جستجوی مقالات مرتبط با کلیدواژه « brightness » در نشریات گروه « کشاورزی »

In this research, the effect of sodium peroxide and sodium hypochlorite on the chemical-mechanical pulp bleaching (CMP) has been investigated. For this purpose, unbleached CMP pulp was produced from Mazandaran wood and paper mill, and bleaching with hydrogen peroxide and sodium hypochlorite was carried out in two levels of 3 and 4%, during both 60 and 90 minutes in 70°C at 8% consistency. In each treatment, 30 grams of pulp with hydrogen peroxide, sodium silicate, DTPA, sodium hydroxide and sodium hypochlorite for bleaching were prepared. In the following 60 gr/m2 hand sheets were prepared and the optical properties of hand sheets were measured and analyzed based on TAPPI.The results obtained from the review of optical properties of handsheets show that by increasing the bleaching time and the level of chemicals the optical properties was improved. So that the highest brightness and minimum yellowness were observed in the 4% and 90 minutes in bleaching whit hydrogen peroxide. the lowest opacity in the control sample. Resistance properties such as tensile, burst and tear strength of bleached paper were also increased.

presented researches during recent years, showed that using biotechnological base methods, specially using industrial enzymes for processing of waste papers is considered as a suitable approach to improve optical and mechanical properties of recycled papers. In this research deinking of offset printed waste newspapers using lipase enzyme was studied.
In this research enzymatic deinking of the recycled newspapers was investigated using lipase at three-time level as 60, 120 and 180 min, and three level of enzyme use as 3, 6 and 9 U/g O.D pulp at neutral pH value. Washing method was used to remove ink particles.
Comparison of the optical, physical and strength properties of the made handsheets showed that enzymatically deinking could enforce the strength properties (tear and burst strengths) in the related handsheets compared to those of the control sample. In addition, lipase-deinked pulps showed higher brightness and lower yellowness than the control sample. However, opacity of enzymatic treated pulps decreased with prolongation of treatment time compared to the control sample.
It can be generally concluded that enzymatic deinking using lipase is an appropriate method to improve the optical and strength properties of offset printed waste newsprints. It seems that increasing the amount of enzyme treatment in more than 9 units of enzyme per gram of dry pulp had a significant reduction in the opacity content of dry pulp compared to the control sample and Increasing the treatment time will also be effective in this reduction.

