Glass Cleaner On Cubic Zirconia And Topaz Jewelry
As you likely know, stones like cubic zirconia (CZ) need to be clean to look the best. When clean, a nice CZ will sparkle and look great. However, when just a little dirt soils the back of the stone the shine quickly disappears. That is the nature of the stone. It simply does not have the ability to return light when dirty on the back(bottom of stone, called the pavilion) in the way a diamond does.
For cleaning most gemstones, glass cleaner should work just fine. Some people use toothpaste, of all things! I do not recommend that since toothpaste can be abrasive and can dull the metal.Glass cleaner is a generally good choice with one exception.
The Exception. Sterling Silver will react badly to ammonia. If the glass cleaner contains ammonia, do not use it on sterling. You may not notice any problems and this might be because the sterling has a protective plating of another metal on top of the sterling. The plate is very thin but durable and is there to prevent the ususal natural tarnish of silver.
Ammonia will speed up tarnish and can leave whitish spots on sterling. I would avoid getting the cleaner on sterling. If you need to, you may clean a stone set into sterling with a mild detergent such as “Joy” which is a dishwashing detergent. Never use soap since a soap film might be left behind.
The ingredients in glass cleaner are very much like those in some over-the-counter jewelry cleaners. By your discovery, you have found an effective method to clean the stones and save money at the same time. That is a good move. Keep in mind, no cleaners including glass cleaner should be used on stones which might absorb the cleaner or be affected by it. These are pearls and turquoise, for the most part. Wash these stone is a mild dish detergent and rinse well then dry gently with a soft cloth.
Topaz is perfectly safe for almost all cleaners except abrasive ones. Ammonia is fine for topaz and CZ and does a good job. As I said, do not use ammonia with sterling if that is the metal your gemstones are set into. In any case, rinse well with lukewarm water to remove all traces of cleaner and pat dry. That should do it. You may use a soft brush to get behind the gemstones.
I am very happy to see a person who is interested in caring for their jewelry. We see so many rings and other jewelry items where I work which are terribly dirty. Often, the settings are worn and the jewelry is too dirty for the owner to notice the danger of loose stones. People will say, “I never take off my jewelry”.
That is the biggest mistake they can make. Regular cleaning not only makes your jewelry look the best but also gives you a chance to check for wear on the settings and gently touch the stones to see if secure or loose. Caught in time, a stone may be easily and inexpensively tightened in the setting.
Let it go and the setting may have to be remade at much more cost. Good to know there are folks out there who do care enough to clean their jewelry regularly. Often times there are people that come in to have there jewelry cleaned, then we are the ones that have to tell them that there is a stone missing or that they are going to need a whole new setting for there stones because they never took care of there jewelry. Which in turn will cost them more too have to have there stones taken out and then put into another siting.
Gold Jewelry Discoloration
Did the dishwashing solution contain any ammonia? I find most do not contain ammonia are a safe method of cleaning jewelry, including pearls. If ammonia was there, that “could” account for some of the discoloration. Also, chemicals and salts in the air in the beach environment are known to cause problems with jewelry. Even in almost invisible amounts, these chemicals can work to cause smudges and discoloration on gold items. Generally, a regular cleaning like you did will prevent problems.
Is the bracelet gold? The color change is not a direct indication the item is not gold as marked. However, there should be a makers mark near the 14k mark. That is law at least in the U.S.A. and the mark should be there. Sometimes the mark is quite small or only a symbol of some sort, perhaps mixed with the 14k metal quality mark.
Do you have faith in the place the item was purchased? If reputable, there should be no problem and they might offer to clean and buff the bracelet or even replace it.
If purchased with no recourse, the only way to truly tell is to have a jeweler who will test gold run a test for karat on the bracelet. These test involve either a simple acid test or use an electronic instrument. The cost should be low. Call and check around before you go since some jewelers do not have anyone on the premises who does this testing. Almost any store with a working bench jeweler should be able to test the bracelet.
