• Journal of the Korean Institute of Gas
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• v.15 no.5
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• pp.25-30
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• 2011

Biogas obtained from the biodegradable organic wastes in an anaerobic digester consists of $CH_4$ and inert gases such as $CO_2$ and $N_2$. Since the composition of biogas varies by anaerobic digester conditions and the origin of wastes, it is necessary to respond to these variations so as to make stable combustion and accomplish high efficiency when it is used as a fuel for power generating SI engines. In this study, efforts have been made to investigate the effect of changes in the calorific values of biogas on the engine performance and exhaust characteristics. The biogas was simulated by supplying of $CH_4$ with $N_2$ dilution of various ratios, and ECM was developed to achieve accurate control of ignition and combustion. The results show that as the $CH_4$ concentration of the biogas decreases, the optimal spark timing is advanced due to the elevated thermal capacity and lowered $O_2$ concentration of the in-cylinder charge. Furthermore, since combustion temperature was reduced by increased inert gas, $NO_x$ emissions decreased, whereas THC emissions increased.

• Proceedings of the Korea Information Processing Society Conference
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• 2002.11c
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• pp.2265-2268
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• 2002

인터넷 사용자들의 기하급수적인 증가와 웹 페이지의 폭발적인 증가로 인하여 정보공유를 위한 인터넷에서 효율적으로 원하는 정보를 발견하고 이용하기에 매우 힘든 상황에 처해있다. 따라서, 이러한 문제점들을 근본적으로 해결하기 위한 노력의 일환으로 기계가 이해하고 추론할 수 있는 시맨틱 웹이 등장하였다. 시맨틱 웹과 관련된 여러 가지 기술들 중 시맨틱 웹 서비스는 사용자에게 현재의 인터넷 환경에서 제공할 수 있는 서비스보다 향상된 고품질의 서비스를 제공하는 것을 목적으로 삼고 있다. 이러한 시맨틱 웹 서비스는 웹 서비스의 발견, 실행 및 구성으로 구성된다. 본 논문에서는 시맨틱 웹 서비스를 자동화하기 위한 노력의 일환으로서 시맨틱 웹에서 웹 서비스를 구성하는 문제에 대하여 언급한다. 시맨틱 웹 서비스 구성문제는 사용자의 요구사항을 충족시키기 위하여 다양한 웹 서비스들을 조합하는 문제이다. 그러나, WSFL, X-LANG 및 BPEL4WS 그리고, DAML-S와 같은 웹 서비스 구성문제에 대한 일련의 노력들에서는 사용자 요구사항에 대한 검증이나 서비스의 품질에 대한 사항들을 확인 및 제공할 수 있는 방법들이 없다. 따라서, 본 논문에서는 시맨틱 웹 서비스 구성문제와 관련된 상기와 같은 문제점들을 해결할 수 있는 방법론을 제시한다. 본 논문에서 제시된 방법론에서는 시맨틱 웹 구성문제를 제약만족문제로 변환함으로써 제약만족문제에 있어 늘리 알려진 다양한 알고리즘들을 활용할 수 있는 장점들이 있을 뿐만 아니라 사용자들의 요구사항에 대한 검증과 서비스의 품질을 확인할 수 있는 장점들이 있다.의 위상변화에 대한 적응성을 높일 수 있도록 한다. SQL Server 2000 그리고 LSF를 이용하였다. 그리고 구현 환경과 구성요소에 대한 수행 화면을 보였다.ool)을 사용하더라도 단순 다중 쓰레드 모델보다 더 많은 수의 클라이언트를 수용할 수 있는 장점이 있다. 이러한 결과를 바탕으로 본 연구팀에서 수행중인 MoIM-Messge서버의 네트워크 모듈로 다중 쓰레드 소켓폴링 모델을 적용하였다.n rate compared with conventional face recognition algorithms. 아니라 실내에서도 발생하고 있었다. 정량한 8개 화합물 각각과 총 휘발성 유기화합물의 스피어만 상관계수는 벤젠을 제외하고는 모두 유의하였다. 이중 톨루엔과 크실렌은 총 휘발성 유기화합물과 좋은 상관성 (톨루엔 0.76, 크실렌, 0.87)을 나타내었다. 이 연구는 톨루엔과 크실렌이 총 휘발성 유기화합물의 좋은 지표를 사용될 있고, 톨루엔, 에틸벤젠, 크실렌 등 많은 휘발성 유기화합물의 발생원은 실외뿐 아니라 실내에도 있음을 나타내고 있다.>10)의 $[^{18}F]F_2$를 얻었다. 결론: $^{18}O(p,n)^{18}F$ 핵반응을 이용하여 친전자성 방사성동위원소 $[^{18}F]F_2$를 생산하였다. 표적 챔버는 알루미늄으로 제작하였으며 본 연구에서 연구된 $[^{18}F]F_2$가스는 친핵성 치환반응으로 방사성동위원소를 도입하기 어려운 다양한 방사성의 약품개발에 유용하게 이용될 수 있을 것이다.었으나

