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• The synthesis of Ni 0.5 Zn 0.5 Fe 2 O 4 nanoparticles (NPs) by combustion method. • To estimate electronic polarizability using Clausius-Mossotti and Penn analysis. • The NPs exhibited multi-photon absorption and self-defocusing nature. • Industrial uses of prepared NPs should focus on optical switching. In this article, Ni 0.5 Zn 0.5 Fe 2 O 4 nanoparticles (NPs) were synthesized via microwave-assisted combustion method. XRD investigation indicates the cubic spinel structure. At ambient temperature, the dielectric constant and loss were determined by modulating the applied frequency (50 Hz to 200 kHz). The calculated third-order NLO susceptibility (χ(3)) was found for glycine (2.385 × 10-6 esu), urea (0.9696 × 10-6 esu) and citric acid (2.755 × 10-6 esu). However, this work reveals that synthesized NPs have high convenience for optoelectronic, optical switching, and limiting applications. [ABSTRACT FROM AUTHOR]

In this study, Ni1−xZnxFe2O4 (x = 0, 0.25, and 0.5) nanoparticles were successfully synthesized via microwave-assisted combustion method and characterized by XRD, FTIR, and SEM–EDAX. XRD results enunciate that the nanoparticle crystallizes in cubic spinel structure with an average crystallite size (40.2, 37.2, 35.1 nm), and also, the lattice strain, specific surface area, X-ray density were evaluated. The morphology and chemical compositions of Ni, Zn, Fe, and O elements were confirmed by the SEM–EDAX studies. For all the samples, vibrational stretching modes of Mtetra–O site (597 (S1), 593 (S2), 583 (S3) cm−1) and Moctra–O site (416 (S1), 421 (S2), 422 (S3) cm−1) were related to the distribution of the cation Ni2+/Zn2+ and Fe3+ ions among the octahedral and tetrahedral sites. From the UV–Vis–DRS spectra, the optical energy band gap has been estimated to be 1.75–2.01 eV. The dielectric constant and loss were measured by varying the applied frequency (50 Hz to 200 kHz) at room temperature. The electronic polarizability (α) was calculated using Penn analysis, Clausius–Mossotti equation, and energy band gap value. Third-order nonlinear optical parameters such as the nonlinear absorption coefficients (10−5 cm/W), refractive index (10−9 cm2/W) and the third-order nonlinear susceptibilities (10−6 esu) were determined by Z-scan technique. The antibacterial studies were tested against Bacillus cereus, Staphylococcus aureus, Shigalla flexneri and Klebsiella pneumonia bacterial strains. The existing results point out that the synthesized Ni/Zn/Fe2O4 nanoparticles are possible candidates for photonic devices, optical switches, optical limiting and also for pharmaceutical applications. [ABSTRACT FROM AUTHOR]

An organic nonlinear optical (NLO) single crystal of L-methioninium picrate (LMP) has been grown by slow evaporation solution technique (SEST) at a constant temperature of C. Formation of nucleation and growth kinetics of the crystal were observed using an optical microscope for different durations and it was found that the shape of nucleation is similar to the grown large size single crystals of the same material. The characterization techniques such as powder X-ray diffraction (PXRD) analysis, UV-Vis NIR, Vickers microhardness, piezoelectric d coefficient, photoconductivity and etching studies have been performed. The crystal system and lattice parameters of the grown crystal were determined by PXRD analysis. The spectroscopic properties of the synthesized compound were confirmed by Fourier transform infrared (FTIR) analysis. The UV-Vis NIR analysis was performed on the grown single crystal to find the optical absorption in the entire visible region. Attempts have been made to investigate the mechanical properties of LMP crystal using Vickers diamond pyramid indenter. In addition piezoelectric, photoconductivity and etching studies were carried out to study the d coefficient, photoconducting nature and surface properties respectively. [ABSTRACT FROM AUTHOR]

