Measurements of emissions for lpg combustion within a porous cylindrical burners

CO and NO[x] emission characteristics of a hollow cylindrical radiation burner operated in the external and internal combustion modes and premixed LPG+air mixtures are experimentally studies. The influence of the pore structure, equivalence ratio, firing rate and burner design are considered

Плазмодинамический синтез ультрадисперсных фаз системы Ti-B

Objective: The study evaluates exposure to the cold of personnel involved in helicopter rescue operations in an alpine environment. Methods: Rescue operations over a period of 15 months in the Oberwallis region (Switzerland) were analysed with special regard to the weather conditions, the locality and its altitude, and the duration. The equivalent chill temperature was estimated with two independent models. 'Mean exposure' as well as the 'worst-case situation' (based on maximum windspeed) were calculated. The results were evaluated according to the 'classic' Siple-Passel model, the more recent model of Danielsson, ISO 11079, ISO 9920, the German industrial standard DIN 33403.5, and the German government regulations for work in cold environments ('G21'). Results: The temperature models showed only marginal differences in chill temperature. Assuming 'worst-case conditions', the Siple-Passel model showed that 87.1 % of the operations occurred at chill temperatures >-30degreesC, 12.1% in the range of -30 to -45degreesC, and 0.8% at 5% risk, 6% with >50% risk and 1.8% with >95% risk. According to DIN 33403.5, 1.5% of the operations were performed at chill temperatures higher than cold class 1: 2.3% are class 1, 13.3% class 2, 34.7% class 3, 34.6% class 4 and 13.7% class 5. The maximum exposure times of DIN 33404.5 are exceeded in at least 0.5% of the missions. According to ISO 11079, clothing with 2.0 clo is sufficient in 40.2 and 23.9% of the operations [summer, required clothing insulation (IREQ) min. and IREQ neutr., respectively]. In winter the corresponding results are 0.3 and 0.0%. Duration of limited exposure is exceeded in 9.1 (IREQ min.) and 19.8% (IREQ neutr.) of the operations in summer and in 10.3 and 19.8% in winter. According to ISO 9920, ICL min. as well as ICL neutr. is exceeded in 100% in summer and winter operations. Conclusions: Alpine rescue operations are typical of a place of work in a cold-sometimes extremely cold-environment. Because of the limited time of exposure during the majority of the operations, the most important danger for rescue personnel is frostbite, although hypothermia cannot be excluded in cases of prolonged operations. Special advice to avoid the specific risks must be given to the crews and an examination by occupational medicine, e.g. according to 'Working in cold environments, G21' of the German Berufsgenossenschaften, is recommended. Recommendations for adequate clothing are given

Does Modern Helicopter Construction Reduce Noise Exposure in Helicopter Rescue Operations?

Background: During helicopter rescue operations the medical personnel are at high risk for hearing damage by noise exposure. There are two important factors to be taken into account: first, the extreme variability, with some days involving no exposure but other days with extreme exposure; second, the extreme noise levels during work outside the helicopter, e.g. during winch operations. The benefit of modern, less noisier constructions and the consequences for noise protection are still unknown. Objectives: We estimated the noise exposure of the personnel for different helicopter types used during rescue operations in the Alps and in other regions of the world with special regard to the advanced types like Eurocopter EC 135 to compare the benefit of modern constructions for noise protection with earlier ones. Methods: The rescue operations over 1 year of four rescue bases in the Alps (Raron and Zermatt in Switzerland; Landeck and Innsbruck in Austria, n = 2731) were analyzed for duration of rescue operations (noise exposure). Noise levels were measured during rescue operations at defined points inside and outside the different aircraft. The setting is according to the European standard (Richtlinie 2003/10/EG Amtsblatt) and to Class 1 DIN/IEC 651. With both data sets the equivalent noise level Leq8h was calculated. For comparison it was assumed that all rescue operations were performed with a specific type of helicopter. Then model calculations for noise exposure by different helicopter types, such as Alouette IIIb, Alouette II ‘Lama', Ecureuil AS350, Bell UH1D, Eurocopter EC135, and others were performed. Results and conclusions: Depending on modern technologies the situation for the personnel has been improved significantly. Nevertheless noise prevention, which includes noise intermissions in spare time, is essential. Medical checks of the crews by occupational medicine (e.g. ‘G20' in Germany) are still mandator

Does Modern Helicopter Construction Reduce Noise Exposure in Helicopter Rescue Operations?

