Houses on organic farms in north-east Mazovia: Existing material and construction solutions

The study presents building materials or systems which are described in the literature and are regarded as ecological, results of the investigations on the material and construction solutions in dwelling houses of selected organic farms in north-east Mazovia and prospecting for the influence of organic farming on dwelling houses. To prepare the paper, the literature on ecological building construction and ecological farming was used, visits at farms were made (collection of documentation and conversations with owners) and statistical data on the ecological farms in the Ostrołęka and Maków counties were analysed. The investigations showed that there are no connections between the ecological farming and dwelling houses existing on these farms. The material and construction solutions applied there can be considered as non-ecological, which has been shown on the basis of the method by Dąbkowski (2002b). It has been also noticed that farm owners did not benefit from the rich material heritage (i.a. related to folk architecture) of the described region when building residential houses on their farms

FEM Matrices for Problems of Free Vibrations and Buckling of a Truncated Cone Beam

Proper use of materials is one of the most important criteria of a rational design and shaping of engineering constructions. It requires such dimensioning of each element of the construction which will ensure that the element is matched to its load – and this condition is fulfilled only for beams with variable cross section. Hence, it is essential to develop possibilities of calculations of beams with cross section varying along the beam longitudinal axis. This study provides relevant matrices (i.e. stiffness, mass and initial stress matrix) applied in the Finite Element Method for calculations of natural frequencies and buckling critical forces. The matrices have been derived for beams shaped as a truncated cone with a linear generatrix, supported in various ways. The results have been compared to those obtained for the stair-shaped beams approximating the conical ones; a good concordance of results has been stated

Investigations on the effectiveness of wastewater purification in medium sand with assisting clinoptilolite layer

Model investigations of wastewater purification were carried out in a medium sand bed with an assisting natural clinoptilolite layer 0.10 or 0.25 m thick. The effectiveness of wastewater purification related to basic qualitative parameters was in accordance with the Polish standards on sewage disposal into grounds and surface water. Medium sand soil bed with the assisting natural clinoptilolite layer 0.25 m thick showed on average the removal efficiency regarding TSS higher by 3.3%, total nitrogen by 29.3%, total phosphorus by 25.9%, reduction efficiency regarding BOD5 by 1.1% and COD by 15.9% than that with the thinner clinoptilolite layer. The investigations confirmed that natural clinoptilolite with the granulation 1-5 mm can be used to enhance the removal of nitrogen and phosphorus compounds from wastewater with the application of infiltration drainage. However, very good effect of the TSS removal from the wastewater in the investigated soil beds can lead to their fast clogging under the infiltration drainage. Septic tanks should be designed in such a way that they retain as much TSS as possible, e.g., multi-chamber tanks instead of one-chamber ones

Badania modelowe wydajności i sprawności pracy powietrznego podnośnika z mieszaczem typu PM 50 i z mieszaczem obwodowym

