Middle years of schooling: the pressures on rural adolescents to achieve academically

Within a climate of continual change this study offers insights into the academic pressures experienced by rural adolescents to achieve at school. In the often challenging transition from childhood to adulthood expectations from others place additional pressures on adolescents' lives. To better understand these pressures, I conducted a qualitative study of six students (ages nine to 15) and their teachers in the Middle Years of Schooling within rural Victoria, Australia. Students were studied prior to the Victorian Certificate of Education (VCE) in order to examine the pressures on students facing the Middle Years of Schooling. The study was carried out over a 6 month period using a Naturalistic Inquiry process with semi-structured interviews and participant observation. This allowed access into the participants' subjective insights. A Collective case study approach was employed to situate the information in its holistic environment and offer thick and information rich narratives depicting the experiences of these early adolescents. The case studies also involved examination of the school experiences of the early adolescents. Academic pressure was then broadly viewed in light of these experiences and recommendations offered. The findings from this research revealed that the early adolescents in the study all experienced degrees of academic pressure and demonstrated varied abilities to cope with these pressures. External support provided by parents, the school, teachers and peers tended to provide support more than fostering resilience

Analysis of Fatigue Crack Propagation in Welded Steels

This thesis presents the study of fatigue crack propagation in a low carbon steel (ASTM A36) and two different weld metals (AWS A5.18 and AWS A5.28). Fatigue crack propagation data for each weld wire is of interest because of its use for predicting and analyzing service failures. Fatigue crack growth test specimens were developed and fabricated for the low carbon steel base metal and for each weld wire. Weld specimens were stress relieved prior to fatigue testing. Specimens were tested on a closed-loop servo hydraulic test machine at two different load ratios. Fatigue test data was collected to characterize both Region I and Region II crack propagation for each material. Test materials were characterized and fracture surfaces were analyzed. Experimental test results were compared to fatigue striation measurements taken using a scanning electron microscope (SEM). Region II fatigue crack propagation data for ASTM A36 was found to be in agreement with existing R=0.05 and R=0.6 data for ferritic-pearlitic steels. Region II fatigue crack propagation data for weld metal was generally the same as ASTM A36 and within the limits of other weld metals. Scanning electron microscopy of the Region II fracture surfaces showed that they all exhibited similar fracture features (striations), indicating that the crack propagation mechanism was the same in all cases. Region I fatigue crack propagation data resulted in higher ∆K_thvalues for AWS A5.18 as compared to AWS A5.28. ∆K_thvalues for ASTM A36 were in agreement with published values for mild steel. ∆K_thvalues were greater for load ratios R=0.05 as compared to R=0.6. The greater ∆K_th values for R=0.05 are thought to be caused by crack closure. ∆K_th values for ASTM A36 and AWS A5.18 were greater than those of AWS A5.28. The grain structure of AWS A5.28 was found to be finer than those of ASTM A36 and AWS A5.18 and is thought to be the cause of the lower ∆K_th values

O Z-Degree de Tidewater e o modelo INTRO para a Adoção Sustentável dos REA

A growing body of research confirms the financial and academic benefits that accrue to students whose faculty adopt open educational resources, or OER. While there are no content licensing costs associated with using OER, there are several real costs that must be incurred by an institution that chooses to support its faculty in adopting OER. The Z-Degree initiative at Tidewater Community College utilizes only OER for the 21 courses, providing a pathway for students to earn an associate of science degree in business administration without ever buying a textbook. The authors introduce and illustrate the INTRO (INcreased Tuition Revenue through OER) model for sustaining the provision of OER adoption services. The adoption of OER as part of the Z-Degree decreases drop rates among Tidewater students, allowing the institution to retain tuition revenue it would otherwise have refunded. This retained revenue provides a renewable source of funds to sustainably support the adoption of OER.Un creciente cuerpo de investigaciones reafirman los beneficios económicos y académicos que reportan sobre los estudiantes universitarios el uso de recursos educativos abiertos (REA) por parte de sus docentes. Sin embargo, las instituciones que deciden apoyan a sus docentes en el uso de REA tienen que asumir una gran cantidad de costes reales, a pesar de no contar con costes asociados a las licencias de contenido. La iniciativa Z-Degree llevada a cabo por la Tidewater Community College utiliza solo REA en 21 asignaturas del Diploma de Asociado en Ciencias de Administración de Empresas, proporcionando una vía para que los estudiantes puedan obtener el título universitario sin tener que comprar un solo libro de texto. Los autores presentan e ilustran el modelo Aumento de los Ingresos por Matrículas a través de REA (INTRO, por sus siglas en inglés) para sostener la prestación de servicios que supone la adopción de los REA. La adopción de los REA como parte de la Z-Degree disminuye las tasas de abandono entre los estudiantes Tidewater, lo que permite a la institución mantener los ingresos por las matrículas. Esta retención de ingresos proporciona una fuente renovable de fondos para apoyar de forma sostenible la adopción de los REA.Um crescente corpo de pesquisa confirma os benefícios financeiros e acadêmicos que para os alunos cujos professores adotam recursos educacionais abertos, ou REA. Ainda que não há nemhum custo de licença de conteúdo associado com usar REA, sim há custos reais que devem ser incorridos por uma institucao que decide apoiar sua faculdade na adoção dos REA. A iniciativa de Z-Degree, em Tidewater College utiliza apenas REA para os vinte-uns cursos porem provendo um caminho para que os alunos ganham uma diploma de Associate’s de ciencia em administração de empresas sem nunca compra um livro. Os autores apresentam e ilustram o INTRO (Increased Tuition Revenue atraves de REA) modelo para sustentar a prestação de serviços para a adoção dos REA. A adoção de REA como parte do Z-Degree diminui taxas de abandono entre os alunos de Tidewater, permitindo que a instituição retenha a receita de matrícula que em outra situação teria devolvido. Este receita retida fornece uma fonte renovável de fundos para apoiar de forma sustentável a adopção de REA

