Objective: This study was performed with the purpose a report clinical cases involving condylar position and Nóbilo’s sliding plates. Background: Patients may present temporomandibular disorder (TMD), which is c...Objective: This study was performed with the purpose a report clinical cases involving condylar position and Nóbilo’s sliding plates. Background: Patients may present temporomandibular disorder (TMD), which is characterized by pain in masticatory muscles, temporomandibular joints and limited mandible movements. Treatment involving oral rehabilitation with the use of complete dentures with Nóbilo’s sliding plates has been an alternative for the treatment of TMD. Materials and Methods: Nine patients with a history of TMD signs and symptoms (RDC/TMD)—in particular, muscular and articular pain—received pain evaluations, mandibular movement analysis, transcranial radiography and an electromyographic analysis of the masseter and temporalis muscles before and after the use of complete dentures with Nóbilo’s sliding plates. Results: After treatment, the patients had reduced painful symptoms, an increase in mandibular movement and adequate electromyographic activity. The normalized EMG data were ta-bulated and analyzed statistically using SPSS version 17.0 for Windows (SPSS Inc., Chicago, IL, USA), and the values were compared by umpaired independent Student’s t-test. Conclusion: The use of Nóbilo’s sliding plates promoted improvements in electromyographic activity, muscular pain and man-dibular movement.展开更多
The basic formulation of Al2O3- C slide plates was65%( in mass,the same hereinafter) white fused corundum particles,25% white fused corundum fines,6% active α-Al2O3 micropowder,4% carbon black and flake graphite, a...The basic formulation of Al2O3- C slide plates was65%( in mass,the same hereinafter) white fused corundum particles,25% white fused corundum fines,6% active α-Al2O3 micropowder,4% carbon black and flake graphite, and additional 4% phenolic resin.Based on this formulation,3% Al powder,3% Si powder,and 3% Al + 3% Si powder were used to substitute equivalent white corundum fines to improve the hot mechanical properties of Al2O3- C slide plates. The specimens with dimensions of 140 mm × 25 mm × 25 mm were pressed at 150 MPa,dried at 200 ℃ for 24 h,and hot treated at 1 400 ℃ for 3 h in carbon embedded condition. Then hot modulus of rupture and thermal shock resistance of the specimens were tested and the phase compositions and microstructure were analyzed. The results show that specimen with 3% Al powder has the higher hot modulus of rupture but lower residual modulus of rupture after thermal shock than the specimen with3% Si powder; the specimen with 3% Al + 3% Si powders exhibits the highest hot modulus of rupture and the best thermal shock resistance; the change of mechanical property is closely related with the in-situ formed nonoxides: AlN in the form of bars is formed in specimens with Al powder; fibrous SiC whiskers are formed in specimens with Si powder; in the specimens with both Al and Sipowders,besides AlN and SiC whiskers,hexagonal tabular SiAlON is in-situ synthesized,which interlocks with each other.展开更多
The zirconia ceramic ring was prepared using fused monoclinic zirconia as main starting material, adopting composite stabilizer of magnesia, yttria and calcium nitrate, and applying recombination technology of traditi...The zirconia ceramic ring was prepared using fused monoclinic zirconia as main starting material, adopting composite stabilizer of magnesia, yttria and calcium nitrate, and applying recombination technology of traditional refractories and ceramics. Effect of the preparation process on material properties was comparatively studied, and the microstructure and phase composition were analyzed. The results show that adopting the high-speed mixing granulation process and the appropriate heat treatment can realize the control on the phase composition and microstructure, the zirconia ceramic ring with good thermal shock resitance and mechanical properties can be prepared.展开更多
Several kinds of slide nozzle plate such as A12O3-C-ZrO2, MgO, Al2O3, Spinel-C and A12O3-C SN plate for high oxygen steel used in BaoSteel have been analysed, the appearance and size of the SN plate after using have b...Several kinds of slide nozzle plate such as A12O3-C-ZrO2, MgO, Al2O3, Spinel-C and A12O3-C SN plate for high oxygen steel used in BaoSteel have been analysed, the appearance and size of the SN plate after using have been measured. The Al2O3-C SN plate has longer service life in casting high oxygen steel, and the wear mechanism of different SN plates is discussed.展开更多
