Intro4u2u

People who smoke may try to reduce the harm that smoking causes by cutting down or by smoking less damaging products

People who smoke may be unwilling or unable to stop smoking completely. Cutting down the number of cigarettes smoked daily or smoking less damaging products may reduce the harm caused by smoking. It may also be a step towards stopping smoking completely. This approach might, however, undermine the importance of quitting which has very clear health benefits. We found thirteen controlled trials that tested ways to help people to cut down the number of cigarettes they smoked. We did not find any randomized controlled trials which tested the effects of using products designed to reduce damage, such as Potentially Reduced Exposure tobacco Products (PREPs). Ten of the trials tested nicotine replacement therapy (NRT) as an aid to cutting down. Our combined analysis of eight of these trials (3273 smokers) found that nicotine replacement roughly doubled the odds of reducing the number of cigarettes per day by 50% or more. However, levels of carbon monoxide and cotinine (markers within the body of exposure to tobacco smoke) did not reduce by the same proportion. This suggested that there may not be a direct relationship between the reduction in number of cigarettes and the reduction in harmful effects. Although NRT helped significantly more people to cut down, few were able to sustain the reduction over time. NRT also nearly doubled the odds of quitting completely. One trial failed to find a benefit of bupropion either for cutting down or for quitting. Four trials tested advice or instructions for reducing the number of cigarettes smoked per day, and did not find clear evidence of a significant effect. We did not find any trials which reported the long-term effects on health of cutting down, and it remains uncertain how much health benefit there is from cutting down.

A pressure transmitter consists of several components including the sensor, signal-processing electronics, and signal-conditioning electronics. The sensor translates force from pressure acting on an area into an electrical signal–usually a millivoltage or voltage–that is amplified and converted by signal-processing circuitry The conditioning electronics convert the sensor output to a standard signal such as 4-20 mA, 0-10 VDC, etc.

The strain-gauge pressure transducer converts pressure (a force) to a resistance change proportional to the applied strain. The strain gauge circuit consists of one, two, or four variable-precision resistors in a Wheatstone-bridge configuration. When the resistors are subjected to pressure they deform, changing the resistance of the circuit. A strain gauge sends a millivolt output signal.

Some advantages of the strain-gauge sensor are that it is widely available from many vendors and has good immunity to shock and vibration. Principle limitations include sensitivity to swings in temperature (more sophisticated designs have temperature compensation) and limited temperature and pressure ranges.

The output of a capacitive sensor is proportional to the change in capacitance of two diaphragms (plates) inside the transducer. Applied pressure changes the distance between the two plates, causing a change in the capacitance that is detected by an oscillator circuit. Analog transmitters convert the frequency to a voltage, while digital transmitters work directly from the sampled frequency.

The principal limitation of capacitive sensors is that they are somewhat sensitive to vibration. They provide excellent response and stability, and are widely applied in many pressure transmitter manufacturers’ designs. This large installed base allows the instrument engineer to draw on a great deal of installation experience when choosing this type of transducer.

In a quartz resonator sensor, pressure results in a change in frequency across the resonator that is directly proportional to the applied force. These transducers can be scaled over a wide range of pressures, and typically contain a quartz-crystal temperature sensor for temperature compensation. This type of sensor can offer increased immunity to temperature, vibration, and acceleration.

The vibrating wire and cylinder sensor has a wire excited by a magnetic coil. The wire vibrates at its resonant frequency in a phased locked loop (PLL) electrical circuit. A pressure-sensing diaphragm changes the tension in the vibrating wire, causing a change in resonant frequency proportional to the applied pressure.

Sidebar 2:

Smart Pressure Transmitters

Smart pressure transmitters differ from their analog counterparts in their ability to offer enhanced capabilities. Functionally, the smart pressure transmitter provides additional features such as improved accuracy, reduced commissioning cost, and lower life cycle costs.

Smart pressure transmitters typically offer much larger turndown ratios than traditional analog transmitters. This means the same transmitter can serve several different applications, decreasing the numbers and types of spare transmitters in maintenance inventories.

Reduced drift can allow increased calibration intervals ,one source advocates a minimum of two years between calibration checks,and some smart transmitters can be re-ranged during operation.

Other features can give increased flexibility in developing control strategies. These include advanced computations (such as gas mass flow rate) using multiple variables (such as temperature via an RTD input and differential pressure), digital output in engineering units, calculation of compensated values, and improved ability to compensate for influence errors and non-linearities.

Taking advantage of digital connectivity can depend on using the same manufacturer’s transmitters and the same handheld communicator,for example, while many manufacturers use the HART protocol, one manufacturer’s handheld terminal may not access all the digital data produced by a different manufacturer’s transmitter.

Smart transmitters offer diagnostic capabilities from traditional 4-20 mA loops via the HART communications protocol, re-ranging the transmitter from the control room, the transmitter tag name, firmware identification information, internal parameters, statuses, and set-up parameters. The user can also suppress or elevate span or zero on the instrument as required. Some manufacturers offer data such as the last time the instrument was calibrated or on-board diagnostics that determine when the instrument requires calibration.

Sidebar 3:

Pressure Primer

Pressure is defined as force per unit area. Pressure measurements can be further divided into relative, absolute, or vacuum pressures. A relative pressure is known as a gauge pressure measurement when referenced to barometric pressure, differential when referenced to another pressure, and can have a reference point that shifts. An absolute pressure measurement is referenced to a perfect vacuum (a point of zero pressure).

Absolute pressure measurements are related to a fixed reference that remains unchanged regardless of temperature, location, or other ambient condition. Gauge pressure transducers are referenced to barometric pressure through a low-side port that is open to the atmosphere.

To convert between absolute and gauge pressure, use the equation:

Gauge pressure + Barometric pressure = Absolute pressure

Differential pressure transmitters measure the difference in pressure between two transmitter connections, and can be used to measure both level and flow. Level measurements can be made on either open or closed tanks. The general principle is expressed by the equation:

P = h x conversion x SG

where h is the height of the fluid expressed in inches of water column (in. WC) and SG is the specific gravity. Level transmitters are generally calibrated in inches of water, and the output is 0-100% related to “h” in inches or more commonly feet.

In an open tank, the pressure instrument measures gauge pressure because the liquid inside the tank is exposed atmospheric pressure, which is the same as the reference pressure for the transmitter.

