A hybrid biogas system for Kolkata

Municipal solid waste (MSW) is a global problem. Four processes for treatment include landfilling, incineration, recycling and composting the organic fraction. Landfilling can cause the release of the potent greenhouse gas methane into the atmosphere. In many parts of the world, including the European Union, legislation to limit the amount of generated Organic Fraction Municipal Solid Wastes (OFMSW) going to landfill has been introduced. An alternative to landfilling is to anaerobically digest the OFMSW. This paper investigates the concept of a Hybrid Biomass System (HBS) consisting of solar thermal Flat Plat Collector (FPC) providing heat energy to the thermophilic (55oC) anaerobic digestion process, and the potential energy yield of hotel OFMSW in Kolkata. The methodology comprises development and assessment of a theoretical model representing the anaerobic digestion process for optimum biogas yield and TRNSYS simulation of a 5m2 and 10m2 FPC. Theoretical biogas production rates derived are 0.44m3/kgVS or 0.21m3 biogas/guest/day with a C/N ratio of 35:1. 5m2 and 10m2 FPC simulations maintained the thermophilic temperature of 55oC within -1.9 and +2.1. 10m2 FPC provides largest energy contribution at 11% of the annual energy requirement. In is concluded that FPCs can support thermophilic digester heating requirements with heat store or direct integration. In order to meet optimum biogas yield, legislation and policy is required to evolve the current waste management processes with emphasis on infrastructure development and source segregation

Activated carbon from Moringa husks and pods

Moringa oleifera is the most widespread species of the plant family Moringaceae. It is a rapidly growing tree native to the sub-Himalayan regions of north-west India and indigenous to many parts of Africa, South America and Asia, typically reaching a height of 3-4 metres, flowering and fruiting in one year from a 0.3 metre seedling even in poor quality soil (Sutherland, Folkard et al., 1994). It is known by different names around the world (Jahn, 1986), for example in India “Drumstick” or “Horseradish” tree. The tree produces large seed pods which can either be harvested when green for food or left to dry. The dried seeds can be crushed to produce a high quality vegetable oil and the resulting press-cake mixed with water and strained to form a coagulant for water treatment (McConnachie, Mtawali et al., 1994). The residue containing seed husks is currently discarded as waste. The research presented here has been carried out at the University of Edinburgh and the University of Malawi and demonstrates that a simple steam pyrolysis procedure can form high quality microporous activated carbons from both the waste husks of Moringa oleifera and the pods. The work is part of an overall assessment of the viability of the establishment of Moringa oleifera plantations in tropical areas for the benefit of rural communities and is being carried out in collaboration with the Engineering Department, The University of Leicester, U.K

The production and composition of Chinese lead-barium glass through experimental laboratory replication

Lead-barium glass appeared during the late Warring States period in China (457 -221 BCE) and was considered as a Chinese invention due to the unique presence of high barium. There is no indication as to how it was made. A set of twenty-four different combinations of possible raw materials were melted to test and systematically evaluate the possible recipes for lead-barium glass. Specifically, the function and source of sodium in lead -barium glass were explored. The results show that sodium source is crucial for lead-barium glass forming in this particular system. This paper explores an alternative formulation since sodium flux is not reported in historical Chinese sources, in which the Na2O is provided by including soda-lime glass in the mixture. This particular formulation provides a potential explanation for the source of the sodium in lead-barium glass.Material Culture Studie

Hard Instances of the Constrained Discrete Logarithm Problem

The discrete logarithm problem (DLP) generalizes to the constrained DLP, where the secret exponent $x$ belongs to a set known to the attacker. The complexity of generic algorithms for solving the constrained DLP depends on the choice of the set. Motivated by cryptographic applications, we study sets with succinct representation for which the constrained DLP is hard. We draw on earlier results due to Erd\"os et al. and Schnorr, develop geometric tools such as generalized Menelaus' theorem for proving lower bounds on the complexity of the constrained DLP, and construct sets with succinct representation with provable non-trivial lower bounds

Ice sheet model dependency of the simulated Greenland Ice Sheet in the mid-Pliocene

The understanding of the nature and behavior of ice sheets in past warm periods is important for constraining the potential impacts of future climate change. The Pliocene warm period (between 3.264 and 3.025 Ma) saw global temperatures similar to those projected for future climates; nevertheless, Pliocene ice locations and extents are still poorly constrained. We present results from the efforts to simulate mid-Pliocene Greenland Ice Sheets by means of the international Pliocene Ice Sheet Modeling Intercomparison Project (PLISMIP). We compare the performance of existing numerical ice sheet models in simulating modern control and mid-Pliocene ice sheets with a suite of sensitivity experiments guided by available proxy records. We quantify equilibrated ice sheet volume on Greenland, identifying a potential range in sea level contributions from warm Pliocene scenarios. A series of statistical measures are performed to quantify the confidence of simulations with focus on inter-model and inter-scenario differences. We find that Pliocene Greenland Ice Sheets are less sensitive to differences in ice sheet model configurations and internal physical quantities than to changes in imposed climate forcing. We conclude that Pliocene ice was most likely to be limited to the highest elevations in eastern and southern Greenland as simulated with the highest confidence and by synthesizing available regional proxies; however, the extent of those ice caps needs to be further constrained by using a range of general circulation model (GCM) climate forcings

An Anglo-Saxon execution cemetery at Walkington Wold, Yorkshire

This paper presents a re-evaluation of a cemetery excavated over 30 years ago at Walkington Wold in east Yorkshire. The cemetery is characterized by careless burial on diverse alignments, and by the fact that most of the skeletons did not have associated crania. The cemetery has been variously described as being the result of an early post-Roman massacre, as providing evidence for a ‘Celtic’ head cult or as an Anglo-Saxon execution cemetery. In order to resolve the matter, radiocarbon dates were acquired and a re-examination of the skeletal remains was undertaken. It was confirmed that the cemetery was an Anglo-Saxon execution cemetery, the only known example from northern England, and the site is set into its wider context in the paper

Human toxocariasis: contribution by Brazilian researchers

In the present paper the main aspects of the natural history of human infection by Toxocara larvae that occasionally result in the occurrence of visceral and/or ocular larva migrans syndrome were reviewed. The contribution by Brazilian researchers was emphasized, especially the staff of the Tropical Medicine Institute of São Paulo (IMT)

Liposomes in Biology and Medicine

Drug delivery systems (DDS) have become important tools for the specific delivery of a large number of drug molecules. Since their discovery in the 1960s liposomes were recognized as models to study biological membranes and as versatile DDS of both hydrophilic and lipophilic molecules. Liposomes--nanosized unilamellar phospholipid bilayer vesicles--undoubtedly represent the most extensively studied and advanced drug delivery vehicles. After a long period of research and development efforts, liposome-formulated drugs have now entered the clinics to treat cancer and systemic or local fungal infections, mainly because they are biologically inert and biocompatible and practically do not cause unwanted toxic or antigenic reactions. A novel, up-coming and promising therapy approach for the treatment of solid tumors is the depletion of macrophages, particularly tumor associated macrophages with bisphosphonate-containing liposomes. In the advent of the use of genetic material as therapeutic molecules the development of delivery systems to target such novel drug molecules to cells or to target organs becomes increasingly important. Liposomes, in particular lipid-DNA complexes termed lipoplexes, compete successfully with viral gene transfection systems in this field of application. Future DDS will mostly be based on protein, peptide and DNA therapeutics and their next generation analogs and derivatives. Due to their versatility and vast body of known properties liposome-based formulations will continue to occupy a leading role among the large selection of emerging DDS