174 research outputs found
Phase ambiguity of the threshold amplitude in pp -> pp\pi^0
Measurements of spin observables in pp -> {\vec p}{\vec p}\pi^0 are suggested
to remove the phase ambiguity of the threshold amplitude. The suggested
measurements complement the IUCF data on {\vec p}{\vec p} -> pp\pi^0 to
completely determine all the twelve partial wave amplitudes, taken into
consideration by Mayer et.al. [15] and Deepak, Haidenbauer and Hanhart [20].Comment: 4 pages, 1 table
Dynamic Split Tensile Strength of Basalt, Granite, Marble and Sandstone: Strain Rate Dependency and Fragmentation
The aim of this study is to understand the strength behaviour and fragment size of rocks during indirect, quasi-static and dynamic tensile tests. Four rocks with different lithological characteristics, namely: basalt, granite, sandstone, and marble were selected for this study. Brazilian disc experiments were performed over a range of strain rates from ~ 10<jats:sup/>–5 /s to 2.7 × 10<jats:sup/>1 /s using a hydraulic loading frame and a split Hopkinson bar. Over the range of strain rates, our measurements of dynamic strength increase are in good agreement with the universal theoretical scaling relationship of (Kimberley et al., Acta Mater 61:3509–3521, 2013). Dynamic fragmentation during split tension mode failure has received little attention, and in the present study, we determine the fragment size distribution based on the experimentally fragmented specimens. The fragments fall into two distinct groups based on the nature of failure: coarser primary fragments, and finer secondary fragments. The degree of fragmentation is assessed in terms of characteristic strain rate and is compared with existing theoretical tensile fragmentation models. The average size of the secondary fragments has a strong strain rate dependency over the entire testing range, while the primary fragment size is less sensitive at lower strain rates. Marble and sandstone are found to generate more pulverised secondary debris when compared to basalt and granite. Furthermore, the mean fragment sizes of primary and secondary fragments are well described by a power-law function of strain rate
Dynamic Compressive Strength and Fragmentation in Felsic Crystalline Rocks
Brittle deformation in rocks depends upon loading rate; with increasing rates, typically greater than ~102 s‐1, rocks become significantly stronger and undergo increasingly severe fragmentation. Dynamic conditions required for rate‐dependent brittle failure may be reached during impact events, seismogenic rupture, and landslides. Material characteristics and fragment characterization of specific geomaterials from dynamic loading are only approximately known. Here we determine the characteristic strain rate for dynamic behavior in felsic crystalline rocks, including anisotropy, and describe the resulting fragments. Regardless of the type of felsic crystalline rock or anisotropy, the characteristic strain rate is the same within uncertainties for all tested materials, with an average value of 229 ± 81 s‐1. Despite the lack of variation of the critical strain rate with lithology, we find that the degree of fragmentation as a function of strain rate varies depending on material. Scaled or not, the fragmentation results are inconsistent with current theoretical models of fragmentation. Additionally, we demonstrate that conditions during impact cratering, where the impactor diameter is less than ~100 m, are analogous to the experiments carried out here, and therefore that dynamic strengthening and compressive fragmentation should be considered as important processes during impact cratering
Patterns of accumulation of camptothecin, an anti-cancer alkaloid in Nothapodytes nimmoniana Graham., in the Western Ghats, India: Implications for identifying high-yielding sources of the alkaloid
Camptothecin, a monoterpene indole alkaloid, is regarded
as one of the most promising anticancer drugs of the
twenty-first century. Among the various plant sources,
the highest yields of the alkaloid are reported from
Nothapodytes nimmoniana (Icacinaceae), a small tree
distributed in the Indian subcontinent. Because of the
enormous demand for the chemical worldwide, there has been an indiscriminate extraction of the trees from many parts of India, especially from the Western Ghats, a mega-diversity forest range along the western coast of
India. Recently the tree has been assigned a vulnerable
status. In an effort to conserve the remaining populations of the species and to identify high-yielding sources of the alkaloid, attempts are being initiated in chemically profiling the species. As a first step in this direction, we have attempted to establish the general patterns of accumulation of camptothecin in N. nimmoniana across individuals, plant parts, plant size and sex of plants, in the Western Ghats. Individual trees with as high as 100 per cent greater camptothecin content than hitherto reported have been found. The study indicates the potentiality of further screening populations of N. nimmoniana to identify high-yielding sources that can be used for developing in vitro production systems or for establishing high-yielding clonal populations