Magnesium aluminate spinel -corundum composite was prepared with waste slide plate and magnesia carbon brick. Microstructure and sintering ability of as-prepared magnesium aluminate spinel -corundum composite were inv...Magnesium aluminate spinel -corundum composite was prepared with waste slide plate and magnesia carbon brick. Microstructure and sintering ability of as-prepared magnesium aluminate spinel -corundum composite were investigated with XRD, SEM, and DSC/TG. With the addition of waste slide plate increasing or synthesis tem- perature rising, the bulk density of the specimen increases and the apparent porosity decreases, but the crystallinity of the specimen decreases and the magnesium alaminate spinel phase increases. The obtained composite contains 72% spinel and 26% corundum. Primary phase and secondary phase are bonded by glass phase. The results show that it is feasible to synthesis magnesium aluminate spinel - corundum material with waste slide plate and magnesia carbon brick.展开更多
Al2 O3 - SiC - SiAION composite specimens have been prepared using fused alumina, ultra fine α-Al2O3, Si and Al powders as starting materials and liquid phenol formaldehyde resin as binder and firing at 1 500 ℃ for ...Al2 O3 - SiC - SiAION composite specimens have been prepared using fused alumina, ultra fine α-Al2O3, Si and Al powders as starting materials and liquid phenol formaldehyde resin as binder and firing at 1 500 ℃ for 3 h in carbon embedded condition. Thermo-mechanical properties of Al2 O3 - SiC - SiAlON composites have been studied. The results show : ( 1 ) Al2 O3 - SiC - SiAION composites can be prepared and sintered at 1 500 ℃ under carbon embedded condition. When Si/Al ratio is 8/0 and 7/1, the prepared composite is Al2O3 - SiC - O' -SiAlON; when Si/Al ratio is 5/3 and 3/5, the pre- pared composite is Al2 O3 - SiC - β-SiAION. ( 2 ) The composites possess high temperature strength properties. Hot modulus of rupture at 1 400 ℃ is 10 - 30 MPa. They are in elastic range up to 1 000 ℃, after which plastic deformation is observed; even at 1 400 ℃, amount of deformation is relatively low. (3) The com- posites possess good thermal shock resistance, their resid- ual strength ratio (AT = 1 100 ℃ ) is 65% - 80%. (4) The marked improvement in thermo-mechanical properties of Al2O3 - SiC - SiAlON composites may be at- tributed to the in-situ formation of SiC, SiAlON and AIN, the fibrous SiC, columnar SiAlON and tabular-like AlN fill in the corundum skeleton structure creating strengthening and toughening effects.展开更多
Effects of particle size (A:d50 = 336. 9 μm, B:d50 =123.5μm, C: d50=19.5 μm, D: dso=2.21μm) and content (1 wt% , 3 wt% , 5 wt% , 7 wt% ) of silicon powder on cold crushing strength (CCS) , pore size dis...Effects of particle size (A:d50 = 336. 9 μm, B:d50 =123.5μm, C: d50=19.5 μm, D: dso=2.21μm) and content (1 wt% , 3 wt% , 5 wt% , 7 wt% ) of silicon powder on cold crushing strength (CCS) , pore size distribution and microstructure of Al2O3 - ZrO2 - C refractories coked at high temperature had been investigated by means of mercury porosimeter, SEM, EDS, tic. The results indicated that particle size and content of silicon powder affected the cold crushing strength of coked specimens. It increased with the addition of silicon powder and its finer particle size. However, it decreased greatly when using too fine silicon powder. The particle size and content of silicon powder also impacted the phase evolution and microstructure of coked specimens, much more β-SiC whiskers constituted network structure and well distributed in specimens with reduction of their slenderness ratios when finer silicon powder was added, corresponding to that, the specimens' pore size distribution range became narrower with smaller pore diameter, but β-SiC whiskers were distributed sparsely and the specific pore volume of small pores increased when much finer powder was added. It was worthly mentioned that some nitride could form in specimens with addition of appropriate particle size and content of silicon powder.展开更多
基金This study was supported by the Foundation for Research Support of São Paulo (FAPESP).
文摘Objective: This study was performed with the purpose a report clinical cases involving condylar position and Nóbilo’s sliding plates. Background: Patients may present temporomandibular disorder (TMD), which is characterized by pain in masticatory muscles, temporomandibular joints and limited mandible movements. Treatment involving oral rehabilitation with the use of complete dentures with Nóbilo’s sliding plates has been an alternative for the treatment of TMD. Materials and Methods: Nine patients with a history of TMD signs and symptoms (RDC/TMD)—in particular, muscular and articular pain—received pain evaluations, mandibular movement analysis, transcranial radiography and an electromyographic analysis of the masseter and temporalis muscles before and after the use of complete dentures with Nóbilo’s sliding plates. Results: After treatment, the patients had reduced painful symptoms, an increase in mandibular movement and adequate electromyographic activity. The normalized EMG data were ta-bulated and analyzed statistically using SPSS version 17.0 for Windows (SPSS Inc., Chicago, IL, USA), and the values were compared by umpaired independent Student’s t-test. Conclusion: The use of Nóbilo’s sliding plates promoted improvements in electromyographic activity, muscular pain and man-dibular movement.
