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The paper is focused on investigation of the nature and size of cellulose fibers in the structure of stabilizing additives for stone-mastic asphalt concrete, as well as on determination of fibers retention capacity based on their geometric parameters. To obtain the results a scanning electron microscope JSM-6510LV was used, with the help of which 15 to 20 photomicrographs were obtained. It was found out that in all inspected samples of stabilizing additives over 80% of pulp and paper fibers have a band structure with filaments from 0.56 to 1.4 micrometer in length. The fiber thickness in all cases slightly varies within the range of 0.008 to 0.021 micrometer. For a more detailed analysis of the additives the X-ray microanalysis was carried out. The results showed that in all cases the component distribution of the chemical elements present in the additive is inhomogeneous and has two fundamental differences in the oxygen (O) and carbon (C) content. ARMIDON additives contain more than 79% carbon (C) and just 6-13% oxygen (O). VIATOP 66 and SD-1 additives contain up to 61% carbon (C) and up to 48% oxygen (O). Tests to determine the runoff of the organic binder showed that additives with cellulose fiber filaments up to 0.6 micrometers in length hold bitumen worse than additives with cellulose fiber filaments 1.4 micrometers in length.The paper is focused on investigation of the nature and size of cellulose fibers in the structure of stabilizing additives for stone-mastic asphalt concrete, as well as on determination of fibers retention capacity based on their geometric parameters. To obtain the results a scanning electron microscope JSM-6510LV was used, with the help of which 15 to 20 photomicrographs were obtained. It was found out that in all inspected samples of stabilizing additives over 80% of pulp and paper fibers have a band structure with filaments from 0.56 to 1.4 micrometer in length. The fiber thickness in all cases slightly varies within the range of 0.008 to 0.021 micrometer. For a more detailed analysis of the additives the X-ray microanalysis was carried out. The results showed that in all cases the component distribution of the chemical elements present in the additive is inhomogeneous and has two fundamental differences in the oxygen (O) and carbon (C) content. ARMIDON additives contain more than 79% carbon (C) and ju...

Paper sheets were produced from bleached kraft pulp, and office and newsprint waste paper. Nanoparticles from black alder bark, grey alder bark and pine bark as well as birch sawdust were obtained for using them as reinforcing fillers in paper. Non-extracted bark and that extracted in biorefinery were used. For producing nanoparticles, the materials were destructed using the thermocatalytic destruction method and then dispersed in water medium in a ball mill. At a sufficient concentration, gel-like dispersions were obtained, which contained nanoparticles with the size ~300 nm. The dispersions were introduced in paper furnish in different amounts. It has been established that all the nanoparticle fillers increase the tensile index and burst index in dry and wet states. The nanoparticle fillers from extracted bark increase the mechanical indices to a higher extent. At 20% filler content, tensile index in a dry state increases in the case of non-extracted grey alder bark, black alder bark and pine bark by 28...

ECF technology has been established itself as the most preferred process worldwide. Peroxide addition minimizes the effluent color. The study deals with the bleaching of Bamboo and Jute Cady pulps with chlorine and peroxide treatment and identification of various chlorophenolics compounds. The results show that quantity of the total chlorophenolic compounds formed decreases up to 54% in total chlorophenolic compound in the CEH effluent and the COD and color values are reduced by 35% and 33% respectively as E stage is changed to Ep stage in Bamboo pulp. And there is a reduction of 52% in total chlorophenolic compound in the CEH effluent when E stage is changed to Ep. and the COD and color values are reduced by 30% and 33% respectively as E stage is changed to Ep stage in Jute Cady pulp

During recycling of waste paper from private households different fractions containing plastics and polluted paper fibers are received. Current research at the Institute of Polymer Materials and Plastics Engineering at Clausthal University of Technology showed that the use of waste paper as filler and reinforcement in polypropylene leads to nearly the same mechanical properties as natural fibers like flax, sisal and hemp. The present investigations focus on the chemical cleaning of the paper recyclate to treat the fiber surface and to solve foreign plastics like polystyrene. For this purpose Soxhlet extraction with different solvents is used. The received extracts are examined via infrared spectroscopy, as well as the treated and the untreated fibers. Afterwards, the cleaned paper is incorporated into polypropylene. The received composites are investigated regarding their mechanical properties by tensile testing and Charpy impact testing.During recycling of waste paper from private households different fractions containing plastics and polluted paper fibers are received. Current research at the Institute of Polymer Materials and Plastics Engineering at Clausthal University of Technology showed that the use of waste paper as filler and reinforcement in polypropylene leads to nearly the same mechanical properties as natural fibers like flax, sisal and hemp. The present investigations focus on the chemical cleaning of the paper recyclate to treat the fiber surface and to solve foreign plastics like polystyrene. For this purpose Soxhlet extraction with different solvents is used. The received extracts are examined via infrared spectroscopy, as well as the treated and the untreated fibers. Afterwards, the cleaned paper is incorporated into polypropylene. The received composites are investigated regarding their mechanical properties by tensile testing and Charpy impact testing.

This paper presents the laboratory result on compaction characteristic for soft soil subgrade which was stabilized by using waste paper sludge ash (WPSA). The soft soil sample was collected from Banting Selangor, Malaysia named as Banting soft soil and classified as slightly sandy Clay with intermediate plasticity. Additive of WPSA is a finely waste product produced from the incinerated waste paper. In ASTM C618, this WPSA samples are categorized as Type-C fly ash due to the high free lime (CaO) content (>20%) and possesses some cementitious and pozzolanic, resulting in the self-cementing characteristics. Therefore no entire activators such as lime are required. Objectives of this study are to determine the dry density and moisture content of Banting soft soil stabilized by WPSA through the different energy and method of compaction and to determine the Atterberg limit properties of Banting soft soil stabilized using WPSA. Several percentage of WPSA (4%, 8%, 12% and 16%) was used to stabilize the soft soil...

In this paper the utilization of hypo sludge in bricks and its characteristics have been tested. Hypo sludge is a byproduct obtained in huge quantity from paper industry. The reference bricks are manufactured with the ingredients of cement, fly ash, quarry dust and lime. Hypo sludge contains high value of CaO, so that the study on hypo sludge partially replaced on lime in reference to bricks. Hypo sludge is traditional material used on lime in various percentages of 10%, 15% and 20%. The preliminary test conducted was compression and water absorption and the experimental results indicate with sustainability on environmental and also prevent the wastages.

The present study was carried out to beneficiate coal tailings sample using froth flotation technique. The aim of the investigation was to remove the carbonaceous material present and to reduce the environmental pollution generated through large volume of tailings from a coal preparation plant. The characterization studies show that the sample contains D80 passing size as 276 µ and D50 as 182 µ. The proximate analysis indicated that the coal sample contains 45.3% ash and 34.5% fixed carbon. Froth flotation experiments were carried out at varying parameters of collector dosages (0.60, 0.67 & 0.71 kgpt), frother dosages (0.33, 0.44& 0.51 kgpt) and pulp density (8%, 10% & 12% w/w). The experimental results indicated that the optimum amount of clean coal may be recovered from tailings with an ash content of 18.46% in the clean coal with an appreciable yield of 64.13%. The optimum results were obtained at frother dosage of 0.44 kgpt and collector dosage of 0.60 kgpt with pulp density of 10% (w/w).

