Soil surface temperature and mortality in land snails: implications for successful management

2003 ◽  
Vol 43 (11) ◽  
pp. 1351 ◽  
Author(s):  
V. Kempster ◽  
S. Charwat
Keyword(s):  
Laboratory Experiments ◽  
Control Strategies ◽  
High Surface ◽  
Soil Surface ◽  
Land Snails ◽  
Successful Management ◽  
Economic Problems ◽  
Surface Temperatures ◽  
Theba Pisana ◽  
Soil Surface Temperature

Three species of land snails, Theba pisana (Müller, 1774), Cernuella virgata (Da Costa, 1778) and Cochlicella acuta (Müller, 1774), introduced to Australia from the Mediterranean region, cause significant economic problems in harvested crops in southern Australia. One of the strategies for post-harvest control of these snails involves stubble management to knock the snails onto the hot ground during summer. Farmers report variable results with this strategy, which could be due to varying heat tolerances between the 3 species. In a series of laboratory experiments, field-collected snails of the 3 species were tested for their ability to survive high surface temperatures for varying periods of time. The results reported here indicate differences between the 3 species in their tolerance of soil surface temperatures, and suggest that the variable results noted in the field are due at least in part to the differing heat tolerances of the 3 species. When adult snails were placed in incubators at a constant temperature, all T. pisana died after 3 h at 55°C, while C. virgata and C. acuta survived longer, with 100% mortality only after 2 successive 6-h exposures at 55°C. Weight loss of snails was measured after heat treatment to estimate water loss under these conditions. Recommendations are made for more effective mechanical control strategies for snails in the field during summer.

Interactions between the land snails Theba pisana and Cernuella virgata in the laboratory

2020 ◽  
Author(s):  
Geoff H Baker
Keyword(s):  
Laboratory Experiments ◽  
Distribution Patterns ◽  
Land Snails ◽  
Snail Species ◽  
Agricultural Pests ◽  
Large Numbers ◽  
Small Scales ◽  
Novel Method ◽  
Theba Pisana ◽  
Inhibitory Components

ABSTRACT Two Mediterranean snails, Theba pisana and Cernuella virgata, are agricultural pests in southern Australia. The two species are rarely found together in large numbers in the field, at small scales (<1 m2). In laboratory experiments, the presence of T. pisana reduced the survival of C. virgata, but only when food (carrot + lettuce) was provided. When C. virgata was exposed to only the mucus trails and faeces of T. pisana, produced while feeding on lettuce, both the survival and activity of C. virgata were reduced. When carrot was substituted for lettuce, there was less effect. In addition, when C. virgata was exposed to T. pisana’s faeces only, derived from access to a mix of lettuce and carrot, there was no effect on C. virgata’s survival. The observed reductions in the survival of C. virgata were stronger in autumn (the breeding season for both snail species) compared with spring. Inhibitory components within the mucus trails of T. pisana may (1) help explain the observed distribution patterns of the two species at small scales in the field and (2) provide a novel method for control of pest populations of C. virgata, in some situations.

scholarly journals Experimental investigation of the machining characteristics in diamond wire sawing of unidirectional CFRP

2021 ◽  
Author(s):  
Lukas Seeholzer ◽  
Stefan Süssmaier ◽  
Fabian Kneubühler ◽  
Konrad Wegener
Keyword(s):  
Surface Quality ◽  
Influencing Factors ◽  
Material Properties ◽  
High Surface ◽  
Workpiece Surface ◽  
High Surface Quality ◽  
High Productivity ◽  
Surface Temperatures ◽  
Process Forces ◽  
The Wire

