Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

English (EN)·Polski (PL)·Yкраїнський (UK)
Przejdź do strony domowej biblioteki Centralna Biblioteka Wojskowa Link otwiera się w nowym oknie Logo biblioteki Prolib Integro - strona głównaCentralna Biblioteka Wojskowa

Wyszukujesz frazę "(J.P.)." wg kryterium: Autor

  Lista filtrów
Wyrównaj
Wyświetlanie 1-15 z 775
Tytuł:
Analysis of SQL Injection Detection Techniques
Autorzy:
Singh, J. P.
Powiązania:
https://bibliotekanauki.pl/articles/375681.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
SQL Injection
runtime monitoring
Static Analysis
Opis:
SQL Injection is one of the vulnerabilities in OWASP's Top Ten List forWeb Based Application Exploitation. These type of attacks take place on Dynamic Web applications as they interact with databases for various operations. Current Content Management System like Drupal, Joomla or Wordpress have all information stored in their databases. A single intrusion into these type of websites can lead to overall control of websites by an attacker. Researchers are aware of basic SQL Injection attacks, but there are numerous SQL Injection attacks which are yet to be prevented and detected. Over here, we present the extensive review for the Advanced SQL Injection attack such as Fast Flux SQL Injection, Compounded SQL Injection and Deep Blind SQL Injection. We also analyze the detection and prevention using the classical methods as well as modern approaches. We will be discussing the Comparative Evaluation for prevention of SQL Injection.
Źródło:
Theoretical and Applied Informatics; 2016, 28, 1-2; 37-55
1896-5334
Pojawia się w:
Theoretical and Applied Informatics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Internet jako źródło postaw prospołecznych
Internet as a Source of Pro−Social Attitudes
Autorzy:
Bierówka, J. P.
Powiązania:
https://bibliotekanauki.pl/articles/2137814.pdf
Data publikacji:
2007
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Internet
information society
reciprocity principle
communitas
common good
pro−social attitude
społeczeństwo informacyjne
zasada wzajemności
dobro wspólne
postawa prospołeczna
Opis:
The article aims at verification of the following thesis: the Internet as a platform of new interpersonal relationships promotes pro-social attitudes. They find their expression in various initiatives undertaken selflessly by individuals in order to actualise the common good (e.g. Linux, Wikipedia, support groups, knowledge-exchange portals, etc). Authoress' own research has been used for exemplification purposes. It has been assumed that human inclination to reciprocity constitutes, among others, a source of pro-social attitudes. This inclination can be more or less efficiently actualized, depending on the structure of human relations. The significance of reciprocity increases when the role of institutionalism, formalism and centralisation decreases. Nowadays, the patterns of social relations are subject to profound transformations primarily as a result of the development of the Internet. New social relations are more reciprocal in character. The Internet creates new communication space in which social or even pro-social nature of people can be fruitfully actualised.
W artykule podjęto próbę weryfikacji następującej hipotezy: Internet, stając się platformą nowych struktur relacji międzyludzkich, przyczynia się do rozpowszechniania postaw prospołecznych. Ich wyrazem są różnego rodzaju inicjatywy podejmowane bezinteresownie przez jednostki w celu realizowania dobra wspólnego (np. Linux, Wikipedia, grupy samopomocowe, portale wymiany wiedzy itp.). Odniesiono się tu głównie do źródeł zastanych, natomiast w celach egzemplifikacyjnych wykorzystane zostały badania własne. Weryfikując hipotezę – odwołując się do klasycznych i współczesnych teorii socjologicznych – przyjęto, że źródłem postaw prospołecznych człowieka jest między innymi jego skłonność do wzajemności. Cecha ta może być bardziej lub mniej skutecznie realizowana, w zależności od charakteru struktury międzyludzkich relacji. Znaczenie wzajemności wzrasta, gdy maleje w nich rola instytucjonalizacji, formalizacji i centralizacji. Wzory relacji społecznych ulegają obecnie gruntownym przemianom, przede wszystkim pod wpływem rozwoju Internetu. W nowej formie nie tylko sprzyjają one, ale nawet wymuszają zwrotny charakter relacji. Internet tworzy więc nową przestrzeń komunikacyjną, w której owocnie może realizować się społeczna czy wręcz prospołeczna natura człowieka.
