4 Used Jakob Muller Mbj3 Suppliers and Manufacturers

1. Current overload or line surge shutdown 2. High temperature compressor shutdown. 3. High pressure alarm shutdown. 4. Low pressure alarm shutdown. 5. Low oxygen cocentrator alarm. Oxygen concentrator: 0.5-5L/min Purity: 95%+_3% Working system Continuous Power Supply AC230V.50Hz/AC220V.60HZ AC120V.60Hz Power: 390VA Net Weight: 16kg( Gross weight: 18.5kgs) Warranty: Long-life compressor designed for 1000 hours of maintenance-free use. Size: 33*26*54cm

1.We use imported base paper from Germany. For solid color, base paper most 80 to 120GSM. For wood base paper is between 70-85 gsm 2. High quality water-base ink- Available over 200 shades in Solid colors and wood grains 3. With clear texture ,high Fidelity meeting international standards. 4. With smooth surface coating 5. Germproof, mould proof, antistatic and wear-resistance. 6. Green environmental protection and Odorlessness which Conforms to the GB18584-2001 standard requirement 7. Can be used for the hot press molding craft, the production efficiency is high. 8. Melamine paper takes shape easily, is widely used for the panel furniture and the decorative yarn. Product Specification: Width: 1230-1260mm or 1300-1800mm Length: 500-1000m For storing: Put it in room to a cool and dry place keep the temperature 20-25°C in room. The best humidity is: 50-60% We can also give you complete decorative solution with Matching Melamine Edge Banding, PU Paper. If you need just need Melamine/prelaminated boards either in MDF / Particle board we can also do so

Two tier Galvanized double deck bike rack/bicycle rack For all types of bicycles 2 tier bike rack can accommodate all types of bicycles, such as mountain bikes and town bikes, and any bicycles can also be chained for extra security. Once placed, the bicycle is well supported by wheel channels and the back wheel is stabilised by a gutter to lock the bicycle firmly. The lower rack has a sloping wheel channel, so the user does not have to bend between the levels which makes the cycle parking system simple and easy to use for all ages. This 2 tier bicycle rack is excellent for space saving as the cycle stands are compact with a centre to centre distance of around 370 mm. There is also the option to have the powder coated in any of the 192 RAL colours. Double deck bicycle rack features: 1.This double deck bicycle rack can park 2 bikes per set(one up, one down). 2.assembled in underground garage. 3.used for public place such as hosipital, school etc. 4.beautify the environment. 5.can Save space and prevention of theft.

Senna Plant Benefits For Health: As stated above, senna possesses medicinal value which can provide various health benefits given below. 1. Senna For Constipation: Being a laxative, senna is effective in relieving constipation. It has been approved by the US FDA as a non prescription drug to treat constipation. Senna stimulates the muscles of the colon to push fecal matter through more quickly. Senna leaf acts on the intestinal walls to cause contractions that lead to bowel movements. It softens stool by enabling the colon to absorb water. It can effectively cure even the most severe cases of constipation. The glycosides in it help transport electrolytes, causing bowel movements within 6 to 12 hours of its intake. Senna can be bought as an over the counter (OTC) medication for adults and children above 2 years of age.   2. Great Colon Cleanser: Senna has been regarded as a â??cleansing herbâ?? due to its laxative effects. Senna leaf is used in traditional Chinese medicine to clear away the heat accumulated in the large intestine, helping the body get rid of the stagnant food accumulated in the stomach. Today, it is widely used in cleansing the colon before colonoscopy and other types of colon surgery. 3. Treatment of Hemorrhoids: Senna has been found to be effective in the treatment of anal lacerations and hemorrhoids as it helps reduce swelling and facilitates quick healing. Moreover, since it promotes soft stools, it helps cause easy defecation in pathological conditions like anal fissure. This is due to the fact that after oral ingestion, the compounds in senna get absorbed into the intestinal tract, resulting in the separation of non-sugar parts in the colon. These non-sugar components increase the peristaltic movements by irritating and stimulating the intestinal tract. In this way, it speeds up the passage of stools through the intestinal tract. 4. Treatment of Intestinal Worms: The laxative properties of senna have been found to be useful in the treatment of worms in the stomach and colon.   Senna Medicinal Plant: Nutritional Value: The nutritional value of this herb has been explained in the table below. As evident from the table, it is devoid of calories and fat but a rich source of vitamin B

