Raw Material Size Research Articles

Potential Use of Phoenix canariensis Biomass in Binderless Particleboards at Low Temperature and Pressure

Binderless particleboards of Phoenix canariensis were manufactured by hot pressing at a low temperature (120 °C) and low pressure (2.6 MPa). Nine different configurations were analyzed to study different palm tissues. The experimental panels were tested for their mechanical and physical properties according to the procedures defined by the European Union (EN) standards. The microstructure of the raw material was investigated by scanning electron microscopy (SEM) equipped with an energy dispersive X-ray detector for microanalysis (EDXA). The physical and mechanical behavior seemed to be influenced by the amount of parenchymatous tissue. Raw material and particle size have a profound effect on the board properties. The mechanism of self-bonding could have resulted from the high content of sugars, which were partly transformed into furfural. The use of this waste material could be beneficial to the environment because it is a method of carbon fixation, helping to decrease atmospheric CO2.

PENGARUH SUHU, WAKTU, DAN KADAR AIR BAHAN BAKU TERHADAP PIROLISIS SERBUK PELEPAH KELAPA SAWIT


 Palm plantation produce waste in form of palm midribs in large number. One of the way to handle and increase the value of palm midrib waste is by pyrolysis. The particle size of raw material that used in this study was 23 – 50 mesh. The reduction of raw material size can increase the heating rate of pyrolysis. This study aimed to analyze the effect of temperature, time, and water content of raw material on the yield and pH of liquid smoke. Pyrolysis of palm midrib powder was processed at 150 oC, 200 oC, and 250 oC with various time was 30 minutes, 60 minutes, and 90 minutes. The study found that the yield of liquid smoke tend to increase with rising pyrolysis temperature and time until the condition when un-condensable gas was produced more so that the increase of pyrolysis temperature and time will further decrease the yield. The highest yield of liquid smoke obtained at 250 oC for 30 minutes, is 20,69%. The best pH of liquid smoke obtained at pyrolysis temperature 250 oC for 90 minutes, is 2,6.

PENGARUH UKURAN PARTIKEL, WAKTU DAN SUHU PADA EKSTRAKSI FENOL DARI LENGKUAS MERAH

Galangal is one of spices containing phenol. This study aims to product phenol in a liquid phase from galangal. The variations performed in this study involve the time of extraction (3 hours, 6 hours, 9 hours), temperature (30 oC, 45 oC, 60 oC) and particle size of raw material (70 mesh, 100 mesh, 140 mesh). One of the analysis in this study is the yield of phenol. The highest phenol in this study is about 4,5%. This result is obtained using 140 mesh of tray at 60°C of temperature and 9 hours of extraction time.

Influence of beneficiated sinter grade iron ore fines size on sinter productivity and quality

The iron ore sinter structure and its physical and metallurgical properties mainly depend on the raw material chemistry, size, size distribution and sintering process parameters. Pot grate sintering studies have been carried out on iron ore fines of different sizes like –3 mm (mean size 1.46 mm), –6 mm (Mean size 1.95 mm), –8 mm (mean size 2.20 mm), and –10 mm (mean size 2.63 mm) to study the influence of iron ore fines feed size on granulation, sinter bed permeability, sinter mineralogy, sinter physical and metallurgical properties. The experimental iron ore fines consist of –150micron size 14.5 to 15.2% and coarser size was maintained from 10 to 3 mm size. The results showed that sinter with mean particle size 2.20 mm (–8 mm size) showed higher productivity due to better granulation and sinter bed permeability and good physical (strength) and metallurgical (RDI and reducibility) properties due to the formation of high strength acicular SFCA phase with fine porosity. The sinter with iron ore fines mean particle size 2.63 mm showed physical and metallurgical properties within the acceptable range, which is required for blast furnace operation. Sinter with mean particle size 1.49 and 1.95 showed poor sinter strength, RDI and productivity due to poor sinter granulation and sinter bed permeability. Iron ore fines size less than 6 mm and 3 mm was not suitable for sinter making to achieve better granulation and sinter properties.

