Anatomical characterization and technological properties of Pterogyne nitens wood, a very interesting species of the Brazilian Caatinga biome

Pterogyne nitens is commonly known in northeastern Brazil as a lesser-known fast-growing species in the Caatinga biome, which is a difficult place for tree development due to the low natural fertility soils and low availability of water. Due to the importance of expanding information about the anatomical wood properties of Caatinga native species, the aim of this work was to characterize the anatomical elements, to macroscopically describe the wood and make inferences about its possible end-uses. Maceration was performed which enabled measuring fiber dimensions, pore frequency and the following technological indexes: cell wall fraction, slenderness ratio, Runkel index and flexibility coefficient. Histological sections enabled describing the arrangements of the cellular elements in different observation sections and to determine the pore diameter. P. nitens wood has anatomical arrangements characterized by confluent axial parenchyma, being diffuse-porous with the presence of tylosis and heterogeneous/stratified rays (biseriate). The fibers were classified as very short (length 0.81 mm), not flexible and Runkel index 0.82. The pores were few in number with a frequency of 32.9 pores/mm2, distributed in a diffuse format and many were obstructed by tylosis. Based on the anatomical results and considering other technological studies, P. nitens wood is most suitable for charcoal production.

Cellulose Microfibers from Salacca Midrib Fiber Isolated by the Mechanical Treatment

Salacca midrib fibers are abundant natural waste in Turi, Sleman Regency, Daerah Istimewa Yogyakarta. Cellulose Microfibers from the salacca midrib fiber has been isolated by mechanical treatment and successfully has good physical characteristics. Cellulose fibers with micro sizes can strengthen the bond effect between the matrix and the fiber due to the vast contact area. The method for isolated cellulose microfibers by mechanical treatment for speed rotation of 5000, 10000 and 15000 rpm. Mechanical stirrer treatment aims to fibrillation and reduces fiber dimensions because of their high rotation. The characterization by XRD, FTIR, and SEM. The XRD results showed that the mechanical stirrer treatment did not damage the crystallinity index of cellulose microfibers. The crystallinity index of the raw material is 64.3%, increased to 79.1% for the microfiber cellulose crystallinity index. Identification of functional groups using FTIR did not show changes in cellulose compounds resulting from mechanical treatment. Morphological observation of fibers by SEM shows that the diameter cellulose microfibers size obtained from salacca midrib fiber ranges 5-10 µm with 100-300 µm in length. Cellulose microfibers have potential materials as reinforcement in the micro composite and extraction into nanocellulose materials.

Trends in the Design of Intensity-Based Optical Fiber Biosensors (2010–2020)

There exists an increasing interest in monitoring low concentrations of biochemical species, as they allow the early-stage detection of illnesses or the monitoring of the environment quality. Thus, both companies and research groups are focused on the development of accurate, fast and highly sensitive biosensors. Optical fiber sensors have been widely employed for these purposes because they provide several advantages for their use in point-of-care and real-time applications. In particular, this review is focused on optical fiber biosensors based on luminescence and absorption. Apart from the key parameters that determine the performance of a sensor (limit of detection, sensibility, cross-sensibility, etc.), other features are analyzed, such as the optical fiber dimensions, the sensing set ups and the fiber functionalization. The aim of this review is to have a comprehensive insight of the different aspects that must be taken into account when working with this kind of sensors.

Pulp and Papermaking Characteristics of South Sudanese Cordia Africana (Gambil) Wood

Objective The wood of an important indigenous Sudanese hardwood species, Cordia africana lam, was examined to determine its suitability for pulp and papermaking. Basic density, bark-to-wood ratio, fiber dimensions and chemical composition were studied. Results Pulps were evaluated and papermaking characteristics were tested. C. africana wood showed medium basic density (410 kg m-1). The average bark-to wood ratio by mass (6.82%) and volume (11.67%) were in the normal average for pulpwood and could be used for production of high grade pulp. The fibers of C. africana were long with an average fiber length of 1.13 mm, average fiber diameter was 30 µm with an average lumen diameter 20 µm and cell wall thickness of 5 µm. the wood showed high ash content (2.7%), high pentosans (25%), relatively medium lignin content (23.9%).C. africana pulped with 12-15% alkali charge as Na2O for two hours at 170 0C gave good Kappa numbers with normal and relatively high yield with very low rejects. The addition of 0.13% anthraquinone (AQ) in cooking liquor reduced the active alkali consumption by 2-2.3%, increased the pulp yield and reduced bleachable Kappa numbers. The pulp produced suitable for wrapping paper and paperboard.

