Synthesis and characterization of hazelnut oil-based biodiesel     

Y.X. Xu  M.A. Hanna 《Industrial Crops and Products》2009,29(2-3):473-479

The demand for diesel fuel far exceeds the current and future biodiesel production capabilities of the vegetable oil and animal fat industries. New oilseed crops that do not compete with traditional food crop are needed to meet existing energy demands. Hybrid hazelnut oil is just such an attractive raw material for production of biodiesel. Hazelnut oil was extracted from hybrid hazelnuts and the crude oil was refined. Hazelnut oil-based biodiesel was prepared via the transesterification of the refined hazelnut oil with excess methanol using an alkaline catalyst. The effects of reaction temperature, time and catalyst concentration on the yield of diesel were examined, and selected physical and chemical properties of the biodiesel were evaluated. The biodiesel yield increased with increasing temperature from 25 to 65 °C and with increasing catalyst concentration from 0.1 to 0.7 wt%. The increase in yield with reaction time was nonlinear and characterized by an initial faster rate, followed by a slow rate. Hazelnut oil-based biodiesel had an average viscosity of 8.82 cP at 25 °C, which was slightly higher than that of the commercial soy-based diesel (7.92 cP at 25 °C). An approximate 12 °C higher onset oxidative temperature and a 10 °C lower cloud point of hazelnut oil biodiesel than those of its commercial soy counterpart indicated a better oxidative stability and flowability at low temperature. The average heat of combustion of hazelnut oil biodiesel was 40.23 kJ/g, and accounted for approximately 88% of energy content of diesel fuel. The fatty acid composition of hazelnut oil-based biodiesel was the same as the nature oil.  相似文献   

A theoretical explanation of the priming effect based on microbial growth with two limiting substrates     

Hanna Parnas 《Soil biology & biochemistry》1976,8(2):139-144

A theoretical and experimental analysis of the effects of substrate ratio on microbial growth is presented. The effects of change in the ratio of two substrates (C and N) is given as an example for the theoretical model. Average growth rate (population biomass at time t, divided by t), as opposed to steady-state growth rate, is introduced as a better measure of growth rate in a changing environment. The main results of the theoretical model and the experimental example are: (a) microbial population yield at the stationary phase is maximal when the initial ratio between the substrates, equals the stoichiometric ratio (the required ratio for growth); (b) the time in which the population is growing until it reaches the stationary phase, is also maximal when the initial ratio equals the stoichiometric ratio; (c) the average growth rate as a function of the initial. C/N ratio approaches a curve with one maximum point which is when the initial ratio equals the stoichiometric ratio. The results of the dependence of the average growth rate on the C/N ratio of the substrate are used to explain the “priming effect”.  相似文献   

Changes in cellular structures and enzymatic activities during browning of Scots pine callus derived from mature buds     

Laukkanen H  Rautiainen L  Taulavuori E  Hohtola A 《Tree physiology》2000,20(7):467-475

Visible browning is a typical feature of callus cultures derived from shoot tips of mature Scots pine (Pinus sylvestris L.). Because the ability of callus to regenerate is low, we determined the effect of browning on growth and changes in cellular structure during culture. Striking alterations in cellular structure were detected by LM (light microscopy), EM (electron microscopy) and SEM (scanning electron microscopy). Accumulation of phenolic substances was shown by histochemical staining. Staining for beta-glucosidase activity of soluble proteins that had been subjected to polyacrylamide gel electrophoresis indicated lignification of cells. The measured growth rate of callus was low compared with a hypothetical growth curve. Peroxidase activity increased rapidly soon after the start of the culture period, but especially between the second and third weeks of culture. At this time, the degradation of cell membranes and browning began coincident with the loss of chlorophyll. We conclude that browning is associated with cell disorganization and eventual cell death, making tissue culture of mature pine especially difficult.  相似文献   

Seasonal variations in location and population structure of endophytes in buds of Scots pine     

Pirttilä AM  Pospiech H  Laukkanen H  Myllylä R  Hohtola A 《Tree physiology》2005,25(3):289-297

We studied the location and distribution of a bacterial isolate, a Mycobacterium sp., in buds of Scots pine (Pinus sylvestris L.). Using a probe specific for the 16S rRNA of the Mycobacterium sp., the bacterium was found by in situ hybridization in the meristematic tissues of 40% of all bud samples examined. Because we had previously found other bacterial and fungal endophytes in the meristematic tissues of Scots pine buds, we studied their occurrence in buds during shoot development and dormancy. Using probes targeted to the 16S or 18S rRNA of the endophytes Mycobacterium sp., Methylobacterium spp., Pseudomonas spp. and Rhodotorula minuta, endophytes were found in association with growing tissues, with Methylobacterium spp. being the dominant species. Endophytes were detected in abundance before elongation or differentiation of a bud, but once a tissue was fully developed, endophytes were no longer detected. Metabolic activity of the endophytes was suppressed at the onset of, and during, dormancy of Scots pine, but recovered before the following growing season.  相似文献   

