Thermomechanical behavior of a directionally solidified nickel-base superalloys in the aged state

Understanding the effects of aged microstructures on the thermomechanical fatigue (TMF) properties of nickel-base (Ni-base) superalloys remains unclear. Few experimental results are currently available in this area, and of the limited results available, some promote aged microstructures as beneficial, while others as detri- mental. The importance of these aged structures arises from the fact that when components used in the hot sections of gas turbine engines remain in service for ex- tended periods of time, the local temperature and stress provides the catalyst for the evolution of the microstructure. An experimental assessment of a negative misfit directionally solidified (DS) Ni- base superalloy was undertaken to characterize the aging kinetics and understand the influence of the TMF cycle temperature extremum, temperature-load phasing, mean strain, creep-fatigue, orientation effects, and microstructure on TMF fatigue crack initiation. To determine the effects of aging on the TMF response, the as-heat- treated alloy was artificially aged to three unique microstructures identified in the aging kinetics study. The experiments revealed that not all aged microstructures are detrimental to the fatigue life behavior. Specifically, when the γ′ precipitates age in a manner to align themselves parallel to the axis of the applied stress, an increase in the fatigue life over that of the as-heat-treated microstructure is observed for out-of-phase TMF with dwells. To extend the experimental understanding of the aged microstructures into ser- vice component design and life analysis, a temperature-dependent crystal viscoplas- ticity (CVP) constitutive model is developed to capture the sensitivity of the aged microstructure through embedding additional variables associated with the current state of the γ′ particles. As a result of the adaptations, the CVP model has the ability to describe the long-term aging effects of directional coarsening relevant to the analysis industrial gas turbine hot section components.Ph.D

The relation of self-compassion and self-esteem with emotional regulation and control

Cilj ovog istraživanja je utvrditi odnos samosuosjećanja i samopoštovanja sa emocionalnom regulacijom i kontrolom i demografskim varijablama, te utvrditi postoje li razlike u samosuosjećanju i emocionalnoj regulaciji i kontroli s obzirom na vrstu samopoštovanja. Ukupno 1648 sudionika ispunjavalo je upitnike koji ispituju samopoštovanje (Tafarodi i Swann, 1995), samosuosjećanje (Neff, 2003) i emocionalnu regulaciju i kontrolu (Takšić, 2003). Dobivene su pozitivne korelacije samosuosjećanja s dobi, samopoštovanja i samosuosjećanja sa socioekonomskim statusom, te emocionalne regulacije i kontrole sa samosuosjećanjem i samopoštovanjem. Rezultati regresijske analize pokazuju da su socioekonomski status i emocionalna regulacija i kontrola prediktori samopoštovanja, dok su prediktori samosuosjećanja dob, socioekonomski status i emocionalna regulacija i kontrola. Jednostavna analiza varijance pokazala je značajne razlike između tri skupine sudionika podijeljenih po vrsti samopoštovanja u izraženosti samosuosjećanja i emocionalne regulacije i kontrole, pri čemu sudionici sa stabilnim niskim samopoštovanjem doživljavaju najmanje suosjećanje i imaju najmanje emocionalne regulacije i kontrole, sudionici sa stabilnim visokim samopoštovanjem doživljavaju najviše suosjećanje i imaju najviše emocionalne regulacije i kontrole, a sudionici sa paradoksalnim samopoštovanjem se smještaju između te dvije grupe.The aim of this study was to determine the relationship of self-compassion and self-esteem with emotional regulation and control and demographic variables as well as determine if there are differences in self-compassion and emotional regulation and control for different types of self-esteem. A total of 1648 participants responded to questionnaires that examined self-esteem (Tafarodi i Swann, 1995), self-compassion (Neff, 2003) and emotional regulation and control Takšić, 2003). We obtained positive correlations of self-compassion with age, self-esteem and self-compassion with social class and emotional regulation and control with self-esteem and self-compassion. Results of regression analyses showed that social class and emotional regulation and control predict the construct of selfesteem, while age, social class and emotional regulation and control predict the construct of selfcompassion. One-way analysis of variance showed significant differences between three groups of participants separated according to the type of self-esteem in self-compassion and emotional regulation and control wherein participants with stabile low self-esteem experienced the least selfcompassion and have the least emotional regulation and control, participants with stabile high selfesteem experienced the most self-compassion and have the most emotional regulation and control and participants with paradoxical self-esteem are placed between the other two groups

