scholarly journals Improvement of Auto Checking Hardness Machine using Several Material Series of Aluminum Structural Frame: Case Study on Mitutoyo HR-522 Hardness Tester

2020 ◽  
Vol 27 ◽  
pp. 117-124
Author(s):  
Bernardus Plasenta Previo Caesar ◽  
Iwan Istanto ◽  
Pandu Sandi Pratama ◽  
Joung Hyung Cho ◽  
Aditya Rio Prabowo
Otopro ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. 34
Author(s):  
Sabdha Purna Yudha

The use of sand as a mold in the casting process is very common. In this study, Balikpapan sand used as casting sand then analyzed its effect on hardness and fluidity of the Al-Si alloy. The research method used in this research is quantitative research methods using pre-experimental design, especially the one-shot case study model. The final results of this study will be obtained (1) the value of metal hardness from casting using the Micro Vickers Hardness Tester with a Hardness Vickers (HV) scale, (2) fluidity testing is carried out using the Birmingham method in order to determine the length of the cast metal flow (mm) on the final result of casting.


Author(s):  
Mohammad Almashaqbeh ◽  
Khaled El-Rayes

Prefabricated modules in modular construction projects can have a wide range of finishing levels that range from partially completed with only structural frame to fully completed with all structural, wall, mechanical, electrical, finishing and furnishing components. A higher module finishing level increases the offsite fabrication and transportation cost and decreases onsite assembly cost and duration while a lower finishing level produces the opposite results. This paper presents an optimization model that enables construction planners to identify an optimal finishing level for prefabricated modules in order to minimize the total cost of modular construction projects that includes all offsite fabrication, transportation, and onsite assembly costs. A case study of a modular construction project for a healthcare facility was analyzed to illustrate the use of the model and evaluate its performance. The results of this analysis highlight the original capabilities of the model in minimizing the total cost of modular construction projects.


2013 ◽  
Vol 353-356 ◽  
pp. 2799-2802
Author(s):  
Gwang Hee Kim ◽  
Hyun Woo Joh ◽  
Young Do Lee ◽  
Yoon Seok Shin

With increasing land prices and a lack of space in urban areas, urban construction sites are requiring deeper and larger excavations. For this reason, excavation is becoming more important. With deeper excavation, the retaining wall system needs to be adjusted, and a support system for retaining walls needs to be established so that the construction can resist the soil pressure. This can have potential problems depending on construction costs, the duration of construction, and the quality of structural frame. Therefore, the purpose of this study was to compare the conventional retaining wall system with the use of a Reinforcement Self-Supported Retaining Wall (RSW). This study revealed that the construction costs of RSW are 4 percent lower than those for the conventional retaining wall system.


2016 ◽  
Vol 17 (3) ◽  
pp. 303-321 ◽  
Author(s):  
Alison Phipps

Whose personal is more political? This article explores the role of experience in contemporary feminist politics, arguing that it operates as a form of capital within abstracted and decontextualised debates which entrench existing power relations. In a neoliberal context in which the personal and emotional is commodified, powerful groups mobilise traumatic narratives to gain political advantage. Through case study analysis this article shows how privileged feminists, speaking for others and sometimes for themselves, use experience to generate emotion and justify particular agendas, silencing critics who are often from more marginalised social positions. The use of the experiential as capital both reflects and perpetuates the neoliberal invisibilisation of structural dynamics: it situates all experiences as equal, and in the process fortifies existing inequalities. This competitive discursive field is polarising, and creates selective empathies through which we tend to discredit others’ realities instead of engaging with their politics. However, I am not arguing for a renunciation of the politics of experience: instead, I ask that we resist its commodification and respect varied narratives while situating them in a structural frame.


2014 ◽  
Vol 38 (01) ◽  
pp. 102-129
Author(s):  
ALBERTO MARTÍN ÁLVAREZ ◽  
EUDALD CORTINA ORERO

AbstractUsing interviews with former militants and previously unpublished documents, this article traces the genesis and internal dynamics of the Ejército Revolucionario del Pueblo (People's Revolutionary Army, ERP) in El Salvador during the early years of its existence (1970–6). This period was marked by the inability of the ERP to maintain internal coherence or any consensus on revolutionary strategy, which led to a series of splits and internal fights over control of the organisation. The evidence marshalled in this case study sheds new light on the origins of the armed Salvadorean Left and thus contributes to a wider understanding of the processes of formation and internal dynamics of armed left-wing groups that emerged from the 1960s onwards in Latin America.


