Treesearch

This review summarizes patents related to paper recycling that were issued during the last six months of 2002. Two on-line databases, Claims/U.S. Patents Abstracts and Derwent World Patents Index, were searched for this review. This semiannual feature is intended to inform readers about recent developments in equipment design, chemicals, and process technology for recycling paper, and alternative products derived from postconsumer paper. Only brief summaries of individual inventions are included in this review. Because many of the patents are not readily available in English, much of the...

Collapse of fiberboard packaging boxes, in the shipping industry, due to rise in humidity conditions is common and very costly. A 3D FE nonlinear model is developed to predict the moisture flow throughout a corrugated packaging fiberboard sandwich structure. The model predicts how the moisture diffusion will permeate through the layers of a fiberboard (medium and facings). The model predicts the deformation response, the loss of stiffness, and the creep response. The FE results are compared with an experimental set-up used at the Forest Product Laboratory in Madison, WI for a panel...

D-Glucose metabolism is thought to be important during wood decay by fungi, not only for anabolic and catabolic purposes of central metabolism, but also as a potential source of peroxide required by extracellular peroxidases. There has been some confusion in the literature as to whether this peroxide-generating activity is of the glucose 1-oxidase or pyranose 2-oxidase (glucose 2-oxidase) type with various fungi or even within the same fungal species. Definitive classification requires accurate identification of the enzymatic products D-glucono- 1,5-lactone and D- arabino-2-hexosulose...

Radiocarbon dating and 40 Ar/39Ar analysis of overlying tephra indicate that plant fossil assemblages exposed by stream erosion and well construction in and near La Selva Biological Station in eastern lowland Costa Rica are Pleistocene in age. We identified plant taxa based on wood, leaves, fruits, seeds, pollen, and spores examined from three sites at ca 30 m elevation. Extrapolating from modern ranges and surface temperature lapse rates suggests paleotemperatures 2.5-3.1°C cooler than at present.

We have reported the use of polyoxometalates (POMs) as selective, regenerable delignification agents that are inherently thermodynamically stable, and self-buffering. The re-activation with oxygen is under conditions that mineralize the organic byproducts of the delignification process. Thus, the POMs provide the basis for a closed bleach plant wherein the consumable oxidant is oxygen and the primary byproducts are carbon dioxide and water. They have been shown to reduce the kappa levels of softwood kraft pulps from 30 to below 5 while retaining viscosity above 20. Recently we have...

Bridges require periodic inspections to ensure the safety of those using the structure. A myriad of techniques have been developed in order to quickly and accurately determine a structure's health. Unfortunately, timber structures are still, in most cases, subjectively evaluated. Decay is one of the most common damage mechanisms in these structures, and often inflicts damage internally, without visible signs appearing on the surface until a timber's load bearing capacity has been largely destroyed. Steel and concrete structures have been successfully evaluated with a variety of dynamic...

Pinyon juniper, a small-diameter and underutilized (SDU) lignocellulosic material, was harvested in New Mexico, identified as Juniperus monosperma at the USDA Forest Products Laboratory, chipped, fiberized and chemically modified to remove pollutants from wastewater. This juniper species was selected as a raw material through screening test for removal of pollutants and proved to be one of a best lignocellulosic material. Resultant fiber was made into a Rando mat using 10% HC-105 binder, with mat density of 0.109 to 0.13 1 g/cm 3 , thickness of about 1.3cm. The hydraulic conductivity was...

Heavy metals from an acid mine drainage (AMD) site were precipitated on the surface of juniper fiber. The modified fiber was tested in lab-scaled batch and column tests and in the field. Elemental analysis showed that soluble iron species deposited on the fiber act as an inorganic adsorbent for anions. Sorption capacity, determined by fitting results to a Langmuir isotherm model, was 2.18 mg/g of Q max for phosphorus removal, which is similar or slightly higher to the sorption capacity of other conventional adsorbents. A pseudo second order kinetic model fitted well for sorption of...

Water contaminated by heavy metals remains a serious environmental and public health problem. Cadmium is a toxic heavy metal that not only causes choking, abdominal pain, anemia, renal dysfunction, and diarrhea, but also has been listed as a carcinogen by the EPA (Gaballah and Kibertus, 1998). Among current technologies used to reduce the amount of heavy metals in water, applications and studies of adsorption method with bio-sorbents have been expanded because of their low cost. (Gaballah and Kibertus 1998; Reddad et al., 2002). Pinyon juniper and modified pinyon juniper have been used as...

Afro-Arabian mammalian communities underwent a marked transition near the Oligocene/Miocene boundary at approximately 24 million years (Myr) ago. Although it is well documented that the endemic paenungulate taxa were replaced by migrants from the Northern Hemisphere, the timing and evolutionary dynamics of this transition have long been a mystery because faunas from about 32 to 24 Myr ago are largely unknown. Here we report a late Oligocene fossil assemblage from Ethiopia, which constrains the migration to postdate 27 Myr ago, and yields new insight into the indigenous faunal dynamics that...