The paper presents the analysis of results of investigations concerning an influence of applied constructive solutions on hydraulic operating conditions of a water-pumping air lift pump. The scope of the investigations encompassed the determination of flow rate and efficiency characteristics of an air lift pump having the discharge pipe with the internal diameter d = 0.04 m. The PM 50 mixer with a perforated rubber membrane, available on the market, as well as a mixer of own design, called circumferential mixer, were tested (the name origins from the fact that the mixer has the shape of a ring which encloses the discharge pipe on its whole circumference). The investigations were performed for three air-water mix delivery heads H: 0.40, 0.80, 1.20 m, for the specified pressure pipe submergence length h = 0.80 m. It has been stated that for both types of the applied mixers the water flow rate Qw increased along with the increase of the air flow rate Qa, reaching maximum, then decreased. However, in both of the applied mixers, the water flow rate Qw permanently decreased as the air-water mix delivery head H increased. The air lift pump achieved higher water flow rate Qw if the circumferential mixer was applied instead of that with perforated rubber membrane. It has been proved that for both of the applied types of mixers the air flow rate Qa in the air lift pump cannot be lower during water pumping than 5.0 m3·h-1 and should not exceed 15.0 m3·h-1 in case of the circumferential mixer and 16.0 m3·h-1 for the perforated rubber membrane mixer. The efficiency h of the tested air lift pump for both of the applied types of mixers decreased when the air-water mix delivery head H increased. The higher efficiency h, however, was obtained for the air lift pump with the circumferential mixer than for the perforated rubber membrane mixer.W artykule przedstawiono analizę wyników badań, dotyczących wpływu stosowanych rozwiązań konstrukcyjnych mieszaczy na hydrauliczne warunki pracy powietrznego podnośnika do tłoczenia wody. Zakres badań obejmował wyznaczenie charakterystyk wydajności i sprawności pracy powietrznego podnośnika o średnicy wewnętrznej rurociągu tłocznego d = 0,04 m. Do badań wykorzystano mieszacz dostępny na rynku typu PM 50 z perforowaną gumową membraną i mieszacz własnej konstrukcji, który nazwano mieszaczem obwodowym (nazwa pochodzi stąd, że ma on kształt pierścienia, który obejmuje rurociąg tłoczny na całym jego obwodzie). Badania wykonano dla trzech wysokości podnoszenia mieszaniny wody i powietrza H: 0,40, 0,80, 1,20 m, przy stałej długość zanurzenia rurociągu tłocznego h = 0,80 m. Stwierdzono, że dla obu zastosowanych typów mieszaczy natężenie przepływu wody Qw rosło wraz ze wzrostem natężenia przepływu powietrza Qa osiągając maksimum, a następnie malało. Natomiast w obu zastosowanych typach mieszaczy wraz ze wzrostem wysokości podnoszenia mieszaniny wody i powietrza H, natężenie przepływu wody Qw tylko malało. Większą wydajność natężenia przepływu wody Qw powietrzny podnośnik uzyskał z mieszaczem obwodowym niż z mieszaczem z perforowaną gumową membraną. Wykazano, że dla obu zastosowanych typów mieszaczy natężenie przepływu powietrza Qa w powietrznym podnośniku podczas tłoczenia wody nie może być mniejsze niż 5,0 m3·h-1 i nie powinno przekraczać dla mieszacza obwodowego 15,0 m3·h-1,, a dla mieszacza z perforowaną gumową membraną 16,0 m3·h-1. Sprawność pracy h badanego powietrznego podnośnika dla obu zastosowanych mieszaczy malała wraz ze wzrostem wysokości podnoszenia mieszaniny wody i powietrza H. Natomiast dla powietrznego podnośnika z mieszaczem obwodowym uzyskano większą sprawność pracy h, niż dla powietrznego podnośnika z mieszaczem z perforowaną gumową membraną

Investigations on the effectiveness of wastewater purification in medium sand with assisting opoka rock layer

The objective of the undertaken investigations was to examine in laboratory conditions whether an introduction of an assisting opoka rock layer with the granulation of 1–6 mm into the ground improves the removal efficiency of nitrogen and phosphorus compounds from domestic sewage. The performed investigations concerned the layer supporting the removal efficiency of domestic sewage in a home sewage treatment plant under infiltration drainage. The model investigations of wastewater purification were carried out in a medium sand bed with an assisting, 0.10 and 0.20 m thick opoka rock layer. The effectiveness of wastewater purification related to basic qualitative indicators (total suspended solids – TSS, BOD5, COD, total nitrogen, total phosphorus) was in line with the Polish standards on sewage disposal into grounds and surface water. The medium sand soil bed with the 0.20 m thick assisting opoka rock layer showed higher effectiveness of wastewater purification than that 0.10 m thick. The application of the 0.20 m thick opoka rock layer increased the removal efficiency regarding TSS by 6.2%, total nitrogen by 20.4%, ammonium nitrogen by 8.3% and total phosphorus by 2.9%, and removal efficiency regarding BOD5 by 1.2% and COD by 1.9% with relation to the 0.10 m thick assisting layer (all percentages − in average). The results confirm that the natural opoka rock with the granulation of 1–6 mm can be used to assist in the removal of nitrogen and phosphorus compounds from wastewater with the application of infiltration drainage

Stateczność i drgania mikroniejednorodnego pasma płytowego spoczywającego na podłożu sprężystym

