Millions of American women suffer from hot flashes during menopause, but not many realize that diet can have a lot to do with it. Fortunately, hot flashes do not have to be an inevitable part of menopause. In fact, women in some cultures -- namely in Asia -- rarely experience discomfort from hot flashes at all. What's their secret? It could very likely be what's on their dinner plate.

Research indicates that soy, a significant element in the traditional Japanese diet, may be useful in preventing hot flashes in women. Edible beans, especially soybeans, contain the compounds genistein and daidzein, which are estrogenic and help control hot flashes. That may explain why only 7 percent of menopausal Japanese women suffer from hot flashes, as compared to 55 percent of women living in the United States, according to Dr. Lindsey Berkson's estimates in "Hormone Deception."

In fact, there is no Japanese word for "hot flashes." "Healing With Vitamins" author Alice Feinstein writes, "If you're fed up with menopause, move to Japan. In the Land of the Rising Sun, hot flashes and night sweats are virtually unheard of. Researchers believe that it has more to do with their traditional diet. Besides providing more vegetable protein and less animal protein than a Western diet, it's also low in fat and high in soy products such as tofu. These foods are rich in plant compounds known as phytoestrogens, which seem to mimic some of the biological activities of female hormones."

In addition to soy and tofu products, women can help combat hot flashes by eating more calcium-rich foods, magnesium-rich foods and foods rich in vitamin E -- like cold-pressed oils, green leafy vegetables, nuts and almonds, as well as plenty of mineral- and fiber-rich foods, like whole grains and fresh vegetables. Janet Zand, Allan N. Spreen and James B. LaValle -- authors of "Smart Medicine for Healthier Living" -- suggest women who suffer from hot flashes add sea vegetables to their diets. "The minerals in these foods replenish necessary electrolytes lost through perspiration," they write.

During menopause, it is also important for women to get plenty of water. "One of the best things you can do during this time is to be sure to drink plenty of quality water -- at least 2 quarts daily," writes Phyllis A. Balch, author of "Prescription for Dietary Wellness." "Drinking water replaces fluids lost to perspiration during hot flashes and can even prevent or minimize the hot flashes themselves."

Foods to avoid to prevent hot flashes
Perhaps as important as which foods women should eat to prevent hot flashes are those foods they should avoid. Many foods are thought to contribute to or worsen discomfort from hot flashes. Alcohol, caffeine, excess sugar, dairy products, meat products and spicy foods rank among the top aggravators of severe hot flashes as well as mood swings.

In Prevention Magazine's "New Choices in Natural Healing," Eve Campanelli, a holistic family practitioner in Beverly Hills, Calif., says, "Hot flashes often flare up when women drink wine or coffee, which acidifies the blood and strains the liver. One way to avoid this acidification is to cut down on these beverages and to drink more fresh vegetable juices, which counteract the effect by alkalinizing the system."

Certain lifestyle changes can also help ease hot flashes. For example, regular exercise can help alleviate some women's discomfort. Also, it pays to quit smoking. According to "Natural Cures and Gentle Medicines" by the editors of FC&A Medical Publishing, "A recent study at the Baltimore Veterans Affairs Medical Center found that women who smoke have significantly more hot flashes than nonsmokers."

The good news here is that if you are a woman going through menopause, hot flashes are within your control. It may take some diet and lifestyle changes on your part, but you don't have to suffer through hot flashes and accept them as a "normal" part of that time in your life. You can fight back with food, and, best of all, the foods you eat to help curb hot flashes will benefit your overall health as well.

Should women still take calcium supplements to help prevent osteoporosis? Yes, according to the June issue of Mayo Clinic Health Letter.

Mayo Clinic doctors continue to recommend that women consume adequate daily amounts of calcium and vitamin D through diet, supplements, or both, even though recent findings from a large research trial question whether calcium and vitamin D alone can adequately protect women’s bones. The Women’s Health Initiative study found that women taking calcium may still be at risk of fracture if they have other factors that compromise bone health.

Bone thinning due to osteoporosis affects 8 million women and 2 million men in America. People often don’t know they have the disease until a bone breaks.

Osteoporosis risk factors include:

Family history -- Your risk increases if your parents or siblings have had factures due to bone thinning.

Body type -- Thin or small-framed people -- those who weigh under 129 pounds much of their adult life -- are at higher risk.

Taking certain medications -- Long-term use of corticosteroid drugs, some antiseizure medications and blood thinners can adversely affect bone health.

Lifestyle factors -- Tobacco use, alcohol use, an inactive lifestyle, and low calcium and vitamin D intake can increase risk of osteoporosis.

Other medical conditions -- A dysfunctional thyroid or parathyroid glands, inflammatory types of arthritis such as rheumatoid arthritis, or Type 1 diabetes may contribute to bone loss.

Although supplements alone may not adequately protect against osteoporosis, calcium is still an important part of a healthy diet.

