Intracranial aneurysm, a localized dilation of arterial blood vessels in the Circle of Willis and its branches, is potentially life threatening, due to massive bleeding in the subarachnoid space upon rupture. In clini...Intracranial aneurysm, a localized dilation of arterial blood vessels in the Circle of Willis and its branches, is potentially life threatening, due to massive bleeding in the subarachnoid space upon rupture. In clinical practice, one minimally invasive surgical procedure is the implantation of a metallic stent to cover the aneurysm neck. This flow diverting device can reduce the flow into the aneurysm and enhance the prospect of thrombosis, a condition expected to reduce the risk of growth and rupture. The biomechanical and haemo-dynamic factors in stented and nonstented situations are studied by computational fluid dynamics. Unlike earlier models with straight or curved parent blood vessels, the aneurysm is now located near an arterial bifurcation. The influence of the aspect (depth to neck) ratio of the aneurysm on the flow dynamics will be emphasized, especially in the post-operation stages. More precisely, the maximum flow velocity, the variations of wall shear stress, the risk of stent migration and volumetric flow rate after endovascular treatment will be studied. Aneurysms with larger aspect ratios (i.e. smaller neck sizes for constant depth) generally pose a greater risk in terms of these flow parameters. These results will assist the applications and design of stents in future neurosurgical therapy. The approach is limited to a nonelastic model, without taking into account of questions like stent expansion and interaction with tissue.展开更多
The diurnal and semidiurnal tidal wind field variations in the altitudes between 80 and 100 km of the earth's atmosphere over a mid-latitude station are studied by means of the phases of the zonal and meridional w...The diurnal and semidiurnal tidal wind field variations in the altitudes between 80 and 100 km of the earth's atmosphere over a mid-latitude station are studied by means of the phases of the zonal and meridional wind measurements made at Atlanta (34 ° N, 84 ° W). The rotation of diurnal tidal wind vector is seen to be clockwise at lower heights (80-86 km), swinging between clockwise and anti-clockwise at intermediate heights (88-96 km) and anti-clockwise at higher heights (96-100 km). The senses of rotation of diurnal and semidiurnal tidal wind vectors are compared between the stations located in the same and opposite hemispheres. The results are consistent with the tidal theory in the case of Atlanta and Adelaide (35°S, 139 ° E) whereas in the case of other stations considered in the present study, they showed marked variations.展开更多
Small wastewater treatment plants (WWTP) are frequently located, by necessity, in remote and isolated sites, which increases the difficulty of its energy supply. Some of them are located near the seaside, in environme...Small wastewater treatment plants (WWTP) are frequently located, by necessity, in remote and isolated sites, which increases the difficulty of its energy supply. Some of them are located near the seaside, in environmental sensible zones, and due to tourism activity of these sites, seasonal effects related with population size fluctuation can occur, which can originate certain inefficiencies concerning WWTP design and energy supply. The objective of this paper is to describe a step by step procedure for evaluation of the wind potential of sites that are dependent of in-situ energy generation, as well as, a case study on the utilization of the potential wind energy in Magoito WWTP (5000 p.e.). The employed methodology comprised the collection of one year of in-situ wind data and its validation by comparison with historical data of about 10 years of a nearby anemometric station. The data provided by the two anemometric stations was statistically treated. It allowed the analysis of the results from the two stations are promissory in terms of wind availability and velocity. Finally, it comprised the simulation of the local wind conditions for a considerable larger area in order to find the best site for locating a wind turbine.展开更多
About 1.1 million people are estimated to have age-related macular degeneration in West Germany. Anatomical aspects of the normal macula and physiological ageing processes in the retina will be discribed including alt...About 1.1 million people are estimated to have age-related macular degeneration in West Germany. Anatomical aspects of the normal macula and physiological ageing processes in the retina will be discribed including alterations in the choroid, in Bruch's membrane, the pigment epithelium and the sensory retina. Risk factors for the development of age-related macular degeneration are age per se, perhaps ethnologic characteristics, ocular characteristics, and perhaps environmental factors. The histopathology...展开更多
The theory of"all winds and dizziness belong to the liver"provides a basis for 1ater plysicians to study the etiologic and pathogenesis of vertigo diseases.This theory of pathogenesis suggests that vertigo d...The theory of"all winds and dizziness belong to the liver"provides a basis for 1ater plysicians to study the etiologic and pathogenesis of vertigo diseases.This theory of pathogenesis suggests that vertigo diseases are most closely related to the liver,so the mechanism can be simply understood as liver and spleen damage.Water dampness is unfavourable for transportation and transformation as dampness gathers phlegm,and liver‘wind’carries phlegm to the ear orifice,causing dizziness,or the ear orifice can be attacked due to the deficiency of yin and hyperactivity of yang in liver and kidney,resulting in sudden dizziness.Based on the pathogenesis theory of liver and spleen damage,the treatment principles should be based on strengthening the spleen and dispelling dampness,eliminating phlegm and extinguishing‘wind’.For‘yang-type'hyperactive liver,nourishing yin and suppressing yang,and the clearing of yang in the ears should always be the standard.展开更多
