Дэлгэрэнгүй мэдээлэл

Аж үйлдвэрлэлийн хурдацтай хөгжил, уул уурхай, үйлдвэрлэл, техник технологиуд тасралтгүй хөгжихийн хэрээр тэдгээрийн хэрэглээ, хэрэгцээ, шаардлагууд улам нэмэгдэж байдаг. Үүний үр дүнд бидний хүрээлэн буй орчин болох агаар, ус, хөрсөнд хорт бодисууд хуримтлагдаж улмаар байгаль орчин, хүн, мал амьтны эрүүл мэндэд ноцтой сөрөг нөлөө үзүүлж байгаа нь манай орны хувьд тулгамдаж буй асуудлууд юм. Тиймээс энэхүү судалгааны ажлаар байгалийн нөөцийг эдийн засгийн эргэлтэд оруулах, байгалийн гаралтай хүний эрүүл мэндэд хоргүй шингээгч материалын сонголтод цеолит нь ион солилцооны өндөр идэвх, сүвэрхэг шинж чанараар төгс тохирсон эрдэс бөгөөд энэ шинж чанар дээр үндэслэн хямд, үр ашиг өндөртэй шингээгч композит материал гарган авч, тасралтгүй урсгалтай баганан шингээлт явуулах замаар хар тугалгаар бохирдсон усан уусмалаас хар тугалгыг бууруулах туршилтыг гүйцэтгэлээ. Байгалийн цеолитыг натрийн алгинат полимер материалтай хольж бөмбөлөг хэлбэрийн шингээгч материал гарган авсан. Гарган авсан композит материалаар баганан шингээлтийг явуулан шингээлтэд нөлөөлөх баганын голлох параметрүүд болох баганын эзлэхүүн, шингээгч материалын хэмжээ, бохирдсон уусмалын анхны концентраци, уусмалын эзлэхүүн зарцуулалтыг нөлөөг судаллаа. Цеолитын найрлага болон хар тугалганы концентрацийн өөрчлөлтийг багажийн шинжилгээ (XRD, XRF, AAC)  хийсэн. Баганын эзлэхүүнийг 2.5 см3 - 5 см3 болгож ихэсгэх үед  шингээлтийн эхний цэг дэх анхны уусмалын концентраци болон шингээлтийн дараах концентрацийн (C/C0)  харьцаа 3 дахин ихэссэж хар тугалганы бохирдлыг 60%, 88%-иар тус тус бууруулсан.  Баганын эзлэхүүн тогтмол 5.0 см3 байх үед эзлэхүүн зарцуулалтыг 2.5 мл/мин - 6.25 мл/мин болгон хувьсгахад шингээлт 4 дахин багассаж хар тугалганы бохирдлыг 96%, 42%-иар тус тус бууруулсан байна. Баганан шингээлтийн үеийн нийт уусмалын эзлэхүүн 200 мл, эзлэхүүн зарцуулалт 6.25  мл/мин байх үед уусмалын анхны концентрацийг хувьсган туршилтыг явуулахад эхний цэгийн C/C0   харьцаа  уусмалын концентраци ихсэх тусам дагаад ихсэж байсан. Төгсгөлийн цэгт өөрчлөлт ажиглагдаагүй. Баганын эзлэхүүн болон уусмалын анхны концентрацийг ихэсгэхэд гаргаж авсан композит материалын шингээлт  нэмэгдсэн бол эзлэхүүн зарцуулалтыг нэмэгдүүлэхэд шингээлт буурч байна. Улмаар гарган авсан композит материал нь хар тугалганы уусмалын концентрациас хамааран 40-60% бууруулж байгаа нь ижил төстэй материалуудаас багтаамж өндөртэй хар тугалганы бохирдолыг бууруулахад үр нөлөөтэй байгааг тодорхойлсон.

