Photonic-engineered passive radiative cooling built into decorative climate-controlled enclosures reduces the active power consumption of the existing enclosure without sacrificing its aesthetics.
The histogensis of extramammary Paget's disease has not been solved and remained controversial. Eight cases of extramammary Paget's disease of geni-tocrural region were investigated by alcian blue and PAS stai...The histogensis of extramammary Paget's disease has not been solved and remained controversial. Eight cases of extramammary Paget's disease of geni-tocrural region were investigated by alcian blue and PAS stain and immunoreaction of anti-CEA and anti-keratin. It was found that the pattern and intensity of alcian blue, PAS staining were identical for Paget cells and secretory cells of apocrine sweat gland; and CEA immunoreactivity was uniformly observed in both Paget cells and eccrine sweat gland. The keratin immunoreaction was positive in keratinocytes, apocrine and eccrine sweat gland, whereas Paget cells were negative. These results suggested that Paget cells of extramammary Paget's disease could be derived from multipotential epidermal germ cells.展开更多
To formulate the optimal strategy of combatting bacterial biofilms,in this review we update current knowledge on the growing problem of biofilm formation and its resistance to antibiotics which has spurred the search ...To formulate the optimal strategy of combatting bacterial biofilms,in this review we update current knowledge on the growing problem of biofilm formation and its resistance to antibiotics which has spurred the search for new strategies to deal with this complication.Based on recent findings,the role of bacteriophages in the prevention and elimination of biofilm-related infections has been emphasized.In vitro,ex vivo and in vivo biofilm treatment models with single bacteriophages or phage cocktails have been compared.A combined use of bacteriophages with antibiotics in vitro or in vivo confirms earlier reports of the synergistic effect of these agents in improving biofilm removal.Furthermore,studies on the application of phage-derived lysins in vitro,ex vivo or in vivo against biofilm-related infections are encouraging.The strategy of combined use of phage and antibiotics seems to be different from using lysins and antibiotics.These findings suggest that phages and lysins alone or in combination with antibiotics may be an efficient weapon against biofilm formation in vivo and ex vivo,which could be useful in formulating novel strategies to combat bacterial infections.Those findings proved to be relevant in the prevention and destruction of biofilms occurring during urinary tract infections,orthopedic implant-related infections,periodontal and peri-implant infections.In conclusion,it appears that most efficient strategy of eliminating biofilms involves phages or lysins in combination with antibiotics,but the optimal scheme of their administration requires further studies.展开更多
The utilization of pure hydrogen as an energy source in fuel cells gave rise to renewed interest in developing active and stable water-gas shift catalysts. Gold catalysts have proven to be very efficient for water-gas...The utilization of pure hydrogen as an energy source in fuel cells gave rise to renewed interest in developing active and stable water-gas shift catalysts. Gold catalysts have proven to be very efficient for water-gas shift reaction at low temperature. The aim of the present study was to investigate the effect of:(i) different preparation methods(impregnation and coprecipitation) to obtain a modified ceria support,and(ii) the amount of Y_2 O_3(1.0 wt%, 2.5 wt%, 5.0 wt% and 7.5 wt%) as dopant on the water-gas shift activity of Au/CeO_2 catalysts. An extended characterization by means of S_(BET), XRD, HRTEM/HAADF, FTIR,H_2-TPR and CO-TPR measurements in combination with careful evaluation of the catalyst behavior allowed to shed light on the parameters governing the water-gas shift activity. The catalysts show very high activity(>90% CO conversion) in the temperature range 180-220 ℃,with a slightly better performance of the gold catalysts on supports prepared by impregnation. The decreased activity with increasing Y_2 O_3 concentration is related to the hindering of oxygen mobility due to ordering of surface oxygen vacancies in vicinity of segregated Y^(3+). The effect of catalyst pre-treatments and the stability of the best performing samples were examined as well.展开更多
Deformation behavior as well as microstructural evolutions of a rolled AZ31 magnesium alloy with and without pre-existing extension twins were studied using compression tests which performed along different orientatio...Deformation behavior as well as microstructural evolutions of a rolled AZ31 magnesium alloy with and without pre-existing extension twins were studied using compression tests which performed along different orientations at a temperature range of 25–350 ℃. The results implied that the initial texture not only influence the evolution of flow stress, but also change the size and fraction of recrystallized grains.In contrast to samples parallel to rolling and transverse directions, compression along normal direction resulted in a respectful softening at 150 ℃. The largest size and fraction of new grains at 250 ℃ were recorded after deformation along rolling direction, while the maximum flow softening was observed during deformation along normal direction. The anisotropy in microstructural evolutions was still retained at 350 ℃. Pre-existing twins could reduce the anisotropy of material in respect of flow stress as well as DRX progression, where TD sample showed the lowest DRX fraction at 250 ℃. Quaternion misorientation data obtained from EBSD analysis of pretwinned material implied that initial texture could not significantly influence final texture. A different misorientation distribution was realized after deformation of pretwinned material along ND and RD directions.展开更多