We supply high grade face veneer or core veneer. Wood species available: eucalyptus, acacia, poplar, keruing, okume, birch, pine etc. Our core veneer can be used for commercial grade plywood, film faced plywood, packing plywood. 1.Rotary cut : 1,270 x 640 x 1.0MM, OR 1.7mm 2.Sliced cut: 1270x Width 60mm upward , 0.45mm upwards 3.Thickness Tolerance: -0.03, + 0.05 4.Content Moisture: 18 % max 5.Drying process; Sundry or oven dry. 6.Cutting Process: Rotary Cutting/ Sliced cutting Grade A: 1. Full sheet of same color, no dead knot and small hole. No tear, No Joints 2. Whole piece (no joints) with live knots, limited dead knots, some small holes not more than 2cm in diameter. Also available in mix of grade A and B We can supply in following grade 1Grade A: 100% 2Grade A :90%+ Grade B:10% 3Grade B: 100%

1. When you just fill a pool of new water, it rains heavily suddenly, which makes you very depressed. Whether you still want to go on swimming. Swimming pool cover can keep out wind and rain and snow and ice for you,Any weather can not affect you enjoy into the water. 2.You are a swimming lover. Whether you particularly hope to extend your summer time. Swimming pool cover can expend your swimming season,you can enjoy the fun of useful under the transparent pool room which provided UV protection,Or you can directly open the swimming pool cover,Shared with family or friends at the water's edge which have health and comfortable swimming environment throughout the year. 3, UV resistant 50 microns UV resistant layer, let you skin not sunburn and peeling after swimming. 4.When you are making delicious food in your kitchen, your children may be ready to go swimming personal. Whether you want a special door to lock your swimming pool at that time, Limited the children close to the pool,prevent children or animals fell into the pool, The Whole family will be assured. 5.In order not to waste water, you are not willing to see worms and leaves in your swimming pool ! 6, constant temperature swimming No matter how cold in the winter, we can provide you with the pool heating equipment, keep your swimming pool constant temperature forever! Today, we offer you an amazing view in your garden---- a modern, comfortable and safe swimming pool roofing! Whether in front of your balcony or in the middle of your garden, the roofing can mix harmoniously together with surrounding environment without obstructing your view.

Juniper oil is used in aromatherapy to help stimulate and strengthen the nerves and bolster the spirits in challenging situations, while helping to relieve urine retention. It is used for treating rheumatism, arthritis and gout, as well as cellulite, acne, dermatitis, blocked pores, psoriasis and weeping eczemas. The main chemical components of juniper oil are a-pinene, camphene, b-pinene, sabinene, myrcene, a-phellandrene, a-terpinene, y-terpinene, 1,4-cineole, b-phellandrene, p-cymene, terpinen-4-ol, bornyl acetate, cayophyllene and trace amounts of limonene, camphor, linalool, linalyl acetate, borneol and nerol.

ROSE PEARLS is a GMO-free, natural product made of high-quality organic Rose Damascena oil from Bulgaria. Rose Damascena, also known to the world as the Oil giving Rose from Kazanlak, is the queen of flowers and the Rose valley in Bulgaria has become her kingdom. Our rose plantations are located in to the village of Skobelevo - in the heart of Bulgaria, an ecologically clean area at the foot of the Balkan Mountains. In order to extract the essential ingredients of roses, our company Alba Grups uses water-steam technology, a technology with tradition in distillation. We use no chemicals in our process. Hundreds of rose petals are needed to extract just one drop of rose oil. For a kilogram of rose oil we need about 4 tons of rose petals, nearly 1,660,000 freshly picked roses. Rose flowers are handpicked very early in the morning and are processed as fast as possible to keep the high quality of the oil. This makes it one of the most expensive essential oils in the world. Its quality, how it is used, and the way it benefits the body have been known to the world for centuries. Rose Pearls capsules are a food supplement and benefit the digestive and urinary system. They help strengthen and bring the bodies systems into harmony, including the respiratory, reproductive and immune systems. Only three pearls a day will make you feel healthy, alive and energetic.