The use of magnetite nanoparticles to produce magnetic paper has a severe effect on the color of the paper, which is worth searching means to alleviate. Multicore-shell Fe3O4-SiO2 magnetic nanocomposites were synthesized. The nanocomposite powder was dispersed in cellulose pulp and paper was produced by dehydration on a Rapid Kothen machine. The nanocomposite retention efficiency was investigated in correlation with nanocomposite shell thickness, the resinous vs. deciduous fiber content of the cellulose pulp, the long and short fibers’ grinding degree, the cationic starch and polymeric retention agent content of the pulp. The whiteness and magnetization was measured for all paper samples. It was proved that the use of multi-core shell magnetic nanocomposites leads to weaker paper coloring. This effect is enhanced by increasing the polymeric retention agent content of the pulp, in spite of higher composite content.

Indonesia has large areas of cacao (Theobroma cacao L) plantation, which mostly plant by smallholders (94%), inconsequences it produces waste. Wastes are in the form of cacao pods and placenta or pulp, leaves, and twigs. One of the methods used to handle cacao waste is by composting. Research is done by adding activators to accelerate the composting. Activators used are Effective Microorganism 4 (EM4), Beyonic Startmix biological organic fertilizer and Suburnik liquid organic fertilizer. Cacao waste used is from smallholder cacao plantation located in Pangadegan village, Rancakalong Sub-district, Sumedang Regency of Indonesia. Composting is done in a composter made of vats with a capacity of 50 liters. Monitored parameters include composting temperature, ambient temperature. The testing of compost products includes chemical and physical quality testing. Chemical quality tests include pH value, moisture content, C-organic, total Nitrogen, C/N ratio, P2O5, K2O, ash content, CaO, MgO, S, Fe, Cu, B, Al. Physical quality tests include color and odor. The test results showed that the chemical and physical quality of the compost in the three activator materials used to produce compost that is not significantly different with the quality that meets the criteria of compost quality according to Indonesian National Standard number 19-7-30-2004. Beyonic Startmix activator is the best activator, followed by EM4 and Suburnik.

Food waste is one of the wastes that is being generated about every day. It would be a waste if the generated waste is ignored, neglected and just being disposed of without using the benefits that are in the food waste. The aim of this study is to find the best way for food waste recovery by using effective microbes (EM). There are three different parameters used in this study. The parameters are the method of drying the food wastes, the presence of Effective Microbes (EM) after the drying of food wastes and the addition of wheat pollard. An effective microbe is a combination of anaerobic microorganisms in a liquid. The effective microbe is activated by mixing the EM 1 with molasses and water with the ratio of 1:1:20 and is left for a week. Molasses is a thick liquid of sugar from the plant such as sugarcane. The food waste went through three processes for it to be recovered which are drip the food waste leaching water at the designated table, grind the food waste and lastly dry it. Before grinding, the coconut pulp was added to the food waste. The food waste is analysed based on four analyses. The four analyses are moisture content, protein analysis, E-coli analysis and Fourier-transform infrared spectroscopy analysis (FTIR). Moisture content was done to analyse the amount of water in the food waste by using the weight before and after the drying process. Two types of drying process were used in this study; drying by oven and conventional fan. Based on moisture content, the best drying method is by using the oven. The result shows that the moisture content is 28% when the sample dried using an oven compared to a conventional fan (51.4%). Protein analysis and E-Coli analysis are conducted to find an amount of protein and E-coli respectively in the sample. Fourier-transform infrared is an analyzing process to observe the absorption spectra of the food.

Acacia Mangium and Eucalyptus Pellita had been used as raw material of pulp in Indonesia. In this research 5-year old of the wood were pulped under different active alkali charge varied at 16, 17, 18, 19 and 20% and its effect on pulp yield, pulp viscosity and kappa number was investigated. The cooking was done in a rotating digester Haato 6 chambers and 300 gram of dry mass chips were used, with sulfidity 25%, H-factor 800, temperature 165˚C and ratio between chips and liquid was 1: 3,5. The pulp screened yield indicates that decreased from 53,7 to 52,25% for acacia mangium and 53,0 to 50,6% for eucalyptus pellita when active alkali charge increased. Kappa number decreased from 19,0 to 16,8 for acacia mangium and 16,69 to 13,4 for eucalyptus pellita when active alkali charge increased. The viscosity decreased from 818 to 378 ml/g for acacia mangium and 697 to 426,8 ml/g for eucalyptus pellita when active alkali charge increased.

Due to population rapid growth, fertilizer industries have to increase the production to ensure food security causing faster non-renewable resource depletion. However, organic wastewater (cow urine) commonly contains high amount in NH4+ and PO43- is still underutilized and causing eutrophication and unpleasant odour problem. Struvite precipitation, a common technique using for nitrogen and phosphorus recovery from wastewater,is proposed to recover the organic and renewable nutrients sources. Struvite precipitation process for nutrients recovery/removal from waste sources is beneficial not only providing slow-releasing and high-quality fertilizer but also reducing soil and water pollution from rich-nutrients wastewater. This research aimed to utilize the cow urine wastes as the raw material for the struvite precipitation, to determine the influence of the PO43-: Mg2+ concentration, and input flowrate on a continuous reactor to the struvite formation. Struvite was made using continuous method with variation of the PO43-: Mg2+ concentrations ratio of 1:1; 1:2 and 1:4 and the inlet flowrate of 8.2 mL/s and 15.8 mL/s. The results of this study show that the increase of MgCl2 addition and the higher flow rate could increase the P removal efficiency of struvite in reactors. The optimum phosphate removal efficiency at the flow rate of 8.2 mL/s is obtained at 80 mins with the percentage of 54%, while at the flow rate of 15.8 mL/s, 43% of P removal is obtained at 70 mins. The results from the kinetic study in the input flowrate was found that the higher the concentration ratio of PO43- and Mg2+, the greater the value of the reaction rate constant. However, for molar ratio 1:1 of PO43-: Mg2+, the greater the input flow rate, the smaller value of the reaction rate constant was obtained. From this study, it is revealed that the molar ratio of PO43-: Mg2+ and aeration rate affect significantly the struvite precipitation.

In this study, the sludge of three municipal sewage treatment plants in Foshan City, Guangdong Province, China, was dewatered and recycled. The experimental results shown that after deep dewatering with different chemical conditioning reagents, the moisture content of municipal sewage sludge was decreased greatly, from about 97% to about 55%. After dewatering, the organic matter content of sludge was maintained at a high level which is beneficial to the composting treatment of the sludge. The organic matter content of sludge in Foshan No. 1 Sewage Treatment Plant and No. 2 Sewage Treatment Plant was more than 30%, while it was between 15% and 20% in Foshan No. 3 Sewage Treatment Plant. Sludge from all three sewage treatment plants neeed to add a small amount of nutrients to compost. After 14 days of the aerobic composting, the moisture content of the sewage sludge could be reduced to less than 50%, and all the index met the requirements of the agricultural standard.

Seawater ice slurry can be produced with cooling process in evaporator by utilizing salt content in the seawater as freezing point depressing additive. Ice slurry technology can play an important role in the process of storing fish in the open sea because the quality of the fish that cooled with ice slurry is much better than ice cubes. Evaporator with polytetrafluoroethylene (PTFE) coating blade and a certain clearance distance, around five milimeters, can reduce electric power and time consumption in ice slurry generation. PTFE, more commonly known as Teflon, is suitable for a wide range of applications in industries as diverse as aerospace, the food and drink industry, pharmaceuticals and telecoms. The present study used variation of magnetic chemical pump RPM, scraper RPM, and salinity of seawater. The results show that the higher salinity results in the lower temperature of ice slurry generation and decreases ice slurry generation. The experimental condition with higher scraper RPM result in slower ice slurry generation. There is an optimum pump RPM to decreasing the temperature faster. Seawater with lower salinity was changed into ice slurry faster, increased the production of ice slurry, and consumed less electric power than that of higher salinity.

