General F-theory models with tuned (SU⁡(3)×SU⁡(2)×U⁡(1))/Z6(\operatorname{SU}(3) \times \operatorname{SU}(2) \times \operatorname{U}(1)) / \mathbb{Z}_6 symmetry

We construct a general form for an F-theory Weierstrass model over a general base giving a 6D or 4D supergravity theory with gauge group $(\operatorname{SU}(3) \times \operatorname{SU}(2) \times \operatorname{U}(1)) / \mathbb{Z}_6$ and generic associated matter, which includes the matter content of the standard model. The Weierstrass model is identified by unHiggsing a model with $\operatorname{U}(1)$ gauge symmetry and charges $q \le 4$ previously found by the first author. This model includes two distinct branches that were identified in earlier work, and includes as a special case the class of models recently studied by Cveti\v{c}, Halverson, Lin, Liu, and Tian, for which we demonstrate explicitly the possibility of unification through an $\operatorname{SU}(5)$ unHiggsing. We develop a systematic methodology for checking that a parameterized class of F-theory Weierstrass models with a given gauge group $G$ and fixed matter content is generic (contains all allowed moduli) and confirm that this holds for the models constructed here.Comment: 36 pages, LaTe

Behaviour of Unreinforced Masonry

Unreinforced Masonry (URM) structures can simply defined as structure without any reinforcement. URM is a common material for building construction but is known for its seismic vulnerability due to its heavy weight, high stiffness and negligible strength. URM structures are commonly used in developing countries like India for low rise building up to two story in rural area. Damage to those structures results in loss of life and cultural heritage. The main objective of the present thesis is to know the lateral behaviour of URM structure, and understand the concept of equivalent frame modelling (EFM). In the present work inverted triangular and uniform distribution lateral loads are used to study the nonlinear behaviour of masonry. There are several methods to carry out Static Pushover (SPO) analysis of URM, but Equivalent Frame Modelling is the simple one. EFM is being used for modeling the non-linear behavior of masonry by providing flexural and shear hinges in the model. EFM is nothing but assuming wall with opening as combination of horizontal and vertical members. The plastic hinges were used in SPO analyses since they allow the user to accurately follow the structural performance beyond the elastic limit at each step of the incremental analysis. Perfectly rigid plastic hinges were assumed as recommended in literature reviews and modelling is done in SAP2000 software. In order to know which property of masonry is sensitive to lateral behaviour, sensitivity analysis is carried out. Sensitivity analysis was carried out by varying all parameters with 5%, mean and 95% value. Tornado diagram is used to represent the results of sensitivity. It was found that except compressive strength all other parameters are affecting the lateral behaviour. The fragility can be regarded as one of the most important tool for performance based design of structures. The fragility curves are developed by using HAZUS methodology. Different damage levels such as slight, moderate, extensive and complete damage state are considered to represent variability in seismic performance of building and finally fragility curves were obtained for three damage state quality levels of masonry based on spectral displacements and damage probability. It is observed that the building have more probability for moderate damage. Different brick masonries are considered, to compare the results of the pushover