Oregano - scientifically named Origanum vulgare by Carolus Linnaeus – is a common species of Origanum, a genus of the mint family (Lamiaceae). It is native to warm-temperate western and south western Eurasia and the Mediterranean region. Oregano is a perennial herb, growing from 20–80 cm tall, with opposite leaves 1- 4 cm long. The flowers are purple, 3–4 mm long, produced in erect spikes. It is sometimes called Wild Marjoram, and its close relative O. majoramum is then known as "Sweet Marjoram". Uses Culinary Dried oregano for culinary use. Oregano growing in a field. Oregano is an important culinary herb. It is particularly widely used in Turkish, Greek, Portuguese, Spanish, Latin American, and Italian cuisine. It is the leaves that are used in cooking, and the dried herb is often more flavourful than the fresh. [2] Oregano [3] is often used in tomato sauces, fried vegetables, and grilled meat. Together with basil, it contributes much to the distinctive character of many Italian dishes. It is commonly used by local chefs in southern Philippines when boiling carabao or cow meat to eliminate the odor of the meat, and to add a nice, spicy flavor. Oregano combines nicely with pickled olives, capers, and lovage leaves. Unlike most Italian herbs, [citation needed] oregano works with hot and spicy food, which is popular in southern Italy. Oregano is an indispensable ingredient in Greek cuisine. Oregano adds flavor to Greek salad and is usually added to the lemon-olive oil sauce that accompanies many fish or meat barbecues and some casseroles. In Turkish Cuisine, oregano is mostly used for flavoring meat, especially for mutton and lamb. In barbecue and kebab restaurants, it can be usually found on table, together with paprika, salt and pepper. Oregano growing in a pot. It has an aromatic, warm and slightly bitter taste. It varies in intensity; good quality oregano is so strong that it almost numbs the tongue, but the cultivars adapted to colder climates have often unsatisfactory flavor. The influence of climate, season and soil on the composition of the essential oil is greater than the difference between the various species. The related species Origanum onites (Greece, Turkey) and O. heracleoticum (Italy, Balkan Peninsula, West Asia) have similar flavors. A closely related plant is marjoram from Turkey, which, however, differs significantly in taste, because phenolic compounds are missing in its essential oil. Some breeds show a flavor intermediate between oregano and marjoram.

Sweet marjoram: Origanum (O) hortensis (orMajoranahortensis). Potmarjoram: O.onites Wildmajoram: O.vulgare. Syrian majoram is called zatar Family: Labiatae or Lamiaceae (mint family). In Europe, marjoram was a traditional symbol of youth and romantic love. Used by Romans as an aphrodisiac, it was used to cast love spells and was worn at weddings as a sign of happiness during the middle Ages. Greeks who wore marjoram wreaths at weddings called it “joy of the mountains.” It was used to brew beer before hops was discovered, and flavored a wine called hippocras. A cousin of the oregano family, marjoram originated in Mediterranean regions and is now a commonly used spice in many parts of Europe. Called zatar in the Middle east and often mistaken for oregano, it is also a popular spicing in Eastern Europe. Origin and Varieties Marjoram is indigenous to northern Africa and southwest Asia. It is cultivated around the Mediterranean, in England, Central and Eastern Europe, South America, the United States, and India. Description Marjoram leaf is used fresh, as whole or chopped, and dried whole or broken, and ground. The flowering tops and seeds, which are not as strong as the leaves, are also used as flavorings. Sweet marjoram is a small and oval-shaped leaf. It is light green with a greyish tint. Marjoram is fresh, spicy, bitter, and slightly pungent with camphor like notes. It has the fragrant herbaceous and delicate, sweet aroma of thyme and sweet basil. Pot marjoram is bitter and less sweet. Chemical Components Sweet marjoram has 0.3% to 1% essential oil, mostly monoterpenes. It is yellowish to dark greenish brown in color. It mainly consists of cis-sabinene hydrate (8% to 40%), -terpinene (10%), a-terpinene (7.6%), linalyl acetate (2.2%), terpinen 4-ol (18% to 48%), myrcene (1.0%), linalool (9% to 39%), -cymene (3.2%), caryophyllene (2.6%), and a-terpineol (7.6%). Its flavor varies widely depending on its origins. The Indian and Turkish sweet marjorams have more d-linalool, caryophyllene, carvacrol, and eugenol. Its oleoresin is dark green, and 2.5 lb. are equivalent to 100 lb. of freshly ground marjoram. Marjoram contains calcium, iron, magnesium, phosphorus, potassium, sodium, vitamin A, vitamin C, and niacin. Culinary uses of Marjoram Marjoram is typically used in European cooking and is added to fish sauces, clam chowder, butter-based sauces, salads, tomato-based sauces, vinegar, mushroom sauces, and eggplant. In Germany, marjoram is called the “sausage herb” and is used with thyme and other spices in different types of sausages. It is usually added at the end of cooking to retain its delicate flavor or as a garnish. It goes well with vegetables including cabbages, potatoes, and beans. The seeds are used to flavor confectionary and meat products.

