Author: Haidong Ji

  • Using rsync to backup remote n00 files

    I had trouble rsync remote Linux 600 files (rw——-) today. I knew that I came across this issue before but couldn’t remember how I resolved it. Therefore I had to waste time looking for and verifying a solution. Hence this blog post. This is the problem I had earlier: [code language=”bash”] rsync -zr userA@remoteServer:/var/www/website/ /home/user/Documents/webSiteBackup/website/www/ […]

  • Grant full permission to Windows folders and files

    For a Windows application or service, it is often necessary for either the user or service startup account to have full control to its folders and files. In most cases, this is transparent to the user. It is generally being taken care of by various delegation mechanisms behind the scene. However, this can be a […]

  • sed tricks

    I helped a charity to rebuild a MySQL server and to restore a database with a lot of data of longblob type in the last two days. Fortunately there was a dump backup file for the database in question. However, tables with longblob column(s) were not defined with “ROW_FORMAT=COMPRESSED”. I’d like to restore that database […]

  • Script to generate index rebuild with PAGE compression

    For BI data warehouse databases, since the data does not change much and they typically require a lot of space, it makes a lot of sense to compress the indexes to save space. I came across some BI databases whose indexes were created without compression. We are in the process of migrating those databases to […]

  • 沼气生产利用研究笔记之资料链接篇

    最近读到老家山东省畜牧局在养殖业发展沼气利用的新闻,让我很受鼓舞。我就把最近在网上读到的公开资料在这里汇总一下,希望能有帮助。也提出一些想法和问题,算抛砖引玉。 这里是欧盟和几个波罗的海国家合作搞的BalticBiogasBus项目的网站。该项目目的是利用废弃有机物生产的沼气经提升(提高甲烷含量)后给公交系统提供燃料。由于甲烷燃料的排放仅仅是二氧化碳,比汽柴油排放清洁太多,对改善环境、治理雾霾有极大帮助。 在页面PUBLICATIONS栏目下有非常多好文章,很值得借鉴。比如“在公交系统引进沼气/天然气公车的策略、政策、和行动计划指南”。又如“沼气生产经验和教训”等等。 沼气给公交车提供燃料时其甲烷CH4含量需超过90%。这篇文章是沼气升级的概述,可以和下面Biogasmax项目文章提到沼气升级文章对照来看。 另外,在该网站的NEWS栏目下也有很多好文章,比如这篇就讲到瑞典南部城市马尔默计划利用沼气给研发中的快速公交系统BRT提供燃料。 斯德哥尔摩的大沼气公交: 这里是瑞典Biogasportalen的关于Biogas的比较详尽的介绍,英文版; 这里是欧盟几年前的Biogasmax项目网站,有很多公开的科研成果,很有意思。比如这个pdf文章就讲到给沼气升级的几种途径(water scrubbing等)。该网站列出的其它文章也很有意思; 美国加州大学戴维斯分校的张瑞红教授是厌氧沼气利用专家。美国环保部门EPA上发布的她的分享很有意思。美国能源部网站上也公布了她的另一篇关于沼气生产的技术分享,也很有意思。 张教授主持的沼气生产科研实验工厂。不知老家山东有没有类似研发并迅速推广应用到实际的科研机构和体系。 中国搞沼气生产很多年,成就不小,但现在在规模、效率、发电上网等方面有一些挑战。这里看到农业部李景明的文章,很有启发。我以为浙江省农业厅的沈其林的一些建议也不错。 我知道老家多年前推广过沼气,但那基本上都是农村的家用池,最终效果,据我的了解,并不太理想。所以在以后的推广中,再单纯走个体农户家用池的筹建推广补贴不见得是好办法。相反,如以镇或县为单位集中筹建消耗本地有机废物,发挥规模效应,我想效果应当会更好些吧。 在沼气利用方面,也要根据实际条件搞多样性利用来有效促进其发展:如在政策和财政方面给沼气发电入网获利提供便利;给村民提供廉价沼气做生活燃料;沼气提升后注入已有天然气管网;或如欧盟一些国家一样搞沼气公交等。 照片来源: 美国加州大学戴维斯分校张瑞红教授主持的沼气生产设施 斯德哥尔摩的大沼气公交