126 research outputs found

    Fast design optimization of UWB antenna with WLAN Band-Notch

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    In this paper, a methodology for rapid design optimization of an ultra-wideband ( UWB) monopole antenna with a lower WLAN band-notch is presented. The band-notch is realized using an open loop resonator implemented in the radiation patch of the antenna. Design optimization is a two stage process, with the first stage focused on the design of the antenna itself, and the second stage aiming at identification of the appropriate dimensions of the resonator with the purpose of allocating the band-notch in the desired frequency range. Both optimization stages are realized using surrogate-based optimization involving variable-fidelity electromagnetic ( EM) simulation models as well as an additive response correction ( first stage), and sequential approximate optimization ( second stage). The final antenna design is obtained at the CPU cost corresponding to only 23 high-fidelity EM antenna simulations

    Comparative study of soils of different landforms under rubber with special reference to erodibility indices/factor

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    Soil erodibility factor ‘K’ is a quantitative description of the inherent erodibility of a particular soil and it represents the susceptibility of soil particles to detachment and transport by both rainfall and runoff. Soils of different landforms under rubber (Hevea brasiliensis) in Kerala were studied with special reference to erodibility factor. Soils of nineteen-soil series developed on different landforms representing 70 per cent of the total potential rubber growing area were selected and the susceptibility of these soils to erosion was assessed by soil ratios and erodibility factor ‘K’ using soil survey information. The soil erodibility factor ‘K’ varies from 0.273 to 0.473, 0.353 to 481, 0.299 to 0.459 and 0.287 to 0.468 for soils developed on charnockite, laterite, khondalite and granite-gneiss landform, respectively. The soils of Vazhoor and Vijayapuram series developed on charnockite, Kaipuzha and Anayadi series of laterite, Kadambanad series of khondalite and soils of Pallippadi series identified in the granite-gneiss landform contained relatively high values of clay ratio and silt/clay ratio indicating that these soils are more susceptible to erosion than the other soils. Among the landforms, soils developed on laterite were relatively more susceptible to erosion compared to soils of other landforms. The study also revealed that soils with higher content of intermediate particle size fractions between sand and clay showed more erodibility risk than the soils with higher clay and higher sand content. In general, all the soils have moderate to high risk of erosion, thus needs suitable soil conservation measures to reduce soil loss and protect existing productivity

    Cost-efficient modeling of antenna structures using Gradient Enhanced Kriging

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    Reliable yet fast surrogate models are indispensable in the design of contemporary antenna structures. Data-driven models, e.g., based on Gaussian Processes or support-vector regression, offer sufficient flexibility and speed, however, their setup cost is large and grows very quickly with the dimensionality of the design space. In this paper, we propose cost-efficient modeling of antenna structures using Gradient-Enhanced Kriging. In our approach, the training data set contains, apart from the EM-simulation responses of the structure at hand, also derivative data at the respective training locations obtained at little extra cost using adjoint sensitivity techniques. We demonstrate that introduction of the derivative information into the model allows for considerable reduction of the model setup cost (in terms of the number of training points required) without compromising its predictive power. The Gradient-Enhanced Kriging technique is illustrated using a dielectric resonator antenna structure. Comparison with conventional Kriging interpolation is also provided

    Impact of removal of rubber plantations for urbanization on CO2 mitigating capacity by the loss of carbon sink in Kerala state, India

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    Mitigating climate change and global warming through carbon sequestration by tree ecosystems is of prime importance since they are cost-effective, environmentally friendly and ecologically sustainable. Urbanization is a part of development, and rubber plantations are usually removed for this purpose, especially in Kerala, the southern state of India. Besides latex, the economic produce, and the associated income, the rubber tree is a fairly good sink for carbon in its biomass, with an average carbon content of 42 per cent and substantial carbon stock in the soil. In the present study, an account of total carbon loss by the removal of rubber plantation for urbanization and developmental activities are given. The present popular clone (RRII 105) existing in major share (85%) of the total rubber cultivation in India accounts for carbon sink loss 57 t ha-1, 57.5 t ha-1, 43.2 t ha-1 for 23 years and 148 t ha-1, 75 t ha-1 and 62.1 t ha-1 for 30 years from biomass, litterfall and sheet rubber respectively. The recent clones RRII 414, RRII 429 and RRII 417 have higher growth rates and higher biomass (44-50 per cent) carbon sink loss compared to the existing popular clone RRII 105. The carbon sink loss in the form of stored carbon in soil is 56.5, with a soil carbon content between 1.2 to 2 per cent. Due to the growth variation in diverse environments with extreme climatic conditions, the clones recorded differences in carbon stock and carbon sink loss. The central region of Kerala showed a higher loss, and a lower loss was in the drought-affected northern region than the southern region. The total carbon sink losses for 23 and 30 years were 214.2 and 341.5 t ha-1, respectively. This study points out that the serious carbon sink loss due to the removal of rubber plantations results in disturbing the self-sustained, carbon-friendly and economically sound perennial rubber ecosystem. Vegetation having higher C-sequestration potential and trees with higher lignin content is essential to increase carbon capture for mitigating the impact of the removal of plantations. From the present study, it is clear that the removal of rubber plantations is affecting the carbon sink loss, thereby the CO2 mitigating capacity, and is a serious matter of concern

