scholarly journals CHITIN- AND CHITOSAN BIOSORBENTS FROM CITRIC A CID MYCELIAL INDUSTRIAL WASTE

Food systems ◽  
2018 ◽  
Vol 1 (2) ◽  
pp. 55-62 ◽  
Author(s):  
L. V. Novinyuk ◽  
D. K. Kulyov ◽  
I. V. Negrutsa ◽  
P. Z. Velinzon
Keyword(s):  
Heavy Metals ◽  
Theoretical Model ◽  
Industrial Waste ◽  
Copper Ions ◽  
Sorption Isotherms ◽  
Test Results ◽  
Coordination Bonds ◽  
Chitin And Chitosan ◽  
By Products ◽  
Better Than

The goal of this study is to examine sorption capacity of chitin-glucan (ChGC) and chitosan-glucan (CsGC) biopolymer complexes extracted from the fungus Aspergillus niger mycelium. According to the findings chitosanglucan complex sorbs lead and copper ions (130–140 mg/g) better than chitin-glucan complex (50–80 ex mg/g). Langmuir theoretical model with R2= 0,996 determination coefficient well describe sorption isotherms. It is shown the chelate complex formation compound character based on ion and coordination bonds by chitin and chitosan biopolymers is more complex. According to test results the production of chitin and chitosan containing biopolymers from citric acid production mycelium by-products has a good future.  The above biopolymers have a functional use. Besides of that they sorbs heavy metals and radionuclide ions.

scholarly journals Experimental Study on Solidification of Pb2+ in Fly Ash-Based Geopolymers

2021 ◽  
Vol 13 (22) ◽  
pp. 12621
Author(s):  
Fang Liu ◽  
Ran Tang ◽  
Baomin Wang ◽  
Xiaosa Yuan
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Fly Ash ◽  
Heavy Metal Ions ◽  
Test Results ◽  
Good Resistance ◽  
Domestic Waste ◽  
Before And After ◽  
Better Than ◽  
Solidified Body

Fly ash from the incineration of domestic waste contains heavy metals, which is harmful to the environment. To reduce and prevent their contamination, heavy metal ions need to be sequestered. In this study, the geopolymer prepared by fly ash, a kind of power plant waste, is used to cure the heavy metal Pb2+, and to investigate the effect of different concentrations of Pb2+ on the compressive strength of the solidified body at different ages; the curing effect is judged by the toxic leaching concentration of heavy metals; the resistance of the solidified body to immersion is evaluated by comparing the change in strength before and after leaching; the fly ash-based geopolymer solidified body is compared with the cement solidified body in terms of curing effectiveness; the properties of the geopolymer and its mechanism of curing heavy metals are explored by microscopic tests. The results show that the fly ash-based geopolymer solidified body has good resistance to immersion; the optimum curing concentration of Pb2+ in fly ash-based geopolymers is 2.0%; compared to pure geopolymers, the strength of the solidified body at 28 d decreases by only 13.0%, and the leaching concentration of Pb2+ is 4.73 mg·L−1, which meets the specification requirements; the curing effect of the fly ash-based geopolymer is better than the cement solidified body; the microscopic test results indicate that the curing of Pb2+ by the fly ash-based geopolymer is a combination of both chemical bonding and physical fixation.

Implementasi Voip Server Berbasis IPV6 Dengan Raspberry PI

2019 ◽  
Vol 9 (01) ◽  
pp. 47-54
Author(s):  
Rabbai San Arif ◽  
Yuli Fitrisia ◽  
Agus Urip Ari Wibowo
Keyword(s):  
Internet Protocol ◽  
Wireless Transmission ◽  
Raspberry Pi ◽  
Test Results ◽  
Average Delay ◽  
Ipv6 Network ◽  
Ip Network ◽  
Selection Of ◽  
Better Than

Voice over Internet Protocol (VoIP) is a telecommunications technology that is able to pass the communication service in Internet Protocol networks so as to allow communicating between users in an IP network. However VoIP technology still has weakness in the Quality of Service (QoS). VOPI weaknesses is affected by the selection of the physical servers used. In this research, VoIP is configured on Linux operating system with Asterisk as VoIP application server and integrated on a Raspberry Pi by using wired and wireless network as the transmission medium. Because of depletion of IPv4 capacity that can be used on the network, it needs to be applied to VoIP system using the IPv6 network protocol with supports devices. The test results by using a wired transmission medium that has obtained are the average delay is 117.851 ms, jitter is 5.796 ms, packet loss is 0.38%, throughput is 962.861 kbps, 8.33% of CPU usage and 59.33% of memory usage. The analysis shows that the wired transmission media is better than the wireless transmission media and wireless-wired.