A Three-Layer Supply Chain EPQ Model for Price- and Stock-Dependent Stochastic Demand with Imperfect Item Under Rework

In this paper, we have developed an integrated supplier-manufacturer-retailer, joint economic lot-sizing model for the items with stochastic demand and imperfect quality. The supplier produces the item (raw material) up to certain time, which is a decision variable, and sends it to the manufacturer. Now, the manufacturer produces the item in small cycles and the production process of manufacturer is imperfect which produces certain number of defective items. A 100 % screening process for detecting the imperfect quality items is conducted, and at the end of each cycle, the imperfect items are accumulated and are reworked by the manufacturer. Thus, ultimately the retailer receives the perfect quality item. We consider that the delivery quantity to the retailer depends on the price and stock-dependent stochastic demand of the retailer. The model considers the impact of business strategies such as optimal time, optimal ordering size of raw material, production rate, etc. in different sectors on collaborating marketing system. An analytical method is applied to optimize the production time and production rate to obtain minimum total cost. Finally, numerical results, which have several interesting managerial insights and implications, and the sensitivity analysis are presented and discussed for illustrative purposes.

Extracting xylooligosaccharides in wheat bran by screening and cellulase assisted enzymatic hydrolysis

Functional xylooligosaccharides (XOS) from wheat bran were carried out by screening and cellulase assisted enzymatic hydrolysis. First, wheat bran was crushed and screened, getting the optimal experimental particle size of raw materials (>125μm), and 72.43% of starch. Wheat bran was then repeated colloid milled and hydrolysed with cellulase, releasing about 45% of xylan (higher than the untreated wheat bran (about 29%)). Finally, membrane treatment (20kDa and 1kDa cutoff) was chosen to eliminate impurities and enriched XOS. In the designed process, 51mg purified XOS was obtained from 1g dry wheat bran powder.

Determination of reaction areas for the sulfur conversion during low-metamorphosed coal oxidative desulphurization

Taken into account the global trends of metallurgy, in order to save energy, new technologies in blast furnaces are actively developed in Ukraine, namely, substitution of natural gas for pulverized coal (PC). However, use of this technique is complicated by inconsistencies of characteristics of a large part of domestic coal with requirements that apply to PC raw materials, primarily because of the high sulfur content in it.To solve this problem, it is proposed to use the method of coal oxidative desulphurization that consists in selective conversion of pyritic sulfur by vapor-air mixture. However, the content of sulfur in coal is not the only requirement, so the task of research is determination of process parameters that will enable to minimize the destruction and burning of organic carbon that occurs during its oxidative desulphurization.Series of experiments on detailed determination of patterns for high-sulfur low-metamorphosed coal oxidative desulphurization to produce raw materials for PC are began in this article. The effect of linear velocity of the oxidant and the grain size of raw materials on the process is determined and the values of these factors when oxidative desulphurization isn't limited to diffusion velocity of the oxidant to the coal grain surface are established. The dependence of the process stages from parameters of fluidized bed and mass transfer criteria of the reagent is shown.

The influence of raw material size on stone artefact assemblage formation: An example from Bone Cave, south-western Tasmania

This paper specifically examines the influence of raw material size on stone artefact assemblage formation in conjunction with two behavioural assemblage formation processes: reduction intensity and artefact transport. The aim is to establish whether raw material size can influence the way in which reduction intensity and artefact transport form a stone artefact assemblage and, should a significant influence be established, whether this has any bearing on human behavioural reconstructions. This is first investigated in an experimental setting followed by an archaeological setting using a quartzite and chert assemblage from Bone Cave in south-western Tasmania. Reduction intensity and artefact transport are respectively measured using the scar density index, flake to core ratio, non-cortical to cortical flake ratio and cortex ratio while tool blank sizes are also reconstructed. The combined experimental and archaeological analyses find that raw material size variation is capable of exerting a substantial influence on stone artefact assemblage formation. This particularly with reference to the nature of change in stone artefact assemblages: both reduction intensity and artefact transport will alter assemblage composition at faster rates when nodule sizes are smaller. This can have significant implications for intra- and inter-site reconstructions of past human behaviour.

