Spectrophotometric determination of trace amounts of molybdenum in vegetal and tobacco tissues with a new chromogenic reagent, dimethoxyhydroxyphenylflurone

A simple method for the direct determination of trace molybdenum in vegetal and tobacco tissues with selectivity and sensitivity is reported. The advantages are the high sensitivity, ease of operation, good reproducibility, and simplicity of apparatus. In the presence of Triton X-100 and sulfuric-phosphoric acid medium, a new chromogenic reagent, dimethoxydroxyphenylflurone, forms a red complex with molybdenum(VI). The molar absorptivity is obeyed in the range of 0-8 microg/25 mL for molybdenum(VI). Most metal ions and 35000-fold amounts of iron do not interfere with the determination of molybdenum. The proposed method has been successfully used for the determination of trace amounts of molybdenum in vegetal and tobacco tissues.     

The prediction of seedy grape drying rate using a neural network method

This paper presents an application which uses Feedforward Neural Networks (FNNs) to model the nonlinear behaviour of the drying of seedy grapes. First, a novel type of dryer for experimentally and mathematically evaluating the thin-layer drying kinetics of seedy grapes is developed. In the developed drying system, an expanded-surface solar air collector, a solar air collector with Phase-Change Material (PCM) and drying room with swirl element have been particularly included. Secondly, the drying rate is estimated as an exponential-type equation using non-linear regression analysis. Thirdly, the drying rate of seedy grapes is estimated using an FNN. Finally, the performance of the FNN model is compared with those of nonlinear and linear regression models by means of the root mean square errors, the mean absolute errors, and the correlation coefficient statistics. The results indicate that the FNN is more accurate and performed more consistently than alternative approaches employed in estimating drying rate.     

A study of the effectiveness of post-treatment after hair straightening process

In order to minimise the hair damage due to hair straightening process, post-treatment is recommended to protect the damaged hair from further depreciation and breakage. However, few reported quantitatively about the effectiveness of post-treatment after hair straightening process. Therefore, the aim of this paper will investigate the effectiveness of post-treatment methods for chemically straightened hairs. The effectiveness will be evaluated through different analytical methods such as scanning electron microscopy (SEM), diffuse reflectance spectrophotometry, tensile strength test and urea bisulphite solubility test for the properties related to morphological structure, hair colour change, tensile strength as well as chemical damage respectively. From the findings of the instrumental results, it was obvious that the application of post-treatments would improve the lustre of the damaged hair by giving higher value in lightness when compared with the raw hair control sample. Furthermore, the strength property of the post-treated hair increased when compared with the chemically straightened hair. This was due to the fact that the film-forming agents of conditioning products formed a protective layer and smooth surface on the fibre surface.     

Potato Production and Breeding in China

China is the world’s leading producer of potatoes, growing 22% of all potatoes. Production continues to rise, owing to increases in both land devoted to potato production and yield per hectare. Most potato production occurs in the northern and southwest regions of the country. The processing of coarse starch is the most important component of the potato processing industry in China, but other processing industries, such as crisps and French fries, are expanding. Major production constraints include inadequate germplasm resources for cultivar development, the lack of high quality seed potatoes, and limited access to equipment for mechanized cultivation, planting, fertilizing, spraying, and harvesting. Additional weaknesses in storage and transportation technologies must be addressed, as they are the major constraints for the healthy development of the potato industry. The introduction and improvement of these technologies will ensure the sustainable development of the potato industry in China.     

Response of Stipa bungeana and Pennisetum flaccidum to urine of sheep in steppe grassland of north‐western China

Urine [12·3 g nitrogen (N) L^?1], collected from native Tan sheep in rangeland of the Loess Plateau in north‐western China, was applied to vegetation patches dominated by Stipa bungeana (C₃ grass) or Pennisetum flaccidum, (C₄ grass) at either 0, 1·0, 2·0 or 4·0 L urine m^?2 in early‐, mid‐, or late‐growing season, and herbage mass and tiller number per sample recorded, allowing calculation of the respective contributions of increases in tiller weight and tiller density to the response from N in urine. Such records were made three times in the growing season of application of urine, and at the end of the following growing season. Responses to urine were of the order of 1 and 5 kg herbage DM kg^?1 N applied for S. bungeana and P. flaccidum, respectively. Except for early‐season application, responses of S. bungeana were mainly expressed in the season following urine application whereas responses of P. flaccidum tended to be expressed within the year of urine application, although with a residual response in the following year. The general pattern was for a tiller density‐mediated response in the period immediately after application, followed later by a tiller weight‐mediated response. Taken together with other recent research, S. bungeana can be considered a stress‐tolerating species with a limited response to N application and P. flaccidum an opportunist species able to capitalize on increased N supply.     

Uptake efficiency of 15N-urea in flooded and aerobic rice fields under semi-arid conditions

Paddy and Water Environment - The sustainability of traditional rice (Oryza sativa L.) cultivation in many Asian countries is being questioned due to severe water shortage conditions, envisaging...