• Proceedings of the Korean Vacuum Society Conference
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• 2000.02a
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• pp.126-126
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• 2000

다이아몬드상 카본(DLC) 필름은 경도가 높고, 마찰계수가 낮다는 장점을 가지고 있기 때문에 내마모성 코팅이나 윤활성코팅에 응용을 위한 연구가 활발히 진행중이다. 하지만 마찰계수가 주변환경에 매우 큰 영향을 받는다는 단점이 있다. 이러한 단점은 DLC필름의 응용에 대한 저해 요인이 되며, 이 점을 보완하기 위해서 DLC 필름에 Si을 첨가하는 연구들이 진행되고 있다. 본 실험에서는 r.f-PACVD 법을 이용하여 Si이 첨가된 DLC 필름의 주위 환경 변화에 따른 마찰특성의 변화를 연구하였다. 사용한 반응 가스는 벤젠(C6H)과 희석된 Silane(SiH4 : H2 = 10 : 90)이며, 희석된 Silane과 벤젠의 첨가비율을 조절하여 필름내 Si의 함량을 조절하였고, 증착시 바이아스의 전압은 -400V로 하였다. 마찰테스트는 Ball-on-Disk type의 조건에서 대기, 건조공기, 진공의 세가지 분위기에서 마찰테스트를 실행하였다. 실험결과 마찰계수는 건조공기, 대기, 진공의 순으로 증가하였고, 필름내에 포함되어 있는 Si의 양이 증가할수록 마찰계수는 낮고 안정한 값을 나타내었다. Tribochemiacal 분석과, ball과 track의 전자현미경 사진 분석 결과, 진공에 비해서 건조공기와 대기중에서 마찰계수가 낮은 것은 DLC 필름내에 마모 track 중심부에 Si-C-O 계의 화합물이 형성되어, 이 화합물이 마찰계면에 존재하여 마찰계수를 낮추었음을 확인하였다. 그리고 대기중에서 실험한 경우, 습기의 존재로 인해 마모입자가 볼의 표면에서 엉김으로써 건조공기의 상태에서 보다 높은 마찰저항을 갖게 됨으로 인하여 마찰계수가 높아짐을 알 수 있었다.a)는 as-deposit 상태이며, 그림 1(b)는 45$0^{\circ}C$, 60min 열처리한 plan-view TEM 사진이다.dical의 영향을 조사하였으며 oxygen radical의 rf power에 따른 변화는 OES(Optical emission spectroscopy)를 사용하였다. 너무 적은 oxygen ion beam flux나 oxygen radical은 film의 전도도 및 투과도를 저하시켰고 반면 너무 과도한 flux의 증가 시는 전도도는 감소하였고 투과도는 증가하는 경향을 보였다. 기판에 도달하는 oxygen ion flux는 faraday cup을 이용하여 측정하였으며 증착된 ITO film은 XPS, UV-spectrometer, 4-point probe를 이용하여 분석하였다. 때문으로 생각되어진다. 또한, 성장 온도가 낮아짐에 따라 AlGaN의 성장을 저해하기 때문으로 판단된다. 성장 온도 변화에 따라 성장된 V의 구조적 특성 및 표면 거칠기 변화를 관찰하여 AlGaN의 성장 거동을 논의하겠다.034, 0.005 정도로 다시 감소하였다. 박막의 유전율은 약 35 정도의 값을 나타내었으며 X-선 회절 data로부터 분석한 박막의 변형은 증온도에 따라 7.2%에서 0.04%로 감소하였고 이 이경향은 유전손실은 감소경향과 일치하였다.는 현저하게 향상되었다. 그 원인은 SB power의 인가에 의해 활성화된 precursor 분자들이 큰 에너지를 가지고 기판에 유입되어 치밀한 박막이 형성되었기 때문으로 사료된다.을수 있었다.보았다.다.다양한 기능을 가진 신소재 제조에 있다. 또한 경제적인 측면에서도 고부가 가치의 제품

• Fisheries and Aquatic Sciences
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• v.21 no.2
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• pp.6.1-6.10
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• 2018

