4,511 research outputs found
(p -Cymene)thioglycollatoruthenium(II) dimer; a complex with an ambi-basic S,O-donor ligand
The title compound was prepared from the (p-cymene)ruthenium chloride dimer and thioglycollic acid. The structure is a centrosymmetric dimer bridged by the soft-base S atoms, with the hard-base O atoms of the carboxylate group chelating to form a five-membered twisted-ring. The coordination of the ruthenium atoms is completed by a η6-p-cymene ligand, giving an 18-electron count. The Ru–S bonds are essentially equal at 2.396(1) Å
Assessing the potential for reopening a building stone quarry : Newbigging Sandstone Quarry, Fife
Newbigging Sandstone Quarry in Fife is one of a number of former quarries in the Burntisland-
Aberdour district which exploited the pale-coloured Grange Sandstone from Lower
Carboniferous rocks. The quarry supplied building stone from the late 19th century, working
intermittently from 1914 until closure in 1937, and again when reopened in the 1970s to the
1990s. The stone was primarily used locally and to supply the nearby markets in the Scottish
Central Belt.
Historical evidence indicates that prior to sandstone extraction, the area was dominated by largescale
quarrying and mining of limestone, and substantial sandstone quarrying is likely to have
begun after the arrival of the main railway line in 1890. It is probable that removal of the
sandstone was directly associated with limestone exploitation, and that the quarried sandstone
was effectively a by-product of limestone production. Sandstone extraction was probably viable
due to the existing limestone quarry infrastructure (workforce, equipment, transportation) and the
high demand for building stone in Central Scotland in the late 19th century.
The geology within Newbigging Sandstone Quarry is dominated by thick-bedded uniform
sandstone with a wide joint spacing, well-suited for obtaining large blocks. However, a
mudstone (shale) band is likely to be present within a few metres of the principal (north) face of
the quarry, around which the sandstone bed thickness and quality is likely to decrease. The
mudstone bed forms a plane sloping at a shallow angle to the north, so that expansion of the
quarry in this direction is likely to encounter a considerable volume of poor quality stone.
Additionally, an east-west trending fault is present approximately 100 metres north of the quarry
face, which is also likely to be associated with poor quality (fractured) stone
On the Delay of Network Coding over Line Networks
We analyze a simple network where a source and a receiver are connected by a
line of erasure channels of different reliabilities. Recent prior work has
shown that random linear network coding can achieve the min-cut capacity and
therefore the asymptotic rate is determined by the worst link of the line
network. In this paper we investigate the delay for transmitting a batch of
packets, which is a function of all the erasure probabilities and the number of
packets in the batch. We show a monotonicity result on the delay function and
derive simple expressions which characterize the expected delay behavior of
line networks. Further, we use a martingale bounded differences argument to
show that the actual delay is tightly concentrated around its expectation
MEASURING THE EFFECTIVENESS OF A TWO-PERIOD ALGEBRA CLASS: A PROGRAM EVALUATION
This paper details a program evaluation of a two-period freshman Algebra course in a two-high school district. The study examines the degree to which the two-period course is an effective intervention for freshman math students as compared to the one-period freshman Algebra course by reviewing student assessment data, student growth indicators, and course enrollment data. In addition to quantitative data, student, teacher, and administrator perceptions of the course inform the investigation into the two-period remedial math class. The paper concludes that the two-period math program is not having the desired impact and should be reconfigured or reconsidered altogether
BLOCK SCHEDULING FOR THE 21ST CENTURY HIGH SCHOOL: A CHANGE LEADERSHIP PLAN
The needs of 21st Century learners require an overhaul in the way classroom instruction is organized and delivered. This Change Plan outlines how and why high schools may consider modifying the bell schedule to support needed change. The current high school structure was developed at the turn of the 20th Century, over 100 years ago, when the world was much smaller, and the vast majority of students did not go on to college or need advanced coursework to enter and compete in the workforce. Yet, this late 19th century concept is still the basic organizing structure of our modern day high school that must meet the needs of a much more diverse group of students requiring very different skill sets (DiMartino and Clarke, 2008, p. 7). This Change Plan is about whether and to what extent the traditional 8-period, 50-minute school day effectively meets the needs of 21st century schools as compared to a block or modified block schedule. Three schools are featured in this Change Plan. One traditionally scheduled school (District A), one A/B modified block school (District B) and one 4x4 block schedule school (District C). The results clearly demonstrate dissatisfaction by the teachers and students in the traditionally scheduled school because they feel overwhelmed, disconnected with one another, and unable to dive deeply into needed content and skills. However, teachers in the 4x4 block schedule expressed equal frustration because they feel the schedule is more limiting, not less. The only schedule of the three which seems to hold some promise is the A/B modified block schedule which blends a traditional and block approach. Whatever the final solution, District A needs to study what schedule will best allow their 21st century students to apply needed skills and demonstrate mastery over them
GOING 1:1- WRITING POLICY TO SUPPORT THE 21ST CENTURY STUDENT: A POLICY ADVOCACY DOCUMENT
In an effort to prepare its graduates with the 21st century skills of problem solving, collaboration, technology savvy, creativity, and information literacy and to close the learning gaps between students who have access to technology and those who don’t, this study proposes that District 123 create a policy to support a 1:1 Chromebook initiative. Using Browder’s needs analysis model, the impact of a 1:1 program is analyzed through the educational, social, political, economic and moral frames (Browder, 1995). It is determined that a 1:1 program can transform teaching and learning by giving equal access to technology, by incorporating student-driven and inquiry-based lessons that challenge students to meaningfully utilize resources outside the classroom walls and contribute their voice to the digital sphere. This transition requires significant human and financial capital, as well as careful planning, professional development, curricular and classroom modifications and thoughtful assessment mechanisms. A proposed budget and an assessment plan is included in the study
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