Sulphuric Acid Water Research Articles

GERMINATION AND EARLY GROWTH PERFORMANCE OF PREKESE, TETRAPLEURA TETRAPTERA TO SEED PRETREATMENT METHODS AND PHOSPHORUS FERTILIZER IN THE NURSERY PHASE

Seeds of Tetrapleura tetraptera trees have poor germination due to their hard and impervious seed coat. This research was conducted to determine the possibilities of reducing seed dormancy using seed pretreatment via the application of sulphuric acid and hot water and then phosphorus for better seedling growth. Seeds pretreated with sulphuric acid had a significantly (P˂0.05) increased germination rate (by 60%) compared to seeds pretreated with hot water (40%). The application of phosphorus fertilizer stimulated the early growth of the species. This research provides information for practical use.

Hydrochemical Characteristics of Hot Springs in the Intersection of the Red River Fault Zone and the Xiaojiang Fault Zone, Southwest Tibet Plateau

The coupling relationship between regional seismic activity and the hydrogeochemical field provides an important theoretical basis for regional earthquake precursor exploration. The intersection area of the Red River fault zone (RRF) and the Xiaojiang fault zone (XJF) in southeast Yunnan province has become the focus area of earthquake monitoring and prediction because of its special tectonic position in China. There were 20 hot springs that were sampled and analyzed in the laboratory for major elements, including trace elements, silica, stable isotopes (δ18O and δD), and strontium isotopes, from the years 2015 to 2019. (1) The meteoric water is the main source of recharge for thermal springs in the study area, and recharged elevations ranged from 1.1 to 2 km; (2) the geothermometer method was used to estimate the region of thermal storage temperature, and its temperature ranged between 64.3 to 162.7 °C, whereas the circulation depth ranged from 1.1 to 7.2 km. Hydrochemical types were mainly controlled by aquifer lithology, in which sodium bicarbonate and sulphuric acid water gathered mainly in the RRF, while calcium bicarbonate water gathered mainly in the XJF. According to the silicon–enthalpy equation method, the temperature range and cold water mixing ratio were 97–268 °C and 61–97%, respectively; (3) the circulation depth of the RRF was deeper than that of the XJF, and it was mainly concentrated in the second segment and the fourth segment on the RRF. Most of the hot spring water was immature with a weak water–rock reaction; (4) the hot water intersections of RRF and XJF were obviously controlled by the fault and the cutting depth of granite; (5) the relationship discussed between geothermal anomaly and earthquake activity had a good correspondence with regional seismicity. The intensity of the reaction between underground hot water and the surrounding rock may lead to the change of pore pressure, and the weakening effect of groundwater on fracture may change accordingly, followed by the change in the adjustment of tectonic stress. Eventually, the difference in seismic activity was shown, implying that deep fluid has an important control action on the regional seismicity.

Durability and water absorption behaviour of rubberised concrete incorporating burnt clay brick powder

Rubberised concrete has suffered from reduced durability and water absorption performance compared to conventional concrete and its decreased durability is limiting its practical use. To reduce the inferior durability and water absorption performance of rubberised concrete, the inclusion of Burnt Clay Brick Powder (BCBP) partially replacing cement is considered. This paper captures the water absorption properties of rubberised concrete containing BCBP. Durability properties of rubberised concrete incorporating BCBP exposed to sea water and sulphuric acid were also evaluated in comparison with conventional concrete. Specimens were totally submerged in sulphuric acid and sea water in order to investigate the 90-days durability behaviour. These specimens were assessed in relation to strength, mass and diameter losses. Water absorption investigations illustrated that incorporating 5% BCBP in concrete enhanced water absorption performance compared to control concrete. The outcomes of durability tests showed that concrete mixes with 5% BCBP experienced the most excellent behaviour for both exposures. Moreover, the use of BCBP in rubberised concrete seemed to have protected rubberised concrete from experiencing substantial strength, diameter and mass losses. Eventually, the use of BCBP was suggested as a significant criterion that could achieve improved durability and water absorption properties of rubberised concrete.