In this article,varied praseodymium polyphosphate hosts:MI(Li,Na K)Pr(PO3)4 microcrystals and LiLa1-xPrx(PO3)4(x = 0.01 ^-1)nanocrystals were successfully synthesized by the flux method and the coprecipitation techniq...In this article,varied praseodymium polyphosphate hosts:MI(Li,Na K)Pr(PO3)4 microcrystals and LiLa1-xPrx(PO3)4(x = 0.01 ^-1)nanocrystals were successfully synthesized by the flux method and the coprecipitation technique,respectively.The size of stoichiometric nanocrystals of LiPr(PO3)4 was tuned by the te mpe rature of thermal treatment in range of 35-145 nm.In order to dete rmine the most suitable material for the non-contact optical thermometric applications,the temperature sensing measurements were carried out by using luminescence intensity ratio(LIR)of emission bands corresponding to the ^3 P1→ ^3H5 and ^3P0→ ^3 H5 electronic transitions of Pr3+ ions into the 123-423 K temperature range.The influence of the host material composition of MⅠ(Li,Na,K)Pr(PO3)4 microcrystals on the sensitivity of luminescent thermometers was studied.It is found that the sensitivity of lithium praseodymium polyphosphate is the highest of all micropowders under investigation.Moreover,it is found that the nanocrystals reveal much higher relative sensitivity in respect to the microcrystalline counterparts.The highest sensitivity of LIR temperature sensing is found for LiPr(PO3)4 nanocrystals(35 nm grain size)in the whole temperature range,reaching 0.283%/K at 164 K.The impact of the average grain size on the sensitivity of LIR based thermometers of LiPr(PO3)4 nanocrystals was investigated.It is found that the reduction of the grain size from 145 to 35 nm results in the enhancement of the relative sensitivity from0.156 to 0.240%/K at 223 K.Additionally it is found that the high dopant concentration possesses favorable influence on the relative sensitivity of LiLa1-xPrx(PO3)4 nanocrystalline luminescent thermometers.展开更多
This paper analyses the issue of accelerated start-up of a marine steam turbine,which is an important problem because the start-up of a steam machine involves the combustion of fuel that is not transformed into useful...This paper analyses the issue of accelerated start-up of a marine steam turbine,which is an important problem because the start-up of a steam machine involves the combustion of fuel that is not transformed into useful energy.To find novel technologies that offer improvements in this aspect is essential due to restrictions on reducing ship emissions.Thus,the shorter the start-up time,the better for the environment and economy.High-pressure(HP)part of the turbine originally located on the Queen Elizabeth II unit was analysed.Advanced numerical calculations by thermal fluid-solid-interaction(Thermal FSI)were carried out.A series of simulations were performed for the accelerated start-up with controlled steam injection.A description of the chosen calculation methodology and the results obtained by simulation are included in this paper.The stress occurring during the accelerated start-up are approximately 40 MPa higher than those during the reference start-up.The relative elongations between the rotor and the hull during accelerated start-up reach a maximum value of 0.89 mm(0.83 mm for ultra-fast start-up).Reducing the steam turbine start-up time by 75%results in a 36.7 tons reduction in fuel consumption for start-up,resulting in an annual savings of 5372 USD.In conclusion,the concept proposed by the authors is safe,less expensive and does not affect the life of the turbine.In addition,results and applications from Siemens prove that additional injection of cooling steam is possible.展开更多
Background:The geriatric population is composed of persons over 65 years of age,and few studies are available on the dermatologic diseases in this group.Methods:Data on a total of 4099 geriatric patients admitted betw...Background:The geriatric population is composed of persons over 65 years of age,and few studies are available on the dermatologic diseases in this group.Methods:Data on a total of 4099 geriatric patients admitted between the years 1999-2003 were analyzed.Hospital-based patient registry records were used for data collection.The data were analyzed according to age,sex,and time of admittance.Results:The five most frequently encountered diseases in elderly patients were eczematous dermatitis,fungal infections,pruritus,and bacterial and viral infections.The most common disorders in males were fungal,bacterial,and viral infections,disorders of the feet,cutaneous ulcers,and vesiculo-bullous diseases,whereas,in females,they were immune-rheumatologic diseases and disorders of the mucous membranes.The five most frequently encountered diseases were significantly different in geriatric age subgroups.In the younger age group,pruritus,disorders due to sun exposure,and precancerous lesions and skin carcinomas were less common,whereas eczematous dermatitis was more common.The frequencies of some diseases showed significant seasonal variations.Infestations were more common in spring and summer,fungal infections were more common in summer but less so in winter,pruritus was more common in autumn but less so in spring,disorders due to sun exposure were more common in spring,and benign neoplasia were more common in autumn.In 2003,benign neoplasia,precancerous lesions and skin carcinomas,and immune-rheumatic disorders were more common,but vesicular and bullous diseases,fungal infections,and cutaneous lymphomas were less common when compared with the year 1999.Conclusions:This study provides important data on the frequency of dermatologic diseases in elderly patients,and shows variations in the frequency depending on age,gender,and season.We believe that this study will create awareness about the extent and patterns of dermatologic problems in geriatric patients.展开更多
Magnesium diboride(MgB_(2))magnets have the potential to be the next-generation liquid-helium-free magnet for magnetic resonance imaging(MRI)application due to their relatively high superconducting transition temperat...Magnesium diboride(MgB_(2))magnets have the potential to be the next-generation liquid-helium-free magnet for magnetic resonance imaging(MRI)application due to their relatively high superconducting transition temperature,high current density and low raw material cost compared with current commercial niobium-titanium(Nb-Ti)magnets.A typical superconducting magnet includes several coils.To produce an ultra-stable magnetic field for imaging in MRI,a superconducting electromagnet operating in a persistent mode is crucial.Superconducting coils of the electromagnet in MRI are short-circuited to operate in the persistent mode by connecting coils with superconducting joints.Per-sistent joints have been demonstrated for in-situ and ex-situ wires of both mono-and multi-filamentary structures,made predominantly by PIT techniques similar to those used in wire production.To realise further engagement of MgB_(2)in MRI applications,enhancing the performance of MgB_(2)superconducting joints is essential.This literature review summarises research and development on MgB_(2)superconducting joining technology.展开更多