As a general rule, daily intake should be 1,500 milligrams of elemental calcium and at least 400 international units (IU) of vitamin D up to age 75, then increasing vitamin D to 600 IU after that. In addition, regular weight-bearing exercises are important to bone health.

New research shows calcium in food might do more to protect bones than supplemental calcium in pill form, according to results presented at the IOF World Congress on Osteoporosis in Toronto, Canada. Bones lose calcium as they age, making them vulnerable to osteoporosis and fractures.

"We found that people who take just dietary calcium, or a combination of dietary calcium with supplements, have better bone density than those who take supplements alone," explained Dr. Reina Armamento-Villareal of the Washington University School of Medicine, St. Louis, MO (conference abstract P696). "So we think dietary sources are better than supplemental sources by themselves."

In separate presentations, researchers from the Netherlands report that vitamin D supplements reduce fracture risk only in the presence of additional calcium; a new study finds vitamin D deficiency is widespread among European women; and researchers from California add to a growing consensus that high protein foods also promote bone health.

IOF's Bone Appetit campaign, a global initiative focused on the role of nutrition and food in bone health, to be launched on World Osteoporosis Day 2006, 20 October, make these findings especially timely.

Dietary calcium more beneficial than calcium supplements

Clues to Armamento-Villareal's discovery were identified in women split into three groups: one that got calcium from supplements only; another that got it from food only; and a third that got calcium from both supplements and food. Dietary sources were associated with high levels of active estrogen metabolites in urine, which is important because estrogen builds bone mass during youth and prevents bone loss during aging. "And we believe that if urinary levels of estrogen metabolites are high then estrogen levels in the body are also high," Armamento-Villareal said.

According to Armamento-Villareal, dietary calcium appears to be optimally absorbed by the body. But Armamento-Villareal cautioned the study didn't reflect calcium intake patterns over a lifetime, so some uncertainties about the long-term differences between dietary and supplemental calcium remain.

"Our future plan is to conduct a two to three year study comparing their effects during growing years to determine if one source of calcium is better than the other in building bones," she said.

Bone fracture, vitamin D, and calcium

Calcium's bone strengthening benefits don't accrue in isolation--vitamin D also promotes healthy bone mass by enhancing calcium absorption. Now, researchers from Belgium and the Netherlands report that high dose vitamin D supplements taken for osteoporosis prevention and treatment need sufficient calcium to be effective (conference abstract OC21).

The discovery builds on findings by Heike Bischoff-Ferrari from the Geneva University Hospital in Switzerland, who showed previously that supplemental vitamin D at doses of 800 international units or more protects against bone fractures. The Bischoff-Ferrari, et al. study was unable to assess the role of calcium in that protection, however.

Dr. Steven Boonen of the Leuven University Center for Metabolic Bone Diseases, in Belgium, and colleagues from Brussels University and Amsterdam University in the Netherlands, followed up with a broad literature search addressing the role of both calcium and vitamin D protection against hip fracture risk. The investigation showed that even at 800 international units per day, vitamin D could not protect against hip fracture in the absence of additional calcium. "Our meta-analysis shows there are two requirements for vitamin D to be effective," Boonen said. "First, you need the appropriate dose of vitamin D, as indicated by Ferrari, et al., and second you have to combine that dose with calcium."

Not Enough Vitamin D

In a different study, Dr. Olivier Bruyere of the University of Liege, Belgium, and his colleagues showed that most post-menopausal women living in Europe may be deficient in vitamin D, putting them at elevated risk of bone loss and fractures (conference abstract P142SA). Experts suggest the body needs at least 50 to 80 nanamoles per liter of vitamin D in blood serum for optimal bone health.

Bruyere and his colleagues analyzed vitamin D levels in 8,532 European postmenopausal women. Among the women, nearly 80% had circulating vitamin D levels below the high end of the acceptable range. Roughly one third of the women had levels lower than 50 nanamoles per liter, suggesting they have a serious risk of osteoporotic fractures.

Bruyere said the findings were consistent regardless of whether the women lived in sun-drenched countries or not. This is remarkable because vitamin D is produced in the skin by a reaction that requires sunlight. "That's one of the interesting outcomes of our study,"

Bruyere says. "We tested women from France, Belgium, Denmark, Italy, Holland, Hungary, Spain, the UK, and Germany but the findings were independent of latitude. So, based on that, we could hypothesize that vitamin D levels might be low all over the world."

The researchers observed identical levels of vitamin D deficiency in women aged lower than 70. Bruyere suggests these complimentary findings indicate that age has little bearing on the degree of deficiency. "Even young post-menopausal women should take some form of vitamin D supplementation," he said. "Supplements should not be restricted just to the elderly."

Is Protein Good for your Bones?