IntroductionRoselle or Hibiscus sabdariffa L. is an annual herbaceous plant which grows properly in tropical and sub-tropical areas. Sepals are the main commercial part of roselle with unique brilliant red colour and flavor which are containing many nutritional compounds such as anthocyanin and vitamin C. Accordingly, sepals commonly are used in food industries for production of beverages, juices, jams and syrup (Duangmal et al., 2008; Sanjari-Mijani et al. 2015). Therefore, production of high quality sepals via the good agronomic practices is an important topic in roselle cultivation. So far, the effect of irrigation management (Rahbarian et al. 2011), mycorrhizal inoculation (Sembok et al. 2015) and humic acid application (Sanjari-Mijani et al. 2015) on some qualitative and quantitative indices of roselle has been evaluated in some studies. However, the impacts of mentioned factors on colour characteristics of dried sepals including hunter color values, colour intensity and hue angle has not been studied. Therefore, due to the impact of colour on marketability and drug quality, the aim of this study was to evaluate the effect of water availability, mycorrhizal symbiosis and humic acid application on colour indices of dried sepals in roselle.
Materials and methodsIn this experiment, the influence of irrigation regimes [irrigation after 100 mm (normal irrigation) and 200 mm (deficit irrigation) pan evaporation], humic acid application (0 and 4 kg.ha-1) and mycorrhizal inoculation (Glomus versiforme, Glomus intraradices and control) were studied on colour characteristic of roselle sepals. For this purpose an experiment at the form of split-split-plot layout based on a randomized complete block design with three replications was carried out during 2015-16 at research field of Sarayan Faculty of Agriculture (33ºN, 58ºE, 1450 masl, annual precipitation of 150 mm and annual temperature of 17ºC.) in east part of Iran. Seed planting was done on 20 April using Sistan & Balochestan ecotype with 10×50 cm intra and inter-rows distances. Humic acid was used in irrigation water two times during vegetative growth of roselle i.e. 15 and 35 days after emergence. All plots were irrigated similarly two times during the first week after seed sowing and then irrigation treatments were exerted separately in each plot until November 15 when irrigation was stopped. After that, calyces belonged to each treatment were harvested and dried separately in ambient temperature and shade condition of laboratory and then were used for colour analysis. Color of dried sepals was evaluated using a colorimeter (TES 135, Shenzhen Youfu Tools Co., Ltd. - TAIWAN). Results were expressed as Hunter color values (l*, a* and b*). L is the brightness ranging from 0 (black) to 100 (white). The value a* is the redness ranging from negative values for green to positive values for red. The value b* is the yellowness ranging from negative values for blue and positive values for yellow. In addition, color intensity (Chroma), hue angle and browning index were calculated using equations presented by Duangmal et al., (2008). Finally, data were statistically analyzed using SAS 9.1 and means were compared by duncan test at 5% level of probability
Results and discussionResults showed that the effect of experimental factors was significant on most of colour indices in roselle calyces. Droughts stress reduced a* value, hue angle and chroma by 22, 53 and 15% respectively. Humic acid application also reduced the amount of hue by 63% while increased the b/a by 25%. Both mycorrhizal species enhanced the hue index by 66% compared with control treatment. Results of interaction effects revealed that the highest amount of b/a (0.19) was obtained at droughts stress × humic application × mycorrhizal inoculation, while its lowest value (0.02) observed at no stress ×no-humic ×no-inoculation treatment. In addition, the maximum amount of hue (215 º) was obtained at no water stress × humic application × mycorrhizal inoculation using Glomus versiforme. The treatment of no stress × no humic × mycorrhizal symbiosis produced the maximum amount of redness index. Moreover, a significant correlation was observed between a* with chroma (.64**) and browning index (-0.71**) as well as between hue and redness index (.00**). Overall, colour quality of roselle sepals was more suitable under appropriate water supply. In addition, mycorrhizal inoculation partially reduced the negative impacts of droughts stress on calyxes colour characteristics. The reducing effect of sever water stress and the positive role of mycorrhizal inoculation on growth, yield and quality of roselle has been previously reported by other researchers (Rahbarian et al., 2011; Sembok et al. 2015). It has been reported that red anthocyanins in sepals of roselle are responsible of its brilliant red colour (Duangmal et al., 2008). Our qualitative analysis revealed that the amount of anthocyanins in drought stress condition was 12% lower than no stress treatment. Furthermore, mycorrhizal symbiosis using G. intraradices and Glomus versiforme improved the amount of this index by 20 and 5%, respectively (data are not presented). These observations are in accordance with the trend of redness change in dried sepals. Accordingly, it seems that more redness and a*, hue angle in no stress and inoculation treatments is because of more anthocyanin content in related plants. This finding is also understandable from positive regression relation between redness index and sepals anthocyanin content.
ConclusionsConsidering to colour characteristics and regards to yield and qualitative indices such as anthocyanin and vitamin c content (data are not presented), it seems that appropriate water availability and use of mycorrhizal symbiosis are two good strategies for roselle production.

