The genus of the myrrhs, Commiphora, is the most species-rich genus of flowering plants in the frankincense and myrrh family, Burseraceae. The genus contains 190 species of shrubs and trees, which are distributed throughout the tropical regions of Africa, the western Indian Ocean islands, the Arabian Peninsula and Vietnam; the genus is drought-tolerant and common throughout the xerophytic scrub, seasonally dry tropical forests, woodlands of these regions. The common name myrrh refers to several species of the genus, from which aromatic resins are derived for various fragrance and medicinal uses by humans. Leaves in Commiphora are pinnately compound. Many species are armed with spines. Bark is exfoliating, peeling in thin sheets to reveal colorful, sometimes photosynthetic bark, below. Stems are succulent in species native to drier environments. Flowers are subdioecious and fruits are drupes with a 2-locular ovary. In response to wounding, the stems of many species will exude aromatic resins. Commiphora can serve as a model genus for understanding plant evolution in the drier regions of the Old World tropics in eastern continental Africa and Madagascar, where diversity in the genus is concentrated.
The related sister genus to Commiphora, has been used as a model genus to study patterns of evolution in the New World seasonally dry tropical forests. Products from many species of Commiphora have been used for various purposes, sometimes as timber, building material, natural fencing, but more valued for the aromatic resins produced by several members of the genus. "Myrrh", the common name for these dried resins, is fragrant and has been used both as fragrance and for medicinal purposes. Use of myrrh resin is frequent and pronounced throughout historical texts of cultural significance, including the Bible. Recent studies using DNA sequence data have confirmed the monophyly of Commiphora. Species include: Commiphora africana Engl. sometimes identified with ancient bdellium. Used indirectly by the San bushmen to poison their arrow tips for hunting Commiphora angolensis Engl. known as "sand commiphora", growing in Angola and Namibia Commiphora boranensis Vollesen Commiphora caudata Engl. Commiphora corrugata J.
B. Gillett & Vollesen Commiphora erythraea Engl, modern source of opopanax Commiphora gileadensis C. Chr. Producing balsam of Mecca. Commiphora glandulosa Schinz Commiphora guidottii Chiov. Ex Guid. Producing scented habak hadi in Somali. Commiphora guillauminii H. Perrier Commiphora habessinica Engl. Commiphora harveyi Engl. Commiphora holtziana Engl. Commiphora humbertii H. Perrier Commiphora kataf Engl. used in producing bisabol. Commiphora madagascariensis Jacq. Commiphora mossambicensis Engl. Commiphora myrrha Engl. Producing myrrh. Commiphora saxicola Engl. Rock corkwood, a shrub endemic to Namibia Commiphora schimperi Engl. Commiphora simplicifolia H. Perrier Commiphora sphaerocarpa Chiov Commiphora stocksiana Engl. Known in Pakistan as bayisa gugal Commiphora wightii Bhandari, producing gum guggul, sometimes identified with ancient bdellium. Flora of Pakistan: Commiphora Biblical Burseraceae
Wood ash is the residue powder left after the combustion of wood, such as burning wood in a home fireplace or an industrial power plant. It is used traditionally by gardeners as a good source of potash. Many studies have been conducted regarding the chemical composition of wood ash, with varying results; some quote calcium carbonate as the major constituent, others find no carbonate at all, but calcium oxide instead. Some show as much as twelve percent iron oxide while others show none, though iron oxide is introduced through contamination with soil. A comprehensive set of analyses of wood ash composition from many tree species has been carried out by Emil Wolff, among others. Several factors have a major impact on the composition: Fly ash: Some studies include the solids escaping via the flue during combustion, while others do not. Temperature of combustion produces two direct effects: Dissociation: Conversion of carbonates, etc. to oxides results in no carbon, carbonates, or sulfides. Some metallic oxides dissociate to their elemental state and/or vaporize at wood fire temperatures.
Volatilization: In studies in which the fly ash is not measured, some combustion products may not be present at all. Experimental process: If the ashes are exposed to the environment between combustion and the analysis, oxides may convert back to carbonates by reacting with carbon dioxide in the air. Type and growing environment of the wood stock affect the composition of the wood, thus the ash. Between 0.43 and 1.82 percent of the mass of burned wood results in ash. The conditions of the combustion affect the composition and amount of the residue ash, thus higher temperature will reduce ash yield. Much wood ash contains calcium carbonate as its major component, representing 25 or 45 percent. Less than 10 percent is potash, less than 1 percent phosphate. However, these numbers vary, as combustion temperature is an important variable in determining wood ash composition. All of these are in the form of oxides. Wood ash can be used as an organic fertilizer used to enrich agricultural soil nutrition.