Durability of fibre-reinforced cementitious composites (FRCC) including recycled synthetic fibres and rubber aggregates

We discuss mechanical performance of fibre-reinforced cementitious composites under exposure to four aggressive environments, namely alkaline, saline, sulphuric acid and distilled water immersion. A standard commercial Portland cement based matrix is considered alongside its lightweight modification wherein quarzitic sand is partially replaced by recycled rubber crumbs. Also, virgin polypropylene fibres are contrasted to PP+PET blended fibres where the PET fraction is obtained from recycling food packaging waste. Performance is assessed in bending as well as in compression. We find that recycled based specimens perform surprisingly well and that exposure to the aggressive environments mainly affects the matrix and it is not necessarily more detrimental to the lightweight partially recycled phase. A one-way analysis of variance (ANOVA) confirms the statistical significance of the results, which fully support the idea that the adoption of a substantial recycled fraction in construction materials still allows for high performance and durability standards.

Evaluation of pretreatment potential and hydrogen recovery from lignocellulosic biomass in an anoxic double-staged bioelectrochemical system

The possible impact of bio and electrochemical reactions during pretreatment of rice straw using solvents, sulphuric acid (SA), ammonia (AM), sodium hydroxide (NA), and distilled water (W) was investigated. The total volatile fatty acids (tVFAs) of 163.48 ± 10.49 mM in the electrochemical pre-treatment in the presence of sodium hydroxide (ENA) followed by sulfate-reducing bacteria (EBA) (140.88 ± 0.07 mM) indicating the involvement of electrolytic breakdown of lignocellulosic biomass. The hydrogen production of 0.224 ± 0.05 and 0.218 ± 0.10 mM/g of the substrate was found in the ENA and anoxic sodium hydroxide pre-treatment (CNA) respectively. There was no detectable gasification in SA and AM electrochemical pre-treatments. The major advantage of the electrochemical process is the formation of acetic acid at a lower temperature, whereas processes like autohydrolysis form it at high temperatures during stream explosion pretreatment. The hydrogen production of 1.26 mM/g was found from anoxic hydrolysate pretreated (ECP) rice straw. The SEM and FTIR analysis show distortion of outer layers of biomass in the electrochemical pretreatment (ECP) system, which improved its accessibility towards enzymes for value-added product recovery.

The analysis of tensile strength and elasticity in slag concrete with curing variations at 90 days age

Cement is a concrete constituent material that has a great influence on concrete quality, both normal and high-quality concrete. High quality concrete in SNI 03-6468-2000 is defined as concrete which has compressive strength characteristics above 41.4 MPa. During the process, cement produces gas emissions obtained from combustion, calcination of limestone, and the use of electrical energy. The purpose of using cement in the preparation of concrete itself is as a binder between aggregates. Nowadays, commonly used cement (OPC cement) can be replaced with slag cement. Slag cement is the result of the addition of Granulated Blast Furnace Slag into the final grinding of cement which is a waste product from the steel ore smelting process. This research is comparing the magnitude of the tensile strength and the modulus of elasticity of the samples with 100% OPC cement and those with 100% slag cement. The samples used were cylinders with 15 cm diameter and 30 cm height. The tests were carried out when the concrete reaches 90 days age. The curing of the samples was carried out with four variations which is by submerging those in tap water, Kuala Tanjung sea water, Sulphuric Acid water, and compound curing. The results of this test were obtained if the slag cement-used concrete is able to have a tensile strength that is almost the same as OPC cement-used concrete which is 4.341 MPa for normal concrete and 4.293 MPa for slag concrete and its modulus of elasticity of 46103.67 MPa for normal concrete and 46892.82 MPa for slag concrete.

