Month of harvest and yield components of tea tree. II. Oil concentration, composition, and yield

1996 ◽  
Vol 47 (5) ◽  
pp. 817 ◽  
Author(s):  
GJ Murtagh ◽  
GR Smith
Keyword(s):  
Biomass Yield ◽  
Significant Loss ◽  
Oil Yield ◽  
Energy Reserves ◽  
Tea Tree ◽  
Air Temperatures ◽  
Oil Concentration ◽  
Biomass Yields ◽  
The Mean ◽  
High Concentrations

Changes in the concentration, composition, and yield of oil in coppice growth of tea tree (Melaleuca alternzfolia) were assessed when plants were harvested in different months. Oil concentrations in leaves were lower when plants were harvested in July-September than in other months, but biomass yields were higher. Consequently, there was no consistent effect of harvest month on oil yield. Oil yield varied as much between the same month in different years, as between months within a year. The oil concentration in one harvest was positively related to the biomass yield at the previous harvest of the same plants, suggesting that a carryover of energy reserves contributed to oil production. The oil concentration was also positively related to the mean air temperatures over the 3 months before harvest. The proportion of the economically significant compounds in oil, terpinen-4-01 and 1,8-cineole, was not affected by either the month of harvest or regrowth cycle, but other compounds did change. There was a significant loss of monoterpene olefins from oil which was present at high concentrations.

Variation in oil concentration and economic return from tea-tree (Melaleuca alternifolia Cheel) oil

1990 ◽  
Vol 30 (5) ◽  
pp. 675 ◽  
Author(s):  
GJ Murtagh ◽  
RJ Etherington
Keyword(s):  
Dry Weight ◽  
Production Costs ◽  
Melaleuca Alternifolia ◽  
Tea Tree ◽  
Percentage Points ◽  
Average Production ◽  
Oil Concentration ◽  
The Mean ◽  
Set Up ◽  
Returns On Investment

The oil concentration in tea-tree (Melaleuca alternifolia Cheel) twigs was measured over 8 consecutive days during November 1987, and over 10 out of 12 consecutive days in January 1989. The oil concentration, measured in units of volume of oil per unit dry weight of twigs (v/DW), varied markedly between successive days, from 2.9-1.8% v/DW (a 38% decrease) to 1.8-3.4% v/DW (a 89% increase). The reason for such variation is unknown but it had a pronounced effect on the profitability of growing the crop. The profit, which was expressed as a return on the total set-up cost of $A17 2591ha, was estimated for each of the measured oil concentrations and fixed values of biomass yield, the price of oil and average production costs. The extreme daily variations in oil concentration mentioned above caused the return on investment to decline by 11 percentage points and increase by 16 points, respectively. When measured at the same site, the mean oil concentration increased from 3.1% vPW in November 1987 to 5.8% v/DW in January 1989. As a consequence, the respective mean returns on investment increased from 0 to 26%.

Weed interference reduces yield of coppiced tea tree (Melaleuca alternifolia)

2000 ◽  
Vol 40 (8) ◽  
pp. 1157
Author(s):  
J. G. Virtue ◽  
B. G. Sutton ◽  
G. J. Murtagh ◽  
R. D. Cousens
Keyword(s):  
Field Experiments ◽  
Yield Loss ◽  
Biomass Yield ◽  
Leaf Biomass ◽  
Yield Losses ◽  
Melaleuca Alternifolia ◽  
Tea Tree ◽  
Weed Interference ◽  
Leaf Oil ◽  
Oil Concentration

The effects of weeds on the oil yield of tea tree, Melaleuca alternifolia (Maiden and Betche) Cheel, were examined in 6 field experiments. Tea tree is grown in plantations as a coppice crop, being annually harvested for its leaf oil. Plots were maintained with and without weed control between successive harvests. Weed interference significantly reduced leaf biomass yield of regrowth tea tree in 5 of 6 experiments, with a mean yield loss of 25%. Yield losses ranged from 9 to 47%, and these were correlated with weed biomass remaining at harvest. Weed interference did not significantly affect leaf oil concentration, or its chemical composition.