Microbiological Influenced Corrosion (MIC) is corrosion exacerbated by the activity of microorganisms. One environment that contains microorganisms is crude oil where there is anaerobic bacterium of Sulphate Reducing Bacteria (SRB) [1]. To study the effect of SRB on corrosion, a study was conducted on JIS G3101 low carbon steel with grade SS400 on crude oil under aerobic and anaerobic conditions. In a mixture of 50 mL crude oil and 10 mL SRB (one solution), and 30 mL of crude oil was added 30 mL SRB (other solution) was immersed specimen with the dimension of 20 x 20 x 4 mm. The bacterium used is SRB of Desulvofibrio desulfuricans genus with conditioning time for 60 days. In every 15 days periodically, there was done an observation of the corrosion phenomena occurring on the specimen, the test of corrosion product compounds on the metal surface layer, and the calculation of bacterial counts. The results of this research indicate that the activity of SRB metabolism in crude oil caused damage to the metal shown by the color change on the specimen surface with the occurrence of pitting corrosion. The more SRB is in crude oil, the more bacteria grow on the specimen surface so that the damage on the specimen surface is getting worse. It caused a more and deeper pitting corrosion. In addition, the anaerobic condition exacerbated the corrosion occurred.

Cellulose is one of the most abundantly available biopolymer in nature. This semi crystalline cellulose cannot be melted directly to form fiber, as it degrades before melting. Hence processing of cellulosic fiber requires dissolution process. There are many solvents available for direct dissolution of cellulose to form polymer, N-Methyl Morpholine Oxide (NMMO) is one of the solvents, which has commercial feasibility to dissolve the cellulose to form spinnable polymer matrix. The process of direct dissolution of cellulose using NMMO is conventionally termed as Lyocell process. It is a multiple step process that involves swelling and dissolution of cellulose in N-Methyl Morpholine Oxide (NMMO) solvent and spinning of solvated cellulose solution to produce fiber by dry jet wet spinning. The conventional process of lyocell manufacturing consists of single stage of slurry (cellulose suspension in NMMO) preparation in which solvent gets penetrated in cellulose fibers (Swelling). It is necessary at slurry stage to have optimum pulp swelling and higher NMMO to cellulose ratio to achieve better uniformity of slurry for fast dissolution and homogeneous solvated cellulose polymer formation. To achieve this, pulp sheets are shredded to an optimum size before addition to aqueous solution of NMMO. The shredding of pulp sheet requires intensive energy and raises safety concerns due to the static charge generation which can lead to dust explosion. This makes conventional processes of dissolved cellulose preparation commercially and operationally unviable. In the present work a new method is developed to overcome the safety concern. In this new method, slurry preparation is carried out in two stages. In first stage dilute solvent is used to prepare slurry with low (4-6%) solid, slurry is later pressed to upto 45-50% solid percentage, the pressed solvent removes metal ion impurities and short chain hemicellulose by 10-20% from pulp. The pressed cake of cellulose is again mixed with high concentration of NMMO to form the slurry mixture for further processing. The dissolution of cellulose starts when monohydrate state of NMMO is reached by removing excess water from cellulose NMMO slurry to get Lyocell dope at 90-100 °C. This polymer solution is then spun through spinnerets by jet-wet spinning to get the Lyocell fiber. This method of cellulose-NMMO slurry preparation for the manufacturing lyocell fiber has shown reduction in undissolved particles of cellulose and metal ions impurities in polymer matrix of cellulose with no change in the fiber properties compared to the conventional process. The advantage of this process over conventional process is that high impurity pulp can be easily blended with good quality pulp in first stage of slurry-making, while the excess impurity is removed before second stage to get better quality of solvated cellulosic polymer network.

Char resulted from the gasification of empty fruit bunch (EFB) is a potential source of some components that can be used as a material in the production of NPK fertilizer. Beside that char also has a porous surface which allows it to hold the nutrients in fertilizer so that the utilization of char can give the positive effects to the availability of nutrient for the plant growth. That characteristics support the utilization of char as a supporting component for fertilizer production. In making the NPK slow release fertilizer, some main components that used in order to fulfill the need of nitrogen (N), phosphor (P), and potassium (K), were urea, diammonium phosphate (DAP), and potassium chloride (KCL). Zeolite was also used as a matrix to increase the character of the fertilizer. In this research, the materials above were formulated to produce the NPK slow release fertilizer for rice plant application by adding char as a source of potassium. The materials were crushed into powder form and then mixed and granulated with molasses as a binder to improve the adhesive strength of the granule fertilizer. In order to study the effect on the utilization of EFB char on the properties of the fertilizer, the NPK non-char fertilizer was also synthesized and characterized. The fertilizer product was then characterized to study about the surface area and pore volume, morphology, and its composition.

The paper discusses the possibility of using the flax boons for thermal insulation materials. The solution for systematization of materials based on flax boon is suggested. It based on the principle of building materials production using the flax waste with different types of binders. The purpose of the research is to obtain heat-insulating materials with different structure based on agricultural production waste - flax boon, mineral and organic binders. The composition and properties of organic filler – flax boons – are defined using infrared spectroscopy and standard techniques. Using the method of multivariate analysis the optimal ratio of flax boons and binders in production of pressed, porous and granular materials are determined. The effect of particles size distribution of flax boons on the strength of samples with the different composition is studied. As a result, the optimized compositions of pressed, porous and granular materials based on flax boons are obtained. Data on the physical and mechani...

Simultaneous Saccharification Fermentation (SSF) of palm oil (Elaeis guineensis) empty fruit bunch (EFB) pulp were investigated as a part of ethanol production process. SSF was investigated by observing the effect of substrate loading variation in range 10-20%w, cellulase loading 5-30 FPU/gr substrate and yeast addition 1-2%v to the ethanol yield. Mathematical model for describing the effects of these three variables to the ethanol yield were developed using Response Surface Methodology-Cheminformatics (RSM-CI). The model gave acceptable accuracy in predicting ethanol yield for Simultaneous Saccharification and Fermentation (SSF) with coefficient of determination (R2) 0.8899. Model validation based on data from previous study gave (R2) 0.7942 which was acceptable for using this model for trend prediction analysis. Trend prediction analysis based on model prediction yield showed that SSF gave trend for higher yield when the process was operated in high enzyme concentration and low substrate concentration. On the other hand, even SHF model showed better yield will be obtained if operated in lower substrate concentration, it still possible to operate in higher substrate concentration with slightly lower yield. Opportunity provided by SHF to operate in high loading substrate make it preferable option for application in commercial scale.

