Kinds Of Inserts Research Articles

The simulation and experimental study of granular materials discharged from a silo with the placement of inserts

The simulation method of DEM and experimental method are used to investigate the flow pattern of the filling and discharging process for two-dimensional plane silos. Two kinds of inserts (conical insert and BINSERT®) are used in the silo to change the flow fields of the silo. The placement of inserts improves the flow behaviors of funnel flow type to mass flow type during discharging. The wall normal stresses are influenced by the change of the flow type. The effects of using differently shaped inserts on the flow pattern and wall stress are analyzed in this study. The controlling parameters include the silo half-angle, the orifice width, the shape of the insert and the properties of the granular materials. The simulation and experimental results are in good agreement.

The prophage of SP beta c2dcitK1, A defective specialized transducing phage of Bacillus subtilis.

The defective specialized transducing phage SP beta c2dcitK1 carries two known bacterial genes, kauA and citK, as well as SP beta hage markers including the heat-sensitive repressor allele, c2. Some phage genes (including essential ones) are missing. When SP beta c2dcitK1 transduces SP beta-sensitive cells of Bacillus subtilis, the defective prophage is inserted into sites in the homologous bacterial DNA of the attSP beta-kauA-citK region of the recipient chromosome. During the growth of these transductants, occasional excisions occur that result in the loss of the phage genes and of the heterogenotic state. These excisions increase greatly in frequency during growth at repressor-inactivating temperatures. The kinds of insertions and excisions seen suggest that a Campbell-type (CAMPBELL 1962) circular phage genome may occur transiently. If the transductants are superinfected by SP beta c2 or by the clear-plaque mutant SP beta c1, the resulting double lysogen can be heat induced to release high-frequency-of-transduction (HFT) lysates for kauA and citK.

Two kinds of insertions in bacterial genes.

Six insertion mutations in the gal operon of E. coli and two insertion mutations in the xycIIOP operon of bacteriophage lambda were tested for homology by annealing separated strands of lambda dgal DNA carrying the insertions, and inspection in the electron microscope. Class 1, consisting of the gal mutations OP 128, OP 141, T-N 116, OP 306, T-N 102 and the lambda mutation r14 are about 800 nucleotide pairs long, completely homologous and not circularly permuted. The first three insertions of class 1 are integrated in one direction with respect to the adjacent genes, the other three in the opposite direction. The DNA inserted in this class of mutations is called IS1. Class 2 consists of the gal insertion OP 308 and the lambda insertion r32. They are about 1400 nucleotide pairs long. The two are integrated in opposite direction with respect to the chromosome of λdgal. The DNA in insertion mutations of class 2 will be called IS 2. IS1 and IS2 do not share any detectable homology. These data are supported by cross-hybridization experiments using RNA transcribed in vitro from lambda dgal or lambda DNA carrying one insertion and DNA carrying either the same or a different insertion. Similar results were obtained by Malamy, Fiandt, Szybalski and Fiandt, Szybalski, Malamy (accompanying papers).

Die Beeinflussung des Fliessens von Kalkesteinsplitt in einem Schachtofen durch Einbauten über dem Austrag

When starting the burning of lime with a new type of shaft kiln, an unequal quality of lime was observed. It was demonstrated by experiments that the unequal velocity of flow in the kiln caused the changing quality of lime. Therefore, experiments with a model of a shaft kiln were started, in order to obtain an equal distribution of velocity. The scale of the model was 1: 2,83. The choice of the scale is explained and a description of the model given. The experiments were made by using coloured pieces of lime stone for measuring the time that was necessary to pass through the kiln. The effect of several kinds of inserts was tested. The result of each experiment is described by one factor, that gives a measure for the equal distribution of velocity referred to its plane in the cross section of the kiln. The conformity between the model and the original kiln will be discussed. The success of changing the inserts in the original kiln will be shown by an improved quality of burned lime. In an attempt to improve results, the path of the lime stone in the shaft kiln was found. It seems possible to get a further improvement by relating the velocity of lime stone to the distribution of temperature in the shaft kiln.