Illumination effects on electrical characteristics of GaN/AlGaN/GaN heterostructures and heterostructure field effect transistors and their elimination by proper surface passivation

The effect of ambient illumination is investigated for differently processed GaN/AlGaN/GaN heterostructure materials. For samples of the same material with different passivation, the difference in sheet resistance of illuminated and non-illuminated material can be as large as 130% (for annealed heterostructure without passivation) and as small as 3% (for heterostructure passivated with low pressure chemical vapor deposition (LPCVD) silicon nitride). The time constant for the decay of the persistent photoconductance (PPC) is also very different for the differently processed samples. The majority of the effect on the conductance is from photons with energies between 3.1 and 3.7 eV. The investigation indicates that delayed recombination of electrons emitted from surface states and from deep level states in the AlGaN layer dominates the PPC. A theory is formulated by which the difference in illumination sensitivity for the differently passivated materials can be explained by different distributions of electrons between the channel two dimensional electron gas and an accumulation layer formed in the cap layer. For practical heterostructure field effect transistor (HFET) measurements, the illumination sensitivity is generally lower than that of the Hall measurements. Furthermore, HFETs fabricated with the LPCVD silicon nitride passivation are practically illumination invariant

Underlying reasons for career change among graduated equine science students

Equine students labour market – reasons to change career The Swedish University of Agricultural Science offers a variety of courses and educations in the field of agriculture, natural sciences, forestry and environmental science. Equine Science is one of the bachelor programs. It was founded in the year of 1994. According to an inquiry to equine science alumni who graduated throughout the years 1996-2011, more than one fourth of the alumni who answered the inquiry no longer work in the equine sector. This study aims to elucidate the factors leading to the change of vocation among equine science alumni. Therefore, this study can contribute to knowledge about and improvement of working conditions within the equine sector. Prior studies have found that labor market mobility is a complex phenomenon. People deciding to change career have expressed lower rates of satisfaction with their employment. Other reasons to change career was attractive working conditions within the new vocation, better salary, better opportunities to combine work with family, more meaningful work tasks and further possibilities for personal development. This study was performed through semi-structured telephone interviews with eight female equine science alumni who at some point worked outside of the equine sector. The results showed that the physical working environment was tough and strenuous. Several equine science alumni had injuries caused by their work. Half of the respondents thought that there was a problem with collective boards at Swedish riding schools. The main problems concerned cooperation and communication with or within the boards. The psychosocial working environment was negatively influenced by multiple factors, such as different approaches on horse keeping and the welfare of horses, poor leadership and collective boards when working at riding schools. The salaries within the equine sector was considered to be low by the majority of the respondents. The working hours and the possibilities of a normal family life was not considered to be favorable. The majority of the equine science alumni could consider working within the equine sector again if the working conditions became more favorable. The conclusion of this study proves that there is more than one specific reason for equine science alumni to change vocation, such as physical and psychosocial working environment, salary, collective boards and the effects on personal and family life. This can be concluded to the influence of the individuals physical and psychological health. To improve the working conditions within the equine sector stables and yards need renovation and modernization. The leadership and the support from the trade unions are also in need of improvement.Arbetet i häststallar är tungt och innebär bland annat besvärliga arbetsställningar och tunga lyft. Enligt en alumnenkät till hippologer som påbörjat studier vid hippologprogrammet år 1994–2009 där 46% av det totala antalet utexaminerade hippologer svarade, arbetar idag mer än en fjärdedel av hippologalumnerna utanför hästsektorn. Syftet med denna studie är att undersöka bakomliggande orsaker till att hippologer inom ridhästinriktningen väljer att byta yrke efter avslutad universitetsutbildning. Studien kan därmed bidra till att ge insikt i hippologernas arbetsförhållanden och därmed även hur de kan förbättras. Studien baserades på frågeställningarna; Vilka är anledningarna till att hippologer lämnar hästsektorn? Hur uppfattas arbetsförhållandena inom hästsektorn av de som lämnat branschen? Hur skulle branschen kunna utvecklas för yrkesverksamma? Tidigare studier har funnit att rörlighet på arbetsmarknaden är ett komplext fenomen. De personer som valt att byta karriär har generellt sett påvisat en lägre trygghet och tillfredsställelse med arbetet. Andra anledningar till yrkesbyte har visat sig vara attraktiva arbetsförhållanden inom det nya yrkesområdet, högre lön, bättre möjligheter att kombinera arbetet med familjelivet och mer givande arbetsuppgifter. Ett annat skäl att byta yrke var bättre möjligheter till personlig utveckling. Studien utfördes genom semistrukturerade kvalitativa telefonintervjuer med åtta kvinnliga hippologalumner. Intervjupersonerna valdes slumpmässigt ut från klasslistor med hippologer som utexaminerats mellan år 1996–1999. Intervjuerna transkriberades och bearbetades sedan genom fenomenografisk analys. Resultatet visade att den fysiska arbetsmiljön ansågs hård och påfrestande av hippologerna som deltog i studien. Flera hade ådragit sig arbetsskador. Hälften av hippologerna upplevde styrelser som ett problem vid arbete på ridskola. Det som ansågs problematiskt var att styrelserna kunde variera kraftigt från år till år och att det kunde finnas stor oenighet inom styrelserna samt att kommunikationen ofta var bristfällig, såväl inom styrelsen som med personalen. Den psykosociala arbetsmiljön vid arbete i hästsektorn påverkades av flera faktorer. Vid arbete på ridskola påverkades den i stor grad av styrelsen. En annan påverkande faktor var huruvida synen på hästhållning och hantering överensstämde med kollegor och arbetsgivare. Majoriteten av hippologerna ansåg att lönen inom hästsektorn var låg. Arbetstiderna och möjligheterna till ett privatliv utanför arbetet ansågs av vissa hippologer problematiskt. Tre av hippologerna hade redan innan de påbörjade hippologprogrammet andra yrkesdrömmar, vilket påverkade deras beslut om att lämna hästsektorn. Överlag upplevde hippologerna att ledaregenskaper hos chefer inom hästsektorn behövde utvecklas. Majoriteten av hippologerna kunde tänka sig att återgå till hästsektorn om arbetsförhållandena var tillräckligt gynnsamma. Slutsatsen av denna studie är att det finns flera bakomliggande faktorer till att hippologer väljer att byta yrke såsom den fysiska och psykosociala arbetsmiljön, lönen, styrelser och påverkan på privatlivet. Detta kan sammanfattas till arbetets påverkan på individens fysiska och psykiska hälsa. Hästsektorn uppfattas som en rolig men hård bransch av de hippologer som bytt yrke. Modernisering av anläggningar, förbättrat ledarskap samt mer kunniga och aktiva fackförbund är de områden som främst behöver utvecklas för att förbättra arbetsförhållandena inom hästsektorn

