Six laboratory scale biogas mixed anaerobic digesters were operated to study the effect of biogas recycling rates and draft tube height on their performance. The digesters produced methane at 0.40-0.45 L per liter of digester volume per day. A higher methane production rate was observed in unmixed digesters, while increased biogas circulation rate reduced methane production. However, different ...

Comment The fall in differences in height between groups varying in intelligence and educational level is probably attributable to changing social factors,perhaps specifically a greater homogeneity of nutritional conditions across different social classes. In earlier data we found that the social class of parents correlated with the intelligence (0 32) and educational level (0 42) of their chil...

A two-year field study was conducted to investigate the performance of a lightweight trash-board moldboard plow (with and without a trash-board), as influenced by stubble height and water content. Both fields were measured for the performance of a trash-board moldboard plow when used during the optimization of the plowing depth, the water content, and the reaction forces. The results showed tha...

childhood energy intake and subsequent risk of cancer was also confined to cancers unrelated to smoking. Most previous studies have either grouped all cancers together or looked only at individual cancers. However, consistent with our results, the physicians health study found a positive association of height with all malignant neoplasms but not with lung cancer. In line with extensive animal e...

Adult height has been found to be inversely associated with mortality. Recently, it has been suggested that growth in utero is linked with adult risk of several chronic diseases. The authors examined possible associations between birth weight, birth length, and adult height in young Danish men. They conducted the study in the fifth conscription district of Denmark including all the men born aft...

A shower cooling tower (SCT) operates without fill because of salt decomposition on the fill that leads to deterioration of conventional cooling tower performance. This study presents a two-dimensional mathematical model for energy and exergy analysis of multi-diameter droplets and air interaction along with the height of the forced draft SCT, to predict the exit condition of water droplet for ...

the chisel plow is one of the tillage implements utilized to carry out conservation tillage practices; therefore, it is valuable to pay more attention on the force requirement of this implement. to achieve this goal, a theoretical model was developed to calculate draft, specific draft, and drawbar power of a chisel plow. then, results obtained from the developed model were compared with the rep...