Kraft pulping of sweet sorghum bagasse (SSB) has been used for effective delignification method for cellulose production. This study was conducted to evaluate the performance pulp kraft of SSB for reducing sugar production. The study intended to investigate the effect of active alkali and sulfidity loading variation of SSB pulp kraft on reducing sugar yield per biomass. The SSB pulp was prepared after pulping using three variations of active alkali (17, 19, and 22%) and sulfidity loading (20, 22, and 24%) at 170°C for 4 h with liquor to wood ratio of 10. A total of 9 pulps were obtained from these pretreatments. Delignification pretreatment has been succesfully removed lignin and hemicellulose more than 90% and 50%, respectively. Increasing active alkali and sulfidity loading has significantly increased lignin removal caused by disruption of the cell wall structure for releasing lignin into black liquor in the cellulose extraction. The enzymatic hydrolysis of pulp was carried out with cellulase loading of 40 FPU per g substrate in the shaking incubator at 50°C and 150 rpm for 78 h. For each 24 h, the reducing sugar yield (DNS assay) has been observed. Even though the lignin and hemicellulose loss occurred along with higher active alkali loading, this condition tends to decrease its yield. The reducing sugar concentration varied between 7-8 g/L. Increasing active alkali and sulfidity was significantly decreased the reducing sugar per biomass. Pulp delignified by 17% active alkali and 20% sulfidity has demonstrated the maximum reducing sugar yield per biomass of 45.57% resulted after 72 h enzymatic hydrolysis. These results indicated that kraft pulping was success to degrade more lignin and hemicellulose content to facilitate the enzyme for breaking down the cellulose into its sugar monomer. A high loss of lignin and hemicellulose are not single factor to improve digestibility of SSB. This sugar has potential for yeast fermented into bioethanol.

The decomposition of green waste and brown waste in relative proportions of 1:1, 2:1 and 3:1 was studied in three successive experiments conducted at Desasiswa Bakti Permai, Universiti Sains Malaysia, Penang. The research involved the determination of the quality of compost produced from the different mixture ratio of green waste and brown waste. Three different 200L capacity reactor that made of 4mm thick poly vinyl chloride (PVC) was used as a Semi Passive Aerated Reactor. Temperature and pH were controlled over 89 days (three months) of composting process. Moisture Content, Calorific Value, C:N ratio and Germination Index of the compost product were analyzed. The final moisture content were 23%, 32% and 54% while the final C:N ratio were 23,21 and 14 respectively. The recommended mixture ratio for composting are in relative proportions 3:1 with final C/N ratio of 14 with Moisture content of 52% and 75% germinated seeds.

Liquid wastes produced by the textile industry in the immersing and dyeing process are confirmed to contain chemicals and heavy metals which have toxic and hazardous properties. If the wastewater is used continuously, it will have a great deal heavy metal pollution on the rice field. Pollution of heavy metals such as Cr in paddy field areas has implications on the absorption of Cr in plant tissue therefore if it is consumed every day, it will have bad impacts to human being. Bioremediation is an alternative to treating toxicity of heavy metals to plants on the contaminated soils. The purpose of this study was to determine the effect of bioremediation on the use of chelator agent and its combination of Cr concentration in soil and rice plant. This research was conducted in Kaling, Tasikmadu, Karanganyar. This research used field experiment with factorial design and Complete Randomized Block Design (CRBD). The treatments in this research are: (1) Giving basic fertilizer N, P, K; (2) Giving isolates agrobacterium sp. I37 or compost fertilizer. The data then were analyzed statistically using ANOVA F (Fisher Test) test of 5% level and LSD (Least Significant Differences). The results of this research showed that the use of Agrobacterium sp. I37 as a chelator agent is able to decrease Cr in soil at a higher level than other treatment by 56,52% from 2,3 mg.kg−1 to 1 mg.kg−1. The use of Agrobacterium sp. I37 as a chelator agent is able to decrease Cr in rice grains by 88.87% from 6.65 mg.kg−1 to 0.74 mg.kg−1. By the treatment code P0B1 and P0B2, It can be concluded that it can be as a suggestion to decrease levels of Cr on the grain of the rice.Liquid wastes produced by the textile industry in the immersing and dyeing process are confirmed to contain chemicals and heavy metals which have toxic and hazardous properties. If the wastewater is used continuously, it will have a great deal heavy metal pollution on the rice field. Pollution of heavy metals such as Cr in paddy field areas has implications on the absorption of Cr in plant tissue therefore if it is consumed every day, it will have bad impacts to human being. Bioremediation is an alternative to treating toxicity of heavy metals to plants on the contaminated soils. The purpose of this study was to determine the effect of bioremediation on the use of chelator agent and its combination of Cr concentration in soil and rice plant. This research was conducted in Kaling, Tasikmadu, Karanganyar. This research used field experiment with factorial design and Complete Randomized Block Design (CRBD). The treatments in this research are: (1) Giving basic fertilizer N, P, K; (2) Giving isolates agrobact...

Preliminary survey showed that organic waste from the market is about 18.77%, or second largest in the total waste generation. Its management becomes a challenge, because it is not comprised only of organics but also mixed with small amount of plastics; therefore, conventional biological process will not achieve their maximum efficiency. Wet torrefaction is a thermal process in hot water medium, which will dissolve organic materials into water, effectively converting most solids into liquid product. Banana fruit stem and cabbage were chosen as the mixed organic waste representative, and treated in a 2.5 L reactor using saturated steam in the temperature range of 175 to 225 °C before being analyzed for their heating value in solid products as fuel precursors, and their nitrogen, phosphorus and potassium (NPK) contents in liquid products as liquid fertilizer precursors. It was found that for cabbage, the wet torrefaction process at 200 °C and 90 min resulted in 15.59 MJ/kg product heating value with NPK content of 3.43%. For banana fruit bunch stem, the wet torrefaction process at 225 °C and 30 min resulted in 17.64 MJ/kg product heating value with NPK content of 5.13%. It can be concluded that wet torrefaction process can simultaneously produce solid and liquid product as solid fuel and liquid fertilizer, respectively.

Grapefruit (Citrus paradisi) seed extract is generally used as naturopathic medications, supplements, antiseptic and disinfecting agents and also as preservatives in food and cosmetics products. In vitro studies have demonstrated that grapefruit seed extract has anti bacterial properties against a range of gram-positive and gram-negative organisms. Indonesian grapefruit, known as pomelo (C. maxima), has similar characteristics, contents and is under the same genus (Citrus) as grapefruit; however it has not been completely utilized as a preservative. In this work we analyze the antimicrobial activities of ethanolic extract of Indonesian pomelo (C. maxima) seeds and pulp compared to the grapefruit (C. paradisi) seeds and pulp ethanolic extract. Ethanolic extracts of pomelo and grapefruit seeds and pulp are investigated for activities against Bacillus subtilis, Staphylococcus aureus, Escherichia coli and Candida albicans. The level of antimicrobial effects is established using agar diffusion method. Both of the ethanolic do not show any antimicrobial activities against C. albicans. The ethanolic extract of pomelo seeds and pulp used in this research give positive results with growth inhibition effect on B. subtilis, S. aureus and E. coli. The zones of inhibition ranges from 22 – 30 mm in diameter, which is higher to grapefruit seeds and pulp ethanolic extract (17 – 25 mm). Ethanolic extract of pomelo seeds and pulp has an antimicrobial effect, which makes it a natural preparation for use as an alternative preservative for food and cosmetic.

Food wastes disposed at landfills can be recovered and transformed into value-added product, which helps to solve the environmental issues of solid waste. In this study, a composting method whereby food wastes are converted into compost through decomposition by inoculants. The decomposition rate of the food wastes and dried leaves was enhanced by the compost functions as fertilisers for soil and plants. The proposed modified compost bin is an effective solution to decompose the food wastes which are placed evenly alternating between the dead leaves. The inoculant was poured onto the food waste and then layered by the dead leaves. The ratio of food wastes to dead leaves is 2:1. The inoculants used were Effective Microorganisms (EM), vermitea (VCT), obsolete pasteurised milk (OPM) and the control bin without any inoculant, respectively. The temperature and pH of each compost were monitored every three to four days for 10 weeks. It was found that the EM assisted compost stabilised faster compared to the other three of the VCT, OPM and control composts. By week 7, the EM compost has achieved all the criterion to be considered as stable and matured compost whereas the VCT compost achieved all the criterion only by week 9 but the OPM assisted compost did not meet all the criterion even by week 10. In week 7, the EM assisted compost showed the temperature of 22.4±0.55°C with pH 7.7±0.01. The moisture content, in the beginning, was 56% and at the end was 32% with a decreased of 24%. The C/N ratio is 12.48 and the germination test using mung beans showed that the compost has achieved 75% and is suitable to be used as fertilizer.

