scholarly journals RECYCLING TECHNOLOGY OF ACTIVE MATERIALS OF THE ZINC-MANGANESE CURRENT SOURCES

2021 ◽  
Vol 87 (4) ◽  
pp. 128-136
Author(s):  
Viktor Diamant ◽  
Andrey Simonov

It is being investigated whether it is possible to develop a low-cost method for processing used Zn-MnO2 primary chemical power sour­ces, which is focused on a closed cycle of ge­nerating zinc-manganese power sources from wasted batteries. It is proposed that chemical processing reagents be replaced with less dangerous ones for the environment and people, in accordance with «green chemi» principles. The existing hydrometallurgical method of processing of primary current sources with selective extraction of the spent part of the anode mass is modified and laboratory processed. The stage of additional extraction of arsenic is entered. The proposed technological scheme avoids heavy air loads in the form of carbon dioxide emissions by eliminating the stage of burning organic matter. The use of acetic acid allows to avoid sulfuric acid discharges and to obtain high-quality for secondary production of cathode mass of new chemical current sour­ces, as well as to obtain technical zinc powder and active zinc powder using hydrometallurgical technology for anode mass production of primary batteries. Also, the presence of stages of extraction of heavy metal ions (Hg2 +, Pb2 +, Cd2 +) and Arsenic to obtain products that can be further used in other technological processes makes this technology virtually waste-free, and in the stages of recovery of acetic acid and hypochlorite – closed. Thus, the use of the proposed technological schemes allows to make such production not only a little harmful to the environment, but also for workers, as well as to simplify the requirements for technological equipment.

Proceedings ◽  
2019 ◽  
Vol 14 (1) ◽  
pp. 39
Author(s):  
Zahira. El khalidi ◽  
Maryam Siadat ◽  
Elisabetta. Comini ◽  
Salah. Fadili ◽  
Philippe. Thevenin

Chemical gas sensors were studied long ago and nowadays, for the advantageous role they provide to the environment, health condition monitoring and protection. The recent studies focus on the semiconductors sensing abilities, especially of non toxic and low cost compounds. The present work describes the steps to elaborate and perform a chemical sensor using intrinsic and doped semiconductor zinc oxide. First, we synthesized pure oxide using zinc powder, then, two other samples were established where we introduced the same doping percentage of Al and Sn respectively. Using low cost spray pyrolysis, and respecting the same conditions of preparation. The obtained samples were then characterized by X Ray Diffraction (XRD) that revealed the hexagonal wurzite structure and higher crystallite density towards the direction (002), besides the appearance of the vibration modes related to zinc oxide, confirmed by Raman spectroscopy. SEM spectroscopy showed that the surface morphology is ideal for oxidizing/reduction reactions, due to the porous structure and the low grain sizes, especially observed for the sample Sn doped ZnO. The gas testing confirms these predictions showing that the highest response is related to Sn doped ZnO compared to ZnO and followed by Al doped ZnO. The films exhibited responses towards: CO, acetone, methanol, H2, ammonia and NO2. The concentrations were varied from 10 to 500 ppm and the working temperatures from 250 to 500°C, the optimal working temperatures were 350 and 400 °C. Sn doped ZnO showed a high response towards H2 gas target, with a sensitivity reaching 200 at 500 ppm, for 400 °C.


2014 ◽  
Vol 540 ◽  
pp. 267-271
Author(s):  
Xin Liu ◽  
Lin Yan Li ◽  
Fan Yun Zeng ◽  
Xue Jun Wang ◽  
Sheng Ming Xu

With the rapid development and wide application of Li-ion batteries, cathode materials containing value metals Co, Ni and Mn are blended by several kind of metal oxide presently for pursuing high safe stability and low cost. The composition of spent Li-ion batteries has become complicated and optimum leaching condition varied. In this paper, leaching process for the mixture of pure LiCoO2and Li (Ni1/3Co1/3Mn1/3)O2was studied. With an increase in component of LiCoO2in mixed materials, the optimum leaching condition varied as: temperature from 60°C to 90°C, H2O2addition amount from 0.54 to 0.75ml/g and liquid-solid ratio from 10 to 20. According to this result, a real mixed spent batteries materials was recovered by being leached in 2M H2SO4at temperature of 90°C, liquid-solid ratio 20 and 0.6ml/g H2O2added. The leaching efficiencies of Co, Ni, Mn, Li were 96.88%, 93.71%, 92.12%, 99.43% respectively. Cu, Al and Fe in solution were removed by precipitation and solvent extraction. Finally, Ni, Co, Mn were extracted by D2EHPA for separating with Na+and other impurities, which is used as a raw materials for preparation of cathode active materials in batteries.


