scholarly journals OPTIMIZATION OF DITHIONITE BLEACHING OF HIGH YIELD BAGASSE PULP

2021 ◽  
Vol 55 (5-6) ◽  
pp. 667-673
Author(s):  
MOHAMED EL-SAKHAWY ◽  
AMAL H. ABD EL-KADER ◽  
TAMER Y. A. FAHMY ◽  
ESSAM S. ABD EL-SAYED ◽  
NESRINE F. KASSEM
Keyword(s):  
Raw Materials ◽  
Chelating Agent ◽  
Sodium Dithionite ◽  
Forest Resources ◽  
High Yield ◽  
Diethylenetriaminepentaacetic Acid ◽  
Bleaching Agent ◽  
High Brightness ◽  
Temperature Time ◽  
Bagasse Pulp

Non-wood raw materials are an essential fiber source in regions where forest resources are limited. Therefore, chemi-mechanical high-yield bagasse pulp was prepared and then bleached with a dithionite bleaching agent. One- and two-stage bleaching of the pulp was carried out by using sodium dithionite (Y) as a sole bleaching agent, or after bleaching with hydrogen peroxide to achieve high brightness for the prepared pulp. Different parameters, such as consistency, concentration, temperature, time and pH were investigated. The effect of various additives, such as diethylenetriaminepentaacetic acid (DTPA) as chelating agent or Zn compounds and hexamethylenetetramine to stabilize the bleaching solution, was studied. The effect of dissolved oxygen in liquor was also considered.

scholarly journals A Brief Review on Solvent-Free Synthesis of Zeolites

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 788
Author(s):  
Jinlin Mei ◽  
Aijun Duan ◽  
Xilong Wang
Keyword(s):  
High Efficiency ◽  
Raw Materials ◽  
Solvent Free ◽  
High Yield ◽  
Control Synthesis ◽  
Mechanical Mixing ◽  
Synthesis Mechanism ◽  
Wastewater Pollution ◽  
Low Efficiency ◽  
Solvent Free Synthesis

The traditional hydrothermal method to prepare zeolite will inevitably use a large amount of water as a solvent, which will lead to higher autogenous pressure, low efficiency, and wastewater pollution. The solvent-free method can be used to synthesize various types of zeolites by mechanical mixing, grinding, and heating of solid raw materials, which exhibits the apparent advantages of high yield, low pollution, and high efficiency. This review mainly introduces the development process of solvent-free synthesis, preparation of hierarchical zeolite, morphology control, synthesis mechanism and applications of solvent-free methods. It can be believed that solvent-free methods will become a research focus and have enormous industrial application potential.

scholarly journals Design of Low-Cost and High-Strength Titanium Alloys Using Pseudo-Spinodal Mechanism through Diffusion Couple Technology and CALPHAD

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2910
Author(s):  
Chaoyi Ding ◽  
Chun Liu ◽  
Ligang Zhang ◽  
Di Wu ◽  
Libin Liu
Keyword(s):  
Diffusion Couple ◽  
Titanium Alloys ◽  
High Throughput ◽  
Volume Fraction ◽  
Raw Materials ◽  
Low Cost ◽  
High Strength ◽  
High Yield ◽  
Α Phase ◽  
Cr System

The high cost of development and raw materials have been obstacles to the widespread use of titanium alloys. In the present study, the high-throughput experimental method of diffusion couple combined with CALPHAD calculation was used to design and prepare the low-cost and high-strength Ti-Al-Cr system titanium alloy. The results showed that ultra-fine α phase was obtained in Ti-6Al-10.9Cr alloy designed through the pseudo-spinodal mechanism, and it has a high yield strength of 1437 ± 7 MPa. Furthermore, application of the 3D strength model of Ti-6Al-xCr alloy showed that the strength of the alloy depended on the volume fraction and thickness of the α phase. The large number of α/β interfaces produced by ultra-fine α phase greatly improved the strength of the alloy but limited its ductility. Thus, we have demonstrated that the pseudo-spinodal mechanism combined with high-throughput diffusion couple technology and CALPHAD was an efficient method to design low-cost and high-strength titanium alloys.