The intention of this study was to identify the bacterial pathogens infecting Oreochromis niloticus (Nile tilapia) and Clarias gariepinus (African catfish), and to establish the antibiotic susceptibility of fish bacteria in Uganda. A total of 288 fish samples from 40 fish farms (ponds, cages, and tanks) and 8 wild water sites were aseptically collected and bacteria isolated from the head kidney, liver, brain and spleen. The isolates were identified by their morphological characteristics, conventional biochemical tests and Analytical Profile Index test kits. Antibiotic susceptibility of selected bacteria was determined by the Kirby-Bauer disc diffusion method. The following well-known fish pathogens were identified at a farm prevalence of; Aeromonas hydrophila (43.8%), Aeromonas sobria (20.8%), Edwardsiella tarda (8.3%), Flavobacterium spp. (4.2%) and Streptococcus spp. (6.3%). Other bacteria with varying significance as fish pathogens were also identified including Plesiomonas shigelloides (25.0%), Chryseobacterium indoligenes (12.5%), Pseudomonas fluorescens (10.4%), Pseudomonas aeruginosa (4.2%), Pseudomonas stutzeri (2.1%), Vibrio cholerae (10.4%), Proteus spp. (6.3%), Citrobacter spp. (4.2%), Klebsiella spp. (4.2%) Serratia marcescens (4.2%), Burkholderia cepacia (2.1%), Comamonas testosteroni (8.3%) and Ralstonia picketti (2.1%). Aeromonas spp., Edwardsiella tarda and Streptococcus spp. were commonly isolated from diseased fish. Aeromonas spp. (n = 82) and Plesiomonas shigelloides (n = 73) were evaluated for antibiotic susceptibility. All isolates tested were susceptible to at-least ten (10) of the fourteen antibiotics evaluated. High levels of resistance were however expressed by all isolates to penicillin, oxacillin and ampicillin. This observed resistance is most probably intrinsic to those bacteria, suggesting minimal levels of acquired antibiotic resistance in fish bacteria from the study area. To our knowledge, this is the first study to establish the occurrence of several bacteria species infecting fish; and to determine antibiotic susceptibility of fish bacteria in Uganda. The current study provides baseline information for future reference and fish disease management in the country.

• Journal of the Korean Vacuum Society
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• v.14 no.4
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• pp.215-221
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• 2005

Thermoelectric bismuth telluride thin films were prepared on $SiO_{2}$/Si substrate with co-sputtering of bismuth and tellurium targets. The effects of deposition temperature on surface morphology, crystallinity and electrical transport properties were investigated. Hexagonal crystallites were clearly visible at the surface of films deposited above $290 ^{\circ}C$. Change of dominant phase from rhombohedral $Bi_2Te_3$ to hexagonal BiTe was confirmed with X-ray diffraction analysis. The deviation from stoichiometric composition at high deposition temperature resulted in the change of structural and electrical characteristics. Seebeck coefficients of all samples have negative value, indicating the prepared $Bi_XTe_Y$ films are n-type thermoelectric. Optimum of Seebeck coefficient and power factor were obtained at the deposition temperature of $225 \^{circ}$C (about -55 $\mu$V/K and $3\times10^{-4}$ W/$k^{2}$m, respectively). Deterioration of thermoelectric properties at higher temperature.

• Biomedical Science Letters
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• v.2 no.2
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• pp.133-151
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• 1996

