Volcanic processes and human exposure as elements to build a risk model for Volcan de Fuego, Guatemala

The activity of Fuego volcano during the 1999 - 2013 eruptive episode is studied through field, remote sensing and observatory records. Mapping of the deposits allows quantifying the erupted volumes and areas affected by the largest eruptions during this period. A wide range of volcanic processes results in a diversity of products and associated deposits, including minor airfall tephra, rockfall avalanches, lava flows, and pyroclastic flows. The activity can be characterized by long term, low level background activity, and sporadic larger explosive eruptions. Although the background activity erupts lava and ash at a low rate (~ 0.1 m3/s), the persistence of such activity over time results in a significant contribution (~ 30%) to the eruption budget during the studied period. Larger eruptions produced the majority of the volume of products during the studied period, mainly during three large events (May 21, 1999, June 29, 2003, and September 13, 2012), mostly in the form of pyroclastic flows. A total volume of ~ 1.4 x 108 m3 was estimated from the mapped deposits and the estimated background eruption rate. Posterior remobilization of pyroclastic flow material by stream erosion in the highly confined Barranca channels leads to lahar generation, either by normal rainfall, or by extreme rainfall events. A reassessment of the types of products and volumes erupted during the decade of 1970's allows comparing the activity happening since 1999 with the older activity, and suggests that many of the eruptive phenomena at Fuego may have similar mechanisms, despite the differences in scale between. The deposits of large pyroclastic flows erupted during the 1970's are remarkably similar in appearance to the deposit of pyroclastic flows from the 1999 - 2013 period, despite their much larger volume; this is also the case for prehistoric eruptions. Radiocarbon dating of pyroclastic flow deposits suggests that Fuego has produced large eruptions many times during the last ~ 2 ka, including larger eruptions during the last 500 years, which has important hazard implications. A survey was conducted among the local residents living near to the volcano, about their expectations of possible future crises. The results show that people are aware of the risk they could face in case of a large eruption, and therefore they are willing to evacuate in such case. However, their decision to evacuate may also be influenced by the conditions in which the evacuation could take place. If the evacuation represents a potential loss of their livelihood or property they will be more hesitant to leave their villages during a large eruption. The prospect of facing hardship conditions during the evacuation and in the shelters may further cause reluctance to evacuate. A short discussion on some of the issues regarding risk assessment and management through an early warning system is presented in the last chapter.

Romantic relationships and adjustment in early adulthood: The role of cross-sex experience in the context of social norms and support

Attachment and interpersonal theory suggest a sequential pattern of relationships beginning in the earliest stage of development and progressing to social and eventually romantic relationships. Theoretically, cross-sex experiences have an important role in the progression of interpersonal relationships. Despite the prevalence of these theories about the nature of romantic relationship development, the linkage of cross-sex experience (CSE) to romantic relationships has not been established. Indeed, it is an intuitive assumption, especially within Western society and these theories do not consider socio-cultural factors that may influence CSE and relationship satisfaction. This study addresses the varying contextual factors that may contribute to relationship satisfaction and adjustment, aside from CSE, and is divided into two parts. Study 1, addresses CSE, relationship satisfaction, and adjustment in a unique population, ultra-Orthodox Jews. Among this population, social or romantic CSE is limited and sexes are effectively segregated. Study 2, expanded the study to a larger sample of U.S. college students, to assess the linkage of CSE to romantic relationship satisfaction in a more typical Western population. It included social norm and support variables to address the contextual nature of relationship development and satisfaction. Results demonstrated clear differences in the relation between CSE and relationship satisfaction in the two samples. In the first sample CSE was unrelated to relationship satisfaction; nevertheless, relationship satisfaction was associated with adjustment as it is for more typical populations with greater CSE. These results suggested the importance of specifying how social norms and social support relate to CSE, relationship satisfaction and adjustment. The results from the second sample were consistent with the theoretical framework upon which the social/romantic literature is based. CSE was directly connected to relationship satisfaction. As anticipated, CSE, relationship satisfaction, and adjustment also varied as a function of social norms and support. These findings further validate the influence of socio-cultural factors on relationship satisfaction and adjustment. This study contributes to the romantic relationship literature and broadens our understanding of the complex nature of interpersonal and romantic relationships.^

The role of information literacy competence and higher order thinking skills to develop academic writing in science and engineering students

This article discusses a study organized to develop academic writing skills in undergraduate students pursuing engineering courses. The target group consisted of 30 students pursuing a Bachelor of Technology in their third year. The classroom observations regarding teaching writing revealed that writing proficiency for most of the students was at a very low level. Followed by this, an intervention program was organized in one college, where the researcher taught academic writing to the students. Units comprising tasks that focused on raising awareness of the academic texts and involving the students in the cognitive processes of writing were designed. The study focused on raising student awareness regarding the nature and characteristics of academic texts in order to develop academic writing skills. The study also emphasized that involving the students in the cognitive processes of writing (e.g., defining the rhetorical problem, identifying the rhetorical situation, determining the audience, setting goals for writing, planning for the text by generating, and organizing ideas) is necessary. The study further suggests that discussions between students and teachers regarding the construction of a text and the way language works in various text types facilitates better writing.

Vanadium Redox Flow Battery Storage System Linked to the Electric Grid

This paper focuses on technology state of the art for the charge/discharge of electric energy storage supported by vanadium redox flow battery linked to the electric grid. Properties of vanadium, the main configuration and the reaction of charge/discharge of a vanadium redox flow battery are addressed. The vanadium redox flow battery has the highest cell voltage among the other redox flow battery, implying higher power and energy density which favours application at power plants. This electric energy storage is viewed as a promising contribution to be integrated in power system due to a reasonably bulky size and to successful applications currently allowing storage of energy at power plants or at electrical grids. For instances, allowing storage of energy as an economic improvement providing spin reserve to avoid penalty for imbalances between the energy delivered and energy contracted at closing of electricity market or as an economic improvement to diminish the cost of electricity usage of a consumer. The vanadium redox flow battery has the advantages of scalability customized to meet requirements for power and energy capacity and of excellent combination of energy efficiency, capital cost and life cycle costs compared with other technology.