Kemampuan Komunikasi Matematika: Studi Komparasi Pembelajaran Number Head Together (NHT) dan Media Power Point (PPT)

2020 ◽  
Vol 3 (1) ◽  
pp. 39-50
Author(s):  
Bernadeta Ritawati ◽  
Sri Wahyuni
Keyword(s):  
Communication Skills ◽  
Hypothesis Test ◽  
Test Results ◽  
Mathematical Communication ◽  
Cluster Technique ◽  
Significance Level ◽  
Quasi Experimental ◽  
Power Point ◽  
Media Power ◽  
Better Than

This research is a quasi-experimental study that aims to determine the comparison of students' mathematical communication abilities with the cooperative learning model of the NHT and PPT media in class VII SMP Negeri 02 Ngabang. The population in this study were all students of class VII SMP 02 Ngabang consisting of 3 classes. The sample in this study was taken by using the Random Sampling Cluster technique. Class VII A as class I experimental class with 24 students and class VII B as a experimental class II with 24 students. The instruments used were pretest and posttest in the form of description. Data analysis uses the t test with a significance level of 5%. The results showed the average posttest for the NHT class was 72.5 and the average posttest for the PP class was 66.666. From the posttest hypothesis test results obtained t hitung> t tabel (1.9522> 1,667). Because t_hitung> t_tabel, H_0 is rejected and H_a is accepted. This means that students' mathematical communication skills taught with the NHT are better than using Power point media.

scholarly journals Evaluation of the Feasibility of NaCaPO4-Blended Zirconia as a New CAD/CAM Material for Dental Restoration

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3819
Author(s):  
Ting-Hsun Lan ◽  
Yu-Feng Chen ◽  
Yen-Yun Wang ◽  
Mitch M. C. Chou
Keyword(s):  
Computer Aided Design ◽  
Optical Microscope ◽  
Dental Restoration ◽  
Numerical Control ◽  
Test Results ◽  
Cnc Machine ◽  
Computer Aided ◽  
Cad Cam ◽  
Aided Design ◽  
Better Than

The computer-aided design/computer-aided manufacturing (CAD/CAM) fabrication technique has become one of the hottest topics in the dental field. This technology can be applied to fixed partial dentures, removable dentures, and implant prostheses. This study aimed to evaluate the feasibility of NaCaPO4-blended zirconia as a new CAD/CAM material. Eleven different proportional samples of zirconia and NaCaPO4 (xZyN) were prepared and characterized by X-ray diffractometry (XRD) and Vickers microhardness, and the milling property of these new samples was tested via a digital optical microscope. After calcination at 950 °C for 4 h, XRD results showed that the intensity of tetragonal ZrO2 gradually decreased with an increase in the content of NaCaPO4. Furthermore, with the increase in NaCaPO4 content, the sintering became more obvious, which improved the densification of the sintered body and reduced its porosity. Specimens went through milling by a computer numerical control (CNC) machine, and the marginal integrity revealed that being sintered at 1350 °C was better than being sintered at 950 °C. Moreover, 7Z3N showed better marginal fit than that of 6Z4N among thirty-six samples when sintered at 1350 °C (p < 0.05). The milling test results revealed that 7Z3N could be a new CAD/CAM material for dental restoration use in the future.

Influence of Collagen Status on Microstructures of Porous Collagen/TCP Composites

2007 ◽  
Vol 330-332 ◽  
pp. 495-498
Author(s):  
Chao Zou ◽  
Wen Jian Weng ◽  
Xu Liang Deng ◽  
Kui Cheng ◽  
Pi Yi Du ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Cell Growth ◽  
Tricalcium Phosphate ◽  
Freeze Drying ◽  
Alkali Treatment ◽  
Test Results ◽  
Collagen Matrices ◽  
The Difference ◽  
Porous Composites ◽  
Better Than

Two starting collagens, sponge and floc collagen, were used to prepare collagen/tricalcium phosphate (TCP) composites. The resulting composites were porous and had 200μm pore size. However, there was a difference in the microstructure of the pore walls for the composites derived from the two collagens, the pore walls in sponge collagen/TCP composite were still porous and had 200 nm micropores size, TCP particles were trapped in collagen matrices. While floc collagen/TCP composite had smooth and dense walls in which TCP particles were embedded. The difference could be attributed to the starting collagen with different status. Sponge collagen has a soft structure, which easily becomes disassembled fibrils during alkali treatment, the disassembled fibrils are integrated again to form a dense morphology for pore walls after freeze-drying. While floc collagen has already a low disassembly degree, the alkali treatment could not be able to separate the fibrils, this remains as micropores in pore walls after freeze-drying. Both porous composites are significant in bone tissue engineering or regeneration. MTT test results showed the two composites had good cytocompatibility, and sponge collagen/TCP composite was somewhat better than floc collagen/TCP composite, which could result from that micropores derived roughness in pore walls of sponge collagen/TCP composite is suitable for cell growth.