Background and goals: This research changed into achieved with the intention of manufacturing dissolving pulp or alpha-cellulose from bagasse. Alpha-cellulose is generally used for making cellulose derivatives with advantage of being soluble in commonplace solvents in recognize to cellulose. Dissolving pulps have high alpha-cellulose and brightness, but very low hemicelluloses, ash, and extractives, with uniform molecular weight distribution.
Substances and Bagasse chips were pretreated beneath slight acidic situation the use of acetic acid at most temperature of a hundred 165 ºC, to obtain yield loss stages of approximately 20 and 30 percent in pre-extraction level. Bleachable pulps at kappa wide variety decrease than 12 had been created from each the pre-extracted samples, the usage of soda-AQ pulping technique at most cooking temperature of a hundred 165 ºC. The pulp samples produced under optimum situations, have been bleached by chlorine free bleaching (ECF) with AD0EpD1P bleaching sequence. The properties have been decided on the basis of policies TAPPI. In the end, a statistical evaluation of the effects of exams finished on dissolving pulps created from SPSS software program and t-test two samples become used. in this look at, dissolving pulp carries numerous alpha-cellulose from depithed Bagasse with acid pre-extraction and the soda-AQ pulping procedure turned into prepared. While that within the acid pre-extraction yield loss improved from 20 to 30, the alpha cellulose production increased but the degree of polymerization declined. In produce dissolving pulp, in addition lignin, hemicelluloses are also undesirable impurities, so the more material will be removed from the purity cellulose pulp increases, but with increasing destruction of the hemicellulose in the pre-extraction, may be cellulose chain additionally damaged, although alpha-cellulose to increase the degree of polymerization to be associated with high drop. Bagasse dissolving pulp having ninety two percentage alpha-cellulose with DP of 870, can also have restrained packages in making derivatives such as cellulose acetate and cellulose nitrates, however it is able to be used to supply decrease demand products such as viscose rayon and carboxymethyl cellulose. But, the yield and ash dissolving pulp were first-class. The outcomes of this studies evaluation with other research inside the discipline of dissolving pulp manufacturing and additionally considering that the bagasse produced in massive quantities inside the south of the united states, imparting a number of the pulp or alpha cellulose the used inside the manufacture of viscose rayon, as a minimum, can be planned based on bagasse as uncooked cloth.

Increasing use of wood products accompanying with resource constraint has revealed the importance of nonwood based material. In this study, pulping and papermaking potential of three varieties of weeds including Xanthium spinosum, Carthamus tinctorius and Cyperus papyrus have been considered. At first, chemical components of the samples i.e. cellulose, lignin and extractives have been measured following TAPPI standard test methods. Afterwards, pulping process based as soda and Kraft has been carried out and the pulp properties i.e. screen yield and reject, kappa number, caliper, bust index, tear index, brightness have been considered. According to the results, the amount cellulose, lignin and extractives have been measured for the Xanthium spinosum %38.15, %13.5 and 4.72, respectively. Theses parameters have been estimated about %38.25, %10.3 and % 2.95 for Carthamus tinctorius and %38.8, %19.2 and 4.4 in case of papyrus. The yield of soda and Kraft pulp of the papyrus was more than Xanthium spinosum and Carthamus tinctorius. Among all treatments, the highest screen yield related to soda pulping of Cyperus papyrus by %39.8 which has been obtained by 175 centigrade as a maximum temperature, L/W: 6/1, active alkaline: %30 and 90 minutes as the time at temperature. The lowest and highest amounts of the tear index were related to soda pulp sample of the Carthamus tinctorius and Kraft pulp sample of Xanthium spinosum by 2.49 and 8.1, respectively. In addition, the lowest and highest amounts of the bursting index were related to soda pulp sample of the Cyperus papyrus and Kraft pulp sample of Xanthium spinosum by 0.61and 2.48, respectively. Meanwhile, soda pulp sample of the Cyperus papyrus showed the highest amount of brightness with %45 ISO.

The old newsprint, as an important grade of waste papers, usually has been produced from chemicalmechanical pulp (CMP). Although the effect of paper aging on different properties of recycled pulp has been investigated from long time ago; but, few studies have been observed about the effect of this phenomenon on recycling of CMP paper. In this study, accelerated aging was applied on Hardwood CMP newspaper by 2 levels of temperature (50 and 100˚c) and 2 levels of time (24 and 48 hours). Results showed that accelerated aging applying 100˚c in 24 and 48 hours (about half of a decade and more) impose an intense reduction tensile strength, burst strength and tear strength indices as well as folding endurance strength of recycled pulp. Also, accelerated aging in 50˚c for 24 and 48 hours (about six months until one year) did not show any special effect on mentioned mechanical properties. Moreover, thermal accelerated aging didn’t have any significant effect on brightness of deinked CMP pulp. In general, it can be concluded that CMP waste papers less than one year old can preserve or even upgrade their mechanical properties after recycling, but aging more than half of a year will have detrimental effect on these properties