On a closed tank, a differential pressure transmitter is used and effectively subtracts the pressure on the top of the liquid from the pressure at the bottom of the tank to measure only the liquid head pressure. Be wary of closed tanks operating at atmospheric conditions,there may be a small pressure pad, conservation vent operations, or head pressure variations that will affect a level transmitter that does not have its low side connected to the head space.

Differential pressure transmitters are also commonly used in flow measurement. As the volume of a fluid flowing through a closed conduit (a pipe) is forced through a restriction such as a Venturi or orifice, the velocity of the fluid increases. The resulting increase in velocity causes a change in kinetic energy that causes a decrease in static pressure (potential energy). The flow is proportional to the square root of the differential pressure across the restriction.

Pressure transmitters are widely applied for a variety of measurement purposes, and they cause a lot of trouble. Zeros shift, lines plug, and readings become erratic.

But fundamentally, there’s no reason to have pressure measurement problems. All over the world there are transmitter installations giving consistent, accurate pressure readings in the most difficult applications. The key is to specify and install pressure transmitters wisely.

The heart (and in many cases, the limitation) of a pressure transmitter is the transducer (an overview is in the sidebar, Transducer Technologies, and a more complete treatment can be found in Reference 1). The critical factors used to select a transducer are its accuracy, the system pressure and temperature, and fluid characteristics.

Examine Accuracy

Controls experts such as Bala Liptok have said inaccuracy is probably a better measure of instrument performance. Engineers must recognize that many accuracy statements may be formulated based on laboratory-like conditions that are much more benign than the dirty and electrically noisy environment seen by a pressure transmitter inside a plant.

The engineer should ask the transmitter manufacturer two questions:

1. Is every transmitter tested to meet the accuracy specification?

2. If only a representative sample of transmitters is tested, what statistical method was used to develop the statement? Statistical criteria include the size of the population, statistical limits of error, and confidence.

Ask about effects of factors such as humidity and vibration on hysteresis, linearity, drift, and repeatability (Table I). Each pressure transmitter has an accuracy envelope determined by base accuracy, ambient and process exposure, and drift.

It is common for manufacturers to combine linearity, hysteresis, and repeatability into the base or nominal accuracy. The primary contributors to error are temperature and, in the case of differential pressure measurements, static pressure.

Determine Pressure and Temperature Ranges

Examine the pressure application and determine the maximum pressure that the transmitter will see.

Consider the following values:

1. The normal operating pressure range, low and high.

2. The maximum abnormal operating pressure range, low and high.

3. The maximum safe overpressure range (burst or damage limits).

4. Peak and frequency of pressure pulses.

The low limit of pressure must be considered if the transmitter can be damaged by vacuum and could be exposed to vacuum. Users should also pay attention to the hydrotest pressure associated with the line, though this does not tend to be a problem. Also, if the sensor is directly exposed to high temperature, the pressure rating will be limited by that temperature. Exposure to abnormal events (such as water hammer) must also be taken into account.

Once the pressure limits are determined, it is good practice to allow a 20% safety factor. If there is an overpressure or safety device, the pressure rating of the transmitter can be at the trip setting of the overpressure device.

Over-rating a transmitter can negatively impact its range and sensitivity. These two parameters have a direct correlation to the accuracy of the measurement. The installation of a pressure snubber or dampener could alleviate the need for the safety factor, as we’ll discuss later.

Select a transmitter with the operating pressures at 50-75% of the calibrated range. This assumes that there are not many expected upsets that could cause large swings in pressure. If there are large swings (widening the range) due to process conditions, installing a second transmitter to handle the additional range should be considered.

Consider both the process temperature range and the ambient temperature range. The process temperature range represents the normal and abnormal temperatures the transducer will be exposed to via the process. The ambient temperature range gives the amount of temperature error to allow for without degrading performance outside the limits set by the application.

Install Properly

Accurate, reliable pressure measurements depend on correct installation. Start with location: A transmitter with a small display 50 ft. in the air next to a ladder becomes an operability issue. If maintenance personnel can’t reach the transmitter, there is a maintainability, and possibly a safety, issue.

The manufacturer’s installation literature describes how much vertical and horizontal distance is required around the transmitter to ensure it can be placed in and out of service easily.

Determine if and how the instrument will be taken out of service for maintenance and calibration without shutting down the process or injuring personnel with leaks or spills. A root valve and secondary block valve can isolate the instrument from the process. Some manufacturers will furnish this item as part of the transmitter assembly, or a manifold can be furnished as a separate item.

To keep maintenance costs down, look for a transmitter with modular components. For example, modularity would allow one piece of electronic circuitry inside the transmitter to be replaced in lieu of replacing the entire transmitter.

Impulse lines connecting the process to the transmitter should be kept as short as possible. One manufacturer estimates that impulse lines represent more than half the problems associated with instrument performance.
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Instruments used in a liquid or condensable vapor should be mounted below the process connection. Impulse lines should be sloped down toward the instrument to prevent trapped gases inside the instrument or impulse lines. Transmitters should be bought with ports to allow venting of gas or draining as appropriate. Vertical lines are also generally sloped slightly to minimize the chance of vapor lock.

Instruments used in gas pressure measurement should be mounted above the process connection. Impulse lines should be sloped away from the instrument to prevent trapping liquids inside the instrument.

Route signal wiring away from power conductors per the spacing requirements listed in IEEE 518, Guide for the Installation of Electrical Equipment to Minimize Electrical Noise Inputs to Controllers From External Sources. Ensure that the signal shield is grounded only at one end and that conduit systems have intentional low points equipped with breather/drain assemblies for removing moisture.

Consider using block and bleed valves. The block and bleed valve has two purposes: for removing the instrument from the line without leakage, and for zeroing and testing the instrument. A bypass valve must be added if the measurement is differential pressure.

Dampeners, Seals, and Purging

Be aware of what types of transients could occur in the line where the transmitter is mounted. This is particularly important if a pressure transmitter is installed near a pump discharge. Pulsation dampeners are generally used to damp out process fluid pulsations, more often for signal fluctuations but possibly for protection against mechanical vibrations that might damage the transmitter.

One dampening technique is installing a pigtail in the impulse piping between the instrument and the process root valve connection, and some transmitters are available with built-in dampening. Signal pulsations are generally filtered by a dampener rather than time-delayed, so the output is an average of the pulsations. This raises the question of whether the transmitter will provide a representative signal.

Chemical seals serve several purposes in a transmitter installation:

* Preventing contact of potential noxious or corrosive process fluid with the transmitter.

* In certain cases, serving as a winterizing function in lieu of the electrical or steam tracing devices.

