Temat: variations - Katalog OPAC zbiorów

Skocz do pozycji: 1.

Tytuł:: Phenotypic characterization of indigenous chicken population in Gwer-West, Benue State, Nigeria
Autorzy:: Rotimi, E. A.
Egahi, J. O.
Adeoye, A. A.
Powiązania:: https://bibliotekanauki.pl/articles/1182895.pdf
Data publikacji:: 2016
Wydawca:: Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:: characterization
chicken
native
variations
morphometery
Opis:: This study was carried out to characterize native chickens of Gwer-West Local Government Area of Benue State, Nigeria, based on some phenotypic traits. A total of seven thousand and ninety-one (7091), 4624 females and 243 males, mature native chickens were randomly sampled from the study area. The study covered eleven (11) council wards (North Bank I, Wadata, Modern Market, Wala-mayo, Central South Mission, Bar, Fiidi, Agan, Clerk Mission, Mbalagh and North Bank II). The study was conducted between June and August 2012. Parameters examined include live body weight, body length, feather types, head shape, plumage colour, shank colour, beak colour, comb type ear-lobe colour and wattle colour. Majority of the chickens sampled are female (65.21%). The most predominant feather type, head shape, plumage colour, shank colour, beak colour, comb type, ear-lobe colour and wattle colour were normal (88.49%), plain (92.42%), complete brown (29.01%), white (41.19%), single (88.49%), white (79.37%) and white (68.02%) respectively. Mean live body weight of males (1.38 kg ±0.20) was significantly (p<0.05) heavier than the mean live body weight of females (1.23 kg ±0.19). Males were also superior to females in terms of body length (53.77 cm ±6.01 and 49.05 cm ±5.40 respectively). The study revealed that most of the parameters measured revealed distinctive variations, providing the basis for further characterization of native birds breeds, therefore future study can be concentrated on selection for qualitative traits of interest.
Źródło:: World Scientific News; 2016, 53, 3; 343-353
2392-2192
Pojawia się w:: World Scientific News
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Skocz do pozycji: 2.

Tytuł:: Seasonal variation in heavy metal distribution in the sediments of selected dams in Nasarawa State, Nigeria
Autorzy:: Gav, B. L.
Aremu, M. O.
Etonihu, A. C.
Powiązania:: https://bibliotekanauki.pl/articles/1109614.pdf
Data publikacji:: 2018
Wydawca:: Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:: Dams
Heavy metal
Seasonal variations
sediments
Opis:: The study was carried out to ascertain seasonal variation in heavy metal distribution in sediments from Dams located in Nasarawa State, Nigeria. Sediment samples were collected twice each at two different seasons for two years from May to September, 2014 and November-December, 2014 to March, 2015 for wet and dry seasons, respectively. Similarly, sediment samples were collected from May to September, 2015 and November-December, 2015 to March, 2016 for wet and dry seasons, respectively. The samples were then assessed for heavy metal properties, using atomic absorption spectrophotography (AAS). Analysis of variance (ANOVA) was then applied. The mean results of the heavy metal levels showed high values in dry seasons and low values in wet seasons in the two years of the study. Herein, the results of ANOVA revealed significant difference in the heavy metal concentrations between the seasons, dams and years. Our study also indicated that for heavy metals, the levels determined in sediments were within the WHO acceptable standards, except for Pb and Mn. These exceeded the WHO acceptable standards for drinking water. Based on these results, the dam waters are, therefore, polluted and unsuitable for human consumption, except after treatment.
Źródło:: World News of Natural Sciences; 2018, 20; 148-159
2543-5426
Pojawia się w:: World News of Natural Sciences
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Skocz do pozycji: 3.

Tytuł:: Seasonal changes of carbohydrate content in Antarctic krill (Euphausia superba Dana)
Autorzy:: Kołakowski, Edward
Szyper-Machowska, Lidia
Powiązania:: https://bibliotekanauki.pl/articles/2053142.pdf
Data publikacji:: 1989
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:: Antarctic krill
carbohydrate fractions
seasonal variations
Źródło:: Polish Polar Research; 1989, 10, 2; 133-139
0138-0338
2081-8262
Pojawia się w:: Polish Polar Research
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Skocz do pozycji: 4.

