scholarly journals Preparation of Nanocellulose Aerogel from the Poplar (Populus tomentosa) Catkin Fiber

Forests ◽  
2019 ◽  
Vol 10 (9) ◽  
pp. 749 ◽  
Author(s):  
Wu ◽  
Sun ◽  
Wu ◽  
Shi ◽  
Chen ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Elastic Modulus ◽  
Honeycomb Structure ◽  
Populus Tomentosa ◽  
Raw Material ◽  
Sodium Chlorite ◽  
Maximum Value ◽  
Ultrasonic Time ◽  
Naoh Solution ◽  
The Difference

: The effects of chemical pretreatment on the purification of poplar (Populus tomentosa) catkin fiber and the effect of ultrasonic time for the microfibrillarization of poplar catkin fiber (PCF) were studied. The nanocellulose aerogels were prepared by freeze drying the cellulose solutions. The density, porosity, micro morphology, thermal stability and mechanical properties of the aerogels were analyzed. It was found that the dewaxing time of PCF is shorter than that of unsonicated nanocellulose. After the treatment of 0.5 wt% sodium chlorite for 2 h, the lignin of PCF was removed. After the chemical purification, the PCF was treated with 2 and 5 wt% NaOH solution and ultrasonicated for 5 and 10 min, respectively. When the ultrasonic time was 10 min, the diameter of the nanocellulose was 20-25 nm. When the ultrasonic time was 5 min, the aerogels with porous honeycomb structure can be prepared by using the nanocellulose sol of PCF as raw material. The density of the aerogels was only 0.3-0.4 mg/cm3 and the porosities of the aerogels were all larger than 99%. The difference between the pyrolysis temperature of aerogels was small, the elastic modulus of aerogels was 30–52 kPa, and the compressive strength was 22–27 kPa. With the increase of the concentration of NaOH solution (5 wt%) and ultrasonic time (10 min), the elastic modulus of aerogels increased gradually and reached the maximum value of 52 kPa, while the compressive strength reached the maximum value of 27 kPa when the PCF being treated in 5 wt% NaOH solution and was ultrasonicated for 5 min.

scholarly journals PEMANFAATAN LIMBAH FLY ASH DARI PEMBAKARAN BATUBARA PADA PEMBUATAN SEMEN PCC (PORTLAND COMPOSITE CEMENT) DI PT SEMEN XYZ LAMPUNG

2020 ◽  
Vol 4 (2) ◽  
Author(s):  
Dwi Septiyana Sari ◽  
◽  
Susanti Sundari
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Raw Materials ◽  
Testing Machine ◽  
Technical Aspect ◽  
Raw Material ◽  
Physical Test ◽  
Composite Cement ◽  
The Difference ◽  
The Cost

Abstract This study discusses the use of fly ash waste from coal burning on the manufacture of PCC (Portland composite cement) at PT. XYZ Lampung. The purpose of this research is to look at the technical studies and the efficiency of raw materials in the use of fly ash in cement making, in this case PCC cement (Portland Composite Cement). The steps taken in analyzing the data in this study were viewed from a technical aspect by means of a physical test, namely the cement compressive strength test at the age of 3 days, 7 days, and 28 days using the Compression Testing Machine. This test was conducted to see the comparison of the compressive strength of PCC cement using limestone and fly ash as raw materials, then calculate the difference in raw material costs in the year before and after the replacement of limestone with fly ash. The results showed that cement with the addition of fly ash after 3 days, 7 days and 28 days had an increased compressive strength value, which increased 21.69%, 16.07% and 8.05% respectively of the compressive strength of cement using limestone. The use of fly ash as a substitute for limestone has an effect on the cost of raw materials, where the difference between the cost of raw materials in 2019 and the cost of raw materials in 2018 is Rp. 39,440,952,074.

Effect of Cement Content and Curing Period on Properties of DUT-1 Synthetic Model Ice

2003 ◽  
Vol 125 (4) ◽  
pp. 288-292 ◽  
Author(s):  
Zhijun Li ◽  
Yongxue Wang ◽  
Xiwen Wang ◽  
Guangwei Li
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Elastic Modulus ◽  
Cement Content ◽  
Physical And Mechanical Properties ◽  
Dry Weight ◽  
Mechanical Parameters ◽  
Synthetic Model ◽  
Curing Period ◽  
Maximum Value