While the protective effects of calcium and vitamin D have been repeatedly demonstrated, the role of dietary protein is less clear. Some studies suggest too much protein heightens fracture risk, in part by causing calcium to leach from the bones. But insufficient protein might also increase fracture risk by reducing bone mass.

In new research, Donna Thorpe and colleagues from Loma Linda University, California report that protein protects against wrist fracture in post-menopausal women (conference abstract P111). The study compared dietary preferences disclosed by 1,865 women during the mid-1970s, with their incidence of wrist fracture over the next 25 years. In what Thorpe describes as the study's strongest finding, high-protein vegetable sources--including nuts, beans, soy, and commercial vegetarian dishes--protected vegetarian women from wrist fracture. Therefore, Thorpe said, as long as vegetarian women get enough dietary protein, they won't increase their risk of osteoporosis, as some have suggested. Cheese and meat consumed three times a week or more were also found to be protective." As women age, they tend to eat less protein, so this study tells me we that we have to get sufficient dietary protein to those who are at high risk for fracture," Thorpe said.

Can bones remember? According to new research presented at the IOF World Congress on Osteoporosis in Toronto, Canada they can. Not in the traditional sense, of course, but in that their vulnerability to osteoporosis and fractures depends on how the bones developed during pregnancy and childhood, according to Dr. Kassim Javaid of the MRC Epidemiology Resource Center, in Southampton, UK (conference abstract P108).

These findings come at a time when IOF is preparing for World Osteoporosis Day 2006. The event, which will be celebrated on October 20 by IOF's members in 85 countries, will focus for the first time on the role of nutrition in building bones, with the theme "Bone Appetit."

Poor skeletal growth during infancy can increase risk of later-life fractures

Javaid and colleagues previously demonstrated an association between poor skeletal growth in older children and increased fracture risk among the elderly. Now, the researchers find that poor skeletal growth during infancy and early childhood also enhances the risk of future fractures. "Now we have evidence that the bone mass you have at the age of 80 reflects what you started with very early in life."

To produce these findings, Javaid et al. compared weight and length data from 13,345 children (6,370 women) born in Helsinki between 1934 and 1944--both at birth and at varying childhood intervals--with their recorded hip fractures during old age. The researchers found that children whose weight was low relative to their length during infancy and early childhood had more hip fractures later in life.

Javaid cautions that weight's source--meaning the amount contributed by fat versus muscle mass--was not investigated. Therefore, children won't necessarily lessen their risk of osteoporosis by gaining fat, he said. Moreover, separate findings from a study of Caucasian and Chinese adults, led by Dr. Hong-Wen Deng of the University of Missouri, in Kansas, City (Conference abstract P152), suggest that weight derived from muscle mass contributes to bone density while excess fat contributes to bone loss, for unknown reasons. "The distinction [between the roles of muscle mass and fat in bone strength] has profound implications for public health and we're looking into that now," Javaid said. "The key point is that you want to make sure children maintain adequate growth as they get older."

Maternal Vitamin D Levels and Infant Bone Density

In a different study, Nicholas Harvey of the MRC Epidemiology Resource Center, in Southampton, UK, offered evidence showing that children born to mothers with higher vitamin D levels during pregnancy have stronger skeletons (conference abstract OC9). Focusing on subjects from the Southampton Women's Survey, which includes cohort of women aged 20-34, Harvey and colleagues compared maternal vitamin D levels during late pregnancy with infant bone density in 556 babies (286 males) soon after birth. They also took placental samples and analyzed them for levels of calcium transporter, which is a protein that carries calcium from the mother to the developing child. Like vitamin D, calcium is necessary for building strong bones.

According to Harvey, the study yielded a pair of complementary findings:

First, women who were vitamin D deficient tended to give birth to girls with low-density bones. Harvey said he's unsure why the finding was limited to girls, but he adds the gender difference might disappear in a larger study.

In a second finding, the researchers showed that rising levels of calcium transporter predict higher infant bone density. "What we hypothesize is that the mother's vitamin D levels somehow influence the amount of calcium transporter in circulation," Harvey said. "And if calcium transporter levels are low, then the infants don't get enough calcium, and their bones become weaker as a result."

Despite the finding, Harvey was reluctant to propose that women should take vitamin D supplements during pregnancy. That question should be investigated in further research, he said. "We think it would be safe but we can't recommend that type of intervention until we study it further."

Before you reach for the antacids to deal with troublesome heartburn, you might want to consider simply changing your eating habits. Most people are aware that eating too quickly or eating certain foods can trigger heartburn, yet few people are willing to change how and what they eat. Instead, they chow down as usual and then turn to their heartburn medication for relief. However, this is not the best way to tackle heartburn or indigestion, and, in fact, some of the very medications that claim to ease heartburn may actually make things worse.

