• Computers and Concrete
• /
• v.33 no.2
• /
• pp.175-193
• /
• 2024

Researchers have embarked on an active investigation into the feasibility of adopting alternative materials as a solution to the mounting environmental and economic challenges associated with traditional concrete-based construction materials, such as reinforced concrete. The examination of concrete's mechanical properties using laboratory methods is a complex, time-consuming, and costly endeavor. Consequently, the need for models that can overcome these drawbacks is urgent. Fortunately, the ever-increasing availability of data has paved the way for the utilization of machine learning methods, which can provide powerful, efficient, and cost-effective models. This study aims to explore the potential of twelve machine learning algorithms in predicting the tensile strength of geopolymer concrete (GPC) under various curing conditions. To fulfill this objective, 221 datasets, comprising tensile strength test results of GPC with diverse mix ratios and curing conditions, were employed. Additionally, a number of unseen datasets were used to assess the overall performance of the machine learning models. Through a comprehensive analysis of statistical indices and a comparison of the models' behavior with laboratory tests, it was determined that nearly all the models exhibited satisfactory potential in estimating the tensile strength of GPC. Nevertheless, the artificial neural networks and support vector regression models demonstrated the highest robustness. Both the laboratory tests and machine learning outcomes revealed that GPC composed of 30% fly ash and 70% ground granulated blast slag, mixed with 14 mol of NaOH, and cured in an oven at 300°F for 28 days exhibited superior tensile strength.

• Asian-Australasian Journal of Animal Sciences
• /
• v.21 no.6
• /
• pp.861-867
• /
• 2008

The objective of this study was to evaluate the effect of exogenous ghrelin on the behaviors, weight gain, and feed intakes of weanling piglets. A total of 25 pairs of Duroc$\times$Landrace$\times$Large White piglets weaned at 21 days of age were used in this experiment which finished on day 36. Each pair of healthy piglets from the same litter with similar body weight and of the same gender were selected and randomly arranged to ghrelin or control groups. Thus, there were 50 piglets (ghrelin 25; control 25) kept in 10 pens (ghrelin 5; control 5) and 5 piglets per pen. Initial body weight of the pigs did not differ between the control and ghrelin treatment ($7.43{\pm}0.17kg$; p = 0.81). Experimental pigs were infused with ghrelin ($1{\mu}g/d$ pig) via the marginal ear vein between 0750 and 0800 h at 22, 23, 24 days of age. Control pigs were infused with 0.9% saline. Feed consumption was measured on days 23, 24, 25, 29 and 36. Body weight was measured on days 22, 23, 24, 25, 29 and 36. Behavior data of individual piglets were collected by real-time observation from 0800-1500 h through remote supervisory equipment at 22, 23 and 24 days of age. The results indicated that ghrelin infusion could increase drinking (p<0.05) and lying behaviors (p<0.01) and decrease mounting behaviors (p<0.05). No significant influence of ghrelin was found on average daily weight gain (ADG) and average daily feed intake (ADFI) in this experiment (p>0.05). In conclusion, exogenous ghrelin by the method above and at the dosage of $1{\mu}g/d$ pig could cause a variety of behavioral effects, but not improve performance of weanling piglets.

• Journal of Korean society of Dental Hygiene
• /
• v.11 no.6
• /
• pp.923-938
• /
• 2011

Objectives : This study was attempted in order to grasp oral health level according to socio-demographic characteristics in elders in some communities, and to evaluate oral health status and its association. Methods : The subjects in this study were performed with 235 people, who were over 65 years and resided in Daejeon Province, from June 20 to July 10, 2011. An individual interview was held, and they got a dental checkup. As for data analysis, chi-square test, t-test, one-way ANOVA, pearson correlation were utilized. Methods : The subjects in this study were performed with 235 people, who were over 65 years and resided in Daejeon Province, from June 20 to July 10, 2011. An individual interview was held, and they got a dental checkup. As for data analysis, chi-square test, t-test, one-way ANOVA, pearson correlation were utilized. Results : The older age in the whole research subjects and the lower educational level led to the less remaining teeth and the larger missing teeth index. The decayed missing filled teeth index and the decayed missing filled teeth rate were higher in more women and older age and in the lower educational level. Tooth mortality rate was higher in the older age, the lower educational level, and the group of living together with spouse. The maxillary-mandibular fixed-bridge status in the mouth was indicated to be the highest in the full-denture mounting ratio as for elders in over 80 years old. Oral Health Impact Profile(OHIP-14) average score was $56.05{\pm}11.64$ in the whole research subjects The decayed missing filled teeth index and the decayed missing filled teeth rate showed significantly positive correlation with the decayed missing filled teeth rate, tooth mortality rate and showed significantly negative correlation with OHIP-14. Tooth mortality rate showed significantly negative correlation with OHIP-14 Oral Health Impact Profile(OHIP-14) showed significantly positive correlation with its factors. Conclusions : Accordingly, the policy effort is considered to be necessary that implements in elders in order to spend active senescence, and that elders' health and oral-health behavior can be implemented continuously and preventively through classification according to elders' physical function.