If this is gold, why the color change? One possibility and only a possibility is that the bracelet was given a quick flash plate of yellower high karat gold to make it look richer in the first place. We see lots of necklaces and some bracelets(lots with CZ stones) with a plate of very yellow high karat gold. This is all for merchandising to make the color more rich and perhaps more appealing. Unfortunately, repairs will easily remove that surface plate and leave the natural 14k color. The 14k color is just fine as it is! However, some of such plated items do show a more coppery look when the surface flash of gold is removed, perhaps an underlayer used in the plating process or the natural color of a less than attractive 14k gold mix which the maker knew would be flash plated to look rich yellow. I doubt the cleaning or polishing cloth removed the plate.
I simply suspect the environmental conditions led to the discoloration but that should be rather easily removed by a good wipe with a special jewelry polishing cloth. (Your cleanng would remove ocean air salts but not repolish the bracelet or remove tarnish unless a jewelry polishing cloth was used.) These special coths contain no messy polishes but do contain some chemical ingredients. One make is called “sunshine” cloth, used as is till totally soiled then simply disposed of. These cloths are available from jewelers and crafts stores. If not in stock, this cloth may be ordered for you.
My first suggestion is to have a jeweler who does metal tests check the bracelet if the item was not purchased locally and cannot be locally corrected. Then, if 14k as marked, get one of the cloths mentioned(or a similar one). Clean regularly just like you did being sure there is no ammonia in the cleaning solution.
A Brief Overview Of Ammonia Refrigeration Systems
Ammonia refrigeration systems are used quite frequently in facilities that provide industrial refrigeration. The ammonia used is actually anhydrous and there are many different types of foods, drugs, beers, ice creams, and more that we all enjoy on a regular basis kept in industrial refrigeration cooled by ammonia.
In fact, many things you use or eat on a daily basis were kept in ammonia refrigeration systems at some point in time before they made their way to your home. Other items that are used in ammonia refrigeration systems on a regular basis include fruit juice and soft drinks in their processing facilities, wineries, processing facilities for meats, fish, and poultry. Also petrochemical facilities and cold storage warehouses use ammonia refrigeration systems.
Ammonia refrigeration systems are not completely safe, however. Workers in processing plants are at risk of being exposed to ammonia spills. Ammonia is very dangerous to workers and it may cause many problems. Ammonia may affect workers through inhalation, skin contact, explosion, and even fires. As a result process hazard analysis is very important and companies focus on this for process safety management. Safeguards are important and must be kept in place at all times to ensure safety. Ammonia is a hazard and it must be handled properly.
Worker protection is very important because ammonia is so dangerous. In the past workers have been injured and even killed working in facilities with ammonia refrigeration. Liquid contact or vapor from ammonia may cause injuries or even kill employees so that is why it is so important to keep industrial refrigerators in proper order at all times. Otherwise catastrophic consequences may result. In fact, there are many programs developed by OSHA to assist companies using industrial refrigeration to keep employees safe. For example, OSHA discusses vent pipes and their failures to help companies realize where problems may arise. The same goes for inspection systems and how important they are to keep up to date and constant in companies using anhydrous ammonia.
OSHA has also recommended that all workers in industrial refrigeration plants wear protective clothing in order to protect them in case of a spill, leak, or other similar event. OSHA has also published information on fire safety, respiratory protection, control of hazardous energy, personal protective equipment, and the like.
With OSHA playing a role in ammonia refrigeration and how it is managed companies and employees are all kept safer. That is the most important thing and thanks to OSHA employees working with ammonia refrigerant are now safer than ever.
The Ammonia Cycle And Your Aquarium
What is the Ammonia Cycle?
The ammonia cycle - better known as the nitrogen cycle - is an essential part of the environment. In nature, ammonia is a product that is given out by organisms during their excretion process. However ammonia is toxic, and it is very hazardous to the ecology to leave it lying as it is in the environment. Nature itself takes care of things though. There are some bacteria present in the environment such as nitrosomonas and nitrosococcus that can reduce the ammonia to nitrites. Nitrites are solids with the general radical -NO2, but the problem is, even nitrites are toxic, especially to grazing animals. Nature again helps; another species of bacteria called the nitrobacter convert the nitrites into harmless nitrates, with radicals -NO3. The conversion of ammonia into nitrites and then into nitrates is called as ammonification.
But the process does not stop here. Denitrifying bacteria are involved in the environment, which convert all the residual nitrites and the nitrates into the free atmospheric form of nitrogen. In this form, the gas is released into the environment. Later this nitrogen will be fixed back into the soil, and then taken by plants, and then by animals, and the whole cycle with continue again.
