Urchin Foraging and Algal Survival Strategies in Intensely Grazed Communities in Eastern Canada

1990 ◽  
Vol 47 (5) ◽  
pp. 1011-1026 ◽  
Author(s):  
John H. Himmelman ◽  
Henri Nédélec
Keyword(s):  
Dry Matter ◽  
Phenolic Content ◽  
Food Preferences ◽  
Calorific Value ◽  
Dry Mass ◽  
Ash Content ◽  
Survival Strategies ◽  
Eastern Canada ◽  
Intermediate Degree ◽  
Intermediate Rate

We examine relationships between food preferences of the urchin, Strongyhcentrotus droebachiensis, and such properties of fleshy macroalgae as dry mass, ash content, calorific value, and phenolic content. Grazing resistant algae characteristic of urchin dominated habitats rank low in attraction, reflecting the ability of urchins to detect and locate them in the field. They fall into two groups, (1) reds, Phycodrys rubens, Turnerella pennyi, and Ptilota serrata, with a high proportion of dry matter and low phenolic content, and (2) browns, Desmarestia viridis and Agarum cribrosum with low to intermediate calorific values. Algae susceptible to grazing fall into two additional groups, (3) algae with high dry mass which strongly attract urchins and are consumed at an intermediate rate (mostly annuals), and (4) readily eaten perennials which attract urchins to an intermediate degree and have high ash and low phenolic content. The susceptible algae survive through spatial and temporal escapes, mainly in shallow water where the effectiveness of urchin grazing is reduced. The urchin is a selective feeder and its ability to locate preferred algae promotes intake of foods (algae in the subtidal algal fringe and drift algae) that enhance fitness by favouring somatic and gonadal growth.

scholarly journals Dry matter and ash content in leaves and stems of bioenergy crops

2021 ◽  
Author(s):  
I. I. Boiko ◽  
V. O. Hryshchenko ◽  
T. P. Novikova ◽  
O. P. Shevchenko
Keyword(s):  
Dry Matter ◽  
Dry Mass ◽  
Matter Content ◽  
Ash Content ◽  
Energy Crops ◽  
Energy Crop ◽  
Bioenergy Crops ◽  
Dry Matter Content ◽  
Physico Chemical ◽  
One Year

Purpose. Determine the content of dry mass and ash in the leaves and stems of bioenergy crops (miscanthus, switchgrass, willow). Methods. Samples were taken at the end of the growing season (October). The dry matter content was determined by thermogravimetric method, ash content by burning in a muffle furnace. Results. The dry matter content of the leaves varied depending on the year of research and crop. Thus, on average over the years of research, this figure was highest in switchgrass and willow, 65.8–66.0% with an ash content of 4.3–4.5%. The content of dry mass in miscanthus leaves was 9–10% lower compared to other energy crops. The ash content was at the level of 2.8% or 1.5–1.6 times. Physico-chemical parameters of the leaves of energy crops have changed since one year of the study. In miscanthus leaves it varied from 59.9 to 60.2%, switchgrass from 54.5 to 76.9%, and willow from 60.7 to 72.2%. The ash content varied in a smaller range of all energy crops. In the stems of miscanthus, the dry matter content was in the range from 57.5% to 58.9%, in switchgrass it was the largest, from 54.9 to 65.3%, and in the stems of willow from 51.3 to 57.1% over the years of research. The stems of all energy crops had a lower ash content compared to the leaves. Thus, this indicator in miscanthus leaves was at the level of 1.5–1.6%, switchgrass 1.3–2.2%, willow 2.0–2.5% (1.5–3.0 times). Conclusions. The content of dry mass and ash in the leaves and stems varies depending on the type of energy crop. The highest content of dry mass is formed in the leaves of switchgrass (54.5–76.9%) and willow 60.7–72.2%. The ash content is 4.1–4.9% and 4.0–4.5%, respectively. The content of dry mass in miscanthus stems is 57.5–58.9%, switchgrass 54.9–65.3%, willow 51.3–57.1%. The content of ash in the stems of miscanthus is 1.5–1.6%, switchgrass 1.3–2.2, willow 2.0–2.5% or 1.5–3.0 times.