Some extractive compounds from wood, adhesives which are difficult to remove during pulp washing and cause adhesive residues on process equipment. In preparing pulp from hardwoods, These compounds are the source of numerous problems such as the formation of sticky materials, impurities remain in the paper pulp and paper break in paper machine. In addition, remain these compounds on paper caused problems such as creation dark spots and paper fibers stick on the cylinder surface, paper breaks and clogging with and felt. Also the extractives may react with chemical bleaching and produce changed and oxidized products. Changed extractives are causing pitch problem and have a negative impact on pulp brightness. In this study, the effect of hot water and alkali pretreatment on bleach ability of hornbeam CMP pulp was studied.
Methods and materials:Hornbeam wood chips prepared from Mazandaran wood and paper mill. Treated with hot water and alkali done in three levels of 0.5, 2 and 3.5 percent with the aim of removing the extractives before pulping process and then prepared pulp from control and pre-treated wood chips with the same conditions and CMP process and bleached with hydrogen peroxide. Handmade paper produced from the resulting pulp and papers optical properties before and after bleaching and strength properties of produced papers before bleaching was examined.
The sample pre-treated with stable temperature and time, the mass loss during pretreated with hot water is less than pre-treated with alkali and in the alkali treatment, the mass loss increased with increasing alkali percent. In both pretreated cases, pre treated hornbeam chips pulp yield is more than control sample. The refining rounds and energy consumption of paper pulp produced from alkali pretreated chips is more than pulp from wood chips pre-treated with hot water. The brightness of hot water and alkali pre-treated samples before and after bleaching Increased compared to the control sample. During alkali pre-treated, with increasing the percentage of alkaline, pre-treated samples also showed an increase brightness. Before bleaching, opacity of sample pre-treated with hot water had low increase and in general, significant differences between the samples treated with hot water and control at the level of 5% was no observed. The sample pre-treated with stable temperature and time, the hornbeam tensile index increased. Pretreatment with alkali also increases the tensile index. Burst index increased by hot water pretreatment. Pre-treated with alkali also increase burst index. Samples pre-treated with hot water and alkali showed that tear index increased and rised with the alkaline percentage increase.
Hornbeam wood chips pre-treated with hot water and alkali caused wood chips mass reduce and increase CMP wood pulp yield compared to the control. Brightness of pretreatment samples before and after bleaching increased than the control sample. Opacity in the samples pretreated with hot water increased and decreased during the treatment with alkaline solution. In those pre-treated with hot water and alkaline solution than the control sample, hornbeam paper pulp tear index increased but in burst index and tear strength was no difference significant.

With considering that in chemical-mechanical pulp (CMP) production process , the wood chips washing pre-treatment is important , so this research was conducted to investigate the effect of pre-treatment washing of populous deltoids wood chips on CMP Optical(brightness and opacity) and Strength(tensile and burst indexes) properties. Pre-treatment was accomplished with pure hot water and alkaline solutions (NaOH) at three levels of 0.5, 2 and 3.5 percent too. Pre-treated populous deltoids wood chips and control (chips without washing) were converted to pulp by CMP process. The results of this research indicated that the pretreatment of populous deltoids wood chips with hot water and also alkaline solutions caused wood chips mass and using of these treated chips for pulping caused pulp yield and brightness increscent, pulp strength reduction and also energy consumption increscent. . Removing of some part of chips hemicellulos have negative effect on the pulp refinability and cause pulp strength reduction.

