Abstract: An approach is provided that receives event data that correspond to detected activities performed by a user on one of a set of one or more computer systems. The detected activities are performed by the user over a time duration. The approach analyzes the event data using time-based models. Each of the time-based models correspond to a different time interval that is included in the time duration. The analysis results in time-based risk scores pertaining to the user for each of the different time intervals. An action is then performed based on an overall security risk score of the user with the overall security risk score of the user being calculated based on the different time-based risk scores.

Abstract: The present invention relates to a method to dispose plant cellulose materials, in particular to a method for preparing a main hydrolysate by hydrolyzing the plant cellulose materials with concentrated sulfuric acid. The plant cellulose materials are mixed with sulfuric acid in batches, and the main hydrolysate is obtained after hydrolysis. The batch mixing includes the following procedures: (1) sulfuric acid solution is used to dissolve part of the plant cellulose materials thereby forming a hydrolysate; (2) when the plant cellulose materials can not be dissolved any more, concentrated sulfuric acid with the concentration more than 80 wt % is successively added into the hydrolysate, and another part of the plant cellulose materials are added; (3) and then the procedure as step (2) is repeated until all the plant cellulose materials are completely hydrolyzed.

Abstract: A method for recovering sulfuric acid from concentrated acid hydrolysate of plant cellulose material is disclosed. In some of the examples, the concentrated acid hydrolysate is mixed with a liquid organic precipitant, with the sugars in the hydrolysate being precipitated and separated out. The remainder is sulfuric acid and an organic solvent solution. The organic solvent is then separated by distillation or extraction, thereby obtaining the pure sulfuric acid solution. This precipitation method can recover above 90% sugars and acids with a small amount of organic precipitant, which greatly reduces the recovery cost.

Abstract: A method for recovering sulfuric acid from concentrated acid hydrolysate of plant cellulose material is disclosed. In some of the examples, the concentrated acid hydrolysate is mixed with a liquid organic precipitant, thereby the sugars in the hydrolysate is precipitated and separated out, and the remained is sulfuric acid and an organic solvent solution. Then the organic solvent is separated by distillation or extraction, thereby obtaining the pure sulfuric acid solution. This precipitation method can recover above 90% sugars and acids with a small amount of organic precipitant, which greatly reduces the recover cost.

Abstract: The present invention relates to a method to dispose plant cellulose materials, in particular to a method for preparing a main hydrolysate by hydrolyzing the plant cellulose materials with concentrated sulfuric acid. The plant cellulose materials are mixed with sulfuric acid in batches, and the main hydrolysate is obtained after hydrolysis. The batch mixing includes the following procedures: (1)sulfuric acid solution is used to dissolve part of the plant cellulose materials thereby forming a hydrolysate; (2)when the plant cellulose materials can not be dissolved any more, concentrated sulfuric acid with the concentration more than 80 wt % is successively added into the hydrolysate, and another part of the plant cellulose materials are added; (3)and then the procedure as step (2) is repeated until all the plant cellulose materials are completely hydrolyzed.