14 research outputs found

    Proizvodnja i kakvoća kokoši nesilica hranjenih obrocima s niskim fosforom na osnovi žitarica s dodatkom fitaze

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    The purpose of the present study was to evaluate the response of laying hens to the low-phosphorus diets based on different kinds of cereal grains and supplemented with microbial phytase. Laying performance, feed intake, egg shell quality as well as bone strength parameters and Ca, P, Mg and Zn contents in the bones were involved as experimental parameters. At the age of 17 weeks, 288 Lohmann Brown pullets were assigned to the six dietary treatments, each treatment consisting of 12 cages with 4 birds per one. Until the beginning of the laying period the pullets were fed a standard diet containing 145 g of crude protein and 11.3 MJ ME, 4 g non-phytate P and 10.6 g of Ca per kg feed. The experimental diets provided from the first day of laying were based on maize (diets I, II, III) or on a combination of maize, barley and wheat (diets IV, V, VI) and contained about 165 g CP and 11.2 MJ ME/kg. In diets I, III or IV and VI the level of non-phytate phosphorus was decreased to 1.41 g/kg while in control diets (III or V) the amount of non-phytate P was 3.0 g/kg. In low-P diets III and VI microbial 6-phytase was included at the level of 450 FTU/kg diet. The phosphorus level in diets did not affect the laying rate during the experimental period of 53 weeks. The higher P-level in feed enhanced egg shell strength only (P<0.01). Supplementation of low-P-diets with phytase did not affect the performance of hens, such as feed intake and egg quality, however it improved the egg shell strength as compared to low-P unsupplemented groups. Regarding strength and elasticity of the tibia, the P-level and phytase supplement were without visible effects. The best parameters that characterize the bone quality were obtained by addition of 3 g of non-phytate P level per kg of diets.Svrha ovog istraživanja bila je ocijeniti odgovor kokoši nesilica na obroke s niskim fosforom na bazi raznih vrsta žitarica s dodatkom mikrobijelne fitaze. Nesenje, unos hrane, kakvoća ljuske jaja kao i parametri čvrstoće kosti i sadržaj Ca, P, Mg i Zn u kostima bili su obuhvaćeni kao pokusni parametri. U dobi od 17 tjedana 288 pilenki Lohmann Brown izabrano je za šest hranidbenih tretmana, a svaki tretman sastojao se od 12 kaveza po 4 pilenke. Do početka nesenja pilenke su hranjene standardnim obrocima koji su sadržavali 145 g sirovih bje¬lančevina i 11.3 MJ ME, 4 g nefitinskog P i 10.6 g Ca po kilogramu hrane. Pokusni obroci su se prvog dana nesenja temeljili na kukuruzu (obro¬ci I, II, III) ili na kombinaciji kukuruza, ječma i pšenice (obroci IV, V, VI) i sadržavali su oko 165 g CP i 11.2 Mj ME/kg. U obrocima I, III ili IV i VI razina nefitinskog fosfora smanjena je na 1.41 g/kg dok je u kontrolnim obrocima (III ili V/) količina nefitinskog P bila 3.0 g/kg. U obrocima s niskim P (III i VI) uključena je mikrobijelna 6-fitaza na razini od 450 FTU/ kg obroka. Razina fosfora u obrocima nije djelovala na postotak nesivosti u pokusu od 54 tjedna. Više razine P u hrani povećale su samo čvrstoću ljuske jajeta. (P < 0,01). Dodavanje fitaze u obroke s niskim P nije dje¬lovalo na unos hrane i kakvoću jaja, međutim poboljšalo je čvrstoću ljuske jajeta u usporedbi sa skupinama s niskim P bez dodataka. Što se tiče čvrstoće i elastičnosti goljenice, razina P i dodavanje fitaze nije imalo vidljivih učinaka. Najbolji parametri koji karakteriziraju kakvoću kosti dobiveni su dodavanjem 3 g nefitinskog P na kg obroka

    The influence of grinding speed on the creep-feed grinding process

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    Grinding is usually the last stage of the technological process and determines the quality of manufactured products. One of the varieties of grinding more and more often used in practice is deep grinding which is called Creep-Feed Grinding. It is characterized by a high value of grinding infeed and slow feed. Technological parameters such as the depth of grinding and the speed of feed have a significant impact on the quality of the workpiece. However, also the grinding speed has an influence on the grinding process and the result of machining. Therefore, experimental studies on the impact of grinding speed on the surface roughness and grinding force components were carried out. The tests were realized in the deep-grinding grinding process of Inconel 718 with a grinding wheel made of mixture of sintered alumina and ruby corundum