Optimum harvest date of maize for biogas and silage purposes

2009 ◽  
Vol 57 (2) ◽  
pp. 119-125
Author(s):  
G. Hadi
Keyword(s):  
Dry Matter ◽  
Biogas Production ◽  
Weather Conditions ◽  
Vegetation Period ◽  
Dry Mass ◽  
Matter Content ◽  
Harvest Date ◽  
Dry Matter Content ◽  
Dry Matter Yield ◽  
Vegetative Organs

The dry matter and moisture contents of the aboveground vegetative organs and kernels of four maize hybrids were studied in Martonvásár at five harvest dates, with four replications per hybrid. The dry matter yield per hectare of the kernels and other plant organs were investigated in order to obtain data on the optimum date of harvest for the purposes of biogas and silage production.It was found that the dry mass of the aboveground vegetative organs, both individually and in total, did not increase after silking. During the last third of the ripening period, however, a significant reduction in the dry matter content was sometimes observed as a function of the length of the vegetation period. The data suggest that, with the exception of extreme weather conditions or an extremely long vegetation period, the maximum dry matter yield could be expected to range from 22–42%, depending on the vegetation period of the variety. The harvest date should be chosen to give a kernel moisture content of above 35% for biogas production and below 35% for silage production. In this phenophase most varieties mature when the stalks are still green, so it is unlikely that transport costs can be reduced by waiting for the vegetative mass to dry.

Energetic properties of peat saturated with petroleum products

2020 ◽  
Vol 13 (2) ◽  
pp. 105-109
Author(s):  
E. S. Dremicheva
Keyword(s):  
Crude Oil ◽  
Diesel Fuel ◽  
Energy Use ◽  
Experimental Studies ◽  
Calorific Value ◽  
Petroleum Products ◽  
Ash Content ◽  
Motor Oil ◽  
Initial Sample

This paper presents a method of sorption using peat for elimination of emergency spills of crude oil and petroleum products and the possibility of energy use of oil-saturated peat. The results of assessment of the sorbent capacity of peat are presented, with waste motor oil and diesel fuel chosen as petroleum products. Natural peat has been found to possess sorption properties in relation to petroleum products. The sorbent capacity of peat can be observed from the first minutes of contact with motor oil and diesel fuel, and significantly depends on their viscosity. For the evaluation of thermal properties of peat saturated with petroleum products, experimental studies have been conducted on determination of moisture and ash content of as-fired fuel. It is shown that adsorbed oil increases the moisture and ash content of peat in comparison with the initial sample. Therefore, when intended for energy use, peat saturated with petroleum products is to be subjected to additional drying. Simulation of net calorific value has been performed based on the calorific values of peat and petroleum products with different ratios of petroleum product content in peat and for a saturated peat sample. The obtained results are compared with those of experiments conducted in a calorimetric bomb and recalculated for net calorific value. A satisfactory discrepancy is obtained, which amounts to about 12%. Options have been considered providing for combustion of saturated peat as fuel (burnt per se and combined with a solid fuel) and processing it to produce liquid, gaseous and solid fuels. Peat can be used to solve environmental problems of elimination of emergency spills of crude oil and petroleum products and as an additional resource in solving the problem of finding affordable energy.

The impact of elevated atmospheric CO2 and nitrate supply on growth, biomass allocation, nitrogen partitioning and N2 fixation of Acacia melanoxylon

1999 ◽  
Vol 26 (8) ◽  
pp. 737 ◽  
Author(s):  
Marcus Schortemeyer ◽  
Owen K. Atkin ◽  
Nola McFarlane ◽  
John R. Evans
Keyword(s):  
Elevated Co2 ◽  
N2 Fixation ◽  
Dry Matter ◽  
Co2 Concentration ◽  
Dry Mass ◽  
Nitrogen Partitioning ◽  
Atmospheric Co2 ◽  
Acacia Melanoxylon ◽  
Nitrate Supply ◽  
The Impact

