Thermal properties of Malaysian cohesive soils

The thermal properties of soils surrounding energy piles are required for the efficient and optimal design of shallow geothermal energy pile systems. In this study, the thermal conductivity, thermal resistivity and volumetric specific heat of two types of Malaysian cohesive soil were obtained through a series of laboratory experiments using a thermal needle probe. This study was conducted to determine the effect of moisture content on the thermal conductivity, thermal resistivity and volumetric specific heat values of the cohesive soil at a given value of soil density. For soils with low to medium moisture content, a linear increase in the thermal conductivity and volumetric heat capacity was observed as the moisture content gradually increased, while the thermal resistivity values of the soil had decreased. Meanwhile, for soils with high moisture content, the thermal conductivity was observed to have decreased, and a marked increase was seen in the thermal resistivity. This is due to the disruption of the thermal flow continuity in the soil matrix with the presence of moisture in the soil which adversely affects the thermal conductivity

Keefektivan Model Pembelajaran Student Teams Achievement Division (Stad) Pada Pembelajaran Ekonomi Berbasis Konstruktivis Terhadap Hasil Belajar Siswa

Learning is a process of changing the behavior through experience and training. The changing of behavior involves knowledge, skills, attitudes and even all aspects of the organism or individual himself. Unfortunately, many students have difficulty in understanding the abstract concepts of a subject. Therefore, we need the alternative learning model to overcome the difficulties in learning. One of the learning models is Student Team Achievement Division (STAD) learning model. STAD model is a cooperative learning model encouraging students to actively discover knowledge through the skills process. The objective of this study is to determine the average difference of students\u27 learning outcomes through cooperative learning model with STAD type and the expository model on the subject material of Market Price Formation. The population of this study was all VIII Classes of SMP Negeri 1 Randudongkal in the academic year of 2007/2008. There were 7 classes consisted of 292 students. Samples are taken randomly, the first group was VIIIC students as the experimental group using STAD learning model, whereas the second group was students in VIIID class as the control group. Data was collected by test method, and then analyzed by the mean difference test. The results showed that there was a significant mean difference in students\u27 learning outcomes. The average score for experimental group was 75.93 and for the control group was only 71.36. Based on this study, it is suggested to use STAD learning model based on constructivism in teaching and learning process because it can encourage students to be active with their own skills

Physicochemical and Microstructural Characterization of Klias Peat, Lumadan POFA, and GGBFS for Geopolymer Based Soil Stabilization

Peat soils are highly heterogeneous and considered problematic because they have a high moisture content and low shear strength. It requires stabilization to enhance its engineering properties before it is transformed into a viable construction material. The use of geopolymers as stabilizer materials for weak soils has been on the rise recently due to their low carbon footprint compared to the use of conventional stabilizer materials like cement. Geopolymerization occurs as a result of the alkali activation of aluminosilicate materials. In this study, peat soil and the aluminosilicate materials Palm Oil Fuel Ash (POFA) and Ground Granulated Blast Furnace Slag (GGBFS) are characterized to assess their suitability as geopolymer precursor materials. A series of laboratory studies were carried out to determine the physicochemical properties of the materials, such as particle size distribution, moisture and organic content, specific gravity, pH, and electrical conductivity. Furthermore, the XRD, XRF, and FESEM tests were carried out to ascertain the mineral characteristics, elemental chemical composition, and morphological characteristics of these materials, respectively. The peat soil is classified as hemic peat with sufficient aluminosilicate content (Si/Al ratio of 2.11). The POFA is identified as Class F pozzolan with adequate Si+Al+Fe oxide content (67.9%), as stipulated by ASTM C618. The GGBFS material was found to be appropriate for geopolymer production, with a Si/Al ratio of 2.17, a hydration modulus of 2.38 (good hydration), and a basicity coefficient of 1.32 (alkaline material favorable for geopolymerization). Based on the geopolymer precursor material suitability assessment criteria, all the materials assessed were deemed suitable for geopolymerization, and the effectiveness of POFA-GGBFS geopolymer to improve peat soil properties should be studied in depth. At present, there are limited studies pertaining to the use of alkali-activated POFA-GGBFS blends to improve peat soil properties. As a result of this material characterization phase, planned works involving the compressive strength testing program on alkali-activated POFA-GGBFS-peat soil blends at ambient temperature will be carried out in the near future. The eventual aim of this research is to remediate the peat soil to be repurposed as road subgrade material. Doi: 10.28991/HIJ-2023-04-02-07 Full Text: PD

Topographic survey and modelling using photogrammetry: A comparison against Electronic Distance Measurement (EDM) method

Topographic surveying has been an important companion to the civil engineer in the development of human civilisation since ancient history. It is used to map terrestrial features on the ground along with its contour heights. Application of this can be seen in the establishing land boundaries and setting out construction projects. Conventional methods of surveying range from ground field methods such as the use of total station to aerial surveys such as photogrammetry or LiDAR. This study looks to assess the feasibility of aerial photogrammetry using UAVs as a replacement to the conventional EDM survey using total stations. This objective was achieved by carrying out both photogrammetric and EDM surveys on a 350m long stretch of highway. The resulting survey data were processed to produce two comparative TIN surfaces of the highway which were then superimposed together and compared for accuracy. It could be observed that on plan view, both surfaces were quite closely matched with a maximum difference of less than 0.4m and a low standard deviation. In elevation view, however, the differences were larger with maximums of 5.0m, accompanied by large standard deviations. RMS error analysis carried out also correlate with the findings