Organic nonlinear optical (NLO) single crystal of L-tartaric acid-nicotinamide (LTN) has been grown by slow evaporation solution technique at a constant temperature of 40C. The grown crystals were subjected to various characterization techniques in order to examine their suitability for various applications. Powder X-ray diffraction (PXRD) analysis revealed that the compound is formed without any impurities. Functional groups and formation of the title compound were confirmed using FTIR analysis. Optical behavior of the material was examined using UV-Vis NIR spectrum analysis and the lower cut-off wavelength and optical band gap energy were calculated. Microhardness, dielectric and piezoelectric studies have been carried out at ambient conditions. Electronic properties such as valence electron plasma energy, Penn gap, Fermi energy and electronic polarizability were calculated by Clausius-Mossotti relation. Photoluminescence analysis was carried out to study the luminescence nature of the crystal and its defect states. In addition photoconductivity, etching studies and powder Kurtz and Perry second harmonic generation (SHG) test were carried out. [ABSTRACT FROM AUTHOR]

Recently, we have performed systematic Secondary Ion Mass Spectrometry (SIMS) measurements at our ion source test set up and have demonstrated that gas phase 32 SF n − ( n = 1–6) anions for all size ‘ n ’ can be readily generated from a variety of surfaces undergoing Cs + ion sputtering in the presence of high purity SF 6 gas by employing the gas spray-cesium sputter technique. In our SIMS measurements, the isotopic yield ratio 34 SF n − / 32 SF n − ( n = 1–6) was found to be close to its natural abundance but not for all size ‘ n ’. In order to gain further insight into the constituents of these molecular anions, ultra sensitive Accelerator Mass Spectrometry (AMS) measurements were conducted with the most abundant 32 SF n − ( n = 1–6) anions, at BARC-TIFR 14 UD Pelletron accelerator. The results from these measurements are discussed in this paper. [ABSTRACT FROM AUTHOR]

Track etch membranes (TEMs) program at 14 UD Pelletron accelerator at TIFR, Mumbai, India using 25 micron thick polyethylene terepthalate film is described. Large scale preparation of TEMs by scanning heavy ion beams using a electromagnetic scanner and rolling mechanism using a geared D.C. motor and vacuum rotary feed through are presented. The selection of ions of suitable energy and etching parameters for making various pore sizes were investigated using Rutherford scattered beam from Pelletron accelerator. Pore size and pore density were measured using scanning electron microscope. Scanning width up to 35 cm and irradiation up to 22 m were successfully carried out using this facility. Some applications carried out using these membranes are also mentioned. [ABSTRACT FROM AUTHOR]

Aims: The genetic diversity of Vibrio cholerae isolated from black tiger shrimp ( Penaeus monodon) aquaculture farms was determined using three PCR typing methods based on enterobacterial repetitive intergenic consensus (ERIC) sequences, ribosomal gene spacer (RS) sequence and repetitive extragenic palindromic (REP) sequences. Methods and Results: Non-O1 and non-O139 V. cholerae isolates were obtained from shrimp pond water, pond sediment, shrimp head and shrimp muscle. RS-PCR yielded fewer bands than REP-PCR and ERIC-PCR. Higher similarity was observed in RS-PCR (75–100%) than in REP-PCR (60–95%) and ERIC-PCR (40–95%). Conclusions: A 100% similarity between V. cholerae isolates was only noticed in RS-PCR. The choleratoxigenic V. cholerae (non-O1 and non-O139) showed greater genetic similarity with ctx-negative V. cholerae than among ctx-positive V. cholerae. Significance and Impact of the Study: The greater similarity of ctx-positive V. cholerae with ctx-negative V. cholerae isolates indicates that the ctx-positive strains (non-O1 and non-O139) might have originated from autochthonous V. cholerae in the aquatic niche. [ABSTRACT FROM AUTHOR]

Abstract: The accelerator mass spectrometry programme and the related developments based on the BARC–TIFR Pelletron accelerator is described. A segmented gas detector and beam chopper control electronics have been developed for conducting 36Cl measurements. Distinct energy loss characteristics of the gas detector and beam chopper performance are presented. Also presented are the initial results for the measurement of 36Cl in standard and samples of unknown concentration. [Copyright &y& Elsevier]