Bioethanol G2 production using oil palm empty fruit bunch as raw material consists of four steps, namely pretreatment, hydrolysis, fermentation, and purification process. Pretreatment process generates black liquor that causes serious environmental pollution if it is released to the environment. The objective of this research is studying the ability of iron oxide coating sands to adsorb the color of black liquor. The iron oxide coating sands were synthesized from FeCl3.6H2O with quartz sands as support material. This research was conducted on batch mode using black liquor in various pH values. Result obtained that kind of iron oxide on quartz sands’s surface was goethite. The result also indicated decreasing of color intensity of black liquor after adsorption process. This research supports local material utilization in environmental technology development to solve some environmental problems.

The extraction of recycled newspapers (RNP) cellulose pulp began by a series of chemical alkali extraction, 5 wt% NaOH at 125°C for 2 h. Subsequently, the bleaching of alkalized pulp was carried out by using 2 wt% NaClO2 solutions in the presence of 60 wt% of nitric acid, for 4 h at 100°C. The graft copolymerization of acrylonitrile onto the bleached cellulose pulp was initiated by using ceric ammonium nitrate. The grafting conditions were optimized by varying the ceric ammonium nitrate (CAN) initiator concentration, acrylonitrile (ACN) concentration and reaction time. The successfully of the grafting process were determined by calculating the grafting yield (%GY) and grafting efficiency (%GE). The morphological and chemical structure of resulting grafted and ungrafted recycled newspaper cellulose pulp were characterized by using scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) spectroscopy.The extraction of recycled newspapers (RNP) cellulose pulp began by a series of chemical alkali extraction, 5 wt% NaOH at 125°C for 2 h. Subsequently, the bleaching of alkalized pulp was carried out by using 2 wt% NaClO2 solutions in the presence of 60 wt% of nitric acid, for 4 h at 100°C. The graft copolymerization of acrylonitrile onto the bleached cellulose pulp was initiated by using ceric ammonium nitrate. The grafting conditions were optimized by varying the ceric ammonium nitrate (CAN) initiator concentration, acrylonitrile (ACN) concentration and reaction time. The successfully of the grafting process were determined by calculating the grafting yield (%GY) and grafting efficiency (%GE). The morphological and chemical structure of resulting grafted and ungrafted recycled newspaper cellulose pulp were characterized by using scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) spectroscopy.

This study focus on Fourier Transform Infrared Spectroscopy (FTIR) analysis of paddy straw pulp treated using deep eutectic solvent (DES). DES was synthesized using potassium carbonate and glycerol at different molar ratio under normal atmospheric pressure. Pretreatment of lignocellulosic biomass was carried out at temperature of 120°C for 60 minutes under mass ratio of paddy straw to DES 1:9. The chemical structures of the untreated paddy straw and paddy straw pulp treated with different molar ratio of DES were analyzed using FTIR. The characterization result from FT-IR spectra indicated that the potassium carbonate-glycerol DES deconstructed the structures of paddy straw by removing lignin and hemicellulose during the pulping process. The peak intensity that occurs at region between 900 cm−1 and 1500 cm−1 shows that the presence of elevated level of cellulose after lignocellulosic pulping. From FT-IR analysis, DES could not remove the functional group of lignin and hemicellulose completely but yet expos...

Providing affordable housing is the most critical problem in many of the developing countries. Using earth materials in building construction is one of the feasible methods to address this issue and it can be a way towards sustainable construction as well. However, the published information on the stabilized soil blocks is limited. Therefore, the present study is conducted to examine the characterization of the soils and engineering properties of the stabilized soil blocks. Four types of stabilizer were used in the study, namely; cement, slaked lime, bitumen emulsion and calcium silicate. Cement and slaked lime were added at different percentages in the range of 5% to 15%, with interval of 2.5%. The percentage was determined based on weight of soil. Meanwhile, bitumen emulsion and calcium silicate were incorporated at various percentages together with 10% of cement. Dosage of bitumen emulsion is in the range of 2% to 10% at interval of 2% while calcium silicate was incorporated at 0.50%, 0.75%, 1.00%, 1.2...

The utilization of thermophilic microbe has attracted many parties, particularly in producing an alternative fuel like ethanol. Bioethanol is one of the alternative energy sources substituting for earth oil in the future. The advantage of using bioethanol is that it can reduce pollution levels and global warming because the result of bioethanol burning doesn’t bring in a net addition of CO2 into environment. Moreover, decrease in the reserves of earth oil globally has also contributed to the notion on searching renewable energy resources such as bioethanol. Indonesia has a high biomass potential and can be used as raw material for bioethanol. The utilization of these raw materials will reduce fears of competition foodstuffs for energy production. The enzymes that play a role in degrading lignocelluloses are cellulolytic, hemicellulolytic, and lignolytic in nature. The main enzyme with an important role in bioethanol production is a complex enzyme capable of degrading lignocelluloses. The enzyme can be pro...

Gold amalgamation process was widely used to treat gold ore. This process produces the tailing or amalgamation solid waste, which still contains gold at 8-9 ppm. Froth flotation is one of the promising methods to beneficiate gold from this tailing. However, this process requires optimal conditions which depends on the type of raw material. In this study, Taguchi method was used to optimize the optimum conditions of the froth flotation process. The Taguchi optimization shows that the gold recovery was strongly influenced by the particle size which is the best particle size at 150 mesh followed by the Potassium amyl xanthate concentration, pH and pine oil concentration at 1133.98, 4535.92 and 68.04 gr/ton amalgamation tailing, respectively.Gold amalgamation process was widely used to treat gold ore. This process produces the tailing or amalgamation solid waste, which still contains gold at 8-9 ppm. Froth flotation is one of the promising methods to beneficiate gold from this tailing. However, this process requires optimal conditions which depends on the type of raw material. In this study, Taguchi method was used to optimize the optimum conditions of the froth flotation process. The Taguchi optimization shows that the gold recovery was strongly influenced by the particle size which is the best particle size at 150 mesh followed by the Potassium amyl xanthate concentration, pH and pine oil concentration at 1133.98, 4535.92 and 68.04 gr/ton amalgamation tailing, respectively.

Pilot scale experiments were conducted to prepare magnesium hydroxide by magnesia hydration under gas-liquid-solid (three-phase) reaction system. The effect of reaction pressure, reactivity and particle size of magnesia and the concentration of the pulp on the degree of hydration was investigated. The results indicated that the hydration reaction occurred at the first 30min mainly. During the set reaction condition, degree of hydration of 68% could be obtained at the reaction pressure of 0.2MPa, concentration of pulp of 5%w/w with high reactivity and fine powder. The promotion effect on the degree of hydration caused by the three-phase reaction system was mostly attributed to the exfoliation of steam.