Computational Fluid Dynamics Analysis of Freeze Drying Process and Equipment

Freeze drying is an important, but expensive, inefficient and time consuming process in the pharmaceutical, chemical and food processing industries. Computational techniques could be a very effective tool in predictive design and analysis of both freeze drying process and equipment. This work is an attempt at using Computational Fluid Dynamics(CFD) and numerical simulations as a tool for freeze drying process and equipment design. Pressure control is critical in freeze dryers, keeping in view the product stability. In industrial freeze dryers, loss of pressure control can lead to loss of an entire batch. Pressure variation within the chamber could also lead to batch inhomogeneity, especially in industrial scale dryers. The low-pressure environment and the relatively small flow velocities make it difficult to quantify the flow structure experimentally. The current work presents a three-dimensional multi-species computational fluid dynamics model for vapor flow in a laboratory scale freeze-dryer validated with experimental data and analytical expressions. The model accounts for the presence of a non-condensable gas such as nitrogen or air using a continuum multi-species model. The flow structure at different sublimation rates, chamber pressures and shelf-gaps are systematically investigated. Emphasis has been placed on accurately predicting the pressure variation across the subliming front. It was found that while the pressure variation increased linearly with sublimation rate in the range of 0.5 kg/hr/m2 to 1.3 kg/hr/m2, the variation was more sensitive at shelf gaps approaching about at 2.1 cm and negligible at gaps close to 9 cm. While the results are found to agree within 10\% of measurements made for the range of shelf gaps and sublimation rates investigated here, the analytical solution is found to be more accurate for smaller shelf gaps. The current work presents an important validation case motivating broader use of CFD in optimizing process and equipment design. A critical component of the freeze drying system is the chamber to pressure duct. A well designed duct, apart from providing smooth flow and lower chamber pressures, should be able to accommodate the peak flow rates without the possibility choking. Here we use computational fluid dynamics as a tool to predict the minimum controllable chamber pressure, maximum sublimation rate, the onset of choking and to suggest better freeze dryer geometry. The main findings include an improved performance concept (IPC) that allowed 11\% improvement in the sublimation rate. The IPC offered a lower minimum controllable pressure at all sublimation rates. A maximum projected improvement because of the combined effect of lower controllable pressure and improved flow throughput is estimated at 14.7\% for the IPC. For the lower condenser temperature, the maximum performance improvement of 8\% was observed at the 50mTorr chamber pressure. Heat transfer to the product is one of the most inefficient step in the Freeze Drying process. While a higher product temperature ensures faster sublimation, it is necessary to maintain it below the collapse temperature for product stability. A quick and reasonable accurate model could accelerate the process design cycle or at the least reduce the number of experimental runs required. Here we present a simplified unsteady heat and mass-transfer model which can be adapted for different equipments and product geometry. The model is compared against experiments, the effect of slice geometry is discussed and the application in a continuous freeze dryer is demonstrated. The model was found to accurately predict the product temperature. However the sublimation rate predictions deviated considerably form experiential studies. It is speculated that the porous structure of the dried cake could play a significant role in the sublimation rates and hence a more complicated model might be required for accurate predictions

A Study on the Impact of Locality in the Decoding of Binary Cyclic Codes

In this paper, we study the impact of locality on the decoding of binary cyclic codes under two approaches, namely ordered statistics decoding (OSD) and trellis decoding. Given a binary cyclic code having locality or availability, we suitably modify the OSD to obtain gains in terms of the Signal-To-Noise ratio, for a given reliability and essentially the same level of decoder complexity. With regard to trellis decoding, we show that careful introduction of locality results in the creation of cyclic subcodes having lower maximum state complexity. We also present a simple upper-bounding technique on the state complexity profile, based on the zeros of the code. Finally, it is shown how the decoding speed can be significantly increased in the presence of locality, in the moderate-to-high SNR regime, by making use of a quick-look decoder that often returns the ML codeword.Comment: Extended version of a paper submitted to ISIT 201

REVIEW OF KERALA REAL ESTATE (REGULATION AND DEVELOPMENT) RULE 2018

This paper surfaces through the Kerala Real Estate (Regulation and Development) Rule passed in 2018 by Kerala Government. Real Estate (Regulation & Development) Act was passed in 2016 by Government of India. As per the Act, States has to setup Real Estate Regulatory Authority. In this paper, we are reviewing the rule passed by the Kerala Government in accordance with the RE ACT passed by the Government of India and the functioning of Kerala Real Estate Regulatory Authority. Keywords: Real Estate, Real Estate Regulatory Authority, Keral

Detecting Dark Matter Annihilation with CMB Polarization : Signatures and Experimental Prospects

Dark matter (DM) annihilation during hydrogen recombination (z ~ 1000) will alter the recombination history of the Universe, and affect the observed CMB temperature and polarization fluctuations. Unlike other astrophysical probes of DM, this is free of the significant uncertainties in modelling galactic physics, and provides a method to detect and constrain the cosmological abundances of these particles. We parametrize the effect of DM annihilation as an injection of ionizing energy at a rate e_{dm}, and argue that this simple "on the spot'' modification is a good approximation to the complicated interaction of the annihilation products with the photon-electron plasma. Generic models of DM do not change the redshift of recombination, but change the residual ionization after recombination. This broadens the surface of last scattering, suppressing the temperature fluctuations and enhancing the polarization fluctuations. We use the temperature and polarization angular power spectra to measure these deviations from the standard recombination history, and therefore, indirectly probe DM annihilation. (abridged)Comment: 13 pages, 8 figures, submitted to PR