CPW Fed T-Shaped Wearable Antenna for ISM Band, Wi-Fi, WiMAX, WLAN and Fixed Satellite Service Applications
The placement of wearable products integrated with telecommunication systems is having a good impact on healthcare communication all over the world. Embedded communication devices like antennas and RF devices are helping doctors to assess the condition of patients from remote locations. The present work deals with the design and development of a coplanar waveguide fed wearable antenna for ISM band (2.4–2.5 GHz), Wi-Fi, WLAN (2.4–2.48 GHz), WiMAX (3.4–3.6 GHz), and fixed satellite service (3.6–3.7 GHz and 9–11.5 GHz) applications. The designed antenna on jeans substrate (50 × 40 × 1.6 mm) provides a 1.7 GHz bandwidth with a gain of 4.6 dB. A parametric study of different fabrics and the performance characteristics of bending angles are also provided in this work from the application point of view. The simulated results obtained from CST tool and measured results of fabric material based antenna on vector network analyzer are correlated with each other
Persistence of Diphtheria, Hyderabad, India, 2003–2006
During 2003–2006, diphtheria rates in Hyderabad, India, were higher among persons 5–19 years of age, women, and Muslims than among other groups. Vaccine was efficacious among those who received >4 doses. The proportion of the population receiving boosters was low, especially among Muslims. We recommend increasing booster dose coverage
Retinal vascular tortuosity in schizophrenia and bipolar disorder
\u3cp\u3eThe micro-vasculature of retina and brain share common morphological, physiological, and pathological properties. Retina being easily accessible, retinal vascular examination provides an indirect assessment of cerebral vasculature. Considering the high prevalence of vascular morbidity in SCZ and BD a few studies have examined retinal vascular caliber and have reported increased retinal venular caliber in schizophrenia (SCZ). Retinal vascular tortuosity could serve as a better structural measure than caliber as it is static and less susceptible to pulse period variations. However, to date, no study has examined retinal vascular tortuosity in SCZ and bipolar disorder (BD). Hence, we examined retinal vascular tortuosity in comparison with healthy volunteers (HV). We included 255 subjects (78 HV, 79 SCZ, and 86 BD) in the age range of 18 to 50 years. Trained personnel acquired images using a non-mydriatic fundus camera. To measure the average retinal arteriolar tortuosity index (RATI) and retinal venular tortuosity index (RVTI), we used a previously validated, semi-automatic algorithm. The results showed significant differences across the three groups in RATI but not in RVTI; both BD and SCZ had significantly increased RATI compared to HV. There was also a significant difference between SCZ and BD, with BD having higher RATI. If shown to be of predictive utility in future longitudinal studies, it has the potential to identify patients at risk of development of adverse vascular events. As retinal vascular imaging is non-invasive and inexpensive, it could serve as a proxy marker and window to cerebral vasculature.\u3c/p\u3
The Role of Imported Cases and Favorable Meteorological Conditions in the Onset of Dengue Epidemics
Dengue/dengue hemorrhagic fever is the world's most widely spread mosquito-borne arboviral disease and threatens more than two-thirds of the world's population. Cases are mainly distributed in tropical and subtropical areas in accordance with vector habitats for Aedes aegypti and Ae. albopictus. However, the role of imported cases and favorable meteorological conditions has not yet been quantitatively assessed. This study verified the correlation between the occurrence of indigenous dengue and imported cases in the context of weather variables (temperature, rainfall, relative humidity, etc.) for different time lags in southern Taiwan. Our findings imply that imported cases have a role in igniting indigenous outbreaks, in non-endemics areas, when favorable weather conditions are present. This relationship becomes insignificant in the late phase of local dengue epidemics. Therefore, early detection and case management of imported cases through timely surveillance and rapid laboratory-diagnosis may avert large scale epidemics of dengue/dengue hemorrhagic fever. An early-warning surveillance system integrating meteorological data will be an invaluable tool for successful prevention and control of dengue, particularly in non-endemic countries
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