Энэхүү судалгааны ажлаар байгалийн нөөцийг эдийн засгийн эргэлтэд оруулах, байгалийн гаралтай хүний эрүүл мэндэд хоргүй шингээгч материалын сонголтод цеолит нь ион солилцооны өндөр идэвх, сүвэрхэг шинж чанараар төгс тохирсон эрдэс бөгөөд энэ шинж чанар дээр үндэслэн хямд, үр ашиг өндөртэй шингээгч композит материал гарган авч, тасралтгүй урсгалтай баганан шингээлт явуулах замаар хар тугалгаар бохирдсон усан уусмалын бохирдлыг бууруулах туршилтыг гүйцэтгэлээ. Байгалийн цеолитод механик боловсруулалтыг гариган бөмбөлөгт тээрмийг ашиглан гүйцэтгэж, натрийн алгинат полимер материалтай бөмбөлөг хэлбэрийн шингээгч материал гарган авсан. Гарган авсан композит материалаар баганан шингээлтийг явуулан шингээлтэд нөлөөлөх баганын голлох параметрүүд болох баганын эзлэхүүн, шингээгч материалын хэмжээ, бохирдсон уусмалын анхны концентраци, уусмалын эзлэхүүн зарцуулалтыг нөлөөг судаллаа. Цеолитын найрлага болон хар тугалганы концентрацийн өөрчлөлтийг багажийн шинжилгээ (XRD, XRF, AAC)  хийсэн. Баганын эзлэхүүнийг 2.5 см3 -5 см3 болгож ихэсгэх үед  шингээлтийн эхний цэг дэх анхны уусмалын концентраци болон шингээлтийн дараах концентрацийн (C/C0)  харьцаа 3 дахин ихэссэн.  Баганын эзлэхүүн тогтмол 5.0 см3 байх үед эзлэхүүн зарцуулалтыг 2.5 мл/мин - 6.25 мл/мин болгон хувьсгахад шингээлт 4 дахин багассан байна. Баганан шингээлтийн үеийн нийт уусмалын эзлэхүүн 200 мл, эзлэхүүн зарцуулалт 6.25  мл/мин байх үед уусмалын анхны концентрацийг хувьсган туршилтыг явуулахад эхний цэгийн C/C0   харьцаа  уусмалын концентраци ихсэх тусам дагаад ихсэж байсан. Төгсгөлийн цэгт өөрчлөлт ажиглагдаагүй. Баганын эзлэхүүн болон уусмалын анхны концентрацийг ихэсгэхэд гаргаж авсан композит материалын шингээлт  нэмэгдсэн бол эзлэхүүн зарцуулалтыг нэмэгдүүлэхэд шингээлт буурч байна. Улмаар гарган авсан композит материалын шингээлтийн багтаамжийг тооцоход уусмалын концентрациас хамааран 40-60 мг/гр гэж гарсан нь ижил төстэй материалуудаас багтаамж өндөртэй байгааг тодорхойлсон.

This work is aimed to study of distribution of chemical elements in soil, plans at area of radioactive ore deposit. For the first time, the distribution of chemical elements comprehensively studied through the area of the Kharaat , which is located in Dundgobi province (Mongolia). A total of 120 soil and plants samples were collected and 44 minor, trace elements and oxides were quantified.

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 work, some properties of the InAs/InGaAs quantum well (QW) were calculated, such as the wave functions and the charge density of the 2D free electron gas (2DEG) by solving the Poisson- Schroedinger equation. The thinner capping layer gives charge densities forming inside the QW that are higher than the thicker values. The optimal thickness of the capping layer can be 10 nm due to the most stable charge density and fully symmetrical wave functions. Our result indicates that higher charge densities can be found with higher Si-delta doping concentrations. However, the distance of the Si-delta doping also affects the charge population. The charge density linearly decreases with a higher Si-delta doping spacer; the thickness was chosen as 7nm. We performed the growth with different concentrations of Si with optimal thicknesses and compared them with the calculated values. There is good agreement between the simulations and experiments with the lower Si-doping concentrations.

Lead contamination was removal from aqueous solution by continuous flow column adsorption with composite material of Na-alginate and natural zeolite. The optimum conditions for the breakthrough curve were found depending on the parameters of the column such as the dimensions of the column, the amount of adsorbent material, the initial concentration of the contaminated solution, and the volume consumption of the solution. The adsorption breakthrough curve was obtained in the experimental condition, where the ratio of initial concentration of the aquas solution and the column volume was 3:8 and the total volume of the solution and the column volume ratio (VF/VR) was in the range of 1000 – 1300. According to the results of the breakthrough curve observed under the above optimal conditions, the adsorption capacity was 70.5 mg/g, which is higher than other similar studies conducted with high concentration solutions.