Location Pattern of Unorganised Manufacturing Industries in India: A District-level View

This article examines the location pattern of unorganised manufacturing enterprises across districts in India. Using a unique data set of 435 districts spread across 25 states, drawn from the Enterprise Survey data of the National Sample Survey (NSS) 1994–95 and 2005–06 ‘thick’ rounds, we find that unorganised manufacturing enterprises are concentrated in a few leading districts, mostly in the metropolitan areas, but their share has declined in the post-reform (post-1991) period, and some new metropolises and suburban districts have emerged as new industrial destinations. The spatial concentration in the distribution of the unorganised manufacturing enterprises across districts has marginally declined—both at the aggregated and disaggregated industry level—in the post-reform period. Our econometric analysis shows that the level of economic development, infrastructure facilities, labour productivity, capital productivity, population size, population density, availability and stock of raw materials, presence and size of organised industries and urbanisation have significant positive effects on the location of unorganised manufacturing enterprises, while economic diversity has a strong negative impact. The specificity of our study is that we use district-level data, which allows us to provide a relatively comprehensive view of the location pattern of unorganised manufacturing enterprises in India. JEL Classification: R12, R58, L5, L6

Isothermal kinetic analysis of the effects of high-energy ball milling on solid-state reaction of Li4Ti5O12

The effects of high-energy ball milling on the solid-state reaction were determined by X-ray diffractometry, scanning electron microscopy, and activation energy calculation, respectively. Isothermal kinetic analysis of solid-state reaction of Li4Ti5O12 was studied using an isothermal thermogravimetric tests. The results indicate that the anatase to rutile transformation of TiO2 and formation of Li4Ti5O12 occur at a lower temperature, because the particle size of raw materials reduced by high-energy ball milling. In contrast to Jader equation, the model based on Johnson–Mehl–Avrami equation shows better linear fitting within temperature interval from 450 to 550°C. The value of the kinetic parameter m is approximate to 0.4, indicating that the formation of products could be a diffusion controlled mechanism. Meanwhile, the activation energy of solid-state reaction decreases from 119.4 to 95.2kJ/mol after high-energy ball milling. Electrochemical tests show that Li4Ti5O12 samples synthesized by high-energy ball milling exhibit better rate capacity and cycle performance.

Study on the synthesis behavior of Fe–W–B powders and the preparation of bulk

FeWB alloy powders were successfully produced by reactive synthesis. In this paper, effects of particle size of raw materials on the synthesis behavior of FeWB alloy powders were systematically investigated and powders with a high density of 13.99g/cm3 were fabricated into bulk materials by Spark Plasma Sintering (SPS) technique. Both W and FeB with varying particle sizes ranging from 3μm to 15μm were used as raw materials to prepare FeWB alloy powders. Microstructural analysis was performed using X-ray diffraction (XRD), scanning electron microscopes (SEM) equipped with an energy dispersive spectroscopy (EDS), and Mössbauer spectrometry at room temperature. Mean particle sizes were determined by laser granulometry. The results showed that particle size of raw materials had noticeable influence on both microstructure and amount of the resultant FeWB powders. Hardness of the bulk materials was measured by HR-150A Rockwell hardness tester. It had been significantly enhanced and reached 91.8 HRA, which could be comparable to that of cemented carbides.

Simultaneous Multifunctional Sorption of PFOS and Cr(VI) on Activated Carbon Prepared by One-Step Microwave Activation

Multifunctional sorbents, activated carbons (AC), were prepared by one-step microwave activation utilizing peanut shells and sunflower seed husks. The influence of the original particle size of raw materials on the yield and specific surface area of AC was studied, which reached 33.5 % and 1133.27 m2/g, respectively. The repetitive and competitive uptakes of perfluorooctane sulfonate (PFOS) and chromium were applied to investigate the sorption properties of AC. The sorption mechanisms were demonstrated using sulfur K-edge X-ray absorption near edge structure analysis (XANES). In the repetitive experiment, AC made from peanut shells (ACP05) still retained 70 % removal efficiency of PFOS after the fourth sorption because sorbed PFOS might form a new organic phase that supplied effective sites for the hydrophobic partition of PFOS. However, the removal efficiency of Cr(VI) decreased dramatically from 60 to 11 % after the fourth uptake because electrostatic attraction was its only removal pathway. In the binary solutes system, ACP05 possessed perfect sorption performance for both PFOS and Cr(VI), which were 885 and 192 mg/g, respectively. In the multivariate solutes system, the XANES spectra indicated that the thiol functional group existed in the resulting AC and a metal chelate was formed between thiol and Zn2+/Cu2+. Hence, the presence of Zn2+/Cu2+ further promoted the removal of PFOS and Cr(VI) through the electrostatic attraction between the anions and positive metal chelate.

