Temporary connection

Due to the nature of batch operations, transferring and charging of process materials is a common activity. This can entail gas, liquids, and/or solids handling via open equipment. This may include pumping of liquids from drums or dumping of solids from other containers into an open vessel, shoveling material into a dryer, or making temporary connections such as at hose stations. 

Temporary connections offer a lot of flexibility to operations but also creates concerns about increased operator exposure, loss of containment, and the ability to add the incorrect material or charge to the incorrect vessel. 

Portable equipment and temporary connections for processing receive more wear than fixed system. This may lead to hazardous release, ignition or explosion. 

This company s approach was somewhat different than the approach described in the previous incident. The polymer plant implemented a procedure to require force-loaded check valves for backflow prevention on any temporary connection to piping that contained flammables. The check valve had to be rated for the highest design process pressure of either fluid. [8]... 

Remote Access to the infrastructure by staff working from home or third-party support organizations should be carefully managed. Security features such as Call Back, Secure ID, and control of temporary connections to the network should be managed (e.g., only enable a connection when required). 

Pocket ionization chambers are small enough to be worn like a ball-pen. They are charged by a temporary connection to a voltage source, and the residual charge after exposure is read on the scale of an electrometer fitted in the ionization chamber. Pocket ion chambers are not sensitive to a and low-energy f radiation. 

Other temporary connections, such as ketal tethers were also tested. Tebbe olefination of acetate 266 and ketal formation with sugar alcohol 255 lead to tethered intermediate 267, which is cyclized to a C-analog derivative 268 of the a-D-Man(l— 4)-D-Glc disaccharide after ketal cleavage [118] (O Scheme 56). 

Viewed from a historical distance, it seems to me that Pavlov s epoch-making discovery on conditioning changed once and for all scientific thinking about the brain and its self. He experimentally demonstrated, a hundred years ago, that the well-known psychic experience described/defined with the term association objectively refers to the acquisition of a conditioned reflex, the establishment of a new temporary connection between cortical neurons. This was the decisive turn that initiated the objective analysis of behavioral performances. 

Knoll B (1961) Certain aspects of the formation of temporary connections in comparative experiments on mice and rats. Acta Physiol Hung 20 265-275... 

Scheme 10-25 Ester groups can be used as the temporary connection in TVpe II IMDA reactions. Tether length affects the facility and regioselectivity of reaction.

The work, by the Shea group in particular, exemplifies the power of the temporary connection in Type II IMDA reactions not only for controlling the regiochemical outcome of the cyclization but also for exerting absolute stereocontrol. 

The following discussion on the application of the temporary connection to radical cyclizations will be divided into five sections. In the first, a silyl ether is used as the tether in which one of the alkyl groups attached to the silicon possesses the radical precursor (usually a halogen). In the second section, it is the radical acceptor which is introduced on silyl ether formation. The third section concerns the use of silyl acetals as a temporary connection and in the fourth other templating strategies which do not fall into any of the aforementioned areas will be discussed. The final section is a discussion of the use of some of these strategies in C-glycosylation. 

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