Oil return from the evaporator to the compressor suction port is an important requirement. It is affected by the refrigerant/lubricant properties, gas velocities and piping geometry. The refrigerant R -134a has successfully replaced R-12 in household refrigerators and freezers. This paper describes a test method to estimate the mean oil film thickness and to observe the flow pattern in vertical...

Evaluation of cold chain system was done in a time bound study during August and September months of 1992 in two districts of Haryana as there were frequent breakdowns of icelined refrigerators during the previous year. The study revealed that defective stabilizers and electricity plugs and sockets were the reason of breakdown in many cases. Temperature maintenance and functioning of deep freez...

The suspensions in normal saline showed almost four log fall in 1 month of storage. However, subsequently there was no marked fall in the viability during an observation period of 12 months. Initial fall in viable count from 109 to 105 CFU/mL at the end of 1 month is possibly due to accumulation of lethal metabolites and/or depletion of nutrients.[4] However, the subsequent loss in viability in...

Convenience stores with refrigerated display cases are ubiquitous in much of the developed world. For such buildings it is common to utilize multiple rooftop units (RTU) to serve the retail area and multiple coolers or freezers to provide cooling for merchandise. The overall objective of this paper is to develop and assess an integrated control approach for typical convenience store application...

Urban district heating and cooling (DHC) systems operate large freezers, heat exchangers, and boilers to stably and economically supply hot and cold water, steam etc., based on customers demand. We formulate an operation-planning problem as a nonlinear integer programming problem for an actual DHC plant. To reflect actual decision making appropriately, we incorporate contract-violation penaltie...

The study presented here explores eating as a pedagogical practice by paying attention to arrangements of things such as Christmas cookies, whole-wheat and white bread, frozen chicken, plates, chairs, tables, and freezers. Through a series of ethnographic research examples from German and Brazilian preschools, it investigates how eating in the kindergarten can be a sensual pleasure, a health ri...

Advances in genetics, proteomics and cell biology over the past 20 years have unearthed a multitude of potential macromolecular targets for the selective treatment of disease. The challenge remains to find appropriate small molecule ligands for these proteins (or nucleic acids), and to use these ligands to validate novel disease targets. The advent of low-cost instrumentation has made industria...

The standard method for the storage and preservation of RNA has been at ultra-low temperatures. However, reliance on liquid nitrogen and freezers for storage of RNA has multiple downsides. Recently new techniques have been developed for storing RNA at room temperature utilizing desiccation and are reported to be an effective alternative for preserving RNA integrity. In this study we compared fr...

Maintaining the long-term integrity of nucleic acids in the laboratory has traditionally required the use of freezers. However, novel nucleic acid stabilization technologies may allow for the storage of DNA and RNA at room temperature in a cost-effective, environmentally friendly manner. In this study, we evaluated two novel products for room temperature DNA storage: Biomatrica's DNA SampleMatr...