Desired microstructure and surface integrity are critical to achieving the high performance of additively manufactured components.In the present work,the hybrid post-processes of magnetic abrasive finishing(MAF)and po...Desired microstructure and surface integrity are critical to achieving the high performance of additively manufactured components.In the present work,the hybrid post-processes of magnetic abrasive finishing(MAF)and post-heat treatment(HT)were applied to the additively manufactured Inconel718 superalloys.Their hybrid effects and influencing mechanism on the surface quality and mechanical properties of the additively manufactured samples have been studied comparatively.The results show that the MAF process effectively reduces the surface roughness by more than an order of magnitude due to the flexibility and geometric consistency of the magnetic particles and abrasives with the finished surfaces.The proper sequence of MAF and HT obtains enhanced mechanical properties for the homogenized-MAF-aged sample with the yield strength of 1147 MPa,the ultimate tensile strength of 1334 MPa,and the elongation of 22.9%,which exceeds the standard wrought material.The surface integrity,compressive residual stress field,and grain refinement induced by the MAF and subsequent aging heat treatment increase the cracking resistance and delay the fracture failure,which significantly benefits the mechanical properties.The MAF process combined with proper post-heat treatment provides an effective pathway to improve the mechanical properties of additively manufactured materials.展开更多
The luminescent rare earth(RE)complex based multifunctional nanocomposites offer new potential applications of multimodal imaging(magnetic resonance imaging(MRI),fluorescent bioimaging,etc.)that can be associated with...The luminescent rare earth(RE)complex based multifunctional nanocomposites offer new potential applications of multimodal imaging(magnetic resonance imaging(MRI),fluorescent bioimaging,etc.)that can be associated with therapeutic activities.In this study,we report some results obtained with novel multifunctional Fe3O4/Si-amine/Eu(NTA)3 nanocomposites that are composed of europium(Ⅲ)complex with 1-(2-naphthoyl)-3,3,3-trifluoroacetone ligands(NTA)(Eu(NTA)3)and superparamagnetic Fe3O4 nanoparticles.These nanocomposites were functionalized with an amine group for biomedicine application.The multifunctional Fe3O4/Si-amine/Eu(NTA)3 nanocomposites exhibit both good magnetic behavior of Fe3O4 nanoparticles as a core and strong fluorescent property of europium(Ⅲ)complex.Their characterizations were analyzed by XRD,SEM,EDX and FTIR spectra.The optical properties were studied in detail by UV-VIS spectra and luminescent emission spectra.The magnetic property was estimated by VMS.The effect of concentrations of luminescent Eu(NTA)3 complex on luminescent and magnetic properties is discussed.展开更多
Running is one of the most popular forms of exercise. Even though regular exercise is beneficial to human health, running is also often associated with an increased risk of injury. Lack of shock absorption in running ...Running is one of the most popular forms of exercise. Even though regular exercise is beneficial to human health, running is also often associated with an increased risk of injury. Lack of shock absorption in running shoes has often been stated as one of the main reasons for why running-related injuries have been on the increase. The aim of the present study was to assess the degree to which ground reaction forces (GRF) can be dissipated in the human leg in a barefoot subject, in connection with diverse physical activities. Acoustic myography (AMG), a non-invasive technique that records pressure waves from contracting muscles as well as the harmonic damping of ligaments, was applied to four anatomical sites on the subject’s leg, during barefoot walking, jogging, running and jumping. The data for walking on a hard surface show much lower ESTi<sup>TM</sup> parameters than those for the soft surface, and these lower values are observed mainly for sites 1 (toes;65%) and 2 (ankle;53%), respectively. AMG parameters for jogging reveal this gait to have very low ESTi<sup>TM</sup> parameters for site 1 and site 2 (ESTi 2 - 3), yet similar for both surfaces. The data for running on a hard and soft surface revealed much lower ESTi<sup>TM</sup> parameters (38%) than those for sites 3 (knee) and 4 (hip). The data from the big jump, reveal that on a hard surface, the lowest ESTi<sup>TM</sup> parameters were for sites 1 (toes;46%) and 2 (ankle;27%), compared to values on a soft surface. The speed with which GRFs were transmitted up the leg varied from site to site and also with the type of activity, ranging from undetectable to approx. 60 m/sec. The present study reveals that the ankle joint is exposed to the greatest forces during jumping and running. In addition, this study has confirmed that exercising on a hard surface does indeed increase the stress forces on the toes and ankles. It is interesting to note that the data reveal that toes and ankles absorb most of the GRF during running, while the knee and hip joint remain unaffected, although a more detailed study involving a larger number of subjects and shoe types is now needed.展开更多
