Exploitation of Vigorous Hydrothermal Systems

1982 ◽  
Vol 1 (3) ◽  
pp. 161-176
Author(s):  
John Elder
Keyword(s):  
Geothermal Energy ◽  
Theoretical Background ◽  
Hydrothermal Systems ◽  
Typical Development ◽  
Local Power ◽  
Energy Problem ◽  
Long Term Effects ◽  
Field Development ◽  
World Energy

Some 1% of the earth's crust has heat flux significantly above the global average. Concentrated in areas of the order of 10km2 associated with volcanic zones, such energy can be tapped for local power projects commonly generating 10MW km2. Such systems are of great value to those areas of developing countries, and elsewhere, lucky enough to possess this resource, but could never be seen as a ‘solution’ to the world energy problem. Long-term effects of field development are unknown, for instance development of the Wairakei field in New Zealand has only been active for 25 years. The vital choices for management of such fields are in how quickly energy is required, and how much. These choices will dertermine whether the resource must be ‘mined’ or whether it is possible to recharge the system and maintain a long-term supply. If the former, geothermal energy must be regarded as a ‘finite’ resource, for it is non-renewable, unless fluid extracted is replaced. Mining, resource definition, field development and theoretical background to these aspects are discussed and illustrated using a model of a typical development.

scholarly journals EVALUATION OF THE VOLUNTARY TAX COMPLIANCE IN SLOVENIA: TAX AUTHORITY PERSPECTIVE

2018 ◽  
pp. 153-169
Keyword(s):  
Tax Compliance ◽  
Pilot Project ◽  
Theoretical Background ◽  
Mutual Trust ◽  
Long Term Effects ◽  
Voluntary Compliance ◽  
The Status ◽  
Instrument Identification ◽  
Cooperative Relationship

Since 2015, certain taxpayers may apply for the special status in order to promote voluntary compliance at the Tax Authority of Republic of Slovenia (FURS), after the horizontal monitoring pilot project was successfully finished in 2010. The theoretical background of the status is based on the idea of co-operative compliance, which can be described as the monitoring, predicting and preventing problems in the tax authority and taxpayers relationship. The purpose of the section is to analyse the instrument, which should establish cooperation based on transparency, understanding and mutual trust between taxpayers and tax authority. The research methodology was focused on survey among tax experts participated in drafting the legislation implementing cooperative relationship as well as experts empowered for monitoring the institute. The main objectives of the study have focused on the current activities identification, the assessment of expectations, the gaps, constraints and potential changes of the instrument identification and the evaluation of the long-term effects of the institute.

scholarly journals The EGS Collab Project: An intermediate-scale field test to address enhanced geothermal system challenges

2020 ◽  
Vol 205 ◽  
pp. 01002
Author(s):  
Kneafsey Timothy ◽  
Keyword(s):  
Geothermal Energy ◽  
Crystalline Rock ◽  
Hydrothermal Systems ◽  
Heat Transfer Fluid ◽  
Geothermal System ◽  
Geothermal Systems ◽  
Geothermal Resources ◽  
Intermediate Scale ◽  
Term Extraction

Three components are typically needed to extract geothermal energy from the subsurface: 1. hot rock, 2. a heat transfer fluid, and 3. flow pathways contacting the fluid and the rock. These naturally occur in many locations resulting in hydrothermal systems, however there are enormous regions containing hot rock that do not naturally have adequate fluid, and/or appropriate fluid permeability to allow hot fluid extraction. Some type of engineering or enhancement of these systems would be required to extract the energy. These enormous regions provide the possibility of long-term extraction of significant quantities of energy. Enhanced (or engineered) Geothermal Systems (EGS) are engineered reservoirs created to extract economical amounts of heat from low permeability and/or porosity geothermal resources. There are technological challenges that must be addressed in order to extract the heat. These include proper stimulation, effective monitoring, reservoir control, and reservoir sustainability. The US DOE Geothermal Technologies Office and geothermal agencies from other countries have supported field tests over a range of scales and conditions. A current US field project, the EGS Collab Project, is working nearly a mile deep in crystalline rock at the Sanford Underground Research Facility (SURF) to study rock stimulation under EGS stress conditions. We are creating intermediate-scale (tens of meters) test beds via hydraulic stimulation and are circulating chilled water to model the injection of cooler water into a hot rock which would occur in an EGS, gathering high resolution data to constrain and validate thermal-hydrological-mechanical-chemical (THMC) modeling approaches. These validated approaches would then be used in the DOE’s flagship EGS field laboratory, Frontier Observatory for Research in Geothermal Energy (FORGE) underway in Milford, Utah and in commercial EGS. In the EGS Collab project, numerous stimulations have been performed, characterized, and simulated and long-term flow tests have been completed.