Heartburn occurs when foods mix with acid to form a liquid that rises into the esophagus, causing chest pain or a burning sensation in the stomach. Antacids effectively "block" stomach acid, but at the same time, they block the absorption of nutrients and can hinder proper digestion, possibly making indigestion worse, according to Phyllis A. and James F. Balch in "Prescription For Nutritional Healing." In fact, the millions of Americans who take antacids to treat their heartburn are actually making a big mistake, according to Pamela Sky Jeanne, a naturopathic doctor from Oregeon. "One of the worst things you can do for your health is take an antacid," Jeanne says in Bill Gottlieb's "Alternative Cures." Jeanne explains, "That's because, in order to break down proteins into amino acids that are usable by the body, you must have sufficient hydrochloric acid in your stomach."

Besides interfering with digestion and nutrient absorption, both prescription and over-the-counter heartburn medications can have startling side effects. According to Phyllis and James Balch, many popular antacids contain aluminum compounds, which can cause constipation; magnesium compounds, which can cause diarrhea; sodium bicarbonate, which can cause gas and bloating; and calcium bicarbonate, which can actually cause the stomach to create more acid than usual once the antacid wears off.

Other heartburn medications may have more serious side effects. In "Graedons' Best Medicine," by Joe Graedon and Dr. Teresa Graedon, there is an account of a woman whose doctor prescribed her Reglan and Pepcid for her severe heartburn. Within days after she started taking the drugs, she began experiencing muscle spasms in her neck and shoulders, and a few weeks later she began experiencing uncontrollable muscle twitching, insomnia, hallucinations and even thoughts of suicide. When doctors could not reverse these symptoms with other prescription drugs, they became so severe that the patient temporarily checked herself into a psychiatric ward temporarily, not realizing at the time that she was having an adverse reaction to her heartburn medications.

Heartburn medicines are far from completely safe, and in some cases, they can even be deadly. Gottlieb writes, "A popular heartburn drug, used by more than 30 million people since 1993, has caused 70 deaths and 200 other incidents of heart problems, and, says the government; it should be used 'only as a last resort.'"

So, what is the first resort in heartburn treatment? Aim to prevent it in the first place, and for that, a change in eating habits is a good place to start. Many foods have a reputation for causing heartburn, including onions, garlic, hot and spicy foods, fatty or greasy foods, fried foods and highly acidic foods, like tomatoes and citrus. Chocolate and coffee are also common culprits. In addition, the way you eat is sometimes just as important as what you eat. People who eat especially quickly, who lay down after a big meal or who simply eat too much, are often more prone to heartburn. When you eat too much too fast, without chewing well, the stomach must produce more acid to break down food, creating problems for you down the line. Therefore, in addition to paying attention to the types of foods you eat, and avoiding those that trigger heartburn, you must also be aware of portion size and how quickly you eat.
If you do start to feel heartburn coming on, one of the first things you should do is drink water. F. Batmanghelidj in "Water for Health Healing" writes that heartburn really begins as just "thirst pains" -- a signal of a water shortage in the body. Batmanghelidj suggests treating this pain with water rather than medication.

Finally, it is important to bear in mind that it is not just food choices that can contribute to heartburn. Stress can also be a factor, as well as any prescription or over-the-counter drug you might be taking. This may surprise some people, but the drugs you take can lead to indigestion and heartburn. Aspirin, for example, has been shown to contribute to heartburn when taken in high doses, as has Ibuprofen. Anti-inflammatory drugs often cause heartburn in addition to more serious problems, such as death from sudden gastric hemorrhage. Certain calcium-channel blocking drugs, asthma drugs, beta-blocking drugs used to lower blood pressure and anticholinergics used to treat Parkinson's Disease may also cause heartburn, as can birth control pills, diazepam, nicotine, nitroglycerine, progesterone, provera and theophylline.

With the number of people eating poor diets and taking multiple prescription drugs in this country, it is no wonder, according to statistics given by Drs. Marc R. and Michael R. Rose in "Save Your Sight," that more than half of all people over 40 experience heartburn once a month., according to Drs. Marc R. and Michael R. Rose in Save Your Sight. If you frequently suffer from heartburn, it may be time to reevaluate what's in your diet or what's in your medicine cabinet. Talk to your doctor about how you can reduce your risk just by changing your lifestyle.

Higher levels of calcium in the blood are associated with less severe stroke and better outcome, according to research that will be presented at the American Academy of Neurology 58th Annual Meeting in San Diego, Calif., April 1 – 8, 2006.

Calcium and magnesium are intricately involved in the pathways of cell death in models of stroke, and high dietary intake of these minerals has been associated with a reduced risk of experiencing a stroke according to lead scientist Bruce Ovbiagele, MD, of the Stroke Center and Department of Neurology at the University of California, Los Angeles. This association led Ovbiagele to ask whether levels of serum calcium and magnesium might predict the severity and outcome in patients presenting with a stroke.

