9 research outputs found
Upravljanje kvalitetom u organskoj proizvodnji i preradi mleka
Organic production of milk and milk products with the mark of 'organic products' requires certain acquaintance of some rules that have been established through the organic production standards. Producers as well as the processors must completly and timely be informed about the necessary conditions and how to manage in accordance with organic production standards. Proper quality managing in farm milk production as well as in the milk processing generate some preconditions for manufacturing of milk products that are more healthy, high nutrition valued, with better flavor properties and which positively influence the sustainable development of the human society, environmental protection and better social quality.Organska poljoprivreda predstavlja sveukupan sistem upravljanja poljoprivredom i proizvodnjom hrane. Kombinovan sa zaštitom životne sredine uz očuvanje biodiverziteta i prirodnih resursa je osnova za kvalitetnu i bezbednu hranu, socijalnu sigurnost i održivi razvoj. U ovom radu istraživanje je skoncentrisano na specijalne teme, tačnije rečeno na bezbednost mleka na farmama koje rade po principima organske proizvodnje, zatim na kvalitet mleka i kontrolu kvaliteta. Sumirani su koraci uvođenja HACCP sistema na porodičnim farmama koje su specijalizovane za proizvodnju sirovog mleka. Kvalitet sirovog mleka je osnovni preduslov za proizvodnju kvalitetnih mlečnih proizvoda a kako je praksa u Srbiji malo drugačija od zahteva EU, njegova važnost će biti još veća posle ulaska u EU. Rezultati istraživanja na oglednim farmama i mlekari u Južnobačkom okrugu (Fruška gora) su dobijeni u okviru projekta BTN 20100. Okolnosti proizvodnje bile su dosta dobre, s obzirom da je područje Fruške gore dosta izolovano i izgleda kao prava prirodna oaza. Nema zagađenja iz okoline, stoka dosta vremena provodi na pašnjacima, rasni sastav je većinom domaće šareno goveče koje je otporno i zdravo, voda je dobrog kvaliteta i ima niz drugih predispozicija za organsku stočarsku proizvodnju. Ova istraživanja imala su nekoliko različitih koraka u upravljanju kvalitetom, od ispitivanja postojećih uslova, zatim ulazak u period konverzije i priprema za organsku proizvodnju
Micropropagation of Endangered and Decorative Species Dianthus pinifolius Sibth. et Sm.
Redundancy problem in writing: From human to anthropomorphic robot arm
This paper presents the analysis of motion of a redundant anthropomorphic arm during the writing. The modeling is based on the separation of the prescribed movement into two motions: smooth global, and fast local motion, called distributed positioning (DP), The distribution of these motions to arm joints is discussed. It is based on the inertial properties and actuation capabilities of joints. The approach suggested allows unique solution of the inverse kinematics of redundant mechanisms such as human arm and anthropomorphic robot arm. Distributed positioning is an inherent property of biological systems, Humans, when writing, as shown in literature and in our earlier work control their proximal joints, while the movement of distal joints follow them (synergy). To enhance capabilities of robots, new control schema are necessary, We show that robot control can be improved if it is biological analog, The major aim of this study is to promote such a hypothesis by using anthropomorphic robot arm in writing as an example
Influence of Thermal Memory on Thermal Piston Model of Photoacoustic Response
In this study, a model of thermoconducting components of the transmission photoacoustic response is analyzed, which includes thermal memory properties of both the examined solid sample and its fluid environment. It is shown that, at low modulation frequencies, lower than minimum among the inverse thermal relaxation time of air, the inverse thermal relaxation time of the sample, and the certain frequency at which the sample is thinner than one-quarter of the wavelength of time-varying temperature perturbation, thermal memory does not affect the photoacoustic response, while, at high frequencies, noticeable effects are observed. These results indicate the possibility of evaluating thermal memory properties of solid samples using classical, transmission, high frequency photoacoustic measurements.16th International Conference on Photothermal and Photoacoustic Phenomena (ICPPP), Nov 27-Dec 01, 2011, Merida, Mexic
Helmholtz Resonances in Photoacoustic Experiment with Laser-Sintered Polyamide Including Thermal Memory of Samples
A minimum volume photoacoustic (PA) cell, employed as an acoustic resonator, is presented. A model of the PA cell transfer function, as a combination of two Helmholtz resonators, is derived. Frequency PA response is described as the product of theoretically derived pressure variation and the transfer function of the PA cell. The derived model is applied to the frequency PA measurements, performed on laser-sintered polyamide. It is shown that the derived model explains the occurrence of resonant peaks in the high-frequency domain ( GT 10 kHz), in both amplitude and phase measurements, obtained by a gas-microphone minimal volume PA cell. The implementation of the model in the growing possibilities of sample characterization using gas-microphone PA cell is discussed
Thermal Diffusivity of High-Density Polyethylene Samples of Different Crystallinity Evaluated by Indirect Transmission Photoacoustics
In this work, thermal diffusivity of crystalline high-density polyethylene samples of various thickness, and prepared using different procedures, was evaluated by transmission gas-microphone frequency photoacoustics. The samples composition analysis and their degree of crystallinity were determined from the wide-angle X-ray diffraction, which confirmed that high-density polyethylene samples, obtained by slow and fast cooling, were equivalent in composition but with different degrees of crystallinity. Structural analysis, performed by differential scanning calorimetry, demonstrated that all of the used samples had different levels of crystallinity, depending not only on the preparing procedure, but also on sample thickness. Therefore, in order to evaluate the samples thermal diffusivity, it was necessary to modify standard photoacoustic fitting procedures (based on the normalization of photoacoustic amplitude and phase characteristics on two thickness levels) for the interpretation of photoacoustic measurements. The calculated values of thermal diffusivity were in the range of the expected literature values. Besides that, the obtained results indicate the unexpected correlation between the values of thermal diffusivity and thermal conductivity with the degree of crystallinity of the investigated geometrically thin samples. The results indicate the necessity of additional investigation of energy transport in macromolecular systems, as well as the possible employment of the photoacoustic techniques in order to clarify its mechanism.18th International Conference on Photoacoustic and Photothermal Phenomena (ICPPP), Sep 06-10, 2015, Novi Sad, Serbi