* Allowing remote mounting of a transmitter for better maintenance access (using a diaphragm and capillary-type seal). This can also alleviate some of the burdens associated with area classification if the diaphragm and capillary seal allows the instrument to be mounted outside the hazardous area. It is considered good practice to allow no more than 25 ft. of capillary tubing from the diaphragm to the transmitter. A downside to a capillary can be additional loop deadtime.

* Preventing solids or slurries from plugging the measurement element.

* Providing a larger surface area or process connection, which can improve sensitivity and help minimize plugging.

It is critical that the liquid in the seal be capable of withstanding the temperature at the process connection and the ambient temperature without freezing or gelling. The fluid should also be compatible with the process fluid so there is no major contamination problem should the seal break. Work with the transmitter or seal manufacturer to select the correct fluid.

Pay attention to the construction of the seal, and in general, look for fully-welded seals. In sanitary services, consider an approved self-cleaning seal. If vacuum is present, use a seal designed and constructed for that kind of service.

Purging is used to keep the instrument clear of process fluid that can cause plugging of the impulse lines or the transmitter. Purging is commonly used in applications involving solids, process fluids that are subject to solidification or plugging, and acid or basic fluids. The purge fluid must be compatible with the process and delivered at a higher pressure than the process, with check valves for backflow prevention. Reference 7 includes information on determining purge flow rates.

Before selecting the sensor type, if the specifier understands the measured process fluid and its characteristics in various temperatures and pressures, knows the conditions the transmitter will experience, and provides adequate room to install and maintain the transmitter, there’s an excellent chance the proper pressure measurement technology will be applied

6. Process Measurement Instrumentation, American Petroleum Institute Recommended Practice 551, Washington, D.C.

7. Manual on Installation of Refinery Instruments and Control Systems, American Petroleum Institute Recommended Practice 550, Part I, Section 4: Pressure (out of print).

8. Manual on Installation of Refinery Instruments and Control Systems, American Petroleum Institute Recommended Practice 550, Part I, Section 8: Purges, Seals, and Winterizing (out of print).

9. “How Accurate Is Accurate?” Bill Mostia, CONTROL Magazine, June, July, and August, 1998.

Ever hear the old adage “Locate static pressure transmitter 2/3 down the length of the main trunkline.”? Or how about “Install differential pressure transmitter at the end of the furthest run.”? These seemingly arbitrary little “rules of thumb” are written over and over again, in specs, on control drawings, in sequences of operation, etc. But where did they come from, and what exactly are the governing principles behind them? In this article we’ll explore those issues, and hopefully answer those questions. But first, a little background on just exactly what we’re talking about here.

On the airside, static pressure transmitters are implemented in VAV air handling systems, those that operate to maintain a constant supply duct static pressure. As VAV boxes connected to the main trunkline open and close, the static pressure in the trunk has a tendency to vary. The trunk is kept pressurized by the supply fan’s variable frequency drive (VFD), which has the means to slow down and speed up the supply fan as required to maintain pressure. The pressure transmitter in this case measures duct pressure with respect to the pressure outside of the duct. The pressure signal is transmitted to the air handler’s main controller, and processed against pressure setpoint. The resulting signal is fed to the variable frequency drive, which in turn varies the speed of the fan to precisely and continuously maintain duct static pressure setpoint (we hope!).

On the waterside, differential pressure transmitters are utilized in variable flow pumping systems, whereby the pump speed is controlled (via VFD) to maintain a suitable differential pressure across the supply and return mains. Unitary equipment fitted with two-way control valves connect to the mains (hot and/or chilled water); the control valves modulate as a function of their individual unitary temperature control process. As this occurs, the pressure in the mains tends to fluctuate. A differential pressure transmitter installed across the supply and return mains monitors the pressure, and transmits it back to the pumping system’s main controller. The pressure signal is compared with the operating setpoint, and the calculation results in a control signal that feeds the pump’s variable frequency drive. The VFD in response varies the pump speed in order to achieve and consistently maintain differential pressure setpoint.

Properly sizing a pressure transmitter for an application shouldn’t be an arduous task. We’re not re-inventing the wheel here, and there’s plenty of practical and theoretical data to call upon when faced with the undertaking of selecting the appropriate range for the given application. Manufacturers typically offer a family of transmitters with differing ranges, so that makes things a little tricky right form the get-go. You may ask why these manufacturers just don’t make a single, range selectable or auto-ranging device, a “one size fits all”, so to speak. Well, I’m sure they’re all working on it, but until that time comes, we’re forced to choose from their offering, and hope that our selection fits the application.

For the airside application, the selection is actually pretty straightforward. There is a widely acknowledged rule of thumb calling for the “design” supply air static pressure setpoint to be in the area of 1.5” W.C. (inches of water column), or more commonly heard as “an inch and a half of static”. So select a pressure transmitter with a range greater than this. The trick is to be conservative with your selection, allowing for pressures greater than the “design” setpoint, but not so conservative that your selection ends up being the highest range that the manufacturer offers. Why not? Well, it has to do with signal resolution and precision. Just as you wouldn’t want to use a yardstick to measure the thickness of a penny, you don’t want to use a large ranged pressure monitoring device to measure a pressure whose practical range falls within a fraction of the device. Better to “rightsize” the device rather than oversize it. Your commissioning crew will appreciate it, at the very least.

ONICON Incorporated For the waterside application, the selection of the pressure transmitter requires a little more insight. The “system setpoint” is generally not given in these applications, and is something that is typically determined after the system is installed, upon balancing the system. But the transmitter needs to be purchased and installed long before the balancer hits the jobsite. For a typical small to mid-sized HVAC piping system, required system design pressure is generally in the range of 10 to 20 PSI. That’s a starting point. A good practice is to select the pressure transmitter in accordance with the pumps selected for the system. For instance, if the pumps are selected to provide 40 “feet of head”, this value can be divided by 2.31 (PSI = ft. hd. / 2.31), yielding a result of 17.3 PSI. A controller with a 0 to 20 PSI range will suffice for the application. Location will play a part in selecting the range as well. If you’re locating the transmitter right there at the discharge of the pumps, then you would size for system design pressure. If you’re required to locate the device further downstream in the system (more on that in a minute), then you may be able to get away with the next smallest available range. Again, a transmitter with an oversized range will tend to not have the accuracy or the resolution that a “right-sized” transmitter will, so be careful with your selection, and put some thought into it instead of arbitrarily selecting a controller sized for total system pressure.