Background & objectives: Bacillus cereus is an important enterotoxigenic food borne pathogen. The present study was undertaken to assess the occurrence of B. cereus in tropical fish and evaluation of virulent gene specific PCR for differentiation of diarrhoeal enterotoxin producing isolates of B. cereus from non enterotoxigenic isolates. Methods: Selective plating on polymixin-pyruvate-egg yolk-mannitol-bromocresol purple agar (PEMPA) was used for isolation of B. cereus from finfish, prawn and clams. Enterotoxin producing ability of all 42 isolates obtained from the samples was judged by reverse passive latex agglutination (RPLA) test and the presence of different virulent genes i.e. hbla, bceT and entFM was screened by PCR. Results: B. cereus and enterotoxigenic B. cereus were found to be in 36.7 and 29.41 per cent of fish samples, respectively. All the diarrhoeal enterotoxin producing isolates showed the presence of hbla gene, but hbla gene was not present in any of the non-enterotoxigenic isolates tested in this study. Interpretation & conclusions: Our findings indicated that hbla gene specific PCR can be employed for differentiation of enterotoxigenic B. cereus isolates from non-enterotoxigenic isolates. [ABSTRACT FROM AUTHOR]

Aims: To determine the distribution of Salmonella serovars in seafood and to examine the intraserovar genetic variations in Salmonella enterica subsp. enterica serovar Rissen and Salmonella Weltevreden by polymerase chain reaction (PCR)-ribotyping and enterobacterial repetitive intergenic consensus (ERIC)-PCR methods. Method and Results: A total of 417 seafood samples collected over 2003–2006 from fishing harbours and fish markets of Cochin (India) was studied for presence of Salmonella serovars. Seafood samples were analysed for the presence of Salmonella by Bacteriological Analytical Manual (BAM), U.S. Food & Drug Administration (USFDA) method. The study indicated that 23·2% of the seafood samples were positive for Salmonella and a total of 241 Salmonella isolates comprising of 27 different serovars were isolated from seafood. S. Weltevreden, Salmonella Rissen, Salmonella Typhimurium and Salmonella Derby were found to be the most predominant serovars in seafood. PCR-ribotypes and ERIC-PCR profiles showed multiple genotypic profiles for S. Rissen and S. Weltevreden in seafood and the level of discrimination indices obtained was at 0·974 for S. Rissen and 0·988 for S. Weltevreden, respectively. Conclusion: The study highlighted the major Salmonella serovars in the seafood of Cochin (India) and molecular fingerprinting pattern revealed genetic variation among S. Rissen and S. Weltevreden. Significance and Impact of the Study: Widespread occurrence of Salmonella contamination in seafood and multiple clones of S. Rissen and S. Weltevreden detected in seafood, thus, indicated the diverse routes of Salmonella contamination in seafood. [ABSTRACT FROM AUTHOR]

The objective of this study was to determine the microbiological quality of farmed giant freshwater prawn (Macrobrachium rosenbergii) collected from four freshwater farms located in Kerala (India). Microbiological counts on whole, deheaded, and deheaded and deveined prawn as well as on head and intestine were determined. Average counts (log10 cfu g-¹) on whole prawn were 6.9 (total mesophilic counts (TPC) at 37°C) and 4.1 (psychrotrophic count at 7°C). The results indicated that the aerobic counts were within the acceptable limit. The levels of enterococci and faecal coliforms in farmed M. rosenbergii were high. There was an increase in the numbers of enterococci and Staphylo- coccus aureus after deheading. The major groups of bacteria comprising the flora of M. rosenbergii were Aeromonadaceae, Enterobacteriaceae and Pseudo,nonas. Farmed M. rosenbergii carried pathogenic bacteria such as Enterococcus spp., S. aureus, Aeromonas hydrophila, A. veronii biovar sobria and Clostridium perfringens. The results of the study sug- gest adoption of good farming and post harvest practices to improve the microbiological quality of farmed freshwater prawn. [Article copies available [ABSTRACT FROM AUTHOR]

