bluuebunny/crossref_metadata_2025 huggingface dataset:
Razvoj podeželske gastronomske destinacije z lokalno dodano vrednostjo
Authors: Lešnik Štuhec Tanja
Published: March 2021

Gastronomski turizem je lahko pomembno orodje sonaravnega razvoja in trženja podeželskih destinacij. Sistematičen razvoj podeželja temelji na dolgoročni usmeritvi in sliki prihodnosti destinacije, ki vključuje in s katero se istovetijo vsi deležniki. Samo povezani lahko doprinesejo k celovito usklajeni ponudbi, ki s sodobnimi trženjskimi orodji nagovarja prepoznane ciljne skupine gostov. Ključno vlogo igra koordinator mreženja ponudnikov in trženja atraktivne, visokokakovostne ponudbe z veliko lokalno dodane vrednosti. Ta temelji na prepoznanih živilih, gradivih, postopkih pridelave in predelave ter odličnih chefih, ki v kratkih dobavnih verigah zagotavljajo prvinske okuse na poti od njive do krožnika. Pomreženi strokovno usposobljeni in inovativni ponudniki lahko sistematično gradijo celovito kakovost destinacije, izpostavljajo gastronomske značilnosti in poreklo prostora ter vzpostavljajo specializirano okolje, prijazno za gastronomski oddih daleč od stresnega sveta. Mir, tišina, čist zrak in voda, lepa krajina, ohranjena narava, ponudba z zeleno zgodbo, prijazni domačini, narečja, šege in navade, ki se kažejo tudi skozi odlično gastronomijo, kreativne delavnice, druženja in gastronomske prireditve, omogočajo ob programih dobrega počutja v naravi in podeželskem velnesu neponovljiva doživetja ljubiteljem hrane in vsem, ki si vzamejo čas in so tovrstna gastronomska doživetja pripravljeni tudi plačati. To je smer, ki jo je izbrala Slovenija, ki bo v letu 2021 gastronomska regija Evrope.
Certificirani kmetijski izdelki in živila ter kolektivne blagovne znamke
Authors: Borec Andreja , Robačer Martina
Published: March 2021

V današnjem času strožje zakonodaje glede varnosti in kakovosti hrane je opazen porast različnih shem kakovosti in certifikatov za kmetijske pridelke in živila. Za lokalne kmetijske pridelke so poleg različnih shem kakovosti zanimive tudi kolektivne blagovne znamke s certifikatom. Med njimi obstajajo pomembne razlike, vendar vse same po sebi še nujno in neposredno ne zagotavljajo višjega dohodka za kmetijsko gospodarstvo. Pri proučevanju in ugotavljanju vpliva različnih certificiranih izdelkov na razvoj podeželja je pomembno, da upoštevamo kvalitativni in kvantitativni pristop.
Kmetijski proizvodni sistemi v spreminjajočem se svetu
Authors: Borec Andreja
Published: March 2021

Povečanje proizvodnje hrane v obdobju zelene revolucije je posledica znanstvenega napredka, novih tehnologij in mehanizacije, razvoja novih sort poljščin, uporabe pesticidov in gnojil ter gradnje velikih namakalnih sistemov; rezultat tega pa znatno povečanje proizvedenih kalorij na hektar. Višja proizvodnja nujno ne pomeni tudi povezovanja vseh prednosti intenzivnega kmetijstva. Danes so kritike zelene revolucije številne: pregled številnih študij je pokazal, da je le-ta povzročila neuravnotežene koristi in povečala neenakost dohodka. Zato sedanji kmetijski sistemi potrebujejo temeljito preobrazbo z vidika okoljskega, socialno-ekonomskega in tudi zdravstvenega stanja ljudi. Sedanja družba je torej pred pomembno nalogo: združiti najnovejše tehnologije, omogočiti participativne modele odločanja in obravnavati kmetijske sisteme kot kmetijske ekosisteme.
Vpliv obdelave tal na talno bioto in sekvestracijo ogljika
Authors: Muršec Mateja
Published: March 2021

Različne tehnike obdelave tal različno učinkujejo na ekosistemske storitve tal, med drugimi tudi na biodiverziteto in življenjske procese v tleh s tem, da vplivajo na regulacijo vode, zraka, toplote in razporeditev hranil v tleh. V kmetijstvu je cilj razviti sistem pridelavo hrane, ki je trajnosten ter ekonomičen iz vidika potrošnika in pridelovalca, hkrati pa naj ne bi dopuščal nadaljnje degradacije tal. Z namenom omiliti globalno segrevanje in izboljšati kakovost zraka in vode ter ohranjati kakovost (kmetijskih) tal, je danes pri obdelavi tal pomembno upoštevati tudi sekvestracijo oz. zadrževanje ogljika v tleh. Zaloga talnega ogljika je namreč zelo dovzetna za različne obdelave tal oz. za sisteme pridelave hrane. Takšne cilje si je zastavila ohranitvena obdelava tal, ki se je po svetu opazno razširila v devetdesetih letih prejšnjega stoletja. V Sloveniji (kot tudi v večini evropskih držav), kjer še vedno prevladuje tradicionalni način obdelave tal z oranjem (konvencionalna obdelava tal), se ohranitvena obdelava tal počasi uveljavlja tudi v zadnjih nekaj letih. Oba načina obdelave tal se razlikujeta predvsem v intenzivnosti in številu mehanskih posegov, v deležu pokritosti tal z rastlinskimi ostanki in v raznovrstnosti vegetacije.
Vzpostavitev lokalnega trga malih kmetijskih pridelovalcev s strategijo razvoja turističnih destinacij
Authors: Zdrilić Ivica
Published: March 2021