Źródło:
Studia Socjologiczne; 2007, 3(186); 15-36
0039-3371
Pojawia się w:
Studia Socjologiczne
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Durability and narrow pore size distribution (PSD) of carbons fabricated from Salix Viminalis wood
Autorzy:
Łukaszewicz, J.P.
Zieliński, K.
Powiązania:
https://bibliotekanauki.pl/articles/184999.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
węgiel drzewny
Salix viminalis
wooden charcoal
carbon molecular sieves
specific surface
pore structure
Opis:
Microporous carbon molecular sieves of extremely narrow pore size distribution were obtained by carbonization of a novel raw material (Salix viminalis). The precursor is inexpensive and widely accessible. The pore capacity and specific surface area are upgradable by H3PO4 treatment without significant change of narrowed PSD. The dominating pore size indicates that these molecular sieves are a potential competitor to other nanoporous materials such as opened and purified carbon nanotubes.
Źródło:
Chemical and Process Engineering; 2011, 32, 3; 195-201
0208-6425
2300-1925
Pojawia się w:
Chemical and Process Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Recognizing Sharp Features of 2-D Shapes
Autorzy:
Gewali, L.
Scanlan, J. P.
Powiązania:
https://bibliotekanauki.pl/articles/226950.pdf
Data publikacji:
2010
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
shape recognition
shape similarity
boundary approximation
shape decomposition
shape simplification
Opis:
We present an efficient algorithm for recognizing and extracting sharp-features from complex polygonal shapes. The algorithm executes in O(n²) time, where n is the number of vertices in the polygon. Sharp-feature extraction algorithms can be useful as a pre-processing step for measuring shape-similarity between polygonal shapes.
Źródło:
International Journal of Electronics and Telecommunications; 2010, 56, 2; 153-156
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Automotive fleet repair facility wastewater treatment using air/ZVI and air/ZVI/H2O2 processes
Oczyszczanie ścieków z zakładów naprawczych floty samochodowej z wykorzystaniem procesów powietrze/ZVI i powietrze/ZVI/H2O2
Autorzy:
Bogacki, J. P.
Al-Hazmi, H.
Powiązania:
https://bibliotekanauki.pl/articles/205311.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
wastewater treatment
zero-valent iron
advanced oxidation processes
AOP
ZVI
oczyszczanie ścieków
żelazo metaliczne
zaawansowane procesy utleniania
Opis:
Advanced automotive fleet repair facility wastewater treatment was investigated with Zero-Valent Iron/Hydrogen Peroxide (Air/ZVI/H2O2) process for different process parameters: ZVI and H2O2 doses, time, pH. The highest Chemical Oxygen Demand (COD) removal efficiency, 76%, was achieved for ZVI/H2O2 doses 4000/1900 mg/L, 120 min process time, pH 3.0. COD decreased from 933 to 227 mg/L. In optimal process conditions odor and color were also completely removed. COD removal efficiency was increasing with ZVI dose. Change pH value below and over 3.0 causes a rapid decrease in the treatment effectiveness. The Air/ZVI/H2O2 process kinetics can be described as d[COD]/dt = -a [COD]tm, where ‘t’ corresponds with time and ‘a’ and ‘m’ are constants that depend on the initial reagent concentrations. H2O2 influence on process effect was assessed. COD removal could be up to 40% (560 mg/L) for Air/ZVI process. The FeCl3 coagulation effect was also evaluated. The best coagulation results were obtained for 700 mg/L Fe3+ dose, that was slightly higher than dissolved Fe used in ZVI/H2O2 process. COD was decreased to 509 mg/L.
