Disassembly Procedures Research Articles

Returning perchlorate-contaminated fume hood systems to service. Part II. Disassembly, decontamination, disposal, and analytical procedures.

Part I presented work leading up to and including a pilot study for remediation of laboratory fume hood systems contaminated with residues from processes that used fuming perchloric acid. Since publication of Part I, three incidents involving explosions and fires related to perchlorates have come to the attention of the authors. Experience has been gained through decontamination/remediation of 41 additional systems. This article expands on previous one and includes (1) administrative details that need to be addressed before and during the execution of the decontamination itself, (2) a seven-step procedure for decontamination-remediation/disposal, (3) some precautions associated with the use of methylene blue as a diagnostic tool for perchlorates, and-specific electrode to augment or replace the methylene blue test.

Development of Machine-Maintenance Training System in Virtual Environment

The periodical inspection of nuclear power plants is indispensable in their operations. However, it requires a lot of workforces with a high degree of technical skill in assembling and disassembling various sorts of machines in hazardous environment. In this study the authors are developing a machine-maintenance training system in virtual environment which can be used easily by beginners. In this paper the system configuration is outlined. And proposed are recognition algorithms of natural gestures, which differ with trainees, and also a method for representing assembly and disassembly procedures by using Petri net.

Assembly sequences planning for simultaneous engineering applications

This paper describes a Generative Assembly Process Planner (GAPP) used to generate and evaluate assembly sequence alternatives which can be used in simultaneous engineering applications. Given a graph model of the product to be assembled, optimal assembly sequences are automatically generated and evaluated in a single process. Geometric feasibility and accessibility constraints on assembly operations which help prune the search space are presented. Assembly-related criteria which guide the search to an optimal solution are described. These include: number of reorientations, concurrent execution of assembly tasks, grouping of similar tasks and stability criteria. The relative weights of various criteria can be varied interactively resulting in different optimal assembly sequences. The ability of GAPP to generate and evaluate assembly alternatives when various criteria are enabled or disabled or their relative importance is changed makes it an effective tool for simultaneous engineering/manufacturing applications. Examples are included to demonstrate GAPP's use and potential for assessing assembly, disassembly, repair and maintenance procedures.

Partial reconstitution of 60S ribosomal subunits from yeast

Ribosomal 60S subunits active in polyphenylalanine synthesis can be reconstituted from core particles lacking 20-40% of the total protein. These core particles were obtained by treatment of yeast 60S subunits with dimethylmaleic anhydride, a reagent for protein amino groups. Upon reconstitution a complementary amount of split proteins is incorporated into the ribosomal particles, which have the sedimentation coefficient of the original subunits. Ribosomal protein fractions obtained by extraction with 1.25 M NH4Cl, 4 M LiCl, 7 M LiCl, or 67% acetic acid, are much less efficient in the reconstitution of active subunits from these core particles than the corresponding released fraction prepared with dimethylmaleic anhydride. Attempts to reconstitute active subunits from protein-deficient particles obtained with 1.25 M NH4Cl plus different preparations of ribosomal proteins, including the fraction released with dimethylmaleic anhydride, were unsuccessful. Therefore, under our conditions, of the disassembly procedures assayed only dimethylmaleic anhydride allows partial reconstitution of active 60S subunits.

37] Isolation of tubulin from nonneural sources

Publisher Summary This chapter presents the procedure for isolation of tubulin from nonneural sources. The major impetus for isolating tubulin (TU) from nonneural systems did not come until after the successful isolation, by in vitro reassembly, of TU from vertebrate brain. Largely for this reason, methodologies developed for the isolation of nonneural TUs are based upon the assembly–disassembly procedures for vertebrate brain TUs. An alternative purification method has been developed for human platelet TU, which has the advantages of speed, high TU yields, and purity, is Rabbit anti-TU was raised by injection of two-cycle-purified pig platelet TU. The regimen consisted of an initial intramuscular injection of 400μg of TU followed by three booster injections each of 400 μg of TU at weekly intervals. The γ-globulin serum fraction is isolated ammonium sulfate precipitation and preabsorbed with homologous serum proteins and MT-associated proteins (MAPs). Monospecific anti- TU antiserum is covalently linked to 1.0 g of N-hydroxysuccinimide-activated BioGel A-15 m by incubation in 25 ml of 0.1 M phosphate buffer. From 7 mg of crude platelet extract added to a 12 × 1.5 cm TU affinity column of this resin, 0.2 mg of assembly-competent TU can be obtained.