Effect of Three Pregermination Treatments on the Growth of Emerging Seedlings of Acacia auriculiformis (Cunn. Ex. Benth)

This research was carried out to determine the effect of some pregermination treatments on the seeds of Acacia auriculiformis as it affects growth. The treatments involve the effect of sulphuric acid (concentration and time), mechanical scarification (at different sides), and hot water treatment (volume and time). Split plot design was used for acid treatment and hot water treatment, while Randomized Complete Block Design (RCBD) was used for mechanical scarification. The experiment was carried out at Federal University of Agriculture, Abeokuta, Nigeria. Parameters assessed include; plant height, stem height, leaf number. Acid treatment was carried out using different concentration of sulphuric acid (98%, 50% and 20%) and different treatment time (2 minutes, 5 minutes and 10 minutes). Concentration of acid was significant (p<0.05) on plant height, stem height and leaf number, higher concentration of acid (98%) enhanced morphological parameters of Acacia auriculiformis. Result showed that mechanical scarification significantly affect stem height (p<0.05), however, while mechanical scarification does not significantly affect plant height, the highest mean plant height (8.98 cm) was observed in seeds that were mechanically scarified at the micropyle; early germination of seeds was also noticed. Hot water treatment was carried out using different volume of water (50 cl and 1 litre) and varying treatment time (2 minutes, 4 minutes, 6 minutes and 10 minutes), the treatment showed no significant difference, and this method is not favourable for breaking seed dormancy of Acacia auriculiformis. Result showed that 100% germination could be achieved within seven (7) days when seeds are mechanically scarified at the micropyle, circumference, distal-end and micropyle+distalend, provided the seeds are viable. This research conclude that, acid scarification using H2SO4 at 98% concentration is the best method yielding better morphological parameters in Acacia auriculiformis, followed by mechanical scarification (especially when scarified at the micropyle).

Morphological and physiological characterization of seed heteromorphism in Medicago denticulata Willd.

Under natural conditions, Medicago denticulata produces heteromorphic seeds differing in seed coat colour—cream and brownish black. The present study was conducted in order to determine morphological and physiological differences among heteromorphic seeds of M. denticulata in relation to dormancy and germination behaviour. Brownish black seeds with high moisture content were non-dormant and germinated to a high percentage. However, cream seeds with low moisture content were dormant and exhibited lesser germination without dormancy breaking treatments. Scanning electron microscope studies revealed papillose surface pattern in both seeds. However, brownish black seeds differed from cream seeds by having small cracks scattered all over the surface. Various dormancy breaking treatments viz., sandpaper scarification, soaking in sulphuric acid and hot water significantly increased the germination of cream seeds indicating seed coat imposed dormancy in these seeds. Accelerated ageing of brownish black seeds for 20 or more days resulted in complete inhibition of germination. Whereas, some cream seeds (~ 13%) aged for 20 days were still able to germinate. With accelerated ageing, both seeds recorded decrease in starch and total soluble proteins with concomitant increase in membrane leakage, total soluble sugars and free amino acids. Persistence studies under field conditions revealed that cream seeds present on soil surface or at a burial depth of 2 and 10 cm were able to germinate up to 12 months; but no germination was observed in brownish black seeds buried for 12 or more months. Results of accelerated ageing studies and field persistence suggest longer persistence for cream seeds as compared to brownish black seeds.

Dormancy Breaking and the Influence of Gibberellic Acid on the Early Growth of Tamarindus indica Seedlings in Mubi, Nigeria

The purpose of this research was to determine the appropriate methods of breaking seed dormancy, level of water uptake, and the influence of gibberellic acid on the early growth of Tamarindus indica seedlings. The scarification methods used included: concentrated sulphuric acid (H2SO4), manual scarification, flaming, hot and cold water treatments. The experiments were conducted in the laboratory on Petri dishes and in potting media. GA3 was used to optimize the production of seedlings by spraying the solution on the foliage. The treatment for 10 minutes with concentrated H2SO4 gave the maximum germination percentage and water uptake (80.41%). GA3 enhances the growth of the seedlings by increasing the height, the number of leaves and stem girth at eight weeks after sowing. In conclusion, all the scarification treatments applied to the seeds of T. indica proved effective. The ten minutes treatment with concentrated H2SO4 was the best treatment for breaking seed dormancy of T. indica. And gibberellic acid enhanced early and fast seedling growth as it increase height, number of leaves and stem girth of T. indica.