Exploring inattention and distraction in the SafetyNet accident causation database

The SafetyNet Accident Causation Database was formulated as part of the SafetyNet Integrated Project. Data were collected in 6 European countries using ‘on-scene’ and ‘nearly on-scene’ crash investigation methods. 32% of crashes recorded in the Database, involved at least one driver, rider or pedestrian, which had been assigned the SNACS codes ‘Inattention’ and/or ‘Distraction’. 212 of the drivers were assigned ‘Distraction’ and 140 drivers were given the code ‘Inattention’. Distraction and Inattention often leads to missed observations and ‘Timing’ or ‘Direction’ critical events. In addition, the type of distraction and inattention differs according to the crash type

Identifying individual-based injury patterns in multi-trauma road users by using an association rule mining method

In many road crashes the human body is exposed to high forces, commonly resulting in multiple injuries. This study of linked road crash data aimed to identify co-occurring injuries in multiple injured road users by using a novel application of a data mining technique commonly used in Market Basket Analysis. We expected that some injuries are statistically associated with each other and form Individual-Based Injury Patterns (IBIPs) and further that specific road users are associated with certain IBIPs. First, a new injury taxonomy was developed through a four-step process to allow the use of injury data recorded from either of the two major dictionaries used to document anatomical injury. Then data from the Swedish Traffic Accident Data Acquisition, which includes crash circumstances from the police and injury information from hospitals, was analysed for the years 2011 to 2017. The injury data was analysed using the Apriori algorithm to identify statistical association between injuries (IBIP). Each IBIP were then used as the outcome variable in logistic regression modelling to identify associations between specific road user types and IBIPs. A total of 48,544 individuals were included in the analysis of which 36,480 (75.1%) had a single injury category recorded and 12,064 (24.9%) were considered multiply injured. The data mining analysis identified 77 IBIPs in the multiply injured sample and 16 of these were associated with only one road user type. IBIPs and their relation to road user type are one step on the journey towards developing a tool to better understand and quantify injury severity and thereby improve the evidence-base supporting prioritisation of road safety countermeasures

Identifying the causes of road crashes in Europe

This research applies a recently developed model of accident causation, developed to investigate industrial accidents, to a specially gathered sample of 997 crashes investigated in-depth in 6 countries. Based on the work of Hollnagel the model considers a collision to be a consequence of a breakdown in the interaction between road users, vehicles and the organisation of the traffic environment. 54% of road users experienced interpretation errors while 44% made observation errors and 37% planning errors. In contrast to other studies only 11% of drivers were distracted and 8% inattentive. There was remarkably little variation in these errors between the main road user types. The application of the model to future in-depth crash studies offers the opportunity to identify new measures to improve safety and to mitigate the social impact of collisions. Examples given include the potential value of co-driver advisory technologies to reduce observation errors and predictive technologies to avoid conflicting interactions between road users

