CHARACTERIZATION OF ANATOMICAL, MORPHOLOGICAL, PHYSICAL AND CHEMICAL PROPERTIES OF KONAR (ZIZIPHUS SPINA-CHRISTI) WOOD

The goal of this research is to investigate some morphological (fibre length, fibre diameter, cell wall thickness, Runkel coefficient, flexibility coefficient, slenderness coefficient, rigidity coefficient, Luce's coefficient, solid coefficient), physical (dry wood density, volumetric shrinkage) and chemical (cellulose, hemicellulose, lignin, ash and acetone soluble extractives contents) composition of Konar (Ziziphus spina-christi) wood grown in Hormozgan province, Iran. For this purpose, three normal trees were selected randomly and a disk was cut from each one at breast height. Anatomical inspection revealed that the species was diffuse porous, with distinctive growth rings, simple preformation plate, with polygonal openings, and banded or diffuse-in aggregates parenchyma. The average values of wood dry density, fiber length, fiber diameter, cell wall thickness, Runkel coefficient, flexibility coefficient, felting coefficient, Luce’s coefficient, solid coefficient, rigidity coefficient were 0.926, 52.1, 77.85, 0.57, 163 ×103 μ3 and 0.48. Cellulose, hemicellulose, lignin, acetone soluble, extractives, ashcontents were43.34, 19.98, 33.9, 6.42 and 2.78%, resp.

A comparative fiber morphological analysis of major agricultural residues (used or investigated) as feedstock in the pulp and paper industry

The suitabilities of major agricultural residues were assessed as papermaking feedstocks. All the examined agricultural residues were assumed as potential candidates for substituting hardwood fibers in mixed pulp blends from a fiber morphological perspective. Wheat, barley, rice, rapeseed, maize, sunflower, sugarcane bagasse, coconut husk, and two genotypes of miscanthus grass underwent identical maceration. The fiber length, fiber width, cell wall thickness, and lumen diameter were measured to calculate the slenderness ratio, flexibility coefficient, and Runkel ratio. The average fiber length ranged from 0.50 mm ± 0.32 mm (MG-S-02-V) to 1.15 mm mm ± 0.58 mm (sugarcane bagasse). The fiber width ranged from 10.77 μm ± 3.28 μm (rice straw) to 22.99 mm ± 5.20 mm (sunflower stalk). The lumen diameter ranged from 4.52 μm ± 2.52 μm (rice straw) to 13.23 μm ± 4.87 μm (sunflower stalk). The cell wall thickness ranged from 3.02 μm ± 0.95 μm (rice straw) to 4.80 μm ± 1.48 μm (sunflower stalk). The slenderness ratio, flexibility coefficient, and Runkel ratio values ranged between 28.08 to 58.11, 37.97 to 60.8, and 0.62 to 1.68, respectively. Wheat, maize, rapeseed, sugarcane bagasse, and coconut husk were found to be appropriate residue sources for papermaking feedstocks.

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.

Vibration Propagation Analysis of Periodic Pipeline With Crack Defects

In this paper, the vibration propagation characteristic is investigated for periodic composite pipeline with crack damage. A novel modified transfer matrix method (TMM) is developed to investigate transverse Band Gap structures (BGs) considering fluid structure interaction, and validated by frequency response function (FRF) for finite period. Field transfer matrix is developed for straight pipeline conveying fluid, and point transfer matrix is derived for circumferential cracks damage based on spring hinge model, which could estimate the equivalent rotational stiffness by local flexibility coefficient method. It’s demonstrated that the existence of small crack damage has negligible effect on BGs, while severe crack damage has significant influence on vibration propagation even it only exists in a single cell. Meanwhile, the difference of FRF between cracked and perfect pipeline provides new idea in diagnosing the crack status. The influence of crack damage on BGs is mainly attributed to the equivalent rotational stiffness. Location of crack damage could affect the stiffness ratio of composite pipeline, and result in the change of original BGs. This study enriches the theoretical TMM for pipeline systems vibration with crack damage, and provides some reference for the stability design of periodic pipeline structures.