Ścieki z zakładu naprawczego floty samochodowej poddano oczyszczaniu z wykorzystaniem żelaza metalicznego i nadtlenku wodoru (Air/ZVI/H2O2). Badano wpływ dawki żelaza i nadtlenku wodoru, czasu i pH na efektywność procesu. Największy stopień usunięcia ChZT, 76%, uzyskano dla dawek ZVI/H2O2 4000/1900 mg/L, czasu 120 min i pH 3.0. ChZT zmniejszono z 933 do 227 mg/L. Dodatkowo uzyskano całkowite usunięcie barwy i zapachu. Skuteczność usunięcia ChZT rosła wraz ze wzrostem zastosowanej dawki ZVI. Zmiana pH na inne niż 3, powoduje gwałtowne zmniejszenie efektywności procesu. Kinetyka procesu może zostać opisana z wykorzystaniem równania d[COD]/dt = -a [COD]tm, gdzie ‘t’ oznacza czas a ‘a’ i ‘m’ są stałymi zależnymi od początkowego stężenia reagentów. Badano także wpływ H2O2 na efektywność procesu. Skuteczność usunięcia ChZT wynosi 40% (560 mg/L) w przypadku zastosowania ZVI bez dodatku H2O2. Określono także skuteczność koagulacji z wykorzystaniem FeCl3. Najlepsze rezultaty uzyskano dla dawki Fe3+ 700 mg/L, zmniejszając ChZT do 509 mg/L.
Źródło:
Archives of Environmental Protection; 2017, 43, 3; 24-31
2083-4772
2083-4810
Pojawia się w:
Archives of Environmental Protection
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Morphology of immune organs after very virulent plus strain of Marek’s disease virus infection in vaccinated hens
Autorzy:
Madej, J.P.
Wozniakowski, G.
Gawel, A.
Powiązania:
https://bibliotekanauki.pl/articles/31459.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Opis:
Marek’s disease (MD) outbreaks in poultry flocks may be associated with overriding of vaccine immune protection by very virulent (vvMDV) or very virulent plus (vv+MDV) strains. This paper presents the study on lymphoid organ morphology in the latent phase of MD caused by vv+MDV which break post-vaccinal protection in hens. We also immunohistochemically examined B and T populations as well as B/T and CD4+/CD8+ ratio of lymphocytes in lymphatic organs and, as a background, in MD lymphomas from non-lymphatic organs. The number of antigen expressed cells was evaluated as a percentage of positive cells in the one power field. Organ samples were collected from 24 dead reproductive hens (Ross 308 line) in age between 35-56 weeks, infected with vv+MDV. The hens originated from farms with MD outbreaks, despite earlier routine vaccination with CVI988/Rispens + HVT. The control organ samples originated from 15 clinically healthy hens at the same age and line, subjected to the same vaccination schedule. The number of CD3+, CD8+ and TCRγδ+ cells was significantly lower in MDV infected thymus, spleen and cecal tonsils in comparison to that found in the control organs. The proportion of CD4+ was also distinctly reduced in the thymus and limited in the spleen of MDV infected hens. This study revealed that infection with field vv+MDV isolates might break post-vaccinal protection and influence the central and peripheral immune system. The decrease in CD8+ and TCRγδ+ cell number in the thymus, spleen and cecal tonsils suggests that primarily these cells are involved in cell-mediated cytotoxicity against MDV transformed cells during latency.
Źródło:
Polish Journal of Veterinary Sciences; 2016, 19, 2
1505-1773
Pojawia się w:
Polish Journal of Veterinary Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Polyphenol composition of extract from aerial parts of Circaea lutetiana L. and its antioxidant and anti-inflammatory activity in vitro
Autorzy:
Granica, S.
Piwowarski, J.P.
Kiss, A.K.
Powiązania:
https://bibliotekanauki.pl/articles/19454.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Opis:
The chemical composition and bioactivity of a water/methanol extract prepared from aerial parts of Circaea lutetiana were determined. HPLC-DAD-MS3 analysis revealed the presence of 14 different compounds comprising phenolic acids, ellagitannins and flavonoids. Antioxidant assays showed the extract's strong scavenging activity towards DPPH (SC50 33.1±3.1 μg/ml), O2 - (SC50 4.0±2.3 μg/ml) and H2O2 (SC50 below 2 μg/ml). Enzyme-based studies revealed that Circaea lutetiana extract inhibits the activity of hyaluronidase (IC50 13.3±2.4 μg/ml) and lipoxygenase (IC50 44.7±1.4 μg/ml). These results support some traditional uses of Circaea lutetiana.