• Carbon quantum dots (CQDs) were synthesized from Ananas comosus using a cost-effective green technique. • CQDs exhibit blue emission under an excitation wavelength of 365 nm. • Investigation of third-order NLO properties of prepared CQDs by Z-scan technique. • The high figure of merit (W and T) shows an effective optical switching application. • CQDs are effective antibacterial activity and antioxidant assay for selected clinical pathogens. Carbon quantum dots (CQDs) were synthesized from agro-waste Ananas comosus by facile hydrothermal treatment. The synthesize CQDs are characterized by XRD, HRTEM, FTIR, XPS, UV–Visible spectral analysis, and Quantum yield (QY) measurements. The formation of CQDs has a typical particle size of 2.4 ± 0.5 nm which was measured by HR-TEM analysis. The fluorescence properties of CQDs show strong blue emission radiation with a QY of 10.65%. The NLO CQDs exhibit properties of self-defocusing and multi-photon absorbance when exposed to a continuous-wave laser (532 nm, 100 mW). The calculated third-order NLO parameters, like β, n 2 , and χ(3) was obtained to be in the order of 3.0864 × 10-4 cm/W, 8.5137 × 10-9 cm2/W, and 3.2882 × 10-7 (esu), respectively. Antibacterial activities of CQDs were screened against (S. aureus, B. cereus, E. coli, P. aeruginosa, and V. cholera) microbial organisms and Antioxidant assay of the CQDs was assessed against the DPPH method. Furthermore, the synthesized CQDs will be applicable to NLO devices and pharmaceutical applications. [ABSTRACT FROM AUTHOR]

• Nonlinear optical nanoparticles of Ni/Zn/Fe 2 O 4 were synthesized by microwave assisted combustion method with different fuel to oxidizer ratio. • Luminescence emission spectra were carried out to analyse the luminescence nature of the material. • Higher values of dielectric constant and loss suggest that the synthesized nanoparticles can be used in optoelectronic and NLO applications. • The nonlinear optical parameters of the synthesized nanoparticles were measured by closed and open aperture Z-scan technique using CW laser (100 m W) operated at 532 nm impact on NLO properties due to fuel to oxidizer ratio was carried out. • Antibacterial activity were tested for the first time, against gram-positive and gram-negative bacterial strains. In this article, Ni 0.5 Zn 0.5 Fe 2 O 4 nanoparticles (NPs) were synthesized by differing concentrations of fuel (lean, stoichiometric, and rich) via microwave-assisted combustion route. The effect of fuel content was used to explore their chemical, electrical, and nonlinear optical properties along with their antibacterial activity of the as-prepared Ni/Zn/ferrite NPs were studied. The XRD assures the cubic crystal structure of prepared NPs with no secondary phase. It is also clear that as lattice parameters increases, the mean crystallite size decreases as a change in fuel ratio. The optical energy bandgap values are estimated as 2.88, 3.28, and 3.0 eV, respectively. From the luminescence spectra, the Ni/Zn ferrite NPs exhibits strong green emission and weak violet emission color. The fuel ratio has a significant influence on the electronic polarizability properties of synthesized NPs. Closed and open aperture Z-scan technique reveals that the Ni/Zn ferrites NPs have self-defocusing nature, and reverse saturable absorption. The calculated values are NLA coefficients (10-5 cmW−1), NLR index (10−9 cm2W−1), and third-order NLO susceptibility χ(3) values of fuel lean (1.408 × 10−5 esu), stoichiometric (2.75 × 10−6 esu), and rich (2.634 × 10−5 esu). Several identified microorganisms such as gram + Ve (S. aureus, B. cereus), and gram -Ve (P. aeruginosa, V. cholerae, and E. coli) have been tested for antibacterial activity against Ni/Zn ferrite nanoparticles. The ZOI values are 27 (lean), 24 (stoichiometric), and 25 mm (rich) which suggest great antibacterial activity against Pseudomonas aeruginosa gram-negative bacterium. However, this study shows excellent feasibility of applying prepared ferrite nanoparticles for optoelectronic devices and pharmaceutical processing applications. [ABSTRACT FROM AUTHOR]

A novel ultra-wideband short range radar (UWB-SRR) system for measuring a target maximum range of 15 m and relative velocity of 150 km/h is proposed. The conventional detector has less detection performance if the reflected echo signals from the target are more distributed because the detection performance depends on a particular range bin only. However, the proposed detector's detection performance is increased when the reflected echo signals from the target are combined using the proposed sliding window. According to the presented simulation and theoretical analysis, the proposed detector is superior to conventional detectors when the target echo signal is more distributed against a background of additive white Gaussian noise. [ABSTRACT FROM AUTHOR]