Effects of waste glass and rubber on the SCC: rheological, mechanical, and durability properties

One of the practical ways for recycling solid wastes is by using them as a part of natural aggregates in concrete. The major purpose of this study is to investigate the effects of waste materials, such as glass and rubber particles as a partial substitution of coarse and fine aggregates on the rheological, mechanical and durability properties of self compacting concrete (SCC). On this note, seventeen mixtures have been designed by replacing glass and rubber in proportions of 5, 10, 15 and 20%. To assess the rheological and mechanical characteristics, fresh (J-ring, L-box, slump-flow, T50cm, and V-funnel) and hardened (compressive and flexural strengths and ultrasonic pulse velocity) tests were performed. Furthermore, in order to determine the durability against acid corrosion, the water absorption and sulphuric acid attack tests were performed. The test results showed that, the use of glass particles in the SCC can slightly enhance the workability; however, it has no remarkable impact on the mechanical properties. On the other hand, adding waste rubber to the SCC in addition to decrease of workability reduces compressive and flexural strengths and ultrasonic pulse velocity. Durability results showed that both glass and rubber can significantly improve SCC resistance against sulphuric acid attack.

Effect of Pre-Sowing Treatments on Seed Germination and Seedling Growth of Silver Butterfly Tree (Bauhinia rufescens)

Three experiments were conducted in a plastic greenhouse at the Sinna Garden of the Crop Science Department of the University of Ghana, Legon, Accra to investigate into pre-sowing treatment (water treatment, growth regulator, and sulphuric acid scarification and water soaking) effects on seed germination and seedling growth of Bauhinia rufescens from October to December, 2011 and January to April, 2012, respectively. The experimental design used was complete randomized design. There were 4 treatments in experiment 1, 7 in experiment 2 and 6 in experiment 3. Each experiment was replicated five (5) times. The results showed that Bauhinia rufescens seeds soaked in hot water at 65 0 C for 60 minutes gave the highest mean germination rate, tallest plant height and highest number of leaves per plant at 49 days after soaking. It also had the widest stem diameter, highest fresh shoot and root weight, highest fresh root and dry root weight and number of roots per seedling. Seeds soaked in 500 ppm Gibberelic acid(GA3) produced the highest number of leaves per plant and tallest plants at 49 DAS. Seeds soaked in 750 ppm GA3 had the highest number of leaves per plant at 49 DAS and highest fresh shoot weight. Seeds soaked in 1000 ppm Promalin differed significantly from 500 ppm GA3 and the control in germination percentage. Seeds soaked in 1000 ppm Promalin differed significantly from 500 ppm GA3 and the control in germination percentage. Acid scarified seeds for 60 minutes plus soaking in tap water for 24 hours differed significantly from the seeds treated withother growth regulator rates plus 24 hours soaking in germination percentage. Acid scarified seeds for 45 minutes plus soaking in tap water for 24 hours had the tallest plant and highest number of leaves per plant at 49 DAS, widest stem diameter, highest fresh shoot and root weight and dry shoot weight. Soaking seeds in hot water at 65 0 C for 60 minutes and/or in acid (H2SO4) for 45 minutes plus soaking in tap water for 24 hours is recommended as pre-sowing treatment for Bauhinia rufescens for maximum mean germination rate and vigorous vegetative growth of seedlings.