The paper presents a procedure of calculation of natural frequencies and critical buckling forces of a micro-nonhomogeneous plate band resting on nonhomogeneous elastic subsoil and having any given boundary conditions. The band consists of N parts - cells - called elements, having a constant width l = L/N. Each band element consists of three parts - subelements with variable widths. The two of these subelements are matrix, the third - inclusion placed symmetrically relative to the matrix. Each band element is built of two isotropic materials. The matrix and inclusion bands have the stiffness and mass per area unit as well as they rest on the subsoil. The model has been derived with use of the classical displacement method. The stiffness matrix of any band element and then the band stiffness matrix have been built. An appropriate computer program has been written to calculate natural frequencies and critical buckling forces. A number of tests have been performed to check the working of the program and several calculative examples has been presented in the paper.W pracy przedstawiono sposób obliczania częstości drgań własnych i wyznaczania wartości sił krytycznych mikroniejednorodnego pasma płytowego o dowolnych warunkach brzegowych, spoczywającego na niejednorodnym podłożu sprężystym. Pasmo składa się z N części - komórek, zwanych elementami, o stałej szerokości l = L/N. Każdy element pasmowy składa się z trzech części - subelementów o zmiennych szerokościach. Dwie z nich są osnową, trzecia zaś wtrąceniem symetrycznie położonym względem osnowy. Każdy element pasmowy składa się z dwóch izotropowych materiałów. Pasma osnowy i wtrącenia mają pewne sztywności i masy na jednostkę powierzchni oraz spoczywają na podłożu o pewnej sztywności. Do wyznaczenia częstości drgań własnych i wartości krytycznych zastosowano metodę przemieszczeń. Zbudowano macierz sztywności dowolnego elementu pasmowego, a następnie macierz sztywności pasma. Ułożono odpowiedni program na wyznaczenie częstości drgań własnych i sił krytycznych ze względu na wyboczenie. Wykonano szereg testów sprawdzających działanie programu i podano szereg przykładów obliczeniowych

Real Values of Local Resistance Coefficients during Water Flow through Welded Polypropylene T-Junctions

The paper presents results of investigation of the local resistance coefficient ζ in welded polypropylene T-junctions with the internal diameter 13.2 mm. The investigations were performed on an independently constructed test rig. The scope of investigations encompassed the T-junctions, which were (1) properly warmed up and properly pressed, (2) poorly warmed up and poorly pressed, or (3) excessively warmed up and excessively pressed. The local resistance coefficients ζ determined by measurements according to the standard PN-EN 1267:2012(Designation of the Polish Standard) were compared to those determined with use of the nomograms recommended for designing water supply systems and installations. Real values of the coefficients ζ, obtained in measurements were significantly higher than those read from the nomograms. The local resistance coefficients ζ in welded polypropylene T-junctions depend on water flow velocity and the manufacturing precision of a T-junction joint

Dynamika zmian gospodarstw ekologicznych w powiecie ostrołęckim i przasnyskim

Ecological farming is one of the forms of agricultural activity. The article describes the changes that occurred in the years 2009–2016 in relation to the number of ecological farms in Ostrołęka and Przasnysz counties. The analysis was done using the statistical data acquired from Central Statistical Office of Poland (GUS) and included in the Local Data Bank as well as the data obtained from the Agricultural and Food Quality Inspection (IJHARS). The conducted research allowed to show trends in the development of ecological farms in the counties of Ostrołęka and Przasnysz at the background of Mazovian voivodship and the whole Poland.Rolnictwo ekologiczne jest jedną z form działalności rolniczej. W artykule scharakteryzowano zmiany, jakie zaszły w latach 2009–2016 w odniesieniu do liczby gospodarstw ekologicznych w powiecie ostrołęckim i przasnyskim. Analizę wykonano z wykorzystaniem danych statystycznych GUS, zawartych w BDL-u oraz danych otrzymanych z Inspekcji Jakości Handlowej Artykułów Rolno- Spożywczych. Przeprowadzone badania pozwoliły ukazać tendencje w rozwoju gospodarstw ekologicznych w badanych powiatach na tle województwa mazowieckiego i całej Polski