Tytuł:: An improved model of a three phase induction motor incorporating the parameter variations
Autorzy:: Dey, A.
Tripathi, A.
Singh, B.
Dwivedi, B.
Chandra, D.
Powiązania:: https://bibliotekanauki.pl/articles/262793.pdf
Data publikacji:: 2008
Wydawca:: Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie
Tematy:: mathematical modeling
transient model
parameter variations
Opis:: A great deal of work is being done on the betterment of control through simulation of the electric drives used for various high-power purposes. The authenticity of the simulated results is based on the accurate modeling of the various parts of the electric drive system. Three–phase Induction motors form an extremely important part of the modern day electric drive system and their usage is continuously on a rise owing to their inherent properties of ruggedness, minimum maintenance requirements and continually increasing efficiencies. Usually the three-phase Induction motor model used in various research works does not incorporate stator and rotor core losses, stator and rotor stray load losses and magnetizing saturation and rotor conductor skin effects. The present paper aims at developing a threephase Induction motor model taking the above losses and effects into account. The dynamic linking of the model to a thermal model considering the temperature dependent resistive elements is an added feature. The motor model described in this paper is the extension of the conventional 2-phase lumped-parameter induction motor model. The biggest advantage is that the model is user-programmable in MA TLAB environment and can be used for system level transient studies. The simulation results of the developed model, with various parameter variations taken into account and subjected to sudden changes in load, show better torque and speed performances of the motor both in steady state and dynamic conditions.
Źródło:: Electrical Power Quality and Utilisation. Journal; 2008, 14, 1; 73-78
1896-4672
Pojawia się w:: Electrical Power Quality and Utilisation. Journal
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Skocz do pozycji: 5.

Tytuł:: Somaclonal variation during Picea abies and P. omorika somatic embryogenesis and cryopreservation
Autorzy:: Hazubska-Przybył, Teresa
Dering, Monika
Powiązania:: https://bibliotekanauki.pl/articles/952041.pdf
Data publikacji:: 2017
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:: microsatellites
somaclonal variations
somatic embryogenesis
spruce
Opis:: Embryogenic cultures of plants are exposed to various stress factors both in vitro and during cryostorage. In order to safely include the plant material obtained by somatic embryogenesis in combination with cryopreservation for breeding programs, it is necessary to monitor its genetic stability. The aim of the present study was the assessment of somaclonal variation in plant material obtained from embryogenic cultures of Picea abies (L.) Karst. and P. omorika (Pančić) Purk. maintained in vitro or stored in liquid nitrogen by the pregrowth-dehydration method. The analysis of genetic conformity with using microsatellite markers was performed on cotyledonary somatic embryos (CSE), germinating somatic embryos (GSE) and somatic seedlings (SS), obtained from tissues maintained in vitro or from recovered embryogenic tissues (ETc) and CSE obtained after cryopreservation. The analysis revealed changes in the DNA of somatic embryogenesis-derived plant material of both Picea spp. They were found in plant material from 8 out of 10 tested embryogenic lines of P. abies and in 10 out of 19 embryogenic lines of P. omorika after in vitro culture. Changes were also detected in plant material obtained after cryopreservation. Somaclonal variation was observed in ETc and CSE of P. omorika and at ETv stage of P. abies. However, most of the changes were induced at the stage of somatic embryogenesis initiation. These results confirm the need for monitoring the genetic stability of plants obtained by somatic embryogenesis and after cryopreservation for both spruce species.
Źródło:: Acta Biologica Cracoviensia. Series Botanica; 2017, 59, 1
0001-5296
Pojawia się w:: Acta Biologica Cracoviensia. Series Botanica
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Skocz do pozycji: 6.