An efficient organic nonlinear optical single crystal of l -arginine maleate dihydrate (LAMD) has been grown by slow evaporation solution technique (SEST) and slow cooling technique (SCT). The crystalline perfection of the crystal was examined using high–resolution X–ray diffractometry (HRXRD) analysis. Photoluminescence study confirmed the optical properties and defects level in the crystal lattice. Electromechanical behaviour was observed using piezoelectric co-efficient (d 33 ) analysis. The photoconductivity analysis confirmed the negative photoconducting nature of the material. The dielectric constant and loss were measured as a function of frequency with varying temperature and vice-versa. The laser damage threshold (LDT) measurement was carried out using Nd:YAG Laser with a wavelength of 1064 nm (Focal length is 35 cm) and the obtained results showed that LDT value of the crystal is high compared to KDP crystal. The high laser damage threshold of the grown crystal makes it a potential candidate for second and higher order nonlinear optical device application. The third order nonlinear optical parameters of LAMD crystal is determined by open-aperture and closed-aperture studies using Z-scan technique. The third order linear and nonlinear optical parameters such as the nonlinear refractive index (n 2 ), two photon absorption coefficient (β), Real part (Reχ 3 ) and imaginary part (Imχ 3 ) of third-order nonlinear optical susceptibility are calculated. [ABSTRACT FROM AUTHOR]

Escherichia coli is a common contaminant of seafood in the tropics and is often encountered in high numbers. The count of E. coil as well as verotoxigenic E. coli O157:H7 was estimated in 414 finfish samples composed of 23 species of fresh fish from retail markets and frozen fish from cold storage outlets in and around Cochin, India. A total of 484 presumptive E. coli were isolated, and their indole-methyl red-Voges-Proskauer-citrate (IMViC) pattern was determined. These strains were also tested for labile toxin production by a reverse passive latex agglutination method and checked for E. coli serotype O157 by latex agglutination with O157-specific antisera. Certain biochemical marker tests, such as methylumbelliferyl-β-glucuronide (MUG), sorbitol fermentation, decarboxylase reactions, and hemolysis, which are useful for screening pathogenic E. coli, were also carried out. Results showed that 81.4% of the E. coli isolates were sorbitol positive. Among this group, 82% were MUG positive, and 14.46% of the total E. coli isolates showed human blood hemolysis. None of the isolates were positive for agglutination with E. coli O157 antisera nor did any produce heat-labile enterotoxin. This study indicates that typical E. coli O157 or labile toxin-producing E. coli is absent in the fish and fishery environments of Cochin (India). However, the presence of MUG and sorbitol-negative strains that are also hemolytic indicates the existence of aberrant strains, which require further investigation. [ABSTRACT FROM AUTHOR]

A 63-year-old male presented with sudden increase in size of a right inguinal swelling which was present for the past 10 years. Clinical diagnosis of inguinal soft tissue mass/lymph node enlargement was made and patient was investigated further for a conclusive diagnosis. Ultrasound examination suggested it to be a lymph node and guided fine needle aspiration cytology was performed. Cytology was suggestive of a reactive lymph node. Subsequently, an excision biopsy was performed that revealed a granular cell tumor with many lymphoid aggregates. On reviewing the cytosmears, we realised that the granular neoplastic cells were mistaken for histiocytes; and the lymphoid background and bare nuclei mislead us to consider it a reactive lymph node. Since granular cell tumor can occur almost anywhere, a careful examination of cytosmears and knowledge of its distinctive cyto-morphological features would be helpful in providing an accurate diagnosis on cytology. [ABSTRACT FROM AUTHOR]