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.

InGaAs/InAs materials have surprising properties topological, spin-orbit coupling (SOC), and results in superconducting quantum bits around transistors of quantum computing. The growth of a quantum well (QW) structure with a semiconductor 7nm thick InAs sandwiched between InGaAs developed in high-mobility molecular beam epitaxy (HM-MBE). Some properties of the QW were simulated, such as the band structure, the wave functions, and the charge density of 2D free electron gas (2DEG) forming inside the QW by solving the Poisson-Schrodinger equation. Our work aimed to optimize the thicknesses of InGaAs layers and Si-delta doping concentration by avoiding many materials growth. The thicknesses of a capping layer (above the QW) a spacer layer of Si- delta doping (below the QW) differed from 2nm to 15 nm. From the calculations, we found the optimal thickness of the capping layer can be 10nm due to the most stable change density. The charge density linearly decreases with a higher Si-delta doping spacer, the thickness was chosen 7nm. Finally, we performed the growth with different Si-doping concentration with the optimal thicknesses and compared with simulated values. There is good agreement between the simulations and the experiments with the lower Si-doping concentrations. However, more charge density was measured than the simulated values, we assume that the charge of silicon atoms contributes itself to the 2DEG inside the QW.

In this study, the adsorption of hazardous atoms including lead on the silica surface (SiO2 [001]) was investigated using the first-principles method within the framework of density functional theory (DFT). We performed the full structural optimization and found the most stable configuration. Four different sites were considered for the surface of silica, as well as four different sites for the surface of silica with an Al atom, and the adsorption energy along with the equilibrium geometry was determined. When the absorption energy was calculated at the four positions, the surface of silica and the surface of silica with Al had the same higher absorption at the first site (-6.66 eV and -9.11 eV). The value of the absorption energy indicates that a strong chemical bond has been formed between the lead and the surface. The maximum values for the absorption energy of the lead atoms were -6.93 eV for the silica surface and -9.11 eV for the silica surface with the Al atom. Furthermore, the structure added by aluminum with the ratio of 1:5 to build a similar structure of a zeolite crystal. Which provided more absorption energy. The value of the absorption energy indicates that a strong chemical bond has been formed between the lead and the surface. The density of state (DOS) is shown that the bandgap was 2.78 eV for the silica surface and 2.65 eV for the silica surface with Al atoms. The addition of the lead atom reduced the width of the bandgap due to the creation of a trapping layer within the bandgap.

Монгол орны Дорноговь аймгийн Хараатын ураны орд газрын ургамал, ус, хөрсний зарим элемент нэгдлийн агуулгыг тодорхойлж, гарсан үр дүнд статистик анализын боловсруулалт хийснээр элемент хоорондын хамаарлыг хөрс, ус, ургамлын орчинд харахаас гадна дээж хоорондын хамаарлыг статистик боловсруулалтын Принсипал компонентын ПКА (Principle Component Analysis-PCA) аргыг ашиглан тогтоолоо.

Natural zeolite beads were prepared by encapsulating mesoporous zeolite into alginate beads via egg box method and its adsorption properties of Pb(II) ions were investigated in aqueous solution. Crystallinity and size reduction of natural zeolite were enhanced by mechanic modification of the ball milling process. FTIR and SEM-EDS analyses confirmed that mechanically modified zeolite particles were incorporated into alginate hydrogel. The highest adsorption amount of zeolite alginate beads was 87.47 mg/g after 20 h adsorption process. SEM-EDS result confirmed that the adsorption process has occurred on the surface of zeolite alginate beads. Adsorption kinetic data were fitted with Langmuir adsorption isotherm which showed that Pb2+ cation adsorbed into monolayers of adsorbent material. Moreover, we observed that calcium ion released after the Pb2+ adsorption process in the feed solution. Therefore, the adsorption mechanism of zeolite alginate beads explained by complex mechanisms including surface sorption and ion exchange of Pb2+ and Ca2+ in beads.

