Service learning in Loyola College, Chennai : Loyola Extension Awareness Programme (LEAP) : for first year PG students

The subjects that the students study in the class room should be deeply reflected in the field. It should not be mere observation learning, but actually plunging into action through demonstration. For example, Students of the Chemistry Department rightly chooses to conduct the consumer awareness programme by demonstrating some adulterated food and its adverse impact on health. Students of commerce departments should study the business know-how, various marketing techniques and new innovation in business. Students of economics department should study the developmental schemes of the government and its impact on the rural Masses. Thus service learning in Loyola is of two types. 1. RURAL IMMERSION • 7 days of Rural camp in villages. Objectives: • To enable students to develop people oriented attitudes and to imbibe the spirit of concern for others. • To initiate team process among the students\u27 groups. • To learn from the people about the realities at the grassroot level and develop a critical consciousness Dynamics of the programme During I year of Undergraduate, Students are provided rural exposure wherein they stay for six days and live the life of the underprivileged masses. • Motivational session and immersion before going to the field • Input on the stark realities of rural areas of India • Orientation on the rural dynamics of India by the resource person to understand the dynamics of the community • The teams exhibit their learning in the form of chart presentation, or through drama, skit and action songs. Summing-up session by the resource person • Students will share about their difficulties and problems of the village they hail from. Since the students are formed into various groups and they will write their Group Reports. Methodology of visit 1. Observation 2. Interaction with the people in villages 3. Focused group discussion 4. In-depth interviews with individuals 5. Exposure \u3e experiment \u3e experience \u3e impact \u3einvolvement. 2. URBAN IMMERSION The students will be placed in the NGOs in the city of Chennai and will be taken to exposure visits to various NGOs. Students are grouped into teams depending on the size. Each team will take-up two programmes, one in the community and the other in the institution. Visits to slums by staff in-charge of Outreach will be arranged

Effect of solvents on the rearrangement of aromatic acetals by iodobenzene- dichloride

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Durability and Microstructure of Cement Composites Containing Qatar's Municipal Wastes

Qatar produces more than 2.5 million tons of municipal waste per year with an average waste generation rate of 1.8 kg/day/capita which is one of the highest rates in the world. The rapid growth of municipal solid waste has become one of the serious environmental problem that Qatar is facing with. Qatar's municipal waste is composed of organic and recyclables materials. Municipal solid waste incineration has been performed in Qatar since 2011. By incineration of wastes, not only the volume and weight of wastes are reduced but also energy is generated. Prior to incineration of municipal wastes, recyclables are separated from the waste and the remaining waste is incinerated at a minimum temperature of 850oC. Bottom ash and fly ash are produced as a result of incineration process. These by-products may contain heavy metals and pose a thread to the environment hence needs treatment and/or special disposal. Approximately 60 tonnes of fly ash is generated daily from municipal waste incineration in Qatar and this ash called as municipal solid waste incineration (MSWI) fly ash. This MSWI fly ash is stabilised with cement and then disposed into special landfill. However, cementitious property of MSWI fly ash due to similar mineralogical composition with cement and its finer particle size may favor its potential utilisation in cement based materials. As aforementioned before, 40% of municipal waste of Qatar is composed of recyclables of which 14% is plastic. The major portion of plastic wastes, about 90% of total, are composed of light density polyethylene (LDPE) and high density polyethylene (HDPE) wastes. Therefore, there is a huge potential for recycling of PE wastes in Qatar considering the shortage of raw materials i.e. natural aggregate for construction industry. The scarcity of available land for disposal of municipal wastes and limited natural resources of raw materials for construction industry has opened new research areas for proper disposal and recycling of municipal wastes. Therefore, in this research work, municipal solid waste incineration (MSWI) fly ash and municipal polymeric wastes were used as secondary raw materials for the preparation of cement based composites. MSWI fly ash was utilised as partial replacement of cement by 10% by weight. Polyetyhlene wastes in granular form were utilised as partial replacement of natural aggregate by 10% by volume. Portland cement, silica fume (10% by weight) and MSWI FA (10% by weight) at constant rates were used as binder in all cement-based composites. Three different cement based composites were fabricated by partial substition of natural aggregate with LDPE and HDPE wastes at 0 and 10% by volume. The mixture without PE waste substitution was called as the reference mixture, with LDPE waste was called as Mix 1 and with HDPE waste was called as Mix 2. Besides mechanical performance, durability of fabricated cement composites containing municipal wastes was investigated to determine if their utilisation has positive contribution or adverse impact. The durability properties were examined by performing drying shrinkage and expansion under sulfate exposure tests. Scanning electron microscopy coupled with EDX were used to determine the degradation products of sulfate exposure. In terms of mechanical strength, samples containing PE wastes showed lower strength at early ages due to weaker bonding between LDPE/HDPE and the cement matrix. At later ages, strength improvement was observed and comparable strength values for Mix 1 and Mix 2 were measured with respect to the reference. The effect of utilisation of municipal wastes on the dimensional stability of cement composites was evaluated by measuring the variation of length change at 4, 11, 18, 25, 126 and 168 days of air drying. This test showed that incorporation of PE wastes (Mix 1 and Mix 2) reduced the drying shrinkage and provided better dimensional stability compared to the reference. Sulfate attack is known as one of the most deleterious effects on cement based composites due to the formation of expansive degradation products. To investigate the sulfate resistance of fabricated composites, the length change at 1 week, 2 weeks, 3 weeks, 4 weeks, 8 weeks, 13 weeks, 15 weeks, 4 months and 6 months of sulfate exposure was measured. Both the reference and samples containing PE wastes did not show any visual deterioration except a white and soft layer formed on top of all samples. The length change indicated that composites containing PE wastes experienced reduction in expansion compared to the reference and hence considered as more durable for external sulfate attack. More voids and pores were present in PE incorporated samples, therefore sulfate degradation products probably filled these pores and resulted in lower expansion compared to the reference. There was no significant difference between the mechanical performance and durability of cement composites containing LDPE and HDPE. The microstructure and composition of sulfate degradation products were investigated by SEM-EDX. The decalcification of the C-S-H phase were detected in each sample. Gypsum, calcite and thaumasite were identified as the major deterioration related products, while ettringite was found at trace level. This laboratory study showed that MSWI fly ash and PE wastes can be utilised together to produce durable cement based materials with a lower carbon footprint.qscienc