Background: During helicopter rescue operations the medical personnel are at high risk for hearing damage by noise exposure. There are two important factors to be taken into account: first, the extreme variability, with some days involving no exposure but other days with extreme exposure; second, the extreme noise levels during work outside the helicopter, e.g. during winch operations. The benefit of modern, less noisier constructions and the consequences for noise protection are still unknown. Objectives: We estimated the noise exposure of the personnel for different helicopter types used during rescue operations in the Alps and in other regions of the world with special regard to the advanced types like Eurocopter EC 135 to compare the benefit of modern constructions for noise protection with earlier ones. Methods: The rescue operations over 1 year of four rescue bases in the Alps (Raron and Zermatt in Switzerland; Landeck and Innsbruck in Austria, n = 2731) were analyzed for duration of rescue operations (noise exposure). Noise levels were measured during rescue operations at defined points inside and outside the different aircraft. The setting is according to the European standard (Richtlinie 2003/10/EG Amtsblatt) and to Class 1 DIN/IEC 651. With both data sets the equivalent noise level Leq8h was calculated. For comparison it was assumed that all rescue operations were performed with a specific type of helicopter. Then model calculations for noise exposure by different helicopter types, such as Alouette IIIb, Alouette II ‘Lama', Ecureuil AS350, Bell UH1D, Eurocopter EC135, and others were performed. Results and conclusions: Depending on modern technologies the situation for the personnel has been improved significantly. Nevertheless noise prevention, which includes noise intermissions in spare time, is essential. Medical checks of the crews by occupational medicine (e.g. ‘G20' in Germany) are still mandator

The Road to a Top Ranking A Complexity-Oriented View on the Development of Countries:The Netherlands, Singapore, and Switzerland compared

The Netherlands, Singapore, and Switzerland have long been high in international rankings of prosperity and well-being. Other countries struggle to achieve success, and some even fall into decline. This research project examines how countries rise to the top and remain in an ever-changing world. What gives them the energy and makes them adaptive? What role do governments play in this? What can administrators do to keep their countries energized and adaptive, from government leaders to members of parliament? When selecting countries, similarities in size and institutional-organizational differences were important criteria. In Singapore, central control prevails, while decentralized self-organization is characteristic in Switzerland. In the Netherlands, there is a mix of both systems. The research reveals that variations in applying these guiding principles are not decisive in achieving top positions. The distinction lies in the interaction between the network architecture, the initial conditions of a country system, and the organization of energy management in the three countries.<br/

The Road to a Top Ranking A Complexity-Oriented View on the Development of Countries:The Netherlands, Singapore, and Switzerland compared

The Netherlands, Singapore, and Switzerland have long been high in international rankings of prosperity and well-being. Other countries struggle to achieve success, and some even fall into decline. This research project examines how countries rise to the top and remain in an ever-changing world. What gives them the energy and makes them adaptive? What role do governments play in this? What can administrators do to keep their countries energized and adaptive, from government leaders to members of parliament? When selecting countries, similarities in size and institutional-organizational differences were important criteria. In Singapore, central control prevails, while decentralized self-organization is characteristic in Switzerland. In the Netherlands, there is a mix of both systems. The research reveals that variations in applying these guiding principles are not decisive in achieving top positions. The distinction lies in the interaction between the network architecture, the initial conditions of a country system, and the organization of energy management in the three countries.<br/

The Road to a Top Ranking A Complexity-Oriented View on the Development of Countries:The Netherlands, Singapore, and Switzerland compared

The Netherlands, Singapore, and Switzerland have long been high in international rankings of prosperity and well-being. Other countries struggle to achieve success, and some even fall into decline. This research project examines how countries rise to the top and remain in an ever-changing world. What gives them the energy and makes them adaptive? What role do governments play in this? What can administrators do to keep their countries energized and adaptive, from government leaders to members of parliament? When selecting countries, similarities in size and institutional-organizational differences were important criteria. In Singapore, central control prevails, while decentralized self-organization is characteristic in Switzerland. In the Netherlands, there is a mix of both systems. The research reveals that variations in applying these guiding principles are not decisive in achieving top positions. The distinction lies in the interaction between the network architecture, the initial conditions of a country system, and the organization of energy management in the three countries.<br/