A 3D particle Monte Carlo approach to studying nucleation

The nucleation of sulphuric acid molecules plays a key role in the formation of aerosols. We here present a three dimensional particle Monte Carlo model to study the growth of sulphuric acid clusters as well as its dependence on the ambient temperature and the initial particle density. We initiate a swarm of sulphuric acid–water clusters with a size of 0.329 nm with densities between 107 and 108 cm−3 at temperatures between 200 and 300 K and a relative humidity of 50%. After every time step, we update the position of particles as a function of size-dependent diffusion coefficients. If two particles encounter, we merge them and add their volumes and masses. Inversely, we check after every time step whether a polymer evaporates liberating a molecule. We present the spatial distribution as well as the size distribution calculated from individual clusters. We also calculate the nucleation rate of clusters with a radius of 0.85 nm as a function of time, initial particle density and temperature. The nucleation rates obtained from the presented model agree well with experimentally obtained values and those of a numerical model which serves as a benchmark of our code. In contrast to previous nucleation models, we here present for the first time a code capable of tracing individual particles and thus of capturing the physics related to the discrete nature of particles.

PECULIARITIES S OF THE INFLUENCE OF CHEMICAL AND PHYSICO-CHEMICAL BONDING OF MOISTURE WITH WOOD ON THE KINETICS OF DRYING PROCESS

The authors have considered some issues of influence of chemical and physical-chemical bonding of moisture with wood on the processes of moistening and drying of wood. We have found that the most complex physical and chemical phenomena occur in wood when changing its initial moisture content, and the subsequent saturation of the capillaries of wood walls with water leads to the formation of bound moisture. Wood has a complex chemical composition and structure, and water has a specific structure. In the process of interaction, the properties of both components change: the wood substance passes from the glassy to the colloidal state, and the water from the free state to bound state. In addition, the laws of capillary phenomena, hydrostatics and hydrodynamics cannot be applied to the bound moisture in colloidal materials because it is in adsorption with wood. The process of binding moisture (fluid) to a colloidal body at the first stage is similar to mixing of two fluids of different molecular weights. During the absorption of liquid by a colloidal body, a certain amount of heat (heat of swelling) is released, similarly to the heat release when dissolving alcohol or sulphuric acid in water. Using the law of conservation of energy and mass, one can establish the relationship of mean integral values of moisture content and temperature with the intensity of heat-and-mass transfer, and, accordingly, with the rate of drying in the form of a heat balance. According to the law of energy conservation, the amount of heat that is supplied to the body is equal to the amount of heat that goes to the evaporation of moisture plus the heat going to heat the body itself. Removal of the bonded moisture occurs during the deceleration of drying. The intensity of drying and the intensity of heat transfer continuously decrease over time. The change in the intensity of drying occurs in a complicated fashion, which is determined by the form of moisture bonding with the material and by the mechanism of movement of heat and moisture within the material. Thus, the main solution of kinetics is derived – the rate of the process of drying bound moisture, which can be applied to any wood material and any method of drying. The resolution of the issue of the influence of the forms of moisture bonding with wood on the technological processes depends on two aspects: the complexity of chemical structure of the wood material and the complex unique properties of water in the wood.

