Scientific transaction of the National University of Mongolia. Physics

Эмнэлгийн рентген төхөөрөмжийн цацрагийн хамгаалалтын тооцоолол

ganzul tsengel — 2024-09-30

In this study, we performed radiation shielding calculations for the diagnostic X-ray equipment at Rekha Med Hospital. The lead thickness required for radiation protection, as determined by the methodology outlined in the National Council on Radiation Protection and Measurements (NCRP) Report No. 147, was approximately 2 mm. Air kerma measurements were taken outside the X-ray room to validate the shielding effectiveness with a 2 mm thick lead barrier installed along the walls. The results confirmed that the air kerma dose did not exceed the regulatory dose limit of 0.5 mSv/H in uncontrolled areas, indicating sufficient shielding.

NI-MH баттерейны багтаамж болон дотоод эсэргүүцэл тодорхойлох LabVIEW системийн хөгжүүлэлт

Dashnyam Gantulga — 2024-04-16

Энэ ажлаар дахин цэнэглэгддэг батарейны багтаамж болон дотоод эсэргүүцлийг хэмжих LabVIEW систем хөгжүүлсэн. Ингэхдээ Panasonic үйлдвэрийн AA хэмжээтэй Eneloop батарейны багтаамж, дотоод эсэргүүцлийг электроник ачаа (DL3021), програмчлагддаг тэжээлийн үүсгүүр (DP821), DAQ NI-9219 болон термохос ашиглан автоматаар хэмжиж авах аргыг боловсруулсан.

[ENGLISH]

In this work, a LabVIEW system was developed to measure the capacity and internal resistance of rechargeable batteries. In doing so, the capacity and internal resistance of Panasonic factory AA-size Eneloop batteries were automatically measured using an electronic load (DL3021), a programmable power source (DL3021), a DAQ NI-9219, and a thermocouple.

RAD01: Development of a NUMTEK RAD01 Low-Cost, Portable Digital Gamma Radiation Detector

Luvsanbat Khurelbaatar — 2024-04-15

Additive manufacturing and open-source affordable instruction provide equal opportunities. Therefore, it is possible to quickly, compactly, and cheaply make expensive, scarce, and large devices in the previous century. The Geiger-Muller tube is used for the primary sensing component proposed and incorporates digital signal processing to ensure accurate and reliable measurement of gamma radiation. The performance of the developed detector is evaluated through experimental testing and comparisons with commercially available radiation detection devices. The results demonstrate the detector's ability to provide precise and consistent measurements while remaining cost-effective. Moreover, its portability and user-friendly interface make it suitable for various applications, including environmental monitoring, nuclear safety, personal radiation exposure assessment, and, most importantly, educational purposes. This low-cost portable digital gamma radiation detector contributes to the field of radiation detection by presenting an accessible solution that addresses the financial limitations associated with conventional gamma radiation detectors.

ПЭТ-КT төхөөрөмжийн цацрагийн хамгаалалтын тооцоо

Munkhsaikhan Jargalsaikhan — 2024-04-15

In this study, the effective dose rate and shielding thickness for a PET/CT facility are calculated by the analytical formula and PHITS code. The calculations at 9 different points in the unshielded and shielded rooms of the PET/CT were performed and the results were compared. The dose administered and the workload were estimated to be 15mCi and 40 patients per week. The required barrier thickness based on the weekly dose limit is 100 µSv for the controlled areas and 20 µSv for uncontrolled areas, corresponding to the 1 mSv/year limit to the general public.

Гиперспектр буюу хэт олон сувагт “LCTF” камер ашиглан ургамлыг төрөл зүйлээр ангилан ялгах шинэ алгоритм

Bayartsetseg Oyungerel — 2024-04-10

Энэ судалгааны хүрээнд хэт олон сувагт LCTF (Liquid Crystal Tunable Filter) буюу шингэн кристалл шүүлтүүртэй камерын тусламжтай ургамлын зүйлийг түүний спектр шинж чанарт тулгуурлан ялгаж, навчны талбайн индекс LAI (Leaf Area Index) тооцож гаргах шинэ алгоритмыг туршин үзэв. 2022 оны 7-р сарын эхний долоо хоногт Хар Ямаат байгалийн нөөц газарт хэд хэдэн бодит талбарт LCTF камераар хээрийн ургамлуудын зургийг авч, цуглуулсан зурган мэдээллээс ургаж буй олон зүйлийн ургамлуудын гэрлийн ойлтын спектрийг дүрс боловсруулах аргаар ялгаж, түүгээр спектр сан үүсгэв. Үүсгэсэн сангийн мэдээллээс бид улаан хилийн зурваст тулгуурлан өвслөг ургамлын зүйлийн бүрдлийг тодорхойлох алгоритм туршиж үзсэн. Тухайн алгоритмаар навчны талбайн индексийг мөн тооцож гаргахад эрүүл ургамлыг хагдарсан өвс болон ургамал бус зүйлээс 95% дээш нийлэмжтэй ялгаж байна. Энэ ажлын үр дүнд ургамлын төрөл зүйлийг машинаар олон сувагт камерын тусламжтай өндөр нарийвчлалтай ялгах боломжтойг харуулж байна. Цаашид орчин үеийн хиймэл дагуул, дроноор авсан зургаас уг бидний хөгжүүлсэн алгоритмыг ашиглан хаана ямар төрөл зүйлийн ургамал хэр хэмжээгээр ургаж буйг ялгах боломж бүрдэх юм.