Metodologie magneto-gradiometriche applicate ad indagini marine di tipo ambientale all’interno del Mar Piccolo (Taranto)

La caratteristica fondamentale dei metodi di potenziale, è quella di aver il pregio di fornire una risposta relativamente rapida e non invasiva dell’oggetto in studio, che siano strutture geologiche (studi di tipo tettonico o minerario) o isolati corpi suscettivi sepolti (studi prettamente ambientali – relitti, discariche sottomarine, fusti metallici sepolti ecc..). Nei rilievi magnetici marini relativi a quest’ultimo caso, per ottenere dei risultati soddisfacenti, sono di fondamentale importanza alcuni requisiti quali un accurato sistema di posizionamento GPS, l’utilizzo di vettori navali amagnetici, una elevata sensibilità della strumentazione impiegata, e la corretta rimozione degli effetti temporali legati alle variazioni del Campo Magnetico terrestre. Quest’ultimo aspetto è assai delicato perché comporta la necessità di avere un osservatorio fisso coerente in misura durante l’esecuzione del rilievo. Per superare questo problema sono assai efficaci metodologie di tipo gradiometrico, che si basano sullo studio del gradiente orizzontale del Campo Magnetico terrestre, che si ottiene mediante l’acquisizione contemporanea di due misure (due sensori) poste ad una determinata distanza tra loro. I principali vantaggi introdotti dall’utilizzo di queste tecniche consistono principalmente in una significativa attenuazione dei contributi derivanti dalle sorgenti più profonde, la non necessità delle correzioni temporali ed in una maggiore rapidità nelle procedure di elaborazione dei dati. In questa ottica è stato condotto uno studio applicando questo tipo di metodologia in un contesto prettamente ambientale ovvero l’individuazione di corpi metallici in un’area ad elevato noise ambientale. L’area del rilievo è situata all’interno del Mar Piccolo di Taranto, a ridosso delle strutture portuali e si estende per circa 3 X 1,5 Km. I rilievi sono stati condotti utilizzando una piccola imbarcazione (idrobarca in GRP - Glass Renforced Plastic) trainante l’apparato di misura filato ad una distanza tale da non risentire del disturbo elettromagnetico generato dai motori e dalle apparecchiature di bordo. Problematiche relative ai bassi fondali dell’area rilevata (da 4 a 13 metri di battente d’acqua) hanno comportato la progettazione di un apposito catamarano in vetroresina (completamente amagnetico) a cui è stata fissata la sensoristica, così da poter navigare poco sotto il pelo dell’acqua; per motivi di navigabilità sono stati pianificate rotte principali in direzione Est-Ovest e traverse di controllo nelle aree con segnali ‘interessanti’. La strumentazione magnetometrica utilizzata (fig. 1) è costituita da due sensori a vapori di Cesio che sfruttano la tecnica del pompaggio ottico. La misura della frequenza viene effettuata con 10 letture al secondo, l’operatività è garantita in un range tra 20.000 – 100.000 nT e l’accuracy assoluta dipende da diversi fattori quali: l’orientazione del sensore, lo shift della luce interna e il tempo del frequency counter. L’errore dovuto all’orientazione risulta comunque compreso entro 1 nT. L’operatività viene garantita in un range da –35° e +50° di orientazione dei sensori. la sensibilità è di 0.02 nT con un intervallo di campionamento di 10 misure al secondo. Nonostante l’elevato noise ambientale causato dalla presenza di navi, bacini e altre sorgenti di noise legate alle attività portuali, sono stati evidenziati 9 punti anomali di interesse nella mappa del segnale gradiometrico (fig. 2). Le successive ispezioni dirette, hanno rilevato la presenza di evidenze (vari materiali di tipo ferroso e spezzoni di battelli) correlate alle anomalie di 7 punti tra quelli individuati a seguito dell’elaborazione dei dati