Development of PLA Fibers as an Antimicrobial Agent with Enhanced Infection Resistance using Electrospinning/Plasma Technology

Humans are vulnerable and easily prone to all kind of injuries, diseases, and traumas that can be damaging to their tissues (including its building unit, cells), bones, or even organs. Therefore, they would need assistance in healing or re-growing once again. Medical scaffolds have emerged over the past decades as one of the most important concepts in the tissue-engineering field as they enable and aide the re-growth of tissues and their successors. An optimal medical scaffold should be addressing the following factors: biocompatibility, biodegradability, mechanical properties, scaffold architecture/porosity, precise three-dimensional shape and manufacturing technology. There are several materials utilized in the fabrication of medical scaffolds, but one of the most extensively studied polymers is polylactic acid (PLA). PLA is biodegradable thermoplastic aliphatic polyester that is derived from naturally produced lactic acid. PLA is characterized with its excellent mechanical properties, biodegradability, promising eco-friendly, and excellent biocompatibility. PLA can be fabricated into nanofibers for medical scaffolds used through many techniques; electrospinning is one of the widely used methods for such fabrication. Electrospinning is a favorable technique because in the preparation of scaffolds, some parameters such as fiber dimensions, morphology, and porosity are easily controlled. A problem that is associated with medical scaffolds, such as inflammation and infection, was reported in many cases resulting in a degradation of tissues. Therefore, a surface modification was thought of as a needed solution which mostly focuses on an incorporation of extra functionalities responsible for the surface free energy increase (wettability). Therefore, plasma technique was a favorable solution for the surface treatment and modification. Plasma treatment enables the formation of free radicals. These radicals can be easily utilized for grafting process. Subsequently, ascorbic acid (ASA) could be incorporated as anti-inflammatory and anti-infection agent on the plasma pretreated surface of scaffolds.

“SEW” What Do We Know and Where Do We Go? A Review of Socioemotional Wealth and a Way Forward

This analysis provides a review of family business literature concerning the application of socioemotional wealth (SEW) and its extension through the FIBER framework. Specifically, we answer Brigham and Payne’s call by assessing the multidimensionality of the SEW construct, the interrelatedness of the dimensions, and its specificity to family firms. We contribute to the literature by conducting a systematic review of the SEW literature and examining the applications of the FIBER dimensions, noting the evolution of specific research themes. Last, using necessary condition analysis, we provide four conceptual inferences regarding the assumptions of SEW to provide a way forward.

Geographic Variations of the Wood Density and Fiber Dimensions of the Persian Oak Wood

Persian oak (Quercus brantii Lindl.) is a valuable native species in Iranian forests with very limited availability of data on its wood properties. The objective of the current study was to determine the influence of altitude and slope on physical properties and fiber dimensions of Persian oak wood. In addition, the relationship among wood properties, site conditions (temperature and rainfall) and growth traits of trees (tree height, DBH, basal area, age, crown diameter, crown basal area, volume and annual diameter increment) were studied by principal component analysis (PCA). Three altitude levels (1730, 1980 and 2250 m) and three slope classes (<30%, 30–45% and >45%) were considered in the current study. It was determined that trees growing in the intermediate altitude (1980 m) showed the highest oven-dry density values, and those in the lowest altitude (1730 m) revealed the lowest ones. The results also indicate significant statistical differences between altitude levels and slope classes on the fiber length, fiber diameter and volumetric swelling at the 99% confidence interval while no significant differences were found between average values of oven-dry density among different altitudes and slopes. PCA analysis indicated that altitude and temperature are the most important factors affecting the wood properties. Knowledge of the relationship between wood properties and environmental factors are essential in terms of both forestry management and wood applications.