The benefits of building geothermal boilers in mine shafts in that, aside from their predictable energy production levels, they also function practically as an open tube system "but without any risk of heat contamination of aquifers".
Using geothermal energy also helps to reduce CO2 emissions, and is not dependent upon climatic conditions (unlike other renewable energies such as solar or wind power). Other advantages are that these facilities make use of a country's own resources, do not require new developments on large sites, do not pollute the immediate environment, and are believed to be profitable over the long term.
Geothermal energy can be used directly in family homes, housing developments, swimming pools, fish farms, industrial units and other buildings.
Friday, July 31, 2009
Mines could provide Geo thermal energy
When the mine is still active one can access the tunnels easily in order to gather data about ventilation and the properties of the rocks, as well as to take samples and design better circuits, and even programme the closure of some sections in order to use them for geothermal energy production", says the engineer, who stresses that, although geothermal energy can be made use of once the mine is closed, "it is no longer possible by that stage to make any modifications, or to gather any useful data to evaluate and improve the system".
The study looks into geothermal exploitation of a two-kilometre-long mine shaft, in which the temperature of the rocks 500m below the surface is around 30º C. This is typical of many of the mining areas in Asturias, although it could also be applied to other parts of the world. Water could be forced in through tubes at 7º C and return at 12º C, a big enough heat gain to be of benefit to towns located above the mines.
The study looks into geothermal exploitation of a two-kilometre-long mine shaft, in which the temperature of the rocks 500m below the surface is around 30º C. This is typical of many of the mining areas in Asturias, although it could also be applied to other parts of the world. Water could be forced in through tubes at 7º C and return at 12º C, a big enough heat gain to be of benefit to towns located above the mines.
Heart Failure: Women Different From Men; Absence Of Women In Clinical Trials Hinders Development Of Tailored Treatments
Current practice is to treat heart failure similarly in men and women," said Eileen Hsich, M.D., director of the Women's Heart Failure Clinic at the Cleveland Clinic in Ohio. "Yet, our reports suggests compelling sex differences, not only in terms of how and when heart failure develops, but also possible responses to treatments and how the disease impacts quality of life."
The data show that HF—a life-threatening condition in which the heart cannot pump enough blood throughout the body—affects women at an older age and often with a stronger heart compared to men. Hypertension and valvular disease are more likely the culprits for HF in women, whereas men are more likely to have coronary artery disease (CAD) as the underlying cause. And while women live longer with the disease, they also tend to have lower quality of life than men due to greater physical limitations with exercise, more HF-related hospital stays and depression.
"The reasons why survival is better for women remain unclear, but it may be due to differences in the underlying disease," said Dr. Hsich. "Our findings also raise questions as to whether certain diagnostic tests or criteria need to be changed to better reflect how HF presents in female versus male patients."
For example, "normal" values for brain natriuretic peptide—a biomarker that is being used more frequently to identify patients with symptoms of HF and stratify patients by risk—are higher for women versus men and abnormal values with a BNP > 500 pg/ml may be a stronger predictor of death in women with HF than in men. There is also evidence that sex-specific differences may result when performing a cardiopulmonary stress test, which is often used to evaluate patients for heart transplantation. Women with HF tend to have a better prognosis for any given peak oxygen consumption value when compared to men, yet the cut-off values to determine need for heart transplantation are the same for both sexes. The potential benefits of certain HF therapies both in terms of reducing morbidity and mortality appear to be different among women.
"We found that some of the available medications may not be as effective in women, while other therapies, for example, beta blockers, aldosterone antagonists and pacemakers, may be very beneficial," said Dr. Hsich, although she cautions that these finding should in no way prompt women to deviate from what their doctor recommends.
"We need to remember that the therapy women are receiving must be working because they are living longer," she added. "Still, we need to gain a better understanding of HF in women so that we know whether we are providing the best possible care."
A critical challenge remains enrolling women in clinical trials and inspiring researchers to conduct sex-specific studies.
"This is a disease that affects women just as much as men, yet it remains poorly understood and women are still underrepresented in studies," said Dr. Hsich, adding that major multicenter HF trials in the last decade on average only included 28 percent women. "It is really important for women to speak up and not wait for their doctor to approach them about participating in a clinical trial. In doing so, we can help ensure that future advances in HF treatments are applicable to women and supported by sound research."
Approximately 2.7 million women have HF, which accounts for 35 percent of the total female cardiovascular mortality.
