45 research outputs found
Rethinking the design of a 2-methoxy-2-methyl-heptane process by unraveling the true thermodynamics and kinetics
No full textAmong other fuel additives — such as MTBE, ETBE, or TAME — 2-methoxy-2-methyl heptane (MMH) can increase the fuel octane number and reduce the CO emission. MMH can be obtained through the exothermal etherification of 2-methyl-1-heptene and methanol. Lately, many researchers have developed more and more efficient processes considering the kinetics corresponding to an endothermal reaction. However, in this work we demonstrate that the reaction is actually quite exothermal, and this has strong impact on the designed process. Also, the vapor–liquid equilibrium data predicted by UNIQUAC model for 2-methoxy-2-methyl heptane and 2-methyl-2-heptanol mixture reveals that product purification is more difficult, and it requires more energy to recover and obtain MMH with high purity. Considering these aspects, the 54.87 ktpy process developed in this paper is more realistic and energy intensive (1.82 kW h/kg MMH), with a TAC of 5.3 M$/year. The controllability of the process is proven for ±20% changes of 2-methoxy-2-methyl-heptane production rate.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.ChemE/Product and Process Engineerin
Recent developments in the Massive Modularity Hypothesis: Its analysis and compatibility with the Dual Inheritance Theory
No full textThis paper will focus on and analyze the recent arguments on mental modularity. Although the Massive Modularity Hypothesis (MMH) has been criticized by many philosophers and psychologists, Barrett, Sperber, and Carruthers argue that these criticisms have misunderstood the meaning of the concept of "module" in MMH; they argue that this concept differs from Fodorian module and should be investigated in terms of functional specialization. Through clarifying the concept of module in these arguments and the reasons why MMH based on such mental modules can be supported, the author will consider the relationships between MMH and culture. In particular, the author will argue that MMH can explain social learning because some biases in the Dual Inheritance Theory can be also regarded as modules. It follows that MMH can be compatible with the Dual Inheritance Theory to a significant degree
Manual material handling advice and assistive devices for preventing and treating back pain in workers
No full textBACKGROUND: Training and assistive devices are considered major interventions to prevent back pain among workers exposed to manual material handling (MMH). OBJECTIVES: To determine the effectiveness of MMH advice and training and the provision of assistive devices in preventing and treating back pain. SEARCH STRATEGY: We searched MEDLINE to November 2005, EMBASE to August 2005, and CENTRAL, the Back Group's Trials Register, CINAHL, Nioshtic, CISdoc, Science Citation Index, and PsychLIT to September 2005. SELECTION CRITERIA: We included randomized controlled trials (RCT) and cohort studies with a concurrent control group, aimed at changing human behaviour in MMH and measuring back pain, back pain-related disability or sickness absence. DATA COLLECTION AND ANALYSIS: Two authors independently extracted the data and assessed the methodological quality using the criteria recommended by the Back Review Group for RCTs and MINORS for the cohort studies. One author of an original study supplied additional data for the review.The results and conclusions are based on the primary analysis of RCTs. We conducted a secondary analysis with cohort studies. We compared and contrasted the conclusions from the primary and secondary analyses. MAIN RESULTS: We included six RCTs (17,720 employees) and five cohort studies (772 employees). All studies focused on prevention of back pain. Two RCTs and all cohort studies met the majority of the quality criteria and were labeled high quality.We summarized the strength of the evidence with a qualitative analysis since the lack of data precluded a statistical analysis.There is moderate evidence that MMH advice and training are no more effective at preventing back pain or back pain-related disability than no intervention (four studies) or minor advice (one study). There is limited evidence that MMH advice and training are no more effective than physical exercise or back belt use in preventing back pain (three studies), and that MMH advice plus assistive devices are not more effective than MMH advice alone (one study) or no intervention (one study) in preventing back pain or related disability.The results of the cohort studies were similar to the randomised studies. AUTHORS' CONCLUSIONS: There is limited to moderate evidence that MMH advice and training with or without assistive devices do not prevent back pain, back pain-related disability or reduce sick leave when compared to no intervention or alternative interventions. There is no evidence available for the effectiveness of MMH advice and training or MMH assistive devices for treating back pai
Analysis of Vertical Multiplier on Revised National Institute for Occupational Safety and Health (NIOSH) Lifting Equation for Male Workers in Indonesia Industry
No full textAbstract. Manual Material Handling (MMH) is a risky activity that causes low back pain and has become a worldwide phenomenon, not only in developed countries, but also occur in developing countries. One effort to reduce the injury caused by MMH is the Reccomended Weight Limit (RWL) equation, published by NIOSH. However, NIOSH equation is more tested and researched in European and America. Therefore, it is necessary adjustment for Indonesia people. In this paper, the author analyze the vertical multiplier factor in NIOSH equation for male workers in Indonesia. Multiplier factor is assessed using three criterias. There are biomechanics, physiology, and psychophysical. The result of this study is form of vertical multiplier equation, i.e VM = 1 -0.0310083 (68-V) and VM = 1 -0.00708215 (68-V) for an elevation below the knuckle
