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Энэхүү судалгааны ажлаар байгалийн цеолит болон гулуронатын полимер ашиглан усан орчноос хүнд металыг шингээх чадвартай композит материал гарган авах тохиромжтой нөхцөлийг тогтоолоо. Цеолит нь сүвэрхэг бүтэцтэй, хөнгөнцагаант суурь болон катион, усны молекулуудыг агуулсан эрдэс бөгөөд шингээгч материалд өргөн хэрэглэгддэг нэгдэл юм. Тасралттай шингээлтийн процессын үед нунтаг цеолит нь шингээлтийг сайтар явуулах боловч, тасралтгүй баганан шингээлтийн үед нунтаг материал нь усыг нэвтрүүлэх чадваргүй байдаг. Иймээс мөхлөг хэлбэрийн (packed bed) баганан шингээлтэнд тохирох жижиг үрэл хэлбэрийн композит материалыг гарган авах, улмаар усан орчинд хичнээн удсан ч буцаж тэлэхгүй байх материалыг гарган авах нь бидний судалгааны ажлын гол зорилго болсон билээ. Тасралтгүй урсгалтай аргаар явагдах баганан процессын үед композит материалаар тэлэлтгүй ус нэвтрүүлэх хурд нь тогтмол байх нь шингээлтийн баганын чухал үзүүлэлт болно. Иймээс мөхлөг хэлбэрийн үрлэн шингээгч материалыг гарган авахдаа усан орчинд тэлэлт өгөхгүй байх тохиромжтой нөхцлийг тогтоон, амжилттай гарган авлаа. Цеолит агуулсан композит материалыг гарган авахад Na-альгинатын полимерын концентрацийг 1-2\% байхад тохиромжтой болох нь харагдлаа. Түүнчлэн $CaCl_2$-ын уусмалтай харьцуулахад $BaCl_2$-ийн уусмалаар бэлтгэсэн композит үрэл нь тэлэлтийн харьцаа багатай байгаа нь уусмал дотор хангалттай хэмжээний $Ba$ атом байхад тогтвортой композит үрэл үүсэж болохыг харуулж байна. $BaCl_2$ - ийн 10% - ийн үед гарган авсан материал нь тэлэлтийн харьцаа 1 орчим байлаа.
In this study the result of theoretical calculation and experiments, terminal groups with high efficiency of Organic Photovoltaics (OPVs) were chosen based on a linear correlation between the efficiency of OPVs and dipole moments of terminal groups of the Self Assembled Monolayers (SAM) molecules by modifying the anode electrode surface chemically. The obtained results are the evidence of formation of self-assembled monolayer, which is fundamental method of nanotechnology. The result gives us the opportunity of preliminary calculation of the main performance of the OPVs considering the dipole moments of the terminal groups of surface-active molecule. By inserting SubPc which has high HOMO level as an electron donor, the Voc was reached from 0.54 V to 0.71 V due to formation of non-Ohmic contact with increasing the difference of HOMO of donor and LUMO of acceptor from 0.55 eV to 1.1 eV. As these results, electron donor material which has high value of HOMO should be used when the Ohmic contact was formed in OPVs was proved.
Because the combustion of automobile fuel has a negative impact on the environment, many countries such as China, Japan, South Korea, and Germany produce dimethyl ether and use it as fuel and gasoline. In this research work, the dehydration reaction to extract dimethyl ether from methanol was modeled on DWSIM program and the three main parameters of the reactor (conversion, selectivity, reactor yield) were calculated. Three basic parameters of the reactor were varied in the calculations and the simulated results were compared with the experimental values. A kinetic model has been established for the dehydration of methanol to dimethyl ether over γ-Al2O3 acid function, the most widely used catalyst. The kinetic parameters are based on solving the mass conservation equation for each component, on the assumption of plug flow and isothermal operation. The methanol conversion was increased with increasing the feed temperature, in contrast lover methanol conversion was calculated with higher pressure. Increase of the reaction yield were observed in the condition where higher molar fraction of water in the feed. The dimethyl ether can be separated with 96% purity by means of gas-liquid separator and distillation column after the reaction. The comparing the degree of methanol conversion with the experimental value performed under the same conditions, it was in good agreement with the experimental value at a temperature lower than 361°C.
ABSTRACT The determination of the chemical composition of particulate matter is important to predict the sources, formation, and effects of pollutants in the atmosphere. In 2019, the Mongolian government banned the use of raw coal in Ulaanbaatar and promoted the use of an improved briquette fuel. As a result, atmospheric PM was reduced by approximately 50%, and ambient air quality was improved. On the other hand, the atmospheric sulfur dioxide concentration was increased more than two times. However, the chemical composition of the particulate matter (PM) has still not been evaluated since 2019, when they started the use of briquette fuel. This study focuses on the seasonal variations of the chemical composition of PM2.5 using ninety-five daily PM2.5 samples that were collected in Ulaanbaatar between 2017 and 2021. Ion chromatography and a carbon analyzer were used to examine the major nine inorganic ions and organic/elemental carbon. In warm seasons, magnesium, sodium, calcium, and potassium ions are higher than they are in cold seasons and are possibly dominated by natural origins, while sulfate was dominant during the cold season. The carbonaceous composition, sulfate, nitrate, and ammonium accounted for the majority of fine particles in winter. Except for summer, sulfate ions predominated, possibly due to fuel combustion. Chloride ion concentrations were increased in the last two winters, 2020 and 2021, when compared to 2017.
