A test tube, also known as a culture tube or sample tube, is a common piece of laboratory glassware consisting of a finger-like length of glass or clear plastic tubing, open at the top, usually with a rounded U-shaped bottom. A large test tube designed specifically for boiling liquids is called a boiling tube.

Test tubes are available in a multitude of lengths and widths, typically from 10 to 20 mm wide and 50 to 200 mm long. The top often features a flared lip to aid pouring out the contents; some sources consider that the presence of a lip is what distinguishes a test tube from a culture tube. Some test tubes have a flat bottom; some are made so as to accept a ground glass stopper or a screw cap. They are often provided with a small ground glass or white glaze area near the top for labeling with a pencil.

Bed load aggradations in the headrace channels upstream of a hydropower plant at the Limmat River had required intensive maintenance work. As the bedload transported to the powerhouse can cause both damages to turbines and operational disturbances those aggradations are undesired effects of flood events. Therefore, an alternative solution with vortex capillary tube was investigated in order to obtain an efficient and permanent supply of sediment to the residual flow reach. A vortex tube is a horizontal element below a channel with an intake slot along its longitudinal axis.
As vortex extraction tube are currently not part of a standard design to extract bedload upstream of power plants, a physical model was used to test three different tube configurations in terms of their extracting efficiency, hydraulic behavior and operational criteria.
The hydraulic tests showed that the principle of vortex capillary tube is suited for the extraction of transported sediment. The results demonstrated extracting rates over 95 % under appropriate hydraulic conditions. The extracting efficiency was particularly affected by tube discharge, vortex intensity, channel Froude number and sediment load. In addition, the extraction tube geometry is dependent on sediment size, channel width and economical aspects.
The best results in terms of efficiency were obtained by the tube-type “Omega”. As exposition of the tubes leads to narrowing of the cross-section and flow separation, it is recommended to place the tube’s top edge in the same height as the bed level. For a bended open channel reach a deflection angle of 60° against the main flow direction gave the best

Edmonton-A University of Alberta engineering professor is researching a new method of extracting bitumen from oilsands that uses almost no water and would solve the industry’s toxic tailings ponds dilemma.

Selma Guigard, in the Department of Civil and Environmental Engineering, is developing an Extraction Tube method that uses carbon dioxide and solvents other than water to flush bitumen from oilsands. By comparison, the hot-water Extraction Tube method presently used to mine northern Alberta’s oilsands uses approximately three barrels of water to produce one barrel of oil.

One byproduct of the hot-water Extraction Tube technique is tailings ponds, which contain toxins like heavy metals, and oil. The Syncrude tailings ponds made international headlines this week when some 500 ducks died after landing in one of the ponds.

“I am doing this research because I want to get rid of the tailings ponds, because I want industry to use less energy in mining the oilsands, and I want them to draw less water from the Athabasca River,” said Guigard.

“The recent event of 500 ducks landing on a tailings pond in northern Alberta enforces the fact more research needs to happen to develop new waterless extraction technologies that would avoid creating these tailings ponds.”

Guigard says her experimental technique is similar to the process used to make decaffeinated coffee.

“I know it is a different scale, but we’ve got to be able to do something with the oilsands,” she said.

In applying the method, Guigard mixes carbon dioxide and other solvents with raw oilsands, then heats and pressurizes it. Under pressure, carbon dioxide becomes a “supercritical fluid” that is neither liquid nor gas.

“It isn’t a gas and it isn’t a fluid-it has the best qualities of both,” Guigard said. “It behaves like a liquid solvent but it also penetrates things even better than a gas can; it moves into nooks and crannies and gets at things you couldn’t get at with a conventional solvent.”

Once the new C02-based “solvent” permeates the oilsands sample, the mixture is depressurized and the bitumen separates naturally from the solvent, which is recycled to separate the next batch of oilsands.

“People say ‘You’re using C02, and that’s a greenhouse gas’ but we’re recycling it, and we aren’t generating any C02,” said Guigard.

While the process might require some water to transport oil sands in pipelines to the Extraction Tube process, Guigard says it’s possible that water from the existing tailings ponds could be used, eliminating the need to draw on freshwater resources.

Guigard added that she has been able to successfully extract bitumen from the oil sands and expects that she will be able to extract as much or more than hot-water separation methods do. She estimates that, on a large scale, her Extraction Tube process would probably cost about $20 per barrel, “which is in the ballpark of what is going on right now.”

The engineering professor is currently applying for funding to conduct her research on a larger scale. And she stresses that it would be unreasonable to expect industry to adopt new techniques overnight.

“The challenge is that there is such an infrastructure up there right now,” she said. “It would be a big change but I’d like to see it brought in on a parallel system. I’m saying that 10 years down the road I’d like to see a pilot program operating. But who knows, maybe things could go faster.”

The Research plus has been designed to provide ease of use in accordance with the Eppendorf Physiocare Concept.

As well as being lightweight, risk of RSI is reduced by low aspirating, dispensing, blow-out and tip ejection forces.

