Triton Electric Form Factor at Low-Energies

Making use of the Effective Field Theory(EFT) expansion recently developed by the authors, we compute the charge form factor of triton up to next-to-next-to-leading order (N$^2$LO). The three-nucleon forces(3NF) is required for renormalization of the three-nucleon system and it effects are predicted for process and is qualitatively supported by available experimental data. We also show that, by including higher order corrections, the calculated charge form factor and charge radius of $^3$H are in satisfactory agreement with the experimental data and the realistic Argonne $v_{18}$ two-nucleon and Urbana IX potential models calculations. This method makes possible a high precision few-body calculations in nuclear physics. Our result converges order by order in low energy expansion and also cut-off independent.Comment: 9 pages, 5 figures and 1 tabl

Two-dimensional Phononic Crystals with Acoustic-Band Negative Refraction

A two-dimensional phononic crystal (PC) can exhibit longitudinal-mode negative energy refraction on its lowest (acoustical) frequency pass band. The effective elastodynamic properties of a typical PC are calculated and it is observed that the components of the effective density tensor can achieve negative values at certain low frequencies on the acoustical branches for the longitudinal-mode pass-band, and that negative refraction may be accompanied by either positive or negative effective density. Furthermore, such a PC has a high anisotropy ratio at certain low frequencies, offering potential for application to acoustic cloaking where effective material anisotropy is essential.Comment: in Proceedings of the ASME 2016 Conference on Smart Materials, Adaptive Structures and Intelligent Systems, Stowe, VT (2016

A Study on Clustering for Clustering Based Image De-Noising

In this paper, the problem of de-noising of an image contaminated with Additive White Gaussian Noise (AWGN) is studied. This subject is an open problem in signal processing for more than 50 years. Local methods suggested in recent years, have obtained better results than global methods. However by more intelligent training in such a way that first, important data is more effective for training, second, clustering in such way that training blocks lie in low-rank subspaces, we can design a dictionary applicable for image de-noising and obtain results near the state of the art local methods. In the present paper, we suggest a method based on global clustering of image constructing blocks. As the type of clustering plays an important role in clustering-based de-noising methods, we address two questions about the clustering. The first, which parts of the data should be considered for clustering? and the second, what data clustering method is suitable for de-noising.? Then clustering is exploited to learn an over complete dictionary. By obtaining sparse decomposition of the noisy image blocks in terms of the dictionary atoms, the de-noised version is achieved. In addition to our framework, 7 popular dictionary learning methods are simulated and compared. The results are compared based on two major factors: (1) de-noising performance and (2) execution time. Experimental results show that our dictionary learning framework outperforms its competitors in terms of both factors.Comment: 9 pages, 8 figures, Journal of Information Systems and Telecommunications (JIST

Quasi-static and Dynamic Behavior of Additively Manufactured Metallic Lattice Cylinders

Lattice structures have tailorable mechanical properties which allows them to exhibit superior mechanical properties (per unit weight) beyond what is achievable through natural materials. In this paper, quasi-static and dynamic behavior of additively manufactured stainless steel lattice cylinders is studied. Cylindrical samples with internal lattice structure are fabricated by a laser powder bed fusion system. Equivalent hollow cylindrical samples with the same length, outer diameter, and mass (larger wall thickness) are also fabricated. Split Hopkinson bar is used to study the behavior of the specimens under high strain rate loading. It is observed that lattice cylinders reduce the transmitted wave amplitude up to about 21% compared to their equivalent hollow cylinders. However, the lower transmitted wave energy in lattice cylinders comes at the expense of a greater reduction in their stiffness, when compared to their equivalent hollow cylinder. In addition, it is observed that increasing the loading rate by five orders of magnitude leads to up to about 36% increase in the peak force that the lattice cylinder can carry, which is attributed to strain rate hardening effect in the bulk stainless steel material. Finite element simulations of the specimens under dynamic loads are performed to study the effect of strain rate hardening, thermal softening, and the failure mode on dynamic behavior of the specimens. Numerical results are compared with experimental data and good qualitative agreement is observed.Comment: 20th Biennial Conference of the APS Topical Group on Shock Compression of Condensed Matte

An Optimized Combination of a Large Grid Connected PV System along with Battery Cells and a Diesel Generator

Environmental, economical and technical benefits of photovoltaic (PV) systems make them to be used in many countries. The main characteristic of PV systems is the fluctuations of their output power. Hence, high penetration of PV systems into electric network could be detrimental to overall system performance. Furthermore, the fluctuations in the output power of PV systems make it difficult to predict their output, and to consider them in generation planning of the units. The main objective of this paper is to propose a hybrid method which can be used to control and reduce the power fluctuations generated from large grid- connected PV systems. The proposed method focuses on using a suitable storage battery along with curtailment of the generated power by operating the PV system below the maximum power point (MPP) and deployment of a diesel generator. These methods are analyzed to investigate the impacts of implementing them on the economical benefits that the PV system owner could gain. To maximize the revenues, an optimization problem is solved