EFFECT OF PRE-SOWING TREATMENTS ON SEED GERMINATION OF P. eurycarpa AND P. khinjuk – KURDISTAN REGION

In the new global economic botany, seed germination ecology has become a central issue for increasing the number of the edible plants both in natural forest, cultivated field and nurseries. In this context, there has recently been an increasing amount of literature on the important economical value of Pistachio tree species for human livelihood activities and developments. In Kurdistan Region as a part of Zagrosian area and from ethnobotanical standpoint, Pistachio tree species are considered as an important natural resource of income to rural Kurdish people. Nevertheless, the farmers are often confronted to the difficulties of the seed germination of Pistachio tree species and the debate continues about the best pre-treatment for improving their propagation. Therefore, the main objective of this research is to analyze the effect of pre-sowing treatments on seed germination of two wild Pistachio tree species (Pistacia eurycarpa and Pistacia khinjuk) in Kurdistan Region. These pre-sowing treatments include hot water (for 5, 10 and 15 minutes), sulphuric acid scarification (for 5, 10 and 15 minutes), water soaking (for 1, 2 and 3 days), fruit (seed with exocarp) and untreated seeds (control). The results showed that the best seed germination (35%) was obtained from soaking in chemical scarification for 10 minutes for both pistachio species. While low germination rate (1%) achieved from fruits with exocarp for P. khinjuk with only 1%. On the other hand, the best seed germination for P. eurocarpa was obtained from soaking seeds in H2SO4 for 5 and 10 minutes (as 36%, 42% respectively). Meantime low germination rate was achieved from soaking seed in water for 2 and 3 days as 8% and 6% respectively. This research has been done to provide an alternative method for increasing the cultivation of (Pistacia eurycarpa and Pistacia khinjuk) seed germination in Kurdistan Region. Therefore, this study will serve as a base for future studies and investigations in issue of economic botany and improvement of the rural Kurdish livelihood activities.

Controllable Phase Transformation in Extracting Valuable Metals from Chinese Low-Grade Nickel Sulphide Ore

In this work, a two-stage sulphuric acid roasting and water leaching system was chosen to extract valuable metals from Chinese low-grade nickel sulphide ore. By optimizing the two-stage roasting process, first roasting temperature at 295°C with particle size of 80–91 μm with an acid-ore ratio of 1.1:1 for 2 h, and second roasting temperature at 620°C for 2 h, it was found that more than 98% of the nickel and 99% of the copper but less than 14.38% of Fe were leached into the water. Attempts were made via x-ray diffraction analysis, scanning electron microscopy, chemical phase analysis, and differential thermal and thermogravimetric analysis to reveal the phase transformations for Ni, Cu, and Mg, which could be expressed as mineral phases → sulphates hydrate → sulphates and for iron as mineral phases → hydrated ferrous sulphate → ferric sulphates and ferric oxide → oxide. The results of this work suggest that a controllable phase transformation by using a two-stage sulphuric acid roasting process is a feasible method for efficiently extracting valuable metals from Chinese nickel sulphide ore.

Comparison of the SAWNUC model with CLOUD measurements of sulphuric acid-water nucleation.

Binary nucleation of sulphuric acid‐water particles is expected to be an important process in the free troposphere at low temperatures. SAWNUC (Sulphuric Acid Water Nucleation) is a model of binary nucleation that is based on laboratory measurements of the binding energies of sulphuric acid and water in charged and neutral clusters. Predictions of SAWNUC are compared for the first time comprehensively with experimental binary nucleation data from the CLOUD chamber at European Organization for Nuclear Research. The experimental measurements span a temperature range of 208–292 K, sulphuric acid concentrations from 1·106 to 1·109 cm−3, and distinguish between ion‐induced and neutral nucleation. Good agreement, within a factor of 5, is found between the experimental and modeled formation rates for ion‐induced nucleation at 278 K and below and for neutral nucleation at 208 and 223 K. Differences at warm temperatures are attributed to ammonia contamination which was indicated by the presence of ammonia‐sulphuric acid clusters, detected by an Atmospheric Pressure Interface Time of Flight (APi‐TOF) mass spectrometer. APi‐TOF measurements of the sulphuric acid ion cluster distributions ( (H2SO4)i·HSO4− with i = 0, 1, ..., 10) show qualitative agreement with the SAWNUC ion cluster distributions. Remaining differences between the measured and modeled distributions are most likely due to fragmentation in the APi‐TOF. The CLOUD results are in good agreement with previously measured cluster binding energies and show the SAWNUC model to be a good representation of ion‐induced and neutral binary nucleation of sulphuric acid‐water clusters in the middle and upper troposphere.

