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Metal-CO2 propulsion is less known than in-situ resource utilization (ISRU) technologies. This concept, based on using Martian carbon dioxide as an oxidizer in jet or rocket engines, offers the advantage of no chemical processing for CO2 and thus requires less power consumption than ISRU alternatives. In this paper, we study the burning behavior of the Mg in a CO2 atmosphere to assess the feasibility of using Mg/CO2 reactions as an in situ resource utilization technology for rocket propulsion and energy generation on other planets. From the experimental results, we can see that the critical ignition temperature increases with increasing the particle size and decreases with increasing the ambient pressure. In the CO2 atmosphere, we found the complicated sequence of interaction modes including pulsating combustion in a wide range of ambient temperatures. The pulsation frequency is determined by the sample temperature at the phases of slow heterogeneous combustion between the flashes. The combustion mechanisms are discussed with consideration of processes in both a surface film and gas phase.

. A second expressed kininogen gene in mice. Physiol Genomics 26: 152-157, 2006; doi:10.1152/physiolgenomics.00244.2005.-We isolated PCR, RNA ligase-mediated rapid amplification of cDNA ends (RLM-RACE-PCR)-, and RT-PCR-generated clones from mouse kininogen family transcripts. DNA sequencing indicated that the clones were from two distinct genes. One set (K1) is from the previously reported mouse kininogen gene. The second set (K2) has an open reading frame, is 93% identical to K1 in the overlapping nucleotide sequence, and, unlike T-kininogens in the rat, encodes a bradykinin motif identical to K1. We discovered that K2 exists with two different 5Ј ends. We used RT-PCR to determine the distribution and relative abundance of K1 and K2 mRNA in mouse tissues. K2 is transcribed and K1 and K2 are generally both expressed in the same tissues; however, they differ in their regulation of the alternative splicing event that yields either low-molecular-weight kininogen (LMWK) or high-molecular-weight kininogen (HMWK). For example, in the liver K1 is expressed as both HMWK and LMWK, whereas K2 is only expressed as LMWK. Conversely, in the kidney K2 is strongly expressed as both HMWK and LMWK, whereas K1 is not expressed as HMWK and expressed only very weakly as LMWK.polymerase chain reaction; DNA sequencing; alternative splicing KININOGENS ARE PROTEIN SUBSTRATES for tissue and plasma kallikrein. When cleaved, they release kinin peptides that function as vasodilators and are involved in the cardioprotective effect of angiotensin-converting enzyme inhibitors. Mammals produce two types of kininogens, termed high-molecular-weight kininogen (HMWK) and low-molecular-weight kininogen (LMWK). Both HMWK and LMWK mRNA are encoded by the same gene via 1) alternative RNA splicing in exon 10 and 2) the use of different polyadenylation sites, resulting in the generation of two distinct types of kininogen mRNA.Bovine, human, rat, and mouse LMWK and HMWK cDNAs have been cloned and sequenced (4, 5, 9). The sequences of the two additional kininogen family genes unique to rats, called T-kininogens, have also been determined (2). T-kininogens exist only as LMWK; they are not substrates for tissue and plasma kallikrein and do not have a standard bradykinin motif, but rather T-kinin (Ile-Ser-bradykinin). In addition, T-kininogens have a remnant noncoding DNA sequence that is homologous to the exon 10 HMWK-specific region of rat kininogen.Previously, only a single kininogen gene has been identified in all species studied except for rats. Although a previous report indicated that mice likely have only a single kininogen gene (10), we (3) and others (1) have reported the discovery of a second expressed kininogen family gene in this species. Here we further examine this second kininogen gene's sequence and expression. METHODSInitial generation of mouse HMWK-specific PCR fragments. PCR primers specific to the mouse kininogen exon 10 HMWK region (primer set A) were chosen by homology among rat, mouse, and human HMWK DNA; where they differed, the mou...

The coupling effect of physics, chemistry and mechanics is through charring layer in the process of ablation of the insulation material. Description of the structure and mechanical properties of charring layer is the critical factor to numerical computation for foretelling the ablation of insulation material. The characteristic of charring layer structure of EPDM insulation at sorts of ablating condition were analyzed, and based on characteristic of porous medium of charring layer, the mechanical model with porosity as parameter was modeled by using theory of solid porous medium. According to the intensity determination of charring layer, the coefficient of intensity model was determined, then, the failure criterion of charring layer was set up, which can provide the mechanical parameters of charring layer for numerical computation to foretell the ablation of insulation material.

Gas-steam launching system with water injection in block can overcome the problem of horizontal or large-angle launching, and gets more and more value in recent years. Based on the characteristic of launching system, the model was built with several assumptions, which could provide reference and technique for developing the new launching system. And the generator result was verified by the experimental one. The interior ballistic characteristics were researched by calculation result under different deep and injection water mass conditions. The comparison of the simulation results and theory analysis indicates the model was rational and valid, and different launching deep and cooling water mass had effect on ballistics, more water can cool down the silo, but also brings more energy loss, and deeper launch needs more energy, so good design is required to fit the parameters demand in all respects.