Thus the ammonia cycle actually involves the circulation of nitrogen from the organisms to the environment and then back from the environment to the organisms.
Why is Ammonia Cycle Important in an Aquarium?
Most fish and other aquatic organisms are ammonotelic, i.e. they give out ammonia directly as their excretory product. This ammonia collects in the fish tank and, among other things, it might increase the basicity of the fish tank (which means the pH value will be increased). Any change in the pH value of the fish tank is obviously quite harmful to the inhabitants of the tank.
That is the reason why the ammonia produced in excess within the aquarium must be effectively removed. Hence, ammonia cycle becomes important.
How is Ammonia Cycle Maintained in the Aquarium?
The easiest way to keep your ammonia cycle going on in the aquarium is to introduce bacterial cultures into the water. One of the best ways to do this is to add a biological medium such as live rock or a biological bed. Sponge filters can be introduced in the fishless tank first on a biological bed and then allowed to live in the tank for about two to three days. This will promote the growth of the necessary bacteria required for the ammonia cycle. Later on, the fish can be introduced one after the other. It is necessary to bring in the fish one at a time, because that will allow the bacteria to get accustomed to neutralizing the pH value increase in the tank.
Some aquarists help in the ammonia cycling by actually adding some pure ammonia before they put the fish in. When such ammonia is added, the microorganisms within the tank will cycle this ammonia first, and so the cycle will already have set in before the fish are introduced.
There are ammonia cycling pumps available too, all of which work on different principles. If the number of fish in your aquarium is low, then replacing the water periodically could also be a good attempt at ammonia cycling.
Anhydrous Ammonia Spill Day
It looks like someone declared June 8, 2007 to be the day for serious Anhydrous Ammonia spills from refrigeration systems across the country. There were three separate instances of significant spills reported today. Mount Sterling, KY, Wyalusing, PA, and Milwaukie, OR all had releases in the last 24 hours. No one was killed, but a number of people were taken to the hospital, businesses were evacuated, and residents were told to shelter in place.
There were explosions associated with two of the incidents. There are reports that the ammonia leak at a Nestle Plant in Kentucky caused an explosion that blew down a wall at that plant; no injuries from the explosion or falling debris have been reported. The American Cold Storage facility in Oregon had an unexplained (as yet) explosion result in the ammonia leak. There were no reports of an explosion associated with the leak at Cargill Taylor Beef Plant in Pennsylvania.
Anhydrous Ammonia is favored in many large cooling systems because it has better heat transfer characteristics and is cheaper than the refrigerant gasses used in home cooling systems and refrigerators. The problem is that this material is very reactive and is classified as a Toxic by Inhalation gas. Fortunately, the gas is extremely irritating at well below the toxic level so that when a minor leak happens, unprotected people evacuate the area quickly with little urging. A catastrophic leak, however, can overcome people before they have a chance to get clear. This is partially because many people are temporarily blinded by less than lethal concentrations.
The food industry has long maintained that they should not have to comply with any handling restrictions on Anhydrous Ammonia required under various Federal laws, since they don?t actually handle Anhydrous Ammonia; it stays in a closed system. During the regulatory comment period they complained about being required to submit information under the new Chemical Facility Anti-terrorism standards based on the 7,500 pound Screening Threshold Quantity (STQ) listed in the proposed Appendix A, Chemicals of Interest, to 6 CFR part 27. Cooling systems having more than 7,500 pounds of Anhydrous Ammonia in the system would make that food processing company a ?Chemical Facility? under the rules of this regulation.
According to the EPA Risk Management Plan (RMP) guidance documents, 7,500 lbs of Anhydrous Ammonia released in 10 minutes time from a pressurized system (clearly a catastrophic leak, not a faulty valve) will have a plume with a toxic end point 3.2 miles down wind from the site of the leak (Table 9, 1.5 m/s wind speed). That means that anyone between the leak and 3.2 miles downwind could be exposed to dangerous concentrations of Anhydrous Ammonia.