Das Käferkreuz bei Klosterneuburg     

Erwin Schimitschek  Hanna Schönwälder 《Journal of pest science》1956,29(6):90-91

Ohne Zusammenfassung  相似文献   

Comment on "Disentangling the drivers of β diversity along latitudinal and elevational gradients"     

Tuomisto H  Ruokolainen K 《Science (New York, N.Y.)》2012,335(6076):1573; author reply 1573

Kraft et al. (Report, 23 September 2011, p. 1755) analyzed two data sets and concluded that "there is no need to invoke differences in the mechanisms of community assembly in temperate versus tropical systems to explain these global-scale patterns of β diversity." We show that their conclusion is based on inappropriate data and inadequate methods of analysis.  相似文献   

Nutrition and Behavior of Fennec Foxes (Vulpes zerda)     

Janet L. Dempsey  Sherilyn J. Hanna  Cheryl S. Asa  Karen L. Bauman 《Veterinary Clinics of North America: Exotic Animal Practice》2009,12(2):299-312

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Short- and long-term control of Vespula pensylvanica in Hawaii by fipronil baiting     

Hanna C  Foote D  Kremen C 《Pest management science》2012,68(7):1026-1033

BACKGROUND: The invasive western yellowjacket wasp, Vespula pensylvanica (Saussure), has significantly impacted the ecological integrity and human welfare of Hawaii. The goals of the present study were (1) to evaluate the immediate and long‐term efficacy of a 0.1% fipronil chicken bait on V. pensylvanica populations in Hawaii Volcanoes National Park, (2) to quantify gains in efficacy using the attractant heptyl butyrate in the bait stations and (3) to measure the benefits of this approach for minimizing non‐target impacts to other arthropods. RESULTS: The 0.1% fipronil chicken bait reduced the abundance of V. pensylvanica by 95 ± 1.2% during the 3 months following treatment and maintained a population reduction of 60.9 ± 3.1% a year after treatment in the fipronil‐treated sites when compared with chicken‐only sites. The addition of heptyl butyrate to the bait stations significantly increased V. pensylvanica forager visitation and bait take and significantly reduced the non‐target impacts of fipronil baiting. CONCLUSION: In this study, 0.1% fipronil chicken bait with the addition of heptyl butyrate was found to be an extremely effective large‐scale management strategy and provided the first evidence of a wasp suppression program impacting Vepsula populations a year after treatment. Copyright © 2011 Society of Chemical Industry  相似文献   

Effect of anesthesia duration on the quality of recovery in horses undergoing elective and emergency surgeries using the same anesthetic protocol     

Hanna Vermedal  Alexander Valverde  William Sears 《Canadian journal of veterinary research》2021,85(3):193

The objective of this study was to investigate the effect of anesthesia duration on the quality of recovery in horses. The medical records of horses that were anesthetized and underwent surgery for elective and emergency soft tissue and orthopedic conditions from 2013 to 2019 were reviewed. Horses included in the study (N = 305) fulfilled the following requirements: all had the same premedication/induction protocol and the same balanced anesthesia for maintenance and were anesthetized by the same, experienced Board-certified anesthesiologist. A standardized anesthetic recovery score was completed for all horses to evaluate their recovery and the following interactions were assessed: age, body weight, breed, sex, American Society of Anesthesiologists status, type of surgical procedure, occurrence of hypotension, use of dobutamine, number of additional doses of xylazine/ketamine after isoflurane discontinuation, anesthesia duration, post-anesthetic sedation, and end-tidal isoflurane concentration during maintenance and at the time of transfer to the recovery room. These interactions were assessed based on the quality of recovery score using logistic regression. Duration of anesthesia (P = 0.021) and age (P = 0.003) negatively affected the quality of recovery. The odds of a worse recovery score were increased by 1.20-fold (1.03, 1.41; lower and upper limits) for every additional 30 min of anesthesia duration, while the odds of a worse recovery score were increased by 1.09-fold (1.03, 1.16) for every additional 1 y of age. In conclusion, the results of this retrospective study indicate that increasing the anesthesia duration negatively affects the quality of recovery in horses undergoing routine and emergency surgical procedures.  相似文献   

Active site inhibitors of acetolactate synthase     

Lynn M. Abell  Wayne S. Hanna  Keith J. Kunitsky  James A. Kerschen 《Pest management science》1995,44(1):89-92

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