2020 ◽  
Vol 43 ◽  
Author(s):  
Michael Lifshitz ◽  
T. M. Luhrmann

Abstract Culture shapes our basic sensory experience of the world. This is particularly striking in the study of religion and psychosis, where we and others have shown that cultural context determines both the structure and content of hallucination-like events. The cultural shaping of hallucinations may provide a rich case-study for linking cultural learning with emerging prediction-based models of perception.


2019 ◽  
Vol 42 ◽  
Author(s):  
Daniel J. Povinelli ◽  
Gabrielle C. Glorioso ◽  
Shannon L. Kuznar ◽  
Mateja Pavlic

Abstract Hoerl and McCormack demonstrate that although animals possess a sophisticated temporal updating system, there is no evidence that they also possess a temporal reasoning system. This important case study is directly related to the broader claim that although animals are manifestly capable of first-order (perceptually-based) relational reasoning, they lack the capacity for higher-order, role-based relational reasoning. We argue this distinction applies to all domains of cognition.


2019 ◽  
Vol 42 ◽  
Author(s):  
Penny Van Bergen ◽  
John Sutton

Abstract Sociocultural developmental psychology can drive new directions in gadgetry science. We use autobiographical memory, a compound capacity incorporating episodic memory, as a case study. Autobiographical memory emerges late in development, supported by interactions with parents. Intervention research highlights the causal influence of these interactions, whereas cross-cultural research demonstrates culturally determined diversity. Different patterns of inheritance are discussed.


Author(s):  
D. L. Callahan

Modern polishing, precision machining and microindentation techniques allow the processing and mechanical characterization of ceramics at nanometric scales and within entirely plastic deformation regimes. The mechanical response of most ceramics to such highly constrained contact is not predictable from macroscopic properties and the microstructural deformation patterns have proven difficult to characterize by the application of any individual technique. In this study, TEM techniques of contrast analysis and CBED are combined with stereographic analysis to construct a three-dimensional microstructure deformation map of the surface of a perfectly plastic microindentation on macroscopically brittle aluminum nitride.The bright field image in Figure 1 shows a lg Vickers microindentation contained within a single AlN grain far from any boundaries. High densities of dislocations are evident, particularly near facet edges but are not individually resolvable. The prominent bend contours also indicate the severity of plastic deformation. Figure 2 is a selected area diffraction pattern covering the entire indentation area.


Author(s):  
K. Cowden ◽  
B. Giammara ◽  
T. Devine ◽  
J. Hanker

Plaster of Paris (calcium sulfate hemihydrate, CaSO4. ½ H2O) has been used as a biomedical implant material since 1892. One of the primary limiting factors of these implants is their mechanical properties. These materials have low compressive and tensile strengths when compared to normal bone. These are important limiting factors where large biomechanical forces exist. Previous work has suggested that sterilization techniques could affect the implant’s strength. A study of plaster of Paris implant mechanical and physical properties to find optimum sterilization techniques therefore, could lead to a significant increase in their application and promise for future use as hard tissue prosthetic materials.USG Medical Grade Calcium Sulfate Hemihydrate Types A, A-1 and B, were sterilized by dry heat and by gamma radiation. Types A and B were additionally sterilized with and without the setting agent potassium sulfate (K2SO4). The plaster mixtures were then moistened with a minimum amount of water and formed into disks (.339 in. diameter x .053 in. deep) in polyethylene molds with a microspatula. After drying, the disks were fractured with a Stokes Hardness Tester. The compressive strengths of the disks were obtained directly from the hardness tester. Values for the maximum tensile strengths σo were then calculated: where (P = applied compression, D = disk diameter, and t = disk thickness). Plaster disks (types A and B) that contained no setting agent showed a significant loss in strength with either dry heat or gamma radiation sterilization. Those that contained potassium sulfate (K2SO4) did not show a significant loss in strength with either sterilization technique. In all comparisons (with and without K2SO4 and with either dry heat or gamma radiation sterilization) the type B plaster had higher compressive and tensile strengths than that of the type A plaster. The type A-1 plaster however, which is specially modified for accelerated setting, was comparable to that of type B with K2SO4 in both compressive and tensile strength (Table 1).


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