Studies of the oestrous cycle, oestrus and pregnancy in the koala (Phascolarctos cinereus)

Reproduction ◽  
2000 ◽  
pp. 49-57 ◽  
Author(s):  
SD Johnston ◽  
MR McGowan ◽  
P O'Callaghan ◽  
R Cox ◽  
V Nicolson
Keyword(s):  
Luteal Phase ◽  
Post Partum ◽  
Plasma Concentrations ◽  
External Genitalia ◽  
Oestrous Cycle ◽  
Phascolarctos Cinereus ◽  
Pregnant Females ◽  
Peripheral Plasma ◽  
The Mean ◽  
High Concentrations

As an integral part of the development of an artificial insemination programme in the captive koala, female reproductive physiology and behaviour were studied. The oestrous cycle in non-mated and mated koalas was characterized by means of behavioural oestrus, morphology of external genitalia and changes in the peripheral plasma concentrations of oestradiol and progestogen. The mean (+/- SEM) duration of the non-mated oestrous cycle and duration of oestrus in 12 koalas was 32.9 +/- 1.1 (n = 22) and 10.3 +/- 0.9 (n = 24) days, respectively. Although the commencement of oestrous behaviour was associated with increasing or high concentrations of oestradiol, there were no consistent changes in the morphology or appearance of the clitoris, pericloacal region, pouch or mammary teats that could be used to characterize the non-mated cycle. As progestogen concentrations remained at basal values throughout the interoestrous period, non-mated cycles were considered non-luteal and presumed anovulatory. After mating of the 12 koalas, six females gave birth with a mean (+/- SEM) gestation of 34.8 +/- 0.3 days, whereas the remaining six non-parturient females returned to oestrus 49.5 +/- 1. 0 days later. After mating, oestrous behaviour ceased and the progestogen profile showed a significant increase in both pregnant and non-parturient females, indicating that a luteal phase had been induced by the physical act of mating. Progestogen concentrations throughout the luteal phase of the pregnant females were significantly higher than those of non-parturient females. Parturition was associated with a decreasing concentration of progestogen, which was increased above that of basal concentrations until 7 days post partum.

N, P and K Fertilizers Alter Plant Growth, Essential Oil Yield and Gender of Sweet Gale (Myrica gale L)

2014 ◽  
Vol 8 (1) ◽  
pp. 9-17
Author(s):  
X. Chang ◽  
P. Martin
Keyword(s):  
Plant Growth ◽  
Field Trials ◽  
Oil Yield ◽  
Oil Composition ◽  
Myrica Gale ◽  
The North ◽  
Oil Concentration ◽  
N Treatment ◽  
And Gender ◽  
Essential Oil Yield

To investigate whether the fertilizers N, P or K individually affect plant growth, oil content and the gender of sweet gale, two trials, pot and field trials, were carried out at Orkney College UHI in Scotland. A pot trial was established with eight soils which were collected from different sweet gale trial sites in the north of Scotland. Although neither shoot yield nor oil concentration in shoots was affected by soil, there were significant differences in shoot yields as a result of fertilizer treatments (nitrogen (N), phosphorus (P), potassium (K) or none (control)). The best yield was obtained from the N treatment which was double to that of the control and P treatments. N, P or K fertilizers did not consistently affect shoot oil concentration in two seasons; however, oil yield was significantly affected, and N treatment produced two-three fold oil yield increases compared with the control or P treatment. In the N treatment, the increase in shoot yield was positively correlated with total nitrogen or nitrate nitrogen in the soil, suggesting the occurrence of a nitrogen priming effect. Data suggested that as shoot yield increased the oil concentration in shoots decreased. Neither soil nor N, P or K fertilizers had a significant effect on oil composition. Amongst fertilizer treatments, P resulted in the largest number of plants changing gender from female to male. A field N trial confirmed that nitrogen significantly enhanced the shoot yield of young plants.

scholarly journals Optimization of cultivation conditions for Microcystis aeruginosa for biodiesel production using response surface methodology

2020 ◽  
Vol 44 (1) ◽  
Author(s):  
Samar A. El-Mekkawi ◽  
N. N. El-Ibiari ◽  
Ola A. El-Ardy ◽  
Nabil M. Abdelmonem ◽  
Ahmed H. Elahwany ◽  
...  
Keyword(s):  
Response Surface ◽  
Microcystis Aeruginosa ◽  
Biomass Yield ◽  
Bubble Column ◽  
Biodiesel Production ◽  
Cultivation Conditions ◽  
Inoculum Concentration ◽  
Initial Inoculum ◽  
High Lipid ◽  
Oil Concentration