Ovbiagele’s group studied 240 consecutive patients who were seen at the UCLA Stroke Center within 24 hours of their stroke. Patients were classified into four groups, based on the level of calcium and magnesium in their blood. Researchers measured stroke severity at the time that patients were admitted into the hospital and how well they functioned upon being discharged.

The findings indicated that while there was no correlation with magnesium, higher calcium was strongly related to both lesser severity at admission and better outcome at the time patients left the hospital. Patients with the highest calcium levels had strokes only one-third as severe as those with the lowest level, and were 50 to 70 percent less likely to have a poor functional outcome.

The results remained significant after correcting for a wide variety of other factors known to influence stroke risk and severity, including age, prior use of anti-stroke drugs, and type of stroke.

“These results suggest a connection between high calcium in the blood and reduced cell death from stroke,” said Ovbiagele. “However, it is not yet known whether modifying dietary calcium in people at risk for stroke may help protect against poor stroke outcome.”

Preeclampsia, the development of high blood pressure and protein in the urine during pregnancy and its more severe complications such as eclampsia, can threaten the lives of both mother and child. While there is no therapy to prevent preeclampsia, a link to calcium deficiency has been suggested. In a study published in the March issue of the American Journal of Obstetrics and Gynecology, researchers across the globe, under the auspices of the World Health Organization (WHO), investigated whether a calcium supplement could reduce the complications and mortality from this condition.

Over 8300 women with low dietary calcium (<600 mg/day, about half of that recommended during pregnancy) were selected for the study. The subjects were randomly divided into two groups that had similar gestational ages, demographic characteristics, and normal blood pressures before treatment started. Half were given 1.5g of a calcium supplement per day and half received a placebo.

While the incidence of preeclampsia was not statistically different in the supplemented women, eclampsia, other severe complications and severe gestational hypertension were significantly lower. Overall, the "severe preeclamptic complications index" and the "severe maternal morbidity and mortality index," including all severe conditions, were also reduced with calcium.

Preterm and early preterm delivery (<32 weeks) tended to be reduced among women ¡Ü20 years of age who were at highest risk for low calcium and complications. It is very important to note that neonatal mortality was also lower in the calcium group.

This multicenter, randomized, placebo-controlled, double-blind trial was performed at antenatal care centers located in Rosario, Argentina; Assiut, Egypt; Nagpur and Vellore, India; Lima, Peru; East London and Johannesburg, South Africa; and Ho Chi Minh City, Vietnam. These centers are part of the WHO Maternal and Perinatal Research Network, each having extensive clinical trial experience.

Writing in the article, Jose Villar, MD, states, "This large randomized trial in populations with low calcium intake demonstrates that while supplementation with 1.5 gm calcium/day did not result in a statistically significant decrease in the overall incidence of preeclampsia, calcium significantly decreased the risk of its more serious complications, including maternal and severe neonatal morbidity and mortality, as well as preterm delivery, the latter among young women."

At the right dose, vitamin D is important for bone development and may help protect against the development of several cancers, particularly colorectal cancer. However, large quantities designed to exploit the vitamin’s anticancer properties can lead to a toxic overdose of calcium in the blood. Now, research done at Georgetown University’s Lombardi Comprehensive Cancer Center indicates that it may be possible to separate the anticancer properties of vitamin D from its other functions.

Their study, reported in the journal Molecular Cell, found that mutant forms of the protein that binds to vitamin D in the cell do not allow vitamin D to promote bone development and calcium transport but do permit it to regulate an oncogenic protein known as beta catenin. Some modified forms of vitamin D itself, which do not alter bone and calcium, were also found to regulate beta-catenin.

“We found that we might be able to separate the two functions at the molecular level, and this raises the possibility that vitamin D can be chemically modified into a drug that will only have anticancer effects,” said Professor Stephen Byers, Ph.D. He and Salimuddin Shah, Ph.D., led an international group of investigators in this study.

The human body produces a lot of vitamin D from a brief exposure of the sun. The vitamin is made in the skin when a cholesterol-like molecule interacts with ultraviolet light. It has long been known that a lack of vitamin D can lead to the bone deformities associated with rickets, and the vitamin helps maintain calcium and phosphorous levels in bone and blood. Too much vitamin D, however, can spill calcium into the blood and lead to heart disease and death.

Population studies have also uncovered an interesting fact — that the risk of developing colon cancer is lower in people who live in sunny climates. Epidemiology studies have indicated that vitamin D is responsible for the protective effect of sunlight exposure on the incidence of several other cancers besides colon, including breast and prostate.