Placement rules for pressure transmitters are backed by a combination of both theoretical data and traditionally accepted practices. In the end, your choice for locating the transmitter will prove whether or not you’ve made the right decision. Not to worry. There’s no magic here. Just some things to know and some guidelines to follow.

For the airside, static pressure placement depends on the geometry of the duct system. For systems that have straight duct runouts, the static pressure transmitter should be installed in the main trunk, at least two-thirds of the way down the line, if not further. This assures that the most remote VAV boxes on the system get the pressure that they need, when the system is maintained at setpoint. For looped duct systems, placement of the transmitter is more arbitrary, assuming that the static pressure within the loop is relatively uniform and consistent throughout the loop. Put some distance between the transmitter and the discharge of the supply fan, get it in a straight section of duct away from elbows and transitions, and you should be good to go. For larger systems (both looped and unlooped), multiple transmitters may be required whose locations can be chosen by reviewing the mechanical plans and determining proper sensing points. The signals of these transmitters can be averaged, and the main controller can perform an averaging calculation in order to determine the proper course of action on the supply fan.
Tip of the Month: When actually physically installing pressure transmitters, if at all permissible, strike a balance between specified or “theoretically correct” placement, and practicality.

For the waterside, theory dictates that the differential pressure transmitter should be located at the end of the furthest piping run. This ensures both optimum energy savings and adequate flow for all loads in such a system. By way of example, consider that, in order to guarantee design flow at the “extremity” (furthermost load in the piping system), the differential pressure at that point in the system needs to be maintained at 5 PSI. Now consider under worst case conditions (all loads in the system calling for, and incurring, full design flow), the differential pressure right off the discharge of the system pump is found to be 10 PSI. Reasoning would have it that, if we maintained 10 PSI at the discharge of the pump, then we should be able to satisfy all loads on the system under all conditions. This is true, and therefore we can install the differential pressure transmitter right there, establish the setpoint as 10 PSI, and be done with it. However it is also true that, as loads are satisfied and flow is reduced, there is less friction in the pipes to overcome. Thus under part-load conditions (some loads calling and others satisfied), to guarantee 5 PSI (and hence design flow) at the extremity, a differential pressure of somewhat less than 10 PSI is all that is needed at the discharge of the system pump. By locating the differential pressure transmitter at the pump discharge and setting the setpoint at 10 PSI, for virtually any operating condition other than worst case, the system is using excess energy and potential savings opportunities are lost. On the other hand, by locating the differential pressure transmitter at the extremity, we can directly control to the needs of the extremity. Assuming that if we control to the needs of the extremity, all prior loads on the system will be guaranteed their design flow rates, then the system is optimized, that is, from an energy usage standpoint

Dr Salman Shah, Advisor to the Prime Minister on Finance and Revenue on Friday hinted towards an increase in petroleum prices in near future and said that if the current trend in oil prices continues than there would be pressure on us by year-end.

He was responding to a question regarding the historic rise in oil prices in the international market where the commodity is being traded at $82 per barrel against its previous highest price of $65 per barrel in the international market.

After presiding over the 3rd meeting of the Task Force on Public Private Partnerships at Ministry of Finance, the Advisor said that the current level of oil prices is dangerous for global economy as well as for Pakistan and hoped that the current level which he termed as historic would come down.

“Pakistan’s economy is able to absorb the current oil price shock at present but definitely it would have its implications on our economy. We would review the situation in next two to three weeks and would examine its impact on overall economy and budget”, he added.

Dr Shah said that at present the government is able to continue maintaining and subsidising the existing the petroleum prices due to budget allocations for this purpose. If the current trend continues than we would be looking at slashing the Petroleum Development Surcharge (PDS) or Petroleum Development Levy (PDL) to absorb the shock in near future. However, if the oil prices continue to be at the existing level or even more higher than there would be pressure on us to review the situation by the year-end, he maintained.

The federal government in the budget for current fiscal year 2007-08 has allocated Rs 15 billion to subsidise the petroleum products’ prices and to save the public from adverse impact of high oil prices. However, it would not be easy for the government to continue to subsidise the petroleum products’ prices beyond two to three months if current oil prices continue in the time to come.

Experts are of the opinion that the government would not increase petroleum products’ prices despite the increase in oil prices in the international market due to political gains it is aiming at during presidential elections scheduled for October 6, 2007 and general elections to be held later during the year or during the first quarter of the next calendar year. But the government would not be in a position to continue subsidising the prices of petroleum products for the full fiscal year; otherwise, it would increase the budget deficit.

According to foreign media reports, oil prices were hovering around $82 a barrel on Thursday as sinking US crude inventories and the threat of a storm gathering near Florida increased worries of a winter supply crunch in the world’s top consumer. Oil has traded above $80 for the past week but OPEC officials and oil analysts say the current high price is unsustainable. US light crude edged up 35 cents to $82.27 a barrel after a record-high of $82.51 on Wednesday, the sixth straight session to hit a record. London Brent crude fell 33 cents to $78.14.

Oil has risen by a third this year; driven by worries of fuel shortages during the Northern Hemisphere winter, supply risks in countries ranging from Mexico to Iran and flows of money into oil and out of poorly performing equity markets.

While global oil prices climbed record high this week pushing the benchmark Indian basket to the year’s high of $76.13 a barrel, the troubled UPA coalition at the Centre abandoned thoughts of raising fuel prices and withdrawing the subsidy on cooking gas for the non-poor.

The Indian basket comprises Oman-Dubai sour grade and Brent dated sweet crude in a 60:40 ratio.

It is the government-owned oil companies that will bear the brunt of Rs 5.75 a litre loss on sale of diesel, Rs 3.35 on petrol and Rs 15.47 on kerosene and Rs 174.75 on every cylinder of LPG.

The petroleum ministry had earlier this month, through a status report meant for the Prime Minister and Cabinet, drawn the government’s attention to domestic oil marketing companies losing heavily because of the growing mismatch between global and domestic fuel prices. However, petroleum minister Murli Deora has ruled out any hike in domestic fuel prices.

A senior government functionary said the government is struggling with the difficult task of political management over the Indo-US nuclear deal and the Ram Setu row.

“It has little political capital to expend on taking the hard and potentially unpopular decisions of increasing fuel prices.”

More than the price hike, it is the lack of political will to issue oil bonds to the companies for compensating losses is what is disturbing their investment plans.

“Normally, the administrative ministry pushes the case of petroleum companies for a hike when it sees they are going in red but the response of petroleum ministry is timid though it is well known now that oil marketing companies Indian Oil Corporation, Hindustan Petroleum and Bharat Petroleum may close the second quarter with losses,” said a senior official.