Badly designed and fitted tack induces physiological stress responses in horses, and may compromise animal welfare. Moreover, horses, just like humans, comprise a series of interconnected myofascial lines. However, to...Badly designed and fitted tack induces physiological stress responses in horses, and may compromise animal welfare. Moreover, horses, just like humans, comprise a series of interconnected myofascial lines. However, to date there are no measurements of the effects of horse tack, such as bridles on muscle parameters. This study used acoustic myography to test whether two commercial anatomically designed and fitted bridles, have a measurable and positive effect on both equine muscle-function and performance. A Quantum bridle was tested on 12 Icelandic horses, whilst a Finesse bridle was tested on 8 Icelandic horses, and results compared with data from a standard bridle (n = 12) tested at the same time and under identical conditions. Sensors were placed on M. Brachiocephalicus and M. Splenius, and the horses exercised following a set protocol at three speeds. The results revealed statistically significant improvements in muscle performance as assessed by both the regularity of the recording at each speed, and the number of transient powerful contractions (spikes) for the anatomically designed and fitted bridles, compared with the standard bridle. It is concluded that the effect of anatomically designed bridles can not only be measured in the neck muscles of exercising horses, but that they appear to have a positive effect on muscle performance.展开更多
There is some discussion as to whether exercise-induced hyperthermia of the superficial digital flexor tendon (SDFT) affects tenocyte viability and pre-disposes to injury. Cold-therapy is commonly used as a preventati...There is some discussion as to whether exercise-induced hyperthermia of the superficial digital flexor tendon (SDFT) affects tenocyte viability and pre-disposes to injury. Cold-therapy is commonly used as a preventative measure and treatment for acute tendon injuries, but only a few studies have evaluated the effect of cold-therapy on metacarpal temperatures in the horse. For this reason, this study has measured skin surface temperatures after moderate exercise and after application of cold-therapy, and additionally monitored the duration of any effects. Four horses were recruited into a semi blinded controlled study with repeated measurements that involved lunged exercise for 16 minutes at moderate intensity. Skin surface temperature was measured using a thermographic camera before and after lunging, and every 40 minutes for two hours post cold-therapy. Cold-therapy was applied using a Jacks Whirlpool Boot with ice-water immersion at a level just distal to the carpus for 20 minutes. The right leg was treated, and the left leg was used as an untreated control. The experiment was conducted twice on all four horses. Moderate exercise resulted in an increase in skin surface temperature of 10<sup>°</sup>C. Application of cold-therapy for 20 minutes resulted in a reduction in skin surface temperature by 14<sup>°</sup>C. The effect of cold-therapy persisted for at least 40 minutes post treatment. It is concluded that exercise leads to an increase in skin surface temperature which is counteracted by the application of cold-therapy. These findings would seem to indicate that cold-therapy can be used after exercise to counteract hyperthermia within the metacarpal region of the horse’s leg.展开更多
The ability to calm horses affects both the safety and well-being of human-horse relationships. However, not many natural calmatives are known, nor the efficacy of these in supporting a state of calmness in horses. Th...The ability to calm horses affects both the safety and well-being of human-horse relationships. However, not many natural calmatives are known, nor the efficacy of these in supporting a state of calmness in horses. This study used both qualitative and quantitative methods to test whether aromatherapy has a measurable and calming effect on equine facial expression and a range of physiological parameters. Nine horses of different ages, genders and breeds were included in a crossover design with humidified essential oils to determine the calming effect of vetiver (<i>Vetiveria zizanioides</i>), spikenard (<i>Nardostachys jatamansi</i>) and roman chamomile (<i>Anthemis nobilis</i>) in relation to water (negative control) and lavender oil (positive control) in horses standing still. The results revealed significantly lowered heart rate (P < 0.05 - <0.001) and respiratory tidal volume (P < 0.05 - <0.001) for the tested essential oils, while spikenard oil was best at inducing a relaxed facial expression (60% of the full-time scale for 8 horses;75% of the full-time scale for 7 horses) and roman chamomile oil was statistically most successful at reducing the incidence of spontaneous muscle contractures in M. Temporalis (P < 0.001) and M. Cleidomastoideus (P < 0.05) compared to the other aromatherapy treatments. It is concluded that aromatherapy has both qualitative and quantitative effects on physiological parameters in static horses, and moreover, that essential oils appear to have a calming effect.展开更多
Background: Scientific procedures for addressing noseband fit and tightness, eliminating the risk of excessive and painful tightening, as well as quantitative measurements of pressures under the noseband while riding ...Background: Scientific procedures for addressing noseband fit and tightness, eliminating the risk of excessive and painful tightening, as well as quantitative measurements of pressures under the noseband while riding are either scarce or lacking. Purpose/Aim: To assess simple means of measuring pressure under different nosebands with a view to their adoption as scientific methodology. Method: Horses (n = 7) were fitted with five different bridles (A-E). Pressure distribution and intensity were measured using colour sensitive film (Fujifilm LLLW), assessing the level of pressure and distribution across the surface of the nosebands, as assessed and ranked by independent assessors. A CURO system was also used to measure pressure in real-time under nosebands whilst riding. Results: The colour-sensitive film for D & B were ranked 1st and 2nd, respectively. Regularity of pressure overall showed a statistical difference between nosebands (A & B significantly more unregular than the others). Pressure measurements revealed significantly different means (all P Conclusions: Pressures under nosebands can reach levels that appear capable of inflicting tissue damage, hence bridles and nosebands should be assessed using scientific methodology and not based on arbitrary and subjective criteria, as is currently the case.展开更多
文摘Photonic-engineered passive radiative cooling built into decorative climate-controlled enclosures reduces the active power consumption of the existing enclosure without sacrificing its aesthetics.