On non-axisymmetric buckling modes of inhomogeneous circular plates

Unsymmetrical buckling of nonuniform circular plates with elastically restrained edge and subjected to normal pressure is studied in this paper. The asymmetric part of the solution is sought in terms of multiples of the harmonics of the angular coordinate. A numerical method is employed to obtain the lowest load value at which waves in the circumferential direction can appear. The effect of material heterogeneity and boundary on the buckling load is examined. For a plate with elastically restrained edge, the buckling pressure and mode number increase with a rise of spring stiffness. Increasing of the elasticity modulus to the plate edge leads to increasing of the buckling pressure, but the mode number does not change. If the translational flexibility coefficient is small, decreasing of the elasticity modulus to the shell (plate) edge leads to sufficient lowering of the buckling pressure.

Characterization of chia plant (Salvia hispanica) for pulping

In this paper, chia plant was characterized in terms of chemical, morphological, and anatomical properties. Chia plant was characterized with low α-cellulose (30.5%); moderate lignin (23.2%) with syringyl to guaiacyl ratio of 1.41; and shorter fiber length (0.67 mm) with thinner cell wall (1.91 μm) and good flexibility coefficient (71.44). Anatomical features showed that chia plant consists of vessels, fibers, parenchyma cells, and collenchyma cells. Chia plant pulping was evaluated in soda-anthraquinone (soda-AQ) and formic acid/peroxyformic acid (FA/PFA) processes. Chia plant was difficult to delignify in the alkaline process. The FA/PFA process produced higher pulp yield at the same kappa number than the soda-AQ process. Unbleached soda-AQ chia pulp exhibited good proper-ties in terms of tensile, bursting, and tearing strengths, even at the unrefined stage, due to high drainability of the pulps. Alkaline peroxide bleached FA/PFA pulp exhibited better papermaking properties and 2% higher brightness than the D0(EP)D1 bleached soda-AQ pulp.

Model-driven fault diagnosis of slant cracks in aero-hydraulic straight pipes

A model-driven fault diagnosis method for slant cracks in aero-hydraulic straight pipes is presented in this paper. First, fracture mechanics theory and the principle of strain energy release are used to derive an expression for the local flexibility coefficient of straight pipes with slant cracks. The inverse method of total flexibility is used to calculate the stiffness matrix of straight pipe elements with slant cracks. Second, the Euler-Bernoulli beam model theory is used in conjunction with the finite element method to construct a dynamic model of the cracked pipe. Finally, a contour map method is used to diagnose the slant crack fault and quantitatively determine the crack position and depth. Experimental results show that the proposed method can accurately and effectively identify a slant crack fault in aero-hydraulic pipelines.

Anatomical, morphological and chemical characteristics of kaun straw (Seetaria-ltalika)

Anatomical, morphological and chemical characteristics of kaun straw were examined to assess their suitability for paper production and the properties were compared with wheat straw and rice straw. It was found that the fiber length of kaun straw is slightly shorter than that of wheat straw and longer than that of rice straw. It has wider fiber wall thickness than that of wheat straw and rice straw. It had acceptable derived values, especially slenderness ratio, which was lower than that of wheat straw and rice straw, and higher runkel ratio and lower flexibility coefficient. Chemical analysis of kaun straw revealed satisfactory levels of α-cellulose content (35.9 %) and klason lignin content (19.3 %). The ash content in kaun straw (7.32 %) showed lower value than that of wheat straw and rice straw. In optimum cooing conditions, kaun straw produced pulp yield of 30.0 % and 41.7 % with kappa number 15.1 and 22.5 in soda-AQ and formic acid pulping processes, respectively, the values of which were lower than that of wheat straw and rice straw.

Vegetable Prices Possess Seasonal Volatility: A Case Study of Lahore, Punjab, Pakistan

The present research was conducted to determine the seasonal volatility of four important vegetables in Pakistan. The four vegetables included in this study are onion, tomato, potato, and cabbage. The first three of which are necessary kitchen items in the food consumption of the country. The study area is comprised of the Lahore district of the Punjab province which is the most populous city in the province and the major producer of the vegetables in the country. Secondary data of the year 2010 and 2011 about prices and quantity of these four vegetables were collected from the market committee and agriculture marketing information system Lahore. The price flexibility coefficient was estimated along with the seasonal behavior concerning prices for perishable vegetables. The results indicate that the irregular seasonal and cyclical fluctuations observed every year. Price fluctuations for onion, tomato, potato, and cabbage are seasonal. After the harvest, low prices were observed while price were observed high before the start of the season when relative supply shortage occursand vice versa. Hence, the study suggests that prices can be controlled by intervening in the market by increasing supply and production using new technology and high yielding seed varieties.