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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...

Several fixation systems to limit or decrease boron leachability from treated wood have been developed. Some attempts have relied on limiting of water penetration of treated wood using water repellents, monomer and polymer systems. On the other hand, non-toxic polymers such as proteins were tried to reduce amount of boron leached from wood (Thevenon et al. 1997, 1998). Their results showed that protein borates such as albumin and soja protein borates greatly retarded the leaching of boron from treated wood via formation of salt. In addition, precipitation of boron in wood via a calcium...

An Excel spreadsheet developed to solve the ion-exchange equilibrium in wood pulps has been linked by dynamic data exchange to WinGEMS and used to model the non-process elements in the hardwood bleach plant of the Mead/Westvaco Evandale mill. Pulp and filtrate samples were collected from the diffusion washers and final wash press of the bleach plant. A WinGEMS model of the bleach plant was tuned to match the mill data using the sodium and chloride analysis. The spreadsheet was then activated to calculate the bound and free concentrations for H+, Na+, Mg2+, Ca2+, Mn2+, and Ba2+. It adjusted...

Pinyon juniper, Juniperus Monosperma, is a small-diameter and underutilized (SDU) lignocellulosic material. Evaluated were efficacy of base-treated juniper fiber (BTJF) sample for cadmium (Cd 2+ ) sorption and the viability of juniper fiber as a sorbent for the removal of Cd 2+ from water. Fourier Transform Infrared Spectroscopy (FTIR) analysis indicated that carboxylate ion is a major functional group responsible for Cd 2+ sorption and the apparent ideal sodium hydroxide (NaOH) concentration for the base treatment was approximately about 0.5 M. From the batch sorption isotherm test, it...

In an effort to encourage the development of value-added engineered applications for small diameter round timber, research is being conducted at the US Forest Products Laboratory to develop and verify design guidelines for connections with specific application to round timbers. The objective of this work is to provide potential users with a number of viable connection options applicable in the fabrication of engineered, round-wood structural components and systems. Target uses include trusses, built-up flange beams and space frames. This paper presents information on a mortised steel plate...