Discrimination of explosions and earthquakes: An example based on spectra and source parameters of the 11<Superscript>th</Superscript> May 1998 Pokhran explosion and the 9<Superscript>th</Superscript> April 2009 earthquake

We compare the P-, S- and Lg- spectra of the 11^th May, 1998 Pokhran underground nuclear explosion (NE) with those of an earthquake (EQ) of comparable magnitude that occurred in its vicinity (~100 km west) on 9^th April, 2009, utilizing the waveforms recorded by a Global Seismograph Network station at Nilore (NIL), Pakistan. The contiguous occurrence of these events and the similarity of the travel paths provided a good opportunity to discriminate the nature of the sources. Our results suggest that the Pn/Lg and Pn/Sn amplitude ratios of the explosion and earthquake waveforms exhibit distinct differences in the higher frequency window. Further, since the P-phases have high signal to noise ratio compared to their S counterparts, we utilize their spectra to derive the source parameters of the NE and EQ sources. Our results show that the seismic moment, corner frequency and source dimension of the explosion are ~1.58X10¹⁷ Nm, 1.18 Hz and ~0.793 km respectively. The moment magnitude (M_W) and surface wave magnitude (M_S) for the nuclear explosion are estimated to be ~5.4 and ~3.57 respectively. The values of M_W (5.3) and M_S (4.3) obtained by us for the earthquake are consistent with the estimates in the Harvard catalog and earlier published results. The estimate of M_W for the nuclear explosion was hitherto not available. Lastly, we estimate the yield of the NE to be ~50 kt from the surface wave magnitude and discuss the various limitations related to its estimation.     

Radiation condensation instability in a plasma with ionization and recombination

In this work, we consider radiation (thermal) instability in a weakly ionized plasma with continuous ionization and recombination. The situation can be visualized in the case of envelopes of planetary nebulae, which are envelopes of ionized plasmas surrounding red giant stars. Various observations report continuous photoionization of these plasmas by the highly energetic streams of photons emanating from the parent star. Recently, it has been shown that thermal instability can be a probable candidate in such plasmas for the existence of small scale structures (viz., striations) whose kinematic age is much smaller than that of the parent nebula. We therefore report a systematic study of these plasmas with photoionization and determine the instability domain. We have shown that the continuous ionization and recombination may lead to modification of the underlying instability, which may limit the size of the small structures that are believed to form from these instabilities, and may thus provide an explanation of the physical processes responsible for the existence of these structures. We further show that in many cases the system bifurcates to an ovserstable (growing wave) state from a condensation instability (monotonic) and vice versa.     

The chemical composition of tertiary Indian coal ash and its combustion behaviour – a statistical approach: Part 2

In Part 1 of the present investigation, 37 representative Eocene coal samples of Meghalaya, India were analyzed and their physico-chemical characteristics and the major oxides and minerals present in ash samples were studied for assessing the genesis of these coals. Various statistical tools were also applied to study their genesis. The datasets from Part 1 used in this investigation (Part 2) show the contribution of major oxides towards ash fusion temperatures (AFTs). The regression analysis of high temperature ash (HTA) composition and initial deformation temperature (IDT) show a definite increasing or decreasing trend, which has been used to determine the predictive indices for slagging, fouling, and abrasion propensities during combustion practices. The increase or decrease of IDT is influenced by the increase of Fe₂O₃, Al₂O₃, SiO₂, and CaO, respectively. Detrital-authigenic index (DAI) calculated from the ash composition and its relation with AFT indicates Sialoferric nature of these coals. The correlation analysis, Principal Component Analysis (PCA), and Hierarchical Cluster Analysis (HCA) were used to study the possible fouling, slagging, and abrasion potentials in boilers during the coal combustion processes. A positive relationship between slagging and heating values of the coal has been found in this study.     

Microflora from sauropod coprolites and associated sediments of Late Cretaceous (Maastrichtian) Lameta Formation of Nand-Dongargaon basin,Maharashtra

Micofloral study of Lameta sediments and associated sauropod coprolites in the Nand-Dongargaon basin in Maharashtra was conducted to understand the diet and habitat of sauropods. The study revealed the presence of pollen, spores, algal and fungal remains, well-preserved cuticles of Poaceae, and testate amoebae. Vegetation during Lameta included tall arboreal taxa, such as conifers (Podocarpus and Araucaria), Cycads (Cycas), Euphorian and Barringtonia and herbs and shrubs, such as Cheirolepidiaceae (Classopollis), Arecaceae (Palmaepollenites), Poaceae (Graminidites), Asteraceae (Compositoipollenites), Caryophyllaceae (Cretacaeiporites and Periporopollenites), and Acanthaceae (Multiareolites). Data suggest that the sauropods ate soft tissues of angiosperms and gymnosperms. The intake of testate amoeba, algal remains, sponge spicules, and diatoms might be through water intake.     

