ANALISIS PENGARUH VARIASI MATERIAL CORE TERHADAP KUALITAS NIPPLE

2020 ◽  
Vol 8 (2) ◽  
pp. 82-88
Author(s):  
Moh Rofi Julian ◽  
Yopi Handoyo

This study aims to determine the effect of variations in core material made of iron and resin sand on the Nepel Brass smelter on hardness, surface results of castings, shrinkage, density apparent, time, and cost. To find out which core material is more efficient for use in large quantities. The product material used is Brass in the form of Hose Nipple with a size of 1/5 x 5/8 inch. The average specimen weight in this study was 8.33 gr. From the research conducted, the differences were found, namely the hardness of the smelting process with the core material of iron castings and resin sand is 37.14 BH 5 / 250-25 and 30.94 BH 5/250-25. Material defects found are in iron castings specimens, namely rough surface defects, pinhole, scrabs, gas holes and air voids with 19 points of defect points and an area of ​​78 mm or 10.57% of the inside area of ​​the specimen. Likewise with resin sand-coated specimens experiencing defects of Coarse Surface, Needle Hole, Scrabs, Gas Hole, Air Cavity and sand inclusion / erosion hardness, with large numbers almost covering all parts of the specimen or 95.1%. For shrinkage, cast specimens with iron castings are smaller at 0.35% and resin-coated specimens of 0.40%. For porosity defects, iron castings in the specimens were 8.33 and 8.40 in the core of the resin sand castings. The higher the true density, the more dense the material is. The production time is 555 seconds (9 minutes 15 seconds) from the smelting process of specimens with the core of resin sand castings which is for 829 seconds (13 minutes 49 seconds). Whereas for the process of releasing specimens from molds, products with resin sand castings are faster at 14 seconds, while for specimens with iron castings core is 28 seconds. The cost required to make specimens with iron cast core is Rp. 4,718,500, the cost is cheaper than the manufacture of specimens with core resin sand castings that require capital of Rp. 4,999,000.

2015 ◽  
Vol 12 (1) ◽  
pp. 27-30
Author(s):  
Jozef Pilc ◽  
Mário Drbúl ◽  
Dana Stančeková ◽  
Daniel Varga ◽  
Juraj Martinček ◽  
...  

Abstract Increased use of forging tools in mass production causes their increased wear and creates pressure to design more efficient renovation process. Renovation is complicated because of the identification of cracks expanding from the surface to the core material. Given that the production of forging tools is expensive, caused by the cost of tool steels and the thermo-chemical treatment, it is important to design forging tool with its easy renovation in mind. It is important to choose the right renovation technology, which will be able to restore the instrument to its original state while maintaining financial rentability. Choosing the right technology is difficult because of nitrided and heat-treated surface for high hardness and wear resistance. Article discusses the use of non-destructive method of detecting cracks taking into account the size of the cracks formed during working process.


Proceedings ◽  
2020 ◽  
Vol 39 (1) ◽  
pp. 13
Author(s):  
Mezeix ◽  
Wongtimnoi

Sandwich structures are widely used in aeronautics both for primary and secondary structures such as landing gear doors, flaps or floors. Multi-cores materials sandwich structures presents many advantages. By adding layers with another materials that the core one, extra properties can be obtained as heat or impact protection. Manufacturing quality must be controlled and therefore bonding needs to be inspected. In this paper bonding defects between multi-layers of sandwich specimen are inspected through Non Destructive Tests. Due to its large use in industry, ultrasonic phase array is used to detect manufacturing bonding defects. Three different type of multi-cores materials specimen are investigated. Results show that due to the high PVC foam porosity, defects cannot be detected both between composite skins and foam and between foam and core material.


Author(s):  
Robin Markwica

In coercive diplomacy, states threaten military action to persuade opponents to change their behavior. The goal is to achieve a target’s compliance without incurring the cost in blood and treasure of military intervention. Coercers typically employ this strategy toward weaker actors, but targets often refuse to submit and the parties enter into war. To explain these puzzling failures of coercive diplomacy, existing accounts generally refer to coercers’ perceived lack of resolve or targets’ social norms and identities. What these approaches either neglect or do not examine systematically is the role that emotions play in these encounters. The present book contends that target leaders’ affective experience can shape their decision-making in significant ways. Drawing on research in psychology and sociology, the study introduces an additional, emotion-based action model besides the traditional logics of consequences and appropriateness. This logic of affect, or emotional choice theory, posits that target leaders’ choice behavior is influenced by the dynamic interplay between their norms, identities, and five key emotions, namely fear, anger, hope, pride, and humiliation. The core of the action model consists of a series of propositions that specify the emotional conditions under which target leaders are likely to accept or reject a coercer’s demands. The book applies the logic of affect to Nikita Khrushchev’s decision-making during the Cuban missile crisis in 1962 and Saddam Hussein’s choice behavior in the Gulf conflict in 1990–91, offering a novel explanation for why coercive diplomacy succeeded in one case but not in the other.


2021 ◽  
Vol 13 (2) ◽  
pp. 637
Author(s):  
Tomas Astrauskas ◽  
Tomas Januševičius ◽  
Raimondas Grubliauskas

Studies on recycled materials emerged during recent years. This paper investigates samples’ sound absorption properties for panels fabricated of a mixture of paper sludge (PS) and clay mixture. PS was the core material. The sound absorption was measured. We also consider the influence of an air gap between panels and rigid backing. Different air gaps (50, 100, 150, 200 mm) simulate existing acoustic panel systems. Finally, the PS and clay composite panel sound absorption coefficients are compared to those for a typical commercial absorptive ceiling panel. The average sound absorption coefficient of PS-clay composite panels (αavg. in the frequency range from 250 to 1600 Hz) was up to 0.55. The resulting average sound absorption coefficient of panels made of recycled (but unfinished) materials is even somewhat higher than for the finished commercial (finished) acoustic panel (αavg. = 0.51).