Government sources said the petroleum ministry has been told that hike in consumer prices of petroleum products is not a viable option in the current political situation facing the government but at the same time no alternative mechanism has been worked out.

Parliament’s monsoon session ended without the government getting approval for oil bonds to compensate for around Rs 50,400 crore annualised losses.

“Fuel price hike is a difficult political task at most times. It is more so now,” said a minister engaged with the current trouble-shooting efforts with the government’s Left allies on the nuclear issue.

Decisions such as hiking the prices of petrol and diesel and cutting subsidies on cooking gas would require consultations with not only the Left parties, which are bound to see red, but also within the UPA coalition. UPA constituents including RJD and DMK are not in favour of any increase in fuel prices now.

“With inflation staying below 4 per cent for the latest four weeks, there was perhaps a window of opportunity to pass on to the consumer a little bit of the burden of the global oil price increase,” said a finance ministry official, “but clearly the government is politically not in a position to bite the bullet. It has no appetite for opening another front (of confrontation within the ruling coalition),” he said.

How Coriolis Mass Flowmeters Work
Coriolis mass flowmeters measure the force resulting from the acceleration caused by mass moving toward (or away from) a center of rotation. This effect can be experienced when riding a merry-go-round, where moving toward the center will cause a person to have to “lean into” the rotation so as to maintain balance. As related to flowmeters, the effect can be demonstrated by flowing water in a loop of flexible hose that is “swung” back and forth in front of the body with both hands. Because the water is flowing toward and away from the hands, opposite forces are generated and cause the hose to twist.
In a Coriolis mass flowmeter, the “swinging” is generated by vibrating the tube(s) in which the fluid flows. The amount of twist is proportional to the mass flow rate of fluid passing through the tube(s). Sensors and a Coriolis mass flowmeter transmitter are used to measure the twist and generate a linear flow signal.
How to Use Coriolis Mass Flowmeters
Coriolis mass flowmeters measure the mass flow of liquids, such as water, acids, caustic, chemicals, and gases/vapors. Because mass flow is measured, the measurement is not affected by fluid density changes. Be particularly careful when using Coriolis mass flowmeters to measure gas/vapor flows because flow rates tend to be low in the flow range (where accuracy is degraded). Also, in gas/vapor applications, large pressure drops across the flowmeter and its associated piping can occur.
This flowmeter can be applied to sanitary, cryogenic, relatively clean, and corrosive liquids and gases/vapors in pipes smaller than 6-12 inches. General applications are found in the water, wastewater, mining, mineral processing, power, pulp and paper, petroleum, chemical, and petrochemical industries. Materials of construction are generally limited to stainless steel and Hastelloy C. Straight-tube designs are available to measure some dirty and/or abrasive liquids.
Many applications for Coriolis mass flowmeters are found in chemical processes where fluids can be corrosive and otherwise difficult to measure. In addition, the relative insensitivity to density allows Coriolis mass flowmeters to be applied in applications where the physical properties of the fluid are not well known. These flowmeters can also be used in chemical feed systems found in most industries.
Application Cautions for Coriolis Mass Flowmeters
If the pressure drop is acceptable, operate a Coriolis mass flowmeter in the upper part of its flow range because operation at low flow rates can degrade accuracy. Note that high viscosity fluids increase the pressure drop across the flowmeter. For liquid flows, make sure that the flowmeter is completely full of liquid. Be especially careful when measuring gas/vapor flow with Coriolis mass flowmeters. Pay special attention to installation because pipe vibration can cause operational problems.

Bioremediation is the natural process of degrading organic materials to carbon dioxide, water and various ions. It is literally as old as life on earth. Microbes that exist naturally in all soil and water produce enzymes which breakdown hydrocarbons into smaller, less toxic materials.

Using modern biotechnology we have found ways to accelerate and improve the effectiveness of bioremediation. Naturally occurring microbes have been selectively adapted for their ability to digest specific hydrocarbon contaminants such as oil and gasoline. The Microbes are combined with nutrients, pH stabilizers, oxygen and surfactants. The result is a product which when applied to contaminated soil or water, optimizes the environment for bioremediation to take place. The remediation process is accelerated dramatically. The contamination is mineralized and the environmental hazard is reduced or eliminated.

In many cases, petroleum encountered in a site investigation has been chemically altered due to environmental exposure, and its property change - sometimes radically - resulting in a gas chromatographic trace with little resemblance to the unaltered product. To the untrained eye, these altered GC traces can be misinterpreted, leading to the wrong conclusions about source, transport and fate of petroleum in the study area.

Occasionally, samples collected from a site contain petroleum products or related wastes that have remained chemically intact since the time of release. Using well-established laboratory and gas chromatographic techniques, a laboratory analyst with reasonable experience can usually identify the petroleum present in such samples.

The three most commonly encountered weathering pathways that affect fugitive petroleum are microbial degradation, evaporation and solubilization.

Microbial degradation. There are indigenous microbial populations in most environmental media capable of degrading petroleum given favorable conditions such as availability of oxygen, water, and nutrients. Although almost all of the major chemical classes of petroleum are biodegradable, the normal alkanes are most susceptible to this weathering pathway, and are usually the first compounds to show evidence of degradation following a release.

Evaporation. Selective losses of low molecular weight compounds - molecular weight of about 150 a.m.u. and less due to evaporation can be a significant part of the weathering process. Obviously, the lighter the spilled product is gasoline as opposed to crude, for example, the more likely that evaporative losses will constitute a significant portion of the overall weathering.

Solubilization. Most hydrocarbons that make up petroleum have low solubility in water, however certain compounds, notably the lower molecular weight aromatics and some low molecular weight aliphatics -have reasonable was solubility. For example, the monoaromatic compounds, principally benzene, ethylbenzene, toluene and the xylenes (BTEX), lesser alkylated benzenes (< C4), and naphthalene and its C1- analogues have notable solubilities, such as solubility of benzene at 1780 mg/L to 2-methylnaphthalene - 25 mg/L.

Armed with such knowledge, the site investigator can confidently identify and track fugitive petroleum at a study site. If faced with a weathered product that must be distinguished from other petroleum sources of like or different composition, it also allows the investigator to tailor further, more sophisticated chemical analyses and interpret those results in light of the weathering state of the in-place petroleum.

1.1    Chemical Used for Bioremediation

Surfactant can enhance bioremediation performance. Surfactants can act in two ways which are increase solubility and lower the interfacial tension by reducing the capillary forces.

