An inductively coupled plasma-time-of-flight mass spectrometer for elemental analysis. Part II: Direct current quadrupole lens system for improved performance

An electrostatic quadrupole lens has been substituted for a cylindrical lens system used in the original inductively coupled plasma-time-of-flight mass spectrometer (ICP-TOFMS). With an improved vacuum system also installed, the cylindrical and quadrupole lenses are compared to each other and to the performance of the prototype ICP-TOFMS. The quadrupole lens requires no tradeoff between ion throughput and resolving power as was encountered with cylindrical lenses. The background noise in both ion-optical systems is within the same order of magnitude. Images of the ion beam formed by each ion-optical system have been obtained on a microchannel plate-phosphor screen. The quadrupole lens shows a higher ion-beam flux and produces a slitlike focus required in the orthogonal ICP-TOFMS instrument. Signal-to-noise ratios in the ICP-TOFMS can be improved by using a technique called pulsed-ion injection that is particularly convenient with the quadrupole lens. In this technique, one quadrupole electrode is pulsed to prevent ions from entering the extraction zone except when an ion packet is to be extracted for mass analysis. This technique significantly reduces the noise over continuous ion injection. In the orthogonal ICP-TOFMS with pulsed-ion injection, 0.5 frnol of analyte could be detected in 1.4 ms with a proper data acquisition system. Overall, the combination of a quadrupole lens and pulsed-ion injection may provide detection limits for the ICP-TOFMS that are competitive with those of quadrupole inductively coupled plasma-mass spectrometry instruments

Grain refinement of magnesium alloys: a review of recent research, theoretical developments and their application

This paper builds on the ‘‘Grain Refinement of Mg Alloys’’ published in 2005 and reviews the grain refinement research onMg alloys that has been undertaken since then with an emphasis on the theoretical and analytical methods that have been developed. Consideration of recent research results and current theoretical knowledge has highlighted two important factors that affect an alloy’s as-cast grain size. The first factor applies to commercial Mg-Al alloys where it is concluded that impurity and minor elements such as Fe and Mn have a substantially negative impact on grain size because, in combination with Al, intermetallic phases can be formed that tend to poison the more potent native or deliberately added nucleant particles present in the melt. This factor appears to explain the contradictory experimental outcomes reported in the literature and suggests that the search for a more potent and reliable grain refining technology may need to take a different approach. The second factor applies to all alloys and is related to the role of constitutional supercooling which, on the one hand, promotes grain nucleation and, on the other hand, forms a nucleation-free zone preventing further nucleation within this zone, consequently limiting the grain refinement achievable, particularly in low solute-containing alloys. Strategies to reduce the negative impact of these two factors are discussed. Further, the Interdependence model has been shown to apply to a broad range of casting methods from slow cooling gravity die casting to fast cooling high pressure die casting and dynamic methods such as ultrasonic treatment

本校學生志工 揮灑色彩 轉變社區新氣象

[[abstract]]位於彰化縣花壇鄉的白沙社區，去年十月有一群大學生進入當地，開始為期十三週的社區微整形計畫。當地居民表示，此行動改變了社區長期單調的風貌，為此地注入活力，並增進居民之間的凝聚力。這是一群來自國立彰化師範大學的同學們，彩繪三個月左右的成果，由輔導與諮商學系的系學會主辦，帶領系上同學透過彩繪實踐服務學習的精神，也與當地的居民一同創作社區圍牆，體驗彩繪的樂趣！ 　　彩繪社區的主題十分豐富且貼近當地文化特色，亦與農特產結合，例如龍眼及竹筍，更融合社區特色的當地「迎燈排」的民俗活動，期望新一代的青年能對於社區文化有更深的認識與認同。 　　活動主辦人之一的楊芷惟同學表示，當初想要舉辦此創新的活動是因為一直以來都有一個走入偏鄉彩繪的夢想，希望可以讓「美」圍繞在居民的生活中。在彩繪過程中，白沙社區發展協會提供了所有的油漆與畫具，讓同學們進行彩繪。此外，當地社區媽媽們的熱情招呼與準備的下午點心讓大學生印象深刻，享受社區的人情味。 　　彩繪社區服務計畫成果發表會於104年1月16日在本校明德館舉行，白沙社區發展協會及白沙國小代表社區頒發服務證書給參與的同學們，感謝此群大學生為社區穿上新衣，增添生命力。此成果發表會不僅讓服務的大學生回顧這些日子彩繪的點滴，檢視自己投入社區的成果，更讓社區居民們看見社區的轉變。 　　為期十三週的彩繪社區服務計畫雖然已於日前落幕，但服務的溫度依然延續，也期盼這份熱情能影響更多的大學生，投入社區服務。（輔導與諮商學系

Caring for a relative with dementia: family caregiver burden

Aim. This paper is a report of part of a study to investigate the burden experienced by families giving care to a relative with dementia, the consequences of care for the mental health of the primary caregiver and the strategies families use to cope with the care giving stressors. Background. The cost of caring for people with dementia is enormous, both monetary and psychological. Partners, relatives and friends who take care of patients experience emotional, physical and financial stress, and care giving demands are central to decisions on patient institutionalization. Method. A volunteer sample of 172 caregiver/care recipient dyads participated in the study in Cyprus in 2004–2005. All patients were suffering from probable Alzheimer’s type dementia and were recruited from neurology clinics. Data were collected using the Memory and Behaviour Problem Checklist, Burden Interview, Center for Epidemiological Studies-Depression scale and Ways of Coping Questionnaire. Findings. The results showed that 68Æ02% of caregivers were highly burdened and 65% exhibited depressive symptoms. Burden was related to patient psychopathology and caregiver sex, income and level of education. There was no statistically significant difference in level of burden or depression when patients lived in the community or in institutions. High scores in the burden scale were associated with use of emotional- focused coping strategies, while less burdened relatives used more problemsolving approaches to care-giving demands. Conclusion. Caregivers, especially women, need individualized, specific training in how to understand and manage the behaviour of relatives with dementia and how to cope with their own feelings