After cardiac surgery, it has been recognized that various complications were associated with injured humoral and cellular immunity by cardiopulmonary bypass(CPB). Especially, in postoperative pulmonary dysfunction, transpulmonary leukostasis followed complement activation and inflammatory responses are major pathogen. Some studies have showed that pretreated-corticosteroids before CPB protected postoperative pulmonary dysfunction. Corticosteroids may inhibit complement and leukocyte activation. On based previous studies, present investigator determined changes of leukocyte counts and transpulmonary leukostasis during cardiac surgery and postoperative periods. For the evaluation of postoperative pulmonary function and edema, $PaO_2$ and chest X-ray were compared between pre-CPB and post-CPB. Fever and other parameters were also observed postoperatively. The aim of this study was to define for the prophylactic effects of corticosteroid(Solu-Medrol: 30mg/kg) on all the researched parameters. This study was prospectively designed with randomized-blind fashion for 50 patients undergoing cardiac surgery. According to the purpose of study, all patients were divided into placebo and steroid group. : Placebo group was 25 patients received normal saline(not corticosteroid), and steroid group was 25patients received corticosteroid(Solu-Medrol: 30mg/kg) before initiation of CPB. The results of study were summarized as follows. 1. Total peripheral leukocyte counts decreased significantly at 5 minutes of CPB in all patients(P<0.01), and began to increase progressively at later periods of CPB with neutrophilia. The significant rise remained at postoperative 7th day(P<0.05). 2. During partial CPB, transpulmonary leukostasis occurred in placebo group(P<0.001), whereas it was prevented in steroid group. 3. In both groups, peripheral lymphocyte counts were stable during CPB, but began to reduce at time of intensive care unit(ICU) and the lymphocytopenia remained until postoperative 3rd day. The lymphocyte counts recovered on postoperative 7th day. 4. In both groups, peripheral counts of monocyte were relatively stable in the early peroid of CPB, and increased gradually in the later periods of CPB. This significant monocytosis remained throughout postoperlative periods(P<0.05). 5. The mean value of postoperative $paO)_2$ was lower than that of pre-CPB in placebo group(P=0.01) but didn't significant in steroid group(P=0.90). In the incidence of pulmonary edema signs and fever, placebo group was higher than steroid group(P=0.001, p=0.01, respectively). However mechanical respiratory supporting and care periods at intensive care unit were not significant difference between two groups(P>.0.05).With the above results, the investigator concluded that leukocyte activation and pulmonary sequestration were caused by cardiac surgery with CPB and demonstrated that high dose corticosteroid will provide prophylactic effect for pulmonary leukostasis and higher neutrophilia. These effects may ameliorate postoperative pulmonary dysfunction and contribute to postoperative less morbidity. However, further study should be performed because postoperative lymphocytopenia continued for 3 days in both groups, which may suspected damage or suppression of cell-mediated immunity with used corticosteroid.

• The korean journal of orthodontics
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• v.28 no.1 s.66
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• pp.29-41
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• 1998

Despite orthodontic treatment(tooth moving) is dynamic act many orthodontists have used mainly static evaluation method for evaluating effectiveness of the orthodontic appliances. They want to find which is better appliance, especially in the treatment results and treatment period when they chose one appliance from sugessted appliances for obtaining same treatment goal. The author and colleagues invented and manufactured new machine for getting information about the relative effectiveness from many suggested orthodontic appliances and we named it Calorific machine. We used this Calorinc machine to find the relative differences about tooth moving mechanism and tooth moving time between the Burstone's PLA(single force mechanism) and Molar-up's PLA(couple mechanism) for correcting the posterior cross bite. We measured the distance of tooth moving on the occlusal X-ray film and recorded the moving time of the anchored(control elctro-thermal tooth) and lingually tipped lower second molars(experimental electro-thermal tooth) and then processed paired t-est by SAS program. The results were as follows. 1. Molar-up's PLA showed more extrusive and horizontal movement than Burstone's PLA at the lingually tipped molar(p=0.0000). 2. There is no finding of tooth movement by Molar-up's PLA at the uprighted molar(p=o.3475) but Burstone's PLA showed a little change(0.2 m) at the same molar(p=0.0001). 3. Burstone's PLA took 17.8 minutes for tooth moving but Molar-up's PLA took only 3.8 minutes(p=0.0001)

• Korean Journal of Microbiology
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• v.30 no.2
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• pp.88-95
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• 1992

The genetically engineered microorganisms (GEMS) could be released accidentally or ii)rexperimental purposes, as the genetic engineering, technique ha:. become very popular inany laboratories of biological sciences. But there have been littlt: informations on transkrbehavior of the genetically ~nodified genes in the natural en\ironmentx. In this stutly.antibiotic resistant bacteria were isolated from nat.ural waters. and then GEM strains wereconstructed i'rom the natural isolate (NI) by ~noclification oi' the Km' plasmitl. Thetransferability of the plasmids in the GEM and NI strains were examinetl by con-jugationin Luria-Bertani broth :it 30$^{\circ}$C. Also the cff'ccts 01' mating strain and pH on their transferfrequency and rearrangement of the plasmids in tl-~ec o~ijugantsM ere comp:irati\ely stuclictl.I'hc transkr frequency of Km' plasmid in donor of GEM and N1 strains wah similar a.;about 10 ' when co~ljugation was conducted wit11 M'I'I strain is recipient at pH 7. butthat of 1)KCOOI was lowered to 1.2X 10 '. And when the lab. stlain was uhccl as recipient.the transfer tendency of the plasmid was about same in both (;EM and NI strains usedas donor. All thc tionor 5trains. except for I)KC601. showecl the Ilighcs~ frequency of about10 ' at pH 7 and the frequcncics were lowered at both pH 5 and 9. Hut the mocliliedKm' plasmid in the cloned strain of DKC601 was transferred hy very low frequency of10 "at pH 5 ant1 7 comparing to other GEM strains. especiall! any co~~.jugantws ere notobtained at pH 4 and 9 even after conjugation for 6 hours. Rearrangement of the plasmidstranskrred into the lab. strain was not found in the conjugants. I\ulcornerut a lot of rearrangclncntwas ohservecl nlhen they were transferred into the NI strain. Such a rearrangement wasmore severe when donor was GEM strain rather then NI strain Hut such ;r phenomenonwas less affected by p!-l values.r phenomenon was less affected by p!-l values.

• Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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• 2001.06a
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• pp.1121-1121
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• 2001

A previous study (Berzaghi et al., 2001) evaluated the performance of 3 calibration methods, modified partial least squares (MPLS), local PLS (LOCAL) and artificial neural networks (ANN) on the prediction of the chemical composition of forages, using a large NIR database. The study used forage samples (n=25,977) from Australia, Europe (Belgium, Germany, Italy and Sweden) and North America (Canada and U.S.A) with reference values for moisture, crude protein and neutral detergent fibre content. The spectra of the samples were collected using 10 different Foss NIR Systems instruments, only some of which had been standardized to one master instrument. The aim of the present study was to evaluate the behaviour of these different calibration methods when predicting the same samples measured on different instruments. Twenty-two sealed samples of different kind of forages were measured in duplicate on seven instruments (one master and six slaves). Three sets of near infrared spectra (1100 to 2500nm) were created. The first set consisted of the spectra in their original form (unstandardized); the second set was created using a single sample standardization (Clone1); the third was created using a multiple sample procedure (Clone6). WinISI software (Infrasoft International Inc., Port Mathilda, PA, USA) was used to perform both types of standardization, Clone1 is just a photometric offset between a “master” instrument and the “slave” instrument. Clone6 modifies both the X-axis through a wavelength adjustment and the Y-axis through a simple regression wavelength by wavelength. The Clone1 procedure used one sample spectrally close to the centre of the population. The six samples used in Clone 6 were selected to cover the range of spectral variation in the sample set. The remaining fifteen samples were used to evaluate the performances of the different models. The predicted values for dry matter, protein and neutral detergent fibre from the master Instrument were considered as “reference Y values” when computing the statistics RMSEP, SEPC, R, Bias, Slope, mean GH (global Mahalanobis distance) and mean NH (neighbourhood Mahalanobis distance) for the 6 slave instruments. From the results we conclude that i) all the calibration techniques gave satisfactory results after standardization. Without standardization the predicted data from the slaves would have required slope and bias correction to produce acceptable statistics. ii) Standardization reduced the errors for all calibration methods and parameters tested, reducing not only systematic biases but also random errors. iii) Standardization removed slope effects that were significantly different from 1.0 in most of the cases. iv) Clone1 and Clone6 gave similar results except for NDF where Clone6 gave better RMSEP values than Clone1. v) GH and NH were reduced by half even with very large data sets including unstandardized spectra.

• Advances in concrete construction
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• v.10 no.4
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• pp.301-310
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• 2020

The following paper concentrates on the objective of studying the influences of extent of duration and temperature on the Pozzolanic properties as well as reactivity of locally existing natural clay of Nai Gaj, district Dadu, Sindh Pakistan. The activation of the clay only occurs through heating when temperature in a furnace chamber reaches 600, 700 and 800oC for 1, 2 and 3 hours and at 900 and 1000℃ for 1 and 2 hours. Furthermore, the strength activity index (SAI) of advanced pozzolanic material happens to be identified through 20% cement replacement for different samples of calcined clay as per ASTM C-618. The compressive strength test of samples had been operated for 7 and 28-days curing afterwards. The maximum compressive strength had been seen in mix E in which cement was replaced with clay calcined at 700℃ for 1 hour that is 27.05 MPa that is 24.31% more than that of control mix. The results gathered from the SAI verdicts the optimal activation temperature is 700℃ within a one-hour time period. The SAI at a temperature of 700℃ with a one-hour duration at 28 days is 124.31% which happens to satisfy the requirements of the new Pozzolanic material, in order to be applied in mortar/concrete (i.e., 75%). The Energy- dispersive spectrometry (EDS) along with the X-ray diffraction (XRD) have been carried out in means of verifying whether there is silica content or amorphous silica present in metakaolin that has been developed. The findings gathered from the SAI were validated, as the analysis of XRD verified that there is in fact Pozzolanic activity of developed metakaolin. Additionally, based on observation, the activated metakaolin holds a significant influence on the increase in mortar's compressive strength.