Blenkhorn and Sawle Fonds, 1946-1961, n.d. (non-inclusive)

Correspondence, flyers and clippings regarding the Blenkhorn and Sawle Company.

Electrospinning and characterization of self-assembled inclusion complexies

L’électrofilage est une technique permettant de fabriquer des fibres polymériques dont le diamètre varie entre quelques nanomètres et quelques microns. Ces fibres ont donc un rapport surface/volume très élevé. Les fibres électrofilées pourraient trouver des applications dans le relargage de médicaments et le génie tissulaire, comme membranes et capteurs chimiques, ou dans les nanocomposites et dispositifs électroniques. L’électrofilage était initialement utilisé pour préparer des toiles de fibres désordonnées, mais il est maintenant possible d’aligner les fibres par l’usage de collecteurs spéciaux. Cependant, il est important de contrôler non seulement l’alignement macroscopique des fibres mais aussi leur orientation au niveau moléculaire puisque l’orientation influence les propriétés mécaniques, optiques et électriques des polymères. Les complexes moléculaires apparaissent comme une cible de choix pour produire des nanofibres fortement orientées. Dans les complexes d’inclusion d’urée, les chaînes polymères sont empilées dans des canaux unidimensionnels construits à partir d’un réseau tridimensionnel de molécules d’urée liées par des ponts hydrogène. Ainsi, les chaînes polymère sonts très allongées à l’échelle moléculaire. Des nanofibres du complexe PEO-urée ont été préparées pour la première fois par électrofilage de suspensions et de solutions. Tel qu’attendu, une orientation moléculaire inhabituellement élevée a été observée dans ces fibres. De tels complexes orientés pourraient être utilisés à la fois dans des études fondamentales et dans la préparation de matériaux hiérarchiquement structurés. La méthode d’électrofilage peut parfois aussi être utilisée pour préparer des matériaux polymériques métastables qui ne peuvent pas être préparés par des méthodes conventionnelles. Ici, l’électrofilage a été utilisé pour préparer des fibres des complexes stables (α) et "métastables" (β) entre le PEO et l’urée. La caractérisation du complexe β, qui était mal connu, révèle un rapport PEO:urée de 12:8 appartenant au système orthorhombique avec a = 1.907 nm, b = 0.862 nm et c = 0.773 nm. Les chaînes de PEO sont orientées selon l’axe de la fibre. Leur conformation est significativement affectée par les ponts hydrogène. Une structure en couches a été suggérée pour la forme β, plutôt que la structure conventionnelle en canaux adoptée par la forme α. Nos résultats indiquent que le complexe β est thermodynamiquement stable avant sa fonte et peut se transformer en forme α et en PEO liquide par un processus de fonte et recristallisation à 89 ºC. Ceci va dans le sens contraire aux observations faites avec le complexe β obtenu par trempe du complexe α fondu. En effet, le complexe β ainsi obtenu est métastable et contient des cristaux d’urée. Il peut subir une transition de phases cinétique solide-solide pour produire du complexe α dans une vaste gamme de températures. Cette transition est induite par un changement de conformation du PEO et par la formation de ponts hydrogène intermoléculaires entre l’urée et le PEO. Le diagramme de phases du système PEO-urée a été tracé sur toute la gamme de compositions, ce qui a permis d’interpréter la formation de plusieurs mélanges qui ne sont pas à l’équilibre mais qui sont été observés expérimentalement. La structure et le diagramme de phases du complexe PEO-thiourée, qui est aussi un complexe très mal connu, ont été étudiés en détail. Un rapport molaire PEO :thiourée de 3:2 a été déduit pour le complexe, et une cellule monoclinique avec a = 0.915 nm, b = 1.888 nm, c = 0.825 nm et β = 92.35º a été déterminée. Comme pour le complexe PEO-urée de forme β, une structure en couches a été suggérée pour le complexe PEO-thiourée, dans laquelle les molécules de thiourée seraient disposées en rubans intercalés entre deux couches de PEO. Cette structure en couches pourrait expliquer la température de fusion beaucoup plus faible des complexes PEO-thiourée (110 ºC) et PEO-urée de forme β (89 ºC) en comparaison aux structures en canaux du complexe PEO-urée de forme α (143 ºC).