Rice crop, a staple food for a majority of population across the world, holds a significant role to play in alleviating the global hunger problem. Enhancement of genetic diversity of rice will serve to overcome constraints in sustained and ecologically effective improvement in the production of quality rice, challenged by erratic patterns of global climate, changing pest dynamics, resource availability in proportion to growing population etc. Proton ion beam has sprung up as a promising novel mutagen in the mutation breeding of crop plants, by virtue of its higher LET values, causing higher frequency of mutations. Dose optimization is pre-requisite to obtain a range of phenotypic mutants, without drastic reduction in survival and growth subsequently. This study was undertaken to standardize proton beam irradiation dose rate post the evaluation of in-vitro germination, growth and survival of rice variety IBD -1, with doses ranging from 0-500Gy. Doses between 152.47Gy-253.53Gy were found suitable for mutagenesis, without drastically impairing growth and survival. [ABSTRACT FROM AUTHOR]

The excitation functions for reaction residues populated via In 115 ( p , p ) 115 m In, In 115 ( p , p n ) 114 m In, In 115 ( p , p 2 n ) 113 m In, In 113 ( p , p ) 113 m In, In 115 ( p , n α ) 111 m Cd, In 115 ( p , 3 n ) 113 Sn and In 113 ( p , n ) 113 Sn channels were measured over the proton energy range of 8–22 MeV using stacked foil activation technique. Theoretical analysis of the data were performed within the framework of two statistical model codes EMPIRE-3.2 and TALYS-1.8. Isomeric cross section ratio for isomeric pairs In m , g 115 , In m , g 114 , In m , g 113 , S 113 n m , g and Cd m , g 111 were determined for the first time. The dependence of isomeric cross section ratio on various factors are analysed. [ABSTRACT FROM AUTHOR]

Nonlinear optical single crystals of L-lysine p-nitrophenolate monohydrate (LLPNP) were grown in aqueous solution by the slow evaporation solution technique (SEST). The grown crystals were subjected to powder X-ray diffraction analysis, (PXRD) and it was found that the title compound was crystallized in the orthorhombic crystal system with noncentrosymmetric space group of 212121. The vibrational frequencies of various functional groups present in the crystal were analyzed using the FTIR spectrum with a wavenumber range between 450 cm and 4000 cm. The microhardness analysis of the sample revealed that the crystal belongs to the soft material category. Piezoelectric analysis was performed to measure the value of the piezoelectric (d) coefficient. Blue light emission of the material was confirmed using the photoluminescence spectrum. Thermal stability of the grown crystal was analyzed using a melting point apparatus and it was found that the LLPNP is stable upto 175C. Etching analysis was performed at various durations, in order to identify the surface properties of the LLPNP crystal. [ABSTRACT FROM AUTHOR]

Organic single crystal of nicotinium tartrate (NT), an efficient nonlinear optical (NLO) material for frequency conversion, has been grown at a constant temperature at 40C within a period of 20 days by slow evaporation solution technique (SEST). Structural information and lattice dimensions were determined using powder X-ray diffractometer (PXRD) analysis. The functional groups and vibrational frequencies were identified using FTIR spectrum analysis with the range of 4000-450cm. Mechanical properties of the grown crystal were studied using Vickers microhardness tester. The optical properties of grown crystal were investigated using UV-Vis NIR spectrum analysis and it is confirmed that the crystal has very low absorption in the entire visible region. The dislocations and defects were studied by photoluminescence spectrum. The crystal has single stage melting, which was observed at 180C and there was no decomposition before its melting point. Piezoelectric, photoconductivity and chemical etching analysis have also been performed on the grown NT single crystals and the observed results were discussed. Nonlinear optical property of the material was measured using the powder Kurtz-Perry technique. [ABSTRACT FROM AUTHOR]

The yield of R 105 u and R 105 h produced through proton induced fission of U 238 are measured using stacked foil activation technique. The results are compared with theoretical calculations using TALYS 1.95. As the R 105 h shows a higher cross-section for neutron absorption in the thermal region, production of this isotope will act as a reactor poison. Hence the reactivity equivalent of R 105 h is also calculated and is found to be −0.84%. [ABSTRACT FROM AUTHOR]

The article presents a case study of a 19-year-old male who complained of hair in the oral cavity since 2 months. He had a slow growing mass in the mandible for the past 7 years. A biopsy was conducted on the patient and he was later diagnosed with ameloblastoma. He later complained of hair growth in the grafted site after the surgery. It notes that ameloblastoma is one of the most common odontogenic tumors, which accounts for only 1% of all oral tumors.