• Asian-Australasian Journal of Animal Sciences
• /
• v.21 no.10
• /
• pp.1411-1415
• /
• 2008

The purpose of the present study was to determine the onset of breeding season, the occurrence of silent and true heats and the duration of estrus in female Markhoz goats of the Kurdistan province in Iran. Ten, 3 years-old Markhoz does with an average weight of $34.05{\pm}2.62kg$ and with one kidding record, were used. The goats were maintained in an open barn under constant nutritional levels and natural photoperiod. One aproned buck was used twice a day every 12 h to detect estrus from mid August to early January. For the determination of the onset of reproductive activity as well as occurrence of silent heat, blood samples were collected every 10 days, from the beginning of the experiment. After $2^{nd}$ standing heat, blood samples were obtained twice a week in order to assess luteal activity and the length of estrous cycles. In this study, estrous behavior was observed including sniffing, vocal exchange, following courtship, flehman, standing heat and mounting. The results of the progesterone assay indicated that in this goat silent heats occur mostly in the early breeding season. The first standing heat was observed in mid-October which was considered as the onset of the breeding season. Duration of the estrous cycle and estrus was recorded as being $20.93{\pm}1.56days$ and $38.86{\pm}15.19h$, respectively. The correlation coefficient between length of daylight and occurrence of estrus was negative (r = -0.470) but not significant (p>0.05). The data showed that there was no significant effect of body weight on estrous cycles (first, second and third) and estrous periods (first, second, third and fourth). Progesterone levels were not significantly different in the first, second and third estrous cycles at days 0, 4, 10, 12, 14 and 19. The results of progesterone assay during the estrous cycle indicate that follicular and luteal phases last 4-5 and 14-15 days, respectively and the concentration of serum progesterone in these phases was $0.88{\pm}0.08$ and $7.44{\pm}0.26ng/ml$, respectively. The study concluded that Markhoz does could be considered as a breed with a short breeding season and an optimal estrous activity in autumn.

• Economic and Environmental Geology
• /
• v.54 no.2
• /
• pp.233-245
• /
• 2021

Many studies on the microstructures in rocks have been conducted using experimental methods with various equipment as well as natural rock studies to see the development of microstructures and understand their mechanisms. Grain boundary migration of mineral aggregates in rocks could cause grain growth or grain size changes during metamorphism or deformation as one of the main recrystallization mechanisms. This study suggests improved ways regarding the analog material experiments with reformed equipment to see sequential observations of these grain boundary migration. It can be more efficient than the existing techniques and carry out an appropriate microstructure analysis. This reformed equipment was implemented to enable optical manipulation by mounting polarizing plates capable of rotating operation on a stereoscopic microscope and a deformation rig capable of experimenting with analog materials. The equipment can automatically control the temperature and strain rate of the deformation rig by microcontrollers and programming and can take digital photomicrographs with constant time intervals during the experiment to observe any microstructure changes. The composite images synthesized using images by rotated polarizing plates enable us to see more accurate grain boundaries. As a rock analog material, norcamphor(C7H10O) was used, which has similar birefringence to quartz. Static grain growth and simple shear deformation experiments were performed using the norcamphor to verify the effectiveness of the equipment. The static grain growth experiments showed the characteristics of typical grain growth behavior. The number of grains decreases and the average grain size increases over time. These case experiments also showed a clear difference between the growth curves with three temperature conditions. The result of the simple shear deformation experiment under the medium temperature-low strain rate showed no significant change in the average grain size but presented the increased elongation of grain shapes in the direction of about 53° regarding the direction perpendicular to the shearing direction as the shear strain increases over time. These microstructures are interpreted as both the plastic deformation and the internal recovery process in grains are balanced by the deformation under the given experimental conditions. These experiments using the reformed equipment represent the ability to sequentially observe changing the microstructure during experiments as desired in the tests with the analog material during the entire process.