Synthesis and characterization of main-chain bile acid-based degradable polymers

Les acides biliaires sont des composés naturels existants dans le corps humain. Leur biocompatibilité, leur caractère amphiphile et la rigidité de leur noyau stéroïdien, ainsi que l’excellent contrôle de leurs modifications chimiques, en font de remarquables candidats pour la préparation de matériaux biodégradables pour le relargage de médicaments et l'ingénierie tissulaire. Nous avons préparé une variété de polymères à base d’acides biliaires ayant de hautes masses molaires. Des monomères macrocycliques ont été synthétisés à partir de diènes composés de chaînes alkyles flexibles attachées à un noyau d'acide biliaire via des liens esters ou amides. Ces synthèses ont été réalisées par la fermeture de cycle par métathèse, utilisant le catalyseur de Grubbs de première génération. Les macrocycles obtenus ont ensuite été polymérisés par ouverture de cycle, entropiquement induite le catalyseur de Grubbs de seconde génération. Des copolymères ont également été préparés à partir de monolactones d'acide ricinoléique et de monomères cycliques de triester d’acide cholique via la même méthode. Les propriétés thermiques et mécaniques et la dégradabilité de ces polymères ont été étudiées. Elles peuvent être modulées en modifiant les différents groupes fonctionnels décorant l’acide biliaire et en ayant recours à la copolymérisation. La variation des caractéristiques physiques de ces polymères biocompatibles permet de moduler d’autres propriétés utiles, tel que l’effet de mémoire de forme qui est important pour des applications biomédicales.

Coral Reef Ecosystem of Lakshadweep Archipelago –A Biogeochemical Facsimile

The present study focuses on the biochemical aspects of six islands belonging to Lakshadweep Archipelago – namely Kavaratti, Kadamath, Kiltan, Androth, Agathy and Minicoy. Lakshadweep, which is an area biologically significant due to isolation from the major coastline, remains as one of the least studied areas in Indian Ocean. The work, processed out the distributional pattern of trace metals among the biotic (corols, sea weeds and sea grass) and abiotic component (sediments) of ecosystem. An effort is made to picturise the spatial distribution pattern of different forms of nitrogen and phosphorus in the various sedimentary environments of the study area. Studies on the biogeochemical and nutrient aspects of the concerned study area scanty. In Lakshadweep, the local life is very dependent on reefs and its resources. The important stress which produce a threatening effort on the existence for coral reefs are anthropogenic-namely-organic and inorganic pollution from sewage, agricultural and industrial waters, sediment damage from excessive land cleaning, and over exploitation particularly through destructive fishing methods. In addition these one other more localized or less service anthropogenic stress: pollution by oil and other hydrocarbons, complex organic molecular and heavy metal pollution, and destructive engineering practices.

Influvence of Alloying Additions on the Structure and Properties of Ai-7Si-0.3Mg Alloy

Cast Ai-Si alloys are widely used in the automotive, aerospace and general engineering industries due to their excellent combination of properties such as good castability, low coefficient of thermal expansion, high strength-to-weight ratio and good corrosion resistance. The present investigation is on the influence of alloying additions on the structure and properties of Ai-7Si-0.3Mg alloy. The primary objective of this present investigation is to study these beneficial effects of calcium on the structure and properties of Ai-7Si-0.3Mg-xFe alloys. The second objective of this work is to study the effects of Mn,Be and Sr addition as Fe neutralizers and also to study the interaction of Mn,Be,Sr and Ca in Ai-7Si-0.3Mg-xFe alloys. In this study the duel beneficial effects of Ca viz;modification and Fe-neutralization, comparison of the effects of Ca and Sr with common Fe neutralizers. The casting have been characterized with respect to their microstructure, %porosity and electrical conductivity, solidification behaviour and mechanical properties. One of the interesting observations in the present work is that a low level of calcium reduces the porosity compared to the untreated alloy. However higher level of calcium addition lead to higher porosity in the casting. An empirical analysis carried out for comparing the results of the present work with those of the other researchers on the effect of increasing iron content on UTS and % elongation of Ai-Si-Mg and Ai-Si-Cu alloys has shown a linear and an inverse first order polynomial relationships respectively.

