5,580 research outputs found
Radiation-cooled Dew Water Condensers Studied by Computational Fluid Dynamic (CFD)
Harvesting condensed atmospheric vapour as dew water can be an alternative or
complementary potable water resource in specific arid or insular areas. Such
radiation-cooled condensing devices use already existing flat surfaces (roofs)
or innovative structures with more complex shapes to enhance the dew yield. The
Computational Fluid Dynamic - CFD - software PHOENICS has been programmed and
applied to such radiation cooled condensers. For this purpose, the sky
radiation is previously integrated and averaged for each structure. The
radiative balance is then included in the CFD simulation tool to compare the
efficiency of the different structures under various meteorological parameters,
for complex or simple shapes and at various scales. It has been used to precise
different structures before construction. (1) a 7.32 m^2 funnel shape was
studied; a 30 degree tilted angle (60 degree cone half-angle) was computed to
be the best compromise for funnel cooling. Compared to a 1 m^2 flat condenser,
the cooling efficiency was expected to be improved by 40%. Seventeen months
measurements in outdoor tests presented a 138 % increased dew yield as compared
to the 1 m^2 flat condenser. (2) The simulation results for 5 various condenser
shapes were also compared with experimental measurement on corresponding pilots
systems: 0.16 m^2 flat planar condenser, 1 m^2 and 30 degree tilted planar
condenser, 30 m^2 and 30 degree tilted planar condenser, 255 m^2 multi ridges,
a preliminary construction of a large scale dew plant being implemented in the
Kutch area (Gujarat, India)
Determination of Vacant Lattice Sites in Aluminium Alloys by X-ray Diffraction Technique
THE study of the structure of metals and alloys is
very important because this affords the possibility
of developing new alloys with improved properties
to be useful for meeting service requirements. Theories
based on ideal crystals fail miserably when applied to
real crystals of the metals and alloys, for example
the calculated Yield strength and breaking strength
of ideal crystals are 100 to 10,000 times more than the
observed strength of real crystals. The reason is that
the crystals contain many haws and irregularities, so
it is felt that a detailed knowledge of vacant lattice
sites in alloys will be useful, because of their effects
on physical and mechanical properties. The object of
this investigation is to find out the effect of copper
on the lattice parameter and vacant lattice sites in
aluminium
Presurgical thalamic hubness predicts surgical outcome in temporal lobe epilepsy.
OBJECTIVE: To characterize the presurgical brain functional architecture presented in patients with temporal lobe epilepsy (TLE) using graph theoretical measures of resting-state fMRI data and to test its association with surgical outcome.
METHODS: Fifty-six unilateral patients with TLE, who subsequently underwent anterior temporal lobectomy and were classified as obtaining a seizure-free (Engel class I, n = 35) vs not seizure-free (Engel classes II-IV, n = 21) outcome at 1 year after surgery, and 28 matched healthy controls were enrolled. On the basis of their presurgical resting-state functional connectivity, network properties, including nodal hubness (importance of a node to the network; degree, betweenness, and eigenvector centralities) and integration (global efficiency), were estimated and compared across our experimental groups. Cross-validations with support vector machine (SVM) were used to examine whether selective nodal hubness exceeded standard clinical characteristics in outcome prediction.
RESULTS: Compared to the seizure-free patients and healthy controls, the not seizure-free patients displayed a specific increase in nodal hubness (degree and eigenvector centralities) involving both the ipsilateral and contralateral thalami, contributed by an increase in the number of connections to regions distributed mostly in the contralateral hemisphere. Simulating removal of thalamus reduced network integration more dramatically in not seizure-free patients. Lastly, SVM models built on these thalamic hubness measures produced 76% prediction accuracy, while models built with standard clinical variables yielded only 58% accuracy (both were cross-validated).