Dynamics and Selective Remodeling of the DNA-binding Domains of RPA

Replication protein A (RPA) coordinates important DNA metabolic events by stabilizing single-stranded DNA (ssDNA) intermediates, activating the DNA-damage response and handing off ssDNA to the appropriate downstream players. Six DNA-binding domains (DBDs) in RPA promote high-affinity binding to ssDNA yet also allow RPA displacement by lower affinity proteins. We generated fluorescent versions of Saccharomyces cerevisiae RPA and visualized the conformational dynamics of individual DBDs in the context of the full-length protein. We show that both DBD-A and DBD-D rapidly bind to and dissociate from ssDNA while RPA remains bound to ssDNA. The recombination mediator protein Rad52 selectively modulates the dynamics of DBD-D. These findings reveal how RPA-interacting proteins with lower ssDNA binding affinities can access the occluded ssDNA and remodel individual DBDs to replace RPA

Dilemmas of resistance: How concerns for cultural aspects of identity shape and constrain resistance among minority groups

A major theme in social psychological models of collective action is that shared social identity is a critical foundation for resistance and collective action. In this review, we suggest that this foundational role of social identity can be double edged for many minority groups because material disadvantage is often coupled with the historical erosion of key aspects of ingroup culture and identity. Focusing on the role of ingroup language in Welsh national identity and history in relation to African identity, we present an integrative review of our research on five different dilemmas of resistance that can arise when perceived threats to socio-cultural aspects identity sit alongside threats to the material position (in terms of status and power) of the group. We conclude that the central role of social identity in collective action and resistance can itself present challenges for groups whose core sense of who they are has been eroded.

