Preparation of Modified Kaolin Filler with Cesium and Its Application in Security Paper

In this study, cesium was added intentionally during paper manufacture for protecting the papers against forgery and counterfeiting by sorbing cesium ions (Cs+) on kaolin, used as special filler in papermaking. The sorption of cesium from aqueous solution by kaolin was studied as a function of pH, shaking time, cesium initial concentration, and mass of kaolin using batch technique. The results showed that a solution containing 10 mg/L Cs+ and 250 mg of kaolin at pH 6 can be used to modify the kaolin. Paper handsheets were prepared containing various percentages of the modified kaolin. The mechanical and optical properties of paper handsheets were studied. The prepared paper handsheets were irradiated by gamma irradiation using different doses. Fourier transform infrared (FTIR) spectroscopy was used to study the effect of kaolin modification by cesium and gamma irradiation on paper handsheets properties. The results indicated that modified kaolin enhanced the mechanical and optical properties of paper handsheets. Electron spin resonance (ESR) spectroscopy and laser-induced breakdown spectroscopy (LIBS) were also used. They provided rapid, sensitive and nondestructive techniques in differentiating between different questioned documents. This study presents a new concept in manufacturing security papers and anticounterfeiting applications

Evaluation of palm fiber components an alternative biomass wastes for medium density fiberboard manufacturing

This work deals with assessing the date palm component wastes as alternative lignocellulosic material for production of Medium density fiberboards, in order to establish economic and balance between production/consumer ratio at different provinces rather than Upper Egypt. Palm leafs and palm frond was used as Medium density fiberboards precursors. Different urea formaldehyde levels (10-14%/fiber) and pressing pressure (25-35 bar) were applied in this evaluation. The acceptable interaction of palm fibers component with urea formaldehyde was optimized by characterizing its differential scanning calorimetry and thermogravimetric analysis, in comparison with commercial used sugarcane bagasse fibers. The promising Medium density fiberboards Panel is obtained from palm frond fibers and its mechanical and water resistance properties fulfill the ANSI standard for high grade Medium density fiberboards wood products, especially on applying urea formaldehyde level 12-14%, and pressing pressure, 35 bar. It is interesting to note that, applying higher pressing pressure together with 12% urea formaldehyde level provided palm frond-based Medium density fiberboards with static bending properties, higher than commercial bagasse-based Medium density fiberboards. The insignificant effect of pressing pressure was noticed on water swelling property and free-HCHO of Medium density fiberboards panels.  Where, both type of fibers have the same water swelling property (reached ~ 10%), and free-HCHO (~ 27 mg/100g board)

PRODUCTION AND CHARACTERIZATION OF ECONOMICAL BACTERIAL CELLULOSE

The present study investigates the economical production of bacterial cellulose (BC) by Gluconacetobacter subsp. Xylinus (ATCC 10245) in 250 ml Erlenmeyer flasks cultivated under static conditions. The fermentation media used contained food industrial by-product liquors, such as black strap molasses solution and corn steep liquor (CSL), which represents some of the most economical carbon and nitrogen sources. However, because of the presence of undesirable components in molasses (such as coloring substances, heavy metals, and other compounds) that may act as inhibitors, and in order to eliminate them, crude molasses has been treated with an acid, as an attempt to increase BC productivity. The amount of BC produced using these carbon and nitrogen sources was determined and compared to that produced using previously reported fermentation media. The characterizations of the bacterial cellulose (BC) pellicles obtained using either conventional or by-product media were studied by thermal and spectral techniques and compared to those of plant-derived cellulose such as cotton linter, viscose pulp, and microcrystalline cellulose

Bio-chemical properties of sandy calcareous soil treated with rice straw-based hydrogels

AbstractCompletely randomized drip irrigated field experiments, with three replications for each treatment, were conducted at El-Saff-Giza Governorate, Egypt to evaluate the beneficial effects of applying the rice straw (RS)-based hydrogels as soil conditioners for sandy calcareous soil. In this respect three successive growing seasons (summer season 2010 using tomatoes vs. custle rock, winter season 2010–2011 using wheat vs. Seds 1 intercropped with onion vs. Giza 20, and summer season 2011 using caw pea vs. Bafb as indicator crops) were carried out. Two rice straw-based hydrogels (with two rates; 2 and 4gkg−1 soil) were examined. After the third growing season some biochemical properties of the soil were determined.The results obtained show that, application of the investigated hydrogels positively affects bio-chemical properties of the soil. These effects are assembled in the following: (a) slightly decreasing soil pH, (b) increasing cation exchange capacity (CEC) of the soil indicating improvement in activating chemical reactions in the soil, (c) increasing organic matter (OM), organic carbon, total nitrogen percent in the soil. Because the increase in organic nitrogen surpassed that in organic carbon, a narrower CN ratio of treated soils was obtained. This indicated the mineralization of nitrogen compounds and hence the possibility to save and provide available forms of N to growing plants, (d) increasing available N, P and K in treated soil, and (e) improving biological activity of the soil expressed as total count of bacteria and counts of Azotobacter sp., phosphate dissolving bacteria (PDB), fungi and actinomycetes/g soil as well as the activity of both dehydrogenase and phosphatase