Bringing geography to the community: community-based learning and the geography classroom

Community-based learning is a pedagogical technique designed to bring students out of the classroom and into their communities. Students typically pair with local nonprofit organizations to complete work which ties into their scholarship. Faculty, students, and community members can all benefit from these partnerships, and university-community relations are strengthened by them. These connections deepen the educational experience and improve student success and retention, and build civic engagement skills that benefit the university community and the student’s home community (Strait, Turk, and Nordyke in: JR Strait, K Nordyke (eds), Pedagogy Of Civic Engagement, High-Impact Practices, and e-Service- L Earning, Stylus Publishing, Virginian, 2015; Bednarz in Journal of Geography in Higher Education 32:87–100, 2008; Mohan in Journal of Geography in Higher Education 19:129–142, 1995). Spatial citizenship, while vital to such engagement and to effective community participation, is seldom taught in traditional pedagogy (Kanwischer, Schulze, and Gryl in: Thomas Jekel, Adrijana Car, Josef Strobl, and Gerald Griesebner (eds), Spatial citizenship—dimensions of a curriculum, Wichmann Verlag, Berlin, 2012). Connecting place to pedagogy with spatially-enabled learning helps students investigate complex global concepts at a manageable local scale. Geography is an intrinsic part of scholarship, to varying degrees, and spatial thinking can bring added dimension and value to the educational process (Vogler in: Thomas Jekel, Adrijana Car, Josef Strobl, and Gerald Griesebner (eds), Wichmann Verlag, Berlin, 2012). The intersectionalities which exist within the community, when examined with a spatial lens, are the core of community geography, a praxis-focused method of engaged scholarship (Shannon in Progress in Human Geography, 10.1177/0309132520961468, 2020). Community-based learning is not clearly defined, yet some established models exist. Place-based learning communities move cohorts of students through a curriculum that is centered on local community issues, with the community as both laboratory and lens, and building place attachment (Schweizer, Davis, and Thompson in Environmental Communication 7:42–62, 2013). Service learning, while less clearly defined, typically involves direct work with community organizations, identifying, investigating, and contributing to solutions for local issues (Strait, Turk, and Nordyke in: JR Strait, K Nordyke (eds), Pedagogy Of Civic Engagement, High-Impact Practices, and e-Service- L Earning, Stylus Publishing, Virginian, 2015; Cal Corps Public Service in Designing Community-Based Courses, 1–45, 2015). Built around the concept of place, the added dimension of improved spatial citizenship benefits both community and students. This paper will review community-based learning as practiced through upper-division service learning courses in geography at two universities, and the development of a new course, as methods of engagement with local communities through a spatial lens.

     

Dissolution Kinetics of Calcite in 0.1 M NaCl Solution at Room Temperature: An Atomic Force Microscopic (AFM) Study

Atomic force microscopy (AFM) was used to study the rates of migration of the (10¯1 4) plane of a single-crystal of calcite dissolving in 0.1 M NaCl aqueous solutions at room temperature. The solution pH and P_{CO 2} controlled in the ranges 4.4 < pH < 12.2 and 0 < P_{CO 2} < 10^-3.5 atm (ambient), respectively. Measured step velocities were compared with the mineral dissolution rates determined from the calcium fluxes. The step velocity is defined as the average of the velocities of the obtuse and acute steps. Rates of step motion increased gradually from 1.4(±0.2) at pH 5.3 to 2.4(±0.3) nm s^-1 at pH 8.2, whereas the rates inverted and decreased to the minimum value of 0.69(±0.18) nm s^-1 at pH 10.8. For pH > 10.8, only the velocity of the obtuse steps increased as pH increased, whereas that of acute steps gradually decreased.The dissolution rate of the mineral can be calculated from the measured step velocities and average slope, which is proportional to the concentration of exposed monomolecular steps on the surface. The average slope of the dissolving mineral, measured at pH 5.6 and 9.7, was 0.026 (±0.015). Using this slope, we calculate bulk dissolution rates for 5.3 < pH < 12.2 of 4.9(±3.0) × 10^-11 to 1.8(±1.0) × 10^-10 mol cm^-2 s^-1. The obtained dissolution rate can be expressed by the following empirical equation:R_dss = 10^{-4.66(±0.13)}[H⁺] + 10^{-3.87(±0.06)}[HCO₃ ^-] + 10^{-7.99(plusmn; 0.08)}[OH^-]We propose that calcite dissolution in these solutions is controlled by elementary reactions that are similar to those that control the dissolution of other amphoteric solids, such as oxides. The mechanisms include the proton-enhanced hydration and detachment of calcium-carbonate ion pairs. The detachments are enhanced by the presence of adsorbed nucleophiles, such as hydroxyl and bicarbonate ions, and by protons adsorbed to key oxygens. A molecular model is proposed that illustrates these processes.     