(a)    BioSurfactant - BioSolve

BioSolve  is water based and biodegradable that will accelerate the bioremediation by:

i)    Increasing the speed of carbon substrate exposure to the microorganisms and the dispersion of the micro-organism’s’ enzymes
ii)    Desorbing and dispersing the contaminate into a more acceptable environment for micro-organisms ( aqueous phase)
iii)    Encapsulating VOC’s into the water to prevent volatilisation

(b)    Micro Nutrient - Desludge

Micro nutrient is an environmentally, bio degradable, non-toxic, non-hazardous product. It designed to be used with naturally occurring bacteria or with an enhanced bacteria package. It can keep the bacteria aerobic for longer time. Will consume more contaminated oil and faster. Does not contain enzymes, formaldehyde or chlorine; is not a biocide as well as practical and economical.

1.2 Application of BioSolve

l    Soil remediation
-    Enhance the microbe’s ability to metabolize the contaminated
l    Vapor Suppression
-  Encapsulates the source of the vapor rather than temporarily blanketing it like foam
l    Bioremediation
-    Produced excellent results when used in conjunction with nutrients
-    Shorter time frame and greatly reduced overall costs to remediate
l    Water Treatment
-    Proven effective in accelerating the degradation levels within legal discharge limits.
l    In Storage Tank
-    Proven effective in eliminating or reducing VOC vapors
l    Spill Clean –Up
-    Emulsifies and encapsulates the contaminants almost instantly
-    Helping to eliminate the danger
l    In Sewers
-    Successfully utilized by Emergency Response Teams in numerous instances of volatile hydrocarbon discharges into sewer systems.
-    Immediately helps reduce or eliminate the vapor release and the danger of fire or explosion.

1.3    Some others chemical groups that Biosurfactant can be used (other than
Hydrocarbon)
1.    Glycol Ether                    7.    Alcohols
2.    Glycol Ether Acetates (*)            8.    Aliphatic Solvents
3.    Jeffamine Ployoxypropleneamines(*)    9.    Aromatic Solvents
4.    Jeffcool Industrial Coolants (*)        10.    Esters
5.    Jeffox Polyethylene Glycols (*)        11.    Glycols
6.    Keytones
Note:    (*)    Commercial named group

1.4    Uses of BioSolve

Biosurfactant has a wide range of users and uses such as Environmental Clean-Up Companies, Petroleum Tank Farms, Oil Refineries, Fire Department Hazmat Teams, Water Treatments Facilities, Manufacturers, Utility Companies, Airports, Military Shipyards, Marinas, Drilling Platform and many more.

Solve can enhance the microbe’s ability to metabolise the contaminate by stripping the hydrocarbon off the soil particles and emulsifying it into the pore space
Hydrocarbon that has been stripped off from soil particles

BioSolve encapsulates the contaminate in water so that it can’t vaporize and to allow bacteria quickly metabolise the contaminate

Microorganisms digest hydrocarbon and convert it to carbon dioxide and water
Oil
Microbe
CO2 + H2O
CO2 + H2O
Microorganisms eat hydrocarbon or other organic contaminant
Microorganisms give off carbon dioxide and water

1.5    BioSolve Overview

BioSolve is a unique blend of biodegradable, water based surfactants, wetting agents and emulsifier developed after years formulation. Our team was developed for, and has been utilized by the environmental clean up for over 5 years as an effective solution to enhancing many technologies for contaminant mitigation. These technology include bioremediation, VOC vapor & odor suppression, tank entry, workover turnarounds, UST washouts, emergency response, spill mitigation, soil washing and sludge separation.

BioSolve can be stored for long-term storage, which is more than 10 years with no deterioration of quality in unopened container. It is effective with hard, soft, brackish or salt waters and also not affected by freezing, simply thaw and stir.

BioSolve is the result of tests on hundreds of formulations. It is a uniquely balanced blend of water based nonionic with a slight amount of anionic surfactant. BioSolve  does not contain cationic surfactants nor does it contain phosphates, nitrates or D-Limonene.

So far there is no one record highlighted the side effect of using our biosolve to the system treated and environment.

Asthma
An asthma attack is when something (such as dust, pollen, cigarette smoke) triggers a switch
in the person that causes their air passages to constrict, tighten, and spasm
causing the person to cough, wheeze and have difficulty breathing. They can also
be caused by anxiety and tension. Most people who suffer attacks on a rather
regular basis will carry their medication with them.
If someone you are with is having an attack:
l Help them assume an upright position, it will be for them to breathe than
if they were lying down. You may want to encourage the person to sit with
their legs crossed and their elbows on their knees as this is a relaxing position and may ease
breathing.
l Talk to the person calmly and try to help them to relax.
l Make sure they are in an area where there is a good supply of clean air (as
opposed to a dusty room).
l As soon as the person is sitting down, have them take their medication. If
they cannot then you will have to assist them. Shake the
puffer and give them one puff of reliever (with or without a spacer), they
should then hold that breath for 4 seconds then breathe in and out
normally 4 times. Repeat this step four times.
l Wait 4 or so minutes. If there is no improvement repeat the previous step
again.
l If there is still no improvement call an ambulance and continue repeating the process until help
arrives.
Hyperventilation
Hyperventilation is rapid short breathing, and the symptoms usually last 15 minutes to half an
hour, although to the person experiencing them it will seem much longer. It may be frightening but
hyperventilation is usually harmless and can be triggered by things such as:
Anxiety (most commonly)
Extensive physical injuries
Severe stomach pains
Heart or lung disease
If you are hyperventilating:
l Loosely cover your nose and mouth with a small paper bag.
l Slowly breathe into the bag and re-breathe the air in the bag about 10 times.
l Put the bag down and breathe normally for a few minutes before picking up the bag and
repeating the previous step again.
l Repeat these steps until the symptoms lessen or go away.
l Try to focus on your breathing and remain clam. Try to take one breath every 5 seconds.
If someone you are with is hyperventilating:
l Stay calm and speak to the person clearly and slowly, if possible make eye contact.
l Don’t crowd the person, give them space and make calming gestures and try to avoid- Breathing Problems
making a scene. If they are not already sitting, have the person sit down.
l Encourage them to breathe normally, and walk them through the breathing cycle
“breathe…slowly…hold…release…slowly…rest…breathe…” and do the cycle with them.
You’ll want to pause for 1-2 seconds while holding the breath, and before inhaling again.
l If they are doing it right, calmly encourage them to keep going while continuing to breathe
evenly and slowly.
Panic Attacks:
Panic attacks are brought on by social situation and activities that are perceived as a threat to
the person experiencing them. They can happen to anyone, and are usually not a serious threat. They
can however occur rapidly and repeatedly, and even after the attack the person may be highly anxious
for many hours afterwards.
Symptoms (not all will be present at once):
l Shortness of breath with rapid breathing, or hyperventilation
l Palpitations or accelerated heart rate (when you can ‘feel your heart pounding’)
l Trembling or shaking
l Choking
l Chills, or flushing
l Sweating
l Nausea
l Numbness, or pins and needles in the arms and legs
l Chest pain or discomfort in the chest region (if pains persist after attack see a doctor, it may be
signs of a heart attack)
l Fear of dying
l Fear of going crazy or doing something crazy
You treat a panic attack the same way you would treat someone who is hyperventilating.
l Stay calm and speak to the person clearly and slowly, if possible make eye contact.
l Don’t crowd the person, give them space and make calming gestures and try to avoid
making a scene. If they are not already sitting, have the person sit down.
l Encourage them to breathe normally, and walk them through the breathing cycle
“breathe…slowly…hold…release…slowly…rest…breathe…” and do the cycle with them.
You’ll want to pause for 1-2 seconds while holding the breath, and before inhaling again.
l If they are doing it right, calmly encourage them to keep going while continuing to breathe
evenly and slowly.