文摘The histogensis of extramammary Paget's disease has not been solved and remained controversial. Eight cases of extramammary Paget's disease of geni-tocrural region were investigated by alcian blue and PAS stain and immunoreaction of anti-CEA and anti-keratin. It was found that the pattern and intensity of alcian blue, PAS staining were identical for Paget cells and secretory cells of apocrine sweat gland; and CEA immunoreactivity was uniformly observed in both Paget cells and eccrine sweat gland. The keratin immunoreaction was positive in keratinocytes, apocrine and eccrine sweat gland, whereas Paget cells were negative. These results suggested that Paget cells of extramammary Paget's disease could be derived from multipotential epidermal germ cells.
文摘To formulate the optimal strategy of combatting bacterial biofilms,in this review we update current knowledge on the growing problem of biofilm formation and its resistance to antibiotics which has spurred the search for new strategies to deal with this complication.Based on recent findings,the role of bacteriophages in the prevention and elimination of biofilm-related infections has been emphasized.In vitro,ex vivo and in vivo biofilm treatment models with single bacteriophages or phage cocktails have been compared.A combined use of bacteriophages with antibiotics in vitro or in vivo confirms earlier reports of the synergistic effect of these agents in improving biofilm removal.Furthermore,studies on the application of phage-derived lysins in vitro,ex vivo or in vivo against biofilm-related infections are encouraging.The strategy of combined use of phage and antibiotics seems to be different from using lysins and antibiotics.These findings suggest that phages and lysins alone or in combination with antibiotics may be an efficient weapon against biofilm formation in vivo and ex vivo,which could be useful in formulating novel strategies to combat bacterial infections.Those findings proved to be relevant in the prevention and destruction of biofilms occurring during urinary tract infections,orthopedic implant-related infections,periodontal and peri-implant infections.In conclusion,it appears that most efficient strategy of eliminating biofilms involves phages or lysins in combination with antibiotics,but the optimal scheme of their administration requires further studies.
基金supported by the Bulgarian National Science Fund(ContractдH09/5/2016)the CONACYT PDCPN 1216 and the University of Turin(Ricerca Locale 2016-2017)
文摘The utilization of pure hydrogen as an energy source in fuel cells gave rise to renewed interest in developing active and stable water-gas shift catalysts. Gold catalysts have proven to be very efficient for water-gas shift reaction at low temperature. The aim of the present study was to investigate the effect of:(i) different preparation methods(impregnation and coprecipitation) to obtain a modified ceria support,and(ii) the amount of Y_2 O_3(1.0 wt%, 2.5 wt%, 5.0 wt% and 7.5 wt%) as dopant on the water-gas shift activity of Au/CeO_2 catalysts. An extended characterization by means of S_(BET), XRD, HRTEM/HAADF, FTIR,H_2-TPR and CO-TPR measurements in combination with careful evaluation of the catalyst behavior allowed to shed light on the parameters governing the water-gas shift activity. The catalysts show very high activity(>90% CO conversion) in the temperature range 180-220 ℃,with a slightly better performance of the gold catalysts on supports prepared by impregnation. The decreased activity with increasing Y_2 O_3 concentration is related to the hindering of oxygen mobility due to ordering of surface oxygen vacancies in vicinity of segregated Y^(3+). The effect of catalyst pre-treatments and the stability of the best performing samples were examined as well.
基金supported in part by the National Science Center (Poland) under grant No. 2018/31/B/ST8/00942。
文摘Deformation behavior as well as microstructural evolutions of a rolled AZ31 magnesium alloy with and without pre-existing extension twins were studied using compression tests which performed along different orientations at a temperature range of 25–350 ℃. The results implied that the initial texture not only influence the evolution of flow stress, but also change the size and fraction of recrystallized grains.In contrast to samples parallel to rolling and transverse directions, compression along normal direction resulted in a respectful softening at 150 ℃. The largest size and fraction of new grains at 250 ℃ were recorded after deformation along rolling direction, while the maximum flow softening was observed during deformation along normal direction. The anisotropy in microstructural evolutions was still retained at 350 ℃. Pre-existing twins could reduce the anisotropy of material in respect of flow stress as well as DRX progression, where TD sample showed the lowest DRX fraction at 250 ℃. Quaternion misorientation data obtained from EBSD analysis of pretwinned material implied that initial texture could not significantly influence final texture. A different misorientation distribution was realized after deformation of pretwinned material along ND and RD directions.