Optimization of the optical properties of α-SiAlON through a decrease in starting powder size

In the present work, the effects of initial powder size on the sintering behavior and optical properties of Dy-α-SiAlON ceramics produced by the SPS technique are investigated. The powders were prepared using high energy and conventional milling processes to make comparisons. The powders, prepared by conventional processes, were used as a standard. After sintering, the infrared transmittance behavior of the SiAlON ceramics was investigated in a wavenumber range of between 7000 and 1000cm−1 using an FTIR. The microstructure and phase characterization of the samples were carried out using an SEM and the XRD method, respectively. It was observed that the secondary crystalline phases, the sizes of grains and the distribution of the glassy phase around the grains were the main factors that affected the transmittance of the samples. As a result, it was shown that the starting particle size of raw materials had a significant effect on the microstructure and optical properties of the samples.

Integrated quality strategy in production and raw material replenishment in a manufacturing-oriented supply chain

This paper deals with the coordination of production, replenishment and inspection decisions for a manufacturing-oriented supply chain with a failure-prone transformation stage, random lead time and imperfect delivered lots. Upon reception of the lot, the manufacturer executes an acceptance sampling plan with a zero non-conforming criterion. If the sample does not contain non-conforming items, the lot is accepted; otherwise, it is rejected. In this work, two strategies regarding the refused sampled lot are studied. The first one involves a return of the lot to the supplier, who commits to improving the quality of the lot, while the second assumes that the manufacturer performs a 100 % inspection and rectification operation. This work presents two main objectives. The first one is to jointly optimize, in a stochastic and dynamic context, the ordering point of raw material, the lot size of raw material, the final product inventory threshold and the severity of the sampling plan using a simulation-based optimization approach. The second one is to determine the best of the two quality control strategies. The in-depth study has shown that no strategy could be preferred in all the cases. For this reasons, we present an easy decision-making tool (indifference curves) to help the manager select the best quality control strategy when considering the entire supply chain.

Interaction between Kaolin and Urea in Organoclay and Its Impact on Removing Methylene Blue from Aqueous Solution

Interaction between kaolin (particle size 53 and 106 μm) and urea was studied by infrared spectroscopy and powder X-ray diffraction. Interaction was found to be dependent on the particle size of kaolin raw material. Nature of interaction achieved through the formation of hydrogen bonds between urea and both AlOH and Si-O surface of kaolinite. Effect of temperature on equilibrium adsorption of methylene blue (MB) from aqueous solution using kaolin also studied, the results were analyzed by Langmuir and frendlich isotherms. Thermodynamic parameters such as ΔG, ΔH and ΔS were calculated. Results suggested that the MB adsorption on kaolin was spontaneous and exothermic process.

Integrated production inventory model: multi-item, multiple suppliers and retailers, exponential demand rate

In this paper, an integrated production-inventory model with multi-item is developed from the perspectives of single producer, multiple suppliers and retailers. In this three-layer supply chain, the retailers are non-competing. Every supplier delivers only single type of raw material to the producer. The producer manufactures finished goods from the combination of fixed percentage of different types of raw materials. The producer manufactures various types of objects and supplies them to retailers according to the demand of multiple retailers. This paper studies the impact of different types of business policies such as exponential demand rate, demand dependent production rate, optimum order size of raw materials, and unit production cost at each stage of integrated marketing system. Mathematica is used to develop the model and to optimize the integrated profit function. A numerical example and sensitivity analysis is illustrated to justify the feasibility of the proposed model.

