1,517 research outputs found

    Influence of low temperatures on heat balance in easily assembled premises of different types

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    The purpose of this work was to analyze the thermal balance of easily assembled premises of different types and sizes during the periods of low average daily temperatures. The research was conducted during the winter period of 2020–2021 in the Kyiv region. The used material was easily assembled premises of different types and sizes: easily assembled ones without insulation elements; with elements of warming and premises with deep-litter. In each of the studied premises were kept 400 dairy cows. The studies were performed during two periods: the first period had ambient temperatures from -10 to -14.9 °C and the second one from -15.0 °C and below. In our studies, the average daily temperature (during the ambient temperature from -10 to 14.9 °C) in easily assembled premises with the use of insulation elements was 6.20 and 5.31 °C higher than in premises without insulation and deep-litter. A similar trend was observed during the period of lowering the ambient temperature up to 15 °C and below. Thus, the advantage of the premises without insulation constituted 6.28 °C, and of the premises with deep-litter per 5.84 °C, respectively. It was found that keeping in easy-to-assemble premises with insulation elements, the consumption of free thermal energy from the whole herd during the experimental periods was lower compared to the keeping in a boxing cowshed and a cowshed with deep litter. This is due to the smaller range of fluctuations in the average daily temperature in a room with insulation elements. A similar trend was observed for energy consumption through enclosing structures and for moisture evaporation and, accordingly, total heat consumption. In general, heat deficiency was observed during the keeping of cows in the investigated premises of easily assembled type at negative temperatures (-10–14.9 and -15 °С and above). Accordingly, the thermal balance of the premises was negative. The highest values of heat balance among easily assembled premises in both research periods were observed for keeping in rooms that used insulation elements

    Bioenergetic and ethological features of the first-calf heifers of different genotypes

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    The aim of this work was to study bioenergetic and ethological indicators in crossbred first-calf heifers compared to purebred first-calf heifers. The research was conducted on the first-calf heifers of Ukrainian Black-Pied dairy breed and first-generation crossbreeds obtained as a result of crossing with Brown Swiss breed, as well as, on the first-calf heifers of Ukrainian Red-Pied dairy breed and first-generation crossbreeds obtained as a result of crossing Ukrainian Red-Pied dairy with Montbéliarde breed. The purebred Black-and Red-Pied first-calf heifers prevailed over crossbreed first-calf heifers on the indicator of milk yield for 305 days of lactation by 106.45 and 218.36 kg, respectively. Accordingly, the indicators of average daily milk yield were also higher by 0.35 and 0.72 kg and the indicators of average daily milk yield adjusted by 4 % fat content per 0.15 and 0.16 kg. At the same time, the indicator of average fat content in milk prevailed in crossbreeds of Black-Pied and Brown Swiss breed by 0.08 % compared to purebred Black-Pied breeds, and in Red-Pied crossbreeds with Montbéliarde breed by 0.16 % compared to purebred Red-Pied breeds. The purebred Black-Pied first-calf heifers had an advantage by 2.04 MJ compared to crossbreeds, while the Red-Pied first-calf heifers had a slight advantage by 0.06 MJ compared to crossbreed first-calf heifers on the indicator of daily cost of exchange energy (EE). The purebred Black-and Red-Pied first-calf heifers had higher cost of exchange energy allocated with milk compared to crossbreed first-calf heifers by 0.42 and 0.82 MJ. They also had higher cost of exchange energy rates for heat products by 0.79 and 0.25 MJ. According to the energy index indicator, purebred Black - and Red-Pied first-calf heifers prevailed over crossbreeds first-calf heifers by 0.16 and 0.07 %, respectively. The same trend was observed in relation to the productive index indicator. The purebred Black-and Red-Pied first-calf heifers had a slight advantage by 0.001 and 0.002 kg adjusted by 4 % of milk fat content per 1 MJ. According to the indicators of daily behavioral reactions, no special differences between a purebred and crossbreed were found

    Composition and cheese suitability of milk from local Ukrainian cows and their crossbreedings with Montbeliarde breed

