scholarly journals effect of adding probiotic bacteria on bauxite waste mud

2022 ◽  
Vol 5 (1) ◽  
pp. 1-13
Author(s):  
Susi Hariyani ◽  
Wattini Wattini ◽  
Ida Zuraida ◽  
Pramudya Kurniawan ◽  
Lelly Marini ◽  
...  

Bauxite waste sludge is quite dangerous when polluted into the surrounding environment. The number is increasing with the higher mining production. The utilization is still not maximized hence it is unbalanced to the increasing number, and it is necessary to use on a large scale. Sub-grade soil could use a lot of bauxite waste sludge but in reality, this waste is unsafe to use and its characteristics are mud the requirements of bearing capacity according to the AASHTO and USCS Classification unfulfilled. This study aims to determine the effect of the use of probiotic bacteria in bauxite waste on its physical characteristics and pH value. This experimental research method develops test objects according to ASTM standards with the same weight of bauxite waste and variations in the number of probiotic bacteria, namely 25 ml, 50 ml, 75 ml, and 100 ml and the incubation time of bacteria is 7 days, 14 days, 21 days, 28 days, 35 days, and 42 days. The results showed that the test specimens with more bacteria and longer incubation times resulted in lower pH values and physical characteristics that fulfilled the requirements for sub-grade soil.

2021 ◽  
Vol 6 (2) ◽  
pp. 69-73
Author(s):  
Damaranie Dipahayu ◽  
Kinanti Ayu Puji Lestari

Ethanol extract of purple sweet potato (Ipomoea batatas (L.)) leaves of Antin-3 variety contains flavonoids and polyphenols which can be used as a source of acne anti-bacterial because it can inhibit the growth of Staphylococcus aureus. This study aims to obtain data on physical characteristics, acceptability and stability of anti-acne mask formulation of 70% ethanol extract of Antin-3 leaves. The research method used were characteristic, acceptability and stability test. There were 4 types of samples tested, namely base, Antin-3 extract 5%: 10% and 20% (B: F1: F2: F3). The organoleptic results showed that the higher concentration of  extract, the darker color of mask and the stronger of extract smell and the softer of consistency. The pH values ​​(B: F1:F2: F3) were respectively 6.46; 5.78; 5.75; 5.46. The value of adhesion (B: F1: F2: F3) were respectively 1.1; 1.46; 2.17 and 4.53 seconds. The value of spreading capacity (B: F1: F2: F3) were respectively 3.89; 4.15; 4.36 and 3.45 cm. The results of the acceptability test showed that F2 was the easiest formula to spread, clean and  softest sensation on the skin. The results of the mechanical  and cycling test showed that the four samples had not undergo phase separation. Anti-acne mask with 70% ethanol extract of Antin-3 leaves by 10% met the physical characteristics, acceptability and stability.


Author(s):  
Nafila Fidina ◽  
Een Sukarminah ◽  
Debby Moody Sumanti

Synbiotic yoghurt is a yoghurt with the addition of prebiotics and lactic acid bacteria (LAB) that serves as probiotic which helps to improve digestion, able to survive in gastric acid condition and able to improve immune system. The milk that was used in this study is Saneen goat milk which has higher digestibility than cow milk. The banana used in this study will be processed into puree form. The purpose of study was to determine the concentration of banana puree on synbiotic yoghurt made from goat milk and banana puree with the best microbiological, pH value, viscosity and organoleptic characteristics. The research method used was randomized block design with 4 treatments and 3 replications. Synbiotic yoghurt was made with difference concentrations of banana puree of 25%, 50%, 75% and 100%. The 50% addition of banana puree produced the best synbiotic yoghurt with 4,15 pH, 9,43 Log cfu/ml  and 9,16 Log cfu/ml total probiotic bacteria, and the organoleptic characteristics including color, flavor, taste, texture and overall appearance rather preferred by panelists.


Author(s):  
Sri Agus Murniasih And I Wayan Dirgeyasa

This study was conducted to know the effect of applying Peer Review Strategy on the students’ achievement in writing descriptive paragraph. It was conducted by using experimental research method. This research design was conducted pre-test, post test in experimental and control group. The population of this research was the eight (VIII) grade students of SMP IT IQRA’ Medan. The sample of this research was taken by lottery technique. They were in class VIII-1 by experimental group and the class VIII-2 by control group. The experimental group was taught by using Peer Review Strategy while the control group was given no treatment. The instrument used to collect the data was writing essay test. The data were analyzed by using t-test formula. The result showed that the value of t-observed was higher than the value of t-table. (3,55 > 2,05 (a = 0.05)) with the degree of freedom (df) = 28. It means that there was a significant effect of applying Peer Review Strategy on the students’ achievement in writing descriptive paragraph. So, the alternative hypothesis (Ha) was accepted.


2021 ◽  
pp. 109634802110303
Author(s):  
Hengyun Li ◽  
Fang Meng ◽  
Simon Hudson

The research aims to examine how positive review disconfirmation (i.e., a positive deviance between a hotel consumer’s poststay evaluation and the average review rating by prior consumers) affects subsequent consumers’ willingness to post online reviews and their own review ratings. By employing an experimental research method, this study reveals that positive review disconfirmation increases hotel guests’ willingness to post online reviews, and increases their online review ratings through the mechanism of concern for others, demonstrating an act of altruism. In addition, comparatively the positive review disconfirmation effects are stronger when the variance of prior review ratings is smaller. This study enhances the online review social influence literature, and the consumer’s altruistic motivation of posting online reviews.