Coffee is an excellent commodity in Indonesia that has big problem in utilizing its wastes. As the solution, the abundant coffee pulp waste from processing of coffee bean industry has been used as a substrate of biogas production. Coffee pulp waste (CPW) was approximately 48% of total weight, consisting 42% of the coffee pulp and 6% of the seed coat. CPW holds good composition as biogas substrate that is consist of cellulose (63%), hemicellulose (2.3%) and protein (11.5%). Methane production from coffee pulp waste still has much problems because of toxic chemicals content such as caffeine, tannin, and total phenol which can inhibit the biogas production. In this case, CPW was pretreated by ethanol/water (50/50, v/v) at room temperature to remove those inhibitors. This study was to compare the methane production by microbial consortium of cow dung and rumen fluid mixture coffee pulp waste as a substrate with and without pretreatment. The pretreated CPW was fermented with mixture of Cow Dung (CD) and Rumen Fluid (RF) in anaerobic co-digestion for 30 days at mesophilic temperature (30-40°C) and the pH was maintained from 6.8 to 7.2 on a reactor with working volume of 3.6 liters. There were two reactors with each containing the mixture of CPW without pretreatment, cow dung and rumen fluid (CD+RF+CPW) and then compared with the CPW with pretreatment (CD+RF+PCPW) reactor. The measured parameters included the decreasing of inhibitor compound concentration, Volatile Fatty Acids (VFAs), Chemical Oxygen Demand (COD), Total Solid (TS), Volatile Solid (VS), Methane and the Calorific value of gas (heating value) were studied as well. The result showed a decrease in inhibitor component concentration due to methanol pretreatment was 90% of caffeine; 78% of polyphenols (total phenol) and 66% of tannins. The highest methane content in biogas was produced in CD+RF+PCPW digester with concentration amounted of 44.56% with heating value of 27,770 BTU/gal.

The morphology and structural characteristics of celluloses obtained by different methods were studied. The objects of the investigation are cellulose from pulp source, commercial celluloses produced by sodium and acid hydrolysis, laboratory produced cellulose from bleached birch kraft pulp, and cellulose obtained by thermooxidative catalytic treatment of maple leaves by peroxide. According to a complex analysis of cellulose characteristics, several types of celluloses were offered as modifying additives for polymers.

The development of technology causes most of textile industries in Indonesia prefer to use synthetic dyes in the fabric dyeing process. In fact, synthetic dyes is able to have negative effect since it is is toxic to the health of workers and environment. To resolve this issues, one way to do is to use natural dyes. One of untapped potential in Indonesia is wood waste of jackfruit from furniture industry. Jackfruit wood itself containing dyestuffs which gives yellow color pigment so that it can be used as an alternative source of natural dyes. The purpose of this research is to study the effect of extraction time, mass to solvent volume ratio, and microwave power to yield of dyes. The extract of dye analyzed by UV-Visible Spectrophotometer and GC-MS, along the coloring and endurance tests of natural dyes on fabric and compare it with synthetic dyes. In this research, material is going to be extracted is the wood of jackfruit (Artocarpus heterophyllus lamk) with material size between 35 mesh - 60 mesh. The ...

Aquaculture activity on coastal area produces organic and inorganic waste that cause a high concentration of dissolved nutrient in waters. Therefore, the organic and inorganic waste should be reduced to prevent a negative impact to coastal water. One way to reduce the aquaculture waste loading to coastal water is to use it as a fertilizer on microalgae cultivation. The objective of this study was to investigate the change of dissolved nitrogen concentration in aquaculture waste during 14 days treatment in aerated and unaerated conditions. Two liters of wastewater was collected every 2 days from the reactor for culture media of microalgae Nannochloropsis oculata in 2 liters Erlenmeyer flask. The concentration of ammonia, nitrite, nitrate and phosphate were determined spectrophotometrically as well as chlorophyll-a content when waste were treated in aerated and unaerated reactor. Water temperature, dissolved oxygen, hydrogen ion and salinity were monitored throughout the treatment. Concentration of ammonia, nitrate and nitrite in aeration treatment were changed faster in aerated condition compared to unaerated condition. The phosphate concentration in both aerated and unaerated had a same pattern and these could reach the highest concentration to 0,9 mg L−1. Six days cultivation of N. oculata showed that N. oculata was able to assimilate nutrient from wastewater to construct its cell structure with the highest density of 19,75 × 106 cell mL−1 and its process caused extremely low nutrient concentration. This result showed that nutrient from aquaculture waste can be almost totally assimilated by N. oculata and create an extremely low concentration of nutrient from wastewater.

Cellulose was extracted from kenaf core pulp by a series of bleaching processes and subsequently dissolved using an alkaline NaOH/urea solvent at low temperature. The produced cellulose solution was coagulated with H2SO4 at concentration from 5 to 12 wt% to produce a series of regenerated cellulose (RC) membranes. The surface morphology, structure and physical properties of the membranes were measured with variable pressure scanning electron microscope (VPSEM), X-ray diffraction (XRD), UV-vis spectrophotometer and tensile testing. The results from VPSEM revealed that the pore size of the membranes changed as a function of the concentration of H2SO4 coagulant. RC membranes coagulated with relatively dilute H2SO4 solution exhibited better mechanical properties. Thus, this work provided a promising way to prepare cellulose membranes with different pore sizes and good physical properties.

A conventional composting process required long duration of 2-3 months to degrade organic waste. Composting duration reduction could be done using earthworms as decomposers. This study was to determine the compost production of garden waste using vermicomposting process and to determine the influence of earthworm number and the composition of organic waste in vermicomposting process. Sixteen rectangular reactors were used with a volume of 8 L using Eisenia fetida earthworm. The reactors used in duplicate reactors and operated in 60 days. Twelve reactors were set up in which six reactors used only garden waste and the other six reactors used garden waste mixed with cow manure by a composition ratio of 2:1, whereas, four reactors acted as controls without earthworm. Earthworm to organic waste ratio was varied in 15, 35 and 60 g/kg based on dried mass. Several parameters were analyzed i.e. ammonia nitrogen (NH3-N), nitrate nitrogen (NO3-N), Total Kjeldahl Nitrogen (TKN), C/N, pH and moisture. The results sho...

The fabrication and characterization on reduced graphene oxide field effect transistor (RGO-FET) were demonstrated using a spray deposition method for biological sensing device purpose. A spray method is a fast, low-cost and simple technique to deposit graphene and the most promising technology due to ideal coating on variety of substrates and high production speed. The fabrication method was demonstrated for developing a label free aptamer reduced graphene oxide field effect transistor biosensor. Reduced graphene oxide (RGO) was obtained by heating on hot plate fixed at various temperatures of 100, 200 and 300°C, respectively. The surface morphology of RGO were examined via atomic force microscopy to observed the temperature effect of produced RGO. The electrical measurement verify the performance of electrical conducting RGO-FET at temperature 300°C is better as compared to other temperature due to the removal of oxygen groups in GO. Thus, reduced graphene oxide was a promising material for biosensor application.

CPO prices are unstable, therefore affecting the supply of feedstock to produce biodiesel [2]. To overcome the shortage of feedstock, it is necessary to use multiple feedstock, in this case is CPO and Jatropha [1]. This objective of this work to optimizate biodiesel production using multifeedstock (CPO and Jatropha) with assistance of ultrasound. The optimization was to find the highest yield and the least production time. Experiments was carried out using an ultrasonic bath at a frequency of 40 kHz. The ratio of CPO and Jatropha was 1: 1, 3: 1, 4: 1 while the ratio of methanol and oil was 5: 1, 6: 1, 7: 1 and the reaction time was 50, 60, and 70 minutes. KOH was used as a catalyst. The experiment data was optimized using a Response Surface Methodology [3,4]. The optimum point was at a frequency of 40 kHz obtained at a 2.8: 1 mixture of CPO - Jatropha, 6.4: 1 molar ratio of methanol-oil and 61.5 minutes of reaction time. The results of quality testing shows that the biodiesel produced meets the ASTM stand...