文摘Intracranial aneurysm, a localized dilation of arterial blood vessels in the Circle of Willis and its branches, is potentially life threatening, due to massive bleeding in the subarachnoid space upon rupture. In clinical practice, one minimally invasive surgical procedure is the implantation of a metallic stent to cover the aneurysm neck. This flow diverting device can reduce the flow into the aneurysm and enhance the prospect of thrombosis, a condition expected to reduce the risk of growth and rupture. The biomechanical and haemo-dynamic factors in stented and nonstented situations are studied by computational fluid dynamics. Unlike earlier models with straight or curved parent blood vessels, the aneurysm is now located near an arterial bifurcation. The influence of the aspect (depth to neck) ratio of the aneurysm on the flow dynamics will be emphasized, especially in the post-operation stages. More precisely, the maximum flow velocity, the variations of wall shear stress, the risk of stent migration and volumetric flow rate after endovascular treatment will be studied. Aneurysms with larger aspect ratios (i.e. smaller neck sizes for constant depth) generally pose a greater risk in terms of these flow parameters. These results will assist the applications and design of stents in future neurosurgical therapy. The approach is limited to a nonelastic model, without taking into account of questions like stent expansion and interaction with tissue.
文摘The diurnal and semidiurnal tidal wind field variations in the altitudes between 80 and 100 km of the earth's atmosphere over a mid-latitude station are studied by means of the phases of the zonal and meridional wind measurements made at Atlanta (34 ° N, 84 ° W). The rotation of diurnal tidal wind vector is seen to be clockwise at lower heights (80-86 km), swinging between clockwise and anti-clockwise at intermediate heights (88-96 km) and anti-clockwise at higher heights (96-100 km). The senses of rotation of diurnal and semidiurnal tidal wind vectors are compared between the stations located in the same and opposite hemispheres. The results are consistent with the tidal theory in the case of Atlanta and Adelaide (35°S, 139 ° E) whereas in the case of other stations considered in the present study, they showed marked variations.
文摘Small wastewater treatment plants (WWTP) are frequently located, by necessity, in remote and isolated sites, which increases the difficulty of its energy supply. Some of them are located near the seaside, in environmental sensible zones, and due to tourism activity of these sites, seasonal effects related with population size fluctuation can occur, which can originate certain inefficiencies concerning WWTP design and energy supply. The objective of this paper is to describe a step by step procedure for evaluation of the wind potential of sites that are dependent of in-situ energy generation, as well as, a case study on the utilization of the potential wind energy in Magoito WWTP (5000 p.e.). The employed methodology comprised the collection of one year of in-situ wind data and its validation by comparison with historical data of about 10 years of a nearby anemometric station. The data provided by the two anemometric stations was statistically treated. It allowed the analysis of the results from the two stations are promissory in terms of wind availability and velocity. Finally, it comprised the simulation of the local wind conditions for a considerable larger area in order to find the best site for locating a wind turbine.
文摘About 1.1 million people are estimated to have age-related macular degeneration in West Germany. Anatomical aspects of the normal macula and physiological ageing processes in the retina will be discribed including alterations in the choroid, in Bruch's membrane, the pigment epithelium and the sensory retina. Risk factors for the development of age-related macular degeneration are age per se, perhaps ethnologic characteristics, ocular characteristics, and perhaps environmental factors. The histopathology...
基金Shaanxi Province Famous TCM Doctor Zhang Xiong Studio[Shaan Wei TCM Development(2018)No.95]。
文摘The theory of"all winds and dizziness belong to the liver"provides a basis for 1ater plysicians to study the etiologic and pathogenesis of vertigo diseases.This theory of pathogenesis suggests that vertigo diseases are most closely related to the liver,so the mechanism can be simply understood as liver and spleen damage.Water dampness is unfavourable for transportation and transformation as dampness gathers phlegm,and liver‘wind’carries phlegm to the ear orifice,causing dizziness,or the ear orifice can be attacked due to the deficiency of yin and hyperactivity of yang in liver and kidney,resulting in sudden dizziness.Based on the pathogenesis theory of liver and spleen damage,the treatment principles should be based on strengthening the spleen and dispelling dampness,eliminating phlegm and extinguishing‘wind’.For‘yang-type'hyperactive liver,nourishing yin and suppressing yang,and the clearing of yang in the ears should always be the standard.