Rather obviously, from the lack of casualties, none of these three release events came any where near 7,500 lbs in 10 minute release rate required for a 3.2 mile long toxic plume. There is nothing in any of the available article that tells anything about the release rate for these accidents, but from the description they did not seem to be catastrophic release events. But what about the explosion caused by the release in Kentucky?
Anhydrous Ammonia is a very reactive chemical, and even by itself can form an explosive mixture when mixed with air at concentrations of 16 to 25% Ammonia in air, though it would require a strong ignition source. It reacts to produce explosive by-products when it mixes with Chlorine, Bromine or Iodine. Violent reactions occur with Bleach or Peroxides. It also forms explosive compounds with Gold, Silver and Mercury. So, while explosions are not part of the normal operating conditions of refrigeration systems using Anhydrous Ammonia as a refrigerant, an explosion after a significant leak would not be totally unexpected.
Nutrition countdown: these top supplements will amp up your preworkout meals for maximum power and performance in the gym
It’s 30 minutes until your next workout. Quick, what should you take to ensure high-performance energy levels, monstrous strength and ample supplies of nutrients to kick-start muscle growth processes?
We stumped some of you, didn’t we? Plenty of bodybuilders start bashing the weights after hitting a fast-food drive-through, after wolfing down a protein bar or even while running on empty. Most guys simply don’t give a lot of consideration to their nutritional attack–even guys who will spend hours meticulously planning out exercises, sets and reps are often guilty of putting zero thought into the food and supplements that will actually fuel their training session.
That’s a mistake, and one you can put an end to right here. We’ve mapped out the nine top supplements for bodybuilders in preworkout mode, along with the best carb foods for stoking your body’s growth and energy furnace. Use this as your guide, and you’ll have improved power, energy levels, endurance and focus next time you train.
#1 WHEY PROTEIN
First on your list is supplying your body with critical amino acids needed not only as building blocks for muscle growth, but for energy during training. If your body uses the amino acids from whey protein, it won’t have to break down existing muscle protein to get aminos for fuel, which obviously could compromise your muscle size.
THE RESEARCH SAYS Drinking a whey protein shake immediately before you lift is even better for stimulating muscle growth than waiting until after the workout is over. Taking in a small amount of whey protein (without carbs) before you do cardio may also help you burn more fat when you exercise.
TIMING AND DOSAGE Having a whey protein before exercise is your best bet, as it is a quick-digesting protein, which means your body will get the aminos it needs, fast. Go with 20 grams (g) of whey protein isolate, hydrolysate or concentrate along with 30-50 g of carbs within 30 minutes of your workout.
#2 ARGININE
This amino acid is the main ingredient in almost every nitric oxide (NO) boosting product available. Arginine is readily converted in the body to NO.
THE RESEARCH SAYS Nitric oxide dilates blood vessels, which helps get more blood flow to working muscles. Enhancing blood flow to muscles right before a workout helps to deliver more nutrients, such as amino acids from whey protein, glucose and fats, and the anabolic hormones that rise during training, such as testosterone, growth hormone and insulinlike growth factor-I (IGF-I). Greater blood flow also means more water delivery to exercising muscles; since a muscle pump is essentially a result of muscle cells filling up with water from blood, more water supplied to the muscles results in a greater muscle pump.
TIMING AND DOSAGE No matter whether the product you take supplies L-arginine, arginine alpha-ketoglutarate, arginine ketoisocaproate, arginine malate or arginine ethyl ester, go with 3-5 g about 30-60 minutes before workouts. For maximal effect, on nontraining days take a dose in the morning and before bedtime.
#3 CARNOSINE
Carnosine is an amino acid supplement that is actually a dipeptide–two amino acids (beta-alanine and histidine) bound together. You can supplement with either carnosine or with beta-alanine and histidine for the same effects–greater muscle strength and endurance. That’s because, in muscle fibers, beta-alanine and histidine are combined to form carnosine.
THE RESEARCH SAYS Muscle fibers that have the highest levels of carnosine can produce the greatest amount of force and can produce the greatest amount of force and can contract for longer periods. Studies of athletes show that it is possible to increase muscle levels of carnosine by more than 80% with supplementation, but it can forestall fatigue. In the gym, this means you can get more reps with a given weight before reaching failure, or lift more weight for a certain amount of reps. Carnosine appears to work by buffering the byproducts that build up in muscles during exercise–those byproducts eventually cause muscles to fatigue. Carnosine also has been found to provide antioxidant properties, meaning it scavenges free radicals that could damage muscle cells; this protection helps muscle recovery.