    Trickling Filter for High Efficiency Treatment of Dairy Sewage

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    The article presents the results of the research on the possibility of using a trickling filter for high efficiency treatment of dairy sewage. Nowadays, to the best of the authors’ knowledge, it is possible to change the activated sludge system to the trickling filter technology, especially in small dairy plants with lower raw sewage parameters in comparison to larger plants. In the research, dairy wastewater after dissolved air flotation (DAF) process was treated with a laboratory scale Gunt CE701e research model which allows to control the basic parameters of the treatment with a trickling filter (TF). The conducted study included determining the changing sewage parameters during the DAF process, as well as the trickling filter (TF) efficiency. Such parameters as Biological Oxygen Demand (BOD), Chemical Oxygen Demand (COD), total Organic Carbon (TOC), total Kjeldahl nitrogen (TKN) and total phosphorous (TP) were checked. The research results confirmed the possibility of high efficiency treatment of dairy sewage with DAF and trickling filter technologies. The average efficiency of DAF treatment was 59.3% for BOD, 49.0% for COD and 80.0% for TP, while the average treatment efficiency of TF was 87.3%, 78.3% and 27.9% without recirculation and 95.2%, 85.5% and 42.0% with 100% recirculation applied, respectively. The load of TF during the operation without recirculation was on average 0.22 kgBOD5∙m-3∙d-1 and 0.25 with 100% recirculation. Applying recirculation allowed to reach the BOD, COD and total phosphorus standards for the sewage discharged to a receiver from Bielmlek dairy WWTP. On the other hand, the concentration of total nitrogen exceeded the permitted standards in this facility

    Adaptive control of the HPC milling process

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    W artykule przedstawiono podział oraz ogólną charakterystykę najczęściej stosowanych w obrabiarkach CNC systemów sterowania adaptacyjnego. Na podstawie przeprowadzonych badań doświadczalnych procesu wysokowydajnego frezowania stopów aluminium określono stopień skrócenia czasu obróbki spowodowany zastosowaniem wybranego układu sterowania adaptacyjnego.This paper presents an overview of the division of the most widely used adaptive control systems. Figure 1 shows an example of adaptive control off-line, and in Section 2 of the paper there is described the on-line adaptive control system as an example of Marpos ARTIS. In Section 3 the high-performance milling (HPC) of aluminum alloys is discussed. In the machining center HSC 55 Linear with implemented module ARTIS there were performed experimental investigations of the machining process with and without adaptive control. The experimental setup is shown in Figure 4. The experiment was carried out for two nominal values of feed per minute ft=1m/min and 2m/min. Other machining parameters were as follows: depth of cut ap=5 mm, spindle speed n=9000 r/min and cutting speed vc=350 m/min. The milling process was realized by using a carbide end mill. The results are shown in Figures 5 and 6. Based on the obtained results it was found that the milling process has a significant impact on shortening the manufacturing process. The use of adaptive control allowed for reduction of the processing time by 15 - 24%

    Using CO2 as a coolant in turning process

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    Zastosowanie chłodziwa w procesach obróbkowych ma istotne znaczenie dla przebiegu i wyniku procesu skrawania. Jedną z podstawowych funkcji, jakie spełniają chłodziwa w procesie skrawania, jest redukcja temperatury w strefie skrawania, a przez to m.in. zwiększenie trwałości narzędzia. Z uwagi na uciążliwość dla środowiska naturalnego chłodziw na bazie olejów oraz ograniczone zdolności przejmowania ciepła skrawania stale poszukuje się innych, proekologicznych mediów chłodzących, głównie w postaci gazowej. W związku z tym w artykule przedstawiono wyniki badań zastosowania ciekłego CO2 jako chłodziwa w procesie toczenia stali. Mierzono składowe siły skrawania oraz temperaturę w strefie skrawania. Porównano proces chłodzenia CO2 z obróbką na sucho i z zastosowaniem sprężonego powietrza. W wyniku zastosowania ciekłego CO2 jako chłodziwa uzyskano znaczącą redukcję temperatury oraz składowych siły skrawania.The use of coolant in machining processes is very important for the cutting process and its result. One of the basic functions that coolant perform in the cutting process is the reduction of the temperature in the cutting zone and increasing of tool life. Due to the fact that oil-based coolants are burdensome for the environment and have limited heat transfer capabilities, other pro-ecological cooling fluids are constantly looking for, mainly gases. Taking this into account, the results of studies on the use of CO2 liquid as a coolant in the steel turning process are presented in this paper. Components of the cutting force and the temperature in the cutting zone were measured. Turning processes with the use of the CO2, compressed air and without coolant were compared. As a result of the use of liquid CO2 as a coolant, a significant reduction in temperature and component cutting forces has been achieved

