1,740 research outputs found
Innovative techniques in school level micro-scale chemistry experiments part (I) Collection of Distillate at the Source (CDS) technique [1]
Traditional distillation setup collects distillate at a certain distance from the boiling source. This results in loss of product and the situation could be very serious if micro-scale method is employed. By using an innovative design, it is possible to collect nascent distillate immediately after vapor condensation at the boiling source. This is the rationale of designing the Collection of Distillate at the Source (âCDSâ) technique. The design not only significantly improves product yield, because cooling water used for condensation can be dispensed with or recycled. This offers a helpful means to enhance studentsâ âGreen awarenessâ. Two designs using the âCDSâ technique are introduced, namely (i) Micro-scale water-less reflux and distillation and (ii) Micro-scale recycled coolant and all-glass reflux and distillation. The first design can be totally homemade with local resources and by acquiring decent workshop skills, details of construction of its various components are provided
Innovative school-level quantitative chemistry experimental technique (III): A conductivity meter designed for micro-scale use in schools
The paper is a continuation of Part (II) of the article [1] published in AJCE Vol 10 No.2, July, 2020. It also advocates the use of âDMM displayâ technique in which a single piece of instrument, a digital multi-meter (DMM), is used as a terminal display for more than one type of experiment. Sensor circuit design aims at providing a âunit-freeâ display situation in which students feel less threatening, i.e. a âuser-friendlyâ situation for school-level experimentation. The designed electronic sensor, coupled with an innovative miniature conductivity probe, a combo-well plate and a commercial DMM, is able to numerically display electrical conductivity of aqueous solutions ranging from non-conductive like deionized water as 0 to highly conductive such as 1M H2SO4 as 81, with a complete conductance calibrated at 100. The design allows digital display of conductivity measurement of aqueous solutions without the conventional reading unit of âÎŒS/cmâ
Innovative school-level quantitative chemistry experimental technique (i): pH measurement by antimony electrode
This paper introduces the principles of pH measurement by antimony/copper(II) combination electrodes, use of an innovative mini âsalt-plugâ and details for the construction of the electrodes and an electronic sensor. Raw e.m.f. signals generated by the combination electrode are amplified by the sensor which is pre-set to give an analogue output voltage of 10 mV per pH. The voltage displayed by a commercial low-cost digital multimeter (DMM) can be treated as the pH value. The âDMM displayâ technique works for measurements of conductance and colour intensity as well as pH, provided that suitable sensors are used
Editorial overview: Relational values: what are they, and what's the fuss about?
Relational values as preferences, principles and virtues about human-nature relationships have attracted a great deal of attention in recent years. The term has been used to include concepts and knowledge from a wide range of social sciences and humanities, e.g., importantly making space for qualitative approaches often neglected within environmental management and science. Meanwhile, crucial questions have emerged. What counts as a relational value, and what does not? How do relational values (RVs) compare with other value categories and terms, including held, assigned, instrumental, moral, shared, social, and non-material values (e.g., associated with cultural ecosystem services)? In this article, we address these issues, partly by providing context about how the RV term originated and how it has evolved to date. Most importantly, because of their somewhat unique combination of groundedness and moral relevance, positive relational values may offer important opportunities for the evolution of values that may be necessary for transformative change towards sustainability. The special issue includes contributions that contemplate particular concepts (e.g., care, stewardship, eudaimonia human flourishing), applications (e.g., environmental assessment, environmental policy design), and the history of relevant scholarship in various intellectual traditions (e.g., ecological economics, human ecology, environmental education). Together with this suite of thought-provoking papers, we hope that the clarification we provide here facilitates a broad and productive interdisciplinary exchange to create and refine a reflective but powerful tool for sustainability and justice. © 2018We have been funded by a Canadian SSHRC Insight Grant (#435-2017-1071) and a UBC Killam Research Fellowship (KC)
Limb Idleness Index (LII): a novel measurement of pain in a rat model of osteoarthritis
SummaryObjectivesMechanical allodynia during ambulation in osteoarthritis (OA) animal models can be assessed as decreased extent of loading or decreased duration of loading. We propose to measure gait adaptation to pain by both mechanisms with the development of Limb Idleness Index (LII) in a rat model of knee OA.MethodsRats were assigned to anterior cruciate ligament transection (ACLT), Sham, or Normal group (n = 6). Gait data were collected at pre-injury, 1, 2, 3 and 6 months post-injury. Ratios of target print intensity, anchor print intensity, and swing duration were combined to obtain LII. The association of gait changes with pain was assessed by buprenorphine treatment at 3 and 6 months post-injury. At 6 months, OA-related structural changes in knee joints were examined by ÎŒCT and results from histological scoring were correlated with LII.ResultsAs compared to pre-injury level (range 0.75â1.20), LII in ACLT group was increased at 6 months post-injury, which was significantly higher than that in Sham and Normal groups (P = 0.024). The increase in LII in ACLT group was effectively reversed by buprenorphine treatment (P = 0.004). ACLT group exhibited a significantly higher maximum Osteoarthritis Research Society International (OARSI) score as compared to Sham (P = 0.005) and Normal (P = 0.006) groups. Significant correlation was found between LII and side-to-side difference in OARSI score (r = 0.893, P < 0.001).ConclusionsLII presents a good measurement for OA-related knee pain in rat model
The Zero Initial in Chinese: A Preliminary Exploration into D2 and L2 Acquisition
The Chinese syllable traditionally consists of an initial and a final. If no overt consonant occupies the syllable-initial position, a zero initial (Ă) is placed there. This slot is often not empty, however, but contains a multitude of phonetic variants depending on such factors as (sub)dialectal differences and the phonetic properties of the following vowel. This small, preliminary study, making use of simple, visual inspection of waveforms and spectrograms in Praat, contributes to issues of facilitation and interference in D2 and L2 acquisition. The focus is on the zero initial before high vowels in the following three settings: within the Yue dialects (Zhongshan, standard Cantonese), across varieties of Chinese (Mandarin, Yue), and across languages (Chinese, English)
- âŠ