Control of silica polymerisation during ferromanganese slag sulphuric acid digestion and water leaching

A major obstacle to the hydrometallurgical treatment of ferromanganese slags is the way in which silica polymerisation is controlled during sulphuric acid digestion and water leaching. In an acidic medium, silica enters in solution and forms silicic acid, which polymerises into silica gel and makes solid-liquid separation difficult.This article will show that the quick leach model, also called the water-starved system, limits silica solubilisation and its subsequent polymerisation during manganese extraction from ferromanganese slags by rejecting most of the ferromanganese slag silica content in the leach residue. It will further illustrate that the silica content in the residue is dependent on the acid concentration used during acid digestion. It will also show that dissolved silica in the pregnant leach solution is high when an unrestricted quantity of water is used and low when the water quantity is restricted during water leaching. Furthermore, a method for silica gel recovery from ferromanganese slag will be presented, as well as the silica gel analysis, in order to confirm the theory presented in this article.Manganese extraction of up to 90% is obtained and the leach residue presents good latent hydraulic properties, which can be used as an addition to Portland cement or a gypsum replacement. More than 95% of the initial silica content of the slag is rejected in the leach residue, and a residue silica content of more than 27% is obtained. Thus, silica solubilisation and polymerisation are controlled and solid-liquid separation is accelerated.

Response of Concrete Made WITH Partially Treated Textile Effluent TO Acid Attack AND Chloride Attack

This paper presents the utilization of partially treated textile effluent as mixing water in OPC and fly ash concrete. The effluent was collected at two stages of treatment viz. anaerobic treatment (AE) and tertiary treatment (TTE). The basic effluent properties were obtained by standard methods. The chemical resistance to hydrochloric acid, sulphuric acid and sea water attack were studied. The weight loss and strength loss of concrete specimens after immersion were noticed for 3 months in regular interval. The anaerobic treated effluent is found to be producing good resistance to aggressive environments when compared with potable water and tertiary treated effluent. The fly ash samples showed better resistance in all the three environments.

Prediction of intramuscular fat content and major fatty acid groups of lamb M. longissimus lumborum using Raman spectroscopy

A hand held Raman spectroscopic device was used to predict intramuscular fat (IMF) levels and the major fatty acid (FA) groups of fresh intact ovine M. longissimus lumborum (LL). IMF levels were determined using the Soxhlet method, while FA analysis was conducted using a rapid (KOH in water, methanol and sulphuric acid in water) extraction procedure. IMF levels and FA values were regressed against Raman spectra using partial least squares regression and against each other using linear regression. The results indicate that there is potential to predict PUFA (R2=0.93) and MUFA (R2=0.54) as well as SFA values that had been adjusted for IMF content (R2=0.54). However, this potential was significantly reduced when correlations between predicted and observed values were determined by cross validation (R2cv=0.21–0.00). Overall, the prediction of major FA groups using Raman spectra was more precise (relative reductions in error of 0.3–40.8%) compared to the null models.

Influence of mother plant and scarification agents on seed germination rate and vigor in Retama sphaerocarpa L. (Boissier)

Abstract: The aim of this study was to optimize nursery production of Retama sphaerocarpa, an important shrub species in some plant communities of arid and semi-arid zones, which is used in the restoration of degraded areas. This Fabaceae family species has seed coat dormancy, which may hinder germination. In order to assess the influence of scarification agents and mother plant effect on germination rate and seedling vigour, a germination test with fresh seed was performed in a germination chamber, following a factorial design with two fixed factors (mother plant effect and scarification agent). The test took place in the forest nursery of the Institute of Agricultural Sciences, Lisbon, Portugal. The fresh seeds were subjected to scarification by two agents, sulphuric acid (96% concentration) and hot water (80°C), the former for 60 minutes and the latter for 30 seconds, plus an untreated control. The scarification of seeds using sulphuric acid was found to be the best method to enhance germination of this species (p 79%) and the best vigour index. Differences between mother plants were also statistically significant and could influence germination success. We suggest that effectiveness of hot water scarification may be improved by additional time of seed immersion. The technical viability for seed production of this species was confirmed and key factors for its success identified. Owing to its potential for use on land rehabilitation, increment on plant commercial demand should be expected in the near future.