Gatekeeping: A Counselor Educator’s Responsibility to the Counseling Profession and Community

Counseling is one of the few professions practiced in private with vulnerable individuals. Because of this, counselors must be held to high training standards and be deemed competent prior to being allowed to practice independently. The responsibility for ensuring future counselors’ competence rests with counselor educators and clinical supervisors via a process known as gatekeeping. This paper highlights the importance of gatekeeping in the counseling profession and describes models of remediation for supervisors and educators navigating this complex process. Utilizing a case study, the authors demonstrate the protective function gatekeeping serves society by applying a gatekeeping decision-making model. Finally, recommendations are provided to increase adherence to and facilitate implementation of gatekeeping responsibilities by counselor educators and supervisors

PHARMACOKINETIC PREDICTIONS AND MOLECULAR DYNAMIC ANALYSIS OF TERPENOID AND FLAVONOID COMPOUNDS FROM MIANA LEAVES (PLECTRANTHUS SCUTELLARIOIDES (L.) R. BR.) AS AN ANTIMALARIAL CANDIDATES ON PLASMEPSIN II RECEPTOR

Objective: This study aims to find antimalarial candidates from 32 terpenoids and three flavonoid compounds found in miana leaves in silico using plasmepsin protein as a receptor through docking simulations, molecular dynamics simulations, and pharmacokinetic predictions. Methods: The research was conducted in silico through molecular docking simulation, molecular dynamic simulations, analysis of potential compounds using Lipinski’s rule, and prediction of ADMET based on ligands. Results: The results showed isophytol had the best interaction with the plasmepsin II based on the low free binding energy (FBE) and led to hydrogen bonding with the plasmepsin II crucial amino acid, Asp34. Isophytol has the best result in molecular dynamic simulation. Based on pharmacokinetics predictions, toxicity, and Lipinski’s rule of five, most tested compounds, including isophytol, meet the criteria as a promising drug. Conclusion: Isophytol from miana leaves with plasmepsin II protein has the best and most stable interaction based on the results of molecular dynamic simulation, so this compound was a candidate for antimalarial drugs

Additive manufacturing enabling W-SiC and W-ZrB2-SiC heterogeneous materials

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Location-Specific Microstructure and the Effect of Heat Treatment on Electron-Beam Melted Ni-Based Superalloy LSHR

Examine set-to-set variability with 4 build sets with the same layout Establish the effect of solutioning heat treatments (HT) on as-fabricated grain structure and microstructure (gamma)-solvus= 1156 C (1) As-fabricated (2) 2 hour subsolvus HT(-15 C) + conventional 2-step aging (3, 4, 5) 0.5 hour, 2 hours, 4 hours supersolvus HT (+18 C) + 2 step aging Gain insight into location-specific microstructure to correlate later to mechanical properties (tensile, creep, LCF behavior