An investigation into observational characteristics of rainfall and temperature in Central Northeast India—a historical perspective 1889–2008

Mann–Kendall non-parametric test was employed for observational trend detection of monthly, seasonal and annual precipitation of five meteorological subdivisions of Central Northeast India (CNE India) for different 30-year normal periods (NP) viz. 1889–1918 (NP1), 1919–1948 (NP2), 1949–1978 (NP3) and 1979–2008 (NP4). The trends of maximum and minimum temperatures were also investigated. The slopes of the trend lines were determined using the method of least square linear fitting. An application of Morelet wavelet analysis was done with monthly rainfall during June– September, total rainfall during monsoon season and annual rainfall to know the periodicity and to test the significance of periodicity using the power spectrum method. The inferences figure out from the analyses will be helpful to the policy managers, planners and agricultural scientists to work out irrigation and water management options under various possible climatic eventualities for the region. The long-term (1889–2008) mean annual rainfall of CNE India is 1,195.1 mm with a standard deviation of 134.1 mm and coefficient of variation of 11%. There is a significant decreasing trend of 4.6 mm/year for Jharkhand and 3.2 mm/day for CNE India. Since rice crop is the important kharif crop (May– October) in this region, the decreasing trend of rainfall during themonth of July may delay/affect the transplanting/vegetative phase of the crop, and assured irrigation is very much needed to tackle the drought situation. During themonth of December, all the meteorological subdivisions except Jharkhand show a significant decreasing trend of rainfall during recent normal period NP4. The decrease of rainfall during December may hamper sowing of wheat, which is the important rabi crop (November–March) in most parts of this region. Maximum temperature shows significant rising trend of 0.008°C/year (at 0.01 level) during monsoon season and 0.014°C/year (at 0.01 level) during post-monsoon season during the period 1914– 2003. The annual maximum temperature also shows significant increasing trend of 0.008°C/year (at 0.01 level) during the same period. Minimum temperature shows significant rising trend of 0.012°C/year (at 0.01 level) during postmonsoon season and significant falling trend of 0.002°C/year (at 0.05 level) during monsoon season. A significant 4– 8 years peak periodicity band has been noticed during September over Western UP, and 30–34 years periodicity has been observed during July over Bihar subdivision. However, as far as CNE India is concerned, no significant periodicity has been noticed in any of the time series.

Use of Novel Algorithms MAJE4 and MACJER-320 for Achieving Confidentiality and Message Authentication in SSL & TLS

Extensive use of the Internet coupled with the marvelous growth in e-commerce and m-commerce has created a huge demand for information security. The Secure Socket Layer (SSL) protocol is the most widely used security protocol in the Internet which meets this demand. It provides protection against eaves droppings, tampering and forgery. The cryptographic algorithms RC4 and HMAC have been in use for achieving security services like confidentiality and authentication in the SSL. But recent attacks against RC4 and HMAC have raised questions in the confidence on these algorithms. Hence two novel cryptographic algorithms MAJE4 and MACJER-320 have been proposed as substitutes for them. The focus of this work is to demonstrate the performance of these new algorithms and suggest them as dependable alternatives to satisfy the need of security services in SSL. The performance evaluation has been done by using practical implementation method.

Consequence modelling,vulnerability assessment and fuzzy fault tree analysis of hazardous storages in an industrial area

