Three-dimensional computer-aided human factors engineering analysis of a grafting robot

The objective of this research was to conduct a human factors engineering analysis of a grafting robot design using computer-aided 3D simulation technology. A prototype tubing-type grafting robot for fruits and vegetables was the subject of a series of case studies. To facilitate the incorporation of human models into the operating environment of the grafting robot, I-DEAS graphic software was applied to establish individual models of the grafting robot in line with Jack ergonomic analysis. Six human models (95th percentile, 50th percentile, and 5th percentile by height for both males and females) were employed to simulate the operating conditions and working postures in a real operating environment. The lower back and upper limb stresses of the operators were analyzed using the lower back analysis (LBA) and rapid upper limb assessment (RULA) functions in Jack. The experimental results showed that if a leg space is introduced under the robot, the operator can sit closer to the robot, which reduces the operator's level of lower back and upper limbs stress. The proper environmental layout for Taiwanese operators for minimum levels of lower back and upper limb stress are to set the grafting operation at 23.2 cm away from the operator at a height of 85 cm and with 45 cm between the rootstock and scion units.     

An Environmental Risk Assessment of Radon in Lantian Karst Cave of Shaanxi,China

Water, Air, & Soil Pollution - The radiation dose and environmental health risk of radon concentration in the Lantian karst cave of China to guides and visitors were estimated based on the...     

Effect of Bacillus subtilis on granite weathering: A laboratory experiment

We performed a comparative experiment to investigate: (1) how the ubiquitous soil bacterium Bacillus subtilis weathers granite; and (2) which granite-forming minerals weather more rapidly via biological processes. Batch system experiments (granite specimen in a 500 ml solution including NaCl, glucose, yeast extract and bacteria B. subtilis at 27 °C) were carried out for 30 days. Granite surfaces were observed by SEM before and after the experiment. B. subtilis had a strong influence on granite weathering by forming pits. There were 2.4 times as many pits and micropores were 2.3 times wider in granite exposed to B. subtilis when compared with bacteria-free samples. B. subtilis appear to preferentially select an optimum place to adhere to the mineral and dissolve essential elements from the mineral to live. Plagioclase was more vulnerable to bacterial weathering than biotite among the granite composing minerals.     

Performance of cowpea cultivars when grown as an intercrop with maize of contrasting maturities

A field trial was conducted during the rainy seasons of 2008 and 2009 at Samaru in northern Guinea savannah of Nigeria to determine the performance of semi-determinate and indeterminate cowpea cultivars intercropped with extra early, early and late maize cultivars. The trial was laid out in a randomized complete block design (RCBD) having treatments arranged as a split-plot factorial. Transmitted radiation was reduced by 49–63% due to shading by the maize plants. Similarly, intercropping cowpea with maize reduced intercepted radiation, fodder yield and grain yield of cowpea by 59–70%, 39–51% and 45–62%, respectively. Intercepted radiation and yields of intercropped cowpea were lower for late maize which maintained high leaf area over a longer period of time. This is supported by the higher plant height, higher leaf area index (LAI) and reduced transmitted radiation recorded in late maize compared with extra early and early maize. Extra early and early maize were less competitive with cowpea because of shorter period of association in addition to permitting higher radiation. Crop value of maize plus cowpea was higher than that of sole cowpea ($2616.8 vs. $1218.7 ha^?1) because higher combined yield was achieved by a more efficient use of resources in the intercrop. Therefore, cowpea cultivar may be intercropped with extra early maize.     

Die Aufnahme von137Cs und 90Sr durch verschiedene sommerrapsgenotypen aus dem Boden*

Die Aufnahme von ¹³⁷Cs und ⁹⁰Sr durch verschiedene Sommerrapsgenotypen aus kontaminiertem Boden wurde geprüft. Statistisch gesicherte Unterschiede bei der Aufnahme von Radionukliden zwischen den Genotypen konnten festgestellt werden. Die Aufnahme von ¹³⁷Cs und ⁹⁰Sr ist bei den einzelnen Sorten nicht gleichsinnig. Nur ein geprüfter Genotyp nahm sowohl geringe Mengen von ¹³⁷Cs, als auch von ⁹⁰Sr auf. Die mittleren jährlichen Schwankungen in der Radionuklidaufnahme waren größer, als die Unterschiede zwischen den Genotypen.     

