 2 signaling pathway.These processes are involved in many diseases.Therefore,oxidative stress has gained more attraction as a targeting process for disease treatment.Meanwhile,anti-oxidative stress agents have been widely explored in pre-clinical trials.However,only limited clinical trials are performed to evaluate the efficacy of anti-oxidative stress agents or antioxidants in diseases.In this letter,we further discuss the current clinical trials related to anti-oxidative stress treatment in different diseases.More pre-clinical studies and clinical trials are expected to use anti-oxidative stress strategies as disease treatment or dietary supplementation to improve disease treatment outcomes.
文摘Brain ischemic stroke is the leading cause of long-lasting injury,disability,and death in adults.Although the brain represents only about 2%of the total body mass,it consumes almost 20%of the body＇s oxygen.As a result,brain cells are extremely sensitive to hypoxia.Once cerebral ischemia occurs.
文摘Zonal heat treatment(ZHT) was conducted in situ to 14.5 mm-thick TC4 alloy plates by means of defocused electron beam after welding. The effects of ZHT on residual stresses,microstructures and mechanical properties of electron beam welded joints were investigated. Experimental results show residual stresses after welding are mostly relieved through ZHT,and the maximum values of longitudinal tensile stress and transverse compressive stress reduce by 76% and 65%,respectively. The tensile strength and ductility of welded joint after ZHT at slow scanning velocity are improved because of the reduction of residual stress and the microstructural changes of the base and weld metal. ZHT at fast scanning velocity is detrimental to the ductility of welded joint,which is resulted from insufficiently coarsened alpha phase in the fusion zone and the appearance of martensite in the base metal.
文摘hi this paper, the non-linear finite element method had been applied to calculate the thermal stress evolving process of the large-scale bearing roller during heating process of final heat treatment. It was found that two stress peaks appeared during heating process and the second stress peak was higher than the first. If the preheating time was elongated, the second stress peak was reduced distinctly. Therefore, the pre-heating time should be elongated suitably to ensure safety in the practical manufacture process.
基金supported with resources by Department of Veterans Affairs(VA),Health Services Research and Development Service and the Office of Academic Affiliations(TPP 42-013)at Edward Hines VA Hospitalsupported by the following:VA OAA Polytrauma Fellowship to AAH,NIDRR Merit Switzer Research Fellowship Award H133F130011to AAH and the VA RR&D CDA-II RX000949-01A2 to AAH
文摘Alcohol use disorder （AUD）, mild traumatic brain injury （mTBI）, and posttraumatic stress disorder （PTSD） commonly co-occur （AUD ＋ mTBI ＋ PTSD）. These conditions have overlapping symptoms which are, in part, reflective of overlapping neuropathology. These conditions become problematic because their co-occurrence can exacerbate symptoms. Therefore, treatments must be developed that are inclusive to all three conditions. Repetitive transcranial magnetic stimulation （rTMS） is non-invasive and may be an ideal treatment for co-occurring AUD ＋ mTBI ＋ PTSD. There is accumulating evidence on rTMS as a treatment for people with AUD, mTBI, and PTSD each alone. However, there are no published studies to date on rTMS as a treatment for co-occurring AUD ＋ mTBI ＋ PTSD. This review article advances the knowledge base for rTMS as a treatment for AUD ＋ mTBI ＋ PTSD. This review provides background information about these co-occurring conditions as well as rTMS. The existing literature on rTMS as a treatment for people with AUD, TBI, and PTSD each alone is reviewed. Finally, neurobiological findings in support of a theoretical model are discussed to inform TMS as a treatment for co-occurring AUD ＋ mTBI ＋ PTSD. The peer-reviewed literature was identified by targeted literature searches using PubMed and supplemented by cross-referencing the bibliographies of relevant review articles. The existing evidence on rTMS as a treatment for these conditions in isolation, coupled with the overlapping neuropathology and symptomology of these conditions, suggests that rTMS may be well suited for the treatment of these conditions together.