The present study was carried out aiming to investigate The effect of using Deinked Mixed Office Waste Paper (MOW) on the properties of Alkaline Proxide Mechanical Pulp (APMP) from cotton stalk. In order to APMP pulps was prepared using chelating agents such as Na2SiO3 and DTPA (control sample) and without these agents in two-stage pulping with L/W ratio 6:1(ml/g), 20 minutes and 70 0C for first stage, 60 minutes and 75 0C for second stage. Also, pulp was prepared from mixed office waste paper, which were deinked with conventional flotation and then separately refined up to about 300 ( CSF,ml ) freeness. The handsheets were made from control sample pulps, APMP without chelating agents, MOW deinked pulp and mixing 10%, 20% this pulp with control APMP. Physical and mechanical properties were determined using TAPPI standard methods. Deinked pulp of MOW had the maximum values of density, brightness, strength properties and APMP pulp without chelating agents had the minimum values . Among mixed pulps, APMP pulp having 20% deinked MOW pulp had the maximum value of density, brightness, burst index and tear index.

The pulp color reversion, at the end of bleaching, and non-totally consumption of peroxide are two problems in high-yield pulp bleaching. In this study, the effect of TAED, at the end phase of bleaching, on process and pulp properties was investigated. Hardwoods chemi-mechanical pulp (CMP) (85% yield), was bleached by mono-stage alkali peroxide process. Treatments comprising three different charges of peroxide (1.5, 2 and 3%) and alkali (sodium hydroxide) (1.12, 1.5 and 2.25) with and without using TAED at the end phase of bleaching i.e. the last 10 minutes. The results indicated that, the pulp brightness and bleaching selectivity increased by chemical charge rising, but with decreasing slope procedure. The chemical charge rising led to an increase in residual peroxide and filtrate COD load. TAED using, through reduction of alkali darkening reaction, caused to improve the brightness and selectivity, and reduce the COD load. Residual peroxide amounts of treatments, which have TAED treatment, were significantly decreased.

This research was performed to evaluate the potential of acid pre-hydrolysis soda-AQ process for the production of dissolving pulp including high α-cellulose content from Populus deltoides. To achieve the aim, a pre-hydrolysis liquor containing 0.06% acid sulfuric, soda-AQ pulping, and OD0ED1 bleaching sequence were used. The results show that using at least 0.40 kappa factor at D0 stage was necessary to gain access a high quality dissolving pulp including characteristics like having brightness level and α-cellulose content higher than 86% and 98%, respectively. A kappa reduction of 40.3% was achieved by performing a single stage oxygen delignification after soda-AQ pulping to drop kappa number of pulp from 14.1 to 8.4 prior to entrancing the pulp into the final bleaching stage. The results illustrated that producing acid pre-hydrolyzed soda-AQ dissolving pulp including high α-cellulose content and brightness, and even viscosity is completely feasible through controlling and optimizing the acid pre-hydrolysis, pulping, oxygen delignification stages, and D0ED1 bleaching sequence.

In this study the effect of different values of peroxide in three levels 3%، 4%، 5% and sodium hydroxide in two levels 2%، 3%، on bleaching of tobacco stalks (Nicotiana tabacum L. ''PVH 19'') soda pulp was investigated. Tobacco stalks were soda pulped using 22% alkali in 170°C for 100 minutes. Produced pulp had 37. 1 % yield and kappa number 62. Bleaching process included two stages: chelating and alkali peroxide bleaching. Results indicated that brightness increased and kappa number decreased by increasing sodium hydroxide and peroxide Hydrogen level. The data related to 3% caustic soda and 5% peroxide treatment without chelating stage، indicated that initial chelating stage significantly affected on the brightness، kappa number and yield of the bleached pulp، and this treatment had the lowest brightness and the highest kappa number and yield among all treatments. Finally، 3% caustic soda-5% peroxide treatment with initial chelating stage had the highest brightness (44. 50%) and the lowest yield (83. 20%)، was selected as the best treatment.

