Lime Layer Research Articles

Characterization of Compounds Formed and Added on Surface of Outdoor Seville City Hall

The study of the stone surface was helpful before the restoration of the Sevilla City Hall façade. This study supplied information of the environmental factors affecting the stone and the restoration treatments used in previous interventions. The stone was thin grained carbonate constituted essentially by fragments of bioclasts and fine sand. The stone was covered by an acrylic resin. Black crust was found. Gypsum and mortars has been added to cover losses of pieces or to fix fragments of stones. A layer of lime on the surface was also detected.

Monitoring controlled graves representing common burial scenarios with ground penetrating radar

Implementing controlled geophysical research is imperative to understand the variables affecting detection of clandestine graves during real-life forensic searches. This study focused on monitoring two empty control graves (shallow and deep) and six burials containing a small pig carcass (Sus scrofa) representing different burial forensic scenarios: a shallow buried naked carcass, a deep buried naked carcass, a deep buried carcass covered by a layer of rocks, a deep buried carcass covered by a layer of lime, a deep buried carcass wrapped in an impermeable tarpaulin and a deep buried carcass wrapped in a cotton blanket. Multi-frequency, ground penetrating radar (GPR) data were collected monthly over a 12-month monitoring period. The research site was a cleared field within a wooded area in a humid subtropical environment, and the soil consisted of a Spodosol, a common soil type in Florida. This study compared 2D GPR reflection profiles and horizontal time slices obtained with both 250 and 500 MHz dominant frequency antennae to determine the utility of both antennae for grave detection in this environment over time. Overall, a combination of both antennae frequencies provided optimal detection of the targets. Better images were noted for deep graves, compared to shallow graves. The 250 MHz antenna provided better images for detecting deep graves, as less non-target anomalies were produced with lower radar frequencies. The 250 MHz antenna also provided better images detecting the disturbed ground. Conversely, the 500 MHz antenna provided better images when detecting the shallow pig grave. The graves that contained a pig carcass with associated grave items provided the best results, particularly the carcass covered with rocks and the carcass wrapped in a tarpaulin. Finally, during periods of increased soil moisture levels, there was increased detection of graves that was most likely related to conductive decompositional fluid from the carcasses.

Alternative control ofAethina tumidaMurray (Coleoptera: Nitidulidae) with lime and diatomaceous earth

Aiming at alternative small hive beetle control, slaked lime, powdered limestone and diatomaceous earth (Fossil Shield® FS 95, FS 90.0 and FS 90.0s) were evaluated for their effects on pupation and adult emergence in the laboratory. Limestone, FS 90.0 and FS 95 showed no significant effect. Slaked lime in autoclaved soil prevented pupation, but was lethal only in high dosages of 10 and 15 g per 100 g soil. In non-autoclaved soil, low slaked lime dosages of 0.5 and 5 g resulted each in >90% mortality, possibly due to enhanced pathogen activity. However, with FS 90s (also using non-autoclaved soil) it’s the reverse. Larvae penetrated a slaked lime layer and pupated in untreated soil below. Slaked lime and FS 90.0s were also tested in traps (diagnostic trays) in the laboratory and in honeybee field colonies. In the field, 30.5 ± 29.3% of the adults were caught in the traps with slaked lime. FS 90.0s caused 100% adult mortality in field traps, where 57.9 ± 8.3% of the hives’ adult SHB infestation died within 48 h. Our data showed a good potential for the use of FS 90.0s as inhive treatment and suggest further research with slaked lime as alternative control of SHB.

Reaction rate coefficients in decomposition of lumpy limestone of different origin

A method is described to evaluate the reaction rate coefficients, pore diffusivity and thermal conductivity of the lime layer in the decomposition of limestone by linearization of conversion curves, based on the shrinking core model. Spherical and long cylindrical samples with diameters in the range of 20–50 mm were prepared and thermally decomposed in a chamber furnace at constant temperature and CO 2 pressure. By weighing and simultaneous measuring of the internal temperature, the decomposition behavior of these samples was studied. The reaction rate coefficients thus obtained vary from 0.003 to 0.012 m s −1 with a factor of 4, depending upon the origin of the limestone. The reaction coefficients measured by other authors based on limestone powder lie within this range.