Castor meal is also variously called castor meal, castor residue, castor extract & de-oiled castor cake Castor meal - the residue obtained from castor cake by the solvent extraction process - is one of the most versatile natural manures. It is truly organic manure which enhances the fertility of the soil without causing any damage or decay. It is enriched with the three big elements vital and conducive to the proper growth of crops - Nitrogen, Phosphorus and Potassium. It also has traces of nutrients like Manganese, Zinc and Copper, thus making it a balanced fertilizer. Moreover, it helps to neutralize the detrimental effects of chemical fertilizers. Apart from their contribution to Nutrients, they have a number of benefits in agriculture, which none of the synthetic fertilizers or pesticides can offer. They bring in the wonderful molecules that nature has designed to help the plants flourish naturally. They provide slow and steady nourishment, stimulation, protection from soil nematodes and insects; improve yields, and quality of product like taste, flavour, amino acid composition etc. The pressed cake obtained after the expression of castor bean. The solvent extracted cake, although rich in protein cannot be used as cattle fodder because of its toxicity. However, it can be used as a fertilizer. The protein content of castor seed meal varies from 21-48% depending upon the extent of decortications. It has an ideal amino acid profile with moderately high Cystine, mithionine, and isoleucine. But its ant nutritional substances, ricin, ricine and an allergen restrict its use in poultry feed, even at a very low level of inclusion. Castor Cake is an excellent fertilizer because of high content of N (6.4%), Phosphoric Acid (2.55%) and Potash (1%) and moisture retention. There is negative correlation between the contents of ricinine in castor seeds and oil content (r = -0.76). This content of ricinine in castor seed is determined by Agro climatic conditions. Nutrient content of Castor Cake: Organic matter - 75 - 80 %, Nitrogen - 4.0 - 4.5 %, Phosphorous - 1.5 %, Potassium - 1.25 - 1.5 %. It also contains some micro nutrients viz., Calcium, Magnesium, Sulphur, Iron, Zinc, Manganese, Copper etc. A typical composition of castor residue/meal is as follows: Nitrogen - 4% min. approx. Phosphorous - 1% min. approx. Potassium - 1% min. approx. Moisture - 10 - 12 % max. approx. Oil Content - 0.7% max. approx. Advantages: 1. It provides all the major & minor nutrients necessary for better plant growth. 2. It also helps in increasing the nutrient uptake by plants. 3. It improves the soil fertility and productivity. 4. It is known to protect the plants from nematodes and termites. 5. It improves the yield & quality of the farm produce. 6. It improves the physical, chemical and biological properties of soil

Turmeric is one of nature's most powerful healers. The active ingredient in turmeric is curcumin. Tumeric has been used for over 2500 years in India, where it was most likely first used as a dye. The medicinal properties of this spice have been slowly revealing themselves over the centuries. Long known for its anti-inflammatory properties, recent research has revealed that turmeric is a natural wonder, proving beneficial in the treatment of many different health conditions from cancer to Alzheimer's disease. Here are 20 reasons to add turmeric to your diet: 1. It is a natural antiseptic and antibacterial agent, useful in disinfecting cuts and burns. 2. When combined with cauliflower, it has shown to prevent prostate cancer and stop the growth of existing prostate cancer. 3. Prevented breast cancer from spreading to the lungs in mice. 4. May prevent melanoma and cause existing melanoma cells to commit suicide. 5. Reduces the risk of childhood leukemia. 6. Is a natural liver detoxifier. 7. May prevent and slow the progression of Alzheimer's disease by removing amyloyd plaque buildup in the brain. 8. May prevent metastases from occurring in many different forms of cancer. 9. It is a potent natural anti-inflammatory that works as well as many anti-inflammatory drugs but without the side effects. 10. Has shown promise in slowing the progression of multiple sclerosis in mice. 11. Is a natural painkiller and cox-2 inhibitor. 12. May aid in fat metabolism and help in weight management. 13. Has long been used in Chinese medicine as a treatment for depression. 14. Because of its anti-inflammatory properties, it is a natural treatment for arthritis and rheumatoid arthritis. 15. Boosts the effects of chemo drug paclitaxel and reduces its side effects. 16. Promising studies are underway on the effects of turmeric on pancreatic cancer. 17. Studies are ongoing in the positive effects of turmeric on multiple myeloma. 18. Has been shown to stop the growth of new blood vessels in tumors. 19. Speeds up wound healing and assists in remodeling of damaged skin. 20. May help in the treatment of psoriasis and other inflammatory skin conditions.