White spot syndrome virus (WSSV) is the causative agent of a disease that causes severe mortalities in cultured shrimp worldwide. The sequence of five structural genes of an Indian isolate of WSSV was compared with sequences from other WSSV isolates deposited in GenBank. Among the structural genes analyzed, the sequences of vp28 and vp19 had maximum divergence with nucleotide changes at ten different positions from twenty eight submissions for vp28 and six changes from seventeen submissions for vp19. The vp68, vp26, and vp281 genes were found to be highly conserved between isolates. [ABSTRACT FROM AUTHOR]

In the present work, a room temperature chemical etching (RTCE) method has been explored for controlled development of pores in the chlorine ions (115 MeV) bombarded polyethylene terepthalate (PET) (25 μm) sheets. In this pore development method, a mixture of ethanolamine and NaOH is employed. The pore-size distributions in thus formed PET track-etched membranes have been obtained by the capillary flow porometry, and compared with the results of PET track-etched membranes subjected to widely used chemical etching (CE) at elevated temperature. Multiple pore size distributions have been observed with the CE method. However, with RTCE, pores with single narrow pore size distribution have been observed. To further improve the RTCE method, the chlorine ions bombarded PET sheets have been sensitized with UV radiation (254 nm) for 1 h, and subjected to RTCE. The average pore-size has been found to increase with UV-sensitization without affecting the nature of pore-size distribution, indicating the possibility of formation of the track-etch membranes with different pore sizes. Track etching studies show that both bulk-etch and track-etch rates increase in RTCE with respect to the conventional chemical etching. The ratio of the track-etch rate to bulk-etch rate governs the shape of the pores. The conical shaped pores with small cone angles are observed when track-etch rate is significantly higher than the bulk-etch rate. However, in the present case, V T is observed to be not very much greater than V B ( V T / V B <100), showing the formation of double bowl pores or conical pores with large cone angles. This has been confirmed by the FEG-SEM observations. [ABSTRACT FROM AUTHOR]

• Carbon Steel pipe corrosion in 50NB Sch 160 of bend angle 58° radius 4 times diameter. • Specimen welded to HTHP loop irradiated with proton beam for nuclear reaction. • In loop pH (10.2) DO (<5 ppb) at 290 °C/87 bar maintained by adding LiOH and N 2 H 4. • Corrosion rate measured by TLA method. • CFD simulated corrosion rate coincides with that of TLA method. Carbon Steel (CS) piping plays a vital role in the heat transport circuits of power plants. These pipes undergo excessive degradation in some of the specific locations due to the flow dynamics variation and such corrosion is termed as the flow accelerated corrosion (FAC). The corrosion rate is usually estimated at a specific location based on one of the best available technique known as the Think Layer Activation (TLA) method. In the present study this method was adopted for the estimation of CS pipe corrosion with 50NB Sch 160, bend angle of 58° and 4D bend radius (D-pipe diameter). Irradiated location was chosen based on the turbulence patterns in the bend as mapped by CFD analysis. At the specified location the corrosion rate to be monitored was irradiated with the proton beam of 13.3 MeV energy aiming for the nuclear reaction of Fe56(p,n) Co56. This irradiated specimen was welded to the High Temperature High Pressure (HTHP) loop and operated at 290 °C/87 bar. The chemistry parameters like pH (10.2) and DO (< 5 ppb) in the loop were maintained by suitably adding LiOH and N 2 H 4. Corrosion rate was assessed by measuring the radioactivity decrease due to corrosion. Throughout the experimental duration the radioactivity measurement was carried on the CS pipe surface at the fixed distance locations. The flow structure in the considered geometry is simulated using CFD. The flow field, velocity, is used to calculate the wall shear stress and mass transfer coefficient. The corrosion rate is calculated with the help of Chilton-Calbourn Equation. It is observed that the computed corrosion rate for this CS pipe under this chemistry and geometry conditions was 400um/y which coincides with that of the TLA method. [ABSTRACT FROM AUTHOR]