Pressure welding of continuously cast nodular iron

The objective of this study was to determine the feasibility of using pressure welding as a joining technique for swaged nodular iron. Test pressure welds were produced with swaged continuous cast nodular iron at temperatures between 1750⁰F and 2050⁰F with welding pressures between 15,900 psi and 51,400 psi using an induction coil to heat the weld zone. Pressure welds of greater strength than the as-received nodular iron were produced by swaging the material before welding. The optimum welding parameters were a temperature of 2050⁰F with a welding pressure of 46,700 psi. On the basis of these tests it is concluded that pressure welding of nodular iron is feasible for joining structures in which the deformed zone is not detrimental or can be removed by machining --Abstract, page ii

The ice particles in Saturn’s E ring and measurements of the Cassini Cosmic Dust Analyzer and its High Rate Detector

Abstract. This thesis is a literature review on Saturn’s E ring and the respective results obtained by the Cassini Cosmic Dust Analyzer and its subsystem High Rate Detector during Cassini-Huygens mission to Saturn. The Cassini spacecraft spent 13 years orbiting Saturn while studying the planet, its many satellites and its various rings. One of the most interesting rings to an in-situ instrument is the vast E ring, which originates from the tiny ice-surfaced moon Enceladus. Enceladus’ active southern polar region has massive geysir-like phenomena powered by the moon’s global subsurface ocean. The jets of (dominantly) water vapor and ice grains are launched to such heights that some of the ice particles do not fall back on the moon and form the E ring. The ring is constantly supplied with new material and it has spread to cover an orbital distance of 1 000 000 kilometers, making it the second largest planetary ring in the Solar System. The E ring was previously observed with different imaging techniques, but the Cassini opened new research possibilities for in-situ observations with its various instruments. For this thesis, a major focus is the Cosmic Dust Analyzer (CDA) instrument and its subsystem, the High Rate Detector (HRD). The CDA is an instrument for determining properties, such as mass, velocity and mass spectra, of dust particles that collide with it, while the HRD is used to get data on the number of occurring impacts, ie. number density of particles. These properties allowed scientists to determine, for example, the composition of particles within the E ring and the ring’s spatial density. The CDA and the HRD had a crucial impact all the way to the last years of the mission where it played a key role in exploring the subsurface conditions of Enceladus and its habitability

Neural cell adhesion molecules in rat endocrine tissues and tumor cells: distribution and molecular analysis

The adhesive properties of neural cell adhesion molecules (NCAMs) can be modified by alternative splicing of the primary transcript or posttranslational modifications. In the present study, we describe distinct forms of alternative splicing and posttranslational modification of the extracellular domain of NCAM of various endocrine tissues and derived tumor cells of the rat. Using an antiserum detecting the immunoglobulin-like domains of NCAM as well as a monoclonal antibody recognizing the NCAM-specific polysialic acid (PSA), we observed a similar staining pattern in adrenals, pituitary, and neoplastic endocrine cells. In endocrine tumor cells [pheochromocytoma (PC12), insulinoma (RINA2), and pituitary tumor cells (GH3)], NCAM immunoreactivity was most intense at contact sites between the cells. The immunocytochemical data were substantiated by results of in situ hybridization histochemistry. Specifically, higher levels of NCAM mRNA were detected in the adrenal cortex than in the medulla. In the pituitary, NCAM mRNA was more abundant in the anterior and intermediate lobes than in the neural lobe. The sequence of NCAM mRNAs in endocrine cells was analyzed by polymerase chain reaction and S1 nuclease protection assays. We found that major exons 4-13 of the NCAM mRNA in endocrine tissues and related tumor cell lines were homologous to those in the brain. However, PC12, RINA2, and GH3 tumor cells; normal rat pituitaries; and adrenals contained different amounts of NCAM mRNA with an alternative extra exon, termed VASE (also called pi in mouse) between constitutive exons 7 and 8. In addition, in pituitaries, we detected an alternative exon in splice site a between the constitutive exons 12 and 13, termed a15, with or without an AAG triplett. These sites are thought to be important for the adhesive properties of NCAM. Therefore, these results suggest that modifications of NCAM may be important for adhesive interactions in normal and neoplastic endocrine cells