Źródło:
Acta Biologica Cracoviensia. Series Botanica; 2013, 55, 1
0001-5296
Pojawia się w:
Acta Biologica Cracoviensia. Series Botanica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Cosmetic wastewater treatment using dissolved air flotation
Oczyszczenie ścieków kosmetycznych z wykorzystaniem procesu flotacji ciśnieniowej
Autorzy:
Bogacki, J. P.
Marcinowski, P.
Naumczyk, J.
Wiliński, P.
Powiązania:
https://bibliotekanauki.pl/articles/205185.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
wastewater treatment
GC-MS
gas chromatography
cosmetic wastewater
dissolved air flotation
PPCPs
pharmaceutical and personal care pollutants
oczyszczanie ścieków
chromatografia gazowa
ścieki kosmetyczne
flotacja ciśnieniowa
Opis:
Five cosmetics wastewater samples were treated by Dissolved Air Flotation (DAF) assisted by coagulation. Different aluminum based coagulants were used: (Al2(SO4)3, Al 1019, Al 3010, Al 3030, Al 3035, PAX 16 and PAX 19). The raw wastewater COD values were in the range 285–2124 mg/l. The efficiency of DAF depended on different coagulants and production profile of factory. COD removal was varied from 11.1 to 77.7%. The efficiency of coagulants was similar during treatment of particular sample. The best results were obtained with Al2(SO4)3 and for sample 5 – lotions and shampoos production. The wastewater from UV filter creams production (sample 4) was resistant to treatment by DAF regardless of used coagulant. HS-SPME-GC-MS analysis can be a confirmation of DAF effectiveness.
Pięć próbek ścieków kosmetycznych zostało poddanych oczyszczaniu z wykorzystaniem flotacji ciśnieniowej wspomaganej koagulacją. Stosowano różne koagulanty na bazie glinu: Al2(SO4)3, Al 1019, Al 3010, Al 3030, Al 3035, PAX 16 and PAX 19. Wartość ChZT ścieków surowych była w zakresie 285–2124 mg/l. Skuteczność procesu flotacji ciśnieniowej była zależna od zastosowanego koagulantu i profilu produkcji fabryki kosmetyków. Skuteczność usunięcia wartości ChZT była w przedziale 11,1–77,7%. Skuteczność wszystkich koagulantów podczas oczyszczania każdej z próbek ścieków była podobna. Najlepsze rezultaty uzyskano z wykorzystaniem koagulantu Al2(SO4)3 , dla próbki 5 – ścieki pochodzące z produkcji szamponów i logionów. Ścieki z produkcji kremów z filtrem UV (próbka 4) były oporne na oczyszczanie za pomocą procesu flotacji ciśnieniowej, niezależnie od zastosowanego koagulantu. Zastosowana analiza HS-SPME-GC-MS potwierdziła skuteczność oczyszczania z wykorzystaniem flotacji ciśnieniowej.
Źródło:
Archives of Environmental Protection; 2017, 43, 2; 65-73
2083-4772
2083-4810
Pojawia się w:
Archives of Environmental Protection
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Recovery of Pig Iron from Copper Smelting Slag by Reduction Smelting
Autorzy:
Erdenebold, U.
Choi, M.-H.
Wang, J.-P.
Powiązania:
https://bibliotekanauki.pl/articles/355067.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
copper slag
reduction
pig iron
fayalite
recovery
Opis:
Copper slag is a by-product obtained during smelting and refining of copper. Copper smelting slag typically contains about 1 wt.% copper and 40 wt.% iron depending upon the initial ore quality and the furnace type. Main components of copper slag are iron oxide and silica. These exist in copper slag mainly in the form of fayalite (2FeO ·SiO2 ). This study was intended to recover pig iron from the copper smelting slag by reduction smelting method. At the reaction temperature of below 1400°С the whole copper smelting slag was not smelted, and some agglomerated, showing a mass in a sponge form. The recovery behavior of pig iron from copper smelting slag increases with increasing smelting temperature and duration. The recovery rate of pig iron varied greatly depending on the reaction temperature.
Źródło:
Archives of Metallurgy and Materials; 2018, 63, 4; 1793-1798
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Evaluation of two alternative procedures for measuring airflow resistance of sound absorbing materials
Autorzy:
del Rey, R.
Alba, J.
Arenas, J. P.
Ramis, J.
