BACKGROUND Maintaining the quality of clinical specimens for tuberculosis (TB) testing is a major challenge in many high TB burden-limited resources countries. Sample referral systems in low and middle income countries are often weak and the maintenance of the cold-chain challenging and very costly for TB programs. The development of transport media allowing the preservation of samples without ...

When we design a valve system there are many design factors and their values to decide. Generally, design factors which affect the whole performance of compressors are strongly related to each other so we can't decide the value of each design factors respectively. In order to decide the optimum value (among levels) of those factors simultaneously and reduce the number of experiments we applied ...

A refrigeration system which was originally designed using R502 as refrigerant was rebuilt to adapt the special requirements of R404A. The experiments, both for R502 and R404A, on this system were done and some parameters such as evaporating temperature, condensing temperature, discharge temperature, compressor input power and so on were measured under different working conditions. Then the ope...

HFCI34a was selected for the alternative refrigerant for CFC12 because of its excellent properties like thermodynamics. But there were several problems like immiscibilitiy with oil to replace CFC12 by HFC134a. In order to solve these problems, we developed new polyol ester refrigeration oil which had good miscibility with HFC134a and excellent thermal stability and lubricity as well. To apply p...

Benchmark refrigeration systems in the road transportation sector are powered by diesel, having operation costs of up to 6,000 €/y with the consequent increase of the goods cost. This chapter presents an alternative refrigeration system based on fuel cells (FC) and hydrogen as fuel, with higher efficiency, reduced costs and independent of diesel price fluctuations. Examples of the energy load p...

Refrigeration service personnel have used leak detection equipment for years when servicing refrigeration equipment. In the past, leak detection typically was only concerned with leak pinpointing, either with an ultrasonic device, soap bubbles, dyes, thermal conductivity, or other electronic devices. Today, refrigerant leak detectors exist not only for pinpointing leaks, but also for monitoring...

Single staggered is a design development of normal wire and tube heat exchanger that wires are welded with staggered configuration on two sides. Capacity of wire and tube heat exchanger is the ability of the heat exchanger to release heat. The objective of this study is to analyse the effect of wire pitch (pw) on capacity of single staggered wire and tube heat exchanger. The research...