Holocene Sea Level Recorded by Beach Rocks at Ionian Coasts of Apulia (Italy)

Beach rocks are located along many coasts of the Mediterranean basin. The early diagenesis environment and the mean sea level along the shoreline make these landforms useful in the reconstruction of relative sea-level changes and, in particular, as SLIPs (sea-level index points). The beach rocks surveyed along the Ionian coast of Apulia were found to be well preserved at three specific depth ranges: 6–9 m, 3–4 m, and from the foreshore to about 1.20 m. Morpho-bathymetric and dive surveys were performed to assess both the geometries and the extension of the submerged beach rocks. Samples were collected at these different depths in the localities of Lido Torretta, Campomarino di Maruggio, San Pietro in Bevagna, and Porto Cesareo. Bivalve shells were identified and isolated from the beach rock samples collected at a depth of 7 m; AMS dating provided a calibrated age of about 7.8 ka BP. Their morphology and petrological features, along with the time constraints, enabled us to (i) reconstruct the local sea-level curve during the Holocene, (ii) corroborate acquired knowledge of the relative sea-level history, and (iii) identify possible local vertical land movement (VLM)

Geomorphology and development of a high-latitude channel system: the INBIS channel case (NW Barents Sea, Arctic)

This is a post-peer-review, pre-copyedit version of an article published in Arktos. The final authenticated version is available online at: http://dx.doi.org/https://doi.org/10.1007/s41063-019-00065-9 .The INBIS (Interfan Bear Island and Storfjorden) channel system is a rare example of a deep-sea channel on a glaciated margin. The system is located between two trough mouth fans (TMFs) on the continental slope of the NW Barents Sea: the Bear Island and the Storfjorden–Kveithola TMFs. New bathymetric data in the upper part of this channel system show a series of gullies that incise the shelf break and minor tributary channels on the upper part of the continental slope. These gullies and channels appear far more developed than those on the rest of the NW Barents Sea margin, increasing in size downslope and eventually merging into the INBIS channel. Morphological evidence suggests that the Northern part of the INBIS channel system preserved its original morphology over the last glacial maximum (LGM), whereas the Southern part experienced the emplacement of mass transport glacigenic debris that obliterated the original morphology. Radiometric analyses were applied on two sediment cores to estimate the recent (~ 110 years) sedimentation rates. Furthermore, analysis of grain size characteristics and sediment composition of two cores shows evidence of turbidity currents. We associate these turbidity currents with density-driven plumes, linked to the release of meltwater at the ice-sheet grounding line, cascading down the slope. This type of density current would contribute to the erosion and/ or preservation of the gullies’ morphologies during the present interglacial. We infer that Bear Island and the shallow morphology around it prevented the flow of ice streams to the shelf edge in this area, working as a pin (fastener) for the surrounding ice and allowing for the development of the INBIS channel system on the inter-ice stream part of the slope. The INBIS channel system was protected from the burial by high rates of ice-stream derived sedimentation and only partially affected by the local emplacement of glacial debris, which instead dominated on the neighbouring TMF systems

Observational Evidence of the Basin-Wide Gyre Reversal in the Gulf of Taranto

The paper shows for the first time the observational evidence of basin-wide gyre reversal in the Gulf of Taranto (north-western Ionian Sea in the eastern Mediterranean Sea) by means of two specifically designed in situ oceanographic campaigns (based on CTD and ADCP measurements). The analysis of the in situ data shows a change in circulation from anticyclonic in October 2014 to cyclonic in June\u2013July 2016. Furthermore, long-term (1993\u20132018) analysis using gridded satellite altimetry data in the Gulf of Taranto shows that the cyclonic gyres are more frequent than anticyclonic gyres. The latter occur only for 2 to 3 years at a time in some decades