Property-tax exemptions and the fiscal crisis of central US cities

Fiscal disparities between US central cities and their suburban communities have long been recognized. Many older medium-sized and large cities in the North-eastern and North-central regions of the USA are suffering from a continuous decline in their tax bases. Governments of aging central cities have lost much of their tax base to the expanding suburban jurisdictions and are unable to generate the revenue needed to meet the growing public service demands placed upon them.     

Low-Temperature Superplastic Deformation of Cold-Rolled Fe–5.6Mn–1.1Al–0.2C Steel

Metallurgical and Materials Transactions A - A cold-rolled low Al-added medium Mn steel was employed to investigate the low-temperature superplastic deformation at a relatively high initial strain...     

Cooperative adsorption behavior of fatty acid methyl esters from hexadecane <Emphasis Type="Italic">via</Emphasis> coefficient of friction measurements

The frictional behaviors of methyl oleate (MO), methyl palmitate (MP), methyl laurate (ML), and methyl stearate (MSt) as additives in hexadecane have been examined in a boundary lubrication test regime using steel contacts. It was found that the transient attributes of coefficient of friction (COF)-time spectra are a sensitive measure of adsorption equilibria. Critical additive concentrations were defined and used to perform novel and simple Langmuir analyses that provide an order of adsoprtion energies: MSt>MP>MO≥ML. Application of Langmuir, Temkin, and Frumkin-Fowler-Guggenheim adsorption models via nonlinear fitting of a general cooperative model demonstrates the necessary inclusion of cooperative effects in the applied model. In agreement with the qualitative features of steady-state COF-concentration plots, MSt modeling requires minimal cooperative interaction terms. However, MO, MP, and ML data require large attractive interaction terms to be adequately fitted. Primary adsorption energies calculated via the cooperative model are necessarily decreased, whereas total adsorption energies correlate well with values obtained via critical concentration analyses. These results and comparisons with previous adsorption studies of MO and MSt suggest that primary (ester-surface) and secondary (alkyl-surface) adsorbate-adsorbent, adsorbate-adsorbare, and (free-additive) adsorpt-adsorpt interactions collectively determine both the calculated primary and the cooperative interaction energies.     

Application of ionic liquids for the removal of heavy metals from wastewater and activated sludge

This paper presents the results of adsorption studies on the removal of heavy metals (Cr, Cu, Cd, Ni, Pb and Zn) from standard solutions, real wastewater samples and activated sewage sludge using a new technique of liquid-liquid extraction using quaternary ammonium and phosphonium ionic liquids (ILs). Batch sorption experiments were conducted using the ILs [PR4][TS], [PR4][MTBA], [A336][TS] and [A336][MTBA]. Removal of these heavy metals from standard solutions were not effective, however removal of heavy metals from the industrial effluents/wastewater treatment plants were satisfactory, indicating that the removal depends mainly on the composition of the wastewater and cannot be predicted with standard solutions. Removal of heavy metals from activated sludge proved to be more successful than conventional methods such as incineration, acid extraction, thermal treatment, etc. For the heavy metals Cu, Ni and Zn, ≥90% removal was achieved.     

Characterization and microstructure of highly preferred oriented lead barium titanate thin films on MgO (100) by sol-gel process

Highly preferred oriented lead barium titanate (Pb_1−x,Ba_x)TiO₃ thin film, with particular emphasis on (Pb_0.5,Ba_0.5)TiO₃, can be obtained by spin-coating on MgO (100) substrate by using the precursor sol, which was synthesized from acetylacetone chelating with titanium isopropoxide and ethylene glycol as a solvent, in the sol-gel process. Film thickness, pyrolysis temperature and heating rate were studied systemically to investigate their influences on the formation of preferred oriented thin films. The highly preferred (001)/(100) oriented thin film could be obtained by the pyrolysis of wet film at 500 °C and annealing at 600 °C at a slow heating rate of 5 °C/min. It is confirmed that the tetragonal perovskite structure of the titanate ceramic decreases with an increase of Ba content in (Pb_1−x,Ba_x)TiO₃. The (001)/(100) oriented films were synthesized from all compositions between x = 0.2 and x = 0.8, at a crystallization temperature of 600 °C. In particular, for the Ba content in the range of x = 0.50.6, highly preferred (001)/(100) planes were observed.     

多频超声波辅助磷脂酶处理对菜籽油脱胶效果及品质的影响

采用多频超声波技术对菜籽油的酶法(磷脂酶A1)脱胶效果及其脱胶后油品质变化展开了相关研究。结果表明,多频超声波作用能有效地提高磷脂酶A1对菜籽油的脱胶效率,大幅度降低脱胶后菜籽油中的含磷量;并且20/50 kHz双频超声处理对菜籽油的脱胶效果最佳。与磷脂酶A1脱胶后菜籽油相比,超声波作用后的脱胶油酸价和过氧化值略有上升(均在国家标准所规定的安全范围内),色泽变浅,脂肪酸组成的数值变化不明显。     

脱脂小麦胚芽蛋白分类及其氨基酸组成分析

对脱脂小麦胚芽蛋白进行Osboren分类研究,进一步研究了各蛋白组分的亚基分子质量分布、氨基酸组成和营养价值.试验结果表明,球蛋白和清蛋白是小麦胚芽蛋白的主要组分.SDS-PACE分析中,清蛋白主要亚基分子质量为15 000、17 400、20 500、29 000、33 400～37 100和54 900 u.球蛋白主要亚基分子质量为12 300、20 000、23 500、36 000～40 100和47 000～55 200 u,谷蛋白的主要亚基分子质量为55 000、41 800和＜27 000 u.同时,试验结果也表明,清蛋白的氨基酸评分最高,其次分别为谷蛋白、球蛋白和醇溶蛋白;清蛋白具有最高的蛋白质效率比(PER)和体外消化率(IVPD),醇溶蛋白和谷蛋白的PER和IVPD较小;清蛋白的蛋白质消化率校正的氨基酸记分法(PDCAAS)最高,球蛋白、醇溶蛋白和谷蛋白的PDCAAS较小.因此,与FAO/WHO模式相比,清蛋白具有较好的氨基酸组成和PDCAAS,是一种优质蛋白质.     

西红柿催化红外去皮过程三维传热模型的建立和设备能耗计算

为提高西红柿红外干法去皮的加工性能,本研究建立了红外辐射加热的三维传热模型,利用该模型对西红柿红外去皮过程中表面和内部不同位置的温度进行预测,并通过比较温度预测值和实测值来验证模型的拟合度;进一步通过能耗计算对比分析两种不同的红外设备,筛选出较优的红外设备。结果表明,与静态催化红外设备相比,燃气-滚轮传送式催化红外设备可以实现对西红柿表皮的快速加热（表面最高温度为60.32℃）,且西红柿表面温度分布更均匀（最大温差约6.44℃）;内部温度增幅较低（内部最高温度为49.10℃）,且内部温度分布也较均匀（最大温差约18.25℃）。模型预测值与实测值之间的拟合较好（R2≥0.93）,且两者之间的估计标准误差EESE值较低（0.13～10.80℃）,表明三维传热模型的拟合效果良好,能够很好地反映不同红外设备下西红柿表面和内部的温度分布。与静态式催化红外设备相比,燃气-滚轮传送式催化红外设备更优,即缩短了16.60%的加工时间,又节约了34.80%的能耗,更高效节能,在果蔬去皮领域具有广阔的应用前景及工业化推广价值。