Construction risk assessment is the final and decisive stage of risk analysis. When highly changeable conditions of works execution are predicted, risk should be evaluated in the favorable, moderate, and difficult random conditions of construction. Given the random conditions, the schedule and cost estimate of the construction are developed. Based on these values, the risk of final deadline delay and the risk of total cost increase of construction completion are calculated. Next, the charts of the risks are elaborated. Risk changes are shown in the charts and are analyzed in the range [1, 0].
The paper presents an approach to evaluating a building throughout its whole life cycle in relation to its sustainable development. It describes basic tools and techniques of evaluating and analysing the costs in the whole life cycle of the building, such as Life Cycle Assessment, Life Cycle Management, Life Cycle Cost and Social Life Cycle Assessment. The aim of the paper is to propose a model of cost evaluation throughout the building life cycle. The model is based on the fuzzy sets theory which allows the calculations to include the risks associated with the sustainable development, with the management of the investment and with social costs. Costs incurred in the subsequent phases of the building life cycle are analysed and modelled separately by means of a membership function. However, the effect of the analysis is a global cost evaluation for the whole life cycle of the building.
These joints are used when the designer and contractor anticipate difficulties during the construction of overlap joints. They were not included in the PN EN 1993‒1‒8 in full scale. Resistance assessment of such joints is presented in accordance with standard rules. The results were compared with the experimental studies carried out at the “Mostostal” Centre; while the former research activities and the legitimacy of the proposed method of assessing the resistance of these joints was confirmed. This is an example of an overlap joint calculation.
For the use of acoustic assessment of machinery, a global index of acoustic quality has been developed. Acoustic quality index is considered as a product of the following partial indices: sound power index, index of distance between the workstation and the machine, radiation directivity index, impulse and impact noise index and noise spectrum index. Each partial index always assumes positive value. If the value of global index does not exceed 1, the noise of the assessed machine will not exceed the admissible value of A-weighted sound pressure level at the workstation.
Experimental tests were carried out in order to determine the values of global indices for a group of engine-generators, with the use of inversion method allowing for the determination of sound power level. The correctness of the determined values of indices was confirmed by the results of A-weighted sound pressure level measurements, at the hypothetically assumed workstations in simulated in situ conditions.
A dynamic economy contributes to the increase in the number of workers exposed to mechanical vibration caused by machines and transport equipment. As the means of transport are insufficiently recognised sources of mechanical vibrations, this article presents the results of whole-body and hand-arm vibration tests of 30 most common means of in-house transport. An analysis of vibration signals recorded at each workstation according to PN-EN 14253 and PN-EN ISO 5349 made it possible to determine the weighted values of components of directional vibration acceleration and the values of daily vibration exposure A(8).
In order to assess exposure to whole-body and hand-arm vibration at the tested workstations of in-house transport, indices of vibration hazard related to admissible values, the total evaluation index (developed in a previous study at CIOP-PIB) and a three-degrees scale for assessing exposure to vibrations were used. The assessment showed that the workstations were a major hazard. Vibration hazards at all those workstations were classified as either medium or high.
This paper addresses the issue of antibacterial drugs, estrogens and cytostatic drugs’ presence in
surface waters and their influence on animals. The ecotoxicity and the impact of three active compounds: ciprofloxacin, 17α-ethinylestradiol and 5-fluorouracil on protozoa, crustaceans and fish were examined. Acute
tests (crustaceans’ immobilization test, fish survival test, enzymatic test on Daphnia magna) and chronic tests
(growth test on protozoa, reproduction test on crustaceans and juvenile growth test on two species of fish) were
performed. Acute toxicity studies revealed diversified species - sensitivity to the tested compounds. Crustaceans Artemia salina were the most resistant to all three pharmaceuticals. Fish also demonstrated low sensitivity
to ciprofloxacin and 5-fluorouracil (LC(EC)50-96h > 100 mg/l). In the survival tests, the greatest harm in respect
to fish and crustaceans was demonstrated by 17α-ethinylestradiol, and in the enzymatic tests - by ciprofloxacin.
In all chronic tests, the toxic effects of drugs were proven. Tested compounds limited reproduction of crustaceans and growth of protozoa and fry. The risk assessment, conducted on the basis of the PEC/PNEC quotient,
showed a significant risk in relation to aquatic animals caused by the presence of 17α-ethinylestradiol and
5-fluorouracil in concentrations detected in surface waters.