The hazards associated with major accident hazard (MAH) industries are fire, explosion and toxic gas releases. Of these, toxic gas release is the worst as it has the potential to cause extensive fatalities. Qualitative and quantitative hazard analyses are essential for the identitication and quantification of the hazards associated with chemical industries. This research work presents the results of a consequence analysis carried out to assess the damage potential of the hazardous material storages in an industrial area of central Kerala, India. A survey carried out in the major accident hazard (MAH) units in the industrial belt revealed that the major hazardous chemicals stored by the various industrial units are ammonia, chlorine, benzene, naphtha, cyclohexane, cyclohexanone and LPG. The damage potential of the above chemicals is assessed using consequence modelling. Modelling of pool fires for naphtha, cyclohexane, cyclohexanone, benzene and ammonia are carried out using TNO model. Vapor cloud explosion (VCE) modelling of LPG, cyclohexane and benzene are carried out using TNT equivalent model. Boiling liquid expanding vapor explosion (BLEVE) modelling of LPG is also carried out. Dispersion modelling of toxic chemicals like chlorine, ammonia and benzene is carried out using the ALOHA air quality model. Threat zones for different hazardous storages are estimated based on the consequence modelling. The distance covered by the threat zone was found to be maximum for chlorine release from a chlor-alkali industry located in the area. The results of consequence modelling are useful for the estimation of individual risk and societal risk in the above industrial area.Vulnerability assessment is carried out using probit functions for toxic, thermal and pressure loads. Individual and societal risks are also estimated at different locations. Mapping of threat zones due to different incident outcome cases from different MAH industries is done with the help of Are GIS.Fault Tree Analysis (FTA) is an established technique for hazard evaluation. This technique has the advantage of being both qualitative and quantitative, if the probabilities and frequencies of the basic events are known. However it is often difficult to estimate precisely the failure probability of the components due to insufficient data or vague characteristics of the basic event. It has been reported that availability of the failure probability data pertaining to local conditions is surprisingly limited in India. This thesis outlines the generation of failure probability values of the basic events that lead to the release of chlorine from the storage and filling facility of a major chlor-alkali industry located in the area using expert elicitation and proven fuzzy logic. Sensitivity analysis has been done to evaluate the percentage contribution of each basic event that could lead to chlorine release. Two dimensional fuzzy fault tree analysis (TDFFTA) has been proposed for balancing the hesitation factor invo1ved in expert elicitation .

Studies on the isolation and characterization of flavones and triterpenoids from a few plants

In the present scenario, there is an increasing demand for natural products in food industry, pharmaceuticals, cosmetics and agricultural sectors. In this context phytochemical study to identify newer chemicals has got great relevance. Phytochemical studies have become more reliable and encouraging with the development of modern analytical techniques.In the present work the leaves of Piper colubrinum (Piperaceae), aerial parts of Mussaenda fiondosa (Rubiaceae) and Humboldtia vahliana (Leguminosae) and the pericarp of fruits of Artocarpus heterophyllus (Moraceae) were investigated for their secondary metabolites. The major compounds isolated belong to the groups of flavonoids and triterpenoids.Naturally occurring flavonoids have been used widely in chemotaxonomic studies of plants. Flavones and flavonols constitute a group of biosynthetically related natural products. No universal function has been established for flavones and flavonols in plants. However, many functions in individual plants have been demonstrated. These include protection of plants from ultraviolet light, insects and pests; pollinator attractants; antioxidants; plant hormone controllers; enzyme inhibitors and allelopathic agents. Flavonoids are attracting the attention of medical scientists in recent years because of their anticarcinogenic, antiallergic and antiinflammatory properties. The recent discovery that flavonoids are involved in the process of nitrogen fixation in plants also opens the way for agricultural application of these constituents.Triterpenoids are another class of compounds that are ubiquitous in plants. Some triterpenoids present in the latex and resins of plants are believed to be involved in chemical defence against pathogens and herbivores. Triterpenoids possess various biological properties including anti-inflammatory, antifeedant, pesticidal, fungitoxic and antimicrobial activities. Triterpenoids with cytotoxic activity and inhibitory effect on seed germination are also known.

Qualitative Air Flow Modelling and Analysis of Data Centre Air Conditioning as Multiple Jet Array

Data centre is a centralized repository,either physical or virtual,for the storage,management and dissemination of data and information organized around a particular body and nerve centre of the present IT revolution.Data centre are expected to serve uniinterruptedly round the year enabling them to perform their functions,it consumes enormous energy in the present scenario.Tremendous growth in the demand from IT Industry made it customary to develop newer technologies for the better operation of data centre.Energy conservation activities in data centre mainly concentrate on the air conditioning system since it is the major mechanical sub-system which consumes considerable share of the total power consumption of the data centre.The data centre energy matrix is best represented by power utilization efficiency(PUE),which is defined as the ratio of the total facility power to the IT equipment power.Its value will be greater than one and a large value of PUE indicates that the sub-systems draw more power from the facility and the performance of the data will be poor from the stand point of energy conservation. PUE values of 1.4 to 1.6 are acievable by proper design and management techniques.Optimizing the air conditioning systems brings enormous opportunity in bringing down the PUE value.The air conditioning system can be optimized by two approaches namely,thermal management and air flow management.thermal management systems are now introduced by some companies but they are highly sophisticated and costly and do not catch much attention in the thumb rules.