Mongolian natural zeolite has ability to adsorb heavy metal from water and it has been studied before. In those studies zeolite was mostly used in powder state. The aim of this study is to synthesize cryogel composite containing natural zeolite for adsorbent material of cation and anions. Embedding powder zeolite into cryogel reduces the agglomeration of powder sample, which makes it more convenient to use in adsorption process. Zeolite-cryogel composite was synthesized by cryoconcentration methods1-2 with 2 different reagent ratio. In the composite from the first method, zeolite was uniformly dispersed but it was not porous, while the composite from the second method was porous, zeolite particles were dispersed evenly through the cryogel column. Also, it was stable in the flow of the water. FT-IR analysis showed that the polymerization of cryogel and it matched with previous studies.3 SEM-EDX analysis showed that composite has macroporous structure and zeolite particles were embedded in the wall of cryogel. We used zeolite-cryogel composite for adsorption of arsenic in reactor and it adsorbed 1.669 mg/g in acidic solution. Powder zeolite is embedded into cryogel composite successfully and it adsorbed anionic arsenic from water. In further study, adsorption mechanism and optimal conditions of zeolite-cryogel on cation and anion will be investigated.

Zeolite alginate beads were developed by immobilizing mechanically modified and natural nanoporous zeolite into sodium alginate. Natural zeolite sample is determined as Clinoptilolite type of zeolite with BET average pore size of 8.3 nm. The developed beads used for adsorption of Pb(II) from aqueous solution. Alginate bead containing natural raw zeolite and mechanically modified natural zeolites were compared in terms of Pb(II) adsorption capacity. Prior to adsorption, natural zeolite was milled by planetary ball mill with 200 rpm speed and 3 mm zircon balls in range of 0-15 minutes. Adsorption experiment was conducted in batch reactor with 100-500 ppm initial concentration of Pb(II). Experiment result showed that modified zeolite was given higher adsorption amount than natural raw zeolite. After modification process, increase of peak intensity was observed in XRD analysis. This result may explain that ball-milling process increased purity of zeolite by removing natural impurity of sample. It tends to increase adsorption amount of Pb(II). Adsorption efficiency of zeolite alginate beads was all above 50% in pH range of 2 to 6 and highest removal efficiency was 94% at pH=3. The highest adsorption amount of Pb(II) was 87.37 mg/g with initial concentration of 500 ppm. Natural zeolite sample modified by ball milling process with 10 minutes in 200 rpm speed was given highest adsorption amount. This result showed that alginate beads with modified natural zeolite can be effective adsorbent for Pb(II) in various pH range.

This work is aimed to study the distribution of elements in soil, plants of one of the uranium deposits of Mongolia. There are many uranium Deposits with proven total reserves is 170,000tons. The Kharaat uranium deposit which is located in Dundgobiaimag was chosen as an object for studying. The Deposit is located in Southern of 330 km from Ulaanbaatar. Its proven reserve is 7288 t with U concentration 0.026%.

Mongolian natural zeolite from Tsagaan tsav had shown the ability of ion adsorption such as As or Pb from aqueous solution. In previous works, the zeolite mineral was used as powder in the batch process. However, it is not possible to use powder material for flow processes. Therefore, in this study, Arsenic adsorption ability of polymer embedded modified zeolite was investigated in two types of adsorption reactor. Modification of natural zeolite with magnesium oxide was carried out prior to polymer synthesis. SEM-EDX analysis result showed that the modification was successful. Zeolite polymer was synthesized by two different methods. Product of second method was high porous and zeolite particles were immobilized throughout the polymer. Adsorption in continuous column reactor was more effective than batch reactor. The adsorption amount was increased with time.

Бид энэхүү ажлаар InGaAs/InAlAs quantum well QW-д дельта хэлбэрийн цахиурын атомын хольц хийсэн ба QW ба цахиурын атомын хольцын үе хоорондын зайг 5 – 45 нм хүртэл өөрчлөн цахиурын атомын хольцыг QW-н дээр, доор байрлуулан тооцоо хийж, хольцын концентрацийг өөрчлөн QW дахь цэнэгийн концентрацид хэрхэн нөлөөлөхийг судлах зорилготой байлаа. Үүнээс цахиурын атомын хольцыг QW-с холдуулах тусам электроны концентраци буурч байсан ба QW-н дээр хольцыг байрлуулахад шугаман хамааралтай байсан. Хольцын концентраци ихсэхэд QW дотор үүсэх цэнэгийн хэмжээ ихсэж байна