基金Project supported by the Ministry of Higher Education and Scientific Research in Tunisia(99/UR/07-03)
文摘In this article,varied praseodymium polyphosphate hosts:MI(Li,Na K)Pr(PO3)4 microcrystals and LiLa1-xPrx(PO3)4(x = 0.01 ^-1)nanocrystals were successfully synthesized by the flux method and the coprecipitation technique,respectively.The size of stoichiometric nanocrystals of LiPr(PO3)4 was tuned by the te mpe rature of thermal treatment in range of 35-145 nm.In order to dete rmine the most suitable material for the non-contact optical thermometric applications,the temperature sensing measurements were carried out by using luminescence intensity ratio(LIR)of emission bands corresponding to the ^3 P1→ ^3H5 and ^3P0→ ^3 H5 electronic transitions of Pr3+ ions into the 123-423 K temperature range.The influence of the host material composition of MⅠ(Li,Na,K)Pr(PO3)4 microcrystals on the sensitivity of luminescent thermometers was studied.It is found that the sensitivity of lithium praseodymium polyphosphate is the highest of all micropowders under investigation.Moreover,it is found that the nanocrystals reveal much higher relative sensitivity in respect to the microcrystalline counterparts.The highest sensitivity of LIR temperature sensing is found for LiPr(PO3)4 nanocrystals(35 nm grain size)in the whole temperature range,reaching 0.283%/K at 164 K.The impact of the average grain size on the sensitivity of LIR based thermometers of LiPr(PO3)4 nanocrystals was investigated.It is found that the reduction of the grain size from 145 to 35 nm results in the enhancement of the relative sensitivity from0.156 to 0.240%/K at 223 K.Additionally it is found that the high dopant concentration possesses favorable influence on the relative sensitivity of LiLa1-xPrx(PO3)4 nanocrystalline luminescent thermometers.
文摘This paper analyses the issue of accelerated start-up of a marine steam turbine,which is an important problem because the start-up of a steam machine involves the combustion of fuel that is not transformed into useful energy.To find novel technologies that offer improvements in this aspect is essential due to restrictions on reducing ship emissions.Thus,the shorter the start-up time,the better for the environment and economy.High-pressure(HP)part of the turbine originally located on the Queen Elizabeth II unit was analysed.Advanced numerical calculations by thermal fluid-solid-interaction(Thermal FSI)were carried out.A series of simulations were performed for the accelerated start-up with controlled steam injection.A description of the chosen calculation methodology and the results obtained by simulation are included in this paper.The stress occurring during the accelerated start-up are approximately 40 MPa higher than those during the reference start-up.The relative elongations between the rotor and the hull during accelerated start-up reach a maximum value of 0.89 mm(0.83 mm for ultra-fast start-up).Reducing the steam turbine start-up time by 75%results in a 36.7 tons reduction in fuel consumption for start-up,resulting in an annual savings of 5372 USD.In conclusion,the concept proposed by the authors is safe,less expensive and does not affect the life of the turbine.In addition,results and applications from Siemens prove that additional injection of cooling steam is possible.
文摘Background:The geriatric population is composed of persons over 65 years of age,and few studies are available on the dermatologic diseases in this group.Methods:Data on a total of 4099 geriatric patients admitted between the years 1999-2003 were analyzed.Hospital-based patient registry records were used for data collection.The data were analyzed according to age,sex,and time of admittance.Results:The five most frequently encountered diseases in elderly patients were eczematous dermatitis,fungal infections,pruritus,and bacterial and viral infections.The most common disorders in males were fungal,bacterial,and viral infections,disorders of the feet,cutaneous ulcers,and vesiculo-bullous diseases,whereas,in females,they were immune-rheumatologic diseases and disorders of the mucous membranes.The five most frequently encountered diseases were significantly different in geriatric age subgroups.In the younger age group,pruritus,disorders due to sun exposure,and precancerous lesions and skin carcinomas were less common,whereas eczematous dermatitis was more common.The frequencies of some diseases showed significant seasonal variations.Infestations were more common in spring and summer,fungal infections were more common in summer but less so in winter,pruritus was more common in autumn but less so in spring,disorders due to sun exposure were more common in spring,and benign neoplasia were more common in autumn.In 2003,benign neoplasia,precancerous lesions and skin carcinomas,and immune-rheumatic disorders were more common,but vesicular and bullous diseases,fungal infections,and cutaneous lymphomas were less common when compared with the year 1999.Conclusions:This study provides important data on the frequency of dermatologic diseases in elderly patients,and shows variations in the frequency depending on age,gender,and season.We believe that this study will create awareness about the extent and patterns of dermatologic problems in geriatric patients.
基金thankful for the support from the Australian Research Council(ARC)Linkage Project(LP200200689).