Behaviour of laterised normal and self compacting concrete subjected to elevated temperatures

Concrete is a universal material in the construction industry. With natural resources like sand and aggregate, fast depleting, it is time to look for alternate materials to substitute these in the process of making concrete. There are instances like exposure to solar radiation, fire, furnaces, and nuclear reactor vessels, special applications like missile launching pads etc., where concrete is exposed to temperature variations In this research work, an attempt has been made to understand the behaviour of concrete when weathered laterite aggregate is used in both conventional and self compacting normal strength concrete. The study has been extended to understand the thermal behaviour of both types of laterised concretes and to check suitability as a fire protection material. A systematic study of laterised concrete considering parameters like source of laterite aggregate, grades of Ordinary Portland Cement (OPC) and types of supplementary cementitious materials (fly ash and GGBFS) has been carried out to arrive at a feasible combination of various ingredients in laterised concrete. A mix design methodology has been proposed for making normal strength laterised self compacting concrete based on trial mixes and the same has also been validated. The physical and mechanical properties of laterised concretes have been studied with respect to different variables like exposure temperature (200°C, 400°C and 600°C) and cooling environment (air cooled and water cooled). The behaviour of ferrocement elements with laterised self compacting concrete has also been studied by varying the cover to mesh reinforcement (10mm to 50mm at an interval of 10mm), exposure temperature and cooling environment.

Qualitative air flow modelling and analysis of data centre air conditioning as multiple jet array

This work identifies the importance of plenum pressure on the performance of the data centre. The present methodology followed in the industry considers the pressure drop across the tile as a dependant variable, but it is shown in this work that this is the only one independent variable that is responsible for the entire flow dynamics in the data centre, and any design or assessment procedure must consider the pressure difference across the tile as the primary independent variable. This concept is further explained by the studies on the effect of dampers on the flow characteristics. The dampers have found to introduce an additional pressure drop there by reducing the effective pressure drop across the tile. The effect of damper is to change the flow both in quantitative and qualitative aspects. But the effect of damper on the flow in the quantitative aspect is only considered while using the damper as an aid for capacity control. Results from the present study suggest that the use of dampers must be avoided in data centre and well designed tiles which give required flow rates must be used in the appropriate locations. In the present study the effect of hot air recirculation is studied with suitable assumptions. It identifies that, the pressure drop across the tile is a dominant parameter which governs the recirculation. The rack suction pressure of the hardware along with the pressure drop across the tile determines the point of recirculation in the cold aisle. The positioning of hardware in the racks play an important role in controlling the recirculation point. The present study is thus helpful in the design of data centre air flow, based on the theory of jets. The air flow can be modelled both quantitatively and qualitatively based on the results.

“Qualitative Air Flow Modelling And Analysis Of Data Centre Air Conditioning As Multiple Jet Array

In the present study the effect of hot air recirculation is studied with suitable assumptions. It identifies that, the pressure drop across the tile is a dominant parameter which governs the recirculation. The rack suction pressure of the hardware along with the pressure drop across the tile determines the point of recirculation in the cold aisle. The positioning of hardware in the racks play an important role in controlling the recirculation point. The present study is thus helpful in the design of data centre air flow, based on the theory of jets. The air flow can be modelled both quantitatively and qualitatively based on the results

Assessment of Energy Conservation in Indian Cement Industry and Forecasting of Co2 Emissions