The data show that HF—a life-threatening condition in which the heart cannot pump enough blood throughout the body—affects women at an older age and often with a stronger heart compared to men. Hypertension and valvular disease are more likely the culprits for HF in women, whereas men are more likely to have coronary artery disease (CAD) as the underlying cause. And while women live longer with the disease, they also tend to have lower quality of life than men due to greater physical limitations with exercise, more HF-related hospital stays and depression.
"The reasons why survival is better for women remain unclear, but it may be due to differences in the underlying disease," said Dr. Hsich. "Our findings also raise questions as to whether certain diagnostic tests or criteria need to be changed to better reflect how HF presents in female versus male patients."
For example, "normal" values for brain natriuretic peptide—a biomarker that is being used more frequently to identify patients with symptoms of HF and stratify patients by risk—are higher for women versus men and abnormal values with a BNP > 500 pg/ml may be a stronger predictor of death in women with HF than in men. There is also evidence that sex-specific differences may result when performing a cardiopulmonary stress test, which is often used to evaluate patients for heart transplantation. Women with HF tend to have a better prognosis for any given peak oxygen consumption value when compared to men, yet the cut-off values to determine need for heart transplantation are the same for both sexes. The potential benefits of certain HF therapies both in terms of reducing morbidity and mortality appear to be different among women.
"We found that some of the available medications may not be as effective in women, while other therapies, for example, beta blockers, aldosterone antagonists and pacemakers, may be very beneficial," said Dr. Hsich, although she cautions that these finding should in no way prompt women to deviate from what their doctor recommends.
"We need to remember that the therapy women are receiving must be working because they are living longer," she added. "Still, we need to gain a better understanding of HF in women so that we know whether we are providing the best possible care."
A critical challenge remains enrolling women in clinical trials and inspiring researchers to conduct sex-specific studies.
"This is a disease that affects women just as much as men, yet it remains poorly understood and women are still underrepresented in studies," said Dr. Hsich, adding that major multicenter HF trials in the last decade on average only included 28 percent women. "It is really important for women to speak up and not wait for their doctor to approach them about participating in a clinical trial. In doing so, we can help ensure that future advances in HF treatments are applicable to women and supported by sound research."
Approximately 2.7 million women have HF, which accounts for 35 percent of the total female cardiovascular mortality.
Quotient normed cones
1. Introduction and preliminaries
In recent years many works on functional analysis have been obtained in order to extend the well-known results of the classical theory of normed linear spaces to the framework of asymmetric normed linear spaces and quasi-normed cones. In particular, the dual of an asymmetric normed linear space has been constructed and studied in . In the same reference an asymmetric version of the celebrated Alouglu theorem has been proved . Several appropiate generalizations of the structure of the dual of an asymmetric normed linear space can be found .Hahn–Banach type theorems in the frame
of quasi-normed spaces have been given . The completion of asymmetric normed linear spaces and quasi-normed cones have been explored. An asymmetric version of the Riesz theorem for finite dimension linear spaces can be found . It seems interesting to point out that quasi-normed cones and other related ‘nonsymmetric’ structures from topological algebra and functional analysis, have been successfully applied, in the last few years, to several problems in theoretical computer science, approximation
theory and physics, respectively .
The purpose is to show that it is possible to generate in a natural way a quotient quasi-normed cone from a subcone of a given quasi-normed cone. Actually, we analyse when such quotient cones are bicomplete. We also construct and study the dual cone of a quasi-normed cone and we prove that it can be identified as the dual of a quotient cone. This is done with the help of an appropiate notion of a ‘polar’ cone.
In recent years many works on functional analysis have been obtained in order to extend the well-known results of the classical theory of normed linear spaces to the framework of asymmetric normed linear spaces and quasi-normed cones. In particular, the dual of an asymmetric normed linear space has been constructed and studied in . In the same reference an asymmetric version of the celebrated Alouglu theorem has been proved . Several appropiate generalizations of the structure of the dual of an asymmetric normed linear space can be found .Hahn–Banach type theorems in the frame
of quasi-normed spaces have been given . The completion of asymmetric normed linear spaces and quasi-normed cones have been explored. An asymmetric version of the Riesz theorem for finite dimension linear spaces can be found . It seems interesting to point out that quasi-normed cones and other related ‘nonsymmetric’ structures from topological algebra and functional analysis, have been successfully applied, in the last few years, to several problems in theoretical computer science, approximation
theory and physics, respectively .
The purpose is to show that it is possible to generate in a natural way a quotient quasi-normed cone from a subcone of a given quasi-normed cone. Actually, we analyse when such quotient cones are bicomplete. We also construct and study the dual cone of a quasi-normed cone and we prove that it can be identified as the dual of a quotient cone. This is done with the help of an appropiate notion of a ‘polar’ cone.
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