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    Received: July 19th, 2022 ; Accepted: September 8th, 2022 ; Published: September 12th, 2022 ; Correspondence: [email protected] aim of this work was to compare the qualitative composition of milk and its suitability for cheese processing at cows of local Ukrainian Red-Spotted breed (URS) and their crossbreeds with Montbeliarde (MO) breed. The research was conducted at commercial farm in the Vinnytsia region, Ukraine (48° 57′01″ n.l., 28° 47′09″ e.l). At farm, two groups of purebred and crossbred first lactation cows-analogues with a population of 20 heads in each were formed. The use of crossbreeding cows URS × Montbéliarde breed had a positive effect on the milk composition and cheese suitability. It was established that local purebred cows exceeded purebred counterparts in daily milk yield by 2.47 kg. When the content of fat, protein and lactose in milk was higher in crossbreed group by 0.19, 0.19 and 0.12%, respectively. In addition, crossbreed cows surpassed purebred counterparts for the energy value of 1 kg of milk and theoretically possible output of rennet cheese by 0.142 MJ and 0.61 kg. The duration of the coagulation phase of milk obtained from crossbred cows was shorter than that of purebred analogues by 1.54 minutes

    Detailed description of accelerating, simple solutions of relativistic perfect fluid hydrodynamics

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    In this paper we describe in full details a new family of recently found exact solutions of relativistic, perfect fluid dynamics. With an ansatz, which generalizes the well-known Hwa-Bjorken solution, we obtain a wide class of new exact, explicit and simple solutions, which have a remarkable advantage as compared to presently known exact and explicit solutions: they do not lack acceleration. They can be utilized for the description of the evolution of the matter created in high energy heavy ion collisions. Because these solutions are accelerating, they provide a more realistic picture than the well-known Hwa-Bjorken solution, and give more insight into the dynamics of the matter. We exploit this by giving an advanced simple estimation of the initial energy density of the produced matter in high energy collisions, which takes acceleration effects (i.e. the work done by the pressure and the modified change of the volume elements) into account. We also give an advanced estimation of the life-time of the reaction. Our new solutions can also be used to test numerical hydrodynamical codes reliably. In the end, we also give an exact, 1+1 dimensional, relativistic hydrodynamical solution, where the initial pressure and velocity profile is arbitrary, and we show that this general solution is stable for perturbations.Comment: 34 pages, 8 figures, detailed write-up of http://arxiv.org/abs/nucl-th/0605070

    Amino acid composition of milk from Finnish Ayrshire cows and their crossbreeds with the Norwegian Red breed

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    Received: July 28th, 2023 ; Accepted: October 18th, 2023 ; Published: October 30th, 2023 ; Correspondence: [email protected] purpose of this work was to study the effect of crossing of Finnish Ayrshire cows with Norwegian Red breed under the conditions of the temperate climate of Ukraine on indicators of the qualitative composition of milk, the content of essential amino acids (EAA) and their biological value. The research was conducted at a commercial farm in the Poltava region (50°02′39″ n.l., 33°51′09″ e.l.) using Finnish Ayrshire cows and their crosses with the Norwegian Red breed. According to the indicators of fat, protein and lactose content in the group of crossbred firstborns, purebred counterparts prevailed by: 0.22; 0.09 and 0.07%, respectively, and the energy value of 1 kg of milk by 0.053 Mcal kg-1 . For milk protein of Finnish Ayrshires, the first limiting EAA (lower than the recommended content in the reference protein) was methionine + cystine (affects the rate of clot formation during cheese making), the content of which was 96.3%. In the protein of crossbred cows EAA in which amino acid score (AAS) was less than 100%, were not detected. Phenylalanine + tyrosine - 143.7% and leucine - 122.1%, which are aromatic amino acids and affect the taste properties of milk, were the most excessive. The protein of crossbreds was characterized by a slightly higher value of the total utilitarian coefficient, compared to purebred counterparts (by 12.77%). Also, the aminogram of the crossbred group was closer to ‘ideal’

    Nematic twist-bend phase with nanoscale modulation of molecular orientation

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    A state of matter in which molecules show a long-range orientational order and no positional order is called a nematic liquid crystal. The best known and most widely used (for example, in modern displays) is the uniaxial nematic, with the rod-like molecules aligned along a single axis, called the director. When the molecules are chiral, the director twists in space, drawing a right-angle helicoid and remaining perpendicular to the helix axis; the structure is called a chiral nematic. Here using transmission electron and optical microscopy, we experimentally demonstrate a new nematic order, formed by achiral molecules, in which the director follows an oblique helicoid, maintaining a constant oblique angle with the helix axis and experiencing twist and bend. The oblique helicoids have a nanoscale pitch. The new twist-bend nematic represents a structural link between the uniaxial nematic (no tilt) and a chiral nematic (helicoids with right-angle tilt)