Cement industry ranks 2nd in energy consumption among the industries in India. It is one of the major emitter of CO2, due to combustion of fossil fuel and calcination process. As the huge amount of CO2 emissions cause severe environment problems, the efficient and effective utilization of energy is a major concern in Indian cement industry. The main objective of the research work is to assess the energy cosumption and energy conservation of the Indian cement industry and to predict future trends in cement production and reduction of CO2 emissions. In order to achieve this objective, a detailed energy and exergy analysis of a typical cement plant in Kerala was carried out. The data on fuel usage, electricity consumption, amount of clinker and cement production were also collected from a few selected cement industries in India for the period 2001 - 2010 and the CO2 emissions were estimated. A complete decomposition method was used for the analysis of change in CO2 emissions during the period 2001 - 2010 by categorising the cement industries according to the specific thermal energy consumption. A basic forecasting model for the cement production trend was developed by using the system dynamic approach and the model was validated with the data collected from the selected cement industries. The cement production and CO2 emissions from the industries were also predicted with the base year as 2010. The sensitivity analysis of the forecasting model was conducted and found satisfactory. The model was then modified for the total cement production in India to predict the cement production and CO2 emissions for the next 21 years under three different scenarios. The parmeters that influence CO2 emissions like population and GDP growth rate, demand of cement and its production, clinker consumption and energy utilization are incorporated in these scenarios. The existing growth rate of the population and cement production in the year 2010 were used in the baseline scenario. In the scenario-1 (S1) the growth rate of population was assumed to be gradually decreasing and finally reach zero by the year 2030, while in scenario-2 (S2) a faster decline in the growth rate was assumed such that zero growth rate is achieved in the year 2020. The mitigation strategiesfor the reduction of CO2 emissions from the cement production were identified and analyzed in the energy management scenarioThe energy and exergy analysis of the raw mill of the cement plant revealed that the exergy utilization was worse than energy utilization. The energy analysis of the kiln system showed that around 38% of heat energy is wasted through exhaust gases of the preheater and cooler of the kiln sysetm. This could be recovered by the waste heat recovery system. A secondary insulation shell was also recommended for the kiln in the plant in order to prevent heat loss and enhance the efficiency of the plant. The decomposition analysis of the change in CO2 emissions during 2001- 2010 showed that the activity effect was the main factor for CO2 emissions for the cement industries since it is directly dependent on economic growth of the country. The forecasting model showed that 15.22% and 29.44% of CO2 emissions reduction can be achieved by the year 2030 in scenario- (S1) and scenario-2 (S2) respectively. In analysing the energy management scenario, it was assumed that 25% of electrical energy supply to the cement plants is replaced by renewable energy. The analysis revealed that the recovery of waste heat and the use of renewable energy could lead to decline in CO2 emissions 7.1% for baseline scenario, 10.9 % in scenario-1 (S1) and 11.16% in scenario-2 (S2) in 2030. The combined scenario considering population stabilization by the year 2020, 25% of contribution from renewable energy sources of the cement industry and 38% thermal energy from the waste heat streams shows that CO2 emissions from Indian cement industry could be reduced by nearly 37% in the year 2030. This would reduce a substantial level of greenhouse gas load to the environment. The cement industry will remain one of the critical sectors for India to meet its CO2 emissions reduction target. India’s cement production will continue to grow in the near future due to its GDP growth. The control of population, improvement in plant efficiency and use of renewable energy are the important options for the mitigation of CO2 emissions from Indian cement industries

Characterization of Bacteriocins from Bacillus licheniformis strain BTHT8 and Bacillus subtilis strain BTFK101 isolated from marine sediment

Pathogenic microorganisms such as Bacillus cereus, Listeria Monocytogenes and Staphylococcus sp have caused serious diseases, and consequently contributed to considerable economic loss in the food and agricultural industries. Antibiotics have been practically used to treat these pathogens since penicillin G was discovered more than half a century ago. Many different types of antibiotics have been discovered or synthesized to control pathogenic microorganisms. Repetitive use and misuse of antibiotics by the agricultural and pharmaceutical industries have caused the emergence of multidrug-resistant microorganisms, even to the strongest antibiotics currently available; therefore, the rapid development of more effective antimicrobial compounds is required to keep pace with demand. Bacteria were isolated from marine water and sediment samples collected from various locations off the coast of Cochin and salt pans of Tuticorin using pour plate technique. One hundred and twelve isolates were obtained. Seventeen isolates exhibiting antimicrobial activity were segregated after primary screening. The secondary screening which was aimed at selection of bacteria that produce proteinaceous inhibitory compounds, helped to select five strains viz. BTFK101, BTHT8, BTKM4, BTEK16 and BTSB22. The five isolates inhibited the growth of six Gram positive test organisms viz. B. cereus, B. circulans, B. coagulans, B. pumilus, Staphylococcus aureus and Clostridium perfringens. After quantitative estimation of the bacteriocin production, the two strains BTFK101 and BTHT8 were selected for further study.