Analysis of Groyne Placement on Minimising River Bank Erosion

AbstractBank erosion is the wearing away of the banks of a stream or river. Impacts of river bank erosion are multifarious: social, economic, health, education and sometimes political. Groynes are structures constructed in rivers to protect the shore. Groynes are generally made of wood, concrete, or rock piles etc. In the present study coir geotextiles in the form of cocologs are used as the groynes to make the groyne more ecofriendly. Study mainly concentrates on analysing the effects of placing groynes at different angles from 450 to 1350 and to find the most effective arrangement for minimising the erosion. Results indicate that cocolog-groynes are effective in minimizing the erosion and protecting the bank. Maximum protection is observed for groyne angle of 1350

Multiple plasmon resonances in naturally-occurring multiwall nanotubes: infrared spectra of chrysotile asbestos

Chrysotile asbestos is formed by densely packed bundles of multiwall hollow nanotubes. Each wall in the nanotubes is a cylindrically wrapped layer of $Mg_3 Si_2 O_5 (OH)_4$. We show by experiment and theory that the infrared spectrum of chrysotile presents multiple plasmon resonances in the Si-O stretching bands. These collective charge excitations are universal features of the nanotubes that are obtained by cylindrically wrapping an anisotropic material. The multiple plasmons can be observed if the width of the resonances is sufficiently small as in chrysotile.Comment: 4 pages, 5 figures. Revtex4 compuscript. Misprint in Eq.(6) correcte

Determination of dynamical ages of open clusters through the A⁺ parameter - II

Blue straggler stars (BSS), one of the most massive members of star clusters, have been used for over a decade to investigate mass segregation and estimate the dynamical ages of globular clusters (GCs) and open clusters (OCs). This work is an extension of our previous study, in which we investigated a correlation between theoretically estimated dynamical ages and the observed values, which represent the sedimentation level of BSS with respect to the reference population. Here, we use the ML-MOC algorithm on Gaia EDR3 data to extend this analysis to 23 OCs. Using cluster properties and identified members, we estimate their dynamical and physical parameters. In order to estimate the A+rh values, we use the main sequence and main sequence turnoff stars as the reference population. OCs are observed to exhibit a wide range of degrees of dynamical evolution, ranging from dynamically young to late stages of intermediate dynamical age. Hence, we classify OCs into three distinct dynamical stages based on their A+rh relationship to Nrelax and Nrelax. NGC 2682 and King 2 are discovered to be the most evolved OCs, like Family III GCs, while Berkeley 18 is the least evolved OC. Melotte 66 and Berkeley 31 are peculiar OCs because none of their dynamical and physical parameters correlate with their BSS segregation levels

Serializing the Parallelism in Parallel Communicating Pushdown Automata Systems

We consider parallel communicating pushdown automata systems (PCPA) and define a property called known communication for it. We use this property to prove that the power of a variant of PCPA, called returning centralized parallel communicating pushdown automata (RCPCPA), is equivalent to that of multi-head pushdown automata. The above result presents a new sub-class of returning parallel communicating pushdown automata systems (RPCPA) called simple-RPCPA and we show that it can be written as a finite intersection of multi-head pushdown automata systems

Present status of exploitation of fish and shellfish resources: Marine fish production of maritime states Of the west coast of India

To highlight the fishery in monsoon, an attempt has been made In this paper to evaluate the impad of monsoon fishing on the exploited marine fish stocks in the west coast of India and the trends In the production of various group in different seasons discussed. Except in Kerala where monsoon fishing is intensive due to the Mud Bank fishery and trawling off Sakthlkulangara and Kochi, in the rest of the coast fishing adivitics are not as intensive as in Kerala during monsoon. The major gears used during monsoon are trawls and ring seines in Keral

Use of Cone-Beam Computed Tomography in the Diagnosis and Treatment of an Unusual Canine Abnormality

Diagnosis and treatment planning are important for successful endodontic treatment. We report a 24-year old male who presented to the Government Dental College in Kozhikode, Kerala, India, in 2015 with pain in his right upper canine. A digital periapical radiograph indicated the presence of a supernumerary tooth superimposing the root of the canine. However, cone-beam computed tomography (CBCT) confirmed that the supernumerary tooth was an illusion and that the canine root had a sharp invagination involving the labial and pulpal dentin surfaces, with evidence of periapical bone destruction. A blunt resection was performed at the level of the invagination and the resected end was filled with a dentin substitute. At a one-year follow-up, the patient was asymptomatic and the periapical region appeared to be healing well. This report highlights the importance of CBCT in visualising abnormal canine morphology, thus allowing appropriate endodontic treatment

Do Alterations in the Rate of Gastric Emptying after Injection Sclerotherapy for Oesophageal Varices Play any Role in the Development of Portal Hypertensive Gastropathy?