CONCLUSIONS: A thalamic network associated with seizure recurrence may already be established presurgically. Thalamic hubness can serve as a potential biomarker of surgical outcome, outperforming the clinical characteristics commonly used in epilepsy surgery centers
A Study of Dew Water Yields on Galvanized Iron Roof in Kothara (North-West India)
In order to determine what amount of dew water can be collected without much investment during the dry season (October –May) in north - west India, a study was performed on plain, un-insulated, corrugated galvanized iron roofs that are common in this rural region. Between October 1, 2004 and May 31, 2005, the cumulative dew yield on a 18 m2 double - sloped (30�) test roof was 113.5 L. The west side gave 35 % higher water yield than the east side. The use of thermal insulation and more IR radiative materials would have increased this yield by 40 % (160 L). An analysis of dew events is made with meteorological data. It shows that the variable relative humidity is the most important parameter, which in turn is strongly correlated with the average wind direction with respect to monsoon direction. The cumulative dew water yield (6.3 mm) remains modest when compared with the average rain fall (300 mm). But dew occurs far more frequently than rain and it forms precisely during the dry season when water is most scarce.
Risk of hypertension with bevacizumab, an antibody against vascular endothelial growth factor A: a systematic review and meta-analysis
Bevacizumab, a humanized antibody against VEGF, is effective in the treatment of patients with many cancers. However, as with many therapeutic agents, significant side effects are associated with bevacizumab, Hypertension is one of the predominant toxicity. We performed a systematic review and meta-analysis of published clinical trials of bevacizumab to quantify the risk of hypertension. 15 studies following PRISMA guidelines and matching inclusion and exclusion criteria were collected in which a group of patients were either treated with Bevacizumab and a concurrent chemotherapy and another group treated with Placebo and the same chemotherapy. Relative risk (RR) was calculated. P<0.05 was considered statistically significant. RevMan 5.3 software was used for the analysis. A total of 13,070 patients were included. Bevacizumab was associated with a significant increased risk of overall hypertension (RR=3.509; 95% C.I:2.451 to 5.023). 11 trials are included for determining the risk of Grade 3 hypertension including 8799 patients with a significant increased risk (RR=3.909; 95%C.I:1.983 to 7.707). 7 trials are included for determining the risk of hypertension at low dose (2.5 mg/kg/cycle) including 3691 patients associated with a significant increased (RR=2.640; 95%C.I: 1.408 to 4.950). 10 trials are included for determining the risk of hypertension at high dose (5 mg/kg/cycle) including 9379 patients associated with a significant (RR=4.036; 95%C.I: 2.948 to 5.525). Our meta-analysis has demonstrated that bevacizumab may be associated with a significantly increased risk of hypertension in patient with a variety of metastatic solid tumors irrespective of dosing
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An NGO-Implemented Community-Clinic Health Worker Approach to Providing Long-Term Care for Hypertension in a Remote Region of Southern India.
Poor blood pressure control results in tremendous morbidity and mortality in India where the leading cause of death among adults is from coronary heart disease. Despite having little formal education, community health workers (CHWs) are integral to successful public health interventions in India and other low- and middle-income countries that have a shortage of trained health professionals. Training CHWs to screen for and manage chronic hypertension, with support from trained clinicians, offers an excellent opportunity for effecting systemwide change in hypertension-related burden of disease. In this article, we describe the development of a program that trained CHWs between 2014 and 2015 in the tribal region of the Sittilingi Valley in southern India, to identify hypertensive patients in the community, refer them for diagnosis and initial management in a physician-staffed clinic, and provide them with sustained lifestyle interventions and medications over multiple visits. We found that after 2 years, the CHWs had screened 7,176 people over age 18 for hypertension, 1,184 (16.5%) of whom were screened as hypertensive. Of the 1,184 patients screened as hypertensive, 898 (75.8%) had achieved blood pressure control, defined as a systolic blood pressure less than 140 and a diastolic blood pressure less than 90 sustained over 3 consecutive visits. While all of the 24 trained CHWs reported confidence in checking blood pressure with a manual blood pressure cuff, 4 of the 24 CHWs reported occasional difficulty documenting blood pressure values because they were unable to write numbers properly. They compensated by asking other CHWs or members of their community to help with documentation. Our experience and findings suggest that a CHW blood pressure screening system linked to a central clinic can be a promising avenue for improving hypertension control rates in low- and middle-income countries
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