 In this study, the effect of different values of peroxide in three levels 3%, 4%, 5% and sodium hydroxide in two levels 2%, 3%, on bleaching of tobacco stalks (Nicotiana tabacum L.’PVH 19') soda pulp was investigated. Tobacco stalks were soda pulped using 22% alkali at 170°C for 100 min. Produced pulp had 36.2% yield and kappa number of 77. Bleaching process was included two stages of chelating and alkali peroxide bleaching. Results indicated that brightness increased and kappa number decreased by increasing sodium hydroxide and hydrogen peroxide level. The data related to 3% caustic soda and 5% peroxide treatment without chelating stage indicated that initial chelating stage significantly affected on the brightness, kappa number and yield of the bleached pulp, and this treatment had the lowest brightness and the highest kappa number and yield among the treatments. Finally, 3% caustic soda-5% peroxide treatment with initial chelating stage had the highest brightness (40.99%) and the lowest yield (40.10%), was selected as the best treatment.

This research was carried out in order to comparatively investigate the hornbeam kraft، soda and soda-urea papermaking properties. The selected treatment in kraft process had an average yield of 44. 43% and kappa number of 23. 75. In soda process the selected treatment had an average yield of 38. 75% and kappa number of 19. 28. In soda-urea process، the selected treatments had an average yield of 39. 85، 40. 1، 40. 5، 39. 8 and 40. 61 and kappa number of 21. 21، 22. 33، 22. 66، 25. 28 and 26. 85. After refining the selected pulp to reach the freeness of 400±25 ml CSF، 60 g/m2 handsheets were made and physical، mechanical and optical properties were measured. Results showed that kraft pulps had higher yield and better refinability than soda and soda-urea pulps. Papers made from kraft process had higher strength properties than those made of soda and soda-urea process. With addition of urea، yield and kappa number of pulps increased. The highest improvement in tensile index، breaking length and tear index was achieved with addition of 3% urea and the highest improvement in burst index was achieved with adding 4% urea. Results of brightness measurements showed that papers from kraft and soda processes had the lowest and highest brightness degree respectively. With the addition of urea، brightness of papers decreased.

Unbleached chemi-mechanical pulp of 85% pulp yield and produced from hornbeam، beech and populus woods respectively by 3:1: 1 ratio، was used for peroxide bleaching. Two bleaching systems، alkali peroxide (conventional bleaching) and activated peroxide by TAED activator، were used for pulp bleaching. Bleaching treatments included different percentages of hydrogen peroxide and caustic soda consumption. In this research، the hydrogen peroxide consumption rate، pulp yield، process selectivity، bleached pulp brightness and bleaching effluent pollution load (COD) were investigated. Results showed that، brightness values were increased by bleach chemicals charge rising، in both bleaching systems، but the increasing trend was downward. Also، pulp yield was decreased by increase of chemical charges، but residual peroxide was raised. The activated peroxide process compare to conventional process had lower efficiency and brightness improvement values of pulp were less than those of alkali peroxide process. But pulp yield and effluent pollution load was less by activated peroxide bleaching.

Flotation deinking is the prominent technology for ink removal from waste paper. In this study, flotation deinking was carried out applying two levels of sodium hydroxide and five levels of hydrogen peroxide on a mixture of waste papers consisting of: 30, 30 and 40 weight percent OMG, ONP and MOW, respectively. The deinking efficiency was evaluated based on brightness, yellowness and dirt count of hand sheets. The results showed that increasing hydrogen peroxide dosage can increase hand sheets brightness, however, at higher hydrogen peroxide levels, the brightness was reduced probably due to the presence of more NaOH and the limitation of hydro peroxide efficiency for chromophore elimination. Optimal ratio of H2O2/NaOH, significantly increase the efficiency of deinking at lower alkali usage. This research showed that higher deinking efficiency may not be necessarily reached applying more chemicals, but optimal chemicals ratio plays an important role in deinking efficiency.