The spring-loaded tip cone, fast volume adjustment, plus optimised position and shape of the control buttons and four-digit display make for stress-free workflow.

The Research plus is based on Eppendorf’s Perfectpiston system, made from Fortron.

This organic polymer is resistant to heat, acids and alkalis, mildew, bleaches, ageing, sunlight and abrasion.

It absorbs only small amounts of solvents and resists dyeing.

The result is a pipette that is safe, robust and fully autoclavable, with no need to recalibrate or re-grease afterwards.

The Eppendorf Research plus is available in a choice of single channel, multi-channel and fixed-volume options in different sizes.

It is also simple and quick to calibrate the pipette to handle a dense liquid, such as glycerin, and then recalibrate back to a normal setting.

Features such as the minimal parts design, quick connection clip and individual channel removal on multi-channels facilitate maintenance and reduce lifetime service costs.

This Spring semester, I’m taking Neurobiology, which reasonably, is one of the requirements. I really enjoy the class. The professor is an emeritus of the biology department that has come back to teach this one class, so this would have been a missed opportunity to have Wayne Wiens as a teacher had I not taken the class this year. However, this class has also reminded me of why I am not a straight biology major.

This class is modestly intimidating to me since it has been, gulp, six years since I took Biology my freshman year of high school. Back then, we did the standard frog and squid dissections and as I recall, I experienced the right mixture of uneasiness and morbid excitement during that time. I enjoyed it, but it was the kind of enjoyment that was punctuated by small shimmies slithering up my back.

This last Tuesday, six years later, I had my first Neurobiology lab. Wayne had previewed the work we would be doing during class the day before, but it hadn’t quite registered that frogs would be making a return to my lab life.

The work we were doing that day was to observe the all-or-nothing potential in neurons via stimulation of a frog’s sciatic nerve. We would be using old goat-shockers attached to early iterations of LabVIEW to vary the amount of voltage and duration of stimulation applied to the nerve. But we had to get to the nerve first.

We started by learning our way around the equipment, and learning how to make sharp glass instruments by melting long glass pipette in a Bunsen burner, and pulling the molten glass to narrow it to a fine point. As someone who has always enjoyed watching people do glass pipette, that was particularly fun.

Part way through the lab, Wayne called us over to the sink to get our tools for dissection. He was holding a frog in his hand, and by the time I arrived at the sink, he had decerebrated the frog, which for those who need a refresher on roots means the debraining of that frog. He had severed the brainstem by inserting a pair of scissors through the mouth and…snap.

I got a little bit of a surprise when the remaining frog continued to move. Unbeknownst to me, a frog sans brain is a lot like a chicken with its head cut off: it can still move coordinatedly, even swim in a tray of water and hop out the side. Because those lingering reflexes would distort the data we were meant to be collecting, Wayne disrupted the rest of the spinal connections by running a pipette along the frog’s spinal column.

Beyond this initial shock, the lab was really engaging. I really liked it…in that same morbid fashion as in high school. We found the sciatic nerve, an off whitish string sheathed in myelin that had a tendency to curl up on itself unless you lassoed it with a piece of thread. The nerve stayed live for close to an hour and a half after we first removed the leg from the rest of the frog and hooked it up to the goat-shocker. We watched how it continued to exert contraction control over the gastronemius muscle. It evoked a very physical fascination.

We have two more labs to gather data on this phenomenon, but I doubt my reactions to the first few steps of the lab will change significantly. I can intellectualize my way through it, but I am now rather certain that I won’t find myself in the hands-on medical field anytime soon.

The first stage of making biodiesel is to collect the things you will require. These are:

The oil
A vessel for making the fuel in
A settling tank
A filtering system
95% pure sulfuric acid
99% pure methanol
Prepared mixture of methoxide
Measuring beakers and pipettes
Filter the oil in order to get rid of all particulate matter, like bits of fried food leftovers. Use a number of filtering screens. If you want to avoid this step of the process, you can just buy unused oil.
Heat the oil up to about 60 degrees C for about 15 minutes in order to remove any water that there may be in it. Then, put the oil in a settling tank and let it stand for 24 hours to allow it to separate. Then, either drain out the water from the top or from below.
Next, the oil should be measured precisely and heated until all the solids melt. It is important to measure the oil precisely so that the other ingredients that you put in are in correct proportions.
Then, using a ratio of 8% to the total amount of oil, add methanol that is at least 99% pure. The higher the purity of the methanol, the better.
Keep blending the methanol in the oil for about five minutes. At this stage of the procedure the mixture of oil and methanol will look cloudy.
Next, for every 1-liter of oil, add 1 ml of 95% pure sulfuric acid. Remember to be very careful, taking every safety precaution, while handling sulfuric acid, because it can be extremely dangerous.
Heating this mixture up to 35 degrees C, keep stirring it. Then, remove it from the source of heat and keep stirring it gently for 2 more hours. Then let it rest for about 8 hours.
After that, if you find that any of the mixture has solidified while it had been resting, reheat it lightly. Then, put half of a 12% volume methoxide mixture into it and stir for 5 minutes.