Effect of crop residue biochar on soil acidity amelioration in strongly acidic tea garden soils

Strongly acidic soil (e.g. pH < 5.0) is detrimental to tea productivity and quality. Wheat, rice and peanut biochar produced at low temperature (max 300 °C) and differing in alkalinity content were incorporated into Xuan‐cheng (Ultisol; initial pH_{soil/water = 1/2.5} 4.12) and Ying‐tan soil (Ultisol; initial pH _{soil/water = 1/2.5} 4.75) at 10 and 20 g/kg (w/w) to quantify their liming effect and evaluate their effectiveness for acidity amelioration of tea garden soils. After a 65‐day incubation at 25 °C, biochar application significantly (P < 0.05) increased soil pH and exchangeable cations and reduced Al saturation of both tea soils. Association of H⁺ ions with biochar and decarboxylation processes was likely to be the main factor neutralizing soil acidity. Further, biochar application reduced acidity production from the N cycle. Significant (P < 0.05) increases in exchangeable cations and reductions in exchangeable acidity and Al saturation were observed as the rate of biochar increased, but there were no further effects on soil pH. The lack of change in soil pH at the higher biochar rate may be due to the displacement of exchangeable acidity and the high buffering capacity of biochar, thereby retarding a further liming effect. Hence, a significant linear correlation between reduced exchangeable acidity and alkalinity balance was found in biochar‐amended soils (P < 0.05). Low‐temperature biochar of crop residues is suggested as a potential amendment to ameliorate acidic tea garden soils.     

Sensitive enzyme immunoassay of cephalexin residues in milk, hen tissues, and eggs

A sensitive enzyme immunoassay for cephalexin (CEX) was developed using the rabbit antiserum to CEX, beta-D-galactosidase-labeled CEX, and a double-antibody separation method. The immunogen of CEX was prepared by coupling the amino group of CEX to thiol groups introduced into bovine serum albumin by the use of N-(m-maleimidobenzoyloxy)succinimide as a cross-linker. Highly titered antiserum to CEX was produced in rabbits immunized with the immunogen. Enzyme labeling of CEX with beta-D-galactosidase was done by using N-(gamma-maleimidobutyryloxy)succinimide as the cross-linker. The limit of detection was 30 ng CEX/mL sample solution. Application of the method to CEX drug residues detected 30 ng/mL in milk, 60 ng/g in egg yolk, and 400 ng/g in hen tissue.     

Ammonium-calcium exchange equilibria in soils and weathered pumices that differ in cationexchange materials

The retention of NH₄+ and Ca²+ on soil and weathered pumice samples containing constant and/or variable charge components was measured in different NH₄CI-CaCl₂ solutions. The NH₄+/Ca²+ selectivity of each sample was evaluated using a quotient of the partition of NH₄+ on the exchange sites and in the solution relative to that of Ca²+. It increased with decreasing pH and increasing NH₄Cl-CaCl₂ concentration for a given equivalent fraction of NH₄+ in the solution. These effects were quantitatively explained in terms of the changes of NH₄+ and Ca²+ concentrations in the solution and in the diffuse double-layer of the ion-exchange material as predicted by the law of mass action and the electric double layer theory. The NH₄+/Ca²+ selectivity of different exchange materials showed a similar variation among their exchange sites and increased in the order humus, allophane and imogolite (Si/Al ratio 0.5) < allophane (Si/Al ratio 1.0), montmorillonite < vermiculite, illite < halloysite. The origin of negative charge, the steric features around the exchange sites and clay-humus interaction are suggested as being important in determining the NH₄+/Ca²+ selectivity.