The interactive effects of nitrate supply and atmospheric CO2 concentration on growth, N2 fixation, dry matter and nitrogen partitioning in the leguminous tree Acacia melanoxylon R.Br. were studied. Seedlings were grown hydroponically in controlled-environment cabinets for 5 weeks at seven 15N-labelled nitrate levels, ranging from 3 to 6400 mmol m–3. Plants were exposed to ambient (~350 µmol mol–1) or elevated (~700 µmol mol–1) atmospheric CO2 for 6 weeks. Total plant dry mass increased strongly with nitrate supply. The proportion of nitrogen derived from air decreased with increasing nitrate supply. Plants grown under either ambient or elevated CO2 fixed the same amount of nitrogen per unit nodule dry mass (16.6 mmol N per g nodule dry mass) regardless of the nitrogen treatment. CO2 concentration had no effect on the relative contribution of N2 fixation to the nitrogen yield of plants. Plants grown with ≥50 mmol m–3 N and elevated CO2 had approximately twice the dry mass of those grown with ambient CO2 after 42 days. The rates of net CO2 assimilation under growth conditions were higher per unit leaf area for plants grown under elevated CO2. Elevated CO2 also decreased specific foliage area, due to an increase in foliage thickness and density. Dry matter partitioning between plant organs was affected by ontogeny and nitrogen status of the plants, but not by CO2 concentration. In contrast, plants grown under elevated CO2 partitioned more of their nitrogen to roots. This could be attributed to reduced nitrogen concentrations in foliage grown under elevated CO2.

scholarly journals Do minke whales (Balaenoptera acutorostrata) digest wax esters?

1995 ◽  
Vol 74 (5) ◽  
pp. 717-722 ◽  
Author(s):  
Erling S. Nordøy
Keyword(s):  
Energy Density ◽  
Dry Matter ◽  
General Pattern ◽  
Dry Mass ◽  
Wax Esters ◽  
Gut Contents ◽  
Wax Ester ◽  
Balaenoptera Acutorostrata ◽  
Minke Whales

Mammals are known to utilize wax esters with an efficiency of less than 50%. The purpose of the present study was to examine whether or not minke whales (Balaenoptera acutorostrata), which at times may eat considerable amounts of wax-ester-rich krill, represent an exception to this general pattern. Samples of fresh undigested forestomach, as well as colon, contents were obtained from minke whales (n5) that had been feeding on krill (Thysanoessa inermis) for some time. The samples were analysed for dry mass, energy density, lipid content and the major lipid classes, including wax esters. The concentrations of wax esters were compared with previous estimates of dry-matter disappearance of the same type of prey using anin vitrotechnique, to calculate the dry-matter digestibility of wax esters (DMDwax). Wax esters contributed 21% of the energy and 47% of total lipids in the krill diet. The energy density of gut contents decreased by 50% after their passage from forestomach to the end of the colon. The DMDwaxwas 94·1 (SD 2·8)% (n5). This high DMDwaxand the occurrence of fatty alcohols, one of the products of wax-ester hydrolysis, in faeces show that minke whales are very efficient digesters of wax esters and absorb most of the energy-rich products of this process.

scholarly journals Tolerance of Basil Genotypes to Salinity

2017 ◽  
Vol 9 (11) ◽  
pp. 283 ◽  
Author(s):  
Renata V. Menezes ◽  
André D. Azevedo Neto ◽  
Hans R. Gheyi ◽  
Alide M. W. Cova ◽  
Hewsley H. B. Silva
Keyword(s):  
Salinity Tolerance ◽  
Dry Matter ◽  
Membrane Integrity ◽  
Dry Mass ◽  
Ocimum Basilicum ◽  
Medicinal Species ◽  
Relative Water ◽  
Salinity Levels ◽  
Number Of Leaves ◽  
Inorganic Solutes

Basil (Ocimum basilicum L.) is a medicinal species of Lamiaceae family, popularly known for its multiple benefits and high levels of volatile compounds. The species is considered to be one of the most essential oil producing plants. Also cultivated in Brazil as a condiment plant in home gardens. The objective of this study was to evaluate the effect of salinity on the growth of basil in nutrient solution of Furlani and to identify variables related to the salinity tolerance in this species. The first assay was performed with variation of five saline levels (0 - control, 20, 40, 60 and 80 mM NaCl). In the second assay six genotypes were evaluated in two salinity levels 0 and 80 mM NaCl. The height, stem diameter, number of leaves, dry mass and inorganic solutes in different organs, photosynthetic pigments, absolute membrane integrity and relative water content were evaluated. All biometric variables in basil were significantly reduced by salinity. Dry matter yield and percentage of membrane integrity were the variables that best discriminated the characteristics of salinity tolerance among the studied basil genotypes. Basil genotypes showed a differentiated tolerance among the genotypes, the ‘Toscano folha de alface’ being considered as the most tolerant and ‘Gennaro de menta’ as the most sensitive, among the species studied.

