2,923 research outputs found
Hypergolic stream impingement phenomena nitrogen tetroxide/hydrazine
Mechanism and design parameter effects in stream mixing and separation of nitrogen tetroxide-hydrazine impingemen
Computer modeling of rocket engine ignition transients Final report
Computer modeling of rocket engine ignition transient
Combustion instability prediction using a nonlinear bipropellant vaporization model
Combustion instability prediction using nonlinear bipropellant vaporization mode
Transients influencing rocket engine ignition and popping Interim report
Engine design and operating parameters studied for effects on rocket engine ignition and poppin
Impacts of a Novel Non-Stimulant-Based Ergogenic Supplement Blend on Maximal Oxygen Uptake and Time to Fatigue: A Pilot Study
CrossFit athletes are frequently subjected to high-intensity training sessions that demand commensurately robust muscular and cardiovascular endurance capacities. Despite the propensity of research investigating the role of aerobically-associated ergogenic aids, few have elucidated their combination in highly trained athletic populations. PURPOSE: to evaluate the preliminary efficacy of a novel supplement comprising several empirically-supported ingredients and their potential ability to impact the aerobic performance in experienced CrossFit athletes. METHODS: Six experienced CrossFit athletes (3M/3F; aged 41±13y; training 5±1 times/week) ingested 2.0mL daily of a novel supplement proprietary formulation (Flow, Cerus, Vero Bleach, FL) containing Beetroot (Beta Vulgaris), Ashwagandha (Withania Somnifera), Arjuna (Terminalia Arjuna), Rhodiola (Rhodiola Rosea), as well as Cayenne (Capsicum Annuum) for 28 days between a baseline and post-supplementation maximal oxygen consumption (VO2MAX) assessment. Participants were asked not to change their exercise habits and consumed the aforementioned supplement 30 minutes prior to each training session and/or during the morning on rest days. A 4.0mL supplement dose was additionally administered 30 minutes prior to the post-supplementation aerobic capacity assessment. Both the treadmill VO2MAX and test time-to-fatigue (elapsed finish-start time) were analyzed using separate paired-samples t-tests at a significance level of pRESULTS: Although VO2MAX did not significantly increase (p=.146; Hedge’s G=.737), the participants’ treadmill assessment TTE demonstrated a statistically significant improvement (p=.012, Hedge’s G=.726) from pre- to post-supplementation (10.67 to 12.11 minutes [13.55%], respectively). Notably, the 2/6 participants that experienced pre- to post-supplementation VO2MAX decrements tested positive for COVID-19 during their supplementation period. CONCLUSION: The present pilot study showcases the potential of a novel aerobically-associated ergogenic supplement. Nevertheless, future research should more rigorously evaluate these data by employing a randomized, double-blinded, and placebo-controlled design, as well as a larger sample size before any definitive conclusions may be inferred
The use of a cephalonium containing dry cow therapy and an internal teat sealant, both alone and in combination
AbstractThe dry period is a critical time in the lactation cycle, being the optimum time to cure existing intramammary infection (IMI) as well as encompassing the periods of highest susceptibility to new infection. Currently, IMI in the dry period is controlled with antibiotic dry cow therapy. The aim of this randomized control trial was to investigate different dry cow therapy regimens by stratifying cows by likely infection status at drying off in herds with low somatic cell count (SCC; bulk milk SCC <250,000 cells/mL) in southwest England. All quarters in 890 cows were recruited. The recruited cows were categorized as either infected or uninfected on the basis of SCC and clinical mastitis history. Ipsilateral quarters within each cow were randomly allocated to receive 1 of 4 different treatment regimens according to their infection category. Quarters in high-SCC infected cows were allocated to receive antibiotic dry cow therapy either alone or in combination with an internal teat sealant; quarters in low-SCC uninfected cows were allocated to receive teat sealant either alone or in combination with antibiotic dry cow therapy. All quarters were sampled for bacteriology at drying off and again within 10 d post-calving. Quarters were subsequently monitored for clinical mastitis for the first 100 d of lactation. The mass of residual sealant was assessed immediately post-calving to allow assessment of the association of sealant retention with treatment efficacy. Models were constructed to assess the efficacy of the different regimens in preventing IMI. Apparent cure rates of existing IMI with major pathogens were consistently >90% in quarters receiving antibiotic. Combination treatment of high-SCC infected cows resulted in an increased likelihood of being pathogen free post-calving (odds ratio=1.40; 95% credibility interval=1.03–1.90). The benefits of combination treatment of low-SCC uninfected cows were less clear. With respect to clinical mastitis, combination treatment of high-SCC infected cows resulted in a decreased likelihood of developing clinical mastitis in the first 100 d of the subsequent lactation (odds ratio=0.68; 95% credibility interval=0.48–0.98). The retention of the internal sealant was adversely affected by its use in combination with antibiotic dry cow therapy
Combustion instability response with asymmetric pressure disturbances
Combustion stability in rocket engines affected by pressure disturbance
-Algebras, the BV Formalism, and Classical Fields
We summarise some of our recent works on -algebras and quasi-groups
with regard to higher principal bundles and their applications in twistor
theory and gauge theory. In particular, after a lightning review of
-algebras, we discuss their Maurer-Cartan theory and explain that any
classical field theory admitting an action can be reformulated in this context
with the help of the Batalin-Vilkovisky formalism. As examples, we explore
higher Chern-Simons theory and Yang-Mills theory. We also explain how these
ideas can be combined with those of twistor theory to formulate maximally
superconformal gauge theories in four and six dimensions by means of
-quasi-isomorphisms, and we propose a twistor space action.Comment: 19 pages, Contribution to Proceedings of LMS/EPSRC Durham Symposium
Higher Structures in M-Theory, August 201
Degradation of polymer banknotes through handling, and effect on fingermark visualisation
The surface structure of mint (as-issued) and handled polymer five pounds sterling banknotes was studied by atomic force microscopy and laser scanning confocal microscopy. A total of 1856 fingermarks on mint and handled banknotes from four different issuing banks (Bank of England, Bank of Scotland, Royal Bank of Scotland and Clydesdale Bank) were visualised with Vacuum Metal Deposition (VMD), Cyanoacrylate Fuming (CAF) and, on Clydesdale Bank notes, magnetic fluorescent powder. VMD was significantly more effective in developing fingermarks on handled banknotes, across all the banks studied, although effectiveness varied with issuing bank. For example, on handled Bank of England notes 45% of marks showed ridge detail with VMD development and 28% with CAF; for Bank of Scotland handled notes success rates were 17% with VMD and 1% with CAF. Microscopy of degraded banknotes showed the loss of intaglio printing and the formation of a cracked surface structure in the handled notes. These features can lead to the trapping of powder, or contaminants, increasing quantity of development agent in fingermark background between the ridges, decreasing contrast and decreasing performance of powder-based fingermark development techniques. These same features can restrict the migration of components of the fingermark, preventing fingermarks degrading through spread of material and thus reducing potential formation of empty prints, so that VMD development is not adversely affected
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