Syntheses of a Green Organic Phosphorescence Materials and Studies on their Photoluminescent Properties

2012 ◽  
Vol 455-456 ◽  
pp. 880-883
Author(s):  
Lian Ying An ◽  
Zheng Guo Zhang ◽  
Xian Yin Zhao
Keyword(s):  
Raw Materials ◽  
Green Light ◽  
Fluorescence Spectrometry ◽  
High Brightness ◽  
Light Emitting ◽  
Spectrometry Analysis ◽  
New Synthesis ◽  
Optical Luminescence ◽  
Designed Synthesis

Using the second o-nitro aniline and benzoyl chloride as the initial raw materials, a green light-emitting materials (pbi)2Ir (acac)2 was produced utilizing a new designed synthesis plan. The complex’s structures were characterized by IR, MS, and the differential thermal analysis. The optical Luminescence Properties of the complex was studied by the fluorescence spectrometry analysis. The melt point of the product is 343°C which showed that it had thermal stability.. The fluorescence spectrometry analysis experimental results show that the Excitation and emission peaks of the organic Iridium (Ⅲ) complexes got were respectively 470.6nm and 526.21nm which showed that it belong to green high-brightness light-emitting materials. The oxidation of the intermediate products exposed in air which could cause the quality of product instability was avoided in the new synthesis plan improved.

scholarly journals Intensification of the extraction process of phenolic compounds from Acorus calamus leaves

2021 ◽  
pp. 4-10
Author(s):  
Oleksiy Andryushayev ◽  
Olena Ruban ◽  
Yuliia Maslii ◽  
Inna Rusak
Keyword(s):  
Phenolic Compounds ◽  
Raw Materials ◽  
Extraction Process ◽  
Raw Material ◽  
Acorus Calamus ◽  
Optimal Conditions ◽  
Ultrasonic Action ◽  
Different Temperatures ◽  
Method Of Extraction ◽  
Temperature Time

The aim. To determine the intensified method of extraction of phenolic compounds from Acorus calamus leaves and optimal conditions for the process. Materials and methods. In order to develop the optimal intensified method of extraction samples were prepared in different conditions of raw materials-extractant ratio, temperature, time and multiplicity. As a raw materials spectrophotometrically pre-standardized Acorus calamus leaves were used. The extraction was carried out in a hermetically sealed ultrasonic extraction reactor PEX 1 (REUS, Contes, France). As the criteria of extraction efficiency were indicators of dry residue and total amount of flavonoids determined using methods described in State Pharmacopoeia of Ukraine. The amount of flavonoids was determined spectrophotometrically on a certified device Specord 200 (Analytik Jena, Germany). Results. According to our research results it was found that ultrasonic action and addition of surfactant significantly improves the efficiency of the extraction process. The optimal conditions for the process were determined. Experimentally proved that the rational raw material-extractant ratio is 1:15. Comparative study of the extraction process with different temperatures showed that the highest amount of extractives is achieved at temperature 70 °C and 45 min of duration. The optimal extraction multiplicity is 3. Conclusions. As a result of the study, the intensified extraction method for Acorus calamus leaves – re-maceration with ultrasound – was established. The conducted researches allowed to develop the method of extraction, expedient in the conditions of the modern pharmaceutical industry.

scholarly journals Problematic of Rattan Resource Management: Conservation and Post-harvest Concerns in Bamenda Town and Its Environs

2020 ◽  
pp. 80-92
Author(s):  
Gilbert Zechia Mofor ◽  
Nadine Yemelong Temgoua ◽  
Ndamsa Dickson Thomas
Keyword(s):  
Urban Communities ◽  
Urban Areas ◽  
Raw Materials ◽  
Forest Resources ◽  
Basic Knowledge ◽  
Innovative Technologies ◽  
Post Harvest ◽  
Secondary Sources ◽  
Usage Patterns ◽  
A Chain

