Louis C. Muller^1*, Sanette Marx¹, Hermanus C.M. Vosloo²

Journal of Renewable Materials, Vol.5, No.1, pp. 67-80, 2017, DOI:10.7569/JRM.2016.634130

Abstract This work reports a study of polyol synthesis through liquefaction of technical lignins in crude glycerol by means of 1H and 31P NMR spectroscopy. The polyols are intended for preparation of polyurethane foam; thus, it is important to know how different lignin types as well as crude glycerol influence and contribute to the final polyol hydroxyl contents. Polyols prepared from organosolv lignin, kraft lignin and lignosulphonate had hydroxyl numbers suitable for rigid foam of 435, 515 and 529 mgKOH/g, respectively. The polyols differed in composition with glycerol, showing significant variation. During liquefaction the glycerol content More >

A. Paberza^*, L. Stiebra, U. Cabulis

Journal of Renewable Materials, Vol.3, No.1, pp. 19-27, 2015, DOI:10.7569/JRM.2014.634138

Abstract Rigid polyurethane foams were obtained from pulp production byproducts. Three different polyols were used—tall oil polyol, lignopolyol and commercially available polyol for comparison. The obtained rigid polyurethane foams underwent photodegradation at 60°C temperature and at 0.89 W/m² intensity of UV light radiation up to 1000 h. Changes in chemical structure were observed by Fourier Transform Infrared Spectroscopy and Scanning Electron Microscopy was used to study changes in cell morphology. Spectrophotometery was used to determine yellowing of the foams. Results showed that the thickness of degraded layer for rigid polyurethane foams obtained from pulp production byproducts was More >

Antonio J. F. Carvalho

Journal of Renewable Materials, Vol.2, No.2, pp. 118-122, 2014, DOI:10.7569/JRM.2014.634108

Abstract Two nanocelluloses from eucalyptus, namely microfi brillated cellulose (MFC) and cellulose nanocrystals (CNC), were prepared and compared by transmission electron microscopy (TEM). The MFC fi bers are 20–30 nm wide and are composed of very homogeneous bundles of aligned regular elementary fi brils of 3–5 nm diameter. They show long straight portions and short fl exible zones, attributed to crystalline and amorphous zones, respectively. The needle-shaped CNC was approximately 200 nm long and 10 nm wide in the wider portion. A model for the MFC structure, whose fl exible zones are formed by alignment of More >

Antti Ojala^1,*, Lisa Wikström¹, Kalle Nättinen², Jani Lehmonen³, Karita Kinnunen-Raudaskoski⁴

Journal of Renewable Materials, Vol.2, No.4, pp. 278-284, 2014, DOI:10.7569/JRM.2014.634126

Abstract This article presents a new method of producing thermomoldable nonwoven materials based on kraft lignin (KL) and softwood kraft pulp (KP). A mixture of starch acetate (SA) and triethyl citrate (TEC) was used as a water insoluble plasticizer for KL. The thermoplastic lignin (TPL) material with the optimized ratio of KL, SA and TEC was prepared in a twin-screw extruder. The TPL compound was ground and mixed with KP fi bers to produce thermoformable sheets using foam-laid technology. The formed webs were compression molded (CM) into plates and mechanically tested. The foam-laid composites had tensile More >

F. S. Tabatabaei^∗, M. Jazayeri^†, P. Ghahari^‡, N. Haghighipour^§

Molecular & Cellular Biomechanics, Vol.11, No.3, pp. 209-220, 2014, DOI:10.3970/mcb.2014.011.209

Abstract During orthodontic treatments, applied mechanical forces create strain and result in tooth movement through the alveolar bone. This response to mechanical strain is a fundamental biological reaction. The present study evaluated the effect of equiaxial strain within the range of orthodontic forces on the osteogenic differentiation of human dental pulp stem cells (hDPSCs). Following isolation and culture of hDPSCs, 3rd passage cells were transferred on a silicone membrane covered with collagen. Cell adhesion to the membrane was evaluated under scanning electron microscope (SEM). Cells were divided into three groups: the first group was placed in… More >

ALICIA KOHLI¹ , STELLA M. PEZZOTTO² , GRACIELA GARCIA³ , LEONOR C. POLETTO².

BIOCELL, Vol.35, No.2, pp. 51-58, 2011, DOI:10.32604/biocell.2011.35.051

Abstract The embryological, structural and functional unit of the dentine-pulp complex shares the odontoblast, located in the border of the dentine pulp, with basal nuclei and organelles. The odontoblast process emerges from its apical pole. It is formed by microtubules, microfilaments and vesicles covered by membranes penetrating the dentinal tubules, isolated from the inter-tubular matrix, along the extent of the dentine. The objective of this study was to evaluate the efficacy of three staining techniques: hematoxylin-eosin, periodic acid-Schiff and Schmorl, by staining the process, from beginning to end, and compare the results with the erosion More >

P. E. Murray¹, F. Garcia-Godoy¹

Molecular & Cellular Biomechanics, Vol.3, No.4, pp. 139-140, 2006, DOI:10.32604/mcb.2006.003.139

Abstract This article has no abstract. More >