基金Funded by the National Natural Science Foundation of China(No.51371039)
文摘In order to study the effects of aging treatment on the intergranular corrosion（IGC） and stress corrosion cracking（SCC） of 7003 aluminum alloy（AA7003）, the intergranular corrosion test, electrochemical test and slow strain rate test（SSRT）, combined with optical microscopy（OM） and scanning electron microscopy（SEM） as well as transmission electron microscopy（TEM） observations have been carried out. The IGC and electrochemical test results showed that the IGC resistance of AA7003 for peak aged（PA） temper is the lowest, with double peak aged（DPA） the moderate, and retrogression and re-aging（RRA） the highest among three tempers, which is attributed to the continuous feature of precipitation on grain boundary of PA temper and the interrupted feature of precipitation on grain boundary of DPA and RRA tempers, as well as the wide precipitation free zones（PFZ） of RRA temper. In addition, the SSRT results indicated that all three tempers AA7003 are susceptible to SCC in IGC solution, and the change tendency of SCC susceptibility（ISCC） of AA7003 for three tempers follows the order： ISCC（RRA）
文摘The explosion treatment technique has been used in the relief of residual stresses in 800 MPa grade high strength steel manual welded joints. The residual stresses on surface and through thickness of the weldment were measured for both as-welded and explosion-treated sample, the mechanical properties of welded joints under different conditions were also tested. The effect of explosion treatment on the fracture toughness of materials with a residual defect was investigated by crack opening displacement （COD） test. The results show that explosion treatment can reduce not only the surface residual stress but also the residual stress through thickness in the welded joints. The effect of explosion treatment on the mechanical properties and a residual defect in welded joint were inconspicuous.
文摘The Complementary and Alternative Medicine Education (EDUCAM) School of Osteopathy, following the earthquake that occurred in Amatrice-Italy on August 24th 2016, promoted the project “Una mano per la salute” [One hand for health], aimed at giving therapeutic support to the population affected by this cataclysm. A review of the literature in the osteopathic field has been performed to identify a more functional approach to quickly relieve the inhabitants from the shock they suffered, and to identify the techniques with greater effectiveness on the stress axis. The protocol of ten chosen techniques will then be verified later in a pilot study, to check whether and how a protocol of osteopathic manipulative treatment (OMT) might play a clinically relevant role in the management of subjects exposed to extraordinary exogenous stress and post-traumatic stress disorder (PTSD) prevention, in addition to the psychological therapy treatments in use today.
基金Project(Z172003A001) supported by the Ministerial Level Research Foundation
文摘In order to improve the stress corrosion cracking(SCC) resistance of 7A05Al alloy, four different heat treatment processes were performed. After the heat treatments, the stress corrosion cracking resistance, mechanical properties and microstructures of 7A05A1 alloys were studied. The results show that the retrogression and reaging(RRA) treated specimens possess the highest SCC resistance with slightly reduced strength compared with the other specimens. Thus RRA is the best process in terms of the optimal combination of SCC resistance and strength. Further TEM observation reveals that the RRA treated specimens are characterized by the fine equiaxed grains, dispersed second phase and wide PFZ. The pre-aging treated specimens show lower SCC resistance but higher strength as compared with the RRA treated ones. Equiaxed grains are also observed in the pre-aging treated samples by TEM, indicating that the anisotropy is eliminated. However, the dual aging and deformation plus aging treated specimens are demonstrated by large anisotropy.
基金Funded by the Teaching and Research Award Program for Outstanding Young Teachers in Higher Education Institutions of Ministry of Education, China (No. [2002] 383)Science and Technology Planning Project of Wuhan City, China (No. 20067003111-05)
文摘The behavior that different magnetic treatment directions induce various amounts of welding residual stress reductions in low alloy steel was studied. Reductions of 26%-28% in the longitudinal stress σ x were obtained when low frequency alternating magnetic treatment was applied perpendicularly to the welding bead, whereas reductions of 20%-21% in σ x were measured by using the same treatment parameters except that the field direction was applied parallel to the bead. It is proposed that different extent of stress reductions caused by the above two treatment directions is attributed primarily to the alteration of the energy absorbed by domains from the external magnetic field, which part of energy can arouse plastic deformation in microstructures by the motion of domain walls.
基金This project is supported by Foundation of National Defense Technology Key Laboratory, China (No.99JS50.3.2JW1402).
文摘The distributions of temperature and residual stresses in thin plates of BT20titanium alloy are numerically analyzed by three-dimensional finite element software duringelectron beam welding and electron beam local post-weld heat treatment (EBLPWHT). Combined withnumerical calculating results, the effects of different EBLPWHT mode and parameters, including heattreating position, heating width and heating time, on the distribution of welding residual stressesare analyzed. The results show that, the residual tensile stresses in weld center can be largelydecreased when the weld is heat treated at back preface of the plate. The numerical results alsoindicated that the magnitude of the residual longitudinal stresses of the weld and the zone vicinityof the weld is decreased, and the range of the residual longitudinal stresses is increased alongwith the increase of heating width and heating time.