TIMING AND DOSAGE Take 1-1 1/2 g of carnosine 30-60 minutes before workouts.
#4 CARNITINE
The supplement carnitine is considered an amino acid, but it’s not typical. It’s actually made from the amino acids lysine and methionine; vitamins C, B3 and B6; and iron. Carnitine is important for fat metabolism, as it is involved in carrying fat into the machinery in muscle, heart and brain cells, known as mitochondria, that burn it for fuel. Taking carnitine before workouts prompts your body to use more fat during the session.
THE RESEARCH SAYS University of Connecticut researchers have been integral in discovering carnitine’s importance to bodybuilders. One of their studies suggests that carnitine, like arginine, enhances blood flow to exercising muscles. However, the mechanism is likely different from arginine, which indicates that taking both supplements can offer additive benefits (i.e., it would be more valuable to take both of them rather than just one or the other). A more recent study from UConn suggests that carnitine enhances the number of androgen receptors in muscle cells responsible for binding testosterone in the muscle and initiating its effects on muscle growth and strength.
Sequential Unfolding of Individual Helices of Bacterioopsin Observed in Molecular Dynamics Simulations of Extraction from the Purple Membrane
Multiple molecular dynamics simulations of bacterioopsin pulling from its C-terminus show that its ?-helices unfold individually. In the first metastable state observed in the simulations, helix G is unfolded at its C-terminal segment while the rest of helix G (residues 200-216) is folded and opposes resistance because of a salt-bridge network consisting of Asp-212 and Lys-216 on helix G and Arg-82 and Asp-85 on helix C. Helix G unfolds inside the bundle because the external force is applied to its C-terminal end in a direction perpendicular to the surface of the membrane. Inversely, helix F has to flip by 180° to exit from the membrane because the applied force and the helical N-C axis point in opposite directions. At the highest peak of the force, which cannot be interpreted in single-molecule force spectroscopy experiments, helix F has a pronounced kink at Pro-186. Mutation of Pro-186 and/or the charged side chains mentioned above, which are involved in very favorable electrostatic interactions in the low-dielectric region of the membrane, are expected to reduce the highest peak of the force. Helices E and D unfold in a similar way to helices G and F, respectively. Hence, the force-distance profile and sequence of events during forced unfolding of bacterioopsin are influenced by the up-and-down topology of the seven-helix bundle. The sequential extraction of individual helices from the membrane suggests that the spontaneous (un)folding of bacterioopsin proceeds through metastable bundles of fewer than seven helices. The metastable states observed in the simulations provide atomic level evidence that corroborates the interpretation of very recent force spectroscopy experiments of bacteriorhodopsin refolding.
INTRODUCTION
Integral membrane proteins are involved in a wide variety of functions like photosynthesis, transport of ions and small molecules, and signal transduction. They either consist of a varying number of ?-helices (e.g., G-protein coupled receptors (1), aquaporin (2), and the ammonia channel (3)) or they adopt a ?-barrel fold containing between 8 and 22 ?-strands (4). The former are much more common than the latter, which are exclusively found in the outer membrane of Gram-negative bacteria. However, despite the relative abundance of membrane proteins among all proteins and despite the fact that they represent the majority of the targets for existing drugs (5,6), only a few structures have been solved so far. Moreover, the mechanism of folding and assembly within the membrane is not clear (7).
Bacteriorhodopsin (BR) is one of the most extensively studied integral membrane proteins (8-10). BR is a light-driven proton pump and its photoactive retinal, which is bound covalently through the Schiff base to Lys-216, is embedded in seven closely packed transmembrane ?-helices (termed A-G) arranged in an up-and-down topology (Fig. 1, (top). In the purple membrane BR adopts a trimeric state stabilized by the presence of lipids in the central compartment, which has a nearly cylindrical shape (11). High-resolution atomic force microscopy (AFM) topography of the cytoplasmic surface of a wild-type purple membrane shows that trimeric BR molecules arrange in a hexagonal lattice (12).