In this role, wood ash serves a source of potassium and calcium carbonate, the latter acting as a liming agent to neutralize acidic soils. Wood ash can be used as an amendment for organic hydroponic solutions replacing inorganic compounds containing calcium, potassium and phosphorus. Wood ash is disposed of in landfills, but with rising disposal costs, ecologically friendly alternatives, such as serving as compost for agricultural and forestry applications, are becoming more popular; because wood ash has a high char content, it can be used as an odor control agent in composting operations. Wood ash has a long history of being used in ceramic glazes in the Chinese and Korean traditions, though now used by many craft potters, it acts as a flux. Potassium hydroxide can be made directly from wood ash and in this form, is known as caustic potash or lye; because of this property, wood ash has traditionally been used to make wood-ash soap. The ectomycorrhizal fungi Suillus granulatus and Paxillus involutus can release elements from wood ash.
Ash burner Bottom ash Charcoal Fly ash Potash
A desert is a barren area of landscape where little precipitation occurs and living conditions are hostile for plant and animal life. The lack of vegetation exposes the unprotected surface of the ground to the processes of denudation. About one-third of the land surface of the world is semi-arid; this includes much of the polar regions where little precipitation occurs and which are sometimes called polar deserts or "cold deserts". Deserts can be classified by the amount of precipitation that falls, by the temperature that prevails, by the causes of desertification or by their geographical location. Deserts are formed by weathering processes as large variations in temperature between day and night put strains on the rocks which break in pieces. Although rain occurs in deserts, there are occasional downpours that can result in flash floods. Rain falling on hot rocks can cause them to shatter and the resulting fragments and rubble strewn over the desert floor are further eroded by the wind; this wafts them aloft in sand or dust storms.
Wind-blown sand grains striking any solid object in their path can abrade the surface. Rocks are smoothed down, the wind sorts sand into uniform deposits; the grains are piled high in billowing sand dunes. Other deserts are flat, stony plains where all the fine material has been blown away and the surface consists of a mosaic of smooth stones; these areas are known as desert pavements and little further erosion takes place. Other desert features include rock outcrops, exposed bedrock and clays once deposited by flowing water. Temporary lakes may form and salt pans may be left when waters evaporate. There may be underground sources of water in the form of seepages from aquifers. Where these are found, oases can occur. Plants and animals living in the desert need special adaptations to survive in the harsh environment. Plants tend to be tough and wiry with small or no leaves, water-resistant cuticles and spines to deter herbivory; some annual plants germinate and die in the course of a few weeks after rainfall while other long-lived plants survive for years and have deep root systems able to tap underground moisture.
Animals need to find enough food and water to survive. Many stay in the shade or underground during the heat of the day, they tend to be efficient at conserving water, extracting most of their needs from their food and concentrating their urine. Some animals remain in a state of dormancy for long periods, ready to become active again during the rare rainfall, they reproduce while conditions are favorable before returning to dormancy. People have struggled to live in the surrounding semi-arid lands for millennia. Nomads have moved their flocks and herds to wherever grazing is available and oases have provided opportunities for a more settled way of life; the cultivation of semi-arid regions encourages erosion of soil and is one of the causes of increased desertification. Desert farming is possible with the aid of irrigation, the Imperial Valley in California provides an example of how barren land can be made productive by the import of water from an outside source. Many trade routes have been forged across deserts across the Sahara Desert, traditionally were used by caravans of camels carrying salt, gold and other goods.
Large numbers of slaves were taken northwards across the Sahara. Some mineral extraction takes place in deserts, the uninterrupted sunlight gives potential for the capture of large quantities of solar energy. English desert and its Romance cognates all come from the ecclesiastical Latin dēsertum, a participle of dēserere, "to abandon"; the correlation between aridity and sparse population is complex and dynamic, varying by culture and technologies. In English before the 20th century, desert was used in the sense of "unpopulated area", without specific reference to aridity. Phrases such as "desert island" and "Great American Desert", or Shakespeare's "deserts of Bohemia" in previous centuries did not imply sand or aridity. A desert is a region of land, dry because it receives low amounts of precipitation has little coverage by plants, in which streams dry up unless they are supplied by water from outside the area. Deserts receive less than 250 mm of precipitation each year; the potential evapotranspiration may be large but the actual evapotranspiration may be close to zero.