scholarly journals Reduction of Ash Content in Raw Coal Using Acids and Alkali

2010 ◽  
Vol 7 (4) ◽  
pp. 1254-1257 ◽  
Author(s):  
K. H. Shivaprasad ◽  
M. M. Nagabhushana ◽  
C. Venkataiah
Keyword(s):  
Sulfuric Acid ◽  
Hydrochloric Acid ◽  
Coal Sample ◽  
Toxic Elements ◽  
Thermal Power ◽  
Calorific Value ◽  
Ash Content ◽  
Subsequent Removal ◽  
Inorganic Matter ◽  
Leaching Experiments

Ash, an inorganic matter present in coal is amenable for dissolution using suitable reagents. Thus the dissolution of ash and its subsequent removal reduces the release of many toxic elements into the environment by coal based industries. Removal of ash also enhances the calorific value. In the present investigation an attempt has been made to reduce the ash content of raw coal obtained from nearest thermal power by using hydrochloric acid, sulfuric acid and sodium hydroxide. A series of leaching experiments were conducted on coal of different size fractions by varying the parameters like concentration, temperature and time of leaching. The results indicate that it is possible to remove nearly 75% of ash from coal sample by leaching.

Potensi Nilai Kalor Biomassa Dari Ampas Tebu (Bagasse) Yang Bersumber Dari Penjual Minuman Sari Tebu Di Kota Pontianak

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Reza Wahyudi ◽  
Muhammad Ivanto ◽  
Murti Juliandari
Keyword(s):  
Laboratory Testing ◽  
Energy Supply ◽  
Alternative Fuels ◽  
Fossil Fuels ◽  
Calorific Value ◽  
Ash Content ◽  
Sugarcane Juice ◽  
Test Results ◽  
Supply Problem ◽  
Direct Data

Dependence on the provision of electricity using fossil fuels is a major energy supply problem in Indonesia. Therefore, it is necessary to provide new and renewable alternative fuels that are effective, efficient, and environmentally friendly. One of the alternative fuels is bagasse biomass. The purpose of this study was to determine the amount of bagasse produced by sellers of sugarcane juice drink in Pontianak City, in order to determine the estimated value of bagasse. The research method used was direct data collection and laboratory testing . Based on the results of the study, the number of vendors of sugarcane juice beverages producing bagasse was 169. Of this amount, produce bagasse that can reach 1,030.9 kg/day. Based on the test results, the estimated moisture content of bagasse was 3.28%, ash content was 0.77%, and carbon remained at 7.65%. So, if converted with the test results of the calorific value of bagasse and made into briquettes bagasse (bio briquettes), which is 19,648 kJ/kg with a density of 0.416 kg/m3, then converted into a potential calorific value of 242,849,280 J/year.

scholarly journals Nitrogen and potassium supply and the morphogenic and productive characteristics of marandu palisadegrass

2010 ◽  
Vol 39 (8) ◽  
pp. 1666-1675 ◽  
Author(s):  
Marcio Mahmoud Megda ◽  
Francisco Antonio Monteiro
Keyword(s):  
Leaf Area ◽  
Dry Matter ◽  
System Development ◽  
Block Design ◽  
Dry Mass ◽  
Dry Matter Production ◽  
Root System Development ◽  
Randomized Block Design ◽  
Matter Production ◽  
Specific Length

The objective of this work was to study morphogenic characteristics, and dry matter production of roots and shoots of marandu palisadegrass (Brachiaria brizantha cv. Marandu) submitted to combinations of nitrogen and potassium, in a nutritive solution, employing silica as substrate. The experiment was carried out in a greenhouse during the summer. It was used a 5² fractionated factorial scheme with 13 combinations of nitrogen and potassium, which were distributed in a randomized block design, with four replications. The nitrogen × potassium interaction was significant for the number of tillers and leaves, for leaf area, for shoots and root section dry mass, for total length and surface and specific length and surface in the roots. Production of aerial part dry mass positively correlated with the number of tillers and leaves and grass leaf area. Nitrogen rates modulated the root system development, and the root specific length and surface decreased when high rates of nitrogen and potassium were supllied. Nitrogen and potassium influence Marandu palisadegrass morphogenic characteristics, which are determinant for grass dry matter production.

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