Ovarian Dysfunction in Fetally Irradiated Beagles

1977 ◽  
Vol 35 ◽  
pp. 658-659
Author(s):  
T. M. Seed ◽  
M. H. Sanderson ◽  
D. L. Gutzeit ◽  
T. E. Fritz ◽  
D. V. Tolle ◽  
...  
Keyword(s):  
Gamma Rays ◽  
Low Dose ◽  
Long Term Effects ◽  
Ovarian Dysfunction ◽  
Dose Rates ◽  
Highly Sensitive ◽  
Microscopic Evaluation ◽  
Ovarian Pathology ◽  
Normal Offspring

The developing mammalian fetus is thought to be highly sensitive to ionizing radiation. However, dose, dose-rate relationships are not well established, especially the long term effects of protracted, low-dose exposure. A previous report (1) has indicated that bred beagle bitches exposed to daily doses of 5 to 35 R 60Co gamma rays throughout gestation can produce viable, seemingly normal offspring. Puppies irradiated in utero are distinguishable from controls only by their smaller size, dental abnormalities, and, in adulthood, by their inability to bear young.We report here our preliminary microscopic evaluation of ovarian pathology in young pups continuously irradiated throughout gestation at daily (22 h/day) dose rates of either 0.4, 1.0, 2.5, or 5.0 R/day of gamma rays from an attenuated 60Co source. Pups from non-irradiated bitches served as controls. Experimental animals were evaluated clinically and hematologically (control + 5.0 R/day pups) at regular intervals.

Ultrastructural investigations of MDL 19,660-induced effects on the canine platelet and megakaryocyte

1990 ◽  
Vol 48 (3) ◽  
pp. 374-375
Author(s):  
D.E. Loudy ◽  
J. Sprinkle-Cavallo ◽  
J.T. Yarrington ◽  
F.Y. Thompson ◽  
J.P. Gibson
Keyword(s):  
Antidepressant Drug ◽  
Beagle Dogs ◽  
Long Term Effects ◽  
Short Term ◽  
Platelet Counts ◽  
Toxicological Studies ◽  
Induced Aggregation ◽  
Internal Architecture

Previous short term toxicological studies of one to two weeks duration have demonstrated that MDL 19,660 (5-(4-chlorophenyl)-2,4-dihydro-2,4-dimethyl-3Hl, 2,4-triazole-3-thione), an antidepressant drug, causes a dose-related thrombocytopenia in dogs. Platelet counts started to decline after two days of dosing with 30 mg/kg/day and continued to decrease to their lowest levels by 5-7 days. The loss in platelets was primarily of the small discoid subpopulation. In vitro studies have also indicated that MDL 19,660: does not spontaneously aggregate canine platelets and has moderate antiaggregating properties by inhibiting ADP-induced aggregation. The objectives of the present investigation of MDL 19,660 were to evaluate ultrastructurally long term effects on platelet internal architecture and changes in subpopulations of platelets and megakaryocytes.Nine male and nine female beagle dogs were divided equally into three groups and were administered orally 0, 15, or 30 mg/kg/day of MDL 19,660 for three months. Compared to a control platelet range of 353,000- 452,000/μl, a doserelated thrombocytopenia reached a maximum severity of an average of 135,000/μl for the 15 mg/kg/day dogs after two weeks and 81,000/μl for the 30 mg/kg/day dogs after one week.

Long-Term Effects of Head Lice Tx Unknown

2012 ◽  
Vol 43 (3) ◽  
pp. 42
Author(s):  
MITCHEL L. ZOLER
Keyword(s):  
Head Lice ◽  
Long Term Effects

The response of skin perfusion and of rheological and immunological variables to intravenous prostanoid administration in Raynaud’s phenomenon secondary to collagenosis

VASA ◽  
2005 ◽  
Vol 34 (4) ◽  
pp. 243-249 ◽  
Author(s):  
Drinda ◽  
Neumann ◽  
Pöhlmann ◽  
Vogelsang ◽  
Stein ◽  
...  
Keyword(s):  
Laser Doppler Flowmetry ◽  
Raynaud’S Phenomenon ◽  
Raynaud's Phenomenon ◽  
Plasma Viscosity ◽  
Laser Doppler ◽  
Erythrocyte Aggregation ◽  
Control Group ◽  
Long Term Effects ◽  
Doppler Flowmetry

Background: Prostanoids are used in the treatment of Raynaud’s phenomenon and acral perfusion disorders secondary to collagenosis. In subjective terms, intravenous administration of these agents produces success in more than 50% of patients. The therapeutic outcome of clinical administration of alprostadil or iloprost may vary from individual to individual. Patients and methods: The following variables were analysed in a cross-over study in 27 patients with collagenosis and Raynaud’s phenomenon: plasma viscosity and erythrocyte aggregation (rheological variables), partial pressure of oxygen and laser Doppler flowmetry in the finger region, and lymphocyte phenotyping and interleukin (IL) determinations (immunological variables). Results: Laser Doppler flowmetry revealed significant differences between patients with secondary Raynaud’s phenomenon and a control group of 25 healthy subjects. Laser Doppler readings did not change significantly as a result of the treatments. Therapy with iloprost produced a reduction in IL-1beta, L-selectin (CD 62 L) and IL-6. Conclusion: The change in immunological variables due to iloprost may explain the long-term effects of prostaglandins in the treatment of Raynaud’s phenomenon. From our results it is not possible to infer any preference for iloprost or alprostadil.

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