amin gharanjik

Due to the hydrophilic nature of cellulose, nanofibrillated cellulose (NFC) is supplied in low solid content and high viscosity. As a cost saving strategy, increasing the possible highest solid content is preferred, which is hardly feasible owing to the irreversible hydrogen bonding formation during drying. This phenomenon known as Hornification prevents the cellulose nanofibrils to be readily dispersed in water after being dried. This research assessed an environmentally friendly procedure for the production of water-dispersible nanofibrillated cellulose powder based on carboxymethyl cellulose (CMC) absorption.

The absorption of varying amounts of CMC (0, 20 and 40 ml to constant 100 ml NFC) on cellulose nanofibrils in different temperatures of 22 °C (ambient) and 121 °C (autoclave) was investigated using conductometric titration. As the innovative part of the project, hydrodynamic properties of the dispersed NFC suspension including viscosity, turbidity, hydrodynamic specific volume, and water uptake were explored. Besides, the size of powder particles was probed by Dynamic Light Scattering (DLS).

The results indicated that in the highest addition level of CMC (40 ml) and autoclaving at 121 °C for 25 min, the highest absorption was observed, which yielded maximum results in all hydrodynamic properties compared to the control and other treated samples. On the contrary, data recorded for DLS signified that Poly Dispersity Index and the hydrodynamic diameter of the treated samples were bigger than untreated NFC, which was ascribed to the aggregation and agglomeration of cellulose particles in aqueous media.

Based on the method presented in this research, NFC powders with suitable dispersibility were obtained after oven-drying. It is concluded that the addition of adequate CMC to NFC results in increased dispersion and waster absorption capacity. The achievements of this novel method facilitates the production, handling, and storage of NFC in industrial applications.

Plants show different morphological and phonological responses to ecological conditions within their tolerable range,which are in fact part of their heredity. These changes have a key role in species survival and ecosystems sustainability. Agricultural ecosystems are very fragiledue to the severe limitations of genetic diversity and biodiversity. In an agro- ecological approach, unlike current agriculture, careful consideration of the livelihood stages and other living organisms inthe ecosystem is of interest, and so it is attempted to manage productionas well as the optimal use of agricultural inputs.

In order to study the phonological changes in four bread wheat genotypes (Gonbad, Karim, Koohdasht, Morvarid), at different levels of urea fertilizer application (0, 66, 200 kg/ha), a factorial experiment was conducted in a randomized complete block design with three replications in two crop years of 2014 and 2015 at Agricultural ResearchStation ofGonbad-e-kavoos.

The results of this study showed that the length of vegetative and reproductive stages in these two years are different, and the effect of urea content on these stages is not the same in different ecological conditions. Therefore, it was concluded that under different temperature and humidity conditions. it is possible to apply fertilizer management, without having a significant effect on the length of the phonological periods.Observations of this experiment showed that the stalking stage is more stable compared to the previous steps, so that the length of this stage was only 0.63 day in two years, and changes in different levels of fertilizer application did not show any significant difference in two years. It seems that the length of this period is lessinfluenced by environmental factors than the other stages of wheat growth and in other words. it is expected to have a higher inheritance. Changes in the pregnancy stage are also relatively similar to the stalking stage. Even though the consumption of 200 kg/ha urea fertilizer slightly increased the change of the slope, in such a way that 68% slope the increase of the span of the period from the treatment until 66 kg/ha, urea fertilizer is changed into 111.9%, but the amount of this increase is only 0.75 day.It can be concluded that although the length of this stage of plant growth is
more affected by environmental factors over the pregnancy stage, in general, the amount of this impact is not high. Observations of this study showed that the studied wheat cultivars (whether they are introduced for dry conditions or supplementary irrigation) during the course of their growth reached the stages of emergence of spike, flowering, and seedling 7.5 to 8.5
days later in the second year (pluvious) than the first year (lower rainfall). So that the difference between these two years for the emergence of the spike on average was 8.33 day, for flowering stage 7.72 day, and for the processing stage 7.56 day. Changes in fertilizer use in these three steps were similar in both years.

This study is important in management and controlling the population of non-cultivated plant species, pathogens (fungi and bacteria), insects and other species in the amount and sustainability of crop production.