Byers and the research team suspected that beta catenin may interact with vitamin D in some fashion because of another known fact — activation of beta catenin causes most colon cancers.
Related book:
The Healing Power of Sunlight and Vitamin D: an exclusive interview with Dr. Michael Holick
In this interview, Dr. Holick reveals fascinating facts on how vitamin D is created and used in the human body to ward off chronic diseases like cancer, osteoporosis, mental disorders and more.
To help them understand what vitamin D is doing in the cell, the researchers studied findings by other scientists who had looked at families who develop rickets due to an inherited mutation in their vitamin D receptor. Most of these patients had both rickets and alopecia (baldness). However a small number of families had mutations in the receptor which only led to rickets. “We know beta catenin is also involved in regulation of hair growth and we wondered if these particular mutations might also allow the receptor to regulate beta catenin,” Byers said.

“We found a mutation which caused rickets but not alopecia but which still allowed beta catenin to bind to the vitamin D receptor,” he said. This suggested to the researchers that it may be possible to separate the anti-cancer role of vitamin D from its effects on bone and calcium.

If a drug mimic of vitamin D can be developed, it could prove useful in preventing some cancers at their earliest stages, but would probably not offer any therapeutic benefit for later stage cancers, Byers said. “That’s because we know that by the time colon cancer is well advanced it fails to respond to vitamin D.”

The new Parsum IPP70 in-line particle size analyser is a new addition to the Parsum range available from Malvern Instruments, to measure particulate materials in the size range 50 to 6000 microns
The new Parsum IPP70 in-line particle size analyser is a new addition to the Parsum range available from Malvern Instruments. The new probe extends the variety of applications for which Parsum systems provide ideal solutions for particle measurement. Based on the theory of spatial filter velocimetry, the IPP70 measures particulate materials in the size range 50 to 6000 microns.

Robust and easy to use, it is suitable for the continuous monitoring of a range of unit operations, including wet and dry granulation, coating and spray drying.

The IPP70 probe is inserted directly into a process line or vessel.

It has been used successfully for monitoring both batch and continuous processes, for materials as diverse as polyethylene and washing powder.

The instrument continuously tracks Dv(10), Dv(50) and Dv(90) making it ideal for end-point detection, process control and process optimisation applications.

The fibre optics at the heart of the IPP70 deliver consistent measurement at high particle loadings.

Sensitivity to fluctuations in loading is low, making this an extremely robust solution.

Highly accurate data is produced at a measurement rate up to 15000 particles per second.

A rugged outer design protects the IPP70 from the process environment, for proven high reliability.

New software delivers user interfaces that are designed specifically to meet the needs of both the process and the research environment.

A series of LEDs allows the detection of contamination or material build up on the probe without the need to remove the instrument from the process, so forewarning the operator of any developing problems.

A Zetasizer Nano particle characterisation system is one of several analytical solutions available to researchers at BegbrokeNano, a new UK centre offering facilities for materials characterisation
A Malvern Zetasizer Nano particle characterisation system is one of a number of analytical solutions available to researchers at BegbrokeNano, a new UK centre offering facilities for materials characterisation to companies involved in the exploitation of Micro Nano Technology. Located at the Oxford University Begbroke Science Park, BegbrokeNano was opened officially on 26 July 2006. In developing this new facility, the Department of Materials at the University of Oxford has joined forces with leading instrument manufacturers to provide a dedicated solution for the analysis of micro and nano scaled materials and structures.

BegbrokeNano is supported by the DTI under the UK Micro and Nano Technology Network (MNT), offering the MNT community access to unrivalled facilities for materials characterisation.

Dr Alison Crossley, Manager of BegbrokeNano said: 'This new centre will offer state of the art facilities to companies developing nanotechnology, and build on our aim to further the links between science and industry'.

The Malvern Zetasizer Nano is used widely for the comprehensive characterisation of nano sized particles.

Its unique technology allows measurement of particle size, zeta potential and molecular weight in a single, easy to use system.

VISCOSITY
Viscosity if the measure of the liquid products resistance to flow. Kinematics viscosity is the ratio of the absolute viscosity to the specific gravity, usually expressed in centistokes (cs), where the resistance to flow is measured in square millimeters per second (mm2/s).

VISCOSITY EFFECTS ON RANGEABILITY
Viscosity has two different effects on the turbine flowmeter rotor. First of all, the profile causes boundary layer thickness to increase as viscosity increases for a fixed volume. This means that rotor-blade shape and length will be important in determining the K-factor since the flow around the blade tip region changes with respect to viscosity. This boundary layer thickness causes the turbine flowmeter to be non-linear. Supplying a shroud around the turbine rotor, with the shroud outer diameter slightly smaller than the inside diameter of the flow tube, increases the viscosity and creates a drag (resistance to rotation). This drag offsets the non-linear effect of the boundary layer.
The second effect of viscosity is one of viscous shear-force change on the rotor and increased viscous drag within the bearing. These effects act to slow the rotor while the profile effect acts to speed the rotor. The relative magnitude of all these forces changes the Reynolds number.
As previously indicated, some turbine flowmeter designs introduce a device or shroud that introduces viscous drag, which eliminates the hump that normally, occurs in the transition region.
While linearity is affected by viscosity, repeatability is not.