Life Support System Design for Habitation in Lunar Lava Tubes
No full textHiroyuki Miyajima, International University of Health and Welfare, JapanICES XXXXThe proceedings for the 2020 International Conference on Environmental Systems were published from July 31, 2020. The technical papers were not presented in person due to the inability to hold the event as scheduled in Lisbon, Portugal because of the COVID-19 global pandemic.In 2009, a large and deep hole, Marius Hills Hole (MMH), was discovered on the Moon with image data acquired by the Selenological and Engineering Explorer (SELENE) lunar probe’s terrain camera. SELENE radar sounder data also indicated a probable presence of lava tubes under the lunar surface in locations close to MMH. Lava tubes can provide shelter for human habitation from harsh environments, such as radiation, micrometeoroid, and the extreme temperatures of the lunar surface. The Japan Society for Aeronautical and Space Sciences (JSASS) Lunar Base Working Group has been tasked with devising a conceptual design for a manned lunar outpost inside the lava tubes reached via MMH. System configurations consisting of life support systems with biomass production systems, in situ resource utilization, and solar or nuclear power plants were designed and evaluated based on their feasibility to support a 100-person colony on the Moon over multiple decades. In accordance with the JSASS Space Exploration Roadmap guidelines, the author of this paper proposed a phased implementation scenario for building a lunar outpost inside lava tubes with the number of people living in it eventually increasing to 100 people with a food self-efficiency rate of 100 % by the 2050s
First in the Nation in Education : Final Report,1984.
No full textThis report is one step in an ongoing process of change and is a plea for commitment for high standards in education in Iowa. Contains the final reports of the six subcommittees as adopted by the Excellence in Education Task Force, and the five recommendations made by the Task Force
A Review and Reconsideration of Non-neoplastic Myometrial Pathology
No full textFrom 1861 to 1962, clinicopathologic research tried to explain the association of abnormal uterine bleeding with uterine enlargement. The etiology was theorized as metropathy, suggesting that myometrial dysfunction may predispose to abnormal uterine bleeding. Research reached a nadir in 1962, when a major review dismissed myometrial hypertrophy as a plausible explanationafter prior rejections of the theories of chronic myometritis, fibrosis uteri, and subinvolution as causes of bleeding. Subsequent to this arose a crusade against unnecessary hysterectomies in the 1970s. Although myometrial hyperplasia (MMH) was proposed in 1868, it is only in the last 25 years that tangible evidence has supported that idea. It now appears that clinically enlarged uteri are due to globoid outward bulging of the uterus, caused by increased intramural pressure; often unrelated to either uterine weight or myometrial thickness. Abnormal (dysfunctional) uterine bleeding may often be due to spontaneous rupture of thrombosed dilated endometrial vessels, due to the combined effects of obstructed venous drainage by increased intramural pressure, and Virchow’s Triad. Despite a century old known association of parity with naturally occurring outer wall myometrial scars (fibrosis uteri with elastosis), it was not previously suggested that these may reflect healing reactions to muscle tears during labor and delivery. We now suggest that smaller, similar inner wall elastotic scars in the nerve rich inner myometrium may explain many cases of pelvic pain. This review suggests that diverse pressure-related lesions may be present in clinically abnormal uteri that have been called “normal” since the crusade against unnecessary hysterectomy.Peer reviewe
Raindrop axis ratios and size distributions in Florida rainshafts: an assessment of multiparameter radar algorithms
No full textEleven penetrations of rainshafts by the University of Wyoming King Air (WKA) aircraft equipped with a two-dimensional (2-D) optical array probe are studied in coordination with multiparameter radar measurements from the National Center for Atmospheric Research (NCAR) CP-2 radar collected in a multicellular storm that occurred on August 8, 1991, of the Convective and Precipitation/Electrification (CaPE) experiment. A comparison is made between the mass-weighted mean diameter (Dm) and rainrate (R) computed from the nine-size spectra and their estimates from multiparameter radar algorithms based on Zdr and Zh. It was found that Dm could be estimated with a mean bias of 0.07 mm and a standard deviation of 0.35 mm. Rainrates (in the range of 10-60 mmh-1) could be estimated from Zh and Zdr with a mean bias of 1-4% and fractional standard error (FSE) of 30-40% depending on the estimator used. Raindrop axis ratios are analyzed as a function of volume equivalent spherical diameter (Deq) in the range 2-6 mm. The mean axis ratio versus the Deq relationship was found to be consistent with previous data from the High Plains (from Colorado and Montana). A study of fluctuations of axis ratio (about their mean value) showed that most drops have axis ratios close to their mean values with oscillation amplitudes to be typically ±10% in axis ratio, again consistent with the earlier High Plains results.This work was supported by the National Science Foundation via Grants ATM-9014600, ATM-9410698, and ATM-9200761
A modality innovation approach: How can royal schiphol group identify and select future proof forms of mobility?
