2.3 Freeze-Pump-Thaw cycle

Using this system it is possible to operate freeze-pump-thaw cycles on sample liquids held in any of the three vessels. Procedures appropriate to each vessel are outlined below.

2.3.1 Sample in Vessel 1

All taps and valves should be closed.

Open valve V2 and tap A on Vessel 1, and freeze the sample liquid by slowly raising a dewar of liquid nitrogen around it.

When it has been determined that the liquid has completely frozen switch the pump to roughing mode and open valve V1.

Switch the pump to turbo mode and leave for several minutes. The pressure within the system can be read from the baratron gauge on the pump.

When sufficient pumping has been done and the sample is ready to thaw, close valve V1 and remove the dewar of liquid nitrogen from around Vessel 1.

The system must be ‘let-up’ to atmospheric pressure using helium gas by opening valves V3 and V9. The pressure of gas in the system can be read from the baratron gauge.

Tap B should be closed to prevent suck-back of the liquid as the solid thaws.

The sample can be warmed gently to aid the thawing process and when complete close tap A.

2.3.2 Sample in Vessel 2

All taps and valves should be closed.

Open valve V2 and tap E on Vessel 2 and freeze the sample liquid by slowly raising a dewar of liquid nitrogen around it.

When it has been determined that the liquid has completely frozen switch the pump to roughing mode and open valve V1.

Switch the pump to turbo mode and leave for several minutes. The pressure within the system can be read from the baratron gauge on the pump.

When sufficient pumping has been done and the sample is ready to thaw, close valve V1 and remove the dewar of liquid nitrogen from around Vessel 2.

The system must be ‘let-up’ to atmospheric pressure using helium gas by opening valves V3 and V9. The pressure of gas in the system can be read from the baratron gauge.

Valve V7 should be closed to prevent suck-back of the liquid as the solid thaws.

The sample can be warmed gently to aid the thawing process and when complete close tap E.

- 8 -

Page 8
Image 8
Boca Research None manual Freeze-Pump-Thaw cycle, Sample in Vessel

None specifications

Boca Research, a prominent name in the realm of computer hardware and technology, emerged in the mid-1990s, focusing on developing high-performance peripherals and connectivity solutions. Initially known for their innovative products in the modem and network card markets, Boca Research set a precedent for compatibility and reliability in personal computing.

One of the flagship products of Boca Research was their line of dial-up modems, which became a staple in households and offices as the internet began to gain traction. These modems were designed to be user-friendly and accessible, catering to both novice users and tech-savvy individuals. With features that included plug-and-play installation and robust driver support, Boca Research modems facilitated seamless internet connectivity, contributing significantly to the increasing popularity of online services during the late 1990s.

Boca Research also made significant strides in the production of network interface cards (NICs), which allowed computers to connect to local area networks (LANs). Their NICs were engineered for optimal performance and were often lauded for their stability when handling data traffic. Support for various protocols ensured that users could easily integrate Boca Research's products into existing network infrastructures without compatibility issues.

In addition to these core products, Boca Research expanded its portfolio to include various accessories and add-ons that enhanced the computing experience. This included video capture cards, which allowed users to record and edit video content directly on their computers, and high-quality sound cards that delivered enhanced audio experiences for gaming and multimedia applications.

The proprietary technologies developed by Boca Research placed a significant emphasis on user experience, reliability, and performance. The company was known for its commitment to customer support, ensuring that users received timely assistance and effective solutions to any issues they encountered.

As a pioneer in the peripheral and connectivity market, Boca Research's contributions helped shape the landscape of personal computing during a pivotal time of technological advancement. Their blend of innovation and practicality made advanced technology accessible to users, reflecting a dedication that resonates in the industry even today. Though the company's presence in the market has diminished over the years, its legacy continues to influence many aspects of contemporary computer hardware development.