Structured packings for use in oxygen service: Flammability considerations

Metallic structured packings have found increasing use in the cryogenic distillation of air. An experimental program was performed to test the flammability of selected metal packings under simulated high oxygen concentration operating conditions. Aluminum flammability in gaseous oxygen has been shown to be very dependent upon argon dilution, and in the presence of liquid oxygen, strong energy releases have been observed. Brass packing exhibited an unexpectedly high relative flammability whereas copper has been found to be non-flammable in all tested oxygen purities. These findings suggest the use of copper structured packing in higher purity GOX/LOX regions of an air separation distillation column and aluminum structured packing in the remainder of the column.     

The process safety impact of distributed control systems

Experience has shown that a Distributed Control System (DCS) can provide enhanced process monitoring and control capabilities, as well as system self-diagnostics, that permit increased safety of process operations. However, this enhanced safety does not come about automatically with the installation of a DCS. The complexity and versatility of the DCS can introduce new failure scenarios leading to process upset and potential relization of process hazards. This paper reviews some novel considerations that should be taken into account when conducting process hazards reviews on facilities controlled by a DCS.     

An approach to evaluate the acute impacts from simulated accidental releases of chlorine and ammonia

The manner in which specific chemicals are used is studied in order to identify plausible release scenarios and the probability of their occurrence.     

Applications of amine gelling agents in fire technology

A novel gelatin system for use in oil spills at sea provides rapid immobilization of liquids upon demand.     

Prediction of decomposition limits for ethylene oxide-nitrogen vapor mixtures

A decomposition limit equation applicable to liquid ethylene oxide storage conditions based on recently obtained data is presented. Comparison is made with a second correlation equation developed from literature data. Adjustment of predicted decomposition limits to produce recommended safe operating limits is discussed.     

Laboratory and large-scale dust explosion research

This paper describes dust explosibility research in full-scale experimental mines and a 20-L laboratory chamber at the U.S. Bureau of Mines and in a 1-m³ laboratory chamber at Fike Corporation. The purpose of this research is to improve safety in mining and other industries that manufacture, process, or use combustible dusts. As part of this work, carbonaceous dusts with a wide range of volatilities and various particle size distributions were studied. Laboratory data on the minimum explosible concentrations of predispersed dusts were comparable to mine data for nominal dust loadings that were dispersed by the aerodynamic disturbance from a gas ignition zone. Recommendations are given on the limitations of small-scale testing such as “overdriving” by too strong of an ignitor. The effect of dust particle size on explosibility data is illustrated for coal and aluminum dusts. For both dusts, the finest sizes were the most hazardous. The inerting requirements for preventing explosions were also measured in both laboratory and large-scale systems. All the data show relatively good agreement between the laboratory and the large-scale tests.     

Can the North American ski industry attain climate resiliency? A modified Delphi survey on transformations towards sustainable tourism

As global temperatures increase, does accelerating climate change represent an existential crisis or a manageable challenge for the ski industry? Despite considerable evidence demonstrating the global ski industry is in the early stages of a climate-induced transition, global research on ski industry stakeholder perspectives shows varied levels of climate risk awareness, a focus on future vulnerability, and limited engagement in adaptation. Within North America, research has focussed on the physical climatic impacts to ski operations and possible skier responses, yet there lacks insight into industry perceptions on current and future climate vulnerability. This study fills this important knowledge gap using a Delphi survey to engage 52 leaders from across the continent in a dialogue on strategic climate responsiveness. Results demonstrate North American ski industry leaders’ climate risk perceptions range widely, and opinions diverge over if or how to respond at both an industry and destination scale. Simultaneously, industry experts believe mountain tourists increasingly value nature-based activities, place-bound products, and corporate responsibility. Analysing industry leaders’ responses through Enlightened Stakeholder theory highlights how aligning supply-side environmental management with demand-side tourist experiences may create opportunities for new partnerships, innovations, policies, and strategies needed to achieve climate-resilient and sustainable futures.     

Economic development lessons from and for North American Indian economies*

This paper reviews the literature on economic development as it relates to indigenous people in the United States and Canada, and focuses on how institutions affect economic development of reservation and reserve economies. Evidence shows that strong property rights to reservation and reserve land and natural resources, whether communal or individual, are and always have been important determinants of productivity. Political and legal institutions that are perceived as stable and predictable to tribal members and to non‐Natives also improve economic opportunities for indigenous people living on reservations and reserves. Research reviewed here also shows that culture and acculturation are important in the development process. Although our emphasis is on North America, the findings are applicable to indigenous people in other parts of the world and shed light on growth questions that loom large for developing countries around the world.     

Host tourism aspirations as a point of departure for the sustainable livelihoods approach

The sustainable livelihoods (SL) approach offers a holistic framework and a practical toolkit to analyze tourism's impacts and interactions within a community. This study argues that the usefulness of the SL approach in tourism can be enhanced by ensuring that the approach is built on a genuine people-centered starting point. The exploration of the local community's representations of, and aspirations for, their roles in tourism as a future livelihood choice meets this need. To verify the value of this approach empirically, this study examined the case of Lhasa, Tibet, and local youth as the research respondents. The findings suggest that the young hosts in Lhasa urban area were heterogeneous in their responses to tourism as a future livelihood choice. They fell into four subgroups: in-betweeners, ambivalent supporters, alternative supporters, and lovers. Further, this study examined the profiles of these four subgroups and explored their responses. The study enhances the SL approach by taking tourism as an example and clearly defining the departure point for its adoption within the context of broader livelihoods portfolios. Additionally, it suggests some potential directions for tailored management strategies to meet youth and community perspectives.