The use of durable forest resources in urban areas has raised the question of link between conservation and usage patterns. Population growth in Cameroon urban areas has continued to trigger constant demand for forest resources notably for rattan resources. Owing to the thriving domestic use and trade indicators, it is observed that, the furniture processors have been experiencing considerable demand of rattan products. It was pathetic to observe that, though the whole chain of rattan dependable activities have become an integral part of livelihood strategy for many urban communities, it is without any regulatory rearmament. Such scenario has until recently been ostensibly clear that in Bamenda town is an epitome for non-awareness of the exact species used, ecological attitudes, post-harvest losses, innovative technologies and trade letdown. In the context of such lack of awareness, most socioeconomic and conservation benchmarks have remained trapped in inappropriate operations. It is in this light that, Bamenda town displays a range of concerns about the rattan resources management stakes and challenges. Thus, the main objective of this paper attempts to harness suitable socioeconomic and ecological strategies to ensure sustainability with significant potential for the rattan sources to the thriving investors’ livelihood. The study therefore, explores the stakeholders’ treasure on rattan resources derivatives and perceptions on conservation and socioeconomic standing in Bamenda town, which is a heavily dealing place. The study made use of primary and secondary sources to collect necessary data. The results indicate that, they are a chain of rattan resource investors, multiples sources of raw materials and local rattan workspaces. In addition, the paper established that, there are no conservation awareness and visions, no innovative technologies, insufficient basic knowledge about self-regulatory mechanism for informal trade on a sound rattan management as well as no veritable institutional support structures to strengthen the rattan sector. Therefore, imperiling this activity into a blur future given the gaps observed in the sector. Based on these challenges, the study has proposed pertinent concerns, which have some supportive regimented policies to awareness, sustainable conservation, production and trading trends management for livelihood of the rattan dealers in Bamenda town and beyond.

scholarly journals The Effects of rural income project on silk exports and livelihood of smallholder producers in Gatsibo District, Rwanda

2021 ◽  
Author(s):  
Abiola Ogunlusi ◽  
Olanrewaju Olaniyan
Keyword(s):  
Textile Industry ◽  
Positive Impact ◽  
Raw Materials ◽  
Climatic Conditions ◽  
High Yield ◽  
Continuous Training ◽  
Cocoon Production ◽  
Income Status ◽  
The Impact ◽  
Smallholder Producers

Abstract Sericulture has been seen in Rwanda as an opportunity for increasing raw materials for the textile industry. Therefore, it has provided a new source of income, reduced unemployment and most likely to improve the livelihood status of poor sericulture smallholder producers by increasing their income earnings. The high yield in silk production has been pleasing due to the favourable climatic conditions for mulberry cultivation, sericulture has been seen as a potential tool to reduce poverty and also to generate foreign exchanges from exportation. The broad objective of this paper focuses on the impact of the livelihood status of smallholder producers in Rwanda. Purposive and simple random sampling techniques were employed in selecting 286 sericulture households’ farmers in Gatsibo district. Data for this study were analysed using descriptive statistics, inferential statistics, paired-samples t-test, cross-tabulation and chi-square test of independence. The results of this study showed clearly a significant improvement in the livelihood of the farmers. It was gathered that 82% asserted there are organized markets available for silk exportation. 77% affirmed an improvement in their income status. The average level of income per year from cocoon production among the farmers was estimated to be $ 227.59. It is of topmost priority for this program to continue because its effect has a very positive impact on the livelihood status of the beneficiaries. Farmers should be provided with continuous training, access to credits. If sustained properly it will resolve future challenges and springs more opportunities for farmers and likewise to the country through exports.

scholarly journals The Effects of rural income project on silk exports and livelihood of smallholder producers in Gatsibo District, Rwanda.

2021 ◽  
Author(s):  
Abiola Ogunlusi ◽  
Olanrewaju Olaniyan
Keyword(s):  
Textile Industry ◽  
Positive Impact ◽  
Raw Materials ◽  
Climatic Conditions ◽  
High Yield ◽  
Continuous Training ◽  
Cocoon Production ◽  
Income Status ◽  
The Impact ◽  
Smallholder Producers

Abstract Sericulture has been seen in Rwanda as an opportunity for increasing raw materials for the textile industry. Therefore, it has provided a new source of income, reduced unemployment and most likely to improve the livelihood status of poor sericulture smallholder producers by increasing their income earnings. The high yield in silk production has been pleasing due to the favourable climatic conditions for mulberry cultivation, sericulture has been seen as a potential tool to reduce poverty and also to generate foreign exchanges from exportation. The broad objective of this paper focuses on the impact of the livelihood status of smallholder producers in Rwanda. Purposive and simple random sampling techniques were employed in selecting 286 sericulture households’ farmers in Gatsibo district. Data for this study were analysed using descriptive statistics, inferential statistics, paired-samples t-test, cross-tabulation and chi-square test of independence. The results of this study showed clearly a significant improvement in the livelihood of the farmers. It was gathered that 82% asserted there are organized markets available for silk exportation. 77% affirmed an improvement in their income status. The average level of income per year from cocoon production among the farmers was estimated to be $227.59. It is of topmost priority for this program to continue because its effect has a very positive impact on the livelihood status of the beneficiaries. Farmers should be provided with continuous training, access to credits. If sustained properly it will resolve future challenges and springs more opportunities for farmers and likewise to the country through exports.