Tytuł:: The relationship between CA repeat polymorphism of the IGF-1 gene and the structure of motor skills in young athletes
Autorzy:: Karpowicz, Krzysztof
Krych, Katarzyna
Karpowicz, Małgorzata
Nowak, Witold
Gronek, Piotr
Powiązania:: https://bibliotekanauki.pl/articles/1038522.pdf
Data publikacji:: 2018
Wydawca:: Polskie Towarzystwo Biochemiczne
Tematy:: genetic variations
motor skills
young athletes
Opis:: The map of candidate genes that can potentially affect physical fitness becomes larger every year, and they are associated with such aspects as respiratory and cardiovascular stability; body build and composition - especially muscle mass and strength; carbohydrate and lipid metabolism; response to training; and exercise intolerance.The aim of this study was to analyze the relationship between the CA repeat polymorphism of the P1 promoter of the IGF1 gene and the structure of motor skills in the two groups of Polish young athletes in 2007-2009. In this study, 350 young sportsmen representing different sports disciplines were examined (age = 15.5 ± 0.5 years), by genotyping the IGF1 gene and determining the structure of motor skills using the International Physical Fitness Test (IPFT) battery. The multiple stepwise regression was used to determine the impact of the investigated motor skills on the indicator of the overall physical fitness, measured by the total score of the International Physical Fitness Test (IPFT). The analysis showed some regularity related to the character of the IGF1 gene polymorphism. It can be concluded that the two groups of young boys athletes practicing various sports disciplines (kinds of physical exercise) displayed similar associations between CA repeat polymorphism of the P1 promoter of the IGF1 gene and the level of motor effects. Our results suggest that this polymorphism may be a genetic marker of the physical performance phenotype. We demonstrated that CA repeat polymorphism of the P1 promoter of the IGF1 gene was associated with strength predispositions in the homozygous and non-carriers groups. In the group who were heterozygous it was speed-strength aptitudes.
Źródło:: Acta Biochimica Polonica; 2018, 65, 1; 43-50
0001-527X
Pojawia się w:: Acta Biochimica Polonica
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Skocz do pozycji: 7.

Tytuł:: Two-dimensional stable Lavrentiev phenomenon with and without boundary conditions
Autorzy:: Caetano, A.
Sarychev, A.
Seabra, D.
Powiązania:: https://bibliotekanauki.pl/articles/970549.pdf
Data publikacji:: 2005
Wydawca:: Polska Akademia Nauk. Instytut Badań Systemowych PAN
Tematy:: multidimensional calculus of variations
Lavrentiev phenomenon
Opis:: This work contains examples of regular 2D problems of the Calculus of Variations which exhibit stable Lavrentiev phenomenon, under different types of boundary conditions.
Źródło:: Control and Cybernetics; 2005, 34, 3; 689-707
0324-8569
Pojawia się w:: Control and Cybernetics
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Skocz do pozycji: 8.

Tytuł:: Tworzenie szeregów czasowych natężenia dopływu i parametrów jakości ścieków na potrzeby symulacji pracy oczyszczalni komunalnych
Simulating the performance of municipal wastewater treatment plants: Generation of the time series of inflow rate and quality parameters of the wastewater
Autorzy:: Sobota, J.
Szetela, R.
Powiązania:: https://bibliotekanauki.pl/articles/236468.pdf
Data publikacji:: 2006
Wydawca:: Polskie Zrzeszenie Inżynierów i Techników Sanitarnych
Tematy:: oczyszczalnia ścieków
natężenie dopływu
jakość ścieków
szereg czasowy
zmienność sezonowa
symulacja
water treatment plant
flow rate
wastewater characteristics
time series
diurnal variations
daily variations
seasonal variations
simulation
Opis:: Możliwość tworzenia szeregów czasowych wejść oczyszczalni komunalnych, opisujących z godzinowym krokiem wartości natężenia przepływu i stężeń zanieczyszczeń dopływających ścieków, jest istotna w zagadnieniach projektowania i eksploatacji procesów oczyszczania ścieków. W pracy przedstawiono propozycje metody tworzenia takich wejść. Jej istotą jest wyodrębnienie z surowych przebiegów czasowych odpowiednich składowych deterministycznych (uśrednionych dobowych i rocznych "szkieletów" natężenia dopływu i stężenia zanieczyszczeń) i losowych, których modele są budowane osobno, a ich połączenie daje model generatora wejść. Wykazano, że generator dobrze naśladuje charakterystyczną zmienność sezonową, dobową i godzinową wejść oczyszczalni. Pozwala to na jego zastosowanie w analizach symulacyjnych, służących optymalizacji procesów technologicznych i strategii ich sterowania. Obecnie w większości oczyszczalni brak jest odpowiednio bogatych, kilkuletnich zbiorów danych źródłowych, obejmujących charakterystykę jakości ścieków surowych, niezbędnych do opracowania odpowiedniego generatora wejść. Na potrzeby takich przypadków zaproponowano metodologię alternatywną, wykorzystującą stwierdzone zależności korelacyjne pomiędzy średnim dobowym natężeniem dopływu ścieków i średnimi dobowymi wartościami wskaźników zanieczyszczeń ścieków surowych.
The potentiality for generating the time series of the inputs for municipal wastewater treatment plants such that describe, in hourly steps, the flow rates and concentrations of pollutants in the influent wastewater stream is of importance to the design and control of wastewater treatment processes. In this paper, a method is proposed for the generation of such inputs. The method consists in separating from the raw time series appropriate deterministic (averaged daily and annual 'skeletons' of inflow rate and pollutant concentrations) and stochastic components; their models are constructed separately, and the combination of those models produces the model of the input generator. The generator well imitates the characteristic seasonal, daily and hourly variability of the inputs for the wastewater treatment plant and can therefore be applied to simulation analyses aimed at optimizing technological processes and relevant control strategies. Presently, only few wastewater treatment plants in Poland are in possession of comprehensive data sets including the characteristic of raw wastewater quality recorded for several years, which are needed when designing an input generator. With these thoughts in mind, an alternative methodology is proposed, where use is made of the correlations between the average daily rate of wastewater inflow and the average daily concentrations of the pollutants in raw wastewater.
Źródło:: Ochrona Środowiska; 2006, R. 28, nr 2, 2; 39-46
1230-6169
Pojawia się w:: Ochrona Środowiska
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Skocz do pozycji: 9.