文摘Magnesium diboride(MgB_(2))magnets have the potential to be the next-generation liquid-helium-free magnet for magnetic resonance imaging(MRI)application due to their relatively high superconducting transition temperature,high current density and low raw material cost compared with current commercial niobium-titanium(Nb-Ti)magnets.A typical superconducting magnet includes several coils.To produce an ultra-stable magnetic field for imaging in MRI,a superconducting electromagnet operating in a persistent mode is crucial.Superconducting coils of the electromagnet in MRI are short-circuited to operate in the persistent mode by connecting coils with superconducting joints.Per-sistent joints have been demonstrated for in-situ and ex-situ wires of both mono-and multi-filamentary structures,made predominantly by PIT techniques similar to those used in wire production.To realise further engagement of MgB_(2)in MRI applications,enhancing the performance of MgB_(2)superconducting joints is essential.This literature review summarises research and development on MgB_(2)superconducting joining technology.
基金financial support from the Fundamental Research Funds for the Central Universities in China(No.2021CDJQY-024)the Research Project from Chongqing Key Laboratory of Metal Additive Manufacturing(3D Printing)in Chongqing University(No.02090011044158)the National Natural Science Foundation of China(No.51975073)。
文摘Desired microstructure and surface integrity are critical to achieving the high performance of additively manufactured components.In the present work,the hybrid post-processes of magnetic abrasive finishing(MAF)and post-heat treatment(HT)were applied to the additively manufactured Inconel718 superalloys.Their hybrid effects and influencing mechanism on the surface quality and mechanical properties of the additively manufactured samples have been studied comparatively.The results show that the MAF process effectively reduces the surface roughness by more than an order of magnitude due to the flexibility and geometric consistency of the magnetic particles and abrasives with the finished surfaces.The proper sequence of MAF and HT obtains enhanced mechanical properties for the homogenized-MAF-aged sample with the yield strength of 1147 MPa,the ultimate tensile strength of 1334 MPa,and the elongation of 22.9%,which exceeds the standard wrought material.The surface integrity,compressive residual stress field,and grain refinement induced by the MAF and subsequent aging heat treatment increase the cracking resistance and delay the fracture failure,which significantly benefits the mechanical properties.The MAF process combined with proper post-heat treatment provides an effective pathway to improve the mechanical properties of additively manufactured materials.
基金Project supported by Vietnam Academy of Science and Technology(VAST03.03/18-19)
文摘The luminescent rare earth(RE)complex based multifunctional nanocomposites offer new potential applications of multimodal imaging(magnetic resonance imaging(MRI),fluorescent bioimaging,etc.)that can be associated with therapeutic activities.In this study,we report some results obtained with novel multifunctional Fe3O4/Si-amine/Eu(NTA)3 nanocomposites that are composed of europium(Ⅲ)complex with 1-(2-naphthoyl)-3,3,3-trifluoroacetone ligands(NTA)(Eu(NTA)3)and superparamagnetic Fe3O4 nanoparticles.These nanocomposites were functionalized with an amine group for biomedicine application.The multifunctional Fe3O4/Si-amine/Eu(NTA)3 nanocomposites exhibit both good magnetic behavior of Fe3O4 nanoparticles as a core and strong fluorescent property of europium(Ⅲ)complex.Their characterizations were analyzed by XRD,SEM,EDX and FTIR spectra.The optical properties were studied in detail by UV-VIS spectra and luminescent emission spectra.The magnetic property was estimated by VMS.The effect of concentrations of luminescent Eu(NTA)3 complex on luminescent and magnetic properties is discussed.
文摘Running is one of the most popular forms of exercise. Even though regular exercise is beneficial to human health, running is also often associated with an increased risk of injury. Lack of shock absorption in running shoes has often been stated as one of the main reasons for why running-related injuries have been on the increase. The aim of the present study was to assess the degree to which ground reaction forces (GRF) can be dissipated in the human leg in a barefoot subject, in connection with diverse physical activities. Acoustic myography (AMG), a non-invasive technique that records pressure waves from contracting muscles as well as the harmonic damping of ligaments, was applied to four anatomical sites on the subject’s leg, during barefoot walking, jogging, running and jumping. The data for walking on a hard surface show much lower ESTi<sup>TM</sup> parameters than those for the soft surface, and these lower values are observed mainly for sites 1 (toes;65%) and 2 (ankle;53%), respectively. AMG parameters for jogging reveal this gait to have very low ESTi<sup>TM</sup> parameters for site 1 and site 2 (ESTi 2 - 3), yet similar for both surfaces. The data for running on a hard and soft surface revealed much lower ESTi<sup>TM</sup> parameters (38%) than those for sites 3 (knee) and 4 (hip). The data from the big jump, reveal that on a hard surface, the lowest ESTi<sup>TM</sup> parameters were for sites 1 (toes;46%) and 2 (ankle;27%), compared to values on a soft surface. The speed with which GRFs were transmitted up the leg varied from site to site and also with the type of activity, ranging from undetectable to approx. 60 m/sec. The present study reveals that the ankle joint is exposed to the greatest forces during jumping and running. In addition, this study has confirmed that exercising on a hard surface does indeed increase the stress forces on the toes and ankles. It is interesting to note that the data reveal that toes and ankles absorb most of the GRF during running, while the knee and hip joint remain unaffected, although a more detailed study involving a larger number of subjects and shoe types is now needed.