FLOW RANGE
The minimum flow rate of a turbine flowmeter becomes a factor of viscosity versus the degree of accuracy. As product viscosity increases, the minimum flow rate required to maintain a specific degree of accuracy increases. The maximum rate of flow allowable becomes a factor of viscosity versus the pressure drop across the flowmeter. As the product viscosity increases, the maximum flow rate decreases in accordance with the maximum allowable pressure drop across the flowmeter. In order to arrive at the minimum and maximum rate of flow limits for a particular turbine flowmeter size and application these factors must first be determined:
· The viscosity of the product to be metered (or maximum value of viscosity for products with varying viscosity's at 37.8B (100BF).
· The degree of accuracy required.
· The maximum amount of pressure drop allowed across the flowmeter.

Using an area-of-operation diagram for a particular turbine flowmeter size and charting the factors for viscosity accuracy and pressure drop will determine the minimum and maximum flow rates.

Operating the flowmeter within this flow range will meet the operating requirements unique to that application. Technical bulletins providing area of operation for turbine flowmeter sizes with varying viscosity fluids can be obtained from the various meter manufacturers.

CAVITATION
Cavitation in a turbine flowmeter will take place when the local pressures fall close to or below the vapor pressure of the liquid product. The formation of bubbles and their collapse or local vaporization of product as it passes over the rotor blade surface can cause erratic behavior in the turbine flowmeter and excessive wear due to over speeding. Maintaining a system backpressure of 2 times the flowmeter pressure drop plus 25 times the product vapor pressure is sufficient to prevent cavitation as shown by the following formula:

BP= (P x 2) + (VP x 1.25)

Where,
BP= Required back pressure
P= Pressure drop at maximum flow.
VP= Absolute vapor pressure at maximum temperature.

Cavitation usually causes the rotor to speed up at the high flow rate due to the increased flow volume and causes the accuracy curve of the turbine flowmeter to be adversely affected.

INSTALLATION
The term swirl is used to describe the rotational velocity or tangential velocity component of fluid flow in a pipe or tube. Depending on its degree and direction, swirl will change the angle of attack between the fluid and the turbine rotor blades, causing a different rotor speed at a constant flow rate to non-swirling conditions at the same flow rate. Liquid swirl and non-uniform velocity profiles may be introduced upstream of the turbine flowmeter by variations in piping configurations or projections and protrusions within the piping. Swirl may be effectively reduced or eliminated through the use of sufficient lengths of straight pipe or a combination of straight pipe and straightening vanes installed upstream of the turbine flowmeter.

APPLICATIONS
Turbine flowmeters, when first introduced, were used mainly by the aircraft industry in small sizes. Turbine flowmeters are now used on many applications (figure 3). Reasons for this increased used are sizes up to 12", weight and size versus flow rate, extended flow ranges, operating pressures up to 10,000 pounds per square inch, temperature range of -450° to 1000°F and a wide variety of construction materials including stainless steels.
In recent years, turbine flowmeters have been competing successfully with positive displacement flowmeters in many applications due to the economy of installation, low maintenance costs, weight, size and high flow rates per comparable connection size. You must exercise caution when making this comparison, especially on viscous products. Following the parameters outlined previously will prevent most misapplications of the turbine flowmeter.
When products are used in which viscosity changes with seasonal temperature, a proving run should be done at a time when the product temperature would be changing. For instance, fuel oil may change 50°F in ambient temperature between summer and winter. A change of this magnitude would affect the flowmeter curve and directly affect the flow range.
Increased expertise with electronics such as linearization is permitting turbine flowmeters to be used more widely (figure 4).


PROVING
Proving is a method of checking a measuring device against an accepted standard to determine the accuracy and repeatability of that measuring device. Turbine flowmeters should be proven immediately after installation, after repair, following removal from service (for any reason) when changing products, when product viscosity changes, or to chart the flow patterns of the flowmeter during a period of time.
In general, provings should be quite frequent in the early history of an installation. When sufficient results have been gathered to establish meter factor versus flow rate curves for each product, frequently proving can taper off unless one of the aforementioned reasons for proving occurs.

METHODS
There are several different methods of proving. Volumetric proving consists of a measured volume of fluid being compared to a known standard, such as a seraphin can or piston prover.
Gravimetric proving entails measuring weight of a fluid by scale or load cell, then converting it by a known formula.
Master-meter proving is the comparison of a test flowmeter to another flowmeter previously calibrated in one of the above methods.

CONCLUSION
Turbine flowmeters are becoming more prominent in the field of liquid flow measurement. Turbine flowmeter manufacturers continue to respond to industry interest with improvements.