Rosemary (Rosmarinus officinalis) is a woody, perennial herb with fragrant evergreen needle-like leaves. It is native to the Mediterranean region. It is a member of the mint family Lamiaceae, which also includes many other herbs. The name rosemary derives from the Latin name rosmarinus, which is from "dew" (ros) and "sea" (marinus), or "dew of the sea" — apparently because it is frequently found growing near the sea. Description Forms range from upright to trailing; the upright forms can reach 1.5 m (5 ft) tall, rarely 2 m (6 ft 7 in). The leaves are evergreen, 2/4 cm (0.8/1.6 in) long and 2/5 mm broad, green above, and white below with dense short woolly hair. Flowering, very common in a mature and healthy specimen, blooms in summer in the north; but can be everblooming in warm-winter climates and is variable in color, being white, pink, purple, or blue. The rosemary plant is light blue and blooms from March to May. For most tonics and recipes the rosemary leaves are use more often than the flowers or the rest of the plant. Rosemary is a bushy type of evergreen that can grow six feet or higher. The tree contains leaves that are stiff and leathery.

Lotus Roots : 1. Heat and cool blood: Lotus root born with cold, with heat and cooling effect, can be used to treat hot disease; lotus root sweet and more liquid, fever thirst, Nvxue, hemoptysis, blood is particularly useful. 2. Laxative diarrhea, spleen appetizer: Lotus lotus contains mucin and dietary fiber, with the human body, the cholesterol and triglycerides in the human body, so that it is discharged from the feces, thereby reducing the absorption of lipids. Lotus root exudes a unique fragrance, but also contains tannins, there is a certain spleen diarrhea effect, can increase appetite, promote digestion, open stomach health, beneficial to poor appetite, loss of appetite were restored to health. 3. Yi Xue Sheng muscle: Lotus nutrient value is very high, rich in iron, calcium and other trace elements, plant protein, vitamins and starch content is also very rich, there are obvious tonic blood, enhance the role of human immunity. Therefore, Chinese medicine called it: "the main fill in the spirit of God. 4. Hemostasis stasis: Lotus root contains a lot of tannic acid, a contraction of blood vessels, can be used to stop bleeding. Lotus can also cooling blood, blood, Chinese medicine that hemostasis without leaving stasis, is the disease of hyperthermia diet to share.

Melon Seeds : Nutritional value - 1. Sunflower seeds are rich in unsaturated fatty acids, high quality protein, potassium, phosphorus, calcium, magnesium, selenium and vitamins E, vitamin B1 and other nutrients 2. It contains a wealth of potassium on the heart has a protective function, to prevent a lot of benefits of hypertension 3. Sunflower seeds are rich in vitamin E, to prevent aging, improve immunity, the role of prevention of cardiovascular disease 4. Sunflower seeds contained in the plant sterols and phospholipids, can inhibit the synthesis of cholesterol in the human body to prevent excessive plasma cholesterol, to prevent atherosclerosis 5. Sunflower seeds also regulate brain cell metabolism, improve its role in inhibiting the function, it can be used for hypnosis

Hazelnut : Application of hazelnut - 1, in the field of food, hazelnut can be made of single food can also be made of sticky chocolate, candy, pastry and other processed foods. 2, hazelnut oil is about 54% of soybeans 2 to 3 times, is squeezed edible oil and a variety of industrial oil raw materials, oil can be used as feed or fertilizer. 3, stick can also be medicine. Hazelnut is rich in unsaturated fatty acids, with lower cholesterol, effectively prevent the occurrence of cardiovascular and cerebrovascular disease; hazelnut in the vitamin E content of up to 36%, with anti-aging, cure blood vessels hardening, moisturizing the skin , The stick contains anti-cancer chemical ingredients paclitaxel, can treat ovarian cancer and breast cancer and some other cancer, can extend the patient's life; stick in the magnesium, calcium and potassium and other trace elements in the high content of long-term food help To adjust blood pressure. 4, hazelnut shell is the production of shells activated carbon raw materials. Hazelnut can be sericulture.