A single crystal CVD diamond detector with graphitic wire electrodes running beneath the diamond surface has been fabricated. This detector design is novel in that there is no surface metallisation present within the active region, and so the detector is a uniquely transmissive X-ray beam diagnostic instrument. This detector is designed to simultaneously measure the position, profile, and flux of an incident beam. It has applications in beam position and profile monitoring, and active beam feedback and stabilisation. To achieve this, a short-pulse laser, focused to micron-sizes using adaptive optics, can be used to graphitise arbitrary wire paths within bulk diamond. Presented in this paper is a transmissive X-ray pixel detector design with a 50-micrometre pixel pitch created using this technique. This pixel detector is produced by fabricating two separate arrays of parallel wires running under the surface of a diamond plate. The two arrays run perpendicular to each other, and parallel to the diamond surface. They are separated within the material by a depth of 100 microns. The parallel wires within each array are separated by 50-microns, and this is what determines the pixel pitch. Each of the crossing points between two wires from each array acts as a pixel. The signal from each pixel may be read out by measuring the signal current from each wire in one array whilst applying a bias voltage alternately to each wire in the other, perpendicular array. Alternatively, it is proposed to modulate the bias applied to each wire at a different frequency, from which the 2-dimensional beam profile may also be measured using a lock-in technique. This paper will provide an overview of the fabrication techniques for this first prototype detector, and provide a discussion of signal readout methods that will be used. An outline of the planned experimental tests is given.A single crystal CVD diamond detector with graphitic wire electrodes running beneath the diamond surface has been fabricated. This detector design is novel in that there is no surface metallisation present within the active region, and so the detector is a uniquely transmissive X-ray beam diagnostic instrument. This detector is designed to simultaneously measure the position, profile, and flux of an incident beam. It has applications in beam position and profile monitoring, and active beam feedback and stabilisation. To achieve this, a short-pulse laser, focused to micron-sizes using adaptive optics, can be used to graphitise arbitrary wire paths within bulk diamond. Presented in this paper is a transmissive X-ray pixel detector design with a 50-micrometre pixel pitch created using this technique. This pixel detector is produced by fabricating two separate arrays of parallel wires running under the surface of a diamond plate. The two arrays run perpendicular to each other, and parallel to the diamond surf...

Red Mud is a dust-like and high alkalinity waste material produced during the production of alumina from Bauxite ore by Bayer Process. Nearly 1 – 2.5 tons of Red mud, which consists of various oxides are produced per ton of alumina. The current practice is the disposal into long-term-storage sites, which is a major environmental problem throughout the world. Now the question comes: why to throw this valuable material as industrial waste and create environmental pollution instead of reusing it. This paper examines various possibilities of exploitation and utilization of Red Mud.Red Mud is a dust-like and high alkalinity waste material produced during the production of alumina from Bauxite ore by Bayer Process. Nearly 1 – 2.5 tons of Red mud, which consists of various oxides are produced per ton of alumina. The current practice is the disposal into long-term-storage sites, which is a major environmental problem throughout the world. Now the question comes: why to throw this valuable material as industrial waste and create environmental pollution instead of reusing it. This paper examines various possibilities of exploitation and utilization of Red Mud.

This paper presents developments contributing to the improvement of thermo-reactive deposition (TRD) process in producing hard carbide layers, on automotive components application. The problem in using FeV powder as a coating material that has been applied in the industries is it is high cost. In this study, FeCr powder coating material was mixed into FeV powder with a ratio of 35:65 weight percent. The SUJ2 steel pins components are processed at 980° C, with varying TRD time was 4,6,8 and 10 hours. Scanning Electron microscope (SEM), Electron Probe Micro Analyzer (EPMA) and X-ray diffraction (XRD) were applied to analyze the coating layers. The thickness of the carbide layer formed will increase with the longer processing time, which thickness at 4-10 hours is increase from 22.7 to 29.7 micron. The gained thickness tends to be homogeneous. Increasing the TRD process holding time results in a higher hardness of the carbide layerwith hardness at 4, 6, 8 and 10 hours is 2049, 2184, 2175 and 2343 HV. The wear rate at TRD holding time of 4-10 hours with the Ogoshi method was reduced from 5.1 × 10-4 mm3/m to 2.5 × 10-4 mm3/m. Optical microscope observations shows that substrate phases consisting of pearlite and cementite and grains that tend to enlarge with the addition of time. Carbide compounds that are formed are vanadium carbide (V8C7, V6C5, V2C) and chromium carbide (Cr3C2, Cr23C7, Cr3C7). While EDS-Linescan results show complex phase (Fe, V, Cr) xC formed. The research shows that addition of FeCr into FeV powder in TRD process in 980°C with optimum time of 10 hours processing meet the mechanical properties requirement of automotive components.This paper presents developments contributing to the improvement of thermo-reactive deposition (TRD) process in producing hard carbide layers, on automotive components application. The problem in using FeV powder as a coating material that has been applied in the industries is it is high cost. In this study, FeCr powder coating material was mixed into FeV powder with a ratio of 35:65 weight percent. The SUJ2 steel pins components are processed at 980° C, with varying TRD time was 4,6,8 and 10 hours. Scanning Electron microscope (SEM), Electron Probe Micro Analyzer (EPMA) and X-ray diffraction (XRD) were applied to analyze the coating layers. The thickness of the carbide layer formed will increase with the longer processing time, which thickness at 4-10 hours is increase from 22.7 to 29.7 micron. The gained thickness tends to be homogeneous. Increasing the TRD process holding time results in a higher hardness of the carbide layerwith hardness at 4, 6, 8 and 10 hours is 2049, 2184, 2175 and 2343 HV. The wea...

Now a days red emitting Mn4+ activated dialkali fluorosilicate phosphors have found applications in solid state lighting and displays. In this paper we describe development of K2SiF6 phosphor doped with Mn synthesized by simple method using Si metal powder with addition of oxidizing agent KMnO4. The photoluminescence spectra of K2SiF6:Mn show that emission is in the red region. In addition to this we studied LED spectra by coating the LED with phosphor mixed in different proportions with epoxy.Now a days red emitting Mn4+ activated dialkali fluorosilicate phosphors have found applications in solid state lighting and displays. In this paper we describe development of K2SiF6 phosphor doped with Mn synthesized by simple method using Si metal powder with addition of oxidizing agent KMnO4. The photoluminescence spectra of K2SiF6:Mn show that emission is in the red region. In addition to this we studied LED spectra by coating the LED with phosphor mixed in different proportions with epoxy.