English

Appalachian coal processing wastes are typically acid forming with potential acidities in Virginia ranging from an average of 12 Mg CCE demand/1000 Mg waste up to > 50 Mg/1000 Mg where higher sulfur coal seams are cleaned. Direct seeding of these materials is further complicated by high rock fragment content, low water-holding capacity, and high summer surface soil temperatures. In Virginia, conventional revegetation protocols established by the Virginia Division of Mined Land Reclamation (DMLR) in the early 1980's required the return of 1.2 m of soil cover over all actively permitted coal wastes. Unfortunately, most active piles at the time had no available topsoil reserves, so the only alternative was to disturb adjacent properties via blasting to generate spoil derived topsoil substitutes. Between 1982 and 1990, we investigated a number of direct seeding and reduced topsoil cover alternatives in an effort to determine the optimal combination of soil amendments and cover soil thickness for the successful revegetation of varying coal waste acidity conditions. The centerpiece of this research effort was a series of topsoil wedge experiments established over three different coal waste materials where cover soil depth was varied from 0 to 125 cm, with and without lime (15 to 25 Mg/ha) at the soil/coal waste contact. Multi-year vegetation and soil sampling results indicated that a minimum of 45 to 75 cm of cover soil was required over highly acid-forming refuse (47 Mg CCE demand/1000 Mg), with the shallower depth sufficient when a lime layer was applied at the contact zone. Over moderately acid-forming materials (15 to 35 Mg CCE /1000 Mg), as little as 25 cm of cover soil was adequate as long as lime was added to the soil/waste contact zone. Coal waste materials that are < 15 Mg CCE/1000 Mg net acid forming can be direct seeded if high P applications are coupled with heavy mulch or organic amendments, especially when the fill faces are not south-facing. These results were implemented into permit review and oversight by Virginia DMLR in the early 1990's and over the past 15 years, a wide range of active coal waste piles have been successfully revegetated with soil covers of 50 cm or less.

Backscattered electron imaging of the steel–concrete interface

Backscattered electron images were obtained under low vacuum conditions on polished sections of the steel–concrete interface to examine whether the formation of any of the hydration products of cement is favoured at this location. It was observed that the hydration products at the steel are typical of those in the bulk of the cement paste. In particular, there was no general indication of preferential formation of calcium hydroxide at the steel. This provides further support for the suggestion that the early hypothesis concerning the formation of a lime layer at the steel, which inhibits corrosion initiation, should be extended to include the effects of all solids with pH dependent dissolution characteristics. These include both the inhibitive effects of other solid phases that resist a local fall in pH and the aggressive nature of ions like chloride that may be released by a local pH reduction.

Efficacy of amitraz (Taktic ® 12.5% EC) as a dip for the control of Boophilus microplus (Canestrini) (Acari: Ixodidae) on cattle

Four groups of cattle infested with Boophilus microplus (Canestrini) were each dipped in a different concentration of amitraz diluted from a 12.5% EC formulation to determine the efficacy and performance of the product in an 11 400 l dipping vat. Except for the period when heifers were dipped, animals were restrained in stanchions placed individually inside 3.3×3.3 m 2 stalls within an open-sided barn. The amitraz in the vat was stabilized with hydrated lime to maintain a pH of ca. 12. Analyses of vat samples showed that concentrations of amitraz in the vat were 7.6 to 13% lower than the targeted concentrations of 0.010, 0.015, 0.020, and 0.025% active ingredient (AI) for dilutions prepared according to instructions on the manufacturer's label. The large quantity of hydrated lime added to the vat (10 kg/1000 l) interfered with the HPLC analysis of vat samples. Therapeutic efficacy of each of the four observed concentrations (0.0088, 0.0131, 0.0174, and 0.0231% AI) of amitraz was excellent (>99% control). However, the rapid detachment of all ticks from an animal within a few hours after treatment with amitraz, that has been frequently observed, was not pronounced in the present study. Only 47% of the B. microplus detached in the first 4 h post-treatment, and 84% detached within the first 24 h. All of the treatments, except the lowest concentration, provided protection of cattle against re-infestation by B. microplus larvae for 14 days post-treatment. Possibly as a result of the formation of a compact layer of lime and amitraz on the bottom after the vat was undisturbed for six weeks, intense agitation was required to re-suspend the active ingredient.

