Description of the Learning Difficulties on Chapter Parabolic Motion and the Factors Affecting in Physics Pre-Service Teacher

The problem of student learning difficulties and the factors causing it are very important to know. The first step that can be taken is to use a diagnostic test as a reference indicator in identifying student learning difficulties. The purpose of this study was to determine the difficulties in learning parabolic motion and its causal factors experienced by students of the 2018 Physics Education Department. This type of research is descriptive. The subjects of this study were 19 students of the 2018 Cenderawasih University in the Physics Education Department. Data collection techniques used are test, interview, and documentation. The results of the overall assessment of the diagnostic test showed that 19 students had not yet completed achieving the learning objectives in understanding the parabolic motion sub-material because the highest score obtained by one of the students was 53, while the minimum completeness reached a score of 56. These difficulties are influenced by internal factors, namely body defects, fatigue, attention, readiness, habits, how to receive lessons, boredom; and external factors, namely the lecturer’s teaching methods, discipline, building conditions, forms of community life, and weather conditions.

Assessment of Destructive Impact of Different Factors on Concrete Structures Durability

The durability of concrete structure members is dependent on several factors that should be analyzed at each stage of the construction process. Omitting any of these factors might lead to the augmentation of harmful interactions and, as an effect, to safety hazards and the degradation of a structure or its parts. The article, based on several years of studies on exploited concrete structures, presents the effects of an incorrect analysis of selected factors resulting in the occurrence of faults significantly influencing the possibility of safe use of the objects. The described cases include, but are not limited to, the consequences of an improper assessment of building conditions after a biogas explosion in a fermentation chamber, the effect of a wood dust explosion, fire temperature and firefighting action on the prestressed girders, the stages of degradation of bearing structures supporting gas tanks exploited in an aggressive environment, and the consequences of omitting the temperature load in relation to the upper surface of a plate covering the fire pond. In each case, methods of restoration of the damaged elements were proposed, and their application to engineering practice was described. The practical aspects of the conducted research and implemented interventions were indicated.

Design of Male Student Dormitory Medan State University with Appropriate Site Development Concept (Green Architecture)

Student dormitories are the residential neighborhood as student residences during their lectures. The dorms are increasing as students access different regions to study at a university. Medan city has several dorms which one is of Medan State University. This student dormitory is a special dormitory for male students of Medan State University who come from areas in North Sumatra. The condition of the dormitories is considered inadequate as a Student dormitories capacity is less than required. The existing student dormitory facilities are not complete for student dormitory facilities. It is necessary to design the male student dormitory of Medan State University. In this design, the Medan State University male student dormitory requires additional supporting facilities around the student dormitory and good building conditions. The location of the building is in the educational Area on Jalan William Iskandar Pasar V, New Memories, Percut Sei Tuan. The Male Student Dormitories applies green architecture with a basic concept approach to land use which is considered to respect every criterion contained in the land, made as comfortable as possible, responsive to the factors evaluated at the construction site.

Improved Resolution and Cost Performance of Low-Cost MEMS Seismic Sensor through Parallel Acquisition

In earthquake monitoring, an important aspect of the operational effect of earthquake intensity rapid reporting and earthquake early warning networks depends on the density and performance of the deployed seismic sensors. To improve the resolution of seismic sensors as much as possible while keeping costs low, in this article the use of multiple low-cost and low-resolution digital MEMS accelerometers is proposed to increase the resolution through the correlation average method. In addition, a cost-effective MEMS seismic sensor is developed. With ARM and Linux embedded computer technology, this instrument can cyclically store the continuous collected data on a built-in large-capacity SD card for approximately 12 months. With its real-time seismic data processing algorithm, this instrument is able to automatically identify seismic events and calculate ground motion parameters. Moreover, the instrument is easy to install in a variety of ground or building conditions. The results show that the RMS noise of the instrument is reduced from 0.096 cm/s2 with a single MEMS accelerometer to 0.034 cm/s2 in a bandwidth of 0.1–20 Hz by using the correlation average method of eight low-cost MEMS accelerometers. The dynamic range reaches more than 90 dB, the amplitude–frequency response of its input and output within −3 dB is DC −80 Hz, and the linearity is better than 0.47%. In the records from our instrument, earthquakes with magnitudes between M2.2 and M5.1 and distances from the epicenter shorter than 200 km have a relatively high SNR, and are more visible than they were prior to the joint averaging.

