A Study on Experiences and Understandings of Educational Counseling for Teacher Training Course Students : Toward the Establishment of Educational Counseling Activities in Schools

　本研究の目的は，学校における教育相談活動の定着に向けて，教員養成課程学生を対象に教育相談に関する経験や理解を明らかにすることであった。「教育相談論 A」の受講生を対象に，中学生当時の教育相談活動経験を尋ねた。また，講義前後での教育相談活動に対する理解の変容を計量テキスト分析によって検討した。その結果，多くの学生の教育相談に関する経験は主として学期に１回程度の担任との面談であり，生徒側からは教育相談活動の機能や校内支援体制について具体的に捉えづらい状況にあった。また，教育相談活動について，講義前は，子どもが抱える悩みを個別に解決することが教育相談の役割であると理解していたが，講義後には，子どもや保護者，教師が抱える課題に対して，教育相談コーディネーターが中心となり，チーム支援体制を構築して対応するといった理解へと変容した。最後に，こうした理解の変容を促すために，講義で事例検討を行う意義について議論した

Atomic-scale dents on cellulose nanofibers: the origin of diverse defects in sustainable fibrillar materials

セルロースナノファイバーに生じた原子レベルの欠陥構造を発見 --理想的なバイオポリマー材料の生産にむけて--. 京都大学プレスリリース. 2022-10-07.Atomic-scale dent structures on the surfaces of cellulose nanofibers were detected. These dent parts constituted at least 30–40% of the total length of the dispersed nanofibers, and deep dents induced the kinking and fragmentation of nanofibers

Cross-polarization dynamics and conformational study of variously sized cellulose crystallites using solid-state 13C NMR

Cellulose forms crystalline fibrils, via biosynthesis, that can be just a few nanometers wide. The crystallinity is a structural factor related to material performance. Recently, many routes to isolate these fibrils as nanocellulose have been developed, and there exist various types of nanocellulose with different crystallinities. Quantitative assessment of the crystallinity of nanocellulose is thus essential to advance knowledge in the high performance and functionality of such materials. Solid-state 13C cross-polarization/magic-angle spinning (CP/MAS) nuclear magnetic resonance (NMR) spectroscopy is a strong tool to investigate the structural features and dynamics of solid cellulose. The crystallinity is often evaluated by using the NMR signal ratio of the C4 crystalline and noncrystalline regions as a crystallinity index (CI) value. To calculate the CI value, it is necessary to examine the dependence of the contact time (CT) for CP on the signal intensity and set the optimum CT at a maximum of the signal intensity. However, the dependence has not been investigated for evaluation of the CI value of various cellulose samples with different crystal sizes. Here, we optimized the CT for evaluation of the CI value of cellulose with different crystal sizes. The error in the CI at the optimized CT was ~ 3%. At the optimized CT, the structural change after surface modification by TEMPO-oxidation was also analyzed from the NMR spectra of the C6 region. The relationship between the CI value and the degree of oxidation shows that it is possible to evaluate the degree of oxidation from the NMR spectra irrespective of the crystallinity of cellulose. Furthermore, the C4-based CI value was linearly correlated with the C6-based trans-gauche (tg) ratio, which is approximated by a function, CI = 0.9 tg ratio

Nanocellulose Xerogels With High Porosities and Large Specific Surface Areas

Xerogels are defined as porous structures that are obtained by evaporative drying of wet gels. One challenge is producing xerogels with high porosity and large specific surface areas, which are structurally comparable to supercritical-dried aerogels. Herein, we report on cellulose xerogels with a truly aerogel-like porous structure. These xerogels have a monolithic form with porosities and specific surface areas in the ranges of 71–76% and 340–411 m2/g, respectively. Our strategy is based on combining three concepts: (1) the use of a very fine type of cellulose nanofibers (CNFs) with a width of ~3 nm as the skeletal component of the xerogel; (2) increasing the stiffness of wet CNF gels by reinforcing the inter-CNF interactions to sustain their dry shrinkage; and (3) solvent-exchange of wet gels with low-polarity solvents, such as hexane and pentane, to reduce the capillary force on drying. The synergistic effects of combining these approaches lead to improvements in the porous structure in the CNF xerogels

Surfactant controlled zwitterionic cellulose nanofibril dispersions

Zwitterionic cellulose nanofibrils (ZCNF) with isoelectric point of 3.4 were obtained by grafting glycidyltrimethylammonium chloride onto TEMPO/NaBr/NaOCl-oxidised cellulose nanofibrils. ZCNF aqueous dispersions were characterized via transmission electron microscopy, rheology and small angle neutron scattering, revealing a fibril-bundle structure with pronounced aggregation at pH 7. Surfactants were successfully employed to tune the stability of the ZCNF dispersions. Upon addition of the anionic surfactant, sodium dodecyl sulfate, the ZCNF dispersion shows individualized fibrils due to electrostatic stabilization. On the contrary, upon addition of the cationic species dodecyltrimethylammonium bromide, the dispersion undergoes charge neutralization, leading to more pronounced flocculation