The basic construction of the turbine flowmeter incorporates a bladed turbine rotor installed in a flow tube. The rotor is suspended axially in the direction of flow through the tube. The turbine flowmeter is a transducer, which senses the momentum of the flowing stream. The bladed rotor rotates on its axis in proportion to the rate of the liquid flow through the tube.

TURBINE ROTATION
As the liquid product strikes the front edge of the rotor blades, a low-pressure area is produced between the upstream cone and the rotor hub.
The blades of the turbine rotor will tend to travel toward this low-pressure area as a result of this pressure differential across the blades. The pressure differential (or pressure drop) constitutes the energy expended to produce movement of the rotor. The initial tendency of the rotor is to travel downstream in the form of axial thrust. But since the rotor is restrained from excessive downstream movement, the only resulting movement is rotation.
Fluid flowing through the meter impacts an angular velocity to the turbine rotor blades, which is directly proportional to the linear velocity of the liquid. The degree of the angular velocity or number of revolutions per minute of the turbine rotor is determined by the angle of the rotor blades to the flowing stream of the approach velocity.

ROTOR BALANCE
With axial thrust forcing the turbine rotor downstream, the friction resulting from contact between the turbine rotor and the downstream cone would cause excessive wear if there were not some means of balancing the turbine rotor on its axis between the upstream and the downstream cone.
Bernoulli's Principle states that when flow velocity decreases, the static pressure increases. Therefore, a high-pressure area exists at the downstream side of the turbine rotor exerting an upstream force on the rotor. As a result, the turbine rotor is hydraulically balanced on its axis.

SIGNAL OUTPUT
Electrical output is generated using the principle of reluctance. A pickup coil, wrapped around a permanent magnet, is installed on the exterior of the flow tube or the meter body immediately adjacent to the perimeter of the rotor (Figure 1). The magnet is the source of the magnetic flux field that cuts through the coil. Each blade of the turbine rotor passing in close proximity to the pickup coil causes a deflection in the existing magnetic field. This change in the reluctance of the magnetic circuit generates a voltage pulse within the pickup coil.
Each pulse generated represents a discrete amount of volumetric throughput. Dividing the total number of pulses generated by the specific amount of liquid product that passed through the turbine flowmeter determines the K-Factor. The K-Factor, expressed in pulses per unit volume, may be used with a factoring totalizer to provide an indication of volumetric throughput directly in engineering units. The totalizer continuously divides the incoming pulses by the K-Factor (or multiplies them with the inverse of the K-Factor) to provide factored totalization. The frequency of the pulse output, or number of pulses per unit time, is directly proportional to the rotational rate of the turbine rotor. Therefore, this frequency of the pulse output is proportional to the rate of the flow.

By dividing the pulse rate by the K-Factor, the volumetric throughput per unit time of the rate of flow can be determined. Frequency counters or converters are commonly used to provide instantaneous flow rate indication. Plotting the electrical signal output versus flow rate provides the characteristics profile or calibration curves for the turbine flowmeter.
Electrical output is also generated using the principle of inductance. A pickup coil is installed on the exterior of the flow tube immediately adjacent to the perimeter of the turbine rotor. The magnetic source of the flux field in this type of output is either the rotor itself or small magnets installed in the rotor. In the case of the rotor, the material of construction would be nickel or some other easily magnetized flux field. The results are identical to that of the reluctance principal.

ACCURACY
The accuracy of a turbine flowmeter is derived from its output (electrical or mechanical) and is the measure of the deviation of an indicated measurement from the referenced standard. Turbine meter accuracy is dependent upon several items.
The accuracy must include the error associated with the calibration standard. In the USA, the National Institute of Standards and Technology represents the flow standard.
Linearity is the variation of the flowmeter K-factor from a nominal value of a point on a curve. Normally during calibration, a value is chosen which makes linearity fall in line with accuracy. Linearity may remain constant during meter life although the absolute accuracy level has changed.
Repeatability is the ability of a turbine flowmeter to reproduce its output indefinitely under constant operating conditions at any point over its specified operating range.

SPECIFIC GRAVITY
The specific gravity of a liquid is the ratio of its density to that of water at 4BC (39.2BF) and is dimensionless. While changes in specific gravity do not affect the average turbine meter K-factor value, the overall linear range of the flowmeter is changed (Figure 2). The linear range represents the minimum to the maximum flow rate within which the linearity of the flowmeter is specified.
As stated previously, the rotor rotates due to pressure differential across the rotor blades. Specific gravity is one of the factors affecting this pressure differential. As the specific gravity decreases, the pressure differential decreases. On a fluid with a low specific gravity and a low flow rate, the pressure differential across the blades is very low. This leaves almost no energy for turning the rotor. Consequently, the rotor cannot turn in proportion to the liquid throughput and the K-factor drops off.

Therefore, the angle of the rotor blades is changed to help compensate for the change to a lower specific gravity. This allows products with lower specific gravity's to be measured accurately by the turbine flowmeter.