    Вплив способу видалення і зберігання гною на якість органічної продукції

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    The aim of this article was to compare the quality of manure in different ways of its removal and storage for environmental pollution. The research was conducted in three farms of Kyiv region with different methods of manure removal, storage and processing: using deep long-lasting straw litter (manure removal three times a year); with manure processing in a closed bioreactor-fermenter of the closed type; with manure settling in open lagoons. In all farms, the average annual livestock is 400 dairy cows. Samples for analysis of manure (processing waste) were taken the day before export to the field. The average daily air temperature during sampling was +21.3 °C. In terms of the sum of nitrogen, phosphorus and potassium content in 1 kg of fertilizers, the highest indicators were observed for the variant of keeping in deep litter – 7.69 g. intermediate bioreactors-fermenters observed intermediate values – 6.69 g. The highest moisture content of manure was during storage in the lagoon – by 19.71 % and 1.38 % more compared to the option on deep litter and in the bioreactor-fermenter. The lowest number of weed seeds was for storage in deep litter – 84 pcs/ml, which is 19 and 23 pcs/ml more than for processing in a bioreactor-fermenter and storage in the lagoon. The indicator of weed germination, which is very important from the point of view of future use of manure as an organic fertilizer in general, had positive indicators for all storage (processing) options. The germination rate of weeds for storage in deep litter was 5.72 %, which is 3.14 and 4.42 % less than for processing in a bioreactor-fermenter and in the lagoon. The largest emissions of N2O (nitric oxide) were in the variant of manure storage in the lagoon – 40712.45 kg, which is 39781.88 kg more than in the options of storage in deep litter and in the bioreactor-fermenter. The content of nitrogen, phosphorus, potassium and organic matter of fertilizer obtained from 1 kg of manure from deep litter, exceeded similar indicators of other methods of storage due to daily application of straw.Метою цієї роботи було порівняння впливу складу гною за різних способів його видалення та зберігання на забруднення довкілля. Дослідження проводили у трьох господарствах Київської області з різними способами видалення, зберігання та переробки гною: з використанням глибокої довгонезмінюваної соломʼяної підстилки (видалення гною тричі на рік); з переробкою гною в біореакторі-ферментері закритого типу; з відстоюванням гною у лагунах відкритого типу. У всіх господарствах середньорічне поголівʼя становить 400 дійних корів. Проби для аналізу гною (відходів переробки) відбирали за добу до вивезення в поле. Середня добова температура повітря при відборі проб становила +21,3 °С. За сумою вмісту Азоту, Фосфору та Калію у 1 кг добрив найвищі показники спостерігали за варіанту утримання на глибокій підстилці – 7,69 г. Найменше цих елементів було у добриві, отриманому в результаті зберігання у лагуні – 6,16 г. За варіанту переробки гною у біореакторі-ферментері спостерігали проміжні показники – 6,69 г. Найвищий показник вологості гною був за зберігання в лагуні – 95,25 %, що на 19,71 % та 1,38 % більше порівняно з варіантом накопичення і зберігання у приміщенні (глибока підстилка) та в біореакторі-ферментері. Найменша кількість насіння бурʼянів була за зберігання на глибокій підстилці – 84 шт/мл, що на 19 та 23 шт/мл менше, ніж за переробки у біореакторі-ферментері та зберігання у лагуні. Показник схожості бурʼянів, котрий є дуже важливим з точки зору майбутнього використання гною як органічного добрива, загалом за всіх варіантів зберігання (переробки) мав неоднозначні показники. Показник схожості бурʼянів за зберігання на глибокій підстилці становив 5,72 %, що на 3,14 та 4,42 % менше, ніж за переробки у біореакторі-ферментері та в лагуні. Найбільші викиди N2O (оксид азоту), були за варіанту зберігання гною в лагуні – 40712,45 кг, що на 39781,88 кг більше, ніж за варіантів зберігання на глибокій підстилці та у біореакторі-ферментері. Вміст Азоту, Фосфору, Калію та органічної речовини добрива, отриманого з 1 кг гною із глибокої підстилки, переважав аналогічні показники інших способів зберігання за рахунок щоденного внесення соломи
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