    Grinding wheel wear in Creep-Feed Grinding

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    W artykule przeprowadzono badania jednej z odmian szlifowania, którą jest szlifowanie głębokie z posuwem pełzającym, zwane szlifowaniem CFG (Creep-Feed Grinding). Charakteryzuje się ono dużymi wartościami dosuwu, co powoduje intensywne zużycie ściernicy. Ze względu na to, że jest to szlifowanie jednoprzejściowe i zużycie ściernicy postępujące podczas obróbki ma bezpośredni wpływ na dokładność wymiarowo-kształtową szlifowanej powierzchni, przebadano zużycie promieniowe ściernicy w szlifowaniu CFG stopu Inconel 718. Zakres badań obejmował wpływ posuwu obciągania oraz objętości właściwej zeszlifowanego materiału na wielkość zużycia promieniowego ściernicy. Wykazano, że zużycie promieniowe ściernicy jest zależne głównie od objętości zeszlifowanego materiału. Nie wykazano istotnego wpływu zmiany parametrów obciągania ściernicy.One of the grinding methods is deep grinding with slow feed, called Creep-Feed Grinding (CFG). The CFG process analysed in this paper is characterized by high in-feed values what causes intensive wear of grinding wheel. Due to the fact that it is one-pass grinding, grinding wheel wear during machining has an influence on dimensional and shape accuracy of grinding surface. Taking the above mentioned into account, the experimental study of radial wear of grinding wheel in CFG of Inconel 718 was performed. The influence of the dressing feed and the volume of grinded material on the radial wear of the grinding wheel were determined. It was found that radial wear of grinding wheel mainly depends on the volume of grinded material. The significant effect of the change in parameters of grinding wheel dressing was not revealed

    Metabolic syndrome is associated with similar long-term prognosis in non-obese and obese patients. An analysis of 45 615 patients from the nationwide LIPIDOGRAM 2004-2015 cohort studies

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    Aims We aimed to evaluate the association between metabolic syndrome (MetS) and long-term all-cause mortality. Methods The LIPIDOGRAM studies were carried out in the primary care in Poland in 2004, 2006 and 2015. MetS was diagnosed based on the National Cholesterol Education Program, Adult Treatment Panel III (NCEP/ATP III) and Joint Interim Statement (JIS) criteria. The cohort was divided into four groups: non-obese patients without MetS, obese patients without MetS, non-obese patients with MetS and obese patients with MetS. Differences in all-cause mortality was analyzed using Kaplan-Meier and Cox regression analyses. Results 45,615 participants were enrolled (mean age 56.3, standard deviation: 11.8 years; 61.7% female). MetS was diagnosed in 14,202 (31%) by NCEP/ATP III criteria, and 17,216 (37.7%) by JIS criteria. Follow-up was available for 44,620 (97.8%, median duration 15.3 years) patients. MetS was associated with increased mortality risk among the obese (hazard ratio, HR: 1.88 [95% CI, 1.79-1.99] and HR: 1.93 [95% CI 1.82-2.04], according to NCEP/ATP III and JIS criteria, respectively) and non-obese individuals (HR: 2.11 [95% CI 1.85-2.40] and 1.7 [95% CI, 1.56-1.85] according to NCEP/ATP III and JIS criteria respectively). Obese patients without MetS had a higher mortality risk than non-obese patients without MetS (HR: 1.16 [95% CI 1.10-1.23] and HR: 1.22 [95%CI 1.15-1.30], respectively in subgroups with NCEP/ATP III and JIS criteria applied). Conclusions MetS is associated with increased all-cause mortality risk in non-obese and obese patients. In patients without MetS obesity remains significantly associated with mortality. The concept of metabolically healthy obesity should be revised
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