No full textRoyal Schiphol Group is the overarching organisation of multiple airports, among which Amsterdam Schiphol Airport. As the world around these airports is quickly changing with aviation under pressure, and a huge amount of new potential modalities, RSG is in need of an approach to deal with new kinds of modalities. This project was executed for the Innovation Hub, part of the department of Strategy & Airport Planning withing RSG. The initial assignment was to find a way in which RSG could identify and select modalities with potential. During the project, first the context was outlined by analysing the organisation of RSG and the environment in which they are operating. After this literature concerning open innovation has been compared to the way RSG handles external innovations at the moment, as this is how RSG can strengthen their MMH position further. It appeared that currently RSG misses a structured approach to handle new modalities. RSG therefore needs a strategy and a corresponding way to assess innovative modalities. An extra exploration was done, consisting of literature, interviews, observations and internal documents, which led to design principles for the strategy and the toolkit (wat waren deze).In the end a strategy is developed in which 4 steps (identifying, identified, assessing, choosing) were included. In this strategy RSG is encouraged to connect more to the world of mobility and its future with the use of an orchestrator, positioned in-between the innovation hub and a newly acquired scouting team. Executing these steps would lead to a decision on the fifth step: engaging. In the developped strategy, RSG shifts from reacting on modalities to proactively monitoring the world of mobility by providing structure in searching. In this way they can connect to this future world of mobility and by regularly assessing modalities, Schiphol can quickly change direction if necessary. Within the strategy, an orchestrator is present to lead the strategy. The orchestrator will be responsible for setting the exact strategy within the MMH direction, as he or she knows what happens in the market and within Schiphol. He or she will be building bridges between RSG and start-ups.For the assessment, a toolkit is developed in which the factors which influence the potential of a modality at Schiphol have been incorporated as well as the proposed way of working in the strategy. This is reflected in a card deck that should be used to assess modalities, and canvases that should be used to document the session and ensure follow up of the session is assured. Herein, the goal of the toolkit is to facilitate a structured discussion concerning new modalities which can be used to substantiate decision making by RSG. This report describes the entire process gone through to come to the final design. The final design is further elaborated on, an implementation plan is proposed and lastly a discussion and recommendations of the final design are provided, to provide directions in reaching its full potential.Strategic Product Desig
Moving-micro hubs: redefining last-mile logistics with autonomous hub vehicles (AHVs) and delivery robots (ADRs)
No full textThis paper introduces an innovative two-echelon freight distribution system operated by two novel driverless technologies, this in order to improve operation cost, safety and the externalities in comparison to conventional distribution schemes. In the first echelon, Autonomous Hub Vehicles (AHV) aim to mobilize the ADRs from the city peripheries to multiple districts and feed the ADRs with parcels acting as a moving hub. In the second echelon, Autonomous Delivery Robots (ADR) perform the last mile distribution to final costumers in a given district of an urban area. The problem formulation aims to minimize the operational cost of the joint system. The modelling approach of the two-echelon problem consists in continuous approximations, adapting the formulation to the performance and constraints imposed by the novel driverless technologies. The total operating costs of the new system, called Moving Micro Hub (MMH), vary significantly with city demand distribution and the number of delivery zones, with fewer delivery zones and hubs generally leading to lower costs. The ADR operating costs dominate overall expenses and consequently, the optimal ADR capacity and reuse strategies are crucial for minimizing costs. MMH operations can reduce delivery costs by 40–55 % and significant lower global warming potential compared to Business-As-Usual (BaU). However, trade-offs exist between operational cost and occupation of urban space.The participation of the second author in this paper was made under the AMBERES project, PID2020-118641RB-I00, funded by the Spanish Ministry of Science and Innovation, MCIN/AEI/10.13039/501100011033.Peer ReviewedPostprint (published version