The effects of cement content and curing period on a new synthetic model ice, DUT-1, are reported. The cement (450#) contents were 10%, 11%, 12%, 13%, 14%, 15% and 16% by dry weight of mixture material. Eight different curing periods were used: 66 h, 92 h, 115 h, 139 h, 163 h, 186 h, 211 h and 235 h. Physical and mechanical properties, such as density, compressive strength, flexural strength, and elastic modulus, were determined. The density and mechanical parameters were found to increase with increasing cement content, whereas the durations of curing period under normal air temperature resulted in increasing these properties to a maximum value, then decreasing values.

scholarly journals Cellulose Nanocrystal (CNC) Capsules from Oil Palm Empty Fruit Bunches (OPEFB)

2021 ◽  
Vol 12 (2) ◽  
pp. 2013-2021
Keyword(s):  
Sulfuric Acid ◽  
Elastic Modulus ◽  
Oil Palm ◽  
Maximum Yield ◽  
Raw Material ◽  
Cellulose Nanocrystal ◽  
Disintegration Time ◽  
Gelatin Capsules ◽  
Empty Fruit Bunches ◽  
Naoh Solution

The raw material used for this NCC production was oil palm empty bunches (OPEFB), currently waste from oil palm plantations. Delignification of OPEFB was carried out using 2 N NaOH solution at 70oC for 6 hours. NCC maximum yield from OPEFB is 62.1% (dry cellulose basis) obtained at a concentration of 54% sulfuric acid and a temperature of 50oC. The addition of plasticizers (glycerol and PEG) reduced the elastic modulus of NCC capsules from 7951.4 MPa to 4758 MPa (glycerol) and 3225 (PEG). The addition of glycerol and PEG did not affect the disintegration time of NCC capsules. NCC capsules have a release capability similar to the commercially available gelatin capsules. At 14 minutes, discharge reached about 43%, and it becomes constant after 18 minutes.

Use of Concrete Wastes in Concrete Paving Blocks by Thermal-Mechanical Separation

2011 ◽  
Vol 374-377 ◽  
pp. 1303-1306
Author(s):  
Qing Bo Tian ◽  
Li Na Xu ◽  
Li Yang ◽  
Xiu Hui Wang ◽  
Hong Gao
Keyword(s):  
Compressive Strength ◽  
Active Material ◽  
Critical Value ◽  
Raw Material ◽  
Test Results ◽  
Water Addition ◽  
Steam Curing ◽  
Mechanical Separation ◽  
The Difference ◽  
Water Amount

A concrete paving blocks was produced using pretreated concrete wastes as main raw material by pressure forming and steam-curing at 70°C. The test results showed that with the increase of water addition, the paving blocks increase its strength. And as the additions of water amount reach to a critical value, the compressive strength has an adverse change and decreased. As the rise of ratio of cement and wastes, the compressive strength also increases. The difference in various ratios of cement and wastes is that the difference of water needed as the compressive strength achieved its highest value. The thermal treatment temperatures has greatly influence on the compressive strength. The increments of thermal-treated temperatures induce the active material to form and cause the particle grading more reasonable in the concrete wastes, which is benefit to the shaping of specimen and increasing of strength. The maximum compressive strength of 53.2 MPa is obtained in the mixture thermal-treated at 800°C by adjusting the water additions.

scholarly journals Effect of Absorbent Foam Filling on Mechanical Behaviors of 3D-Printed Honeycombs

Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2059
Author(s):  
Leilei Yan ◽  
Keyu Zhu ◽  
Yunwei Zhang ◽  
Chun Zhang ◽  
Xitao Zheng
Keyword(s):  
Compressive Strength ◽  
Elastic Modulus ◽  
Energy Absorption ◽  
Unit Volume ◽  
Honeycomb Structure ◽  
Unit Mass ◽  
Out Of Plane ◽  
Foam Filling ◽  
3D Printed ◽  
Foam Filled

Polylactic acid (PLA) hexagonal honeycomb structures were fabricated by using 3D-printing technology. By filling with absorbent polymethacrylimide (PMI) foam, a novel absorbent-foam-filled 3D-printed honeycomb was obtained. The in-plane (L- and W-direction) and out-of-plane (T-direction) compressive performances were studied experimentally and numerically. Due to absorbent PMI foam filling, the elastic modulus, compressive strength, energy absorption per unit volume, and energy absorption per unit mass of absorbent-foam-filled honeycomb under L-direction were increased by 296.34%, 168.75%, 505.57%, and 244.22%, respectively. Moreover, the elastic modulus, compressive strength, energy absorption per unit volume, and energy absorption per unit mass, under W-direction, also have increments of 211.65%, 179.85, 799.45%, and 413.02%, respectively. However, for out-of-plane compression, the compressive strength and energy absorption per unit volume were enhanced, but the density has also been increased; thus, it is not competitive in energy absorption per unit mass. Failure mechanism and dimension effects of absorbent-foam-filled honeycomb were also considered. The approach of absorbent foam filling made the 3D-printed honeycomb structure more competitive in electromagnetic wave stealth applications, while acting simultaneously as load-carrying structures.

