Adiabatic quantum-flux-parametron (AQFP) superconductor logic is a proven energy-efficient digital technology for various applications. To address the scalability challenges of this technology, we investigated AQFP shift registers with footprint area reduced by 25% respect to prior work and >2× denser overall circuit designs obtained eliminating previously used free space between AQFPs. We also cells different flux trapping moats in superconducting ground plane as well compact that took...

A study was carried out to evaluate the relative effects of soil compaction on water retention characteristics a range soils in forest plantations summer rainfall regions South Africa. In all cases resulted ‘flattening’ S-shaped retentivity curve expressed either mass or volumetric basis. This had implicit effect lowering release index (a log-linear plot matric potential against content). clear relationship between available capacity (AWC) and bulk density type not discernible since changes...

Abstract The EM‐38 electromagnetic induction sensor of Geonics Ltd. (Canada) is a most useful instrument for rapid field identification and mapping soil salinity. Interpretation measurements in terms meaningful parameters salinity difficult, however, due largely to the non‐uniform response distribution with depth. Various models have been proposed that allow conversion made on this electrical conductivity bulk (EC , as measured four‐electrode probe) or EC saturation extract e ). Seven these...

To calculate nutrient requirement it is necessary to know how much of that must be applied overcome any buffering effects and raise the test value a desired level. A glasshouse study was conducted on wide range Natal soils establish this information for phosphorus. The upper 200-mm depth at 54 sites sampled. Soils varied greatly in texture (4–83% clay), organic carbon (0.2–9.2%) clay mineralogy (kaolinitic-sesquioxic through illitic smectitic). Soil from each site treated with four levels P...

Water treatment residue (WTR), a waste by-product of the 'drinking' water industry, consists mainly clay and fine silt flocculated out suspension by chemicals such as polyelectrolytes aluminium sulfate. This was disposed almost exclusively in landfill, but land is increasingly being seen possible alternative for this form waste. A key concern, however, that should WTR decompose to its constituent fractions, could cause blockage pores decrease hydraulic properties soil. To test hypothesis, 2...

Phosphorus (P) sorption poses a severe constraint on the ability of many soils to supply adequate amounts P plants. In an effort quantify capacities in Natal, isotherms 50 topsoils from number localities province were established. The amount sorbed at solution level 0.2 mg L−1, defined as standard requirement, varied 5 1174 kg−1. Standard requirement was greatest highly weathered clay and lowest sands. Various soil parameters correlated with isotherm slope L−1. Oxalate-extractable aluminium,...

An investigation of water conservation as affected by different primary tillage methods was conducted on a soil the Doveton series (fine-loamy, mixed, thermic family Rhodic Paleudults), where direct sampling technique used to monitor soil-water profiles. Soil samples were taken for period just prior early winter two weeks before maize crop flowered. The results showed that practices which maintain higher levels surface residues retained more than their mode disturbance leave surfaces...

Abstract Soil texture often plays an important role in the interpretation of soil analytical data for fertilizer advisory purposes. A reliable and inexpensive method clay content estimation is, therefore, a requirement most laboratories. This note discusses use sample density (i.e. mass scooped volume soil) as index content. strong relationship was found to exist between content, such estimates were superior those obtained by experienced pedologists using “finger test” procedure. The this...

Abstract In order to calculate the potassium (K) fertilizer requirement, it is necessary know how much of this nutrient element must be applied in overcome any buffering effects and raise soil test value a desired level. A glasshouse study was conducted on wide range KwaZulu‐Natal (South Africa) soils establish information. The topsoil (0–200 mm) at 51 sites sampled. Soils varied greatly texture (4–83% clay), organic carbon (0.2–9.2%), clay mineralogy (kaolinitic‐sesquioxic through illitic...

Soils, collected from the south-eastern Transvaal, Natal north coast and more arid areas of interior, were examined using physical, chemical mineralogical methods. Most soils associated with particular management problems such as poor internal drainage, high bulk density or clay dispersion. The results investigation confirm that there is a relationship between composition physical behaviour. Poorly drained tended to be dominated by smectite minerals, while dispersive compact had mixed...

Adiabatic quantum-flux-parametron (AQFP) logic is a proven energy-efficient superconductor technology for various applications. To address the scalability challenges, we investigated AQFP shift registers with footprint area reduced by 25% respect to prior work and more than 2x denser overall designs obtained eliminating previously used free space between AQFPs. We also cells different of flux trapping moats in superconducting ground plane as well compact that took advantage smaller feature...

A commercially available salinity sensor (model EM-38 of Geonics Ltd., Canada) has been developed for diagnosing and quantifying soil in the field. There is a need, however, to calibrate instrument reading against more commonly used measure salinity. Linear regression equations are reported that allow interpretation field readings terms electrical conductivity saturation extract (ECe) measured laboratory. Instrument measurements samples were taken at some 110 sites on various irrigation...

Abstract Adiabatic quantum-flux-parametron (AQFP) logic stands as an energy-efficient superconductor family relying on ac excitations. Though a four-phase clocking scheme has been commonly applied to excite and clock AQFP circuits, the cost of multiple sources long between-stage latency (a quarter cycle) remain unsatisfactory. These drawbacks are more severe for sequential logics, where feedback loops require both down-flow reverse-flow gates, necessitating extra buffers imposing limit...

Acid, P-deficient soils with a large capacity to immobilize P favour the rapid decomposition of apatite. Such are widespread in east South Africa and possibility exists that Langebaan rock phosphate (Langfos) may be more cost-effective source than superphosphate on these soils. This study compared effectiveness granular Langfos double pot experiment using strongly P-fixing Balmoral clay (Typic Haplorthox) weakly Avalon sandy loam (Plinthic Paleu- dult). Five rates (0, 100, 250, 500 1 000 mg...

Problems currently exist in the interpretation of soil test values for soils fertilized with rock phosphate. This study was undertaken to compare ability four extradants (Ambic, Bray 1, Mehlich 3 and modified Truog) assess plant available phosphorus superphosphate or Langebaan phosphate (Langfos). A Balmoral clay (Typic Haplorthox) an Avalon sandy loam (Plinthic Paleudult), adjusted three levels acidity Langfos, were consecutively cropped times maize (Zea mays L.) a glasshouse. Soil samples...

Abstract A previous investigation showed that Langebaan rock phosphate (Langfos) was not an effective substitute for superphosphate. However, in the light of reports P availability is enhanced when (PR) and monocalcium are combined, improvement Langfos effectiveness considered possible if mixed with To investigate this, Avalon sandy loam a Balmoral clay were treated total 0, 50, 100, 175, 250 350 mg kg−1 and.0, 200, 400, 800 1600 kg−1, respectively, applied as mixture superphosphate to...

Signal integrity of transmitted data is critical for achieving highly dense, large-scale superconductor circuits. Transmission line effects, such as signal reflections, are investigated and concepts from microwave circuit theory conventional digital logic circuits applied to AQFP The lossless transmission model used interconnection modelling. frequency content timing characteristics signals analytically predict a maximum propagation delay 6.1 ps before failure due reflections. This coincides...

Abstract Soil compressibility is an important soil physical property in the prediction of compaction behavior. The compression index, C , as a measure compressibility, was determined for wide range South African forest soils and compared with existing models that utilize clay content independent variable. These were tested using model performance technique distinguished between systematic (bias) nonsystematic (random) errors. maximum max adequately predicted all orders this study possessed...