In the paper toxicity assessment of hospital wastewaters samples was performed using direct-contact
tests consisting of five species, which represent three different trophic levels of the food chain. IC50 or EC50 values were estimated for each tested organism: Pseudokirchneriella subcapitata IC50/72h 18.77%, Daphnia magna
EC50/48h 20.76%, Thamnocephalus platyurus EC50/24h 22.62%, Artemia salina EC50/24h 59.87% and Vibrio fisheri
EC50/15min 46.17%. Toxic potential of hospital wastewater was described using a system of wastewater toxicity
classification. The toxic units (TU) values estimated for each test indicate that hospital wastewaters are toxic
(Class III). The variable results of the tests’ sensitivity confirmed the need of application of microbiotests battery with organisms of different trophic levels.
The paper presents a new method of lifetime calculations of steam turbine components operating at high temperatures. Component life is assessed on the basis of creep-fatigue damage calculated using long-term operating data covering the whole operating period instead of representative events only. The data are analysed automatically by a dedicated computer program developed to handle big amount of process data. Lifetime calculations are based on temperature and stress analyses performed by means of finite element method and using automatically generated input files with thermal and mechanical boundary conditions. The advanced lifetime assessment method is illustrated by an example of lifetime calculations of a steam turbine rotor.
Although the usefulness of alternative assessment in second language (L2) classrooms has been extensively recognized by scholars, the use of the various types of alternative assessment in English as a Foreign Language (EFL) contexts has not received adequate attention by L2 practitioners. To contribute to this line of research, the present research sought to examine the impact of a portfolio-based writing instruction on writing performance and writing anxiety of EFL students. To this end, a number of 41 EFL learners were recruited as the participants of this study. They were then randomly divided to an experimental group (N=21) and a control group (N=20). The participants in the experimental group received portfolio-based writing instruction, whereas the control group received the regular writing instruction with no archiving of students’ drafts in portfolios. Timed-writing tasks and the Second Language Writing Anxiety Inventory (SLWAI) were employed to collect the data. The results obtained from ANCOVA analysis revealed that the portfolio-based writing instruction aided the participants in improving their writing performance more than the control group. Moreover, it was found that the use of portfolios significantly reduced the L2 writing anxiety of the participants while the traditional writing instruction did not have any significant impact on L2 writing anxiety of the control group. The pedagogical implications for portfolio-based writing instruction are discussed finally.
The article discusses "Rules for using the point rating scales for assessing the technical condition and usability of road engineering objects – second edition", which were introduced by the General Directorate for National Roads and Motorways (GDDKiA) Regulation No. 1/2019. The main objective of "Rules..." was to standardize the method of point rating assessment of technical condition and usability, and in the second edition, to take into account the latest construction and material solutions. Because the results of inspections are analyzed and compared not only at the regional but also at the national level, it is very important for all inspectors in the country to evaluate the technical condition and usability in an analogous manner. While developing the 2nd edition, the authors maintained the assumptions of continuity of inspection system, including adaptation to the inspection manuals, algorithms, and software supporting the management of bridges.
Currently available field rock mass deformability determination methods are rather difficult to perform, due to their complexity and a time-consuming nature. This article shows results of a suitability assessment of a Pen206 borehole jack (a hydraulic penetrometer) for field rock mass deformability measurements. This type of the borehole jack is widely used in Polish hard coal mining industry. It was originally intended only for quick rock mass strength parameters determination. This article describes an analysis and scope of basic modifications performed mainly on a borehole jack head. It includes discussion of results with possible directions for future development of the device.
Canal connecting Elbląg with Ostróda was built in the XIX century to transport corn to the port of Elbląg. Due to economic and political changes it never played its economic function. Now it is a tourist attraction. The canal is thus of some tourist value which is difficult to assess. Tourist value of the Elbląg Canal was assessed with the travel cost method (TCM) within the study carried out in 2003. The study allowed for estimating the object’s value based on its usefulness expressed by inclination to payment. Three groups of users were distinguished when analysing the demand for recreational canal’s services: tourists using ships of the Elbląg–Ostróda Navigation Company, individual sailors and anglers. Total tourist value of the canal calculated as NPV of the annual value of canal’s services depends on adopted interest rate. At a rate of 3.2% the value is 328 thous. PLN (73.9 thous. euro), at a rate of 4% – 282 thous. PLN (63.5 thous. euro), while at 8% interest rate it decreases to 160 thous. PLN (36.0 thous. euro).
The article presents the methodology for selecting the optimal variant of the road on a regional level. The suggested methodology is based on a combination of criteria value normalization method and the variant assessment method. Based on survey studies conducted using the Delphi method, a starting list of criteria was designed and the significance of the individual groups of main criteria and sub-criteria was determined. The final assessments of the analysed variants are calculated based on the aggregation of the marks obtained for the normalization and assessment methods. The methodology can be divided into six stages: determining the variants for analysis, selecting the variant assessment criteria, creating the assessment matrix, normalizing criteria value, using the variant assessment method, variant ranking. The methodology was tested on the examples of planning a bypass of Mazury and Księżyno towns as a part of Regional Road 678 in Poland.