Powiązania:
https://bibliotekanauki.pl/articles/176777.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
material characterization
airflow resistance
sound absorbing materials
eco-friendly material
Opis:
It is well known that sound absorption and sound transmission properties of open porous materials are highly dependent on their airflow resistance values. Low values of airflow resistance indicate little resistance for air streaming through the porous material and high values are a sign that most of the pores inside the material are closed. The laboratory procedures for measuring airflow resistance have been stan- dardized by several organizations, including ISO and ASTM for both alternate flow and continuous flow. However, practical implementation of these standardized methods could be both complex and expensive. In this work, two indirect alternative measurement procedures were compared against the alternate flow standardized technique. The techniques were tested using three families of eco-friendly sound absorbent materials: recycled polyurethane foams, coconut natural fibres, and recycled polyester fibres. It is found that the values of airflow resistance measured using both alternative methods are very similar. There is also a good correlation between the values obtained through alternative and standardized methods.
Źródło:
Archives of Acoustics; 2013, 38, 4; 547-554
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An immunohistochemical analysis of lymphocytic infiltrations in canine skin cancers
Autorzy:
Madej, J.A.
Madej, J.P.
Dzimira, S.
Nowak, M.
Powiązania:
https://bibliotekanauki.pl/articles/31669.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Opis:
Lymphocytic infiltrations located in the extracellular matrix often accompany canine skin cancer. They can be characterised as an inflammatory infiltration and/or a second tumour – lymphoma. The aim of this study was an immunohistochemical analysis of a lymphocytic infiltration which accompanies spontaneous skin cancer. Twenty basal cell carcinoma, 20 non-keratinizing squamous cell carcinoma, 20 keratinizing squamous cell carcinoma and 8 sebaceous gland carcinoma samples which were accompanied by a lymphocytic infiltration and/or secondary lymphatic follicles were verified histopathologically. The expression of bcl-2, CD3, CD79α, Ki-67, MCM-3 and MCM-7 in the lymphocytic infiltration was evaluated. Four types of lymphocytic infiltrations were found: I – diffuse bcl-2⁺, II – diffuse bcl-2⁻, III – follicular bcl-2⁺/⁻ where the centre was bcl-2⁻, and the marginal zone of the follicles and the extrafollicular area were bcl-2⁺ and IV – aggregated bcl-2⁺, where the centre and periphery were bcl-2⁺. The I and IV type corresponds to lymphoma, II type is non-neoplastic immune response and III type suggest reactive follicular hyperplasia. The proliferation of lymphocytes which demonstrated the expression of neoplastic markers (I and IV), suggests preneoplastic phase (pseudolymphoma) or lymphoma – the second independent tumour. A high proliferative index of the follicular blc-2⁺/⁻ follicular infiltration indicates an increased immunological response of the host against skin cancer.
Źródło:
Polish Journal of Veterinary Sciences; 2017, 20, 1
1505-1773
Pojawia się w:
Polish Journal of Veterinary Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Noise Monitoring Networks as Tools for Smart City Decision-Making
Autorzy:
Sánchez-Sánchez, R.
Fortes-Garrido, J. C.
Bolívar, J. P.
Powiązania:
https://bibliotekanauki.pl/articles/177038.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
traffic noise
noise monitoring networks
smart city
pavement
Opis:
Noise Monitoring Networks (NMNs) have been implemented in many cities by town councils, allowing them to know, in real time, the environmental noise levels in the busiest streets by the continuous measurement of selected acoustic parameters throughout the year. NMNs are aimed at: 1) detecting areas of the city that breach guidelines for acoustic quality objectives; 2) obtaining noise data needed to develop and implement action plans; and 3) informing the public about the permissible acoustic pollution for different districts and times of day. The aim of this work was to analyse data from the NMN of the city of Huelva (Spain), in order to study the influence on the noise of re-asphalting the busiest streets. The street pavements improve LAeq, 24 h from 3 up to 8 dB(A), depending on the type of the route. These results could be used by council authorities in deciding when to undertake the re-asphalting of the streets of Huelva, and to select the type of asphalt that should be used.
Źródło:
Archives of Acoustics; 2018, 43, 1; 103-112
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An Inverse Method to Obtain Porosity, Fibre Diameter and Density of Fibrous Sound Absorbing Materials
Autorzy:
Alba, J.
del Rey, R.
