From Bio-waste to Bone Substitute: Synthesis of Biomimetic Hydroxyapatite and Its Use in Chitosan-based Composite Scaffold Preparation

Nanocomposite structure of the bone can be mimicked by chitosan/hydroxyapatite (CS/HAp) composite scaffold. Biological hydroxyapatite (HAp) contains various ions, which have a crucial role in bone growth. The aim of the present work was to synthesize biomimetic hydroxyapatite and prepare composite scaffolds based on chitosan, where HAp was synthesised from hen eggshells, seashells and cuttlefish bone. The powders were composed of nano-structured calcium deficient HAp and amorphous calcium phosphate (ACP). In the as-prepared powders, Sr2+, Mg2+ and Na+ ions were detected as a result of using biogenic precursor of Ca2+ ions. Highly porous CS/HAp structures have been prepared by freeze-gelation technique. The CS/HAp scaffolds have shown highly porous structure with very well interconnected pores and homogeneously dispersed HAp particles. The MTT assay of CS/HAp scaffolds has shown no toxicity, and the live/dead assay has confirmed good viability and proliferation of seeded cells. This work is licensed under a Creative Commons Attribution 4.0 International License

Modern design and control of automatic transmission and the prospects of development

Rad predstavlja pregled savremenih tehničkih rešenja automatske transmisije u automobilskoj industriji sa pogledom na njihov uticaj na održivi razvoj. Cilj prvog dela rada je strukturalni prikaz specifičnih konstrukcija i sistema upravljanja koji su danas u upotrebi kod automatske transmisije, sa naglaskom na implementaciju mehatronike. Drugi deo je zasnovan na perspektivi razvoja, integrisanjem nekoliko grana 'soft computing'-a, kao što su fazi logika i veštačka neuronska mreža sa ciljem stvaranja optimalnog kontrolnog algoritma za dobijanje doprinosa u smanjenju potrošnje goriva, izduvne emisije, povećanje komfora i performansi vozila.The paper provides an overview of modern technical solutions of automatic transmissions in automotive industry with their influence on sustainable development. The objective of the first section is a structural view of specific constructions and control systems of presently used automatic transmissions, with emphasis on mechatronics implementation. The second section is based on perspectives of development, by integrating some branches of soft computing, such as fuzzy logic and artificial neural networks in order to create an optimal control algorithm for obtaining a contribution to fuel economy, exhaust emission, comfort and vehicle performance

Modern design and control of automatic transmission and the prospects of development

Rad predstavlja pregled savremenih tehničkih rešenja automatske transmisije u automobilskoj industriji sa pogledom na njihov uticaj na održivi razvoj. Cilj prvog dela rada je strukturalni prikaz specifičnih konstrukcija i sistema upravljanja koji su danas u upotrebi kod automatske transmisije, sa naglaskom na implementaciju mehatronike. Drugi deo je zasnovan na perspektivi razvoja, integrisanjem nekoliko grana 'soft computing'-a, kao što su fazi logika i veštačka neuronska mreža sa ciljem stvaranja optimalnog kontrolnog algoritma za dobijanje doprinosa u smanjenju potrošnje goriva, izduvne emisije, povećanje komfora i performansi vozila.The paper provides an overview of modern technical solutions of automatic transmissions in automotive industry with their influence on sustainable development. The objective of the first section is a structural view of specific constructions and control systems of presently used automatic transmissions, with emphasis on mechatronics implementation. The second section is based on perspectives of development, by integrating some branches of soft computing, such as fuzzy logic and artificial neural networks in order to create an optimal control algorithm for obtaining a contribution to fuel economy, exhaust emission, comfort and vehicle performance

TRAJNA ZAŠTITA ISTARSKOG GOVEDA GOSPODARSKIM KORIŠTENJEM

Istrian cattle is the most numerous autochtonous breed of cattle in Croatia. It represents a vivid monument of time and climate, well provided together by breeders and wider community for allmoust two decades. Negative movements in the population of Istrian cattle caused by global trends in animal production of economically developed societies has been stoped. Actual population of of Istrian cattle is in the phase of recovery and mild stagnation. Reduced further growth of population is conditioned by the lack of verified economic reafirmation which needs to conect interests between breeders and consumers, ensuring in that way the sustainability of the breed. The project of reafirmation of the Istrian cattle, allready underway, through the production programme of "Meat of Istrian cattle" has initialized the consensus of all subjects in the sequence of the food-stuff (breeding, processing, gastronomy) and it gives first positive results.Istarsko govedo najbrojnija je autohtona pasmina goveda u Hrvatskoj. Predstavlja živi spomenik vremena i podneblja o kojem gotovo dva desetljeća brinu vrijedni uzgajivači i šira društvena zajednica. Zaustavljena su negativna kretanja u populaciji istarskog goveda izazvana globalnim trendovima u animalnoj proizvodnji gospodarski razvijenijih društava, a aktualna populacija nalazi se u fazi oporavka i blage stagnacije. Usporavanje daljnjeg rasta populacije uvjetovano je izostankom provjerene gospodarske reafirmacije koja treba interesno povezati uzgajivače i potrošače, osiguravajući time samoodrživost pasmine. Pokrenuti projekt reafirmacije istarskog goveda kroz program proizvodnje \u27\u27Mesa istarskog goveda\u27\u27 potakao je konsenzus svih subjekata u slijedu namirnice (uzgoj, procesing, gastronomija), te daje prve pozitivne učinke

Is the Stack Distance Between Test Case and Method Correlated With Test Effectiveness?