Catalysts ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 72
Author(s):  
Christian Zambrzycki ◽  
Runbang Shao ◽  
Archismita Misra ◽  
Carsten Streb ◽  
Ulrich Herr ◽  
...  

Core-shell materials are promising functional materials for fundamental research and industrial application, as their properties can be adapted for specific applications. In particular, particles featuring iron or iron oxide as core material are relevant since they combine magnetic and catalytic properties. The addition of an SiO2 shell around the core particles introduces additional design aspects, such as a pore structure and surface functionalization. Herein, we describe the synthesis and application of iron-based core-shell nanoparticles for two different fields of research that is heterogeneous catalysis and water purification. The iron-based core shell materials were characterized by transmission electron microscopy, as well as N2-physisorption, X-ray diffraction, and vibrating-sample magnetometer measurements in order to correlate their properties with the performance in the target applications. Investigations of these materials in CO2 hydrogenation and water purification show their versatility and applicability in different fields of research and application, after suitable individual functionalization of the core-shell precursor. For design and application of magnetically separable particles, the SiO2 shell is surface-functionalized with an ionic liquid in order to bind water pollutants selectively. The core requires no functionalization, as it provides suitable magnetic properties in the as-made state. For catalytic application in synthesis gas reactions, the SiO2-stabilized core nanoparticles are reductively functionalized to provide the catalytically active metallic iron sites. Therefore, Fe@SiO2 core-shell nanostructures are shown to provide platform materials for various fields of application, after a specific functionalization.


CrystEngComm ◽  
2020 ◽  
Vol 22 (46) ◽  
pp. 8036-8044
Author(s):  
Jannis Wehmeier ◽  
Markus Haase

is an interesting shell material for β-NaREF4 particles of the lighter lanthanides (RE = Ce, Pr, Nd), as variation of its strontium content x allows to vary its lattice parameters and match those of the core material.


2010 ◽  
Vol 24 (15n16) ◽  
pp. 3124-3130 ◽  
Author(s):  
HUI CONG LIU ◽  
XIU QING XU ◽  
WEI PING LI ◽  
YAN HONG GUO ◽  
LI-QUN ZHU

The shell material of microcapsules has an important effect on the electrolytic co-deposition behavior, the release of core material and the surface performance of composite coating. This paper discussed the tensile property and the stability of three shell materials including polyvinyl alcohol (PVA), gelatin and methyl cellulose (MC). It is found that these three shell materials have good mechanical strength and flexibility which are favorable to electrolytic co-deposition and stability of microcapsules in composite coating and that MC has well permeability and porosity which has a positive effect on the release of the core material in composite coating. Moreover, the study of the thermal properties and water vapor permeability of the three shell materials showed that their permeability improved with increase of temperature and humidity. In addition, the composite copper coating containing microcapsules with PVA, gelatin or MC as shell material was prepared respectively.


Author(s):  
Cesim Atas ◽  
Alper Basmaci

AbstractThe damage behavior of the potting materials around a pinhole, being used in the mechanical joints of sandwich composites, is investigated experimentally. The sandwich composite panels used in the tests were manufactured by the vacuum-assisted resin infusion technique. Each of the top and bottom face sheets of the panels consisted of two woven E-glass/epoxy layers. As the core material, PVC foam (AIREX


2012 ◽  
Vol 509 ◽  
pp. 209-214
Author(s):  
Shao Peng Wu ◽  
Pan Pan ◽  
Ming Yu Chen

With the widespread application of asphalt mixture, current demand from transportation managers for construction and maintenance of their pavement network consumes large numbers of aggregates. If agencies excessively favor to some certain kinds of excellent aggregates, the cost of construction could be considerably expensive. The major objective of this study is to determine the feasibility of utilizing dacite in asphalt mixtures. By means of Marshall, freeze-thaw, rutting and three-point bending tests, the performances of dacite and basalt asphalt mixture are compared. The results of the testing illustrate that dacite asphalt mixture is more susceptible to gradation and asphalt content than basalt asphalt mixture. Meanwhile it is showed that the performances of dacite asphalt mixture can be improved greatly with the involvement of additives including active mineral powder and cement. Furthermore, it is validated that dacite can be used as alternative aggregate in asphalt mixture.


2007 ◽  
Vol 342-343 ◽  
pp. 505-508
Author(s):  
Sung Won Kim ◽  
Yun Sik Nam ◽  
Yeon Jin Min ◽  
Jong Ho Kim ◽  
Kwang Meyong Kim ◽  
...  

Stability and disintegration of natural polyelectrolyte complex microspheres for protein drugs delivery have been extensively investigated because of their great influence on the drug release patterns. In this study, we tested stability of microspheres with alginate (Alg) core layered by either chitosan (Chi) or glycol chitosan (GChi) by examining release profiles of fluorophorelabeled bovine serum albumin (BSA) and lysozyme (Lys) from the microspheres. While GChi shell was disintegrated quickly, Chi-shell microspheres showed good stability in PBS. Disintegration of the coated layer induced the core material instable. The results indicated that while the charges of the shell material provided additional diffusion barrier against the protein release, the key factor to hold the proteins inside the microspheres was the integrity of the outer coating layer.


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