Numerical Model Studies on Coastal Processes in a Critically Eroding Sector of South West Coast of India

Source: ICHE Conference Archive - https://mdi-de.baw.de/icheArchiv

Synthesis, spectral, thermal and electrochemical studies of oxomolybdenum(V) and dioxomolybdenum(VI) complexes of an azo dye derived from 4-amino-2,3-dimethyl-1-phenyl pyrazol-5-one

1787-1792Some novel complexes of oxomolybdenum(V) and dioxomolybdenum(VI) with an azodye derived from 4-amino-antipyrine and 3-methoxyphenol have been synthesised and characterized by elemental analyses, molar conductance values, magnetic susceptibility measurements, IR, electronic, ESR, and ¹H NMR spectra and cyclic voltammetric studies. The physico-chemical studies and spectral data indicate that the ligand acts as neutral bidentate. All the complexes are found to be monomeric and neutral with distorted octahedral geometry. The X-ray diffraction studies of [MoO(MOPAAP)Cl₃] and [MoO₂(MOPAAP)Cl₂] indicate that the complexes are orthorhombic with the unit cell dimensions a = 7.3277 Å, b = 9.6663Å and c = 15.8897 Å; and a = 8.5534 Å, b = 9.5986 Å, c = 15.4056 Å respectively.. The CV profile of the complex [MoO(MOPAAP)Cl₃] shows a quasireversible peak, which indicates that the metal-ligand linkage is more covalent in nature. The thermal stabilities of the complexes have been compared and show that [MoO(MOPAAP)Cl₃] is more stable than [MoO₂(MOPAAP)Cl₂]

Comparative evaluation of erosion accretion criteria for a tropical beach

1135-1139Beach processes along the Neendakara-Kayamkulam sector on the coast of Kerala related to the offshore waves and local wind conditions are investigated. This study is based on the field observations made during March 2012 to March 2013, which indicates that a major portion of the beach is dynamically stable except for a few hot spot locations, wherein, the natural balance or equilibrium has been disturbed due to excessive mining or introduction of hard structures as a part of harbour development activities or shore protection measures. It is also observed that the condition of some of the areas which were under heavy erosion during the last decade has improved considerably or remained more or less stable in recent past probably due to the protection measures adopted.</span

Shoreline changes and reef strengthening at Kavaratti island in Lakshadweep Archipelago - A case study

1140-1144The Lakshadweep islands experience severe coastal erosion problem every year due to high monsoonal wave activity. Majority of the islands in the group are surrounded by a reef on the western part which acts as a first line defence for the incoming waves. It was documented from many earlier studies that the reef height in many of these islands has decreased due to both natural and human activities. In many of the islands in the group the widening of entrance channel has been carried out by cutting reef edge as early as in 1971 resulting in high waves entering the lagoonal coast causing high erosion at certain stretches of the island coast. In this paper we are presenting the Kavaratti Island as a case study through systematic collection of beach profiles and monitoring of littoral environment observations for waves and currents. Further, an attempt has also been made for a feasibility study of reconstruction of part of the reef (~400 m length) on the northern part of the island through numerical modelling studies which indicates that the reef strengthening would stabilize the beach. Adopting suitable remedial measures to allow free movement of trapped sediments could be an environment friendly soft measure that would further improve the condition of the island coastline.</span

Stability of laminated composite plates subjected to various types of in-plane loadings

The aim of the present investigation is to examine the stability characteristics of laminated plates subjected to various types of in-plane loadings. Towards this, a rectangular four node finite element, having fourteen degrees of freedom per node, based on a simple higher-order shear deformation theory is developed. The theory employed herein involves four dependent variables. The element is found to be free of shear lock problems. A series of numerical problems are solved to study the effect of various parameters such as lay-up, side to thickness ratio, aspect ratio, type of loadings (uniaxial/biaxial/positive and negative shear/tension-compression/compression-tension) and boundary conditions. Some interesting observations regarding the considerable difference in the buckling resistance of angle-ply plates when subjected to positive and negative shear loading are made

Management Of Shoreline Morphological Changes Consequent To Breakwater Construction

54-61The coastal stretch from Veli to Varkala along Thiruvananthapuram coast, which was in dynamic equilibrium, has two identifiable sediment cells separated by the Muthalapozhi inlet with harbour breakwaters on either side of the inlet. Construction of breakwaters to develop a fishing harbour at Muthalapozhi has caused erosion immediately north of the inlet and beach build up south of the inlet. In addition, the harbour mouth gets blocked due to deposition of sand, virtually making the harbour unusable. In the present study, the processes of shoreline morphological changes along the high energy coast are analyzed using numerical models to propose management options to tackle morphological modifications. Shoreline changes, nearshore processes and beach characteristics along this sector are studied through extensive field observations. The data is used to calibrate and validate sediment transport and shoreline change models for this coast. Sediment transport and shoreline changes are simulated using different modules of LITPACK model. The LITDRIFT module is used to calculate annual sediment transport. The LITLINE module is used for shoreline evolution during fair season and the behaviour of coast during monsoon is simulated using the module LITPROF. The calibration of the model is done with field observations. It is found that beach sediments get deposited on southern side of the breakwater and bypassed sediment gets deposited at the inlet mouth. The model after validation is used to simulate the processes with different designs and a groin field of smaller transitional lengths comparable with the surf zone width. The groins having lengths 40, 30 and 20 m at 120, 220 and 300 m south of breakwater, has been found best suited to control the chocking of harbour mouth due to sediment deposition during beach building period

IFN regulatory factor 3 balances Th1 and T follicular helper immunity during nonlethal blood-stage Plasmodium infection

Differentiation of CD4Th cells is critical for immunity to malaria. Several innate immune signaling pathways have been implicated in the detection of blood-stageparasites, yet their influence over Th cell immunity remains unclear. In this study, we usedreactive TCR transgenic CD4T cells, termed PbTII cells, during nonlethalAS and17XNL infection in mice, to examine Th cell development in vivo. We found no role for caspase1/11, stimulator of IFN genes, or mitochondrial antiviral-signaling protein, and only modest roles for MyD88 and TRIF-dependent signaling in controlling PbTII cell expansion. In contrast, IFN regulatory factor 3 (IRF3) was important for supporting PbTII expansion, promoting Th1 over T follicular helper (Tfh) differentiation, and controlling parasites during the first week of infection. IRF3 was not required for early priming by conventional dendritic cells, but was essential for promoting CXCL9 and MHC class II expression by inflammatory monocytes that supported PbTII responses in the spleen. Thereafter, IRF3-deficiency boosted Tfh responses, germinal center B cell and memory B cell development, parasite-specific Ab production, and resolution of infection. We also noted a B cell-intrinsic role for IRF3 in regulating humoral immune responses. Thus, we revealed roles for IRF3 in balancing Th1- and Tfh-dependent immunity during nonlethal infection with blood-stageparasites