2018 ◽  
Author(s):  
Mercy Nyamewaa Asiedu ◽  
Anish Simhal ◽  
Usamah Chaudhary ◽  
Jenna L. Mueller ◽  
Christopher T. Lam ◽  
...  

AbstractGoalIn this work, we propose methods for (1) automatic feature extraction and classification for acetic acid and Lugol’s iodine cervigrams and (2) methods for combining features/diagnosis of different contrasts in cervigrams for improved performance.MethodsWe developed algorithms to pre-process pathology-labeled cervigrams and to extract simple but powerful color and textural-based features. The features were used to train a support vector machine model to classify cervigrams based on corresponding pathology for visual inspection with acetic acid, visual inspection with Lugol’s iodine, and a combination of the two contrasts.ResultsThe proposed framework achieved a sensitivity, specificity, and accuracy of 81.3%, 78.6%, and 80.0%, respectively when used to distinguish cervical intraepithelial neoplasia (CIN+) relative to normal and benign tissues. This is superior to the average values achieved by three expert physicians on the same data set for discriminating normal/benign cases from CIN+ (77% sensitivity, 51% specificity, 63% accuracy).ConclusionThe results suggest that utilizing simple color- and textural-based features from visual inspection with acetic acid and visual inspection with Lugol’s iodine images may provide unbiased automation of cervigrams.SignificanceThis would enable automated, expert-level diagnosis of cervical pre-cancer at the point-of-care.


Author(s):  
Mohd Ahamad

A new concept in power generation is a microgrid. The Microgrid concept assumes a cluster of loads and microsources operating as a single controllable system that provides power to its local area. This concept provides a new paradigm for defining the operation of distributed generation. The microsources of special interest for MGs are small (<100-kW) units with power electronic interfaces. These sources are placed at customers sites. They are low cost, low voltage and have a high reliability with few emissions. Power electronics provide the control and flexibility required by the MG concept. A properly designed power electronics and controllers insure that the MG can meet the needs of its customers as well as the utilities. The goal of this project is to build a complete model of Microgrid including the power sources, their power electronics, and a load and mains model in THE HOMER. The HOMER Micropower Optimization Model is a computer model developed by the U.S. National Renewable Energy Laboratory (NREL) to assist in the design of micropower systems and to facilitate the comparison of power generation technologies across a wide range of applications. HOMER models a power system’s physical behavior and its life-cycle cost, which is the total cost of installing and operating the system over its life span. HOMER allows the modeler to compare many different design options based on their technical and economic merits. It also assists in understanding and quantifying the effects of uncertainty or changes in the inputs.


Author(s):  
Sen Yang ◽  
Ting Li ◽  
Yiwei Tan

Potassium-ion batteries (PIBs) that serve as low-cost and large-scale secondary batteries are regarded as promising alternatives and supplement to lithium-ion batteries. Hybrid active materials can be featured with the synergistic...


Polymers ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 765
Author(s):  
Jun-Bin Huang ◽  
Jagabandhu Patra ◽  
Ming-Hsien Lin ◽  
Ming-Der Ger ◽  
Yih-Ming Liu ◽  
...  

We demonstrate a facile and effective method, which is low-cost and easy to scale up, to fabricate holey graphene nanosheets (HGNSs) via ultrafast heating during synthesis. Various heating temperatures are used to modify the material properties of HGNSs. First, we use HGNSs as the electrode active materials for electric double-layer capacitors (EDLCs). A synthesis temperature of 900 °C seems to be optimal, i.e., the conductivity and adhesion of HGNSs reach a compromise. The gravimetric capacitance of this HGNS sample (namely HGNS-900) is 56 F·g−1. However, the volumetric capacitance is low, which hinders its practical application. Secondly, we incorporate activated carbon (AC) into HGNS-900 to make a composite EDLC material. The effect of the AC:HGNS-900 ratio on the capacitance, high-rate performance, and cycling stability are systematically investigated. With a proper amount of HGNS-900, both the electrode gravimetric and volumetric capacitances at high rate charging/discharging are clearly higher than those of plain AC electrodes. The AC/HGNS-900 composite is a promising electrode material for nonaqueous EDLC applications.


