Corrosion of Reinforced Concrete and Its Protection

Concrete is used as construction material in the form of plain or reinforced concrete through out the world. It has to withstand the physical, chemical and environmental effects for fulfilling the durability characteristics. The environmental changes due to pollution, lack of main-tenance, poor quality of work, lack of supervision, use of defective materials etc have also taken a heavy toll of concrete structures. Among various factors affecting the reinforced concrete structures the atmosphere, water, salts are most common factors which play a key role for reinforcement corrosion. The damage due to corrosion is a serious effect upon the mechanical properties of concrete structures. Once the corrosion of reinforcement starts due to formation of oxide and if the structure is under load, the stress act-ing on it increases. In such case the ultimate tensile stress (UTS) exceeds and finally the structure fails. The present paper highlights the corrosion of rein-forced concrete structures, factors influencing corrosion of reinforcement, and its remedial measures to some extent

Lectotypification of names in the genus Eragrostis Wolf (Poaceae)

In the present work 3 names within the genus Eragrostis viz, Eragrostis coarctata, E. plana and E. superba have been typified. Lectotypification has been performed for E. coarctata and Second-step lectotypification has been done for the names E. plana and E. superba. For lectotypification, rules and recommendations proposed by the International Code of Nomenclature for algae, fungi and plants (ICN), have been strictly followed. The selection of lectotypes are explained and the images of selected lectotypes are provided

Awareness about cervical cancer risk factors and symptoms

Background: Lack of awareness of risk factors and symptoms for cancer may leads to late diagnosis and poor prognosis. A Cross-sectional population-based survey was conducted to assess community awareness about cervical cancer risk factors and symptoms and perceptions about prevention and cure of cervical cancer.Methods: The cross-sectional study included 200 married women aged 18 years and above who consented for the study.Results: In present study, out of 200 respondents, the risk factors for cervical carcinoma known to females were HPV infection in 30 (15%), multiparity and reproductive tract infection in 24 (12%) each, frequent childbirth in 22 (11%), early marriage in 18 (9%) and multiple sexual partners in 12 (6%).158 (79%) females knew vaginal bleeding between menses as symptom of cervical cancer. 132 (66%) knew symptom as foul-smelling vaginal discharge, 86 (42%) as lower abdominal pain, 82 (41%) as loss of appetite and weight while 52 (26%) females knew the symptom as postcoital bleeding. 54 (27%) respondents knew that pap smear test should be done as screening test to detect cervical cancer in early stage while 22 (11%) respondents knew about HPV vaccine as preventive measure.Conclusions: Recognition of cervical cancer risk factors and symptoms was low among study participants. Targeted interventions including increasing availability of HPV vaccination, population-based cervical screening and diagnostic services can translate high awareness into actual benefits

Electric Field Assisted Self-Healing of Open Circuits with Conductive Particle-Insulating Fluid Dispersions: Optimizing Dispersion Concentration

Abstract: Open circuit faults in electronic systems are a common failure mechanism, particularly in large area electronic systems such as display and image sensor arrays, flexible electronics and wearable electronics. To address this problem several methods to self heal open faults in real time have been investigated. One approach of interest to this work is the electric field assisted self-healing (eFASH) of open faults. eFASH uses a low concentration dispersion of conductive particles in an insulating fluid that is packaged over the interconnect. The electric field appearing in the open fault in a current carrying interconnect polarizes the conductive particles and chains them up to create a heal. This work studies the impact of dispersion concentration on the heal time, heal impedance and cross-talk when eFASH is used for self-healing. Theoretical predictions are supported by experimental evidence and an optimum dispersion concentration for effective self-healing is identified

A Non aqueous Formulation for Efficient Detoxification of Chemical Weapons at Sub zero Temperatures