REVIEW ARTIKEL : TANAMAN YANG MEMILIKI AKTIVITAS ANTI-ULSER DI ASIA

Introduction : Herbal medicines have high potential in treating various diseases including gastric ulcers because they are considered safer and more comfortable. Ulcers or gastric ulcers are disorders of the stomach due to an imbalance of aggressive factors (gastric acid secretion, pepsin, and Helicobacter pylori infection) with defensive factors (prostaglandins, mucus, bicarbonate, mucosal blood flow, and intrinsic epithelial cells). Methods : The method used is a literature review study conducted by searching for keywords such as peptic ulcer disease, herbal plants, anti-stomach ulcers, and others in databases such as PubMed and Google Scholar. Results : From the literature review, 29 medicinal plants in Asia have a potential anti-ulcer activity that can prevent and help treat gastric ulcers. The table of medicinal plants is arranged based on the phytochemical analysis, the part used, and the country where the plant originates. Conclusion : Plants that have the potential to prevent and help heal gastric ulcers that are spread in Asia include phytochemicals containing flavonoids, tannins, polyphenols, alkaloids, glycosides, terpenoids, saponins with various mechanisms, namely gastroprotective, antioxidant, anti-inflammatory, anti-secretory, anti-Helicobacter. pylori, and astringents.Pendahuluan: Obat-obatan herbal dapat berpotensi tinggi dalam menangani berbagai penyakit termasuk tukak lambung karena dinilai lebih aman dan nyaman. Tukak atau ulser lambung merupakan gangguan pada lambung akibat ketidakseimbangan faktor agresif (sekresi asam lambung, pepsin, dan infeksi Helicobacter pylori) dengan faktor defensif (prostaglandin, mukus, bikarbonat, aliran darah mukosa, dan sel epitel intrisnik). Metode: Metode yang digunakan yaitu studi tinjauan pustaka yang dilakukan dengan mencari kata kunci seperti peptic ulcer disease, tanaman herbal, anti-tukak lambung dan lain-lain pada basis data berupa PubMed dan Google Scholar. Hasil: Dari hasil tinjauan pustaka, diperoleh 29 tanaman obat di Asia dengan potensi aktivitas anti-ulser yang dapat mencegah dan membantu mengobati tukak lambung. Tabel tanaman obat disusun berdasarkan analisis fitokimia, bagian yang digunakan, serta negara tempat tanaman berasal. Kesimpulan: Tanaman yang berpotensi dalam mencegah dan membantu menyembuhkan tukak lambung yang tersebar di Asia diantaranya memiliki kandungan fitokimia flavonoid, tanin, polifenol, alkaloid, glikosida, terpenoid, saponin dengan berbagai mekanisme yaitu gastroprotektif, antioksidan, antiinflamasi, anti-sekretori, anti-Helicobacter pylori, dan astringen

Porosity detection in electron beam-melted Ti-6Al-4V using high-resolution neutron imaging and grating-based interferometry

© 2017, Springer International Publishing Switzerland. A high-resolution neutron tomography system and a grating-based interferometer are used to explore electron beam-melted titanium test objects. The high-resolution neutron tomography system (attenuation-based imaging) has a pixel size of 6.4 µm, appropriate for detecting voids near 25 µm over a (1.5 cm)3 volume. The neutron interferometer provides dark-field (small-angle scattering) images with a pixel size of 30 µm. Moreover, the interferometer can be tuned to a scattering length, in this case, 1.97 µm, with a field-of-view of (6 cm)3. The combination of high-resolution imaging with grating-based interferometry provides a way for nondestructive testing of defective titanium samples. A chimney-like pore structure was discovered in the attenuation and dark-field images along one face of an electron beam-melted (EBM) Ti-6Al-4V cube. Tomographic reconstructions of the titanium samples are utilized as a source for a binary volume and for skeletonization of the pores. The dark-field volume shows features with dimensions near and smaller than the interferometer auto-correlation scattering length

Microstructure, mechanical properties and cracking behaviour in a gamma'-precipitation strengthened nickel-base superalloy fabricated by electron beam melting

The influences of EBM processing and post-processing on microstructure, mechanical properties and cracking behaviour in a γ′ precipitation-strengthened nickel-base superalloy DZ125 are critically assessed. Results show that a solution treating and ageing (STA) is required to obtain γ′ precipitates with a cuboidal shape. The columnar grain width was found to gradually increase from the bottom to the top of the as-EBM sample having a total build height of 80 mm, whereas there was little gradient in γ′ size. The presence of EBM induced intergranular cracks can be closed by hot isostatic pressing (HIP), however reappearance of intergranular cracks with a much wider crack opening width was observed after STA treatment. EBM induced cracks are classified as liquid-state cracking, as the classic dendritic morphology were found on the cracked surfaces. The post-processing induced cracks can be attributed to the effect of γ′ dissolution and re-precipitation of fine γ′ during the cooling stage of solution treatment. The results suggest that HIP is not an effective approach in healing liquid-state cracks in EBM fabricated γ′ precipitation-strengthened superalloys