Non-piston driven vacuum assisted pipettes are hollow narrow cylinders which work like a straw and require the use of some kind of additional suction device. Originally pipettes were made of pyrex glass, but currently are made of polystyrene. It is more commonly used in chemistry, with aqueous solutions. There are two types. One type, the volumetric pipette, has generally a large bulge with a long narrow portion above with a mark as it is calibrated for a single volume. Typical volumes are 10, 25, and 50 mL. Alternatively, graduated pipettes are straight-walled, and graduated for different volumes such as 5 mL in 0.5 mL increments. The single volume pipette is usually more accurate, with an error of ± 0.1 or 0.2 mL.

The pipette is filled by dipping the tip in the volume to be measured, and drawing up the liquid with a pipette filler past the inscribed mark. The volume is then set by releasing the vacuum using the pipette filler or a damp finger. While moving the pipette to the receiving vessel, care must be taken not to shake the pipette because the column of fluid may “bounce”.

A daylight reloadable lighttight plastic cassette for holding and dispensing a roll of light sensitive material is formed of a hollow open-ended tubular housing having lighttightly mating hingedly connected base and lid sections which pivot apart on the hinge to open the housing, A dispensing slot lighttightly sealed, e.g. by plush fabric, is present on the housing side opposite the hinge, preferably defined between suitably spaced longitudinal edges of the housing sections. The opposite housing ends are lighttightly closed by end caps, each molded in two mating sections, which are telescopingly fitted on end margins of the housing sections. The end cap sections can be carried by the respective housing sections to pivot therewith in clam-shell fashion. The housing sections can be latched in closed position, preferably with latches engaging the end cap sections. Alternatively, the end cap sections for each end cap can be hinged together with one section anchored on a housing section while the other cap section is flippable on the hinge laterally of the end cap to free the other housing section for opening the housing.

Swabs are commonly used for sample extraction from a variety of sites, and for the subsequent detection of infectious agents (bacteria, fungi, or viruses). After the swab procedure, the infectious agents are typically released into a culture medium or onto a culture plate.

Modern molecular biology methods, such as the detection of bacteria or viruses by polymerase chain reaction (PCR) require a different approach in the downstream handling of the swab. The goal is to recover as much of the material adhering to the swab as possible without further diluting it and without introducing potentially inhibitory substances.

Product Description

Roche Applied Science has developed a highly convenient plastic disposable that can be used to recover adhering material from a swab using a very straightforward procedure: the S.E.T.S., an acronym for Swab extraction tube System (Figure 1).

The S.E.T.S. is designed to hold standard swab tips (approximately 5 8 mm in diameter and 1025 mm in total length) in the Inner tube (1). The Inner tube has a hole with a defined diameter on the bottom. The lid is then closed, and the loaded Inner tube is placed into the Collection tube (2). The assembled device is now placed in a standard benchtop centrifuge for a brief spinning down of the adherent material from the swab through the hole in the Inner tube. After spinning down the material, the closed Inner tube with the swab is discarded.

Automatic tube pullers designed for the fast and effective refurbishment of heat exchangers, air-conditioning and refrigeration plant systems can be supplied by Wicksteed Engineering.

The equipment is suitable for the withdrawal of tubes up to 45mm diameter, with a pulling force of up to 30t being available.

Designed for one-man operation, the pullers provide significantly faster tube removal rates than competitive products.

In addition, models are also available to enable safe operation in hostile environments if required.

A powerful electrohydraulic unit can be supplied for general-purpose applications in nonhazardous atmospheres including power generation, sugar and aluminium refineries together with desalination plants.

With the highest rate of tube extraction, these products are ideal for general engineering requirements and guarantee minimum equipment downtime for all tube renewal and replacement projects.

However, where hostile environments may be encountered, as in oil refineries and petrochemical plants, then a pneumatic-hydraulic tube puller has been developed.

This obviates the need for ‘hot work’ permits.

These tube pullers are fully automatic and easy to use, with no special skills required for operation.

They feature a unique patented locking device to eliminate operator involvement during the pulling process.

There is a simple two-button on/off operation, with sensing devices incorporated to determine the appropriate extraction force required.

The pulling heads have strokes of 150mm and tube extraction rates in excess of 3m/min can be achieved, using an automatic step-and-repeat action.

Both power packs feature 5.5kW motors.

They are fully mobile and at 305kg (including hydraulic oil) can be easily transported.

The electro-hydraulic unit requires a 415V three-phase 50Hz supply, while the pneumatic-hydraulic unit needs a 7bar input air pressure with a minimum volume of 3680 litre/min.

A 220V 60Hz model is also available for the American market.

Tube expanders are also available as the most effective way of securing tubes into the end plates, complementing the product range from what is probably the UK’s largest manufacturer of tube expanding equipment.