Classification Of Bites

Bites of all kinds are serious, as bacteria and diseases are released directly into the body, and
can spread quickly. Below is an outline of different kinds of bites and how to handle them.
Human bites- these should usually be treated as minor puncture wounds, and
the area should be washed thoroughly with soap and water and then bandaged.
Human bites can kill.
Marine creature bites- for bites and stings from creatures like jellyfish or
Portuguese-men-of-war you need to be careful. Common jellyfish stings are
usually not a big problem unless you are stung many times or are either very
young or very old.
You handle jellyfish stings much the same way as a Portuguese-man-of-war sting,
even though p-m-o-w stings are more serious and can sometimes be fatal if you
are stung too many times and do not receive the proper attention. Cover the
jellyfish, or broken off tentacles with sand and Very Gently remove them and
brush them off with a glove or piece of clothing. Do not touch them with your
bare hands. P-m-o-w tentacles are paper thin, and even if they have broken off
they will cling to you and continue to sting, hence the reason their stings are
considered more harmful. It is possible to become ill from their sting, so if you’ve
been stung by one make sure to seek medical attention quickly. If you are not
hypersensitive to stings such as these, then you may treat these wounds as follows
l Thoroughly wash the area and apply rubbing alcohol (or salt water) several times, while being
careful not to touch the area with your bare hands.
l Coat the area in a thick layer of baking soda and water paste, which may be removed (scraped
off) about 30 minutes later.
l Once you have removed the layer, you should reapply the rubbing alcohol or vinegar. Salt water
will also work if you have neither at hand.
If a stingray has stung you, then seek medical help immediately. Wash
the wound in fresh or salt water thoroughly and keep the wound submerged in
hot water while you get help.
If a larger animal such as a shark, or other toothed creature has bitten
you, refer to the animal bites section below.
Animal Bites- These can be superficial, but they can also be very serious.
Most bite and scratches from household pets are superficial and can be treated
with a simple washing of the wound, dab of antibacterial ointment and an
adhesive bandage. But sometimes, Fido and Fluffy get a bit too frisky and really
take a good bite out of you. When this happens, and when you are bitten by an
animal that is not a pet of yours, you need to follow a different procedure.
l Wash the wound well with soap and water unless there is heavy bleeding. Then
consult your doctor to determine if stitches are needed. If the wound appears
serious do not attempt to clean it yourself.
l If the wound is large or deep you should see your doctor as soon as possible, as the wounds
must be cleaned and bandaged properly to prevent the spread of bacteria and lower the risk of
infection. If the wound is large and deep, stitches will be needed. In some cases, a tetanus shot
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and antibiotics will be necessary.
l If swelling, bruising, extreme pain, increasing redness (sometime seen as
streaks), tenderness, warmth or drainage around the bite area occurs then
consult your doctor immediately.
l Also any flu-like symptoms, such as fever, exhaustion, and swollen glands
that occur soon after the bite or scratch should be reported to your doctor
as soon as they appear. This is crucial as it could be signs of infection or a
disease.
l If someone else’s pet bit you, you must notify the owner and determine
when the animals last rabies shot was. Vicious animals that were allowed to roam free should be
reported to the local health departments.
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FirstAidGuide.net - Blisters
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Blisters
What are blisters?
A blister is a minor injury that unless it becomes infected, is found in unusual place, or reoccurs
frequently can be treated at home without the assistance of a doctor. Blisters are formed by repeated
the rubbing and friction in a particular area, which then fills up with fluid. Because they are so often
exposed to friction the hands and feet are the most common place for blisters. Blisters will also form
more easily on skin that is warm and moist, as opposed to dry or soaked, which again makes hands
and feet an ideal place for blisters.
Types of blisters.
There are two main kinds of blisters, friction and burn, and both are treated the same way. Leave the
blister alone for a period of about 24 hours (you may cover it gently with an adhesive bandage to keep
it from getting broken.). If after this time the fluid has not been re-absorbed, and you can see no
apparent change in larger blisters then you may begin the following treatment.
Over small intact blisters you should place a blister bandage and leave them alone, as they should heal
quickly and you should not break them.
Larger intact (or ones with only a small tear) blisters are to be treated in the following way.
l Sterilize a needle or straight pin by heating it until it turns red in a flame, placing it in boiling
water or soak it in rubbing alcohol.
n Clean the blister with rubbing alcohol or antibiotic soap and water.
l After the needle has cooled, carefully pierce the blister on two opposite sides and press down
gently on the blister with a sterile gauze pad to drain the fluid.
l Do not remove the loose skin!
l Cover the area with an antibiotic ointment. Keep in mind that you may want to avoid products
containing Neomycin, which is known to cause allergic reactions.
l Then cover the blister with a blister bandage and change the dressing daily, or whenever it
becomes wet, loose, or dirty.
Damaged blisters?
If the blister is has a large tear in it…
l Then take sterilized, fine scissors and carefully, remove the loose skin after the fluid has been
drained.
l The area should then be thoroughly cleaned with antibacterial soap and water
l Put on antibacterial ointment and cover with a blister bandage.
Infected blisters?
If you see any of the following signs your blister may have become infected and you should go to a
doctor to receive the proper treatment.
l Pus draining from the blister
l Very red or warm skin around the blister
l Red streaks leading away from the blister.
Preventing blisters?
Blisters can be easily prevented, if the right steps are taken (no pun intended). For blisters on your
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feet, you should be sure that the shoes you buy are comfortable. The best time to buy shoes is in the
afternoon or evening as feet tend to swell during the day. Shoes that fit right should have about a
thumbs space in between your longest toe and the end of the shoe. If your shoes are too narrow they
can cause blisters on your big and little toes, if the toe box is too shallow they can cause blisters on the
tops of your toes, and if the shoe is too loose they can create blisters on the tops of your toes.
When buying shoes for a sport, make sure to wear the socks or padding you would normally
wear around your feet to make sure that the shoe will fit comfortably. Jog or walk around the store
before buying them and then wear them around the house for several hours to make sure they don’t
“rub” anywhere and cause uncomfortable friction.
Socks also help decrease friction in shoes, and socks made of synthetic materials remove
moisture from the feet better than wool or cotton socks. This moisture removal also decreases the
likelihood of getting a blister. If you know you feet will be sweating a lot, you can carry extra socks
with you to change when the first pair starts to become uncomfortable.
Another step that can be taken to prevent blisters is to apply a thin layer of petroleum jelly to
your feet. This will help decrease friction. This can also be used on your hands. Things like wearing
gloves when doing activities such as construction, landscaping, moving, and other activities where your
hands are exposed to friction will also help cut down on the likelihood of getting blisters

