Search results

1 – 2 of 2
Per page
102050
Citations:
Loading...
Access Restricted. View access options
Article
Publication date: 15 June 2010

Lino Costa, Deepak Rajput, Kathleen Lansford, Wenqiang Yue, Alexander Terekhov and William Hofmeister

The purpose of this paper is to develop a simple, easy to implement powder delivery strategy for solid freeform fabrication (SFF) processing.

660

Abstract

Purpose

The purpose of this paper is to develop a simple, easy to implement powder delivery strategy for solid freeform fabrication (SFF) processing.

Design/methodology/approach

A specially designed “tower nozzle” located at the center of the processing area dispenses the feedstock powders continuously and uniformly onto the processing area, where powders accumulate progressively as a flat powder bed. During the dispensing, powders are selectively consolidated by melting and solidification using a laser beam which was scanned in a predefined pattern using a galvo‐mirror scan head.

Findings

Experiments performed with AISI H13 steel show that the tower nozzle powder delivery strategy is suitable for SFF processing.

Practical implications

Both powder delivery and laser consolidation are performed simultaneously and without interruption with simple apparatus. No powder delivery scrapers or rollers are used.

Originality/value

The main characteristics of a prototype tower nozzle and the typical processing conditions used to form thin wall AISI H13 steel shapes are presented.

Details

Rapid Prototyping Journal, vol. 16 no. 4
Type: Research Article
ISSN: 1355-2546

Keywords

Access Restricted. View access options
Book part
Publication date: 25 November 2019

Xing Zhang

Depressive symptoms are higher among racial and ethnic minorities in the United States. Many studies have evidenced associations between school disconnectedness and depressive…

Abstract

Depressive symptoms are higher among racial and ethnic minorities in the United States. Many studies have evidenced associations between school disconnectedness and depressive symptoms by race and ethnicity in adolescence (Joyce & Early, 2014; Walsemann, Bell, & Maitra, 2011). Given that adolescents spend most of their time at home when they are not at school (Larson & Richards, 2001), it is important to understand how mother-child relationships may moderate school disconnectedness, and how mother–child relationships may serve as a protective buffer for depressive symptoms in the transition to adulthood. I use data from Waves II and III of the National Longitudinal Study of Adolescent to Adult Health (Add Health) from 1995 to 2002 (n = 9,766) and OLS regression analysis to examine how school disconnectedness in adolescence is associated with depressive symptoms in the transition to adulthood, and how mother–child relationships in adolescence moderate these associations in the United States. I examine differences in these relationships across racial and ethnic groups. I find that school disconnectedness in adolescence is associated with increased depressive symptoms in the transition to adulthood, and that maternal warmth and communication moderates the association between school disconnectedness and depressive symptoms. Maternal relationship quality in adolescence serves as an important protective factor for mental health in the transition to adulthood.

Details

Transitions into Parenthood: Examining the Complexities of Childrearing
Type: Book
ISBN: 978-1-83909-222-0

Keywords

1 – 2 of 2
Per page
102050