2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Xiao Li Ma ◽  
Guang Tao Fei ◽  
Shao Hui Xu

Abstract In this study, polyaniline (PANI) is prepared by means of chemical oxidization polymerization and directly loaded on the modified fiber ball (m-FB) to obtain macroscale polyaniline/modified fiber ball (PANI/m-FB) composite, and then its removal ability of Cr(VI) is investigated. The effects of different parameters such as contact time, pH value and initial concentration on Cr(VI) removal efficiency are discussed. The experimental results illustrate that the favorable pH value is 5.0 and the maximum removal capacity is measured to be 293.13 mg g−1. Besides, PANI/m-FB composites can be regenerated and reused after being treated with strong acid. The kinetic study indicates that the adsorption procedure is mainly controlled by chemical adsorption. More importantly, the macroscale of composites can avoid secondary pollution efficiently. Benefiting from the low cost, easy preparation in large scale, environmentally friendly, excellent recycling performance as well as high removal ability, PANI/m-FB composites exhibit a potential possibility to remove Cr(VI) from industrial waste water. Graphic Abstract The polyaniline (PANI) was coated on modified fiber ball (m-FB) to remove Cr(VI) in waste water, and this kind of PANI/m-FB composites can avoid secondary pollution efficiently due to its macrostructure. Furthermore, the removal capacity can reach to 291.13 mg/g and can be multiple reused.


2020 ◽  
Vol 11 (1) ◽  
pp. 67
Author(s):  
Ján Iždinský ◽  
Ladislav Reinprecht ◽  
Ján Sedliačik ◽  
Jozef Kúdela ◽  
Viera Kučerová

The bonding of wood with assembly adhesives is crucial for manufacturing wood composites, such as solid wood panels, glulam, furniture parts, and sport and musical instruments. This work investigates 13 hardwoods—bangkirai, beech, black locust, bubinga, ipé, iroko, maçaranduba, meranti, oak, palisander, sapelli, wengé and zebrano—and analyzes the impact of their selected structural and physical characteristics (e.g., the density, cold water extract, pH value, roughness, and wettability) on the adhesion strength with the polyvinyl acetate (PVAc) adhesive Multibond SK8. The adhesion strength of the bonded hardwoods, determined by the standard EN 205, ranged in the dry state from 9.5 MPa to 17.2 MPa, from 0.6 MPa to 2.6 MPa in the wet state, and from 8.5 MPa to 19.2 MPa in the reconditioned state. The adhesion strength in the dry state of the bonded hardwoods was not influenced by their cold water extracts, pH values, or roughness parallel with the grain. On the contrary, the adhesion strength was significantly with positive tendency influenced by their higher densities, lower roughness parameters perpendicular to the grain, and lower water contact angles.


1998 ◽  
Vol 11 (1) ◽  
pp. 393-393
Author(s):  
Fangjun Lu ◽  
Mei Wu ◽  
Tipei Li ◽  
Xuejun Sun

In the paper we report the discovery of X-ray emission differences in SNR MSH14-63 based on the ROSAT PSPC observation. The structures of MSH14-63 are different in different energy bands. These images along with the radial brightness distributions in these energy bands show the existence of a region which only emit X-ray photons harder than l.OkeV. Though weak, there actually exist large scale X-ray emissions beyond the bright rim in many parts of the northeast remnant component, which is in conflict with the Sedov phase assumption used in previous research. These new soft X-ray features provide astronomers more information to study its physical characteristics.


Nanomaterials ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 587 ◽  
Author(s):  
Yan-Dong Guo ◽  
Jun-Feng Su ◽  
Ru Mu ◽  
Xin-Yu Wang ◽  
Xiao-Long Zhang ◽  
...  

Graphene has attracted attention in the material field of functional microcapsules because of its excellent characteristics. The content and state of graphene in shells are critical for the properties of microcapsules, which are greatly affected by the charge adsorption equilibrium. The aim of this work was to investigate the effect of pH value on the microstructure and properties of self-assembly graphene microcapsules in regard to chemical engineering. Microcapsule samples were prepared containing liquid paraffin by a self-assembly polymerization method with graphene/organic hybrid shells. The morphology, average size and shell thickness parameters were investigated for five microcapsule samples fabricated under pH values of 3, 4, 5, 6 and 7. The existence and state of graphene in dry microcapsule samples were analyzed by using methods of scanning electron microscope (SEM), transmission electron microscope (TEM) and X-ray photoelectron spectroscopy (XPS). Fourier Transform Infrared Spectoscopy (FT-IR) and Energy Dispersive Spectrometer (EDS) were applied to analyze the graphene content in shells. These results proved that graphene had existed in shells and the pH values greatly influenced the graphene deposition on shells. It was found that the microcapsule sample fabricated under pH = 5 experienced the largest graphene deposited on shells with the help of macromolecules entanglement and electrostatic adherence. This microcapsules sample had enhanced thermal stability and larger thermal conductivity because of additional graphene in shells. Nanoindentation tests showed this sample had the capability of deforming resistance under pressure coming from the composite structure of graphene/polymer structure. Moreover, more graphene decreased the penetrability of core material out of microcapsule shells.


2012 ◽  
Vol 454 ◽  
pp. 324-328
Author(s):  
Yan He ◽  
Ya Jing Liu ◽  
Yong Lin Cao ◽  
Li Xia Zhou

Infra-red absorption spectrometry, X-ray diffraction observations and characterization tests based on silicon molybdenum colorimetric method were used to investigate the optimal pH value controlling the stability of the silicic acid form. The experiment process was done by using sodium silicate as raw material. The results showed that the solution of silicate influenced the polymerization. The active silicic acid solution with a certain degree of polymerization was obtained by controlling the pH values.


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