Groove-rolling as an alternative process to fabricate Bi-2212 wires for practical applications

Bi2Sr2CaCu2O8+x (Bi-2212) superconducting long-length wires are mainly limited in obtaining high critical currents densities (JC) by the internal gas pressure generated during the heat treatment, which expands the wire diameter and dedensifies the superconducting filaments. Several ways have been developed to increase the density of the superconducting filaments and therefore decreasing the bubble density: much higher critical currents have been reached always acting on the final as-drawn wires. We here try to pursue the same goal of having a denser wire by acting on the deformation technique, through a partial use of the groove-rolling at different wire processing stages. Such technique has a larger powders compaction power, is straightforwardly adaptable to long length samples, and allows the fabrication of samples with round, square or rectangular shape depending on the application requirements. In this paper we demonstrate the capability of this technique to increase the density in Bi-2212 wires which leads to a three-fold increase in Jc with respect to drawn wires, making this approach very promising for fabricating Bi-2212 wires for high magnetic field magnets, i.e. above 25 T

Microhardness of different resin cement shades inside the root canal

Objectives: To compare microhardness along the root canal post space of two resin cements in different shades and a dual-cure resin core material. Study D esign: Root canals of 21 bovine incisors were prepared for post space. Translucent posts (X?Post, Dentsply DeTrey) were luted using one the following resin luting agent: Calibra (Dentsply DeTrey) in Translucent, Medium and Opaque shades, RelyX Unicem (3M ESPE) in Translucent, A2 and A3 shades and the dual-cure resin core material Core?X flow. All materials were applied according to manufacturers? instructions and were all photopolymerized (Bluephase LED unit, Ivoclar Vivadent, 40s). After 24 hours, roots were transversally cut into 9 slices 1 mm thick from the coronal to apical extremes, three corresponding to each root third. Then, VHNs were recorded (100gf, 30 s) on the resin luting materials along the adhesive interface in all sections. Data were analyzed by two- way ANOVA and SNK tests (?=0.05). Results: A significant influence on microhardness of resin luting material in their respective shades (p<0.001), root third (p<0.001) and interactions between them was detected (p<0.001). RelyX Unicem cement showed the highest microhardness values and Calibra the lowest, regardless of the shade selected. All resin luting materials tested exhibited a significantly higher microhardness in the cervical third. Conclusions: Microhardness of resin luting agents tested inside the canal is dependent on material brand and resin cement shade seems to be a less relevant factor. Microhardness decreased along the root canal, regardless of the shade selecte

High-energy ball milling and synthesi temperature study to improve superconducting properties of MgB2 ex-situ tapes and wires

MgB2 monofilamentary nickel-sheated tapes and wires were fabricated by means of the ex-situ powder-in-tube method using either high-energy ball milled and low temperature synthesized powders. All sample were sintered at 920 C in Ar flow. The milling time and the revolution speed were tuned in order to maximize the critical current density in field (Jc): the maximum Jc value of 6 x 10e4 A/cm2 at 5 K and 4 T was obtained corresponding to the tape prepared with powders milled for 144h at 180rpm. Vorious synthesis temperature were also investigated (730-900 C) finding a best Jc value for the wire prepared with powders synthesized at 745 C. We speculate that this optimal temperature is due to the fluidifying effect of unreacted magnesium content before the sintering process which could better connect the grains

Influence of the menstrual cycle on the pressure pain threshold (PPT) of masticatory muscles in women with myofascial pain (RDC/TMD)