FOOD FOREST RESOURCES OF THE FAR EASTERN REGION

2020 ◽  
pp. 405-407
Author(s):  
N. Stepakova
Keyword(s):  
Industrial Production ◽  
Raw Materials ◽  
Federal District ◽  
Forest Resources ◽  
Eastern Region ◽  
Medicinal Products ◽  
Far Eastern

The paper presents an overview of food forest resources of the Far Eastern Federal District: wild berry raw materials, nut and fruit raw materials and medicinal products, the main directions of its application in industrial production. Volumes of food forest resources by species are shown.

Preparation of Delafossite CuYO2 by Metal-citric Acid Complex Decomposition Method

2009 ◽  
Vol 1166 ◽  
Author(s):  
Keishi Nishio ◽  
Tomomi Okada ◽  
Naoto Kikuchi ◽  
Satoshi Mikusu ◽  
Tsutomu Iida ◽  
...  
Keyword(s):  
Thermal Decomposition ◽  
Citric Acid ◽  
Single Phase ◽  
Raw Materials ◽  
Chelating Agent ◽  
Amorphous Powder ◽  
Heat Treating ◽  
Acid Complex ◽  
Synthesis Conditions ◽  
Starting Solution

AbstractDelafossite CuYO2 and Ca doped CuYO2 were prepared by thermal decomposition of a metal-citric acid complex. The starting solution consisted of Cu acetate, Y acetate and Ca acetate as the raw materials. Citric acid was used as the chelating agent, and acetic acid and distilled water were mixed as a solvent. The starting solutions were heated at 723 K for 5 h after drying at 353 K. The obtained powders were amorphous and single phase of orthorhombic Cu2Y2O5 was obtained by heat-treated the amorphous powder at a temperature range between 1073 and 1373 K for 3 h in air. Furthermore, Heat-treating the obtained orthorhombic Cu2Y2O5 at above 1373 K in air caused it to decompose into Y2O3, CuO and Cu2O. On the other hand, the sample powder prepared from a starting solution without citric acid, i.e., single phase of orthorhombic Cu2Y2O5 could not be obtained under the same synthesis conditions as that for a solution with citric acid. We were able to obtain delafossite CuYO2 and Ca doped CuYO2 from orthorhombic Cu2Y2O5 under a low O2 pressure atmosphere at above 1223 K. The obtained delafossite CuYO2 composed hexagonal and rhombohedral phases. The color of the CuYO2 powder was light brown and that of Ca-doped CuYO2 was light green. Diffraction peaks in the XRD pattern were slightly shifted by doping Ca for CuYO2, and these peaks shifted toward to a high diffraction angle with an increasing amount of doped Ca. From these results, we concluded that Ca doped delafossite CuYO2 could be obtained by thermal decomposition of a metal-citric acid complex.

SiC Platelets Synthesized by Powder-Heating Technique

2007 ◽  
Vol 336-338 ◽  
pp. 939-941
Author(s):  
Yong Qiang Meng ◽  
Zhi Min Bai ◽  
Chang Hong Dai ◽  
Bao Bao Zhang
Keyword(s):  
Silicon Carbide ◽  
Reaction Time ◽  
Carbon Black ◽  
Raw Materials ◽  
Low Cost ◽  
Average Diameter ◽  
New Method ◽  
Conventional Heating ◽  
High Yield ◽  
Sio2 Powder

A new method for producing silicon carbide platelets with low cost and high yield was introduced. The silicon carbide platelets were synthesized by powder-heating techniques with carbon black and SiO2 powder as raw materials and CoCl2 as catalyst. The starting mixtures were heated at a temperature in the range of 1800-2000°C for the duration of about 2-4h to produce substantially completely unagglomerated silicon carbide platelets with a thickness of 5-20μm and the average diameter of 50-200μm. Compared to the conventional heating, the powder-heating technique is advantageous of less investment on equipment, easy to manufacture and convenient to operate. Furthermore, it is very suitable for realizing the scaled production because of the lower synthesizing temperature, shorter reaction time and greater output.

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