LPG CYLINDERS ROAD TRANSPORT SAFETY PROCEDURES BASICS AND TUTORIALS

Procedures for safe transport of LPG cylinders by road.

Transport
• Carry cylinders on open vehicles. Keep cylinders upright and adequately secured, e.g. with a rope.
• Keep a fire extinguisher, e.g. 1 kg dry power, in the cab to deal with any small fire, e.g. an engine fire.
• Do not leave cylinders on vehicles unsupervised.
• Ensure that the driver has received adequate training and instructions about the hazards of LPG, emergency procedures, driver duties, etc.
• Ensure that relevant information is readily available on the vehicle, e.g. on a clipboard in the cab. This written information, e.g. as a TREMCARD, should contain details of the nature of the load and the action to take in an emergency.

Duties of vehicle operator
• Check whether the Road Traffic (Carriage of Dangerous Packages, etc.) Regulations 1986 apply. Exceptions apply to cylinders <5 litres; cylinders which are part of equipment carried on the vehicles, e.g. burning gear, bitumen boilers; cylinders associated with vehicle operation, e.g. cooking, water heating.
• Ensure the vehicle is suitable, normally an open vehicle. Use of a closed vehicle should be restricted to a small number of cylinders with a load compartment having adequate ventilation.
• Ensure the driver has adequate information in writing, e.g. a TREMCARD.
• Ensure the driver is provided with adequate instruction and training and keeps necessary records.
• Ensure loading, stowage, unloading are performed safely. All cylinders should be packed, strapped, supported in frames, or loaded to avoid damage resulting from relative movement. Cylinders should be stowed with valves uppermost.
• Ensure all precautions are taken to prevent fire or explosion.
• Ensure suitable fire extinguishers are provided.
• Ensure the vehicle displays two orange plates if 500 kg of LPG is carried.
• Report any fire, uncontrolled release or escape of the LPG, to the appropriate authority.

Duties of the driver
• Ensure the relevant written information from the operator is always available during carriage. Destroy, remove or lockaway information about previous loads.
• Ensure loading, stowage and unloading are performed safely.
• Ensure all precautions against fire or explosion are taken during carriage.
• Display orange plates (when required) and keep them clean and free from obstruction.
• If >3 tonnes of LPG is carried, when the vehicle is not being driven, ensure parking is in a safe place or that it is supervised (by the driver or a competent person aged >18).
• On request provide appropriate information to persons authorized to inspect the vehicle and load.
• Report any fire, uncontrolled release or escape of LPG, to the operator.

EMERGENCY PROCEDURES FOR DRIVERS IN TRANSPORTING RADIOACTIVE SUBSTANCE

Arrange for the police and emergency services to be alerted

Arrange for assistance to be given to any person injured or in immediate danger

If considered safe to do so – having regard to the nature of the emergency, the substance and the emergency equipment available – follow a selection of the following procedures in an appropriate order:

Stop the engine

Turn off any battery isolating switch

If there is no danger of ignition, operate the emergency flashing device

Move the vehicle to a location where any leakage would cause less harm

Wear appropriate protective clothing

Keep onlookers away

Place a red triangle warning device at the rear of the vehicle and near any spillage

Prevent smoking and direct other vehicles away from any fire risk area

Upon the police/fire brigade taking charge:

Show the written information, e.g. Tremcard, to them

Tell them of action taken and anything helpful about the load, etc.

At the end of the emergency, inform the operator.

The written information given to the driver should include:

The name of the substance

Its inherent dangers and appropriate safety measures

Action and treatment following contact/exposure

Action in the event of fire and fire-fighting equipment to be used

Action following spillage on the road

How and when to use any special safety equipment

HOW WAS THE EARTH FORMED? - BASIC INFORMATION ON THE FORMATION OF PLANET EARTH

The solar system formed about 4.6 billion years ago. The Earth and other terrestrial planets are believed to have formed by gathering together the so-called planetesimals.

Planetesimals are formed by the coalescence of fine- or coarse-grained mineral matters, metals, and gases of various kinds. As planetesimals stuck together mostly by gravity and the body thus formed grew larger, it became a precursor of terrestrial planet.

Some of these bodies were smashed by other bodies, and their fragments became meteorites. Hence, studies of meteorites would provide a lot of insight into the formation and the earlier state of the Earth.