Evaluating Behavioral Health Service Need for Sexual and Gender Minorities: A Community-Based Qualitative Study

The LGBTQ community experiences mental health challenges, such as anxiety, depression, and substance use disorders, at rates higher than heterosexual and cisgender counterparts. Given these disparities in mental health, it is crucial that the LGBTQ population has access to mental health services. However, LGBTQ individuals face barriers to accessing mental health care due to service affordability, availability, and/or lack of LGBT-inclusivity. A Place to Nourish your Health (APNH), formerly known as AIDS Project New Haven, has historically provided care to those in New Haven who live with HIV and AIDS. APNH is now seeking to re-define itself as an organization by expanding services to support those experiencing stigma related to gender identity, sexual orientation, addiction, and mental health. Thus, to aid APNH in their service expansion to stigmatized populations, we performed a qualitative community needs assessment in the greater New Haven area to inform where APNH’s priorities should lie in their expansion of services. Findings provided insight into the current mental health landscape of New Haven’s LGBTQ community and led to reccomendatios regarding APNH\u27s expanion of behavoral health services.https://elischolar.library.yale.edu/ysph_pbchrr/1024/thumbnail.jp

Leydig cells express neural cell adhesion molecules in vivo and in vitro

The neural cell adhesion molecule (NCAM) polypeptides are expressed by numerous tissues during embryonic development, where they are involved in cell-cell interactions. In the adult, NCAM expression is confined to a few cell types, including neurons and peptide-hormone-producing cells. Here we demonstrate that the Leydig cells of the adult rat, mouse, and hamster testes express NCAM as well. Western blotting showed that an NCAM of approximately 120 kDa was present in the adult testes of all three species investigated. This form was also found in freshly isolated mouse Leydig cells and in Leydig cells after 2 days in culture. After 4 days in culture, mouse Leydig cells expressed additional NCAM isoforms of approximately 140 and 180 kDa, indicating changes in alternative splicing of NCAM primary transcripts. Also, NCAM mRNA of all isoforms, as detected by S1-nuclease protection assays, increased with time in culture. The expression of the cell adhesion molecule NCAM by adult Leydig cells may explain the aggregation of Leydig cells in clusters in rodent testes, which could be a prerequisite for functional coordination of groups of Leydig cells. Furthermore, the presence of this neural and endocrine marker may indicate a closer relationship between Leydig cells and neural and peptide-hormone-producing cells than is considered to exist at the present time

A Study of Ductile Damage and Failure of Pure Copper – Part I: Constitutive Equations and Experiments

This paper presents the results of an experimental study of ductile damage and failure of pure copper. Uniaxial tension tests were performed for specimens with different arrangements of pre-drilled micro-holes representing the simulation models of cylindrical voids. This experimental method has already been applied by a number of researchers in order to investigate the damage of metals under plastic deformation and proved to be useful for studying an evolution of damage in ductile materials in terms of local strains of both representative volume elements (RVE) and meso-elements (i.e., material unit cells with a single void). Two measures are used for the assessment of damage in the deformed material. The first one relates damage to an increase in the void volume. The second measure accounts for the damage associated with a change in the void shape. Both measures were introduced as part of a tensorial theory of damage in Zapara et al. (2008). They are based on experimental studies of damage kinetics in metallic materials under plasticity conditions. In combination with similar data from the literature the obtained results are important for the modeling of metal forming processes with dominating tensile deformation (e.g., deep-drawing, ironing, wire drawing)

A Study of Ductile Damage and Failure of Pure Copper – Part II: Analysis of the Deep Drawing Process of a Cylindrical Shell