文摘Comparative investigations were carried out of the effect of heat treatment regimes Jor steel GC-4(40CrMnSiMoVA)on its crack propagating rates,from corrosion fatigue, (da/dN)_(CF),or stress corrosion cracking,(da/dt)_(SCC),in media with various constituents and pH values.Both(da/dN)_(CF) and(da/dt)_(SCC) accelerate with the increase of yield stress of the steel,yet the former is far less than the later.In comparison with media,the (da/dt)_(SCC) in distilled water is slightly greater than that in 3.5% NaCl solution,and the (da/dN)_(CF) in distilled water is far less than that in 3.5% NaCl solution.With the pH value increasing in 3.5% NaCl solution,the(da/dN)_(CF) lowers down and the(da/dt)_(SCC) speeds up.An explanation was also proposed with concept of the cyclic hardening and softening at crack tip,as well as the crack closure and occluded cell effect.
文摘From comparing the test of local explosion treatment(LET)with the locaf heat treatment (LHT)in welded plates and welded steel pipes in field,LET has excellent effect of stress relief and high efficiency. Whereas the effect of stress relief for LHT with 575℃×1.5hr is poor.The mechanical properties of welded joints after LET are basically the same as those of as-welded joints.The practically measuring results on 4 large steel-pipe surfaces indicate that the welding residual tensile stresses in welds,which mostly is compression residual stress,are basically relieved.
文摘The standard heat treatment of cast nickel base superalloy K403 is the solid solution treatment of 1210℃/4h, air cooling. It is very difficult to meet the requirements of Aviation Standard HB5155, in which the stress rupture life at 750℃ and 645MPa is longer than 50h. The results showed that the intermediate temperature stress rupture properties impaired by treatment of 1210℃/4h were due to precipitation of too small γ′ phase(<0.2μm) in grains and absence of the secondary carbides at grain boundaries. Microstructure containing the intergranular M6C carbides with envelope of γ′ and the residual coarse γ′ was obtained by means of 1180℃/4h treatment, therefore the stress rupture life was obviously increased to meet the demand of HB5155. The effect of γ′ size was also discussed from the view point of deformation mechanism in this paper.
文摘The use of injectable agents for the treatment of stress urinary incontinence(SUI)is an option for female patients who are unwilling to undergo surgery,or have concurrent conditions or diseases that render surgical treatment unsuitable.To be effective for SUI,an injectable agent must be nonimmunogenic,hypoallergenic,biocompatible,permanent,nonerosive,nonmigratory and painless.It must also heal with minimal fibrosis,possess a long-term bulking effect,and be easily stored and handled.Glutaraldehyde cross-linked bovine collagen(Contigen),silicone polymers(Macroplastique),Durasphere,calcium hydroxyapatite(Coaptite),polyacrylamide hydrogel(Aquamid,Bulkamid),Permacol,and stem cell therapy have been used as injectable agents.Patients must be informed that treatment with injectable agents is not as effective as surgical treatment,and that such agents might necessitate additional and repeated administrations in order to achieve the desired therapeutic effect.
文摘The hardness and residual stress in the forging for cold roller during low temperature tempering,and the relationship of residual stress and cooling temperature of high temperature tempering for heavy forgings were studied.The stress relaxation constant at low temperature tempering and the elasto-plastisity inversion temperature at high temperature tempering were found.The results are of great importance to determine rational tempering cooling process of heavy forgings.
文摘This work aims to describe a well standardized therapeutic path in reference to the article “Osteopathy and Emergency: A Model of Osteopathic Treatment Aimed at Managing the Post-Traumatic Stress—Part 1 in the form of a practical guide for manual therapist, Open Journal of Therapy and Rehabilitation, Vol. 10, No. 7, July 2018, https://doi.org/10.4236/health.2018.107074”. The osteopathic manipulative treatment (OMT) approach we propose can be complementary to the psychological therapy in use today, and consists of ten standardized techniques directed to the anatomical structures more involved in the stress answer. This protocol was designed to improve and sustain the management of subjects exposed to extraordinary exogenous stress or post-traumatic stress disorder patients (PTSD).