Mutation testing is a means to assess the effectiveness of a test suite and its outcome is considered more meaningful than code coverage metrics. However, despite several optimizations, mutation testing requires a significant computational effort and has not been widely adopted in industry. Therefore, we study in this paper whether test effectiveness can be approximated using a more light-weight approach. We hypothesize that a test case is more likely to detect faults in methods that are close to the test case on the call stack than in methods that the test case accesses indirectly through many other methods. Based on this hypothesis, we propose the minimal stack distance between test case and method as a new test measure, which expresses how close any test case comes to a given method, and study its correlation with test effectiveness. We conducted an empirical study with 21 open-source projects, which comprise in total 1.8 million LOC, and show that a correlation exists between stack distance and test effectiveness. The correlation reaches a strength up to 0.58. We further show that a classifier using the minimal stack distance along with additional easily computable measures can predict the mutation testing result of a method with 92.9% precision and 93.4% recall. Hence, such a classifier can be taken into consideration as a light-weight alternative to mutation testing or as a preceding, less costly step to that.Comment: EASE 201

EFFECT OF FAMILY FARM SIZE, SEASON AND FEEDING MANAGEMENT ON PRODUCTION AND MILK QUALITY

Obiteljska poljoprivredna gospodarstva u Hrvatskoj su različita po strukturnim, organizacijskim i socijalnim značajkama. Dosadašnja istraživanja ukazala su na nisku razinu proizvodnje i dohodovnosti na većini obiteljskih poljoprivrednih gospodarstava koja se bave proizvodnjom mlijeka. Njihov razvoj i struktura ne zadovoljavaju uvjete pravog tržišnog gospodarstva, te su za prijelaz u ozbiljne uvjete tržišnog gospodarenja, potrebne velike promjene u strukturi, organizaciji, proizvodnji, upravljanju i poslovanju gospodarstava. Cilj rada je utvrđivanje utjecaja veličine poljoprivrednog gospodarstva na proizvodnju i kvalitetu tržno isporučenog kravljeg mlijeka, te primjerenost hranidbe kroz sadržaj uree u mlijeku. Istraživanje je obuhvatilo dvanaest obiteljskih gospodarstava koja se bave proizvodnjom mlijeka, a praćenje je provedeno tijekom 2005. godine. Na velikim i srednjim obiteljskim gospodarstvima uočen je trend povećanja proizvodnje mlijeka, dočim je na malim obiteljskim gospodarstvima uočena stagnacija količine tržno isporučenog mlijeka. Velika i srednja obiteljska gospodarstva isporučuju mlijeko bolje tržne kvalitete. Najveći sadržaj masti u mlijeku zabilježen je na malim obiteljskim gospodarstvima. Utvrđena razina utjecaja sezone na sadržaj masti u mlijeku je statistički signifikantna. Utjecaj veličine gospodarstva i sezone na sadržaj bjelančevina u mlijeku signifikantne je razine (P<0,01). Utvrđeni utjecaj veličine gospodarstva i managementa hranidbe na broj somatskih stanica u mlijeku statistički je signifikantan (P<0,01). Utjecaj managementa hranidbe na broj mikroorganizama u mlijeku je statistički signifikantan (P<0,05). Dinamika promjene sadržaja uree u mlijeku ukazuje na određene sezonske manjkavosti obroka u pogledu udjela bjelančevina i energije.Family dairy farms in Croatia differ in structural, organizational and social characteristics. The past researches have indicated the low level production and profits on most of the family farms oriented to milk production. Their development and structure do not meet the requirements of the actual market economy, and for their transit to serious market economy, big changes in the structure, organization, production, management and farm economy are needed. The aim of this study was to establish the effect of family dairy farm size on the production and quality of market delivered cows milk, and the adequacy of feeding by the concentration of urea in the milk. The research included twelve family farms oriented to milk production and the observation was carried out during 2005. Milk fat and proteins content was determined by infrared spectrophotometry, the number of somatic cells by fluoro-opto-electronic method, urea concentration by spectrophotometry modified Berthelot method, and the number of microorganisms by epifluoroscent free citometry. The trend of increased milk production was observed on big and medium family farms, but on small family dairy farms stagnation of quantity market delivered milk was observed. Big and medium family dairy farms deliver better quality milk to the market. The highest content milk fat was determined on small family farms. The determined level of season influence on milk fat content was significant. The influence of dairy farm size and seasons on milk protein content was also significant (P<0.01). The determined effect of dairy farm size and feeding management on the number of somatic cells in the milk was significant (P<0.01). The effect of feeding management on the number of microorganisms in the milk was significant (P<0.05). Dynamics of urea change concentration in the milk in the observed period indicates specific seasonal ration inadequacies regarding protein contents and also the insufficient energy intake. On the big family dairy farms the most acceptable quality of the voluminous forages and the urea concentration was established indicating better balanced rations