AbstractEspecially for slicing hard and brittle materials, wire sawing with electroplated diamond wires is widely used since it combines a high surface quality with a minimum kerf loss. Furthermore, it allows a high productivity by machining multiple workpieces simultaneously. During the machining operation, the wire/workpiece interaction and thus the material removal conditions with the resulting workpiece quality are determined by the material properties and the process and tool parameters. However, applied to machining of carbon fibre reinforced polymers (CFRP), the process complexity potentially increases due to the anisotropic material properties, the elastic spring back potential of the material, and the distinct mechanical wear due to the highly abrasive carbon fibres. Therefore, this experimental study analyses different combinations of influencing factors with respect to process forces, workpiece surface temperatures at the wire entrance, and the surface quality in wire sawing unidirectional CFRP material. As main influencing factors, the cutting and feed speeds, the density of diamond grains on the wire, the workpiece thickness, and the fibre orientation of the CFRP material are analysed and discussed. For the tested parameter settings, it is found that while the influence of the grain density is negligible, workpiece thickness, cutting and feed speeds affect the process substantially. In addition, higher process forces and workpiece surface temperatures do not necessarily deteriorate the surface quality.

Using soil surface temperature to assess soil evaporation in a drip irrigated vineyard

2013 ◽  
Vol 116 ◽  
pp. 128-141 ◽  
Author(s):  
B.L. Kerridge ◽  
J.W. Hornbuckle ◽  
E.W. Christen ◽  
R.D. Faulkner
Keyword(s):  
Surface Temperature ◽  
Soil Surface ◽  
Soil Evaporation ◽  
Soil Surface Temperature

Analytical Model to Predict Nonhomogeneous Soil Temperature Variation

1995 ◽  
Vol 117 (2) ◽  
pp. 100-107 ◽  
Author(s):  
M. Krarti ◽  
D. E. Claridge ◽  
J. F. Kreider
Keyword(s):  
Thermal Properties ◽  
Soil Temperature ◽  
Temperature Variation ◽  
Analytical Model ◽  
Soil Surface ◽  
Deep Soil ◽  
Soil Thermal Properties ◽  
Order Of Magnitude ◽  
Soil Surface Temperature ◽  
Annual Time

This paper presents an analytical model to predict the temperature variation within a multilayered soil. The soil surface temperature is assumed to have a sinusoidal time variation for both daily and annual time scales. The soil thermal properties in each layer are assumed to be uniform. The model is applied to two-layered, three-layered, and to nonhomogeneous soils. In case of two-layered soil, a detailed analysis of the thermal behavior of each layer is presented. It was found that as long as the order of magnitude of the thermal diffusivity of soil surface does not exceed three times that of deep soil; the soil temperature variation with depth can be predicted accurately by a simplified model that assumes that the soil has constant thermal properties.

The N-factor in Natural Landscapes: Variability of Air and Soil-Surface Temperatures, Kuparuk River Basin, Alaska, U.S.A.

2001 ◽  
Vol 33 (2) ◽  
pp. 140-148 ◽  
Author(s):  
Anna E. Klene ◽  
Frederick E. Nelson ◽  
Nikolay I. Shiklomanov ◽  
Kenneth M. Hinkel
Keyword(s):  
River Basin ◽  
Soil Surface ◽  
Surface Temperatures ◽  
Natural Landscapes ◽  
Kuparuk River

Effect of Environmental Factors on Germination and Emergence of Shortawn Foxtail (Alopecurus aequalis)

Weed Science ◽  
2017 ◽  
Vol 66 (1) ◽  
pp. 47-56 ◽  
Author(s):  
Ning Zhao ◽  
Qi Li ◽  
Wenlei Guo ◽  
Lele Zhang ◽  
Lu’an Ge ◽  
...  
Keyword(s):  
Seed Germination ◽  
Osmotic Potential ◽  
Control Strategies ◽  
Abiotic Factors ◽  
Germination Rate ◽  
Seedling Emergence ◽  
Soil Surface ◽  
Burial Depth ◽  
Effective Measure ◽  
Wide Range

Shortawn foxtail is an invasive grass weed infesting winter wheat and canola production in China. A better understanding of the germination ecology of shortawn foxtail would help to develop better control strategies for this weed. Experiments were conducted under laboratory conditions to evaluate the effects of various abiotic factors, including temperature, light, pH, osmotic stress, salt concentration, and planting depth, on seed germination and seedling emergence of shortawn foxtail. The results showed that the seed germination rate was greater than 90% over a wide range of constant (5 to 25C) and alternating (15/5 to 35/25C) temperatures. Maximum germination occurred at 20C or 25/15C, and no germination occurred at 35C. Light did not appear to have any effect on seed germination. Shortawn foxtail germination was 27% to 99% over a pH range of 4 to 10, and higher germination was obtained at alkaline pH values ranging from 7 to 10. Seed germination was sensitive to osmotic potential and completely inhibited at an osmotic potential of −0.6 MPa, but it was tolerant to salinity: germination even occurred at 200 mM NaCl (5%). Seedling emergence was highest (98%) when seeds were placed on the soil surface but declined with the increasing burial depth. No seedlings emerged when seeds were buried 6-cm deep. Deep tillage could be an effective measure to limit seed germination from increased burial depth. The results of this study will lead to a better understanding of the requirements for shortawn foxtail germination and emergence and will provide information that could contribute to its control.

scholarly journals RESEARCH AND EVALUATION OF KART NOISE SPREAD INTO THE LIVING ENVIRONMENT / GOKARTŲ KELIAMO TRIUKŠMO SKLAIDOS Į GYVENAMĄJĄ APLINKĄ TYRIMAI IR VERTINIMAS

2014 ◽  
Vol 6 (4) ◽  
pp. 356-361
Author(s):  
Giedrius Juozaponis ◽  
Raimondas Grubliauskas
Keyword(s):  
Wind Speed ◽  
Experimental Studies ◽  
Soil Surface ◽  
Sound Level ◽  
Living Environment ◽  
Noise Levels ◽  
Noise Propagation ◽  
Soil Surface Temperature ◽  
Service Data ◽  
Living Area

The paper examines kart noise propagation in the living environment and sought measures for suppressing it. To conduct experimental studies, precision sound level analyzer Bruel & Kjaer 2260th has been used. In cooperation with the Lithuanian Hydrometeorological Service, data on relative humidity, wind speed and direction, soil surface temperature and air temperature have been applied. According to the Lithuanian Hygiene Standard HN 33:2011 Noise Thresholds in Residential and Public Buildings and Their Environment, the areas with an elevated noise level are identified thus selecting noise reduction measures aimed at reducing noise levels up to the permitted ones. The analysis of the obtained results has focused on the regularities between noise propagation and meteorological events and their impact on the spread of noise. The environmental factors more or less influencing the climate and noise spread in the living area have been determined. With reference to the received information, the ways to reduce noise have been suggested. Straipsnyje nagrinėjamas gokartų keliamo triukšmo sklidimas į gyvenamąją aplinką ir ieškoma priemonių jam slopinti. Eksperimentiniams tyrimams atlikti buvo naudojamas precizinis garso lygio analizatorius „Bruel&Kjaer 2260“. Bendradarbiaujant su Lietuvos hidrometeorologijos tarnyba panaudoti santykinės oro drėgmės, vėjo stiprumo ir krypties, dirvožemio paviršiaus temperatūros bei oro temperatūros duomenys. Vadovaujantis Lietuvos higienos normomis HN 33:2011 „Triukšmo ribiniai dydžiai gyvenamuosiuose ir visuomeninės paskirties pastatuose bei jų aplinkoje“ nustatomos zonos, kuriose triukšmo lygis yra viršijamas, ir parenkant triukšmo mažinimo priemones siekiama triukšmą sumažinti iki leidžiamųjų normų. Gautų rezultatų analizės metu ieškoma dėsningumų tarp triukšmo sklidimo ir meteorologinių reiškinių bei jų daroma įtaka triukšmo plitimui. Nustatomi aplinkos klimato veiksniai, darantys įtaką ar mažiau veikiantys triukšmo sklaidą gyvenamojoje teritorijoje. Atsižvelgiant į gautus rezultatus siūlomi triukšmo mažinimo būdai.