Orange : Orange color is bright, sweet and sour, generally orange, is one of the most common fruit in people's life, peel can be used as medicine. Orange sweet acid, warm, into the lungs. The main treatment of chest stagnation, vomiting, Eat less, stomach yin deficiency, mouth thirst, Hyperactivity cough and excessive drinking. With appetizers, thirst quencher lungs effect. Orange nutrition is also very rich, an orange almost every day to meet the human body needs vitamin C content. And the orange contains more than 170 kinds of plant compounds and more than 60 kinds of flavonoids, most of which are natural antioxidants. Organs rich in nutrients are hypolipidemic, anti-atherosclerosis and other effects, the prevention of cardiovascular disease in the great benefit. Juice contains a substance called "Norlylin", with the ability to inhibit and kill cancer cells, the prevention of gastric cancer. Orange peel was orange-red, flesh was granular, and grapefruit is very similar. Orange peel thin meat, juicy sweet and sour, peeled orange orange water can overflow. Citrus fruit nutrient-rich, color and flavor and excellent, both fresh, but also processed into a variety of fruit juice-based processing products. Citrus production is the first of the fruit, citrus juice accounted for 3/4 of the juice, widely favored by consumers. According to the Central Health Research Institute, citrus per 100 grams of edible parts, containing 0.05 mg of riboflavin, 0.3 mg of niacin, 16 mg of ascorbic acid (vitamin C), 0.9 g of protein, 0.1 g of fat, 12 g of sugar, 0.2 grams of fiber, 0.4 grams of inorganic salts, 26 mg of calcium, 15 mg of phosphorus, 0.2 milligrams of iron, and 221.9 joules of calories. Orange carotene (vitamin A original) content after apricot, higher than other fruits.

Kiwi : The world's largest consumption of the first 26 kinds of fruit, kiwi is the most comprehensive. The content of Vc, Mg and trace elements in kiwifruit fruit was the highest. Among the top three low-sodium and high-potassium fruits, kiwi is at the top of the list because it contains more potassium than bananas and citrus. At the same time, the content of Ve and Vk in kiwifruit was determined to be excellent, low in fat and no cholesterol. According to the analysis, kiwi fruit vitamin content per 100 grams of fresh samples in general 100-200 mg, high up to 400 mg, about 5-10 times the citrus; sugar 8-14%, acid 1.4-2- 0%, but also with tyrosine and other amino acids 12 species. kiwi fruit contains a wide range of nutrients, most of the fruit is rich in one or two nutrients, but each kiwi can provide 8% DV folic acid, 8% DV copper, 8% pantothenic acid, 6% Fresh, 4% DV iron and vitamin B6, 2% DV phosphorus and Va as well as other vitamins and minerals. Kiwi in addition to kiwi alkali, proteolytic enzymes, tannin pectin and sugar and other organic matter, as well as calcium, potassium, selenium, zinc, germanium and other trace elements and the human body needs 17 kinds of amino acids, but also rich in vitamins, , Fructose, citric acid, malic acid, fat. A kiwi can provide a day more than twice the demand for vitamin C, known as the "king of fruit." Kiwi also contains good soluble dietary fiber, as the fruit of the most eye-catching place is contained in its superior antioxidant properties of plant chemical substances sod, according to the US Department of Agriculture research report, kiwi comprehensive antioxidant index in the Fruits among the top, second only to the thorns, blueberries and other small fruit, far stronger than apples, pears, watermelon, citrus and other daily fruits. And blueberries belong to the second generation of fruit is quite representative. Compared with sweet orange and lemon, kiwi fruit contains vitamin C ingredients are two times the first two fruits, so often used to fight against scurvy. Not only that, kiwi can stabilize mood, lower cholesterol, help digestion, prevent constipation, as well as thirst and diuretic and protect the role of the heart.