scholarly journals Manufacture of fiber composite materials musa acuminate l. prepared by the randomized position with polymer matrix resin

2018 ◽  
Vol 154 ◽  
pp. 01006 ◽  
Author(s):  
Lailan Ni’mah ◽  
M. Rizka Akbari ◽  
Ferdi Akhmad Khan ◽  
M. Afief Ma’ruf
Keyword(s):  
Tensile Test ◽  
Fiber Composite ◽  
Raw Material ◽  
Matrix Resin ◽  
Banana Fiber ◽  
Pressure Tests ◽  
Pressure Test ◽  
Naoh Solution ◽  
The Difference ◽  
Fiber Composite Materials

Composite is a system composed by mixing two or more different materials, in the form and composition of materials that do not dissolve each other. In general, the composite material is a material that has some properties that may not be owned by each component. This study aims to determine the effect of immersion banana fiber in NaOH solution, the composition ratio of the difference between the banana fiber to resin used and find the resistance of composite products produced against the pressure test and tensile test. This study begins with taking fiber banana followed by delignification process to remove lignin in the raw material, then molding composites made with a composition that has been set. The resulting composite will be tested durability to perform pressure tests (ASTM D 695) and a tensile test (ASTM D 638). To test tap on the position of the randomized to the concentration of NaOH 0%, 3%, 5% and 7% respectively, each for 53.716 N/mm 2, 43.184 N/mm 2, 81.724 N/mm 2 and 30.032 N/mm 2. For tensile test on an randomized position with NaOH concentration of 0%, 3%, 5% and 7% respectively, each for 21.519 M.Pa, 18.359 M.Pa, 31.033 M.Pa and 21.064 M.Pa.

scholarly journals Geopolymers Based on Mechanically Activated Fly Ash Blended with Dolomite

Minerals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 700
Author(s):  
Alexander M. Kalinkin ◽  
Basya I. Gurevich ◽  
Elena V. Kalinkina ◽  
Mikhail V. Chislov ◽  
Irina A. Zvereva
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Mechanical Activation ◽  
Raw Material ◽  
Early Age ◽  
X Ray Diffraction ◽  
Simple Method ◽  
X Ray ◽  
Alkaline Agent ◽  
Naoh Solution

This study reports the effect of natural dolomite addition to fly ash and the mechanical activation of this blend on the geopolymerization process. Dolomite was replaced with fly ash at 1, 3, 5, and 10 wt.%. Geopolymers were synthesized at ambient temperature using NaOH solution as an alkaline agent. The geopolymerization process, reactivity of the raw material, compressive strength, and microstructure were studied using X-ray diffraction, Fourier-transform infrared spectroscopy, thermogravimetry, and scanning electron microscopy. It was shown that blending fly ash with dolomite and mechanical activation improved the geopolymer strength, especially during the early age of curing. For geopolymers prepared using a 90% fly ash + 10% dolomite blend cured for 7 d, the strengths were 8.2-, 2.3-, and 1.4-fold higher than those for geopolymers prepared using 100% FA for 30 s, 180 s, and 400 s milling times, respectively. A simple method for evaluating the increments of mechanical activation, carbonate additives, and the synergistic effect in the increase in the compressive strength of the composite geopolymer is proposed.

scholarly journals Experimental Study on the Durability of Alkali-Activated Slag Concrete after Freeze-Thaw Cycle

2021 ◽  
Vol 2021 ◽  
pp. 1-19
Author(s):  
Bin Chen ◽  
Jun Wang
Keyword(s):  
Compressive Strength ◽  
Elastic Modulus ◽  
Raw Material ◽  
Dynamic Elastic Modulus ◽  
Important Indicator ◽  
Alkali Activated Slag ◽  
Freeze Thaw ◽  
Thaw Cycle ◽  
Activated Slag ◽  
Alkali Activated