Variothermal Foam Injection Molding - Dimensional Stability with High Surface Quality

2017 ◽  
Vol 36 (3) ◽  
pp. 151-166 ◽  
Author(s):  
Christian Hopmann ◽  
Nicolai Lammert ◽  
Yuxiao Zhang
Keyword(s):  
Surface Quality ◽  
Surface Defects ◽  
Control Strategies ◽  
High Surface ◽  
Skin Layer ◽  
High Surface Quality ◽  
Major Disadvantage ◽  
Scope Of Application ◽  
Specific Material ◽  
Foam Injection Molding

Thermoplastic foam injection moulding offers various advantages for both processing and product design. Despite its many benefits, the moderate surface quality still constitutes a major disadvantage of this process. The mould temperature can be controlled dynamically to improve the surface quality. Different dynamic temperature control strategies are employed and analysed regarding their effectiveness and scope of application. Mould temperatures above the specific material transition temperatures allow the surface defects to be cured and enable the production of foamed thermoplastic parts with surface qualities comparable to those of the compact reference samples. The high mould temperatures during the injection phase alter the foam structure and the skin layer thicknesses, which impacts the mechanical properties.

scholarly journals Development of a Control Systems Training Module for Application on Undergraduate Engineering Classes

2020 ◽  
Author(s):  
Luciano A. E. Silva ◽  
Ivan Barroso ◽  
Alexsander Menezes ◽  
Alessandro R. L. Zachi ◽  
Milena F. Pinto ◽  
...  
Keyword(s):  
Control Systems ◽  
Laboratory Experiments ◽  
Control Strategies ◽  
Low Cost ◽  
Theory And Practice ◽  
Technological Advancement ◽  
Training Module ◽  
Undergraduate Engineering ◽  
Student Access ◽  
Training Control

Student access to laboratory experiments is critical in undergraduate engineering courses since it integrates theory and practice. The access of students to such practical examples helps them to understand and apply what is learned. However, due to rapid technological advancement, educational kits can quickly become obsolete. Besides, there are many known commercial platforms for training.Many of them have steep prices, which makes their availability dicult for every student. The present work proposes a low-cost ATMEGA-based system as the main device for an educational tool for training Control System Theory. The system enables the students to test dierent control strategies through the use of a simple educational kit.

scholarly journals Determination of the united quality latent index of adaptability (UQLIA) and contribution of some environmental parameters to it for Deschampsia antarctica populations, Galindez island (Maritime Antarctic) season 2017/2018

2019 ◽  
Vol 16 (2) ◽  
pp. 190-202
Author(s):  
I. Y. Parnikoza ◽  
N. Y. Miryuta ◽  
V. Y. Ivanets ◽  
E. O. Dykyi
Keyword(s):  
Surface Temperature ◽  
Pairwise Comparison ◽  
Environmental Parameters ◽  
Soil Surface ◽  
Deschampsia Antarctica ◽  
Near Surface ◽  
Soil Surface Temperature ◽  
Experimental Populations ◽  
The Individual

The purpose of our work has been to determine the indicator of complex adaptability — the United Quality Latent Index of Adaptability (UQLIA) for the experimental populations of Deschampsia antarctica É. Desv. and study the contribution to it of some environmental factors such as the near soil surface temperature and organogens content. Materials and methods. The determination of UQLIA was based on a pairwise comparison of the differences between investigated parameters of populations by mathematical regression techniques. The soil surface temperature was measured by loggers installed near plants in each locus during April 2017 – April 2018. Results and conclusions. Temperature fluctuations were described during December 2017 – February 2018 for twelve experimental populations of D. antarctica and one control fragment of moss turf subformation from Galindez Island. Significant variations in average daily near surface temperature were observed during the study period between populations, especially in December and January. The UQLIA of D. antarctica for this season was calculated on the basis of the projective cover, biometric indices of generative plants and the content of protective and reserve proteins in seeds for the eleven populations. The values of the United Soil Surface Temperature Influence Index (UTII) for the season summer months and the United Organogens Content in Soil Influence Index (UOCSII) have been calculated for the individual parameters of D. antarctica plants adaptability. The reliable contribution of UTII to ULIA has been shown for December and January, at the moment of the greatest variation of soil surface temperature. UOCSII provided a reliable contribution to the ULIA only in the amount of UTII. Keywords: Deschampsia antarctica, United Quality Latent Index of Adaptability (UQLIA), contribution of soil surface temperature and organogens content to complex adaptability.

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