Iron removal from waterlogged wood: Extraction by electrophoresis and chemical treatments     

《文物保护研究》2013,58(3):155-171

Abstract

The presence of iron oxides (lepidocrocite, goethite) in archeological wood may result in a degradation of the wood matrix. Extraction of these iron oxides is largely dependent on their solubility. In this study, balsa wood samples were impregnated with iron oxides to test extraction treatments. Additionally, archeological wood samples were also examined to determine treatment efficiency. Electrophoresis and simple immersion treatments were performed using various chemical solutions: a neutral and a conductive substance (potassium nitrate), an acid (acetic acid), three alkaline chelating agents (tri-ammonium and tri-sodium citrate and sodium oxalate), three acidic and slightly acidic chelating agents (ethylenediaminetetraacetic acid (EDTA), citric acid, and oxalic acid), and a reductant (sodium dithionite). Potassium nitrate did not extract sufficient amounts of iron, irrespective of whether the treatment was conducted by electrophoresis or simple immersion; any observable dissolution was attributed to protonation because of the acidic pH around the anode (as low as 3). Dissolution in acetic acid did not extract iron with either treatment. Strong chelating agents improved extraction, and these compounds gave the best results for simple immersion, particularly EDTA. This chemical is well adapted for use on archeological objects because of its chemical properties (stability constant, speciation based on pH). The addition of sodium dithionite to the solution improved dissolution. Even though electrophoresis improved extraction (in particular for tri-ammonium citrate), none of the tested chelating chemicals were suitable for electrophoresis because of a significant increase in temperature as well as high anode corrosion. The presence of iron sulfide in the archeological wood limited the effectiveness of the tested chemicals. A pre-treatment in sodium persulfate was expanded to include oxidized iron sulfide in oxy/hydroxide iron, which improved the extraction rate.  相似文献   

Removal of Organic Acids from Indoor Air in Museum Storage Rooms by Active and Passive Sorption Techniques     

Signe Hjerrild Smedemark  Morten Ryhl-Svendsen  Jørn Toftum 《文物保护研究》2020,65(5):251-261

ABSTRACT

Adsorbent materials can be used for the removal of organic acids from air in storage rooms with heritage collections. The organic acid removal efficiency of two commercially available activated carbon air-filters were tested in situ in two unoccupied stores with densely packed collections. One filter was designed for outdoor type pollutants (Filter A), while the other was designed for organic acids in indoor air (Filter B). Furthermore, the acetic acid removal efficiency of a desiccant silica gel rotor used for dehumidification was measured in a laboratory at different relative humidity levels. Finally, passive removal of acetic acid by silica gel and unfired clay brick were tested in a chamber, and for clay brick at room level as well. Filter B had the highest removal efficiency. The removal efficiency of both filter types depended on the airflow and the filter performance varied considerably in situ from the values reported from standard laboratory tests. Increasing the filter airflow reduced the removal efficiency from 77% and down to 7% for Filter A, and from 92% to 24% for Filter B. There was almost no effect of active air filtration on the concentration of organic acids when this was measured in the middle and in the corner of the storage rooms away from the ventilation inlets. The desiccant dehumidifier removed 98–100% of the acetic acid from the air, independently of the relative humidity. The desiccant rotor will, however, only be running when there is a need for dehumidification and as a result will only periodically remove pollutants. The high acid removal efficiency by dry silica gel was furthermore demonstrated in a chamber test. A clay brick wall in a test room established a concentration gradient across the room and reduced the concentration of organic acids by 56% compared to close to the emission source.  相似文献   

核桃软糖防粘结初步研究     

李彬 《商洛学院学报》2004,18(2):46-48

针对核桃软糖在气温稍高、温度较大的环境中容易粘结,造成质量下降和贮藏期缩短的现象,通过改进配方和工艺防止和延缓核桃软糖粘结,延长了产品的贮藏时间.  相似文献   

精浆糖蛋白分析及其临床应用     

Lin Peng Fan Qinxin Hua Zongxiang 《大连大学学报》1991,(1)

本文报告了测定精浆糖蛋白总量及聚丙烯酰胺凝胶电泳分析糖蛋白组分的实验方法。对99例正常生育男性的精浆和96例男性不育症患者的精浆糖精浆糖蛋白总量蛋白总量进行了统计学处理。正常精浆糖蛋白总量为2.60±0.73g/dl,不育症患者为3.02±0 64g/dl,t=4.15.P<0.01。在96例不育症中有36例前列腺炎,18例小睾丸,10例副睾炎和6例精索静脉曲张,其糖蛋白总量分别为3.07±0.67g/dl,2.93±0.65g/dl,3.11±0.52g/dl 和2.63±0.92g/dl。与正常精浆相比,t 值显著性检验)分别为3.379(P<0.001),2.481(P<0.02),2.15(P<0.05)和0.095(P<0.05)。本文还对1例正常精浆和4例临床病因不同引起不育者的精浆进行了聚丙烯酰胺凝胶电脉分析,结果提示正常人与不育者在精浆糖蛋白组分上有很大差异,这种差异的临床意义还待进一步研究。  相似文献   