“Det blev ju lite mer… riktigt socialt arbete” : En kvalitativ studie om socialsekreterares upplevelser av sin arbetsinsats under en krissituation

The aim of this study was to examine the experiences of social workers working with unaccompanied refugee minors during the autumn of 2015, commonly referred to as the “refugee crisis”. During this period, Sweden received approximately 156 400 refugees, putting Sweden’s social infrastructure under enormous pressure. As a result of the stressful working conditions, a large amount of social workers left the social services. This study however, focuses on the experiences of social workers choosing to stay during and after this period, aiming to identify their working conditions, coping strategies as well as their ability to remain professional. The focus of the study was to examine whether the social workers felt they were able to execute their tasks professionally when forced to operate in a stressful situation, as well as how they perceived the situation affected their ability to remain professional. Empirical data was collected with semi-structured interviews with five social workers, operative in the greater Stockholm area during the autumn of 2015. The empirical data was interpreted and analysed through a theory of coping strategies in social work. The study reached the conclusion that the utilization of different coping strategies enabled a sense of accomplishing ”real social work” where respondents perceived that they reached the “core purpose” of social work. However, the situation also created negative effects, for example in terms of legal security

Does injury pattern among major road trauma patients influence prehospital transport decisions regardless of the distance to the nearest trauma centre? – a retrospective study

Prehospital undertriage occurs when the required level of care for a major trauma patient is underestimated and the patient is transported to a lower-level emergency care facility. One possible reason is that the pattern of injuries exceeding a certain severity threshold is not easily recognizable in the field. The present study aims to examine whether the injury patterns of major road trauma patients are associated with trauma centre transport decisions in Sweden, controlling for the distance from the crash to the nearest trauma centre and other patient characteristics. The Swedish Traffic Accident Data Acquisition (STRADA) database was queried from April 2011 to March 2017. Teaching hospitals with neurosurgery capabilities were classified as trauma centres (TC), all other hospitals were classified as other emergency departments (ED). Injury Severity Score ≥ 13 was used as the threshold for major trauma. Ten common injury patterns were derived from the STRADA data; six patterns included serious neuro trauma to the head or spine. The remaining four patterns were: other severe injuries, moderate to serious abdomen injuries, serious thorax injuries and all other remaining injury patterns. Logistic regression was used to analyse the effect of injury patterns, age, sex and distance from crash to nearest TC on transport decision (TC or ED). Of the 2542 patients, 38.0% were transported to a TC, equating to a prehospital undertriage of 62%. Over half (59.4%) of the patients had four or more Abbreviated Injury Scale (AIS) 2+ injuries. After controlling for age, sex and distance to nearest TC, only patients sustaining serious head injuries together with other severe injuries had significantly higher odds of being transported to a TC (OR = 4.18, 95% CI: 2.03, 8.73). The odds of being transported to a TC decreased by 5% with every kilometre further away the crash location was to the nearest TC. These results highlight that there is considerable prehospital undertriage in Sweden and suggest that distance to nearest TC is more influential in transport decisions than injury pattern. These results can be used to further develop prehospital transportation guidelines and designation of trauma centres

The Great Acceleration is real and provides a quantitative basis for the proposed Anthropocene Series/Epoch

The Anthropocene was conceptualized in 2000 to reflect the extensive impact of human activities on our planet, and subsequent detailed analyses have revealed a substantial Earth System response to these impacts beginning in the mid-20th century. Key to this understanding was the discovery of a sharp upturn in a multitude of global socio-economic indicators and Earth System trends at that time; a phenomenon termed the ‘Great Acceleration’. It coincides with massive increases in global human-consumed energy and shows the Earth System now on a trajectory far exceeding the earlier variability of the Holocene Epoch, and in some respects the entire Quaternary Period. The evaluation of geological signals similarly shows the mid-20th century as representing the most appropriate inception for the Anthropocene. A recent mathematical analysis has nonetheless challenged the significance of the original Great Acceleration data. We examine this analytical approach and reiterate the robustness of the original data in supporting the Great Acceleration, while emphasizing that intervals of rapid growth are inevitably time-limited, as recognised at the outset. Moreover, the exceptional magnitude of this growth remains undeniable, reaffirming the centrality of the Great Acceleration in justifying a formal chronostratigraphic Anthropocene at the rank of series/epoch