An effective decontamination methodology based on nucleophilic non-aqueous decontaminant has been developed against chemical weapons sulfur mustard and soman. This new formulation consists of non-aqueous solution of 2-aminoethanol (60%, w/v), potassium hydroxide (2%, w/v), and N-methyl-2-pyrrolidone (38 %, w/v) and detoxified more than 99 % of sulfur mustard and soman within a period of 30 min at -35 °C. It was found to be operable over a wide range of temperatures starting from -35 °C to +55 °C without losing its fluidity and detoxicant efficiency at sub-zero temperatures promising hassle-free application against chemical weapons. It degrades sulfur mustard to divinyl sulfide and 2-chloroethyl vinyl sulfide and converted soman into O-pinacolyl O’-(2-amino) ethyl methylphosphonate, which are relatively non toxic to humans. This formulation is environmentally benign, relatively non corrosive and has an improved capability to dissolve and decontaminate chemical weapons within 15 minutes at ambient conditions. This approach paves the way for efficient and rapid decontamination platform for chemical weapons and holds considerable promise for field application in near future

Biochemical characterization of thermostable cellulase enzyme from mesophilic strains of actinomycete

A few mesophilic strains of actinomycete were used for detection, extraction and characterization of cellulase enzymes. These strains responded to produce all the three components of cellulase complex (endoglucanase, exoglucanase and â-glucosidase) in balanced quantities. Cellulase activity was determined on solid medium supplemented with 1% carboxy methyl cellulose (CMC). Production of cellulase was detected by the formation of clear or transparent zone around colonies. The greater size of transparent zone has been found proportional to the higher capabilities of the strains for enzymes. The extraction of cellulase enzyme was done in liquid basal medium. The assay of cellulase was observed by measuring the release of reducing sugar (RS) by DNS method. All the three components of cellulase viz. endoglucanase, exoglucanase and â -glucosidase were assayed in terms of CMCase, FPase and cellobiase, respectively and expressed in International units (IU). These strains were further tested for their ability to produce cellulase complex enzyme by growing on a defined substrates as well as on delignified cellulosics. The optimization for â-glucosidase enzyme was carried out by studying the various parameters viz. effect of pH, incubation period and nitrogen sources.Key words: Cellulase, actinomycete, optimization, reducing sugar, carboxy methyl cellulose

Cone beam computed tomography: An accurate imaging technique in comparison with orthogonal portal imaging in intensity-modulated radiotherapy for prostate cancer

Purpose: Various factors cause geometric uncertainties during prostate radiotherapy, including interfractional and intrafractional patient motions, organ motion, and daily setup errors. This may lead to increased normal tissue complications when a high dose to the prostate is administered. More-accurate treatment delivery is possible with daily imaging and localization of the prostate. This study aims to measure the shift of the prostate by using kilovoltage (kV) cone beam computed tomography (CBCT) after position verification by kV orthogonal portal imaging (OPI).Methods: Position verification in 10 patients with prostate cancer was performed by using OPI followed by CBCT before treatment delivery in 25 sessions per patient. In each session, OPI was performed by using an on-board imaging (OBI) system and pelvic bone-to-pelvic bone matching was performed. After applying the noted shift by using OPI, CBCT was performed by using the OBI system and prostate-to-prostate matching was performed. The isocenter shifts along all three translational directions in both techniques were combined into a three-dimensional (3-D) iso-displacement vector (IDV).Results: The mean (SD) IDV (in centimeters) calculated during the 250 imaging sessions was 0.931 (0.598, median 0.825) for OPI and 0.515 (336, median 0.43) for CBCT, p-value was less than 0.0001 which shows extremely statistical significant difference.Conclusion: Even after bone-to-bone matching by using OPI, a significant shift in prostate was observed on CBCT. This study concludes that imaging with CBCT provides a more accurate prostate localization than the OPI technique. Hence, CBCT should be chosen as the preferred imaging technique

Cone beam computed tomography: An accurate imaging technique in comparison with orthogonal portal imaging in intensity-modulated radiotherapy for prostate cancer

