urea is the most common form of nitrogen fertilizer used in sugar beet cultivation. urea has a high solubility and its losses are high and consequently its efficiency is low. it is supposed that urea solubility can be limited and its efficiency can be increased by using slow-release nitrogen fertilizers. by conducting an experiment in three important sugar beet cultivation areas of khorasan pro...

in this study, the particleboard was made with rice husk and urea formaldehyde resin of 7, 8, 9 and 10 percent (based on dry weight of rice husk). to improve mechanism of bondability a definite amount of isocyanate resin is introduced to replace the same amount of urea formaldehyde resin. the effect of urea formaldehyde resin and diisocyanate content on bondability was evaluated by studying the...

Glycolaldehyde, produced from cracking of glucose, was tested as a substitute for formaldehyde in urea-based wood adhesives. Initially, different parameters (water content, aldehyde/urea-ratio, curing temperature, and time) were screened to identify the optimal conditions providing highest bond strength. Afterwards, system reformulated 2-component compared urea-formaldehyde system, which showed...

Maritime pine (Pinus pinaster) sawdust was used to produce liquefied wood by the polyhydric method with acid catalysis. The process was optimized to produce the highest amount of liquefied wood. Wood liquefied at 160oC for 90 min was used in the adhesion tests. The bond strength of veneer glued with ureaformaldehyde and melamine-urea-formaldehyde resins and several mixtures of liquefied wood wi...

Nitrogen is the most important essential nutrient that plays a major role in achieving maximum crop yield in agriculture. Therefore, nitrogen fertilizers such as ammonium sulfate and urea have been extensively used in modern agriculture. These fertilizers are generally oxidized to nitrate via nitrite by nitrifying microorganisms in the agricultural field (4, 10, 11). The serious environmental p...

Several techniques have been used for sand production control in sandstone reservoirs.The main objective of this research is to present a suitable resin to be used as a consolidation agent in oil reservoirs. To achieve this purpose, urea-formaldehyde resin, phenol-formaldehyde resin, and modified urea-formaldehyde resin were selected to be studied. Core samples were made by the sand sample prov...

Abstract Soy flour can be substituted in polymeric diphenylmethane diisocyanate (pMDI) resin for bonding plywood. Resin bleed-through is avoided by prepressing at 95°C. The boards have greater wet and dry strength than do those prepared from melamine-urea-formaldehyde (MUF) resin. also emulsion polymer isocyanates cold-press applications. soy increases but keeps the unchanged. optimal level of ...

partial replacement of formaldehyde with furfural in the urea-formaldehyde resin on the formaldehydeemission, physical and mechanical properties of particleboard was investigated. the modulus ofrupture (mor), modulus of elasticity (moe), internal bond (ib), water absorption (wa), thicknessswelling (ts) and formaldehyde emission (fe) of poplar particleboards made with the modifiedresins were mea...

Approximately 1 million metric tons of urea-formal-dehyde resin are produced annually. More than 70% of this urea-formaldehyde resin is used by the forest products in-*This information was written and prepared by a U.S. Government employee on official time and it is, therefore, in the public domain and not subject to copyright.