[ENGLISH]
Within the framework of this research, a new algorithm was designed to determine the plant’s red edge slope and the Leaf Area Index (LAI) based on their spectral characteristics using a hyperspectral LCTF (Liquid Crystal Tunable Filter) camera. In the first week of July 2022, we took pictures of field vegetation in several fields in the Khar Yamaat Nature Reserve with the LCTF camera. From the collected data, the light reflectance spectrum of many species of growing plants was distinguished with the help of image processing, and with that, we created a spectrum dataset of 21 different species. From the generated dataset, we designed an algorithm to determine plant species or dry grass based on the red edge slope, which works with approximately 95% accuracy. The algorithm also calculates the leaf area index, and healthy plants are distinguished from damaged grass and non-plant species. The results of this work demonstrate that vegetation can be classified by vegetation’s red edge slope using hyperspectral cameras. In the future, it will be possible to determine the location and number of growing plants using the algorithm we developed on the images taken by modern satellites and drones.

Академич Н.Содномын мэндэлсний 100 жилийн ойд зориулсан “Рентген шинжилгээ” олон улсын эрдэм шинжилгээний зургаадугаар хурал

Болортуяа Д — 2023-12-21

The Nuclear Research Center organized the sixth international conference on "X-ray Analysis" on August 28-30, 2023. The conference took place in a hybrid format, combining in-person and virtually. More than 60 scientists from Mongolia, Russia, Japan, the USA, Spain, Italy, India, and Argentina participated in the conference. The conference featured 24 oral presentations and 14 poster presentations covering both fundamental and applied research. These presentations delved into the latest developments in X-ray analysis, current trends, theoretical and methodological calculations, as well as applications in the fields of environment, geology, mining, substance structure, and radiation processing. This review article provides a summary of the significant and interesting presentations delivered at the conference

Лантаны феррит (LaFeO3) нэгдлийн цахилгаан химийн шинж чанарын судалгаа

Nomin Bayansan — 2024-01-03

Энэхүү судалгааны ажилд перовскит бүтэцтэй лантан феррит (LaFeO₃) нэгдлийн бүтэц, оптик шинж чанарыг хэт ягаан туяаны спектроскопоор (UV-vis spectroscopy), цахилгаан химийн шинж чанарыг циклик вольтамметрийн (Cyclic voltammetry) аргуудаар тодорхойлов. Үр дүнд LaFeO₃ нэгдлийн кристаллитийн хэмжээ D = 38.9 нм, эгэл үүрийн эзлэхүүн V = 241.871 , кристалл бүтэц нь орторомбик бүхий Pnma огторгуйн групптэй байсан ба хэт ягаан туяаны спектрометрийн үр дүнгээс хориотой бүсийн өргөнийг тооцоолоход E_g= 2.26 эВ байсан. Циклик вольтамметрийн хэмжилтийн үр дүнд цахилгаан багтаамжийг тооцоолоход C_s = 1.96 Ф/г байв.

Түлшээ үржүүлэн шатаах хурдан реакторын нейтроны тоог нэмэгдүүлэх боломжууд

Одмаа — 2023-12-22

The breed-and-burn fast reactor utilizes depleted or natural uranium fuel and the fissile isotopes generate from fertile isotopes while the fissile ones burn. So, it has an advanced nuclear reactor with technological advantages to utilize uranium resources effectively as well as to reduce the amount of spent nuclear fuel. The integration of neutron number in a reactor core is determined by the difference between the total number of produced and absorbed neutrons, including lost neutrons in a core during burnup. While the neutron balance is high, the fuel breeding process works effectively. The objective of the research work is to find ways to increase the neutron balance in a reactor core.

In the present work, the effect of some design parameters such as pin pitch, cladding thickness and density on neutron balance was studied for infinite one fuel cells with different materials.