The forced unfolding and extraction from the purple membrane of BR and of its retinal-free form, bacterioopsin (BO), have been investigated in depth by combining AFM imaging with single-molecule force spectroseopy (12-15). AFM is a powerful method to shed light on mechanical protein unfolding or unbinding of a protein-ligand complex at the single molecule level, removing the averaging over large ensembles of molecules implied in other biophysical/ biochemical approaches. Two different AFM techniques are available to probe the mechanical resistance of biomolecules. In the force-ramp method, a time-dependent force is applied (16), while in the so-called force-clamp method, the force is held constant (17). Based on the force-ramp method, dynamic force spectroseopy (18) has provided a deep insight into the unbinding mechanism of a variety of biological complexes, such as the (strept)avidin-biotin complex (19) and the complex between L-selectin and various binding partners (20).
However, it is desirable to relate the information on unfolding or unbinding provided by the AFM techniques to the changes in tertiary and secondary structure. For this purpose, AFM observations can be complemented with molecular dynamics (MD) simulations, which describe the behavior of individual molecules at an atomic level of detail. Constant-velocity MD (termed also steered-MD and abbreviated as SMD) and constant force MD (CFMD) simulations mimic the force-ramp and the force-clamp method of AFM, respectively, and have been widely used to study protein-ligand unbinding (21-25) and protein unfolding (26-29). Very different timescales are involved in AFM experiments and SMD/CFMD simulations because force spectroscopy experiments are typically carried out on the millisecond timescale or slower while simulations are currently limited to nanoseconds. Nevertheless, simulations have helped to interpret consistently experimental observations and have been even used to formulate predictions subsequently verified by in vitro experiments (18,27,30-36).
BlueTec equals green for Mercedes-Benz: BlueTec system being used on buses in Europe; emissions technology coming to passenger cars and SUVs in U.S
The European Union’s stringent Euro 5 emission standards take effect in 2009 and compared to Euro 4, Euro 5 standards represent a further 43% reduction in nitrogen oxide (N[O.sub.x]) emissions. Earlier this year, the Mercedes-Benz Bus and Coach Unit delivered nearly 100 Citaro urban transit buses already meeting these stricter standards. These Euro 5 compliant buses feature DaimlerChrysler’s BlueTec diesel technology. Since early 2005, DaimlerChrysler has delivered over 20,000 Mercedes-Benz Actros, Axor and Atego heavy trucks with BlueTec diesel technology for Euro 4 and Euro 5 level emissions control.
Seven second-generation Citaro buses fitted with Euro 5 compliant Mercedes-Benz OM 906 LA/hLA engines were delivered to Verkehrsgesellschaft Breitenbach in Hamm, Germany. Another 90 similar Citaro buses are being delivered to Rotterdamse Elektrische Tram for service in Rotterdam, Netherlands.
There are two components to the BlueTec technology–enhanced engines and an integral exhaust gas aftertreatment system. For the Citaro application, the horizontally mounted, six-cylinder turbocharged diesel engine and its combustion processes have been optimized as far as possible to reduce emissions. This 6.4 L engine features electronic engine control, intercooled turbocharging and three valves per cylinder. The OM 906 LA/hLA engine in this application is rated at 279 hp with a peak torque of 830 lb.ft. at 1300 rpm.
In terms of aftertreatment, BlueTec is an umbrella term covering different technologies chosen for the operating characteristics of the particular application. It is modular so it can be used on trucks, buses, cars, SUVs and even hybrids, Mercedes-Benz said. Carbon monoxide and hydrocarbons emissions are reduced using diesel oxidation catalysts. Particulate matter is addressed though the use of a particulate filter, either as a separate element or integrated with one of the other BlueTec components. The installation of a larger sintered metal particulate filter in the buses is intended to ensure compliance with the more stringent Euro 5 emissions standard.
To meet Euro 5 requirements, N[O.sub.x] is reduced by a selective catalytic reduction (SCR) system with a urea-based injection system using an aqueous urea solution called AdBlue (thus the source of the name, BlueTec). When AdBlue, which is odorless, nontoxic and stored in an onboard tank, is injected into the pre-scrubbed exhaust, ammonia (N[H.sub.3]) is released. This causes the N[O.sub.x] to be reduced to nitrogen and water in the downstream SCR catalytic converter. Injection is controlled by the engine management system. To make the Citaro urban buses Euro 5 compatible, the size of the SCR catalytic converter was increased and the AdBlue injection quantity was adjusted accordingly. Incidentally, there are now around 1500 public-access AdBlue refueling sites in Europe, ranging from the Arctic Circle to southern Spain and from Ireland to Moscow. Several producers supply AdBlue.