INVESTIGATION OF TECHNOLOGICAL PARAMETERS OF THE DEVICE AND REPAIR OF THE BASES OF FLAT ROOFING

In the practice of modern construction, light concretes of low thermal conductivity are used as a thermal insulation layer of enclosing structures. In particular, they are used for insulation of flat roofs of buildings for various purposes. One of their effective methods of thermal insulation is the use of polystyrene concrete of low average density and thermal conductivity directly in building conditions. Studies have established the rational selection of the composition of this type of concrete for the device of a monolithic thermal insulation layer, the resource support of the technological process, including the mechanization of work and qualification requirements for performers. The improvement of organizational and technological solutions of flat roofs based on the choice of rational parameters of technological processes and operations ensures a reduction in the complexity, duration and cost of work on the construction site.

Evaluation of spatter particles, metal vapour jets, and depressions considering influence of laser incident angle on melt pool behaviour

Building of practical parts involves the application of metal-based laser powder bed fusion using a laser beam (PBF-LB/M) owing to its high-precision manufacturing. However, the quality of the built parts obtained via the PBF-LB/M processes varies with the building conditions, and a thorough understanding of the building mechanism has not been achieved owing to the complex and interrelated process parameters involved. The incident angle of the laser beam, which changes on the platform during the laser beam scan owing to the designed three-dimensional data, is among the principal parameters that affects the building aspects. In this study, the melt pool in the singletrack formation during the PBF-LB/M processes was visualised using a high-speed camera, and the influence of the laser incident angle on the ejection characteristics of spatter particles formed around the laser-irradiated area was investigated. Consequently, the spatter particles and metal vapour jet behaviour varied with the laser incident angle. There was a reduction in number of spatter particles owing to the origin of the incident direction being from behind the laser irradiation area. In addition, the laser incident angle also affected the melt pool morphology because of the depression in the melting. Furthermore, the burial depth of the pores varied with the laser incident angle, and is related to the depth of the depression during the melt pool formation.

Penerapan Sistem Pendukung Keputusan Menentukan Ranking Sekolah Unggulan Kabupaten Nias Dengan Menggunakan Metode AHP

One of the computational methods that is currently developing is the Decision Support System method. Decision Support System is part of a computer-based information system including a knowledge-based system that is used to support decision making. In choosing a school, prospective students tend to follow their friends without knowing which school to go to in accordance with educational standards. The Analytical Hierarchy Process (AHP) method was declared feasible because it is faster and more effective, so it can be ascertained that the application of the AHP method can solve problems in the selection of superior schools in Nias Regency. Alternative data consisted of SMAN 1 Gido, SMAN 1 Botomuzoi, SMAN 2 Gunung Sitoli, SMAN 1 Gunungsitoli. Data criteria include Teacher Education, Building Conditions, School Cleanliness, Facilities. Processing of SPK using the AHP method resulted in the school of SMAN 2 Gunung Sitoli having the highest score of 2.68. Web-based system built using PHP with AHP decision support methods and MySQL database.

GREEN: Cool & Care—Research and Development of Greening Measures in Nursing Homes in Austria. Technical and Social Interconnections

According to demographic data, the percentage of elderly people within the population is growing, representing a vulnerable group to the effects of increasing heat, but little attention has been paid to developed adaptation measures. In addition, many older people leave their familiar homes and live in nursing homes. The person-centred care pursues creating spaces of high living quality for these people in nursing homes, to which plants and greenery can contribute. Greening is also considered an effective climate change adaptation measure. To create healthy conditions for this vulnerable group of elderly, both technical and social factors must be considered, and accordingly, a successful solution can only be achieved in an interdisciplinary way. The research and development of the project “Green: Cool & Care” dealt with this outset from a building physics, social, and nursing science perspective, and concepts to integrate greening measures in nursing homes were developed jointly by researchers, planners, staff, volunteers, and residents. For this purpose, measurement campaigns of air quality parameters, individual interviews and focus groups, as well as co-creative workshops were conducted aiming to include the objective building conditions as well as the subjective needs in developing and, in a further step, implementing greening measures.