Bleeding from portal hypertensive gastropathy (PHG) has been estimated to account for upto 30% of all upper gastrointestinal haemorrhage in patients with cirrhosis and portal hypertension. Although portal hypertension seems to be an essential prerequisite, the precise mechanisms responsible for the development of PHG are unknown. The aim of this study was to examine the role of injection sclerotherapy of oesophageal varices in the development of PHG. Gastric emptying was studied using a radionuclide test meal with the emptying characteristics of a slow liquid in 57 patients with cirrhosis and/or portal hypertension (median age 53 yrs), of whom 34 had received injection sclerotherapy for their oesophageal varices and 20 normal healthy volunteers (median age 42 yrs). As vagal damage is associated with more rapid emptying of liquids, despite hold up of solids, this technique might be expected to demonstrate such damage if gastric emptying was accelerated. The results indicated that there was no difference in the rate of gastric emptying between normal healthy volunteers and portal hypertensive patients. However, patients who had received injection sclerotherapy emptied their stomachs faster than those who had not (p<0.05). Furthermore, the speed of gastric emptying correlated directly with the number of injections (r=0.41; p=0.02) and the volume of sclerosant injected (r=0.39; p=0.03). These observations suggest that injection sclerotherapy for oesophageal varices results in disturbances of gastric emptying that may contribute to the pathogenesis of portal hypertensive gastropathy

Evolution of the macromolecular structure of sporopollenin during thermal degradation

AbstractReconstructing the original biogeochemistry of organic microfossils requires quantifying the extent of the chemical transformations they experienced during burial and maturation processes. In the present study, fossilization experiments have been performed using modern sporopollenin chosen as an analogue for the resistant biocompounds possibly constituting the wall of many organic microfossils. Sporopollenin powder has been processed thermally under argon atmosphere at different temperatures (up to 1000 °C) for varying durations (up to 900 min). Solid residues of each experiment have been characterized using infrared, Raman and synchrotron-based XANES spectroscopies. Results indicate that significant defunctionalisation and aromatization affect the molecular structure of sporopollenin with increasing temperature. Two distinct stages of evolution with temperature are observed: in a first stage, sporopollenin experiences dehydrogenation and deoxygenation simultaneously (below 500 °C); in a second stage (above 500 °C) an increasing concentration in aromatic groups and a lateral growth of aromatic layers are observed. With increasing heating duration (up to 900 min) at a constant temperature (360 °C), oxygen is progressively lost and conjugated carbon–carbon chains or domains grow progressively, following a log-linear kinetic behavior. Based on the comparison with natural spores fossilized within metasediments which experienced intense metamorphism, we show that the present experimental simulations may not perfectly mimic natural diagenesis and metamorphism. Yet, performing such laboratory experiments provides key insights on the processes transforming biogenic molecules into molecular fossils

Experimental study using coir geotextiles in watershed management

International audienceThis paper presents the results of a field experiment conducted in Kerala, South India, to test the effectiveness of coir geotextiles for embankment protection. In the context of sustainable watershed management, coir is a cheap and locally available material that can be used to strengthen traditional earthen bunds or protect the banks of village ponds from erosion. Particularly in developing countries, where coir is abundantly available and textiles can be produced by small-scale industry, this is an attractive alternative for conventional methods

Asymptomatic bacteriuria among antenatal women attending a tertiary care hospital in Kanchipuram: evaluation of screening tests and antibiotic susceptibility pattern

Background: Asymptomatic bacteriuria (ASB) occurring in pregnant women can lead onto complications like acute pyelonephritis, hypertensive disease of pregnancy, premature delivery and intrauterine growth retardation if untreated.Methods: The present study aims to estimate the occurrence of asymptomatic bacteriuria in antenatal women and to study the antibiotic susceptibility pattern of the isolates. The Gram staining, pus cell count and culture was performed for 120 urine samples. Antibiotic susceptibility testing was done by Kirby Baeur disk diffusion method. MRSA (Methicillin resistant Staphylococcus aureus) and ESBL (Extended spectrum Beta Lactamases) producers were identified by Standard guidelines. The   sensitivity, specificity, negative predictive values and positive predictive values of Gram staining and pus cell count was calculated.Results: Out of the 120 samples 14 (11.66%) were positive for asymptomatic bacteriuria. The Gram staining showed specificity and negative predictive value of 95.2% and 98.1% respectively. Pus cell count showed a specificity and negative predictive value of 96.29% and 98.11% respectively. Escherichia coli were the predominant species isolated 5 (35.7%). Among the gram negative bacteria, amikacin and nitrofurantoin showed a susceptibility of 90% and 80% each. All the staphylococcus aureus isolates showed 100% sensitivity for nitrofurantoin.  Two Klebsiella spp and one Escherichia coli isolate were identified as ESBL producers. Among the S. aureus isolates 3 were identified as Methicillin resistant (MRSA).Conclusions: Urine culture should be performed for all pregnant women irrespective of the symptoms and should be treated promptly to prevent the complications arising out of ASB.