The second law requirement that the Onsager L matrix for isothermal diffusion in a stable solution be positive definite and the stability condition for such a solution that the Hessian of the Gibb's free energy be positive definite impose on the diffusion D matrix the condition that it always have real and positive eigenvalues. This condition ensures that solutions of the differential equations for diffusion will always relax in a nonperiodic way.

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Glyphosate [N-(phosphonomethyl)glycine] is a widely used phosphonate herbicide for different agricultural purposes. Due to its widespread use, suspected toxicity, and ubiquitous bioaccumulation, it is one of the most harmful contaminants...

Black cumin (Nigella sativa L.; Family-Ranunculaceae) is an important spice crop. Mature seeds are consumed for edible and medical purposes and also used as a food additive and flavour. Seed of black cumin has great potentiality as spice crop due to nutritive and medicinal values. The experiments were carried out at Bangabandhu Sheikh Mujibur Rahman Agricultural University, Gazipur during 2011 to 2012 to determine optimum planting time for seed production of black cumin. The experiment was two factorials.

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Irrigation system management in Pakistan is undergoing institutional reforms to implement participatory irrigation management (PIM) with the involvement of farmers. This study was undertaken to examine the impacts of institutional reforms by comparing the irrigation service delivery of Hakra 3-R distributary operated by the provincial irrigation department, and Hakra 4-R distributary operated by the farmers' organization (FO). The present study is based on detailed analysis of 18 watercourses, 9 on each of the secondary canal (distributary). The investigations were focused on parameters such as delivery performance ratio (DPR), spatial coefficient of variation (CV S ), temporal coefficient of variation (CV T ), farmers' net income and land and water productivities. Results of the study revealed that the 4-R distributary has a relatively superior irrigation service delivery in comparison to the 3-R distributary. Average net income, land and water productivities were higher on the 4-R distributary than the 3-R distributary. Based on the results of this study, it is concluded that the overall performance of the FO-managed irrigation canal (4-R) was better than the state-managed canal (3-R), but the performance of the former was also below expectations. Copyright © 2014 John Wiley & Sons, Ltd.key words: participatory irrigation management; delivery performance ratio; coefficient of variation; water productivity; income RÉSUMÉLa gestion du système d'irrigation au Pakistan connait des réformes institutionnelles pour introduire la gestion participative de l'irrigation (PIM) avec la participation des agriculteurs. Cette étude a été entreprise pour examiner les impacts des réformes institutionnelles en comparant la prestation de services d'irrigation de la branche Hakra 3-R exploitée par le département de l'irrigation provincial et la branche Hakra 4-R exploitée par l'organisation des agriculteurs (FO). La présente étude est fondée sur une analyse détaillée de 18 canaux: neuf cours d'eau sur chacune des deux branches. Les enquêtes ont porté sur des paramètres tels que le taux de livraison, le rendement (RMR), le coefficient de variation spatiale (CVS), le coefficient de variation temporelle (CVT), le revenu net des agriculteurs, les productivités des terres et de l'eau. Les résultats de l'étude a révélé que la branche 4-R a une prestation de services d'irrigation relativement supérieure à celle de 3-R. Le revenu net moyen, des terres et de l'eau productivité ont été plus élevés pour la branche 4-R. Sur la base des résultats de cette étude, il est conclu que la gouvernance globale du canal d'irrigation géré FO (4-R) était meilleure que celle du canal géré par l'Etat, (3-R) mais la performance de ce dernier était également en deçà des attentes.

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In Pakistan, phosphotic fertilizer such as Diammonium phosphate (DAP) conventionally applied to wheat by broadcast method before sowing crop. This is wasteful method of fertilizer application as only 15-20% of applied phosphate is utilized by the crop. To overcome the problems of phosphorus fixation, fertilizer band placement drill (FBPD) for wheat had been developed and its performance was evaluated at farmer's fields. This drill places DAP fertilizer near the seed that is about 5 cm away and 5 cm deeper than the seed due to which phosphorus use efficiency has increased. Experiments conducted at farmer's fields showed excellent results of fertilizer band placement drill even 50% DAP was saved with 10 % excess wheat yield. In previous study s results of the fertilizer band placement drill were very encouraging as compare to farmer practice (Rabii Drill). Farmers were reluctant to adopt this fertilizer saving drill due to its heavy weight, which make it difficult to operate by commonly available 50-40 hp tractors. Keeping in view all these issues a low-cost version of fertilizer band placement drill was designed and developed with the help of local manufacturer. Over all Weight reduction (from 450 to 390 kg) and changing the drive wheel mechanism (from rear to front) for seed metering was incorporated in modified drill so that it can be easily operated by commonly available 50 hp tractor. After modification, fertilizer band placement drill was tested and compared it with zero tillage drill and rabi drill (farmers practice) by sown wheat in five different location of arid zone of Chakwal. Comparative field testing of three drills shows that FBPD gives significantly more yield as compared to zero till drill and Rabi drill. The effect of fertilizer band placement on all above-mentioned parameter was more pronounced over other two drills, when half bag of DAP was applied. The half bag DAP applied with fertilizer band placement drill gave 24.30% and 21.38% increased grain yield over zero-drill and farmers practice (Rabi Drill), respectively. Generally, the fertilizer band placement drill superseded both the drills in comparison at all sites.