The determination of the chemical composition of particulate matter is important to predict the sources,formation, and effects of pollutants in the atmosphere. In 2019, the Mongolian government banned the use ofraw coal in Ulaanbaatar and promoted the use of an improved briquette fuel. As a result, atmospheric PM wasreduced by approximately 50%, and ambient air quality was improved. On the other hand, the atmospheric sulfurdioxide concentration was increased more than two times. However, the chemical composition of the particulatematter (PM) has still not been evaluated since 2019, when they started the use of briquette fuel. This studyfocuses on the seasonal variations of the chemical composition of PM2.5 using ninety-five daily PM2.5 samplesthat were collected in Ulaanbaatar between 2017 and 2021. Ion chromatography and a carbon analyzer were usedto examine the major nine inorganic ions and organic/elemental carbon. In warm seasons, magnesium, sodium,calcium, and potassium ions are higher than they are in cold seasons and are possibly dominated by naturalorigins, while sulfate was dominant during the cold season. The carbonaceous composition, sulfate, nitrate, andammonium accounted for the majority of fine particles in winter. Except for summer, sulfate ions predominated,possibly due to fuel combustion.
This study assesses the seasonal variations, potential sources, and health risks of fine particulate matter, PM2.5. Samples (n = 83) were collected at two urban sites of Ulaanbaatar. Inorganic ions, organic/elemental carbon, and metals were analyzed. Results exhibited a distinctive seasonality for all chemical compositions with sulfate being the dominant species of PM2.5 in winter. Comparably high concentrations of sulfate, nitrate, and ammonium were measured in winter, while concentrations of calcium and magnesium were higher in spring and summer rather than in other seasons. The results revealed that dominant sources of atmospheric PM2.5 are mainly due to emissions of coal combustion in the heating period, and soil dust resuspension is in the non-heating period.
In this study, increasing the work function of ITO (Indium Tin Oxide) electrode while reducing that of Al cathode was examined to successfully improve the Voc (Open Circuit Voltage) values of the of Organic PV (Photovoltaic) cells. For MIM (Metal Insulator Metal) type organic PV cells, the Vbi (Built in Potential) results from the Δφ (Work Function Difference) between the anode and cathode electrodes. Using high work function values for the ITOs used as an anode, an improvement in Vbi resulting from Δφ would be expected with organic PV cells. In the cells with Al cathode (named as bilayer cell), a slight increase in PCE from 0.13 % in the case as-cleaned ITO to 0.46 % in the case ITO modified with NO2– terminal group was observed. The FF value for the devices with variously configured ultra-thin layer such as BCP/Al, BCP/C6H5COOLi/Al, Alq3/Al, and Alq3/C6H5COOLi/Al is still larger (1.3 times increased) than those of the other devices with Al and C6H5COOLi/Al cathode electrodes. Introduction
The device performance of organic photovoltaics (OPVs) deposited on ITO electrodes were reported. For a typical device configuration of ITO/ZnPc/C60/Al with and without BCP as an exciton blocking layer, the device performances, including Jsc, Voc, FF, and p have been examined. In addition, the correlation between the change in the work function by the chemical modification of ITO and the device performances, including Jsc, Voc, FF, and ηp is examined and the PV characteristics before and after the chemical modification of ITO electrodes were compared.
Organic thin film photovoltaic (PV) cells have attracted attention because of their ease of fabrication and potential for low cost production. In this paper, we study the effects of chemical modification of indium-tin-oxide (ITO) on the performance of organic PV cells. The organic PV cells are fabricated, with the cell configuration of ITO/sub phthalocyanine (SubPc) (20 nm)/fullerene (C60) (40 nm)/Al with and without bathocuproine (BCP) (10 nm) between C60 and Al. By the use of para-substituted benzenesulfonyl chlorides with different terminal groups of H- and Cl-, the energy offset at the ITO/SubPc interface is tuned widely depending upon the interface dipoles and thus the correlation between the change in the ITO work function and the performance of the PV cells by chemical modification is examined.
Keywords. Organic Solar Cells, Efficiency, BCP, CuPc, Open Circuit Voltage, HOMO, LUMO Abstract. The performance and understanding of organic solar cells has progressed considerably over the last few years. An organic photovoltaic cell is fabricated, with the device configuration of indium-tin-oxide (ITO)/copper phthalocyanine (CuPc)/buckminsterfullerene (C60)/Al. The cell performance under illumination is examined with different organic layer and electrode structures. A cell incorporating 10-nm-thick organic layer of bathocuproine (BCP) as an exciton blocking layer shows a short circuit photocurrent density (Jsc) of ~3.5 mA/cm2, an open circuit photovoltage (Voc) of ~0.45 V, and a fill factor (FF) of ~0.5 with white Xe light illumination with an intensity of 100 mW cm-2.
Abstract. The performance and understanding of organic solar cells has progressed considerably over the last few years. An organic photovoltaic cell is fabricated, with the device configuration of indium-tin-oxide (ITO)/copper phthalocyanine (CuPc)/buckminsterfullerene (C60)/Al. C60 acts as an electron acceptor organic material while CuPc corresponds to a donor. The cell performance under illumination is examined with different organic layer and electrode structures. A cell incorporating 10-nm-thick organic layer of bathocuproine (BCP) as an exciton blocking layer shows a short circuit photocurrent density (Jsc) of ~3.5 mA/cm2, an open circuit photovoltage (Voc) of ~0.45 V, and a fill factor (FF) of ~0.5 with white Xe light illumination with an intensity of 100 mW cm-2.