Abstract Background Biodiesel is expected to play a key role in the development of a sustainable, economical, and environmentally safe source of energy. The third generation of biodiesel is derived from microalgae and cyanobacteria that have sufficient amount of oil. The optimization of biomass and oil content in biodiesel production based on algal cultivation relies upon several factors. The present experimental work aims at optimizing some of the cultivation conditions to obtain maximum oil and biomass yield and create a prediction model that describe the effect of the initial inoculum concentration, and irradiance on the biomass yield and oil concentration were designed using Design Expert 6.0.8. Results The results revealed that the optimum surface-to-volume ratio for the airlift bubble column photobioreactor was 0.9, and the most applicable model for describing Microcystis aeruginosa growth was the hyperbolic tangent model with a model constant value of 1.294 mg·L− 1·d− 1/μmol·m− 2·s− 1. The optimum cultivation conditions were 81 μmol·m− 2·s− 1 irradiance and 67 mg·L− 1 initial inoculum concentration, and these conditions achieved a biomass yield of 163 mg·L− 1·d− 1 and an oil concentration of 143 mg·L− 1. Conclusions This work focused on the cultivation of microalgae in closed systems. Cyanobacteria as M. aeruginosa has high lipid content, and high lipid productivity makes it suitable as a lipid feed stock for biodiesel production. The response surface method was the most suitable route to study the simultaneous influence of irradiance and initial inoculum concentration through statistical methods as well as to establish a model for predicting the biomass yield and oil concentration of M. aeruginosa.

The effects of metabolic inhibitors on the contraction of creatine-depleted muscle

1982 ◽  
Vol 60 (2) ◽  
pp. 114-119 ◽  
Author(s):  
G. W. Mainwood ◽  
M. Alward ◽  
B. Eiselt
Keyword(s):  
Creatine Phosphate ◽  
Diaphragm Muscle ◽  
Metabolic Inhibitors ◽  
Energetic Cost ◽  
Energy Reserves ◽  
Similar Extent ◽  
Additional Energy ◽  
Energy Stores ◽  
Wet Weight ◽  
The Mean

Rats were fed on a diet containing 1% β-guanidinopropionate (Gp) to deplete their muscles of creatine. The apparent energy reserves (creatine phosphate (CrP) + ATP) of rested state diaphragm muscle strips were found to be 79% depleted by this treatment. To determine if the effective energy reserves for contraction were depleted to a similar extent, the response to direct electrical stimulation (0.2-s tetani) was measured in the presence of inhibitors of respiration (NaCN) and glycolysis (iodoacetate). Only 4 ± 1 contractions could be elicited from strips from Gp-fed animals. Normal strips gave 15 ± 2 contractions under the same conditions. For both sets of diaphragms the energetic cost of contraction in terms of ~P was approximately 1 μmol/g wet weight. The mean level of Pi generated following stimulation to exhaustion was 10.1 μmol/g more in normal than in depleted strips. It is concluded that no significant additional energy stores such as phosphorylated Gp are readily available for contraction in muscles depleted of creatine by Gp treatment.

scholarly journals Automatic Detection of Missing Access Points in Indoor Positioning System †

Sensors ◽  
2018 ◽  
Vol 18 (11) ◽  
pp. 3595 ◽  
Author(s):  
Rafał Górak ◽  
Marcin Luckner
Keyword(s):  
Automatic Detection ◽  
Significant Loss ◽  
Classification Error ◽  
Positioning System ◽  
Random Forest Algorithm ◽  
Access Points ◽  
The Mean ◽  
Academic Building ◽  
Indoor Positioning System ◽  
Indoor Localisation

The paper presents a Wi-Fi-based indoor localisation system. It consists of two main parts, the localisation model and an Access Points (APs) detection module. The system uses a received signal strength (RSS) gathered by multiple mobile terminals to detect which AP should be included in the localisation model and whether the model needs to be updated (rebuilt). The rebuilding of the localisation model prevents the localisation system from a significant loss of accuracy. The proposed automatic detection of missing APs has a universal character and it can be applied to any Wi-Fi localisation model which was created using the fingerprinting method. The paper considers the localisation model based on the Random Forest algorithm. The system was tested on data collected inside a multi-floor academic building. The proposed implementation reduced the mean horizontal error by 5.5 m and the classification error for the floor’s prediction by 0.26 in case of a serious malfunction of a Wi-Fi infrastructure. Several simulations were performed, taking into account different occupancy scenarios as well as different numbers of missing APs. The simulations proved that the system correctly detects missing and present APs in the Wi-Fi infrastructure.

scholarly journals Palaeoclimates: the first two billion years

2006 ◽  
Vol 361 (1470) ◽  
pp. 917-929 ◽  
Author(s):  
James F Kasting ◽  
Shuhei Ono
Keyword(s):  
South Africa ◽  
Oxygen Isotopes ◽  
Natural Explanation ◽  
Witwatersrand Basin ◽  
Late Archaean ◽  
Bacterial Sulphate Reduction ◽  
Climatic Constraints ◽  
The Mean ◽  
High Concentrations ◽  
Earth’S Climate