The planet Earth was thus formed. Heat was created as the coalescence (of planetesimals) proceeded due to gravity, and heat also came from radioactivity of several radioactive elements such as aluminum-26. So the newly formed body was heated and the core was melted.

As the material becomes liquid (as a result of melting), the materials contained in the liquid separate out according to their densities. The more dense material would sink closer to the bottom (core).

Thus, the present layer structure of the Earth formed. The innermost core is a dense solid of about 1,200 km radius, whose density is about 12.6 g per cubic centimeter (12.6 ×106 kg/m3).

It is made of mostly iron metal and a small amount of nickel. By the way, the density of iron metal is only 7.8×106 kg/m3 under the ordinary pressure. The next layer is the outer core (up to 3,500 km from the center of the Earth), which is liquid and has a density of 9.5–12×106 kg/m3. The chemical composition seems to be about the same as that of the inner core.

There is an abrupt change in density in the next layer, mantle. The width of mantle is about 2,900 km (3,500–6,380 km from the center). Its density ranges from 4 to 5.5 ×106 kg/m3. The mantle is made of mostly magnesium–iron silicates (silicon oxides). The outermost layer is the thin crust of about 35–45 km on the land portion, and about 6 km under the ocean portion.

DNA REPLICATION - HOW IS DNA REPLICATED? BASIC INFORMATION AND TUTORIALS

Really. Just how dna is replicated?

This is quite clear at least in principle by now. It is based on the specific interaction between A and T, and between G and C. That is, take, for example, the double helix in figure below.

Let us label the left strand as “l” strand and the other “r” strand. (This is the complementary strand of “l”). Suppose that you separate the two strands and the “l” strand is isolated. Then you provide a pool of components A, C, G, and T and a means to bind nucleotides (enzyme called DNA polymerase) for the “l” strand.

This enzyme binds nucleotides one by one sequentially. The top bead A on the “l” strand binds a bead T (laterally through hydrogen bond), and next another bead on “l” binds laterally a bead T. Beads T and T are then connected through the phosphate group by the enzyme.

Next the bead G on “l” binds a bead C, and the bead C then is connected to the previous T on the right hand by the enzyme. This is repeated; then you see that an “l” strand will reproduce the complementary “r” strand. The reverse will also be true; i.e., an “r” strand will reproduce the corresponding “l” strand.

Thus, a double strand will have been replicated. How this is accomplished, i.e., mechanics of these chemical reactions are currently very intensely studied, is beyond the level of this book.

Hence, this topic will not be pursued further here. But, the very basic reason why we are like our parents or in other words why a gene molecule (DNA) is (almost) faithfully replicated and transmitted to a progeny can be understood as in the previous paragraph.

This replication mechanism of DNA, however, applies to only cell division. The issue of inheritance in sexual organisms like us is a little more complicated, because we get half of the gene from mother and the other half from father.

But again we are not able to elaborate on this issue here. The issue is more of biology (so-called genetics) than chemistry. The chemical principles are about the same.

We said, “DNA is (almost) faithfully replicated” in the paragraph above. The qualification “almost” implies that replication may not always be exact. In other words, a cell may make mistakes in replicating a DNA. It happens not very often, but frequently enough. If this happens, a wrong DNA may form, which would give
wrong information.

Mistakes can be caused by some factors (some cancer causing factors, for example) or without any particularly cause. The distinction between the right combination A–T/G–C and wrong combinations such as A–C/G–T is not quite definite.

Chemically speaking, the difference in interaction energy between the right and the wrong combination is not very great. Hence, there is some chance that the DNA-making mechanism may simply connect wrong nucleotides occasionally. This may be disastrous to the organism.

Therefore, many DNA-making mechanisms (DNA polymerases) contain in it three functions. One is polymerizing nucleotides (making DNA chain), of course.

The other two are monitoring and repairing mechanisms. It monitors what nucleotides are connected and can identify a wrong one. When it has recognized a wrong one, the repairing mechanism snips off the wrong one.

And then the polymerase portion reconnects another; this time a right one, hopefully. There are many other mechanisms known in organisms that repair “damaged” DNAs. All these are chemical reactions, but too complex to be talked about here. It is also to be noted that these occasional changes in DNA are the ultimate cause of change of species, i.e., evolution.