Cement-lime mortars joining porous stones of masonries able to stop the capillary rise of water

The capillary rise of water in porous stones of masonries can be stopped by interleaving appropriate cement-lime mortars between the building stones. The type of cement in the mortar influences the time requested for the formation of an impermeable lime layer, responsible of the phenomena.

Thermal decomposition of limestone in a large scale thermogravimetric analyzer

The decomposition of calcium carbonate spheres has been investigated using limestone particles of sizes 7, 5 and 2 mm in a large scale thermogravimetric analyzer under near isothermal conditions. Experiments were conducted in atmospheres of pure N 2, and 7%, 14% and 21% CO 2-N mixtures. Data are interpreted in terms of apparent activation energy E and frequency factor A assuming a first-order reaction and Arrhenius temperature dependence of the rate constant. Microscopic analysis has shown that the decomposition reaction takes place at the boundary between the undecomposed carbonate and the layer of porous lime formed outside. This boundary moves towards the center of the particle but remains spherical in shape.

Bioactivity in limed soil of a spruce forest

The stimulative effect of lime on the bioactivity of various soil horizons was demonstrated by the ATP test, and respiration and microcalorimetric measurements, but not by FDA hydrolysis or the iron reduction test. The latter showed clear inhibition. When the natural structure of layers was saved while sampling, a smaller stimulation of bioactivity was observed than in the case of mixing natural layers. No stimulation was recorded when the lime layer was removed.

The growth of improved pastures on acid soils. 1. The effect of superphosphate and lime on soil pH and on the establishment and growth of phalaris and lucerne

The response of improved pastures to the application of superphosphate is low on the acid sedimentary soils, of the Southern Tablelands of New South Wales, which contain high levels of exchangeable aluminium. An investigation was made into the effect of surface-applied fertilizers on soil pH and on the establishment and growth of lucerne and phalaris on these soils. At 6 weeks after the application of gypsum, superphosphate, or superphosphate plus potassium sulfate, soil pH (H2O) had decreased markedly. This effect extended to a depth of 20 cm, but decreased with time. Initially, lime application increased the pH of the surface soil only. When superphosphate was applied with lime the pH of the soil under the lime layer decreased to the same level as that found in the soil treated with superphosphate alone. Lime, however, had penetrated into the subsoil 102 weeks after application and substantially more so after 13 years. Soil pH (0.01 M CaCl2) was not depressed by the application of fertilizers. Growth and persistence of both species in the first summer were poor, but growth responses to phosphorus, lime and nitrogen increased after the first year. Lucerne showed large growth responses to lime, greater than those found on plots receiving nitrogen fertilizer. Lime reduced aluminium levels both in lucerne plants and in soil. It is suggested that the slow penetration of lime into the soil, the relatively quick effect of superphosphate in increasing subsoil acidity, and high soil aluminium levels are together responsible for the poor persistence and slow growth of both lucerne and phalaris in the early stages. The subsequent large dry matter responses of lucerne to lime are possibly related to increased nitrogen fixation and a lowering of plant and soil aluminium levels. It is suggested that the lime responses of phalaris are also related to lower aluminium levels.

