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101.
Jorge Feijoo Xosé Ramón Nóvoa Teresa Rivas María Jesús Mosquera Javier Taboada Cristina Montojo Fernando Carrera 《Journal of Cultural Heritage》2013,14(5):365-376
We describe the results of electromigration desalination of two soluble salt-contaminated Galician granites. The efficacy of electromigration, which had not been previously applied to granite, was assessed for two types of granite contaminated with a 20% NaCl solution and seawater. Desalination effectiveness was evaluated as follows: (1) analysis of anode and cathode ion content during testing; (2) analysis of ions at different distances from the electrodes after testing; (3) pH assessment of the stone surfaces; and (4) evaluation of colour changes. Results were very satisfactory; by the end of testing, chloride was reduced by almost 100% in both the NaCl and seawater contaminated samples. Sulfate reduction was also significant, despite this ion's lower mobility. The granite pH values remained close to neutral and colour changes were minimal. The difference in effectiveness of the process for the two types of stone was associated with their dissimilar pore structure. 相似文献
102.
García-Fernández Beatriz Sobrino-Costoso Carlos-Emeterio Ruiz-Gallardo José-Reyes 《Research in Science Education》2022,52(4):1109-1129
Research in Science Education - The research compares teachers’ and their pupils’ performance on plant nutrition. The misconceptions of 89 primary school children from one state school... 相似文献
103.
Science & Education - Science and mathematics are universal endeavors. However, the historical perspective of science and mathematics has been westernized across the curriculum in the USA.... 相似文献
104.
Marianne Skopnik-Chicago Katherine Poblete-Cordero Natali Zamora Roberto Bastías Pablo A. Lizana 《Anatomical sciences education》2021,14(6):836-846
One of the most widely used solutions to fix and preserve organic tissues is formaldehyde, despite reservations regarding its toxicity and the fact that formaldehyde-embalmed bodies lose their original characteristics. Anatomy laboratories have been replacing formaldehyde with solutions that retain the characteristics of fresh tissue. For this purpose, alternative solutions with a very low concentration of formaldehyde or without any formaldehyde have been analyzed. The objective of this study was to compare biometry, coloration, haptic properties, and bacterial load on animal specimens (pig kidneys) embalmed with formaldehyde, and with Chilean Conservative Fixative Solution with and without formaldehyde (formaldehyde chCFS and formaldehyde-free chCFS). Also, the perception of health and biological science students toward specimens treated with different solutions was assessed. The results indicated that there were no significant differences in specimens’ retraction, or bacterial load. Students showed a preference for organs embalmed in formaldehyde chCFS and formaldehyde-free chCFS; indicating that with these treatments they could better visualize structures and that the prosections had greater flexibility and the colors were more similar to those of fresh tissue. Additionally, students recommended the material embalmed in formaldehyde chCFS and formaldehyde-free chCFS for anatomy learning. In contrast, students indicated that formaldehyde-fixation negatively affected their practical experience. In conclusion, embalming with formaldehyde chCFS or formaldehyde-free chCFS provides an advantageous practical experience over the use of formaldehyde and may be an alternative to replace the use of formaldehyde in anatomy laboratories. 相似文献
105.
Carla Márquez Rodolfo Solís-Vivanco Astrid Schilmann Humberto Nicolini 《Parenting, science and practice》2021,21(1):47-54
SYNOPSIS Objective . To explore whether maternal sensitivity is associated with Autism Spectrum Disorder (ASD) severity in children with and without ASD. Design . The samples consisted of 25 Mexican dyads of children with ASD (aged 3.1-6.9 years) and their mothers (aged 20-47 years) and 24 Mexican dyads of children without ASD (aged 3.4-6.7 years) and their mothers (aged 24-45 years). Maternal sensitivity and ASD severity symptoms were scored from 2-h videos of mother-child daily interactions. Results . A between-group comparison showed a trend toward less severe ASD in children with highly sensitive mothers, specifically in the Nonverbal Communication subdomain. Conclusions . Greater maternal sensitivity is associated with improved social ability in children with ASD. 相似文献
106.