A freeze-thaw resistance is an important indicator of the durability of alkali-activated slag concrete, which causes structural failure when the performance is low, especially in severely cold areas. In this study, solid sodium aluminate and sodium silicate were used as composite alkaline activators, while slag was used as the raw material to prepare alkali-activated slag concrete, whose freeze-thaw resistance, as well as that of ordinary cement concrete, was experimentally studied by varying the freeze-thaw cycles. The effects of the mass, compressive strength, and dynamic elastic modulus of the sample were investigated by considering the influence of different water-to-slag ratios and slag contents, while the damage variables and model were also analyzed. The results showed that alkali-activated slag concrete had an excellent freeze-thaw resistance, which was significantly affected by the water-to-slag ratio and compressive strength; specifically, the higher the water-to-slag ratio, the lower the freeze-thaw resistance, and the higher the compressive strength, the better the freeze-thaw resistance. The freeze-thaw durability, microstructure, and damage mechanism were studied via microscopic analysis. When analyzed via the microstructure test, crack pores and microcracks with narrow spaces and large surface areas were generated under freeze-thaw damage conditions, but the dense hydration structure and high-bonding-strength hydration products led to a better freeze-thaw resistance. The damage model was established using compressive strength and relative dynamic elastic modulus as damage variables, and the attenuation exponential and accumulative damage power function model had a high accuracy, which could better reflect the freeze-thaw damage law and damage degree and predict the lifetime of alkali-activated slag concrete.

scholarly journals Experimental Study on the Difference of Shale Mechanical Properties

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Qi Liu ◽  
Bing Liang ◽  
Weiji Sun ◽  
Hang Zhao
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Elastic Modulus ◽  
Wave Velocity ◽  
Poisson’S Ratio ◽  
Failure Modes ◽  
High Stress ◽  
Poisson's Ratio ◽  
Bedding Angle ◽  
The Difference

This paper studies the anisotropic characteristics of shale and the difference in mechanical performance between deep shale and outcrop shale. The outcrop shale was collected from the Shuanghe section in Changning County, southern Sichuan, and the deep shale was collected from the Wells Yi201 and Lu202. Study their basic mechanical parameters, failure modes, and wave velocity responses through laboratory tests. Research shows that with the increase of bedding angle, the deformation mode has the trend from elastic deformation to plastic deformation in high-stress state. When the bedding angles are 0°, 30°, and 45°, the weak bedding surface plays a leading role in the formation of the failure surface trend. As the bedding angle increases to 60° and 90°, its influence is weakened. The tensile strength, elastic modulus, and wave velocity decrease with the increase of bedding angle. The compressive strength and Poisson’s ratio have the law of U-type change, there are higher values at 0° and 90°, and the lowest values are at 30°. The brittleness index first increases and then decreases with the increase of the bedding angle. The tensile strength and Poisson’s ratio of outcrop shale and deep shale are close, but the compressive strength of deep shale is only 1/3 of outcrop shale, the elastic modulus is only 3/4 of outcrop shale, and the failure of deep shale is accompanied by instability failure.

SELISIH BIAYA PRODUKSI SEBAGAI ALAT PENGENDALIAN MANAJEMEN PT INDO PUSAKA BERAU

2019 ◽  
Vol 3 (02) ◽  
pp. 397
Author(s):  
SAFITRI NURHIDAYATI ◽  
RIZKI AMELYA SYAM
Keyword(s):  
Raw Materials ◽  
Field Research ◽  
Analytical Tool ◽  
Production Costs ◽  
Raw Material ◽  
Labor Costs ◽  
Material Costs ◽  
Library Research ◽  
The Difference ◽  
The Cost

This study aims to analyze whether the difference that occurs in the cost of raw materials, direct labor, and factory overhead costs between the standard costs and the actual costs in PLTU LATI is a difference that is favorable or unfavorable. Data collection techniques with field research and library research. The analytical tool used is the analysis of the difference in raw material costs, the difference in direct labor costs and the difference in factory overhead costs. The hypothesis in this study is that the difference allegedly occurs in the cost of raw materials, direct labor costs, and factory overhead costs at PT Indo Pusaka Berau Tanjung Redeb is a favorable difference. The results showed that the difference in the cost of producing MWh electricity at PT Indo Pusaka Berau Tanjung Redeb in 2018, namely the difference in the price of raw material costs Rp. 548,029.80, - is favorable, the difference in quantity of raw materials is Rp. 957,216,602, - is (favorable) , the difference in direct labor costs Rp 2,602,642,084, - is (unfavorable), and the difference in factory overhead costs Rp 8,807,051,422, - is (favorable) This shows that the difference in the overall production cost budget is favorable or profitable. This beneficial difference shows that the company is really able to reduce production costs optimally in 2018.  

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