Tytuł:: Monitoring of ocean current perturbations using acoustic phase variations
Autorzy:: Zieliński, A.
Butowski, M.
Kraeutner, P.
Powiązania:: https://bibliotekanauki.pl/articles/332840.pdf
Data publikacji:: 2009
Wydawca:: Polskie Towarzystwo Akustyczne
Tematy:: ocean current perturbations
acoustics phase variations
hydroacoustics
Opis:: In this paper, we review an acoustic method for measuring both average ocean current speed and sound speed along an acoustic path. The method requires two or more stations on the sea floor, synchronized through a connecting underwater electric cable, that can transmit and receive an acoustic signal and The method is based on reciprocal acoustic transmissions to determine time of flight in both the forward and reverse directions. A specific implementation of this method is proposed. We also consider a novel method for monitoring ocean current perturbations through acoustic phase measurements. In simplest form, a continuous sinusoidal signal is transmitted from one station to a second station. Any variations in ocean current speed will introduce a phase shift in the received signal proportional to the time derivative of the current speed. This effect has been demonstrated through ultrasonic in-air experiments. Finally, the two methods are combined into a single system that continuously measures small-scale ocean current velocity changes.
Źródło:: Hydroacoustics; 2009, 12; 237-248
1642-1817
Pojawia się w:: Hydroacoustics
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Skocz do pozycji: 10.

Tytuł:: Variation of the cholesterol content in breast milk during 10 days collection at early stages of lactation
Autorzy:: Kamelska, Anna
Pietrzak-Fiećko, Renata
Bryl, Krzysztof
Powiązania:: https://bibliotekanauki.pl/articles/1039741.pdf
Data publikacji:: 2012
Wydawca:: Polskie Towarzystwo Biochemiczne
Tematy:: FTIR-ATR spectroscopy
human milk
cholesterol variations
Opis:: More and more research is done concerning nutritional programming. Human milk nutrients which are consumed by infants can influence their health in later life. High level of cholesterol in human milk paradoxically lowers the cholesterol concentration in blood in adults. During the course of human lactation the cholesterol concentration decreases from 31 mg/100cm3 (colostrum) to 16 mg/100 cm3 (mature milk). According to Scopesi et al., 2002, Clin Nutr 21: 379-384, cholesterol concentration in mature milk ranged from 6.5 to 18.4 mg/100 cm3. The aim of the study was to assess the variations in breast milk cholesterol content during 10 day collection at early lactation. 48 samples of human milk were analyzed. Mean age of women was 31 years. Women were collecting samples during 10 days of an early lactation stage (1-3 months after delivery). An Attenuated Total Reflectance Fourier Transformed Infrared (FTIR-ATR) method for easy and rapid determination of cholesterol in human milk was elaborated. Cholesterol content assessed by the FTIR method ranged from 3.36 to 12.98 mg/100 cm3. Results indicate that milk cholesterol concentration during 10 consecutive days of early lactation is highly variable. Cholesterol content depends on an individual. Therefore it is suggested that not only the period of lactation but also mother's diet, age, season and place of residence are important factors determining cholesterol content.
Źródło:: Acta Biochimica Polonica; 2012, 59, 2; 243-248
0001-527X
Pojawia się w:: Acta Biochimica Polonica
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Informacja

Wyszukujesz frazę "variations" wg kryterium: Temat

Źródło danych

Dostawca treści

Kolekcja

Rok wydania

Wydawca

Temat

Autor

Typ dokumentu

Język