ResumenEl déficit atencional en niños hiperactivos ha sido investigado a partir de las teorías tradicionales de la atención. Este trabajo incorpora las recientes teorías de limitaciones en la capacidad de procesamiento mediante un paradigma de doble tarea (visual y auditiva). Se manipula el nivel de dificultad de la tarea secundaria y se comprueba su efecto en niños hiperactivos (n-=28) y normales (n=28) de 2.°-3.° y 4.°-6.° cursos de EGB. Los resultados permiten sostener que al aumentar la dificultad de la tarea secundaria, los hiperactivos de 4.°-6.° tienen peor ejecución que los controles de los mismos cursos y edad, mientras que en 2.°-3.° ocurre lo contrario. Los hiperactivos muestran una mayor inestabilidad y labilidad en la asignación de recursos y/o en los límites de capacidad de procesamiento. 相似文献
107.
Kandia Lewis Lia E. Sandilos Carol Scheffner Hammer Brook E. Sawyer Lucía I. Méndez 《Early education and development》2016,27(4):478-494
Research Findings: This study explored the relations between Spanish–English dual language learner (DLL) children’s home language and literacy experiences and their expressive vocabulary and oral comprehension abilities in Spanish and in English. Data from Spanish–English mothers of 93 preschool-age Head Start children who resided in central Pennsylvania were analyzed. Children completed the Picture Vocabulary and Oral Comprehension subtests of the Batería III Woodcock–Muñoz and the Woodcock–Johnson III Tests of Achievement. Results revealed that the language spoken by mothers and children and the frequency of mother–child reading at home influenced children’s Spanish language abilities. In addition, the frequency with which children told a story was positively related to children’s performance on English oral language measures. Practice or Policy: The findings suggest that language and literacy experiences at home have a differential impact on DLLs’ language abilities in their 2 languages. Specific components of the home environment that benefit and support DLL children’s language abilities are discussed. 相似文献
108.
Juan García-López Sergio Díez-Leal Ana Ogueta-Alday Josu Larrazabal José A. Rodríguez-Marroyo 《Journal of sports sciences》2016,34(17):1619-1626
The purpose of this study was to compare the pedalling technique in road cyclists of different competitive levels. Eleven professional, thirteen elite and fourteen club cyclists were assessed at the beginning of their competition season. Cyclists’ anthropometric characteristics and bike measurements were recorded. Three sets of pedalling (200, 250 and 300 W) on a cycle ergometer that simulated their habitual cycling posture were performed at a constant cadence (~90 rpm), while kinetic and kinematic variables were registered. The results showed no differences on the main anthropometric variables and bike measurements. Professional cyclists obtained higher positive impulse proportion (1.5–3.3% and P < 0.05), mainly due to a lower resistive torque during the upstroke (15.4–28.7% and P < 0.05). They also showed a higher ankle range of movement (ROM, 1.1–4.0° and P < 0.05). Significant correlations (P < 0.05) were found between the cyclists’ body mass and the kinetic variables of pedalling: positive impulse proportion (r = ?0.59 to ?0.61), minimum (r = ?0.59 to ?0.63) and maximum torques (r = 0.35–0.47). In conclusion, professional cyclists had better pedalling technique than elite and club cyclists, because they opted for enhancing pulling force at the recovery phase to sustain the same power output. This technique depended on cycling experience and level of expertise. 相似文献
109.
Alberto Fílter Jesús Olivares Alfredo Santalla Fabio Y. Nakamura Irineu Loturco Bernardo Requena 《Journal of sports sciences》2020,38(11-12):1320-1325
ABSTRACT The speed performance is involved not only in linear sprints, but also in a wide spectrum of multi-directional movements, such as curve sprinting. Curved sprint can be defined as sprint with gradual and continuous change of direction (COD). Although ~85% of the actions performed at maximum velocity in a professional soccer league are curvilinear sprints, there is not any specific test to assess this ability. This study aimed to analyse the reliability of a new curve sprint test, and compare its results with those obtained by soccer players in linear sprint. Forty experienced soccer players performed 3 attempts of curve sprint (using the penalty arc) to right and left side (17 m), and 3 linear sprints (17 m) in two different days. The ICCs (inter-session reliability) were 0.93 for sprint curve right side (CSRS) and 0.89 for sprint curve left side (CSLS), considered “acceptable”. The CVs (intra-session reliability) were 0.87% in CSRS and 1.15% in CSLS. The coefficient of determination (R2) between linear and curve sprinting was ~35%. The association between curve sides was “very large” (r = 0.878; p < 0.01). In summary, we showed that “curve sprint test” is highly reliable, and that curvilinear and linear sprints are different and independent actions. 相似文献
110.