O objetivo deste trabalho foi analisar a influência do ciclo menstrual nas alterações de limiar de dor à pressão (LDP) na musculatura mastigatória de mulheres com sinais e sintomas de Disfunção Temporomandibular (DTM). Inicialmente 47 voluntárias entre 18 e 40 anos participaram do estudo, das quais 36 foram incluídas no experimento: 15 com sinais e sintomas de DTM (7 sob terapia com contraceptivos orais (CO) e 8 sem CO) e 21 saudáveis, sem sinais e/ou sintomas de DTM (8 com CO e 13 sem CO). Os LDPs dos músculos masseter e temporais (anterior, médio e posterior), e do tendão de Aquiles foram medidos bilateralmente, por meio de um algômetro, durante 2 ciclos menstruais consecutivos, nas 4 diferentes fases: menstrual (dias 1-3), folicular (dias 5-9), periovulatória (dias 12-16) e lútea (dias 19-23). Em cada fase do ciclo, as voluntárias relataram sua dor em uma Escala de Análise Visual (EVA). Os resultados foram submetidos à análise de variância a 3 critérios para mensurações repetidas, a um nível de significância de 5%.Foram encontrados LDPs significativamente menores nos músculos temporal e masseter e no tendão de Aquiles das mulheres com DTM quando comparado às mulheres assintomáticas, independentemente da fase do ciclo e do uso de contraceptivos (p < 0,05). De uma maneira geral, os LDPs foram maiores em mulheres em terapia com contraceptivos orais, quando comparado às mulheres sem terapia. Parece não existir influência das diferentes fases do ciclo menstrual no LDP, independentemente da presença ou não de DTM.The aim of this study was to investigate the influence of the menstrual cycle on the Pain Pressure Threshold (PPT) figures of the masticatory muscles in women with signs and symptoms of Temporomandibular Disorders (TMD). Forty-seven volunteers (ages between 18-40 years-old) were initially recruited for this purpose. According to the criteria adopted, 36 were included. The experimental group was composed of 15 women with myofascial pain (RDC/TMD) (7 under oral contraceptive medication), while 21 women with no TMD signs or symptoms (8 under oral contraceptive medication) composed the control group. The PPT values of masseter and temporalis (anterior, middle, and posterior regions) muscles, as well as the Achilles? tendon were bilaterally screened during two consecutive menstrual cycles, in the following phases: menstrual (day 1-3), follicular (day 5-9), periovulatory (day 12-16) and luteal (day 19-23). A visual analog scale (VAS) was used to address subjective pain in each menstrual phase. Data were submitted to 3-way ANOVA for repeated measurements, with a 5% significant level. The PPT values were significantly lower in the temporalis, masseter, and the Achilles? tendon of TMD patients when compared with the asymptomatic controls, regardless of the menstrual cycle phase or the use of oral contraceptives (p<.05). Overall, the PPT values were higher for patients under oral contraceptive therapy, while VAS was, in general higher at the menstrual phase (p<.05). It appears that the different phases of menstrual cycle have no influence on the PPT values, regardless of the presence of a previous condition, as myofascial pain

Influence of the menstrual cycle on the pressure pain threshold (PPT) of masticatory muscles in women with myofascial pain (RDC/TMD)

O objetivo deste trabalho foi analisar a influência do ciclo menstrual nas alterações de limiar de dor à pressão (LDP) na musculatura mastigatória de mulheres com sinais e sintomas de Disfunção Temporomandibular (DTM). Inicialmente 47 voluntárias entre 18 e 40 anos participaram do estudo, das quais 36 foram incluídas no experimento: 15 com sinais e sintomas de DTM (7 sob terapia com contraceptivos orais (CO) e 8 sem CO) e 21 saudáveis, sem sinais e/ou sintomas de DTM (8 com CO e 13 sem CO). Os LDPs dos músculos masseter e temporais (anterior, médio e posterior), e do tendão de Aquiles foram medidos bilateralmente, por meio de um algômetro, durante 2 ciclos menstruais consecutivos, nas 4 diferentes fases: menstrual (dias 1-3), folicular (dias 5-9), periovulatória (dias 12-16) e lútea (dias 19-23). Em cada fase do ciclo, as voluntárias relataram sua dor em uma Escala de Análise Visual (EVA). Os resultados foram submetidos à análise de variância a 3 critérios para mensurações repetidas, a um nível de significância de 5%.Foram encontrados LDPs significativamente menores nos músculos temporal e masseter e no tendão de Aquiles das mulheres com DTM quando comparado às mulheres assintomáticas, independentemente da fase do ciclo e do uso de contraceptivos (p < 0,05). De uma maneira geral, os LDPs foram maiores em mulheres em terapia com contraceptivos orais, quando comparado às mulheres sem terapia. Parece não existir influência das diferentes fases do ciclo menstrual no LDP, independentemente da presença ou não de DTM.The aim of this study was to investigate the influence of the menstrual cycle on the Pain Pressure Threshold (PPT) figures of the masticatory muscles in women with signs and symptoms of Temporomandibular Disorders (TMD). Forty-seven volunteers (ages between 18-40 years-old) were initially recruited for this purpose. According to the criteria adopted, 36 were included. The experimental group was composed of 15 women with myofascial pain (RDC/TMD) (7 under oral contraceptive medication), while 21 women with no TMD signs or symptoms (8 under oral contraceptive medication) composed the control group. The PPT values of masseter and temporalis (anterior, middle, and posterior regions) muscles, as well as the Achilles? tendon were bilaterally screened during two consecutive menstrual cycles, in the following phases: menstrual (day 1-3), follicular (day 5-9), periovulatory (day 12-16) and luteal (day 19-23). A visual analog scale (VAS) was used to address subjective pain in each menstrual phase. Data were submitted to 3-way ANOVA for repeated measurements, with a 5% significant level. The PPT values were significantly lower in the temporalis, masseter, and the Achilles? tendon of TMD patients when compared with the asymptomatic controls, regardless of the menstrual cycle phase or the use of oral contraceptives (p<.05). Overall, the PPT values were higher for patients under oral contraceptive therapy, while VAS was, in general higher at the menstrual phase (p<.05). It appears that the different phases of menstrual cycle have no influence on the PPT values, regardless of the presence of a previous condition, as myofascial pain