Kinetics and Sulfur fixation in the reduction or oxidation of metal Sulfides mixed with lime

A number of metallurgical processes involve roasting of metal sulfides with oxygen or reduction of metal sulfides with hydrogen. In each case sulfur-bearing gases are emitted. Lime can be used to capture these sulfur-bearing gases. A model of this reaction occurring in a pellet made up of grains of metal sulfide and lime is presented. Specifically, a pellet made up of a mixture of metal sulfide and lime surrounded by a lime layer is considered. The computational investigation shows the distribution of lime necessary to achieve the maximum fixation of sulfur-bearing gases in the shortest time.

The Excavations at Tell Mevorach and the Late Phoenician Elements in the Architecture of Palestine

During the 1972-73 excavations at Tell Mevorach, an Iron Age stratum of the 10th century B.C. was unearthed (Stern: 1973b; 1974). Since the whole area of the site does not exceed one dunam (about 1000 sq. m.), it was not surprising that the plan of this stratum consisted of only a single large building of the four-room type, which was surrounded by a broad courtyard and paved with a thick layer of white lime, as was usual in public buildings of that period. The compound was completely encircled by a stone wall about I m. wide. The public nature of this building complex is shown by its comparatively large dimensions as well as by the fact that it was fortified. We believe that it served as a regional administrative center. Our conclusion receives additional support from the architectural remains: one dressed stone pier with marginal drafts, typical of the dressed ashlars of Israelite Samaria (fig. 1), and a crenellation stone in the steps form made of local sandstone (fig. 2). This crenellation stone closely resembles those previously found only in the palaces and public buildings of Israelite Megiddo and Samaria, and Judean Ramat Rahel (fig. 3; Lamon and Shipton 1939: 28-29, fig. 36; Crowfoot, Kenyon, and Sukenik 1942: 65, pl. 60:1; Aharoni 1964: 55-56, pls. 43:1, 44:1). Unfortunately, this was the only Iron Age stratum found on the site. Above it were three phases of a Late Persian Period level, dating to the 5th and 4th centuries B.c. In the lowest Persian phase, deep pits covered the entire excavated area. In the two upper phases, both of the 4th century B.C., the site was again occupied by a large building and surrounded by a casemate wall. The structure and its disposition may be interpreted as an agricultural estate. The plan of the building in both phases is quite complicated; it is hoped that more of

Effect of Lime, Inoculant, and Molybdenum Pelleting of Seed on Growth and Nitrogen Content of Crownvetch1

AbstractThere is a growing interest in the use of crownvetch (Coronilla varia L.) for hay or pasture. Crownvetch has been widely used on highway banks, but there have been problems with getting good stands. The present study was conducted to evaluate the influence of pelleting seed with lime, molybdenum, and inoculum on germination, growth, and N content of crownvetch.Gum arabic was used to secure materials to ‘Penngift’ crownvetch seed. A Culleoka silt loam soil with pH 5.0 and Grigg extractable Mo content of 0.56 kg/ha was used in greenhouse studies. Results showed that inoculant and Mo increased dry weight and N content of both tops and roots of crownvetch. Sodium molybdate at 70 g/ha was equally effective when pelleted to the seed or mixed uniformily with the soil. Neither pelleting nor uniform mixing of lime at the rate of 1.4 kg/ha influenced dry weights or N contents of roots or shoots in this soil, but uniform mixing of lime at the rate of 420 kg/ha significantly increased root weight. There was no significant treatment effect on germination but lime tended to reduce germination.Numbers of surviving rhizobia in laboratory tests varied with storage time and treatment. By three days after wetting with water and gum arabic many rhizobia had died. Greatest reductions in numbers occurred when sodium molybdate was present except when the inoculum was attached to the seed first and separated from the Mo by a layer of lime. Only small losses of rhizobia occurred from the third to the ninth day of storage.