H2O2 Oxidation of Corncob Holocellulose as a Dry-strength Additive for Paper

Corncob, an underutilized agricultural byproduct, was used as the raw material to make a dry-strength additive for paper. Corncob was ground into 80, 100, 150, and 200 mesh powder. The powder was treated with sodium chlorite to remove lignin, and the resulting holocellulose was modified with hydrogen peroxide. The influences of oxidation time, concentration of hydrogen peroxide, dosage of paper strength agent, and the dosage of aluminum sulfate on the paper properties were studied. The results indicate that the oxidized corncobs holocellulose can improve the tensile index, burst index, and folding endurance of paper. Compared with control paper, when the concentration of hydrogen peroxide was 0.9%, the tensile index, burst index, and folding endurance were increased by 24.2%, 14.1%, and 463.8%, respectively. The particle size of raw material, dosage of strengthening agent or aluminum sulfate greatly influences paper properties. Scanning electron microscopy (SEM) analysis showed that the combination between the fibers was improved after adding the strengthening agent, thus improving the strength of the paper. The results can provide a new method for value-added use of corncob.

Influence of particle size on sinterability, crystallisation kinetics and flexural strength of wollastonite glass-ceramics from waste glass and fly ash

Wollastonite glass-ceramics were prepared from waste glass and fly ash by using the primary powder sintering. The sinterability, crystallisation kinetics and mechanical property of glass-ceramics have been investigated systematically with respect to the influence of particle size of raw materials. As compared to coarse powders (44 μm), fine powders (6 μm) exhibited fast sintering rate, high densification and high degree of crystallinity. The sintering kinetic analysis showed that the sintering activation energies were 229 and 157 kJ mol−1 for coarse and fine powders respectively, in well agreement with those from the linear shrinkage analysis. The activation energies of crystallisation were 245 and 317 kJ mol−1 for coarse and fine powders, respectively, suggesting high energy barrier of crystallisation for fine powders. The flexural strengths of wollastonite glass-ceramics from fine powders were increased by more than 50% as compared to that from coarse powders, resulting from the improved densification, high degree of crystallinity and crystal shape anisotropy as well as crystal refinement.

Three-layer supply chain in an imperfect production inventory model with two storage facilities under fuzzy rough environment

Abstract This article focuses on an imperfect production inventory model considering product reliability and reworking of imperfect items in three-layer supply chain under fuzzy rough environment. In the model, the supplier receives the raw materials, all are not of perfect quality, in a lot and delivers the items of superior quality to the manufacturer and the inferior quality items are sold at a reduced price in a single batch by the end of the cent percent screening process. The manufacturer produces a mixture of perfect and imperfect quality items. A portion of the imperfect items is transformed into perfect quality items after rework. Another portion of imperfect items, termed as `less perfect quality items', is sold at a reduced price to the retailer, and the portion which cannot be either transformed to the perfect quality items or sold at a reduce price is being rejected. Here, retailer purchases both the perfect and imperfect quality items from the manufacturer to sell the items to the customers through his/her respective showrooms of finite capacities. A secondary warehouse of infinite capacity is hired by the retailer on rental basis to store the excess quantity of perfect quality items. This model considers the impact of business strategies such as optimal order size of raw materials, production rate, and unit production cost in different sectors in a collaborating marketing system that can be used in the industry, like textile, footwear, and electronics goods. An analytical method has been used to optimize the production rate and raw material order size for maximization of the average profit of the integrated model. Finally, a numerical example is given to illustrate the model.

Measuring stone artefact transport: the experimental demonstration and pilot application of a new method to a prehistoric adze workshop, southern Cook Islands

This paper presents a new method, based on the calculation of a Cortex Ratio, capable of contributing towards measures of stone artefact transport in Polynesia. A set of ratios can be calculated by comparing the observed amount of cortical surface area and volume in an assemblage with what is expected should all the products of reduction remain. Because raw material shape and size is controlled for using geometric equations, an estimate for the number of preforms produced from an assemblage also is possible. The method is experimentally demonstrated and applied to an archaeological early stage adze manufacturing assemblage from Moturakau Rockshelter, Aitutaki Island in the southern Cook Islands. Application of the method, in combination with geochemical and chronological analyses, shows that the number of preforms produced and transported, as well as the frequency of their transport, changed over time but the geographic scale of distribution remained the same, essentially local to Aitutaki.