Surface cleaning? Yes,freshly grated Agar gel,please     

Paolo Cremonesi 《文物保护研究》2016,61(6):362-367

Polysaccharide-based rigid hydrogels are by now well-established means for delivering water or, more generally an aqueous solution, to a surface in a controllable way so as to minimize diffusion and possible side-effects on water-sensitive materials during cleaning treatments. These gels can be applied as pre-formed solid bricks on planar surfaces or brushed onto objects in a semi-solid state. In this note, a different application procedure is presented, suitable for surface cleaning treatments of sensitive painted surfaces: pre-formed rigid gels grated to tiny particles that can be brushed onto the surface. A general discussion on the strategies that can be adopted when water is required to clean a water-sensitive soiled surface is presented, then the new procedure is discussed and a representative case study is shown, supporting the procedure described.  相似文献   

蛋白质凝胶电泳及染色方法的几点改进     

陈芳  陈久存 《安康学院学报》2007,19(4):78-80

SDS-聚丙烯酰胺凝胶电泳(SDS-PAGE)及染色技术,是常用测定蛋白质亚基分子量的方法之一,具有设备简单、操作方便和分辨率高等优点.但在操作中,尤其样品较多时,此方法仍然有一些不足之处.通过大量实践,做以下改进:建立根据不同相对分子量的蛋白质快速选择凝胶浓度的方法,并确立解决蛋白质凝胶电泳和染色过程中的常见问题及改进策略.  相似文献   

新生儿窒息母、脐血红细胞流变性变化     

毕胜利  吴一梅  龚玲  杨敬芳 《河北北方学院学报(医学版)》2010,27(1):30-32

目的：探讨新生儿窒息母、脐血中红细胞参数及红细胞电泳指标的变化。方法：胎儿娩出后迅速进行1min的Apgar评分和脐血pH值检测,作为新生儿窒息的诊断标准;选择产后出现急性胎儿窘迫孕妇60例,其中出现新生儿窒息的30例为窒息组,娩出后胎儿正常的30例为窘迫组;另外选择正常足月孕妇30例为对照组。留取母血、脐血,检测红细胞压积（HcT）、平均红细胞体积（MCV）、红细胞体积分布宽度（RDW）等红细胞参数,并进行红细胞电泳等红细胞流变学指标检测。结果：窒息组脐血pH值显著低于其他两组,窒息组脐血与窘迫组和对照组相比MCV及RDW值明显增高,红细胞电泳时间延长,红细胞电泳长度与迁移率明显降低;母血MCV、RDW、红细胞电泳能力等红细胞流变学指标三组之间差异无统计学意义。结论：缺氧窒息可致新生儿脐血红细胞参数、红细胞电泳等流变性指标异常。  相似文献   

天冬酰胺键合硅胶的制备与表征     

黄桂华  高希 《南平师专学报》2010,29(5):43-47

采用固液相表面化学反应法,以胺丙基硅胶为基质,通过丁二酸酐将胺丙基转化为羧基,以1-乙基-（3-二甲基氨基丙基）碳二亚胺盐酸盐（EDC）和N-羟基琥珀酰亚胺（NHS）为羧基活化剂,制备了天冬酰胺键合硅胶。利用元素分析、X射线光电子能谱分析和紫外吸收光谱分析对键合硅胶表面功能团进行表征,结果表明天冬酰胺成功键合到硅胶表面,键合量为0.6mg/g。  相似文献   

水胶炸药PVC药管装药机的研制     

熊献忠  黄文尧  朱福元  王晓光  林磊  马维烈 《淮南职业技术学院学报》2010,10(1):31-33

用PVC药管装的水胶炸药,运用于矿井煤巷深孔预裂控制松动爆破,PVC药管装药机是水胶炸药生产线中主要设备之一;介绍了该设备的装药要求、设计基本原则、工作原理与性能参数;根据现场应用情况,该设备的特点解决了PVC药管装药的连续化生产。  相似文献   

Multiple Myeloma: A Case of Atypical Presentation on Protein Electrophoresis     

Nihar Ranjan Dash  Biswajit Mohanty 《Indian journal of clinical biochemistry : IJCB》2012,27(1):100-102

Multiple myeloma is a group of B-cell disorders resulting in the secretion of a specific and unique monoclonal immunoglobulin (M-protein). Protein electrophoresis is advised whenever multiple myeloma is suspected. The monoclonal protein migrates as a single entity in the electric field and is detected by the non-specific protein stain as a more intensely stained band superimposed on the usual protein pattern. The M-protein usually migrates in the gamma or beta region of the normal protein pattern; very rarely it may appear in the α2 or even in α1 region. Here we have given an atypical case presentation where the patient with multiple myeloma presented with two M-spike one each in α2 and β-globulin region on agarose gel protein electrophoresis with hypoglobulinemia but with reversed A:G ratio.  相似文献