On stress-forecasting strategy of earthquakes from stress buildup, stress shadow and stress transfer （SSS） based on numerical approach

Global Positioning System(GPS) and Interferometric Synthetic Aperture Radar(InSAR),used for monitoring crust deformation,are found to be very promising in earthquake prediction subject to stress-forecasting.However,it is recognized that unless we can give reasonable explanations of these curious precursory phenomena that continue to be seren-dipitously observed from time to time,such high technology of GPS or InSAR is difficult to be efficiently used.Therefore,a proper model revealing the relation between e...     

矿物收藏漫谈(二)矿物晶体ABC你了解多少?

不管你付出过多少,不管你的阅读量多大,也不管你观察过的现象多么丰富,你都不可能了解全部的矿物学知识。事实上你所能了解的只是所有矿物学知识的极少部分。你所能希望的最多是自己比其他人了解得更多些,然而这似乎也多不到哪里去。     

钙质砂在三轴剪切中颗粒破碎评价及其能量公式

钙质砂是一种易破碎粒状材料。本文在分析颗粒破碎机理的基础上,提出了颗粒破碎与剪胀耦合作用的破碎功表示式,并用实验证明了相对破碎Br 与1,Wp,WB 之间的关系,从而建立了钙质砂颗粒破碎的评价指标及其能量公式。     

缓倾内斜坡多层采煤下覆岩变形特征数值模拟研究

贵州省水城县发耳煤矿尖山营变形体、米萝煤矿后山变形体以及兴仁县国保煤矿映山红山变形体是典型的采动斜坡,变形具有显著的矿山地质灾害特征。本文通过对前述三处采动斜坡坡体结构特征总结分析,提出具有代表性的概化工程地质模型,并基于离散元数值模拟方法,对开采三层煤条件下不同采空区排布方式覆岩变形破坏特征进行了研究。研究表明:采空区完全重叠条件下最上层采空区覆岩塌陷最严重,受岩体碎胀性影响岩体塌陷的最大深度小于采空区竖向总厚度;采空区顶板岩体破坏会逐渐向上部岩体传递,这种破坏现象传递至地表后破坏程度相较于采空区顶板减弱,地表塌陷的最大值远小于采空区竖向总厚度,其与采空区重叠面积相关性小;采空区排列的总长度越大,斜坡变形范围越大,但位移量值相较于采空区重叠的情况小;斜坡下部煤层被开采后,采空区上部坡体具有向坡外运动的趋势,坡脚出现显著的应力集中,坡脚岩体对斜坡具有"锁固"效应,扰动坡脚对斜坡稳定会产生不利影响。     

A δS isoscape of total sulphur in soils across Northern Ireland

A map of the spatial variation in isotopic composition of a substrate, or isoscape, provides a tool to address a range of research questions, such as the use of isotope fingerprinting to identify the origin of compounds. The focus of this study was to establish a soil S isotope map for Northern Ireland in order to investigate spatial variability within the isotopic composition of total soil sulphur (S). The sample resolution was about one sample every 141 km². δ³⁴S values were grouped based on soil type and soil parent material. Total soil S δ³⁴S data were grouped according to soil type, to evaluate whether a soil’s characteristics affect its isotopic composition. Gleyed soils had a mean δ³⁴S value of +6.3 ± 6.1‰, lower than the means for other soil types. A trend towards higher δ³⁴S values (mean δ³⁴S of +13.8 ± 6.0‰) was observed in soils with a high organic matter content. No trends in δ³⁴S value were observed for other soil types. There were no discernible correlations between total soil S δ³⁴S and soil parent material, with the exception of shale and mudstones. The majority of soils derived from shale and mudstones had δ³⁴S values at or close to the mean of +4.9‰. A spatially coherent pattern of relatively high soil total S δ³⁴S values in the west and north, and low in the SE, is discernible in Northern Ireland. Based on the observed spatial distribution, it has been concluded that the quantity and source (anthropogenic or marine) of wet atmospheric S deposition is a controlling factor on regional variation of soil δ³⁴S in Northern Ireland. This S isoscape will assist studies of S cycling in Northern Ireland and may assist in the creation of an ‘isotopic fingerprint’ for a potential ‘input’ source needed to interpret data in traceability studies.