Due to the high atomic number, low band gap and high electron mobility of III-IV semiconductors, the use of metamorphic InGaAs/InAlAs quantumwell-based deviceswas proposed for fast pixelated photon detectors. In thiswork, we are presenting a double side-segmented quantum well (QW) device, discussing its spatial resolution and analysing the crosstalk between pixels. The fabricated devices were tested with needle-shaped beams of synchrotron radiation with different energies and spot sizes. The position of the synchrotron radiation was estimated with a 1.3-m precision. The charge spread in the material and related crosstalk function between pixels were extracted from the position estimation measurements of the photon beams. The results show that the cross-talk between pixels is actually responsible for the different resolutions obtained, regardless of the experimental conditions, pointing out the importance of the geometry of the fabricated devices. Furthermore, it has been observed that the QW pixelation is mandatory for hybrid detector technology.

The InGaAs/InAlAs quantum well (QW) heterostructures, including single quantum well, super- lattices have special advantages for applications in high speed electronic and photonic devices. Their direct, low energy band gap and high electron mobility renders it capable of detecting photons rang- ing from visible to X-ray at room temperature. In this work, we simulated properties of quantum states inside the quantum well with different width thickness (5-45 nm). The simulation shows, a number of states changes from 1 to 6 while the well width increasing. The electron concentration was increasing until 25 nm then started slowly stabilizing.

Geological research and mining play important role for Mongolian economy. In order to explore new mining sources or estimate probable reserves, laboratory’s examination is very important. The laboratory analysis and investigations are important part of geological exploration and geological exploration depends on analysis technical capability, analysis quality and productivity of analytical works. The geology in its investigation is widely use various analytical techniques such as instrumental or radiochemical neutron activation analysis, X-ray fluorescence analysis-XRF, inductively coupled optic emission and inductively coupled mass-spectrometer, atomic absorption spectrometer to solve various analytical problems of geological science. In this work, we are presenting results of basic and following rare earth elements-REEs in some ores using XRF analysis. Samples from Luu river, Mushgia khudag, were prepared as glass and compressed types. The samples were measured by Wave Dispersion X-ray Spectroscopy- WDXRF PHILIPS PW-2400 with Rh anode, LiF-200 crystal analyzer, 150 μm collimator Duplix Xe counting proportional to the flux and Energy Dispersion X-ray Spectroscopy-EDXRF OPTIC with 145eV energy resolution for 5.9 keV Mn Kα, Si(Li) detector with 25μm Be window.

Beam monitoring in synchrotron radiation or free electron laser facilities is extremely important for calibration and diagnostic issues. Position sensitive broad-band X-ray detector based on InGaAs/InAlAs quantum well detector had been tested with collimated monochromatic X-ray beams and Synchrotron Radiations [1-4]. Their direct, high electron mobility and low energy band gap renders them capable of detecting photons ranging from visible to X-ray at room temperature. In this work, we simulated behavior of quantum states inside the quantum well with different width (5-50 nm) and δ-doping with silicon concentration (0-1.83x1018). The simulation shows, a number of states changes from 1 to 7 while the well width increasing. Si doping contributes to the electron density inside the quantum well. Therefore, the electron concentration increases in higher Si-doping concentration.

Due to the high atomic number, low band gap and high electron mobility of III-IV semiconductors, the use of metamorphic InGaAs/InAlAs quantumwell-based deviceswas proposed for fast pixelated photon detectors. In thiswork, we are presenting a double side-segmented quantum well (QW) device, discussing its spatial resolution and analysing the crosstalk between pixels. The fabricated devices were tested with needle-shaped beams of synchrotron radiation with different energies and spot sizes. The position of the synchrotron radiation was estimated with a 1.3-m precision. The charge spread in the material and related crosstalk function between pixels were extracted from the position estimation measurements of the photon beams. The results show that the cross-talk between pixels is actually responsible for the different resolutions obtained, regardless of the experimental conditions, pointing out the importance of the geometry of the fabricated devices. Furthermore, it has been observed that the QW pixelation is mandatory for hybrid detector technology.