A method of thermal reduction of graphene oxide has been developed. Samples of paper-like graphene oxide film produced by the standard Hummers method were experienced by thermal processing at various temperatures which resulted in a partial reduction of graphene oxide which accompanied with an enhancement of the conductivity of this material. The most pronounced jump in the conductivity occurs at the annealing temperature of about 170°C, when the conductivity of the samples increased by 5 orders of magnitude comparing to the initial samples. The samples of partially reduced graphene oxide obtained were used for reinforcement of a steel surface. The reinforcement procedure was described in detail in the preceding work [1], where fullerene C60 and nanocarbon soot formed as a result of electrical arc sputtering followed by the extraction of fullerenes were used as a reinforcing coating. A film of partially reduced graphene oxide is applied on a steel surface after which the surface is experienced by laser. The dependences of the reinforcement degree on the degree of the graphene oxide reduction and the laser intensity are measured. The results of measurements indicate a notable (up to 400 %) enhancement of the microhardness of the surface processed so that the depth of the reinforcement layer accounts tens micrometers.A method of thermal reduction of graphene oxide has been developed. Samples of paper-like graphene oxide film produced by the standard Hummers method were experienced by thermal processing at various temperatures which resulted in a partial reduction of graphene oxide which accompanied with an enhancement of the conductivity of this material. The most pronounced jump in the conductivity occurs at the annealing temperature of about 170°C, when the conductivity of the samples increased by 5 orders of magnitude comparing to the initial samples. The samples of partially reduced graphene oxide obtained were used for reinforcement of a steel surface. The reinforcement procedure was described in detail in the preceding work [1], where fullerene C60 and nanocarbon soot formed as a result of electrical arc sputtering followed by the extraction of fullerenes were used as a reinforcing coating. A film of partially reduced graphene oxide is applied on a steel surface after which the surface is experienced by laser. T...

Erosion-corrosion is common engineering problem causes a deterioration failure in many industries including oil and gas production, drilling, process and transportation of minerals including oil sands. This paper highlights fine particles erosion studies on two materials of High-Density Polyethylene (HDPE) and carbon steel under wet sand impact conditions frequently encountered on pipeline surfaces of hydrocarbon production industry. In this study, we perform an experiment to study the influence of fine particle on erosion characteristics of High-Density Polyethylene (HDPE) and carbon steel. In the experimental setup, a closed loop wet erosion technique was adopted, in which the flow speed of a carrier medium was set to be 0.09 m/s and the configuration of the rectangular plate were specified for three impact angles of 30°, 90° and -30° with fine particle sizes of 60 µm. Scanning Electron Microscopic (SEM), hardness test and roughness test of the eroded specimens were conducted to understand characterization of the target surface. SEM and hardness analysis revealed that for carbon steel, the surface of sample angled at 90° encountered significant erosions under impact conditions. It was noticed that hardness of HDPE was not affected at 90° and it encountered less surface roughness loss compared to carbon steel.Erosion-corrosion is common engineering problem causes a deterioration failure in many industries including oil and gas production, drilling, process and transportation of minerals including oil sands. This paper highlights fine particles erosion studies on two materials of High-Density Polyethylene (HDPE) and carbon steel under wet sand impact conditions frequently encountered on pipeline surfaces of hydrocarbon production industry. In this study, we perform an experiment to study the influence of fine particle on erosion characteristics of High-Density Polyethylene (HDPE) and carbon steel. In the experimental setup, a closed loop wet erosion technique was adopted, in which the flow speed of a carrier medium was set to be 0.09 m/s and the configuration of the rectangular plate were specified for three impact angles of 30°, 90° and -30° with fine particle sizes of 60 µm. Scanning Electron Microscopic (SEM), hardness test and roughness test of the eroded specimens were conducted to understand characterizat...

This paper describes the results of an experimental investigation aimed to st udy the machinability of AA7075 T6 (160 HV) for aerospace industry at high cutting speeds. The paper investigates the effects of different lubri-cooling strategies (cryogenic, M QL and dry) during high speed turning process on cutting forces, tool wear, chip morphology and cutting temperatures. The cutting speeds selected were 1000m/min, 1250m/min and 1500 m/min, while the feed rate values used were 0.1mm/rev and 0.3 mm/rev. The results of cryogenic and M QL application is compared with dry application. It was found that the cryogenic and M QL lubri-cooling techniques could represent a functional alternative to the common dry cutting application in order to implement a more effect ive high speed turning process. Higher cuttingparameters would be able to increase the productivity and reduce the production costs. The effects of the cutting parameters and on the variables object of study were investigated and the role of the different lubri-cooling conditions was assessed.

Chemical stabilization by cement or lime is a proven technique for improving the engineering properties of soil particularly the compressive strength. However, this cemented soil usually shows the brittle behavior or sudden failure with little or no plastic deformation. Fiber, either synthetic or natural can be added to solve this problem. This area of research is particularly important for deep soil mixing as retaining structure or foundations on stabilized soil. Early research on fiber reinforced cemented soils focuses more on the comprehensive behaviour and only little attention has been paid on the tensile behaviour. This paper aims to appraise the current development on the study of the tensile behavior of the fiber reinforced cemented soil and points out the gap of research in the conclusion.Chemical stabilization by cement or lime is a proven technique for improving the engineering properties of soil particularly the compressive strength. However, this cemented soil usually shows the brittle behavior or sudden failure with little or no plastic deformation. Fiber, either synthetic or natural can be added to solve this problem. This area of research is particularly important for deep soil mixing as retaining structure or foundations on stabilized soil. Early research on fiber reinforced cemented soils focuses more on the comprehensive behaviour and only little attention has been paid on the tensile behaviour. This paper aims to appraise the current development on the study of the tensile behavior of the fiber reinforced cemented soil and points out the gap of research in the conclusion.

Recently, some cheap materials are available and adaptable to climate seem to meet current requirements. This paper investigates the thermal and mechanical properties of cement stabilized earth bricks(CSEB) reinforced with date palm fibers (DPF). The main goal is to develop and expand the field of use of these materials in the construction sector, and investigate the possibility of new bio composite as renewable, insulating building material with low cost, made of earth and reinforced with palm wood waste. In this study, a particular interest is brought to the thermal and mechanical characteristics, which constitute a decisive character for the choice of a building material. A series of earthen samples stabilized at 5% and reinforced with DPF of various fiber weight fractions, (5%, 10%), were manufactured and compacted applying two levels compacting, (5MPa and 10MPa). Compressive strength and thermal conductivity were experimentally studied; heating capacity and diffusivity were indirectly calculated. It was found that the fibrous reinforcement proved thermal conductivity and compressive strength. it also enhanced thermal performances. Thus, the results found allow us to investigate hygrothermal behaviour and its impact on occupants comfort.Recently, some cheap materials are available and adaptable to climate seem to meet current requirements. This paper investigates the thermal and mechanical properties of cement stabilized earth bricks(CSEB) reinforced with date palm fibers (DPF). The main goal is to develop and expand the field of use of these materials in the construction sector, and investigate the possibility of new bio composite as renewable, insulating building material with low cost, made of earth and reinforced with palm wood waste. In this study, a particular interest is brought to the thermal and mechanical characteristics, which constitute a decisive character for the choice of a building material. A series of earthen samples stabilized at 5% and reinforced with DPF of various fiber weight fractions, (5%, 10%), were manufactured and compacted applying two levels compacting, (5MPa and 10MPa). Compressive strength and thermal conductivity were experimentally studied; heating capacity and diffusivity were indirectly calculated. It ...

Over the past decades the piston is designed to transfer force to the crank shaft through a piston rod by the expansion of gases in the cylinder. During working piston has to tolerate the cyclic gas pressure and the inertial forces, due to which the piston experiences fatigue damages such as piston side wear, piston head cracks and so on. Earlier pistons were made up of cast iron or aluminium due to their lightweight and high heat transfer rate. After some experiments it was noted that on heating cast iron expands due to which it covers the clearance level that comes to seize the engine. This paper aims to design a piston using composite material such as Al-GHS 1300, Al-GHY 1250, Al-Si-C, A6061 and A4032 that will differ the material and the characteristics of the traditional engine piston. This paper describes the thermal and mechanical properties of the piston when the study is done by taking five different materials.