The mechanism of the thermal decomposition of calcium carbonate

The decomposition of single sintered spheres of calcium carbonate has been investigated using a thermo-balance, modified to allow the simultaneous measurement of the temperature and weight of a decomposing sample. It has been shown that the decomposition reaction takes place on a definite boundary between the undecomposed carbonate, and the layer of porous lime formed outside it. This boundary moves towards the centre of the compact but remains spherical in shape. The rate of the reaction is controlled by the transfer of heat to this reaction boundary, and by the transfer of CO 2 away from it. This reaction mechanism is at variance with the mechanism proposed by previous workers who have suggested that the reaction is controlled by a chemical step at the reaction interface. Their conclusions have been based on the experimental observation of certain characteristics of the reaction that have been assumed to be symptomatic of chemically controlled reactions. This paper shows that transport controlled reactions can also display these characteristics, and so they do not provide any evidence as to the mechanism controlling the reaction. The modified thermo-balance has been used to measure the diffusion coefficient and thermal conductivity of the porous lime layer, and the mass and heat transfer coefficients to the surface of the compact. The values so obtained agree with values obtained from the literature. Three reaction models have been developed from which it is possible to predict the progress of the reaction for a single sphere in a constant environment. Predictions made by the two more complicated models are shown to agree very well with the experimental results.

NOTES ON MYXOMYCETES VIII

Specimens of a Didymium collected at Endegeest near Oegstgeest, a suburb of Leiden, on holly leaves, were put aside by Prof. Dr. W. K. H. Karstens as being near to Didymium squamulosum (Alb. & Schw.) Fries, but not identical with it. Some of the specimens were collected in August 1944 by Dr. S. J. van Ooststroom, whereas several other ones were collected in October of the following year by Prof. Karstens at the same locality; they are all very similar, and remarkable in the smooth white calcareous crust, which is distant from the membranous inner part of the peridium, and in the rather dark spores, which are nearly all encircled by a thin, sometimes fragmentary ridge. Comparison with a large number of specimens of D. squamulosum has convinced me that the specimens collected at Endegeest are indeed distinct from that species. LISTER, in a footnote to D. squamulosum (3rd ed. 1925, p. 118), mentions a form collected on holly leaves, but the description and figure prove that this is plainly D. squamulosum, and certainly not identical with the above mentioned specimens. The specimens from Endegeest are not identical with D. praecox de Bary either. The latter is described by Lister “as so inconstant that the name cannot be applied to mark even a variety”. However, D. praecox was described by Berlese in Saccardo (Syll. 1306) and by Massee (Mon. p. 223) (the two descriptions, probably based on that given by Rostafinsky, which was not seen by me, are practically identical) as possessing a double peridium. Study of a duplicate of de Bary’s type specimen in the Rabenhorst “Fungi Europaei” collection no. 367, 1861, preserved at the Rijksherbarium at Leiden (no. 910243-676), shows this to be D. squamulosum, as the crystalline lime crust closely adheres to the membranous inner layer of the peridium, a condition which is characteristic of this species; this is seen quite clearly at the time of dehiscence, as the two layers break away simultaneously. The spores were found by me to be 10-11 µ in diam., and not 8—9 µ, as they are said to be in Massee’s description (which, however, comes within the range allowed for the spores of this species by Lister and by Martin in their monographs, viz. 8-11 µ), and they are spinulose; some of the dark spinules are grouped in clusters, whereas the remaining ones are unevenly and sparingly scattered between these clusters. In the specimens collected at Endegeest the crystalline lime layer of the peridium, as stated above, is distinctly separated from the membranous inner layer, the latter, moreover, is often provided with light brown areolae, a feature which is seen also in D. nigripes and in D. melanospermum, but which I myself have not met with in D. squamulosum. However, Lister describes the inner peridium of the latter as “sometimes mottled with red-brown towards the base”; this, therefore, is a point which deserves further study. Other noteworthy points are that the spores of the new species are provided with a ridge and that the spinules are not arranged in clusters.