How does internal angle of hoppers affect granular flow? Experimental studies using Digital Particle Image Velocimetry

Mechanical behaviour of powders and grains often displays features of solid-like and liquid-like characteristics of matter. In spite of processing granular materials quite extensively in the industries, their flow behaviour is still complex to understand under different process conditions. In this paper, using Digital Particle Image Velocimetry (DPIV) and high speed videography, we probe systematically on the spatial and temporal distribution of the velocity fields of pharmaceutical excipient granules flowing though smooth hoppers with different internal (orifice) angles. This helps to visualise and identify the locations and formation of the flow channels and conversely the stagnation zones of granular materials inside the hoppers as a function of the internal angle of the hoppers. We show that even when a powder characterised as a free-flowing type in the conventional sense could experience a significant level of hindrance to flow when passing through smooth hoppers of different internal angles and its impact increases with increase in the internal angle. Theoretical predictions are made using experimentally evaluated grain-scale properties as input parameters for understanding the effects of hopper angle on the granular flow rate. A good level of agreement is obtained between the experimental and theoretical estimates of the granular flow rate in terms of the hopper angle. The outcomes presented here are a step forward in designing granular flow devices more efficiently in the future

Prospecting for Energy-Rich Renewable Raw Materials: \u3cem\u3eAgave\u3c/em\u3e Leaf Case Study

Plant biomass from different species is heterogeneous, and this diversity in composition can be mined to identify materials of value to fuel and chemical industries. Agave produces high yields of energy-rich biomass, and the sugar-rich stem tissue has traditionally been used to make alcoholic beverages. Here, the compositions of Agave americana and Agave tequilana leaves are determined, particularly in the context of bioethanol production. Agave leaf cell wall polysaccharide content was characterized by linkage analysis, non-cellulosic polysaccharides such as pectins were observed by immuno-microscopy, and leaf juice composition was determined by liquid chromatography. Agave leaves are fruit-like--rich in moisture, soluble sugars and pectin. The dry leaf fiber was composed of crystalline cellulose (47-50% w/w) and non-cellulosic polysaccharides (16-22% w/w), and whole leaves were low in lignin (9-13% w/w). Of the dry mass of whole Agave leaves, 85-95% consisted of soluble sugars, cellulose, non-cellulosic polysaccharides, lignin, acetate, protein and minerals. Juice pressed from the Agave leaves accounted for 69% of the fresh weight and was rich in glucose and fructose. Hydrolysis of the fructan oligosaccharides doubled the amount of fermentable fructose in A. tequilana leaf juice samples and the concentration of fermentable hexose sugars was 41-48 g/L. In agricultural production systems such as the tequila making, Agave leaves are discarded as waste. Theoretically, up to 4000 L/ha/yr of bioethanol could be produced from juice extracted from waste Agave leaves. Using standard Saccharomyces cerevisiae strains to ferment Agave juice, we observed ethanol yields that were 66% of the theoretical yields. These data indicate that Agave could rival currently used bioethanol feedstocks, particularly if the fermentation organisms and conditions were adapted to suit Agave leaf composition

Citostatsko i protuupalno djelovanje polisaharida biljke Ganoderma lucidum

In this study, polysaccharides were isolated from Ganoderma lucidum (Polyporaceae) and their antitumor and anti-inflammatory activities were investigated using in vivo models. Potential antitumor activity was shown by G. lucidum polysaccharides (GLP) against solid tumor induced by Ehrlich’s ascites carcinoma cells. GLP at 100 mg kg–1 body mass showed 80.8 and 77.6 % reduction in tumour volume and tumour mass, respectively, when administered 24 h after tumour implantation. Again, GLP at the same dose but when administered prior to tumour inoculation, showed 79.5 and 81.2 % inhibition of tumour volume and tumour mass, respectively. GLP showed significant dose-dependent activity in carrageenean-induced (acute) and formalin-induced (chronic) inflammation assays. At 100 mg kg–1, GLP exhibited 57.6 and 58.2 % inhibition in carrageenean-induced and formalin-induced assays, respectively.U radu je ispitano in vivo citostatsko i protuupalno djelovanje polisaharida (GLP) izoliranih iz biljke Ganoderma lucidum (Polyporaceae). Ispitivani polisaharidi pokazali su potencijalno antitumorsko djelovanje na Ehrlichov ascitesni tumor. GLP su u dozi od 100 mg kg1 tjelesne mase inhibirali volumen tumora za 80,8, a njegovu masu za 77,6 %, kada su primijenjeni 24 h nakon implantacije tumora. Ako se GLP daju u istoj dozi prije inokulacije tumora, inhibiraju volumen tumora za 79,5, a njegovu masu za 81,2 %. GLP pokazuju značajno, o dozi ovisno, protuupalno djelovanje u karagenan testu (akutna upala) i formalin testu (kronična upala). U dozi od 100 mg kg1, GLP inhibiraju upalne procese za 57,6 odnosno 58,2 % u testu s karagenanom, odnosno formalinom