How do you treat serious reactions (anaphylactic and non anaphylactic)?
If you know you’re allergic to bee stings, it’s wise to carry the self-injectable antidote
epinephrine, better known as adrenalin. These prescription kits are sold under the names Ana-Kit,
EpiPen, and EpiPen Jr. (for children), among others. These syringes are injected into the front of the
thigh, or a muscle and work to constrict the blood vessels before more damage can be done. Most of
the kits come with only one syringe and on occasion more than one dose is needed. Because bee stings
can happen at almost any time during the spring, summer, and early fall it is important to keep several
kits on hand, especially if medical help is out of reach, for example camping trips, hikes, and on
vacations where territory and bugs are unfamiliar. Keep kits at home and in the car, and if your child is
allergic, leave a kit with the school nurse. Although this drug may stop a reaction and make you seem
alright it is very important to go to your doctor anyway as soon as possible to be sure. In some cases
the epinephrine is not enough and intravenous fluids or other treatments are needed. ALL cases of
anaphylactic shock, or suspected cases should report to the emergency room immediately! The longer
you wait the more damaging the effects.
If you or someone you know or live with is at risk of going into anaphylactic shock it is
important to know how to use the syringes. Ask your doctor for information about classes you can
attend to learn how, when, and where to administer these shots and save a life. It is also advised that
a Medic Alert bracelet or necklace be worn.
Signs of anaphylactic shock:
Reactions of this kind usually occur seconds or minutes after the sting is received, although a
few cases have not reacted for up to 12 hours. When one goes into anaphylactic shock, the blood
vessels dilate and begin to leak into the surrounding tissues, which may affect some organs. Below are
signs and symptoms to look for.
· The skin is the first place to look. Hives, itching, swelling, redness and a stinging or burning
sensation may appear. On the flip side, skin may also appear extremely pale.
· Because the blood vessels are leaking a person may feel lightheaded or faint. Some people will
lose consciousness because of a rapid drop in blood pressure.
· Sometimes the throat, nose, and mouth become swollen and breathing passages become
obstructed. The first signs of this are usually hoarseness or a lump in the throat. In some cases the
swelling is so bad the air supply is cut off and the person experiences severe respiratory distress.
· Another respiratory problem could be the constricting of the airways, giving someone the chess
tightness, wheezing and shortness of breath commonly associated with asthma.
· People may experience cramping (in women pelvic cramps may develop), diarrhea and nausea
and vomiting.
· Especially if the allergen was swallowed, the gastrointestinal tract often reacts.
· Sweating
· Rapid pulse
Causes of anaphylactic shock:
It is important to note that this allergic reaction (which, again, is very rare), is not caused only
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by bee stings. This reaction can be sparked by an injection, inhaling, swallowing, and being exposed to
an allergen that the person is known to be allergic to. Injected allergens could be bee stings, as
mentioned, certain vaccines prepared on an egg medium, penicillin, dyes used in diagnostic x-rays, and
allergen extracts used in the diagnosis and treatment of allergic conditions. They can also be sparked
by food allergies, even if only a small bite is taken. Skin contact with foods rarely causes an
anaphylactic reaction. Foods that are commonly associated with this reaction are peanuts and nuts,
seafood, and in children particularly, eggs and cows milk. Inhaled anaphylactic reactions are rare, but
have occurred from the inhalation of particles from rubber and latex gloves.
Prevention of anaphylactic shock:
The most important part of prevention is avoiding the allergen as best as you can. For food
allergies and insect bites this may be particularly difficult as food is presented in many different ways,
and insects are all around you. For some people immunotherapy is key. This therapy introduces small
amounts of the allergen to the person and increases the dose over time. This is a lengthy treatment
and takes at least five years, however it can be an invaluable form of protection as it is almost 100%
effective.
If your allergy involves bee stings it is important to note a few things about the bees. Honeybees can
only sting you once, their stingers get stuck in the skin and they must tear away that part of their
abdomen to escape. The bee dies shortly after delivering the sting. Luckily honeybees are not
aggressive, like some of their relatives, wasps, hornets, and yellow jackets tend to be, these bees will
only sting if they are disturbed or injured. The most common sting from these bees is when they are
stepped on. The best way to avoid that is to keep shoes on while walking or playing in areas where
honeybees forage, such as clover patches and flowerbeds.
Another few things to note about bees (and other stinging insects), is that they are attracted to bright
colors and strong scents. Insects seeking nectar are drawn towards bright colors, and perfumes. If you
are allergic to these stings it is recommended that you avoid hairspray, perfumes, and colognes and, in
the case of bees, bug spray. Bug spray will not deter bees, and since the scent is strong they may even
be attracted. You should also avoid areas where food is open to the environment such as garbage cans,
dumps, picnic areas etc. Another interesting fact about bees and color, is that black is an irritant to
bees, while blue is a comforting color, it is important to remember this when selecting bathing attire.