Ramis, J.
Arenas, J. P.
Powiązania:
https://bibliotekanauki.pl/articles/177007.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
sound absorption
fibrous materials
porous material
material characterization
Opis:
Characterization of sound absorbing materials is essential to predict its acoustic behaviour. The most commonly used models to do so consider the flow resistivity, porosity, and average fibre diameter as parameters to determine the acoustic impedance and sound absorbing coefficient. Besides direct experimental techniques, numerical approaches appear to be an alternative to estimate the material's parameters. In this work an inverse numerical method to obtain some parameters of a fibrous material is presented. Using measurements of the normal incidence sound absorption coefficient and then using the model proposed by Voronina, subsequent application of basic minimization techniques allows one to obtain the porosity, average fibre diameter and density of a sound absorbing material. The numerical results agree fairly well with the experimental data.
Źródło:
Archives of Acoustics; 2011, 36, 3; 561-574
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Acoustic Influence of Vehicles on a Protected Natural Area in the Southwest of the Iberian Peninsula
Autorzy:
Sánchez-Sánchez, R.
Fortes-Garrido, J. C.
Bolívar, J. P.
Powiązania:
https://bibliotekanauki.pl/articles/176775.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
natural sounds
soundscapes
noise
protected natural area
Opis:
Natural sounds are essential elements for ecosystems, and therefore necessary for many ecological functions, forming what is called “natural soundscapes”. The Natural Reserve Laguna del Portil (NRLP), located in the southwest of the Iberian Peninsula, is an ecosystem which was declared by Spanish authorities as Protected Natural Reserve. In the south area of the NRLP, there is a regional road with high traffic intensity, which affects the soundscapes of this natural reserve. In this study, the road potential noise impact on the natural sounds of the NLRP is analysed. This analysis was done both in winter and summer, and also using two independent methods: 1) spatial sampling measures in 43 different points of the NRL; and 2) noise mapping using noise levels prediction software. From the comparison of the results of both methods and seasons the following conclusions were reached: 1) an approach to the natural soundscape of NRLP both in winter and summer, 2) the acoustic impact of the road on the NRLP, and 3) the variation of the traffic noise depending on the distance to the road, and its seasonal variation. This study could be to improve the management of the NRLP and to help to preserve the natural soundscape of the reserve.
Źródło:
Archives of Acoustics; 2018, 43, 2; 177-185
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Numerical Approach to Calculate the Radiation Efficiency of Baffled Planar Structures Using the Far Field
Autorzy:
González-Montenegro, M. A.
Jordan, R.
Lenzi, A.
Arenas, J. P.
Powiązania:
https://bibliotekanauki.pl/articles/176303.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
propagating matrix
far field
sound power
structural finite element analysis
Opis:
A numerical method is developed for estimating the acoustic power of any baffled planar structure, which is vibrating with arbitrary surface velocity profile. It is well known that this parameter may be calculated with good accuracy using near field data, in terms of an impedance matrix, which is generated by the discretization of the vibrating surface into a number of elementary radiators. Thus, the sound pressure field on the structure surface can be determined by a combination of the matrix and the volume velocity vector. Then, the sound power can be estimated through integration of the acoustic intensity over a closed surface. On the other hand, few works exist in which the calculation is done in the far field from near field data by the use of radiation matrices, possibly because the numerical integration becomes complicated and expensive due to large variations of directivity of the source. In this work a different approach is used, based in the so-called Propagating Matrix, which is useful for calculating the sound pressure of an arbitrary number of points into free space, and it can be employed to estimate the sound power by integrating over a finite number of pressure points over a hemispherical surface surrounding the vibrating structure. Through numerical analysis, the advantages/disadvantages of the current method are investigated, when compared with numerical methods based on near field data. A flexible rectangular baffled panel is considered, where the normal velocity profile is previously calculated using a commercial finite element software. However, the method can easily be extended to any arbitrary shape. Good results are obtained in the low frequency range showing high computational performance of the method. Moreover, strategies are proposed to improve the performance of the method in terms of both computational cost and speed.
Źródło:
Archives of Acoustics; 2014, 39, 2; 249-260
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-15 z 775

Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies