检索结果-南通市图书馆

prospective Study and physico-Mechanical Characterisation of Granular Materials Used in the Manufacture of Ordinary Concrete in Congo

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Geomaterials 2025年第1期15卷 1-24页

作者： Jarlon Brunel makela Bienvenu Ebata-Ndion Narcisse Malanda Stanislas Kevin Mbeke Laboratory of Mechanics Energy and Engineering Higher National Polytechnic School Marien Ngouabi University Brazzaville Republic of the Congo Higher Institute of Architecture Building Planning and Public Works Denis Sassou Nguesso University Kintl Republic of the Congo

This research is an experimental study aimed at identifying and determining the physico-mechanical properties of various granular materials used in current concretes based on local aggregates (sands, gravels) from different quarries, highlighting their intrinsic properties. The aim was also to test their specific influence on the cementitious matrix of hardened concrete. Several laboratory tests were conducted on samples from Brazzaville and pointe-Noire. To develop a variety of concrete formulations meeting rheological criteria (deformability, bleeding, segregation) and create an optimal concrete formulation approach considering its microstructural and compacting matrix, a good granular distribution was planned, using two types of sand (rolled and crushed). This involved correcting the rolled sand with variable proportions (30% to 50%) of crushed sand. The results from the eight concrete formulations studied, using the Dreux-Gorisse method, showed that six formulations produced the expected results. Compressive strengths at 28 days ranged from 25 to 36.75 Mpa. As a result, formulation 3 appears to be the best, with a mechanical strength of 36.75 Mpa at 28 days, compared to formulation 1 (33.75 Mpa), formulation 4 (27.25 Mpa), and formulation 2 (26.65 Mpa) for the Brazzaville locality. For the pointe-Noire locality, formulation 8 was judged the best, with a characteristic mechanical strength of 29.70 Mpa at 28 days, followed by formulation 7 (27.30 Mpa), formulation 5 (22.80 Mpa), and formulation 6 (18.30 Mpa). In summary, the concretes formulated with raw sand showed better results than those with improved sands. The same was true for concrete formulations using rolled sand and gravel.

关键词： Sand Gravel Cement Formulation Identification Concrete physical-Mechanical properties

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

2006年欧洲人畜共患病的感染情况报告

中国家禽 2008年第3期30卷 57-58页

作者： J.Denny F.Boelaert B.Borck OE Heuer A.Ammon p.makela

2006年欧洲人畜共患病的感染情况年度总结报告，由欧盟食品安全局（EFSA）和欧洲疾病预防和控制中心（ECDC）于近期公布。该报告阐述了人畜共患病传染、媒介、抗生素抗性和食源性疾病在25个欧盟成员国和5个非成员国（保加利亚、冰岛、... 详细信息

2006年欧洲人畜共患病的感染情况年度总结报告，由欧盟食品安全局（EFSA）和欧洲疾病预防和控制中心（ECDC）于近期公布。该报告阐述了人畜共患病传染、媒介、抗生素抗性和食源性疾病在25个欧盟成员国和5个非成员国（保加利亚、冰岛、列支敦士登、挪威和罗马尼亚）暴发的最新趋势和发生数字。以下是该报告的背景和结果。

关键词：人畜共患病感染情况欧洲欧盟成员国食源性疾病抗生素抗性总结报告控制中心

Divergent expression of bacterial wall sensing toll-like receptors 2 and 4 in colorectal cancer

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2017年第26期23卷 4831-4838页

作者： Karoliina paarnio Sara Vayrynen Kai Klintrup pasi Ohtonen Markus J Makinen Jyrki makela Tuomo J Karttunen Oulu University Hospital and Medical Research Center Oulu Research Unit of Surgery Anesthesia and Intensive CareUniversity of Oulu Cancer and Translational Medicine Research Unit University of Oulu

To characterize the expression of toll-like receptors (TLR) 2 and 4 in colorectal cancer (CRC) and in normal colorectal mucosa. METHODSWe analysed tissue samples from a prospective series of 118 unselected surgically treated patients with CRC. Sections from formalin fixed, paraffin embedded specimens were analysed for TLR2 and TLR4 expression by immunohistochemistry. Two independent assessors evaluated separately expression at the normal mucosa, at the invasive front and the bulk of the carcinoma, and in the lymph node metastases when present. Expression levels in different locations were compared and their associations with clinicopathological features including TNM-stage and the grade of the tumour and 5-year follow-up observations were analysed. RESULTSNormal colorectal epithelium showed a gradient of expression of both TLR2 and TLR4 with low levels in the crypt bases and high levels in the surface. In CRC, expression of both TLRs was present in all cases and in the major proportion of tumour cells. Compared to normal epithelium, TLR4 expression was significantly weaker but TLR2 expression stronger in carcinoma cells. Weak TLR4 expression in the invasive front was associated with distant metastases and worse cancer-specific survival at 5 years. In tumours of the proximal colon the cancer-specific survival at 5 years was 36.9% better with strong TLR4 expression as compared with those with weak expression (p = 0.044). In contrast, TLR2 expression levels were not associated with prognosis. Tumour cells in the lymph node metastases showed higher TLR4 expression and lower TLR2 expression than cells in primary tumours. CONCLUSIONTumour cells in CRC show downregulation of TLR4 and upregulation of TLR2. Low expression of TLR4 in the invasive front predicts poor prognosis and metastatic disease.

关键词： Colorectal Cancer Toll-like receptor 2 Toll-like receptor 4 Inflammation prognosis

Effects of Selenium on Maize Ovary Development at pollination Stage Under Water Deficits

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Agricultural Sciences in China 2008年第11期7卷 1298-1307页

作者： SHEN Qiang-yun Marja Turakainen Mervi Seppanen pirjo makela Department of Applied Biology University of Helsinki P.O. Box 27 Helsinki FIN-O0014 Finland Crop Research Institute Ningxia Academy of Agricultural and Forestry Science Ningxia 750105 P.R. China

Maize ovary development is linked to kernel formation. Soil water deficit results in ovary abortion because of low water potential （ψw） resulting in inhibition of photosynthesis from anthesis to silking stage. Thus, drought is a key factor causing yield losses in maize, especially near the time of pollination. Earlier studies have indicated that selenium （Se） maintains antioxidative defence systems and enhances sugar and starch accumulation. The effects of Se on maize ovary development were studied in drought stress conditions. Maize ovary development was studied through observations on starch, membrane integrity, fresh weight and dry weight in drought-treated or unstressed glasshouse-grown plants, and crop yield, yield structure, leaf, stem and ear biomass accumulation were also analyzed. Results indicated that Se increased the stress tolerance of the crop, even though ovary abortion was not eliminated by Se treatments under low ψw. Under well-watered control conditions, Se had also negative effects. When the first ear was not succesfully pollinated or the ovaries aborted, the plants developed more ears. Even though these later formed ears did not produce kernels, they significantly increased the dry weight of the plants under water deficit. It could be concluded that The optimal concentration for maize of Se applied through roots is about 0.01 mg kg^-1 （supplied as Na2SeO4） soil or less.

关键词： ovary development photosynthesis selenium water deficit Zea mays

Heavy metals leaching in bottom ash and fly ash fractions from industrial-scale BFB-boiler for environmental risks assessment

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Transactions of Nonferrous Metals Society of China 2016年第1期26卷 256-264页

作者： Risto pOYKIO Mikko makela Gary WATKINS Hannu NURMESNIEMI OUi DAHL Department of Environmental protection City ofKemiValtakatu 26FI-94100 KemiFinland Division of Biomass Technology and Chemistry Department of Forest Biomaterials and TechnologySwedish University of Agricultural SciencesP.O.Box SLUSE-90183 UmehSweden Department of Environmental Science and Technology Tokyo Institute of Technology4259 Nagatsuta-choMidori-kuYokohama 226-8502Japan Department of Forest products Technology School of Chemical TechnologyAalto UniversityP.O.Box 16400FI-00076 AaltoFinland Department of Environmental protection Stora Enso OyjVeitsiluoto MillFI-94800 KemiFinland

The bottom ash and fly ash from the co-combustion of wood residues and peat at a bubbling fluidised bed boiler（296 MW） contained only quartz（SiO_2）, microcline（KAl Si_3O_8） and albite（NaAlSi_3O_8）. Thus, X-ray powder diffraction（XRD） was not useful for clarifying the difference in the release of associated heavy metals from ash matrices. In order to assess the release of heavy metals from ashes under changing environmental conditions, they were sequentially extracted and fractionated by the BCR-procedure into acid soluble/exchangeable（CH_3COOH）, reducible（NH_2OH-HCl） and oxidizable（H_2O_2/CH_3COONH_4） phases. The CH_3 COOH extractable fraction in conjunction with the total heavy metals concentrations were used to calculate the risk assessment code values for heavy metals leaching from the ash matrix. The leaching studies indicate that the heavy metals in the bottom ash and fly ash are bound to different fractions with different strengths. From the environmental and utilization perspectives, heavy metals in ashes posed different levels of environmental contamination risk. Only As in the bottom ash posed a very high risk. High risk metals were Cd in the bottom ash as well as As, Cd and Se in the fly ash.

关键词： bottom ash fly ash BCR extraction heavy metals risk assessment code

Mobility Trigger Management: Implementation and Evaluation

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

International Journal of Communications, Network and System Sciences 2009年第3期2卷 211-221页

作者： Jukka makela Kostas pENTIKOUSIS Vesa KYLLONEN VTT Technical Research Centre of Finland Oulu Finland

Modern mobile devices have several network interfaces and can run various network applications. In order to remain always best connected, events need to be communicated through the entire protocol stack in an efficient manner. Current implementations can handle only a handful of low level events that may trigger actions for mobility management, such as signal strength indicators and cell load. In this paper, we present a framework for managing mobility triggers that can deal with a greater variety of triggering events, which may originate from any component of the node’s protocol stack as well as mobility management entities within the network. We explain the main concepts that govern our trigger management framework and discuss its architecture which aims at operating in a richer mobility management framework, enabling the deployment of new applications and services. We address several implementation issues, such as, event collection and processing, storage, and trigger dissemination, and introduce a real implementation for commodity mobile devices. We review our testbed environment and provide experimental results showcasing a lossless streaming video session handover between a laptop and a pDA using mobility and sensor-driven orientation triggers. Moreover, we empirically evaluate and analyze the performance of our prototype. We position our work and implementation within the Ambient Networks architecture and common prototype, centring in particular on the use of policies to steer operation. Finally, we outline current and future work items.

关键词： Triggering Mobility Management Mobile Networks Handover Cross-Layer Information Management

Use and Attitudes towards Teleconsultation in Dentistry

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

E-Health Telecommunication Systems and Networks 2013年第1期2卷 9-12页

作者： Eino Ignatius K.makela Seinajoki Central Hospital SeinajokiFinland Tampere University of Technology TampereFinland

An electronic (web-based) questionnaire was devised to find out the extent of teleconsultation and e-mail use for patient-provided communications in dentistry. This project was carried out in 2011 inthe health care district of South-Ostrobothnia, in South-Western *** questionnaire was sent by e-mail to all 120 regional dentists, to which 76 replies were obtained (response rate 63%). The responses indicated a surprisingly positive attitude towards teleconsultation. A clear majority of 91% indicated that it could bring additional benefits to the current consultation *** study revealed that a slight majority of dentists in the region use e-mail for patient communication and 53% used e-mail for consultation. Approximately 10% use videoconferencing for *** study also revealed that the majority of those who do not yet use electronic consultation are willing to try them out in the future. Security issues are a concern for many dentists. practically all respondents wish for written instructions on the use of electronic consultation.

关键词： Teledentistry Teleconsultation E-Mail patient-provider Communication Computer-Assisted Dentistry

Enhanced Map-Based Indoor Navigation System of a Humanoid Robot Using Ultrasound Measurements

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Intelligent Control and Automation 2012年第2期3卷 111-116页

作者： Iivari Back Jouko Kallio Kari makela Department of Biomedical Engineering Tampere University of TechnologySeinajokiFinland

During recent years, walking humanoid robots have gained popularity from wheeled vehicle robots in various assistive roles in human’s environment. Self-localization is a necessary requirement for the humanoid robots used in most of the assistive tasks. This is because the robots have to be able to locate themselves in their environment in order to accomplish their tasks. In addition, autonomous navigation of walking robots to the pre-defined destination is equally important mission, and therefore it is required that the robot knows its initiate location precisely. The indoor navigation is based on the map of the environment used by the robot. Assuming that the walking robot is capable of locating itself based on its initiate location and the distance walked from it, there are still factors that impair the map-based navigation. One of them is the robot’s limited ability to keep its direction when it is walking, which means that the robot is not able to walk directly from one point to another due to a stochastic error in walking direction. In this paper we present an algorithm for straightening the walking path using distance measurements by built-in sonar sensors of a NAO humanoid robot. The proposed algorithm enables the robot to walk directly from one point to another, which enables precise map-based indoor navigation.

关键词： Indoor Navigation Humanoid Robot Service Robot

Technology for Elderly with Memory Impairment and Wandering Risk

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

E-Health Telecommunication Systems and Networks 2013年第1期2卷 13-22页

作者： Sami perala Kari makela Anna Salmenaho Rami Latvala South Ostrobothnia Health Care District SeinajokiFinland South Ostrobothnia Health Technology Development Centre SeinajokiFinland Tampere University of Technology SeinajokiFinland

Objective:The main objective of this project was to studyhow to secure the wandering of elderly persons diagnosed with dementia caused by Alzheimer’s disease by using healthcare technologies. Methods:The study was carried out during a three-year period (2008-2011) in the region of South Ostrobothnia, Finland. Thirty-two elderly persons living at home and diagnosed with Alzheimer’s disease participated in the study. The ages of the intervention group ranged from 66 to 90 years;the average age was 81 years. A total of 63 different home care devices including 24 location based technologies were tested during the *** choice of technology used was based on the individual needs of the elderly person. Results:participants with mild stage memory impairment were able to use and benefit from the technology installed during the intervention to live more *** most useful devices were those that operated within the home. Nine of ten users of door alarm systems, five of nine users of GpS systems and all users of GSM systems were satisfied with the technologies. Conclusions:Location based alarm and access control technology can have a positive impact on the lives of elderly persons suffering from dementia. When chosen appropriately, technology can help to reduce or eliminate the wandering often associated with *** of the technology used, it should be installed when the elderly person is at the early stages of dementia;at later stages of the disease it is usually impossible for the elderly to adequately adopt the device.

关键词： Healthcare Technology Home Care Gerontechnology Wandering Dementia Alarm Systems