The Myth of Location Privacy in the United States: Surveyed Attitude Versus Current Practices

In the United States, legal steps have been taken to protect personal privacy, which is viewed as an individual's fundamental right. Location privacy (i.e., protection of personal and location information), however, has not received equal attention in the legal system. Given the recent popularity of location-based services (e.g., cell phones), it is possible to obtain an individual's location information easily and precisely. An investigation of public perception of privacy in the United States indicated that survey responders (1) were unaware of legal implications of location privacy violation and (2) believed that there should be location privacy protection similar to that provided by the Health Insurance Portability and Accountability Act and the Family Educational Rights and Privacy Act.     

Solid state 13C-NMR spectroscopy of some oligocene coals of Assam and Nagaland

Five representative sub-bituminous coals from NE part of India have been analyzed with respect to their distribution of carbon functional groups through ¹³C solid state NMR experiments. The ¹³C Cross Polarised/Magic Angle Spinning NMR spectra of the coal samples were recorded at temperatures of 23°C, 50°C and 70°C respectively and the changes on their structures were interpreted. The NMR spectra of low rank coals were found to exhibit varying degrees of fine structures. The aromaticities of the coal were also determined from the C/H ratios of coal. Some changes in the peak positions along with the formation of simple aromatic units were observed on mild heating.     

Seismic vulnerability assessment of earthquake-prone mega-city Shillong,India using geophysical mapping and remote sensing

ABSTRACT

The concept of seismic vulnerability is a yard-stick of damage estimation from a probable earthquake considering physical cum social dimension and enables a basis for decision-makers to develop preparedness and mitigation strategies. We aim at vulnerability assessment of the typical urban system of capital city Shillong situated on hilly terrain. High-resolution satellite imagery of Shillong facilitates analysis of building footprints, communication network, and open ground. Different building typologies are identified taking into account the building’s structural configuration assessed through a rapid visual survey of more than 15% of total residential households. Slope map demarcates the landslide-prone area through discrete elevation modelling. A methodology incorporating several parameters e.g. building typology, slope angle, shear wave velocity characteristics, geomorphology, and the number of occupants in correlation with a physical measurement of vulnerability is presented and is applied to estimate the dimension of vulnerability. Additionally, MASW survey indicates lithology up to 30?m deep along with the existence of stiff soil and rocks at different depths whereas resonant frequency is identified to be in the range of 6–8?Hz through H/V ratio. Integrating all, it is observed that more than 60% of Shillong city falls under moderate to higher vulnerability and the rest is less vulnerable.     

A GIS-Based Model to Determine Site Suitability of Emergency Evacuation Shelters

In recent years, the increase in the number of hurricanes and other costal hazards in the US pose a tremendous threat to the residents of coastal states. According to the National Hurricane Center, Florida is the most vulnerable coastal state to hurricanes. Mitigation policies have been formulated to reduce mortality and provide emergency services by evacuating people from the hazard zone. Many of these evacuees, particularly the elderly or lower income populations, rely on evacuation shelters for temporary housing. Because of the cost and limited use, evacuation shelters are almost exclusively dual use shelters where the primary purpose of the facility is for some other public function (e.g. school, hospital, etc.). In 2000, the estimated shortage of public shelter spaces in Florida was about 1.5 million. The purpose of this study was to rank the existing and candidate shelters (schools, colleges, churches and community centers) available in the state based on their site suitability. The research questions examined in this study include: (1) How many candidate shelters are located in physically suitable areas (e.g. not in a flood prone area, not near hazardous facilities, etc.)?; (2) How many existing shelters are located in physically un suitable areas, but in socially suitable areas (situated in areas with demand)?; (3) How many alternative existing and/or candidate shelters with high/very high physical suitability are located near physically un suitable existing shelters and thus, may be better choices for a shelter?; and (4) How many existing shelters located in physically un suitable areas are not near alternative existing and/or candidate shelters? A Geographic Information System‐based suitability model integrating Weighted Linear Combination (WLC) with a Pass/Fail screening technique was implemented for the 17 counties of Southern Florida. It was found that 48% of the existing shelters are located in physically unsuitable areas. Out of all the candidate shelters, 57% are located in physically unsuitable areas. For 15 of the existing shelters in unsuitable locations, no alternative candidate or existing shelter with medium to high physical suitability exists within 10 miles (16.1 km).     

“Where is home?” Here and there: transnational experiences of home among Canadian migrants in the United States

Using structured telephone interviews this research focuses on how Canadian migrants living in the United States experience and describe home. We argue that the globalisation of peoples’ lives, transnationalism and the concomitant creation of transnational social spaces have greatly affected the meaning of home for migrants. The understandings of home that result reflect the reality of living in social worlds that span two countries and the development of decentred multiple attachments and feelings of belonging in more than one place. In response to these circumstances Canadian migrants experience home as multi-dimensional, pluri-local, and characterized by regular movement across the U.S.–Canada border. When asked specifically about feeling at home upon re-entry to the U.S. many respondents answered yes. However, many interviewees qualified their answers by describing home in different ways and associating different aspects of their lives with each country. Canada as home was most often described in terms of family, while home in the U.S. was associated with work. Respondents also differentiated between feeling at home once they reached their residence as opposed to feeling unwelcome at the U.S. border.