Evaluation of the portable furrow infiltrometer
Abstract Twenty infiltrometer tests were conducted to compare infiltration rates estimated by the recirculating infiltrometer (RIF) and the newly developed portable infiltrometer (PIF). Two types of furrows commonly used in the western United States; small and steep, and large and less steep; were considered in high and low infiltration soils. Comparison of the PIF and RIF infiltration rate measurements indicated that PIF was most accurate in estimating steady infiltration rates. Use of the PIF for predicting infiltration rate functions was not recommended because of the need for collecting accurate measurements early during the infiltration process. Considering ease of installation, accuracy in measuring steady infiltration rates, and ability to collect data during irrigation, the PIF is a promising device for use in surface irrigation management.
Recirculating furrow infiltrometer design guide
Determination of infiltration parameters is critical for the design and 
operation of efficient furrow irrigation systems. The complexity of the physical 
processes which govern infiltration in furrows, and the nonhomogeneous, anisotropic 
conditions which often exist in irrigated fields, have hindered the development of an 
infiltration theory which can accurately predict infiltration rates based on easily 
measured soil parameters. Therefore, the practicing irrigation engineer continues to 
depend on direct measurement of infiltration using infiltrometers or volume balance 
methods for determining field infiltration during continuous flow or surge flow furrow 
irrigation. Volume balance methods use advance, surface storage, inflow, and outflow 
data collected during an irrigation event to determine the infiltration parameters. 
Elliott and Eisenhauer (1983) outline the details of several volume balance methods for 
continuous flow irrigation. Latortue (1984) outlines a volume balance technique for 
estimating infiltration and surface storage for surge flow irrigation. The infiltration 
parameters determined from these methods are likely to be more representative of 
average field conditions than data obtained from an infiltrometer.
Increasing pulp yield in kraft cooking of softwoods by high initial effective alkali concentration (HIEAC) during impregnation leading to decreasing secondary peeling of cellulose
Abstract Pulp yield can be improved by a more homogeneous delignification of the chips, achieved by improved impregnation prior to the cooking stage. Complete and efficient impregnation is obtained by increasing the diffusion rate by means of an impregnation liquor with a high initial effective alkali concentration (HIEAC). In the present study, the effect of HIEAC in the impregnation was evaluated and compared to a reference impregnation procedure and a prolonged impregnation. After the various impregnation scenarios, the alkali concentration was always adjusted to the same level in the beginning of the cooking stage. Impregnation with a HIEAC resulted in yield improvements by 1–1.5% units, due to a higher cellulose yield and possibly also to higher yield of glucomannan. The HIEAC with an even alkali distribution within the chips prior to the cooking stage resulted in a more uniform delignification carbohydrate degradation. Yield increase obtained by uniform delignification is due to both decreased shives content as well as less secondary peeling.