文摘Badly designed and fitted tack induces physiological stress responses in horses, and may compromise animal welfare. Moreover, horses, just like humans, comprise a series of interconnected myofascial lines. However, to date there are no measurements of the effects of horse tack, such as bridles on muscle parameters. This study used acoustic myography to test whether two commercial anatomically designed and fitted bridles, have a measurable and positive effect on both equine muscle-function and performance. A Quantum bridle was tested on 12 Icelandic horses, whilst a Finesse bridle was tested on 8 Icelandic horses, and results compared with data from a standard bridle (n = 12) tested at the same time and under identical conditions. Sensors were placed on M. Brachiocephalicus and M. Splenius, and the horses exercised following a set protocol at three speeds. The results revealed statistically significant improvements in muscle performance as assessed by both the regularity of the recording at each speed, and the number of transient powerful contractions (spikes) for the anatomically designed and fitted bridles, compared with the standard bridle. It is concluded that the effect of anatomically designed bridles can not only be measured in the neck muscles of exercising horses, but that they appear to have a positive effect on muscle performance.
文摘There is some discussion as to whether exercise-induced hyperthermia of the superficial digital flexor tendon (SDFT) affects tenocyte viability and pre-disposes to injury. Cold-therapy is commonly used as a preventative measure and treatment for acute tendon injuries, but only a few studies have evaluated the effect of cold-therapy on metacarpal temperatures in the horse. For this reason, this study has measured skin surface temperatures after moderate exercise and after application of cold-therapy, and additionally monitored the duration of any effects. Four horses were recruited into a semi blinded controlled study with repeated measurements that involved lunged exercise for 16 minutes at moderate intensity. Skin surface temperature was measured using a thermographic camera before and after lunging, and every 40 minutes for two hours post cold-therapy. Cold-therapy was applied using a Jacks Whirlpool Boot with ice-water immersion at a level just distal to the carpus for 20 minutes. The right leg was treated, and the left leg was used as an untreated control. The experiment was conducted twice on all four horses. Moderate exercise resulted in an increase in skin surface temperature of 10<sup>°</sup>C. Application of cold-therapy for 20 minutes resulted in a reduction in skin surface temperature by 14<sup>°</sup>C. The effect of cold-therapy persisted for at least 40 minutes post treatment. It is concluded that exercise leads to an increase in skin surface temperature which is counteracted by the application of cold-therapy. These findings would seem to indicate that cold-therapy can be used after exercise to counteract hyperthermia within the metacarpal region of the horse’s leg.
文摘The ability to calm horses affects both the safety and well-being of human-horse relationships. However, not many natural calmatives are known, nor the efficacy of these in supporting a state of calmness in horses. This study used both qualitative and quantitative methods to test whether aromatherapy has a measurable and calming effect on equine facial expression and a range of physiological parameters. Nine horses of different ages, genders and breeds were included in a crossover design with humidified essential oils to determine the calming effect of vetiver (<i>Vetiveria zizanioides</i>), spikenard (<i>Nardostachys jatamansi</i>) and roman chamomile (<i>Anthemis nobilis</i>) in relation to water (negative control) and lavender oil (positive control) in horses standing still. The results revealed significantly lowered heart rate (P < 0.05 - <0.001) and respiratory tidal volume (P < 0.05 - <0.001) for the tested essential oils, while spikenard oil was best at inducing a relaxed facial expression (60% of the full-time scale for 8 horses;75% of the full-time scale for 7 horses) and roman chamomile oil was statistically most successful at reducing the incidence of spontaneous muscle contractures in M. Temporalis (P < 0.001) and M. Cleidomastoideus (P < 0.05) compared to the other aromatherapy treatments. It is concluded that aromatherapy has both qualitative and quantitative effects on physiological parameters in static horses, and moreover, that essential oils appear to have a calming effect.
文摘Background: Scientific procedures for addressing noseband fit and tightness, eliminating the risk of excessive and painful tightening, as well as quantitative measurements of pressures under the noseband while riding are either scarce or lacking. Purpose/Aim: To assess simple means of measuring pressure under different nosebands with a view to their adoption as scientific methodology. Method: Horses (n = 7) were fitted with five different bridles (A-E). Pressure distribution and intensity were measured using colour sensitive film (Fujifilm LLLW), assessing the level of pressure and distribution across the surface of the nosebands, as assessed and ranked by independent assessors. A CURO system was also used to measure pressure in real-time under nosebands whilst riding. Results: The colour-sensitive film for D & B were ranked 1st and 2nd, respectively. Regularity of pressure overall showed a statistical difference between nosebands (A & B significantly more unregular than the others). Pressure measurements revealed significantly different means (all P Conclusions: Pressures under nosebands can reach levels that appear capable of inflicting tissue damage, hence bridles and nosebands should be assessed using scientific methodology and not based on arbitrary and subjective criteria, as is currently the case.