Semideserts are regions which receive between 250 and 500 mm and when clad in grass, these are known as steppes. Deserts have been defined and classified in a number of ways combining total precipitation, number of days on which this falls and humidity, sometimes additional factors. For example, Arizona, receives less than 250 mm of precipitation per year, is recognized as being located in a desert because of its aridity-adapted plants; the North Slope of Alaska's Brooks Range receives less than 250 mm of precipitation per year and is classified as a cold desert. Other regions of the world have cold deserts, including areas of the Himalayas and other high-altitude areas in other parts of the world. Polar deserts cover much of the ice-free
Water scarcity is the lack of fresh water resources to meet water demand. It affects every continent and was listed in 2019 by the World Economic Forum as one of the largest global risks in terms of potential impact over the next decade, it is manifested by partial or no satisfaction of expressed demand, economic competition for water quantity or quality, disputes between users, irreversible depletion of groundwater, negative impacts on the environment. One-third of the global population live under conditions of severe water scarcity at least 1 month of the year. Half a billion people in the world face severe water scarcity all year round. Half of the world’s largest cities experience water scarcity. A mere 0.014% of all water on Earth is both fresh and accessible. Of the remaining water, 97 % is a little less than 3 % is hard to access. Technically, there is a sufficient amount of freshwater on a global scale. However, due to unequal distribution resulting in some wet and some dry geographic locations, plus a sharp rise in global freshwater demand in recent decades driven by industry, humanity is facing a water crisis.
Demand is expected to outstrip supply by 40 % in 2030. The essence of global water scarcity is the geographic and temporal mismatch between freshwater demand and availability; the increasing world population, improving living standards, changing consumption patterns, expansion of irrigated agriculture are the main driving forces for the rising global demand for water. Climate change, such as altered weather-patterns, increased pollution, green house gases, wasteful use of water can cause insufficient supply. At the global level and on an annual basis, enough freshwater is available to meet such demand, but spatial and temporal variations of water demand and availability are large, leading to water scarcity in several parts of the world during specific times of the year. All causes of water scarcity are related to human interference with the water cycle. Scarcity varies over time as a result of natural hydrological variability, but varies more so as a function of prevailing economic policy and management approaches.
Scarcity can be expected to intensify with most forms of economic development, but, if identified, many of its causes can be predicted, avoided or mitigated. Some countries have proven that decoupling water use from economic growth is possible. For example, in Australia, water consumption declined by 40% between 2001 and 2009 while the economy grew by more than 30%; the International Resource Panel of the UN states that governments have tended to invest in inefficient solutions: mega-projects like dams, aqueducts and water reservoirs, which are neither environmentally sustainable nor economically viable. The most cost-effective way of decoupling water use from economic growth, according to the scientific panel, is for governments to create holistic water management plans that take into account the entire water cycle: from source to distribution, economic use, recycling and return to the environment; the total amount of accessible freshwater on Earth, in the form of surface water or groundwater, is 14.000 cubic kilometres.
Of this total amount, ` just' 5.000 cubic kilometres are being reused by humanity. Hence, in theory, there is more than enough freshwater available to meet the demands of the current world population of more than 7 billion people, support population growth to 9 billion or more. Due to the unequal geographical distribution and the unequal consumption of water, however, it is a scarce resource in some parts of the world and for some parts of the population. Scarcity as a result of consumption is caused by the extensive use of water in agriculture/livestock breeding and industry. People in developed countries use about 10 times more water daily than those in developing countries. A large part of this is indirect use in water-intensive agricultural and industrial production processes of consumer goods, such as fruit, oil seed crops and cotton; because many of these production chains have been globalised, a lot of water in developing countries is being used and polluted in order to produce goods destined for consumption in developed countries.
Water scarcity can result from two mechanisms: physical water scarcity economic water scarcityPhysical water scarcity results from inadequate natural water resources to supply a region's demand, economic water scarcity results from poor management of the sufficient available water resources. According to the United Nations Development Programme, the latter is found more to be the cause of countries or regions experiencing water scarcity, as most countries or regions have enough water to meet household, industrial and environmental needs, but lack the means to provide it in an accessible manner. Around one fifth of the world's population live in regions affected by Physical water scarcity, where there is inadequate water resources to meet a country's or regional demand, including the water needed to fulfill the demand of ecosystems to function effectively. Arid regions suffer from physical water scarcity, it occurs where water seems abundant but where resources are over-committed, such as when there is over development of hydraulic infrastructure for irrigation.