The new Citaro buses can be distinguished by a front end that creates a visual link with the latest Mercedes-Benz touring coaches and rural service buses. The front-end flap and corner panels, including the headlamp housings, can now be opened, so the entire front end is accessible for routine maintenance and is easy to replace in the event of an accident. The rear end has also been modified.
The buses are fitted with disc brakes on all wheels, ABS and acceleration skid control (ASR), with a four-speed automatic transmission. The independent front suspension features lower wishbones and a standard-fit stabilizer. Finally, the turning circle is approximately 20 in. smaller than the first-generation Citaro bus.
The electronic self-leveling suspension system allows one side to kneel. Folding ramps and externally mounted, convenient request buttons make it easier for people with restricted mobility, older passengers and those with strollers. The 15 in. destination screens display the name of the next stop along with additional information, such as timetable changes and advertising. The Dutch buses also feature electrically extending wheelchair ramps, camera systems for monitoring the interior and digital bus-stop information and announcement systems.
On the lighter vehicle side, recognizing America’s demand for vehicles with good fuel economy without compromising utility, cargo capacity and performance, Mercedes-Benz has re-introduced several diesel-powered vehicles. It is now offering the E320 BlueTec luxury sedan, ML320 CDI SUV and R320 CDI Sports Touter.
These BlueTec diesels use a DeNOx catalytic converter rather than the more effective AdBlue injection process for N[O.sub.x] emissions. Therefore, these 2007 diesel models do not meet the emissions requirements of California, Maine, Massachusetts, New York, or Vermont and thus will not be available in these states.
According to DaimlerChrysler, the new-generation V6 diesel engine with CDI fuel injection technology yields up to 20 to 40% better fuel economy than comparable gasoline engines. The E320 BlueTec is the only diesel-powered luxury sedan available in the U.S. that can deliver an estimated 780 miles on a tank of fuel, the company said.
Epoxy Adhesive-More than Glue
How Is Epoxy Adhesive Different From Other Types Of Glue?
In order to make epoxy work, you must combing resin and a hardening agent to make the bond as strong as necessary. Until recently most adhesives were not very good at bonding two different materials such as metal and wood or in bonding non-porous materials like glass. But, with the synthetic matter contained in epoxies, you can do both of these types of jobs with ease. Most of the time, when you are making an epoxy adhesive, you do not mix the two parts together until you are ready to use them. Many are also thermo-activated, which means they also need heat in order to form the bonds.
How Long Have Epoxies Been Around?
In 1936, both S. O. Greenlee in the United States and Dr. Pierre Castan of Switzerland demonstrated the first epoxy adhesive. Since then, there have been many advancements in the field of adhesives and you can find many types both for home use and industrial use. Some that you might be familiar with are Krazy Glue, Super Glue, and Gorilla Glue.
Uses For Epoxy Adhesive
Uses for this type of adhesive include: fixing things like broken glasses, or bonding fiber optic cables. Epoxies are not bulky, are lightweight conform easily to the surface of the materials they are bonding. Therefore, they are perfect for many uses in the home and also in the workplace, because they are made to last.
What Cautions And Dangers Should You Be Aware Of When You Use An Epoxy Adhesive?
Exercise great caution that you are using the right kind of adhesive for the job. The wrong kind of adhesive can actually cause permanent damage to whatever you are trying to repair. Also, you should make sure that you have the area where you are using the epoxy adhesive clean and free from debris so that it does not get into adhesive. Take care to not get any adhesive on your skin because it may bond instantly and it is difficult to remove without great effort. With an epoxy adhesive like Crazy Glue it bonds instantly when it hits the air. If you do get it on your skin, you can try fingernail polish to remove it.
When you are using a two part epoxy adhesive you should mix it on a surface that you will not be using again if possible. The packaging for the epoxy adhesive often can serve this purpose. Mix the two parts quickly and apply them as soon as possible. Follow all of the instructions very carefully to ensure the best results.