Passivhaus summer overheating: the development of an effective natural ventilation system

Concern regarding overheating potential has been growing in the UK as buildings are being built to higher standards like Passivhaus. Lack of window operation due to noise and security implications specifically at night, alongside higher expected temperatures in the future can only add to this concern. Furthermore the quality of incoming fresh air through windows in Passivhaus dwellings could be lower compared to filtered air in MVHR systems. The aim of this research is to investigate the possibility of overheating in reference Passivhaus dwellings and consequently, to examine and propose a remedial natural ventilation strategy and system for the non-winter period. The internal temperatures, indoor CO2 levels alongside frequency and duration of window openings were recorded using data loggers and sensors. A dynamic thermal model was created in DesignBuilder using data from the original PHPP model and further amended by results from monitoring, creating a base case model. A specific natural ventilation system was modelled using the base case model to increase efficiency and effectiveness of natural ventilation. The proposed system was also tested for the winter period in terms of airtightness and thermal bridging as well as forecasted future climate data. The proposed system increases natural ventilation rates compared to the original design, thereby reducing summer overheating for current and future climate by around 20%. Passivhaus designers can benefit from this system for new building designs or for refurbishment of existing Passivhaus building stock that could encounter overheating in the future. The system can be tested in the PHPP calculation allowing the elimination of all window operations during the cooling season

Modified Gaussian Radial Basis Function Method for the Burgers Systems

In this paper, the systems of variable-coefficient coupled Burgers equation are solved by a free mesh method. The method is based on the collocation points with the modified Gaussian (MGA) radial basis function (RBF). Dependent parameters and independent parameters and their effect on the stability are shown. The accuracy and efficiency of the method has been checked by two examples. The results of numerical experiments are compared with analytical solutions by calculating errors infinity-norm

Changes in biochemical characteristics and Na and K content of caper (Capparis spinosa L.) seedlings under water and salt stress

In order to investigate the effect of water and salt stress on caper (Capparis spinosa L.) seedlings, a randomized complete block design with five replications was carried out in 2013 at Shiraz University, Iran. Water stress had three levels: 100 % (control), 75 %, and 5 % field capacity (FC), and five levels of salinity were applied: 0 (control), 4, 8, 12, and 18 dSm^(−1). The results indicated that salinity had a significantly negative effect on chlorophyll content of caper seedlings, while drought increased this content. The carotenoid content in caper seedlings under water and salinity stress was significantly increased. Proline and total protein content increased also under both salinity and water stress. Antioxidant enzyme activity; superoxide dismutase (SOD), catalase (CAT), peroxidase (POD) and ascorbate peroxidase (APX) also increased in response of salinity and drought. Salinity stress significantly increased the content of Na^+ in cells but decreased K^+ content. It seems that caper seedlings could tolerate a salinity level up to 4–8 dSm^(−1) as well as water stress of 75 % FC, no significant differences were observed between these two salinity levels, the water stress level and the control. The interaction effect of water stress and salinity had a significant effect on biochemical characteristics of caper. The highest content of carotenoid, proline and total protein content were obtained in 50 % FC and 18 dSm^(−1).The results of biochemical characteristics and leaf content of K+ and Na+ suggest that caper plant is a very tolerant species to salinity and drought stress which make it a suitable crop for most arid and semi-arid regions of Iran

Antioxidant activity of Trifolium resupinatum L. exposed to different extracts from leaves, flowers and shoots of Prangos ferulacea

Prangos ferulacea is a member of Apiaceae family, is a popular fodder for livestock production and an important species in rangeland restoration. The objectives of the research are the comparative phytotoxic activity of aqueous and hydroalcoholic extracts obtained from different organs (flower, shoot and leaf) of P. ferulacea on antioxidant response of Trifolium resupinatum was investigated in a laboratory bioassay. Antioxidant enzyme activities including catalase (CAT), peroxidase (POD), ascorbic peroxidase (APX), and superoxide dismutase (SOD), in line with content of malondialdehyde (MDA) and hydrogen peroxide were measured. Results indicated that hydroalcoholic extract of P. ferulaceae flower possess the highest total phenolic content as well as highest phytotoxic effect on T. resupinatum. The highest antioxidant enzyme activity belonged to hydroalcoholic treatment. The treated T. resupinatum seedlings experienced lipid peroxidation at high extract concentrations (12% of hydroalcoholic and 100% of aqueous extract) as evidenced by increased concentration of MDA. In response to this, the activities of SOD, CAT, POD and APX increased at lower extract concentrations but significantly dropped as concentrations increased. According to results of this study, rehabilitation of T. resupinatum sites through the use of P. ferulaceae will probably not be successful