Explicit and tacit knowledge in construction of passive housing, knowledge models in Lithuania / Išreikštinės ir neišreikštinės žinios pasyviųjų namų statyboje, žinių modeliai pasaulyje ir Lietuvoje

Optimization of building maintenance expenditure becomes really an urgent issue in Lithuania. People prefer a warmer housing and show interest in recent decisions of engineering systems. They are looking for the best decision of heating costs optimization to price down heating costs not 10-20%, but a number of times. The results of passive houses scientific research as well as models of passive housing are discussed in the article. They ascertain and compare features of passive housing construction in different countries which depends on climatic conditions. Most countries support traditional housing. Remarkable thermal resistance and cost efficient maintenance of passive housing may be reached through an integrated approach of using proper architectural, constructional and engineering resolution, as well as applying the most relevant material usage and elaborating and accumulating practical knowledge. Lithuania, as well as other countries in the world, reveals that the concept of tacit knowledge still lacks sufficient attention within the construction industry, despite the fact that proper understanding and management of this resource is of immense importance for the achievement of better organizational performance. As the initial step towards the management of tacit knowledge, this paper examines the factors affecting tacit knowledge generation and utilization in the construction industry. Santrauka Lietuvoje ypač aktualus tampa pastato eksploatacinių išlaidų optimizavimas. Žmonės renkasi šiltesnį būstą, domisi naujausiais inžinerinių sistemų sprendimais. Išlaidų šildymui sumažinti ne 10–20 %, bet bent kelis kartus, ieškomas geriausias šildymo išlaidų optimizavimo būdas. Straipsnyje aptarti pasaulyje atlikti pasyvaus būsto moksliniai tyrimai, bei pasyvaus namo modeliai. Išaiškinti ir palyginti įvairių šalių pasyvių namų statybos ypatumai, priklausomai nuo klimato sąlygų. Daugelyje šalių yra palaikomos ankstesnės statybų tradicijos. Puikių pasyviojo namo šiluminės varžos ir ekonomiškumo rezultatų galima pasiekti kompleksiškai taikant optimalius architektūrinius, statybinius ir inžinerinius sprendimus, siekti geresnių medžiagų panaudojimo, tobulinti ir kaupti praktikos įgūdžius statyboje. Jei rinkos sąlygos leidžia, turimas žinias reikia struktūrinti. Pastebima, kad Lietuvoje ir pasaulyje statybos pramonės viduje išreikštinių ir neišreikštinių žinių sąvokos vis dar stokoja pakankamo dėmesio, neatsižvelgiant į tai, kad tinkamas supratimas ir turimų išteklių vadyba turi didžiulę reikšmę siekiant geresnių tendencijų projektavime, o taip pat neišreikštų žinių generavime ir panaudojime statyboje. Raktiniai žodžiai: pasyvusis būstas, išreikštinės žinios, neišreikštinės žinios, energijos taupyma

Contamination Status of Well Water around Nawinna Dumping Site, Maharagama

Waste generation by man started since the beginning of civilization as a consequence ofhuman activities, involving the production of goods and services and the consumption ofnatural sources. Garbage dumping is a global environment issue. Ground water is one of themain victims of garbage dumping. The major danger associated with drinking water sourcesis the possibility of its recent contamination by sewage or human and animal excreta.Another problem is siting of a drinking water system (wells and boreholes) near a refusedumpsite or landfill. When aquifer from which the well draws water is contaminated orcontaminated surface water enters the well, well water can be contaminated.Nawinna area which is located in Maharagama contained a major solid waste dumping site.Eighty wells were sampled monthly from January 2012 to October 2012. Water samples werecollected in sterilized glass bottles using standard methods both for microbial and physicochemicaltests. Microbiological and physico-chemical parameters were measured using thestandard methods and Principal Component Analysis (PCA) was carried out to evaluate therelative water quality among GN divisions around dumping site.Results showed that both total and fecal coliform counts ranged between 0 to >1,100 countsper 100 ml and almost all tested wells were significantly contaminated with total and fecalcoliform (p<0.001), sometimes exceeding 1,100/100 ml. The total nitrate concentration wassignificantly high (p<0.001) exceeding more than 60 mg/l. The first study, reported in 2007in the same study area found that Nitrate concentration was exceeding 40mg/l and the secondrepeated study in the same area in 2011 was detected 50 mg/lof nitrate. Therefore, theremight be a significant tendency of increasing the nitrate concentration in well water in thearea. Mean ranges of physico-chemical parameters of pH (4.11-7.14), Nitrate (0.64-77.31mg/l), Conductivity (114-70,000 μS cm-1), Biological Oxygen Demand (BOD) (0.03-19.40mg/l), Phosphate (0.07-2.68 mg/l) and Chemical Oxygen demand (COD) (0.14-64.13 mg/l)detected respectively. Nitrate concentration has a significant correlation with ChemicalOxygen Demand (COD). Principal component analysis revealed that the Wattegedara GNdivision contained the highest polluted wells. According to the questionnaire survey, peopleof the area are complaining about the deterioration status of water quality with odour, tasteand colour. It was found that some wells within the study area were acidic (pH 4.11).As a conclusion, total coliform, fecal coliform, nitrate, phosphate, COD, BOD andconductivity values were exceeded than the drinking water quality standards given by SLS.This may due to excessive application of organic and inorganic fertilizers in homegardens,unregulated garbage dumping, too much closer toilet pits, limited space for constructinghouses, and lack of restrictions. The presence of coliform bacteria can indicate the possible presence of pathogens and other pollutants. It is important to highlight that the study area hasa very shallow water table and susceptible to spread of pollutant and microbes which effecton human health within very short period and this situation becomes worse in near future.