文摘The basic formulation of Al2O3- C slide plates was65%( in mass,the same hereinafter) white fused corundum particles,25% white fused corundum fines,6% active α-Al2O3 micropowder,4% carbon black and flake graphite, and additional 4% phenolic resin.Based on this formulation,3% Al powder,3% Si powder,and 3% Al + 3% Si powder were used to substitute equivalent white corundum fines to improve the hot mechanical properties of Al2O3- C slide plates. The specimens with dimensions of 140 mm × 25 mm × 25 mm were pressed at 150 MPa,dried at 200 ℃ for 24 h,and hot treated at 1 400 ℃ for 3 h in carbon embedded condition. Then hot modulus of rupture and thermal shock resistance of the specimens were tested and the phase compositions and microstructure were analyzed. The results show that specimen with 3% Al powder has the higher hot modulus of rupture but lower residual modulus of rupture after thermal shock than the specimen with3% Si powder; the specimen with 3% Al + 3% Si powders exhibits the highest hot modulus of rupture and the best thermal shock resistance; the change of mechanical property is closely related with the in-situ formed nonoxides: AlN in the form of bars is formed in specimens with Al powder; fibrous SiC whiskers are formed in specimens with Si powder; in the specimens with both Al and Sipowders,besides AlN and SiC whiskers,hexagonal tabular SiAlON is in-situ synthesized,which interlocks with each other.
文摘The zirconia ceramic ring was prepared using fused monoclinic zirconia as main starting material, adopting composite stabilizer of magnesia, yttria and calcium nitrate, and applying recombination technology of traditional refractories and ceramics. Effect of the preparation process on material properties was comparatively studied, and the microstructure and phase composition were analyzed. The results show that adopting the high-speed mixing granulation process and the appropriate heat treatment can realize the control on the phase composition and microstructure, the zirconia ceramic ring with good thermal shock resitance and mechanical properties can be prepared.
文摘Several kinds of slide nozzle plate such as A12O3-C-ZrO2, MgO, Al2O3, Spinel-C and A12O3-C SN plate for high oxygen steel used in BaoSteel have been analysed, the appearance and size of the SN plate after using have been measured. The Al2O3-C SN plate has longer service life in casting high oxygen steel, and the wear mechanism of different SN plates is discussed.
文摘Magnesium aluminate spinel -corundum composite was prepared with waste slide plate and magnesia carbon brick. Microstructure and sintering ability of as-prepared magnesium aluminate spinel -corundum composite were investigated with XRD, SEM, and DSC/TG. With the addition of waste slide plate increasing or synthesis tem- perature rising, the bulk density of the specimen increases and the apparent porosity decreases, but the crystallinity of the specimen decreases and the magnesium alaminate spinel phase increases. The obtained composite contains 72% spinel and 26% corundum. Primary phase and secondary phase are bonded by glass phase. The results show that it is feasible to synthesis magnesium aluminate spinel - corundum material with waste slide plate and magnesia carbon brick.
基金the financial support of Science Fund for International Cooperation Project(No.152102410014)the Education Department of Henan Province Foundation(14A430030)Research Foundation of Zhengzhou City(131PPTGG-409-3)
文摘Al2 O3 - SiC - SiAION composite specimens have been prepared using fused alumina, ultra fine α-Al2O3, Si and Al powders as starting materials and liquid phenol formaldehyde resin as binder and firing at 1 500 ℃ for 3 h in carbon embedded condition. Thermo-mechanical properties of Al2 O3 - SiC - SiAlON composites have been studied. The results show : ( 1 ) Al2 O3 - SiC - SiAION composites can be prepared and sintered at 1 500 ℃ under carbon embedded condition. When Si/Al ratio is 8/0 and 7/1, the prepared composite is Al2O3 - SiC - O' -SiAlON; when Si/Al ratio is 5/3 and 3/5, the pre- pared composite is Al2 O3 - SiC - β-SiAION. ( 2 ) The composites possess high temperature strength properties. Hot modulus of rupture at 1 400 ℃ is 10 - 30 MPa. They are in elastic range up to 1 000 ℃, after which plastic deformation is observed; even at 1 400 ℃, amount of deformation is relatively low. (3) The com- posites possess good thermal shock resistance, their resid- ual strength ratio (AT = 1 100 ℃ ) is 65% - 80%. (4) The marked improvement in thermo-mechanical properties of Al2O3 - SiC - SiAlON composites may be at- tributed to the in-situ formation of SiC, SiAlON and AIN, the fibrous SiC, columnar SiAlON and tabular-like AlN fill in the corundum skeleton structure creating strengthening and toughening effects.
文摘Effects of particle size (A:d50 = 336. 9 μm, B:d50 =123.5μm, C: d50=19.5 μm, D: dso=2.21μm) and content (1 wt% , 3 wt% , 5 wt% , 7 wt% ) of silicon powder on cold crushing strength (CCS) , pore size distribution and microstructure of Al2O3 - ZrO2 - C refractories coked at high temperature had been investigated by means of mercury porosimeter, SEM, EDS, tic. The results indicated that particle size and content of silicon powder affected the cold crushing strength of coked specimens. It increased with the addition of silicon powder and its finer particle size. However, it decreased greatly when using too fine silicon powder. The particle size and content of silicon powder also impacted the phase evolution and microstructure of coked specimens, much more β-SiC whiskers constituted network structure and well distributed in specimens with reduction of their slenderness ratios when finer silicon powder was added, corresponding to that, the specimens' pore size distribution range became narrower with smaller pore diameter, but β-SiC whiskers were distributed sparsely and the specific pore volume of small pores increased when much finer powder was added. It was worthly mentioned that some nitride could form in specimens with addition of appropriate particle size and content of silicon powder.