    Posterior Uterine Rupture Causing Fetal Expulsion into the Abdominal Cavity: A Rare Case of Neonatal Survival

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    Introduction. Uterine rupture is a potentially catastrophic complication of vaginal birth after caesarean section. We describe the sixth case of posterior uterine rupture, with intact lower segment scar, and the first neonatal survival after expulsion into the abdominal cavity with posterior rupture. Case Presentation. A multiparous woman underwent prostaglandin induction of labour for postmaturity, after one previous caesarean section. Emergency caesarean section for bradycardia revealed a complete posterior uterine rupture, with fetal and placental expulsion. Upon delivery, the baby required inflation breaths only. The patient required a subtotal hysterectomy but returned home on day 5 postnatally with her healthy baby. Discussion. Vaginal birth after caesarean section constitutes a trial of labour, and the obstetrician must be reactive to labour events. Posterior uterine rupture is extremely rare and may occur without conventional signs. Good maternal and fetal outcome is possible with a prompt, coordinated team response

    An analysis of stromal expression of CD10 in invasive ductal carcinoma of breast and its correlation with histological grade

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    Background: Breast cancer is one of the most common cancers among women in India. Stroma has an important role in the pathogenesis of carcinoma of breast. Stromal marker can be novel marker for assessing the prognosis of breast cancer.Methods: With the representative sections of 30 invasive ductal carcinoma of breast NOS type Hematoxylin and eosin staining was done. Immunohistochemistry was done with CD10. CD10 expression in stroma in cases and control slides were studied and statistically analyzed with histopathological grade.Results: 46% (14 out of 30) of cases showed strong positivity for stromal CD10. Only two cases of strong positivity for CD10 were noted in the adjacent normal breast parenchyma. Stromal expression of CD10 had a statistically significant association with breast carcinoma than in control slides, p value is 0.002. 77% (10 out of 13) of CD10 positive cases were high grade carcinomas. Association of CD10 expression with high grade tumour was statistically significant (p value is 0.04 which is less than 0.05). No association was found with mean age.Conclusions: As the grade of breast carcinoma increases the stromal expression of CD10 is increased. Stromal CD10 expression is directly correlated with higher tumour grade. CD10 could be used as novel prognostic marker and used to develop newer drugs.

    Ssr-based molecular profiling of selected donors of wide compatibility, elongated uppermost internode, stigma exsertion and submergence tolerance traits and parental lines of commercial rice (o. Sativa l.) Hybrids

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    Molecular breeding plays an important role in sustainable agriculture development. Hybrid rice technology aims to increase the yield potential of rice beyond the level of inbred high-yielding varieties (HYVs) by exploiting the phenomenon of hybrid vigour or heterosis. Improvement of hybrid rice parental line is necessary to meet the food security problem. Parental polymorphism was carried with 215 SSR markers between five recurrents and ten donors. During the foreground selection, both reported markers (S5-Indel and BF-S5) were validated for wide compatibility, 2 out of 14 (ART5 and SC3) validates for submergence tolerance, one out of two (RM5) validate for stigma exsertion, whereas 2 of 3 markers (RM5970, RM3476) validated for elongated uppermost internode traits between recurrents and donors. For background selection, maximum polymorphic markers (112) between IR58025eB i.e improved maintainer line with elongated uppermost internode and Oryza meridionalis and minimum polymorphic markers (42) between IR79156B and IR91-1591-3 were found. Marker-assisted backcrossing accelerate, the transfer of gene of interest in desirable genetic background. Genotypes IR58025B and IR58025eB emerged as genetically most similar with a value of 97%. The genotypes IR64 Sub1 and Oryza meridionalis were found most divergent showing 33% genetic similarity. Dissimilarity coefficient of the generated information obtained on genetic relatedness would be supportive in further rice breeding program

    Genetic variability in trait-specific rice germplasm groups based on coefficient of parentage, SSR markers and fertility restoration

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    To maximize heterosis, it is important to understand the genetic diversity of germplasm and associate useful phenotypic traits such as fertility restoration for hybrid rice breeding. The objectives of the present study were to characterize genetic diversity within a set of rice germplasm groups using coefficient of parentage (COP) values and 58 simple sequence repeat (SSR) markers for 124 genotypes having different attributes such as resistance/tolerance to various biotic and abiotic stresses. These lines were also used for identifying prospective restorers and maintainers for wild abortive-cytoplasmic male sterile (CMS) line. The mean COP value for all the lines was 0.11, indicating that the genotypes do not share common ancestry. The SSR analysis generated a total of 268 alleles with an average of 4.62 alleles per locus. The mean polymorphism information content value was 0.53, indicating that the markers selected were highly polymorphic. Grouping based on COP analysis revealed three major clusters pertaining to the indica, tropical japonica and japonica lines. A similar grouping pattern with some variation was also observed for the SSR markers. Fertility restoration phenotype based on the test cross of the 124 genotypes with a CMS line helped identify 23 maintainers, 58 restorers and 43 genotypes as either partial maintainers or partial restorers. This study demonstrates that COP analysis along with molecular marker analysis might encourage better organization of germplasm diversity and its use in hybrid rice breeding. Potential restorers identified in the study can be used for breeding high-yielding stress-tolerant medium-duration rice hybrids, while maintainers would prove useful for developing new rice CMS lines
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