Water ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 2015
Author(s):  
I.A. Vasiliadou ◽  
J.A. Melero ◽  
R. Molina ◽  
D. Puyol ◽  
F. Martinez

One of the current challenges in the treatment of wastewater is the recovery and/or transformation of their resources into high value-added products, such as biohydrogen. The aim of the present study was to optimize the production of hydrogen by mixed cultures of purple phototrophic bacteria (PPB), targeting in low CO2 emission. Batch assays were conducted using different carbon (malic, butyric, acetic acid) and nitrogen (NH4Cl, Na-glutamate, N2 gas) sources by varying the chemical oxygen demand to nitrogen ratio (COD:N 100:3 to 100:44), under infrared radiation as sole energy source. Malate-glutamate (COD:N 100:5.5) and malate-NH4-N (COD:N 100:3) fed cultures, exhibited high H2 production rates of 2.3 and 2.5 mLH2/Lh, respectively. It was observed that the use of glutamate decreased the CO2 emission by 74% (13.4 mLCO2/L) as compared to NH4-N. The H2 production efficiency achieved by organic carbon substrates in combination with glutamate, was in the order of malic (370 mLH2/L) > butyric (145 mLH2/L) > acetic acid (95 mLH2/L). These substrates entailed partitioning of reducing power into biomass at 64%, 50% and 48%, respectively, whereas reductants were derived to biohydrogen at 5.8%, 6.1% and 2.1%, respectively. These results suggest that nitrogen source and carbon dioxide emissions play an important role in the optimization of hydrogen production by PPB.


Materials ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 842 ◽  
Author(s):  
Yanqing Fu ◽  
Qiliang Wei ◽  
Gaixia Zhang ◽  
Yu Zhong ◽  
Nima Moghimian ◽  
...  

In this work, we investigated three types of graphene (i.e., home-made G, G V4, and G V20) with different size and morphology, as additives to a lithium iron phosphate (LFP) cathode for the lithium-ion battery. Both the LFP and the two types of graphene (G V4 and G V20) were sourced from industrial, large-volume manufacturers, enabling cathode production at low cost. The use of wrinkled and/or large pieces of a graphene matrix shows promising electrochemical performance when used as an additive to the LFP, which indicates that the features of large and curved graphene pieces enable construction of a more effective conducting network to realize the full potential of the active materials. Specifically, compared to pristine LFP, the LFP/G, LFP/G V20, and LFP/G V4 show up to a 9.2%, 6.9%, and 4.6% increase, respectively, in a capacity at 1 C. Furthermore, the LFP combined with graphene exhibits a better rate performance than tested with two different charge/discharge modes. Moreover, from the economic and electrochemical performance view point, we also demonstrated that 1% of graphene content is optimized no matter the capacity calculated, based on the LFP/graphene composite or pure LFP.


KYAMC Journal ◽  
2018 ◽  
Vol 9 (2) ◽  
pp. 56-60
Author(s):  
Nahid Yusuf ◽  
Md Ahmed Ali ◽  
Nazmun Nahar ◽  
Shipra Chaudhury ◽  
Md Zillur Rahman

Background: Visual inspection of cervix after application of 3-5% acetic acid (VIA) is a potential alternative to Pap smear cytology for screening of cervical cancer in resource poor settings.Objectives: This study was to evaluate the performance of visual inspection based screening approach in the detection of precancerous and early cancerous lesions of the cervix.Materials & Methods: VIA was carried out in 540 eligible women attending Gynae OPD. Detection of well-defined, opaque, acetowhite lesion close to squamocolumnar junction or in transitional zone of the cervix constituted positive VIA. All screened women evaluated by colposcopy and biopsy were taken from colposcopically suspected areas. The final diagnosis was based on histology.Results: Out of 540 patients, 328 were VIA negative and 212 were VIA positive. Colposcopy showed normal results in 340 cases, low grade CIN in 138 cases, high grade CIN in 44 cases and cancer in 18 cases. There were biopsy proven chronic cervicitis and metaplastic changes in 423 cases, CIN I in 66 cases, CIN II in 25 cases, CIN III / carcinoma-in-situ in 5 cases. The sensitivity of VIA was 74.36%, specificity 70.45%, positive predictive value 41.04%, & negative predictive value 90.85%.Conclusion: VIA can differentiate a normal cervix from a precancerous cervix with reasonable accuracy. As it is low cost and simple method, it can be set in any hospital or any health care centre of rural or urban areas of poor resource settings.KYAMC Journal Vol. 9, No.-2, July 2018, Page 56-60


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