The analysis of the stress-strain state and strain induced damage of a cylindrical shell made of copper during the process of deep drawing is presented. The stresses on the contact surface of operating tools (punch and die) are assigned implicitly, which leads to the mixed boundary-value problem. The results are obtained on the basis of the solution of the constitutive differential equations presenting plane plastic flow in curvilinear characteristic coordinates. The material functions required for the analysis of deep drawing were obtained by experimental studies of ductile damage and failure of pure copper (cf., Zapara et al., 2011). The process of deformation with discontinuities of the tangential velocities at the plastic zone boundaries is discussed. An estimate of the local strains and damage in the material is given both for the plastic zone and for its boundaries. The distributions of strains and of the damage within the wall of a finished part are determined. These distributions strongly affect the strength properties of a shell. The modeling of ductile damage in a material during deep drawing is based on experimental results and considerably extends them for a wider range of stress triaxialities. It is shown that the use of a drawing die with a cone angle of 12°...13° leads to a noticeable shift of the stress triaxialities into a range of negative values as compared to deep drawing with a die of larger angle ( 15°...18° ). The modeling reveals a smoother increase and decrease in damage of the finished part in case of the smaller cone angle as well as the absence of void coalescence. This fact is very important when manufacturing such products at high operating speeds. The obtained results in combination with similar ones from the literature can be applied to the analysis of metal forming processes with dominant tensile deformation (e.g., drawing, deep drawing, stripdrawing, ironing)

Yläkulmahampaiden ja lateraali-inkisiivien juuren kehitysvaihe suhteessa päällekkäin kuvautumiseen ja kulmahampaan kallistuneisuuteen PTG-kuvista

Tiivistelmä. Johdanto: Yläleuan kulmahampaiden ektooppinen puhkeaminen ja impaktoituminen ovat yleisesti tavattavia kliinisiä ongelmatilanteita. Kulmahampaan puhkeamishäiriöiden varhainen tunnistaminen ja hoito on tärkeää, jotta vältytään kalliilta ja aikaa vieviltä hoitojaksoilta. Seurattaessa kulmahampaiden kehittymistä ja puhkeamista röntgenkuvien ottaminen on yleensä indikoitua, jos kliinisesti palpoimalla ja tarkastelemalla ei saada varmuutta normaalista puhkeamisesta. Tutkimuksen tarkoitus: Tutkimuksessa tarkastellaan yläkulmahampaiden ja lateraali-inkisiivien juurten kehitysvaiheita hampaiston vaihduntavaiheessa olevilla lapsilla, kun hampaistossa on I-vaihdunta valmis. Lisäksi yläkulmahampaan ja lateraali-inkisiivin juurenkehitysvaiheita verrataan niiden päällekkäin kuvautumiseen ja kulmahampaan kallistuneisuuteen panoraamaröntgenkuvassa. Tutkimusaineisto ja -menetelmät: Tutkielmassa käytetty tutkimusaineisto koostuu Itä-Suomessa Lapinlahdella vuosina 1980–1996 syntyneiden lasten 1454 PTG kuvasta. Tutkimus on retrospektiivisesti toteutettu rekisteritutkimus. Lasten ikä kuvanottohetkellä on ollut keskimäärin 9,3 vuotta. Tulokset: Tuloksista nähtiin, että suurin osa kulmahampaista tässä ikäkohortissa oli kehitysvaiheeltaan yli kolmasosa, mutta enimmillään noin puolessa välissä lopullista pituutta. Lateraali-inkisiiveillä juurenkehitys oli kesken 75,7 % ja vain 21,5 % oli juurenkehitykseltään valmiita. Kulmahampaan ja lateraali-inkisiivin päällekkäisyyttä ilmeni 45,6 % tapauksista ja päällekkäisyys oli yleisintä kulmahampaan varhaisimmissa kehitysvaiheissa. Yläkulmahampaista 83,8 % kallistuskulma yläleuan keskilinjaan nähden oli alle 20 astetta. Suuremmassa kulmassa kallistuneita yläkulmahampaita esiintyi lähinnä juurenkehityksen puolivälissä ja tätä ennen. Suurimmalla osalla lapsista (83,7 %), joilla lateraali-inkisiivin juurenkehitys oli valmis, oli yläkulmahampaan kulma alle 15 astetta. Johtopäätökset: Tutkimuksen mukaan kolmella neljästä ikäkohortin lapsista kulmahampaiden kehitysvaihe oli kuvanottohetkellä enintään puolivälissä ja päällekkäisyyttä lateraali-inkisiivin kanssa oli lähes puolella tapauksista. Päällekkäisyyden arvioidaan olevan osa normaalivaihtelua varhaisessa kulmahampaan kehitysvaiheessa. Kulmahampaan ja lateraali-inkisiivin kehitysten edetessä päällekkäisyys vähenee ja kallistuneisuus pienenee