Symptoms of physical water scarcity include environmental degradation and declining groundwater as well as other forms of exploitation or overuse. Economic water scarcity is caused by a lack of investment in
Namibia the Republic of Namibia, is a country in southern Africa. Its western border is the Atlantic Ocean. Although it does not border Zimbabwe, less than 200 metres of the Zambezi River separates the two countries. Namibia gained independence from South Africa on 21 March 1990, following the Namibian War of Independence, its capital and largest city is Windhoek, it is a member state of the United Nations, the Southern African Development Community, the African Union, the Commonwealth of Nations. Namibia, the driest country in Sub-Saharan Africa, was inhabited since early times by the San and Nama peoples. Around the 14th century, immigrating Bantu peoples arrived as part of the Bantu expansion. Since the Bantu groups, the largest being the Ovambo, have dominated the population of the country. In 1878, the Cape of Good Hope a British colony, had annexed the port of Walvis Bay and the offshore Penguin Islands. In 1884 the German Empire established rule over most of the territory as a protectorate.
It began to develop infrastructure and farming and maintained this German colony until 1915, when South African forces defeated its military. In 1920, after the end of World War I, the League of Nations mandated the country to the United Kingdom, under administration by South Africa, it imposed its laws, including racial rules. From 1948, with the National Party elected to power, South Africa applied apartheid to what was known as South West Africa. In the 20th century and demands for political representation by native African political activists seeking independence resulted in the UN assuming direct responsibility over the territory in 1966, but South Africa maintained de facto rule. In 1973 the UN recognised the South West Africa People's Organisation as the official representative of the Namibian people. Following continued guerrilla warfare, South Africa installed an interim administration in Namibia in 1985. Namibia obtained full independence from South Africa in 1990. However, Walvis Bay and the Penguin Islands remained under South African control until 1994.
Namibia has a population of a stable multi-party parliamentary democracy. Agriculture, herding and the mining industry – including mining for gem diamonds, gold and base metals – form the basis of its economy; the large, arid Namib Desert has resulted in Namibia being overall one of the least densely populated countries in the world. The name of the country is derived from the Namib Desert, considered to be the oldest desert in the world; the name Namib itself is of Nama origin and means "vast place". Before its independence in 1990, the area was known first as German South-West Africa as South-West Africa, reflecting the colonial occupation by the Germans and the South Africans; the dry lands of Namibia have been inhabited since early times by San and Nama. Around the 14th century, immigrating Bantu people began to arrive during the Bantu expansion from central Africa. From the late 18th century onward, Oorlam people from Cape Colony crossed the Orange River and moved into the area that today is southern Namibia.
Their encounters with the nomadic Nama tribes were peaceful. They received the missionaries accompanying the Oorlam well, granting them the right to use waterholes and grazing against an annual payment. On their way further north, the Oorlam encountered clans of the Herero at Windhoek and Okahandja, who resisted their encroachment; the Nama-Herero War broke out in 1880, with hostilities ebbing only after the German Empire deployed troops to the contested places and cemented the status quo among the Nama and Herero. The first Europeans to disembark and explore the region were the Portuguese navigators Diogo Cão in 1485 and Bartolomeu Dias in 1486, but the Portuguese did not try to claim the area. Like most of interior Sub-Saharan Africa, Namibia was not extensively explored by Europeans until the 19th century. At that time traders and settlers came principally from Sweden. In the late 19th century, Dorsland Trekkers crossed the area on their way from the Transvaal to Angola; some of them settled in Namibia instead of continuing their journey.
Namibia became a German colony in 1884 under Otto von Bismarck to forestall perceived British encroachment and was known as German South West Africa. The Palgrave Commission by the British governor in Cape Town determined that only the natural deep-water harbor of Walvis Bay was worth occupying and thus annexed it to the Cape province of British South Africa. From 1904 to 1907, the Herero and the Namaqua took up arms against brutal German colonialism. In calculated punitive action by the German occupiers, government officials ordered extinction of the natives in the Herero and Namaqua genocide. In what has been called the "first genocide of the 20th century", the Germans systematically killed 10,000 Nama and 65,000 Herero; the survivors, when released from detention, were subjected to a policy of dispossession, forced labor, racial segregation, and
Butterfat or milkfat is the fatty portion of milk. Milk and cream are sold according to the amount of butterfat they contain; the fatty acids of butterfat are composed as follows: As shown above, the composition of fats in milk is discussed in terms of the fatty acids. Fatty acids do not occur as such in milk. Instead, they are incorporated into compounds called triglycerides. In the U. S. there are federal standards for butterfat content of dairy products. Many other countries have standards for minimum fat levels in dairy products. Commercial products contain the minimum legal amount of fat with any excess being removed to make cream, a valuable commodity. Milks Skim milk contains less than 0.5% fat 0.1% Lowfat milk contains between 0.5–2% fat.