Purpose: Various factors cause geometric uncertainties during prostate radiotherapy, including interfractional and intrafractional patient motions, organ motion, and daily setup errors. This may lead to increased normal tissue complications when a high dose to the prostate is administered. More-accurate treatment delivery is possible with daily imaging and localization of the prostate. This study aims to measure the shift of the prostate by using kilovoltage (kV) cone beam computed tomography (CBCT) after position verification by kV orthogonal portal imaging (OPI).Methods: Position verification in 10 patients with prostate cancer was performed by using OPI followed by CBCT before treatment delivery in 25 sessions per patient. In each session, OPI was performed by using an on-board imaging (OBI) system and pelvic bone-to-pelvic bone matching was performed. After applying the noted shift by using OPI, CBCT was performed by using the OBI system and prostate-to-prostate matching was performed. The isocenter shifts along all three translational directions in both techniques were combined into a three-dimensional (3-D) iso-displacement vector (IDV).Results: The mean (SD) IDV (in centimeters) calculated during the 250 imaging sessions was 0.931 (0.598, median 0.825) for OPI and 0.515 (336, median 0.43) for CBCT, p-value was less than 0.0001 which shows extremely statistical significant difference.Conclusion: Even after bone-to-bone matching by using OPI, a significant shift in prostate was observed on CBCT. This study concludes that imaging with CBCT provides a more accurate prostate localization than the OPI technique. Hence, CBCT should be chosen as the preferred imaging technique.</p

In-Depth Molecular Characterization of Mycobacterium tuberculosis from New Delhi – Predominance of Drug Resistant Isolates of the ‘Modern’ (TbD1−) Type

BACKGROUND: India has the highest estimated burden of tuberculosis in the world, accounting for 21% of all tuberculosis cases world-wide. However, due to lack of systematic analysis using multiple markers the available information on the genomic diversity of Mycobacterium tuberculosis in India is limited. METHODOLOGY/PRINCIPAL FINDINGS: Thus, 65 M. tuberculosis isolates from New Delhi, India were analyzed by spoligotyping, MIRU-VNTR, large deletion PCR typing and single nucleotide polymorphism analysis (SNP). The Central Asian (CAS) 1 _DELHI sub-lineage was the most prevalent sub-lineage comprising 46.2% (n = 30) of all isolates, with shared-type (ST) 26 being the most dominant genotype comprising 24.6% (n = 16) of all isolates. Other sub-lineages observed were: East-African Indian (EAI)-5 (9.2%, n = 6), EAI6_BGD1 (6.2%, n = 4), EAI3_IND, CAS and T1 with 6.2% each (n = 4 each), Beijing (4.6%, n = 3), CAS2 (3.1%, n = 2), and X1 and X2 with 1 isolate each. Genotyping results from five isolates (7.7%) did not match any existing spoligopatterns, and one isolate, ST124, belonged to an undefined lineage. Twenty-six percent of the isolates belonged to the TbD1+ PGG1 genogroup. SNP analysis of the pncA gene revealed a CAS-lineage specific silent mutation, S65S, which was observed for all CAS-lineage isolates (except two ST26 isolates) and in 1 orphan. Mutations in the pncA gene, conferring resistance to pyrazinamide, were observed in 15.4% of all isolates. Collectively, mutations in the rpoB gene, the katG gene and in both rpoB and katG genes, conferring resistance to rifampicin and isoniazid, respectively, were more frequent in CAS1_DELHI isolates compared to non-CAS_DELHI isolates (OR: 3.1, CI95% [1.11, 8.70], P = 0.045). The increased frequency of drug-resistance could not be linked to the patients' history of previous anti-tuberculosis treatment (OR: 1.156, CI95% [0.40, 3.36], P = 0.79). Fifty-six percent of all new tuberculosis patients had mutations in either the katG gene or the rpoB gene, or in both katG and rpoB genes. CONCLUSION: CAS1_DELHI isolates circulating in New Delhi, India have a high frequency of mutations in the rpoB and katG genes. A silent mutation (S65S) in the pncA gene can be used as a putative genetic marker for CAS-lineage isolates