A Lagrangian framework for detecting and characterizing the descent of foehn from Alpine to local scales

When foehn winds surmount the Alps from the south, they often abruptly and vigorously descend into the leeside valleys on the Alpine north side. Scientists have long been intrigued by the underlying cause of this pronounced descent. While mountain gravity waves and the hydraulic theory provide theoretical foundations to explain the phenomenon, the descent of the Alpine south foehn has, so far, not been explicitly quantified and characterized for a series of real-case events. To fill this research gap, the present study employs kilometer-scale numerical simulations, combined with online trajectories calculated during model integration. In an innovative approach, we adopt the Lagrangian perspective, enabling us to identify the descent and determine its key characteristics across foehn regions spanning from the Western to the Eastern Alps. In the first part of the study, we find the descent of foehn air parcels to be primarily confined to distinct hotspots in the immediate lee of local mountain peaks and chains, underlining the fundamental role of local topography in providing a natural anchor for the descent during south foehn. Consequently, the small-scale elevation differences in the underlying terrain are clearly linked to the magnitude of the descent, whereby other contributing factors also influence the process. Combined with the fact that the descent is mostly dry adiabatic, these results suggest that the descending motion occurs along downward-sloping isentropes associated with gravity waves. A small proportion of air parcels experience diabatic cooling and moisture uptake during the descent, which predominantly occur to the south of the Alpine crest. The second part of the study aims to elucidate the different factors affecting the descent on a local scale. To this end, a particularly prominent hotspot situated along the Rätikon, a regional mountain range adjacent to the Rhine Valley, is examined in two detailed case studies. During periods characterized by intensified descent, local peaks along the Rätikon excite gravity waves that are linked to the descent of air parcels into the northern tributaries of the Rätikon and into the Rhine Valley. The two case studies reveal that different wave regimes, including vertically propagating waves, breaking waves, and horizontally propagating lee waves, coincide with the descent. This suggests the absence of a specific wave regime that is consistently present during foehn descent periods along the Rätikon. In addition to gravity waves, other effects likewise influence the descent activity. For example, a topographic concavity deflects the near-surface flow and thus promotes strong descent of air parcels towards the floor of the Rhine Valley. In addition, in one of our cases, nocturnal cooling introduces a smooth virtual topography that inhibits the formation of pronounced gravity waves and impedes the descent of foehn air parcels into the valley atmosphere. In summary, this study approaches a long-standing topic in foehn research from a new angle. Given the limitations of our model simulations, we did not attempt to unequivocally resolve the causes for the descent. Nevertheless, using online trajectories, we explicitly identified and characterized the descent of foehn. The innovative Lagrangian method enabled us to diagnose descent within a comprehensive dataset, encompassing multiple case studies and a wide range of different foehn regions. The findings highlight the benefits offered by the Lagrangian perspective, which not only complements but also substantially extends the previously predominant Eulerian perspective on the descent of foehn.</p

Social Work Field Education and Supervision: What a Global Pandemic Taught Us

Social work field education programs have experienced changes throughout time, including adaptations to supervision of students in field education settings. Monitoring and developing field education supervision is an essential component of ensuring high-quality practicum experiences and satisfaction among both social work students and field instructors. Most recently, the COVID-19 global pandemic led most social work students and field instructors to a rapid shift in practicum placements from in-person to virtual learning; within the process, supervision changed as well. This study includes feedback from a small group of BSW students, MSW students, and field instructors regarding this transition in placement and supervision. The study’s framework investigated the modalities of supervision used, as well as perceptions of the quality of supervision, both before and after the adjustments resulting from the COVID-19 pandemic. Supervision approaches used were developmental, didactic, strengths-based, and trauma-focused. Research findings will be used to enhance BSW and MSW field education within this specific Midwestern university and will aim to provide considerations and recommendations for the development of field education programs in other social work education programs