scholarly journals Development of UHPC Mixtures Utilizing Natural and Industrial Waste Materials as Partial Replacements of Silica Fume and Sand

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Shamsad Ahmad ◽  
Ibrahim Hakeem ◽  
Mohammed Maslehuddin
Keyword(s):  
Silica Fume ◽  
Industrial Waste ◽  
Steel Slag ◽  
Limestone Powder ◽  
Waste Materials ◽  
Cement Kiln ◽  
Test Results ◽  
Strength Criteria ◽  
Natural Pozzolana ◽  
Kiln Dust

In the exploratory study presented in this paper, an attempt was made to develop different mixtures of ultrahigh performance concrete (UHPC) using various locally available natural and industrial waste materials as partial replacements of silica fume and sand. Materials such as natural pozzolana (NP), fly ash (FA), limestone powder (LSP), cement kiln dust (CKD), and pulverized steel slag (PSS), all of which are abundantly available in Saudi Arabia at little or no cost, were employed in the development of the UHPC mixtures. A base mixture of UHPC without replacement of silica fume or sand was selected and a total of 24 trial mixtures of UHPC were prepared using different percentages of NP, FA, LSP, CKD, and PSS, partially replacing the silica fume and sand. Flow and 28-d compressive strength of each UHPC mixture were determined to finally select those mixtures, which satisfied the minimum flow and strength criteria of UHPC. The test results showed that the utilization of NP, FA, LSP, CKD, and PSS in production of UHPC is possible with acceptable flow and strength. A total of 10 UHPC mixtures were identified with flow and strength equal to or more than the minimum required.

Arsenic removal from groundwater through iron oxyhydroxide coated waste productsA paper submitted to the Journal of Environmental Engineering and Science.

2009 ◽  
Vol 36 (5) ◽  
pp. 881-888 ◽  
Author(s):  
Elsadig A.M. Abdallah ◽  
Graham A. Gagnon
Keyword(s):  
Ferric Oxide ◽  
Arsenic Removal ◽  
Ferric Hydroxide ◽  
Structure Surface ◽  
Seafood Industry ◽  
Isotherm Adsorption ◽  
Scallop Shells ◽  
Glass Recycling ◽  
By Products ◽  
Better Than

The goal of this research was to remove arsenic from groundwater supplies via adsorption into media obtained from waste material generated as by-products from glass recycling programs and the seafood industry such as crushed glass and scallop shells. During the course of this research four new adsorbents were developed: ferric hydroxide coated crushed glass (FHCCG); ferric oxide coated crushed glass (FOCCG); ferric hydroxide coated scallop shells (FHCSS); and ferric oxide coated scallop shells (FOCSS). The adsorbents were characterized through evaluation of their structure, surface area, chemical composition, iron content, and coating stability. Efficiency of the adsorbents to remove arsenic from water was examined through batch kinetic and isotherm adsorption experiments. The adsorption capacity of the adsorbents was also evaluated by performing column experiments using real ground waters and a synthetic water. Arsenic removal to a concentration less than 10 μg/L was achieved with the FHCSS and more than 9000 bed volumes of water were treated before the breakthrough point was reached. The research results revealed that scallop shells coated with ferric hydroxideperformed better than crushed glass coated with ferric hydroxide. Both FOCCG and FOCSS had poor arsenic removal compared with FHCSS and granular ferric hydroxide (GFH). Ferric hydroxide coated scallop shells performed similarly to GFH.

scholarly journals Synthesis of 2-Substitued Indoles via Pd-Catalysed Cyclization in an Aqueous Micellar Medium

Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 3917
Author(s):  
Sofia Siciliano ◽  
Elena Cini ◽  
Maurizio Taddei ◽  
Giorgia Vinciarelli
Keyword(s):  
Water Environment ◽  
Delivery Mode ◽  
Micellar Medium ◽  
Dielectric Heating ◽  
Microwave Dielectric ◽  
Microwave Dielectric Heating ◽  
Heating Mode ◽  
Aqueous Micellar Medium ◽  
By Products ◽  
Better Than

The synthesis of 2-substituted indoles starting from the corresponding unprotected 2-alkynylanilines was made possible in 3% TPGS-750-M water using Pd(OAc)2 alone as the catalyst. The reaction was sensitive to the heating mode respect to the nature of the starting material as, in many cases, convectional heating was better than microwave dielectric heating. The MW (microwave) delivery mode had also an influence in the formation of by-products and, consequently, product yields. A tandem Sonogashira-cyclisation reaction was also accomplished using Pd(OAc)2/Xphos in the nanomicellar water environment.

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