Earth's climate during the Archaean remains highly uncertain, as the relevant geologic evidence is sparse and occasionally contradictory. Oxygen isotopes in cherts suggest that between 3.5 and 3.2 Gyr ago (Ga) the Archaean climate was hot (55–85 °C); however, the fact that these cherts have experienced only a modest amount of weathering suggests that the climate was temperate, as today. The presence of diamictites in the Pongola Supergroup and the Witwatersrand Basin of South Africa suggests that by 2.9 Ga the climate was glacial. The Late Archaean was relatively warm; then glaciation (possibly of global extent) reappeared in the Early Palaeoproterozoic, around 2.3–2.4 Ga. Fitting these climatic constraints with a model requires high concentrations of atmospheric CO 2 or CH 4 , or both. Solar luminosity was 20–25% lower than today, so elevated greenhouse gas concentrations were needed just to keep the mean surface temperature above freezing. A rise in O 2 at approximately 2.4 Ga, and a concomitant decrease in CH 4 , provides a natural explanation for the Palaeoproterozoic glaciations. The Mid-Archaean glaciations may have been caused by a drawdown in H 2 and CH 4 caused by the origin of bacterial sulphate reduction. More work is needed to test this latter hypothesis.

scholarly journals Direct Calculation of Thermodynamic Wet-Bulb Temperature as a Function of Pressure and Elevation

2013 ◽  
Vol 30 (8) ◽  
pp. 1757-1765 ◽  
Author(s):  
Sayed-Hossein Sadeghi ◽  
Troy R. Peters ◽  
Douglas R. Cobos ◽  
Henry W. Loescher ◽  
Colin S. Campbell
Keyword(s):  
Air Temperature ◽  
Mean Absolute Error ◽  
Direct Calculation ◽  
Ambient Air ◽  
Absolute Error ◽  
Mean Square ◽  
Air Temperatures ◽  
Order Polynomial ◽  
The Mean ◽  
Very High

Abstract A simple analytical method was developed for directly calculating the thermodynamic wet-bulb temperature from air temperature and the vapor pressure (or relative humidity) at elevations up to 4500 m above MSL was developed. This methodology was based on the fact that the wet-bulb temperature can be closely approximated by a second-order polynomial in both the positive and negative ranges in ambient air temperature. The method in this study builds upon this understanding and provides results for the negative range of air temperatures (−17° to 0°C), so that the maximum observed error in this area is equal to or smaller than −0.17°C. For temperatures ≥0°C, wet-bulb temperature accuracy was ±0.65°C, and larger errors corresponded to very high temperatures (Ta ≥ 39°C) and/or very high or low relative humidities (5% < RH < 10% or RH > 98%). The mean absolute error and the root-mean-square error were 0.15° and 0.2°C, respectively.

scholarly journals The isotopic record at an alpine glacier and its implications for local climatic changes and isotopic homogenization processes

2001 ◽  
Vol 47 (156) ◽  
pp. 147-151 ◽  
Author(s):  
He Yuanqing ◽  
Wilfred H. Theakstone ◽  
Yao Tandong ◽  
Shi Yafeng
Keyword(s):  
Equilibrium Line Altitude ◽  
Temperature Variations ◽  
Alpine Glacier ◽  
Temperature Changes ◽  
Natural Factors ◽  
Air Temperatures ◽  
Regional Temperature ◽  
The Mean ◽  
A Site ◽  
The Relationship

AbstractStratigraphic variations of oxygen isotopes in the snow which accumulates during the winter at the Norwegian glacier Austre Okstindbreen are not entirely eliminated after 1–2 months of ablation in the following summer. The relationship between regional temperature changes and δ18O values in the snowpack is affected by many natural factors, but 1989/90 winter air temperatures were reflected in the snow which remained on Austre Okstindbreen at 1350 m a.s.l. in July 1990. There were many variations of δ18O values in the 4.1m of snow above the 1989 summer surface, but variations in the underlying firn were relatively small. Meltwater percolation modifies the initial variations of δ18O values in the snowpack. At a site below the mean equilibrium-line altitude on Austre Okstindbreen, increased isotopic homogenization within a 10 day period in July accompanied an increase of the mean δ18O value. Although the isotopic record at a temperate glacier is likely to be influenced by more factors than is that at polar glaciers, it can provide an estimate of the approximate trend of local temperature variations.

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