Prestress evaluation in prestressed concrete plate-like structures

Condition assessment and capacity evaluation of existing structures using their vibration responses has been subjected to extensive research for many years. Prestressed concrete structures have been one of the main focuses of those studies. In the case of prestressed concrete structures, effective prestress force is the most important parameter for their best performance and yet currently there is no effective method in identifying the prestressing force in an existing prestressed concrete structure. Effect of prestress is different for different types of structural elements and has to be treated accordingly for its accurate quantification. This paper presents a new approach to evaluate the effective prestress force of plate-like structures with simply supported boundary conditions using their vibration responses. The proposed method quantifies the prestress effect with a reasonable good accuracy, even with noisy measurements using both periodic and impulsive excitations. Prestress estimation can be done using collected data from as less as two measurement locations

Group B streptococcal infective endocarditis in a young non-pregnant female with rheumatic heart disease - A Case Report

Group B Streptococcus (GBS) is a rare cause of infective endocarditis in adults associated with a high mortality rate due to the frequent occurrence of local and systemic complications. Here we report a case of infective endocarditis (IE) in a young non-pregnant female with a history of rheumatic heart disease (RHD) who presented with a short history of fever, shortness of breath and constitutional symptoms. GBS was isolated from a single blood culture along with echocardiographic findings of a cardiac vegetation and ophthalmologic findings of a Roth spot. Based on the Modified Duke Criteria, a definitive diagnosis of infective endocarditis was made. She was treated with a prolonged course of intravenous (IV) ceftriaxone, with gentamicin being added to the regimen, following which she made a complete recovery.</p

Development and validation of a reference marker for identification of aerobic and anaerobic bacteria associated with diabetes chronic wound ulcers using PCR denaturing gradient gel electrophoresis

Introduction: Diabetes chronic wounds consist with a diverse microbial community and unculturablespecies may be highly prevalent.Objectives: This study aimed to establish a bacterial reference marker consisting of a group ofchronic wound related bacteria, using polymerase chain reaction-denaturing gradient gelelectrophoresis (PCR-DGGE) for profiling of bacteria in diabetes chronic wound infections.Methods: DNA was extracted from the known wound bacterial strains. PCR–DGGE was performedusing eubacterial specific primers targeting V2-V3 region of 16S rDNA. DGGE was performed usinga 30-55% denaturing gradient. Migration position of each organism was detected on DGGE gel andimportant organisms were selected. Equal volume from PCR products of each selected organism wasmixed, diluted with gel loading dye in 1:1.5 ratio and used for all DGGE gels. The ladder was thensubjected to species identification of fifteen tissue debridement specimens obtained from diabeteschronic wound ulcers. The identification efficacy was tested by sequencing.Results: DNA of bacterial pathogens which showed different migration distances on the gel werecombined and used as a reference panel. This bacterial ladder consisted of eleven different bacterialspecies including Bacteroides sp., S. aureus, Acineto bacter sp., P. aeruginosa, Streptococcus Group Aand Group B sp., E. faecalis, Providencia sp., Veillonella sp., E .coli and Enterobacter sp. Accordingto the reference panel, Pseudomonas species were abundant. Further the results were confirmed bysequencing.Conclusion: Reference marker allows comparative analysis of DGGE patterns and can be used as atool for presumptive identification of polymicrobial microbiota in chronic wound infections

Establishing Campylobacter culture methods in a clinical diagnostic laboratory and the first report of Campylobacter species isolation in northern Sri Lanka

Introduction: The Enteric Reference Laboratory of the Medical Research Institute (ERL/MRI), Colombo is the only public sector laboratory in Sri Lanka that performs Campylobacter cultures. Due to logistic limitations involving specimen transport from distant sites, efforts were taken to establish Campylobacter culture facilities in our local clinical microbiology laboratory.Methods: A blood-free charcoal-based selective agar medium (Karmali medium) was chosen based on performance characteristics and quality control (QC)/verification performed at the ERL/MRI. A suitable incubating method was assessed and chosen, and QC was performed in our laboratory. A technical staff member of our local laboratory received capacity building training at the ERL/MRI.Results: The quality control/verification process of the Karmali medium was satisfactory. The variable atmospheric incubator was chosen as the incubating method as it was shown to be more economical in the long-term given the anticipated work load and the QC was satisfactory. Following a satisfactory verification process, Campylobacter culture method was introduced in our laboratory. Five C. jejuni and one hippurate-negative C. jejuni/C. coli was detected in faecal specimens of six paediatric patients between May-December 2018. The isolation rate was 2.25% (6/267). Ciprofloxacin resistance was detected in four out of five C. jejuni isolates.Conclusion: Establishing Campylobacter culture methods in a routine clinical diagnostic laboratory will be beneficial in regions with high prevalence of diarrhoeal disease and with logistic limitations for specimen transport to the central reference laboratory. This is the first report of isolation and antimicrobial susceptibility of Campylobacter species from patients in northern Sri Lanka.</p