Analisis Keterkaitan Antara Aktivitas Kendaraan Bermotor dengan Tingkat Kebisingan: Studi Kasus di Jalan Gatot Subroto, Kota Palu

The elevation of mobility in Palu has evolved into a new noise issue. Noise from motorized vehicles has quite an impact on the tranquility of areas that directly intersect with the highway. Gatot Subroto Axis Road is an instance of a congested road as public facilities such as educational institutions take the crowd of the area. The study aims to analyze the relationship of vehicle activities toward noise level at Gatot Subroto. The research method uses field measurement by a sound level meter (SLM), tripod, and counter. Noise sampling standards refer to SNI 8427:2017 regarding measuring environmental noise levels. Data was collected for one day on weekdays and weekends with three take times at three sampling points. Noise level analysis is carried out using frequency distribution. The next data analysis is to look for the equivalent noise level or LAeq. The noise level points varied between 71,6 dBA-84,02 dBA. The traffic volume reached a peak at 853. The p-value was 0,72 which was above 0,05. The regression test was Y=0,0048x+72,904, and R2 showed 0,15 points, which means that 15% of the noise level was affected by traffic volume. In conclusion, the average noise level at Gatot Subroto Axis Road exceeded the quality standards set according to the Decree of the Minister of State for the Environment No. 48 of 1996, which is 55 dB(A). Despite no significant difference in noise levels on weekdays and weekends based on the t-test, the noise level is affected by traffic volume. Noise from motorized vehicles has quite a big impact on the tranquility of areas that directly intersect with the highway. he limitation of this research is the limited amount of data due to the small number of research points and the insufficient number of days, so further research is needed

Response of shallow geothermal energy pile from laboratory model tests

In shallow geothermal energy pile systems, the thermal loads from the pile, transferred and stored in the soil will cause thermally induced settlement. This factor must be considered in the geotechnical design process to avoid unexpected hazards. Series of laboratory model tests were carried out to study the behaviour of energy piles installed in kaolin soil, subjected to thermal loads and a combination of axial and thermal loads (henceforth known as thermo-axial loads). Six tests which included two thermal load tests (35°C and 40°C) and four thermo-axial load tests (100 N and 200 N, combined with 35°C and 40°C thermal loads) were conducted. To simulate the behaviour of geothermal energy piles during its operation, the thermo-axial tests were carried out by applying an axial load to the model pile head, and a subsequent application of thermal load. The model soil was compacted at 90% maximum dry density and had an undrained shear strength of 37 kPa, thus classified as having a firm soil consistency. The behaviour of model pile, having the ultimate load capacity of 460 N, was monitored using a linear variable displacement transducer, load cell and wire thermocouple, to measure the pile head settlement, applied axial load and model pile temperature. The acquired data from this study was used to define the thermo-axial response characteristics of the energy pile model. In this study, the limiting settlement was defined as 10% of the model pile diameter. For thermal load tests, higher thermal loads induced higher values of thermal settlement. At 40°C thermal load an irreversible settlement was observed after the heating and cooling cycle was applied to the model pile. Meanwhile, the pile response to thermo-axial loads were attributed to soil consistency and the magnitude of both the axial and thermal loads applied to the pile. The higher the thermoaxial loads, the higher the settlements occurred. A slight hazard on the model pile was detected, since the settlement occurred was greater than the limiting value when the pile was loaded with thermo-axial loads of 40°C and 200 N. It is therefore recommended that the global factor of safety to be applied for energy pile installed in firm soil should be more than 2.3 to prevent any hazard to occur in the future, should the pile also be subjected to thermal load of 40°C or greater

Effects of Teacher Efficacy and Emotional Intelligence on Class Management Moderated Transformational Leadership Styles

This study is to examine the effect of teacher efficacy (TE), emotional intelligence (EI), on classroom management (CM) moderated by transformational leadership style (TLS) in Randudongkal District Private Vocational Schools. The research population was the Randudongkal Islamic Vocational Teachers, 7 Randudongkal Muhammadiyah Vocational Teachers, Mejagong TIO Vocational Teachers, Randudongkal 3 Vocational School Teachers in Randudongkal District, amounting to 185 people. Research data is primary data obtained directly from respondents with a questionnaire. Data analysis techniques using multiple linear regression using SPSS for Windows program. The results of the study were: teacher efficacy had no effect on classroom management, emotional intelligence had a positive and significant effect on classroom management, transformational leadership style had a positive and significant effect on classroom management. &nbsp

Penanaman Karakter Santri Taman Pendidikan Al-Qur'an Al-Umm Kroya

This article describes the character planting of the students of the Al-Qur'an Education Park or TPA. Al-Qur'an Education Park is an educational institution where children can learn and play under the guidance of a teacher or cleric. Character formation is a form of government efforts to form a generation that has character. In realizing this, support from all parties is needed, including TPA. Character education is an effort to create a generation that has ethics, morals and morality. This type of research is a qualitative descriptive study conducted at TPA al-umm. Data collection techniques using interviews, observation and documentation. The results of the analysis of this study are that the teacher carries out several stages in inculcating the character of the santri alumm, the stages of this activity are the first religious moderation lecture activities, the second provides a good example that can be followed by the santi. The third is providing religious teaching that will add insight to the students in the TPA. This activity aims to shape children's character better than before. The method of implementing community service activities is to participate in the field directly. The result of this community service activity is the creation of a generation that has good morals and a broad understanding of religion