If you are using some types of epoxies they can produce enough heat to cause whatever you are trying to bond to crack or bend. This is why it is essential that you are very careful when you are choosing which epoxy adhesive to use. Even the simplest epoxy such as those you would use at home can cause damage and may ruin the surface for future bonding attempts.
Where Can You Buy It?
You can find several types of epoxy at a hardware store, a home improvement store, or even some types of craft and hobby store. But, if you are unsure what type of epoxy you need, you can find a wealth of information online about what epoxies work best with different materials. The packaging should also have information as well that will not only help you to choose the right adhesive, but also how to apply it. If you still have questions, contact the customer service representatives at the company where the epoxy is manufactured to find out any additional information you may need.
Anhydrous Ammonia Spill Day
It looks like someone declared June 8, 2007 to be the day for serious Anhydrous Ammonia spills from refrigeration systems across the country. There were three separate instances of significant spills reported today. Mount Sterling, KY, Wyalusing, PA, and Milwaukie, OR all had releases in the last 24 hours. No one was killed, but a number of people were taken to the hospital, businesses were evacuated, and residents were told to shelter in place.
There were explosions associated with two of the incidents. There are reports that the ammonia leak at a Nestle Plant in Kentucky caused an explosion that blew down a wall at that plant; no injuries from the explosion or falling debris have been reported. The American Cold Storage facility in Oregon had an unexplained (as yet) explosion result in the ammonia leak. There were no reports of an explosion associated with the leak at Cargill Taylor Beef Plant in Pennsylvania.
Anhydrous Ammonia is favored in many large cooling systems because it has better heat transfer characteristics and is cheaper than the refrigerant gasses used in home cooling systems and refrigerators. The problem is that this material is very reactive and is classified as a Toxic by Inhalation gas. Fortunately, the gas is extremely irritating at well below the toxic level so that when a minor leak happens, unprotected people evacuate the area quickly with little urging. A catastrophic leak, however, can overcome people before they have a chance to get clear. This is partially because many people are temporarily blinded by less than lethal concentrations.
The food industry has long maintained that they should not have to comply with any handling restrictions on Anhydrous Ammonia required under various Federal laws, since they don?t actually handle Anhydrous Ammonia; it stays in a closed system. During the regulatory comment period they complained about being required to submit information under the new Chemical Facility Anti-terrorism standards based on the 7,500 pound Screening Threshold Quantity (STQ) listed in the proposed Appendix A, Chemicals of Interest, to 6 CFR part 27. Cooling systems having more than 7,500 pounds of Anhydrous Ammonia in the system would make that food processing company a ?Chemical Facility? under the rules of this regulation.
According to the EPA Risk Management Plan (RMP) guidance documents, 7,500 lbs of Anhydrous Ammonia released in 10 minutes time from a pressurized system (clearly a catastrophic leak, not a faulty valve) will have a plume with a toxic end point 3.2 miles down wind from the site of the leak (Table 9, 1.5 m/s wind speed). That means that anyone between the leak and 3.2 miles downwind could be exposed to dangerous concentrations of Anhydrous Ammonia.
Rather obviously, from the lack of casualties, none of these three release events came any where near 7,500 lbs in 10 minute release rate required for a 3.2 mile long toxic plume. There is nothing in any of the available article that tells anything about the release rate for these accidents, but from the description they did not seem to be catastrophic release events. But what about the explosion caused by the release in Kentucky?
Anhydrous Ammonia is a very reactive chemical, and even by itself can form an explosive mixture when mixed with air at concentrations of 16 to 25% Ammonia in air, though it would require a strong ignition source. It reacts to produce explosive by-products when it mixes with Chlorine, Bromine or Iodine. Violent reactions occur with Bleach or Peroxides. It also forms explosive compounds with Gold, Silver and Mercury. So, while explosions are not part of the normal operating conditions of refrigeration systems using Anhydrous Ammonia as a refrigerant, an explosion after a significant leak would not be totally unexpected.
Just maybe, DHS was correct in setting the STQ limit for Anhydrous Ammonia at a low enough level so that some refrigeration plant users could be labeled as Chemical Facilities.