Preparation and pre-treatment of raw material influences the pulp production time and color elimination. Pulp consistency during the treatment also influences the color reaction. In the preparation of the APMP pulp, bagasse was pretreated by either boiling water, 1% NaOH as well as 1% NaOH + 1% H2O2. The liquor to bagasse ratio, treatment time and temperature of alkaline peroxide treatment were constant as 10:1, 30 min, and 70 C respectively. The treatment duration was determined so that at least five percent of the initial hydrogen peroxide remained at the end of chemical treatment. Characteristics of hand sheets were determined according to the TAPPI standard. The results showed that, the duration of the treatment for pulp consistency of 10, 15 and 20% was 50, 30 and 10 minute, for sample pretreated with boiling water and 290, 230 and 170 minute for the sample pretreated with 1% NaOH + 1% H2O2. The highest brightness of the paper reached with bagasse pretreated in boiling water at 20 % consistency.

In this research, the recycling of chemical waste paper has been taken into consideretion.To produce printing paper, the effect of various combinations of deinked pulp with CMP pulp has studied. Deinking results showed that, besides of the chemicals effect, temperature and repulping time directly affect the brightness of deinked pulp so that when the temperature or repulping time or both go up, the brightness of deinking pulp goes up too. Test results of deinked pulps mixed with CMP pulp indicated that by adding deinked chemical pulp, with the percentage of 10, 20, and 30 to CMP pulp, optical and physical features and also mechanical strengths of paper improve. From optical and physical features and also mechanical strengths point of view, the best circumstances to combine deinked chemical pulp with CMP pulp and long-fiber pulp included 60% CMP Pulp, 30% Deinked Pulp, 10% Long-fiber Pulp. It can be suggested that %30 deinked pulp can be used to produce printing paper. Also, optimum Deinking variables were %2 NaOH (on the oven dry pulp), repulping time 10 minute and repulping temperature 65°c.

Effect of surfactants and cellulose enzyme on deinking mixed office waste paper was studied. To that end, a combination of waste paper accounting for 60% printing paper and 40% copy paper was applied. Then, samples of paper pulp were deinked using four types of cellulose, Surfactant and sodium silicate. The types and the proportion of the chemicals used in the study are as follows: a) Surfactant, b) Cellulase, 0% and 0/6 % were added based on the weight of paper pulp together with a surfactant. c) Sodium silicate with the fix amount of 0/3% of the weight of the paper pulp was used in the process. Different samples of paper pulp influenced by 24 compounds comprising enzymes and chemicals were deinked and the efficiency of the materials was calculated after the process. Following that, all the paper pulp samples were turned into hand-made papers and then indices such as brightness, dirt (quality and quantity of dirt) were studied. The results showed that the type of surfactant and cellulose enzyme affect brightness, dirt index and deinking efficiency.Maximum brightness was with nonyl phenol ethoxylate and fatty alcohol ethoxylate without cellulose enzyme.Minimum dirt index was with nonyl phenol ethoxylate and cellulose enzyme.Also, using nonyl phenol ethoxylate and fatty alcohol ethoxylate result in maximum deinking efficiency.

Variations in theaflavin and thearubigin content during fermentation and the effects of these variations on brightness and total color in black tea were evaluated at the Tea Research Center in Lahijan in the year 2004.  Percentages of theaflavin (TF), thearubigin (TR), total color and brightness were determined in two clones 100 and in the natural Chinese hybrid during flushing in the months of June, August and October and different fermentation time (30, 60, 90, 120 and 150 minutes). It is evident from the results obtained that apart from genetic differences in the clones under study, changes in climatic conditions during different periods of flushing and fermentation time can to a great extent influence the amount of TF, TR, total color and brightness in black tea. Results obtained also indicated significant interacting effects of clones, different flushing and fermentation times on the quality-determining characteristics of black tea. No significant correlations were found between TR and brightness however, significant correlations were found between other characteristics studied at the 1% probability level. On the basis of regression analysis with fermentation time (independent variable) and each of the characteristics studied (dependent variable), linear relationships were detected between fermentation time and brightness and TF content. Multi-variable regression analysis between brightness (dependent variable) and TF and TR (independent variables) showed that more than 56% of variations in brightness in black tea was related to TF and TR. Also multi-variable regression analysis between total color (dependent variable) and TF and TR (independent variable) indicated that more than 43% of variations in total color in black tea can be attributed to TF and TR percentages