Kmetije malega obsega močno čutijo vpliv globalizacije, ne samo zaradi večje konkurence na trgu prehranskih izdelkov, temveč tudi zaradi povezanosti s turizmom, ki je trenutno v fazi velikih sprememb. Da bi lahko izkoristili sinergijski učinki turizma in kmetijstva, morajo mali kmetijski pridelovalci aktivnosti usmeriti v prepoznavnost lastnih pridelkov in razvijati lastne turistične potenciale. S tem se zagotovijo pogoji uspešnega poslovanja, ohranja se kmetijska pridelava in delovna mesta, ustvarjajo se izdelki z dodano vrednostjo. Pri tem imajo pomembno vlogo izdelki z označbami kakovosti.
Sensorial character of beer dry hopped with new Czech genotypes of hops with a specific flavor
Authors: Straková Lenka , Nesvadba Vladimír , Křivánek Jindřich , Slabý Martin , Vrzal Tomáš , Charvátová Jitka , Cerkal Radim , Olšovská Jana
Published: March 2021

In the Czech Republic breeding of new hop varieties is traditionally performed. Its properties correspond with the requirements and interests of end users, in particular hop growers, brewers and especially beer consumers, who with an increasing favor taste new types of beer. The study presents 8 new promising aromatic genotypes, whose major part (Uran, Juno, Ceres, Jupiter, Eris and Most) is already in the registration process of ÚKZÚZ of the Czech Republic (Central Institute for Supervising and Testing in Agriculture CISTA). The tested genotypes were described using brewing tests. Regarding the character of the tested hop varieties, there was chosen a uniform and simple infusion recipe with a top fermentation and dry hopping. The final beer samples were evaluated using chemical and sensorial analyses focusing on a hop aroma. All beer samples were rated as very good, the overall impression of the samples on the scale of 1 to 9 ranged from 2.9 to 3.1. The hop aroma and also bitterness character of the final beer samples were evaluated of high quality. Depending on the hop profile of the beer samples, there were suggested beer styles where the given varieties can be successfully used. These results indicate a high potential of these varieties for the use in brewing practice. Finally, the probability of perceiving a particular hop aroma in beer given by perceiving the aroma in hops was determined by Bayes’ theorem. It was found that probability particularly for spicy, resinous, herbal, citrusy, floral, fruity and grassy aroma was 100, 100, 100, 40, 38, 43, and 100%, respectively.
Evaluation of malting quality of spring barley genetic resources from different regions of origin
Authors: Zavřelová Marta , Psota Vratislav , Matušinsky Pavel , Musilová Markéta , Némethová Michaela
Published: March 2021

A set of 92 genetic resources of spring barley split into groups according to the areas of origin was studied in terms of grain malting quality. The following malting parameters were monitored in this study: nitrogen content in barley grain, malt extract, relative extract at 45 °C, Kolbach index, diastatic power, apparent final attenuation, friability, β-glucans in wort, haze of wort measured at the angles of 15° and 90°. In the studied set, the largest variability was found in the haze of wort (90°), the smallest in the apparent final attenuation. The optimal values of the extract content in the malt dry matter according to the malting quality index were only detected in the genotypes originating from Europe. The group of the genetic resources from South America and Australia, together with the genotypes from the Middle East and Africa, differed statistically significantly in the values of the Kolbach index from other groups. The two-row genotypes differed statistically significantly in the values of the malt extract content, relative extract at 45 °C, Kolbach index, diastatic power, friability and β-glucan content in wort. Although the European and non-European groups differed in a number of traits, the non-European groups also included genetic resources that in their malting parameters approached or equaled the European malting varieties (such as Psaknon). In this study, several significant correlations were found; the strongest correlations were between friability and malt extract (r = 0.85), friability and Kolbach index (r = 0.84).
Perceived Benefits and Barriers to Prenatal and Postpartum Exercises Among Child Bearing Women in Kano, Nigeria
Authors: Rajah Amina Suleiman , Bayero Umar Bilkisu , Hussein Zainab Muhammad , Lawal Auwal Khadija , Tashi Tijjani Faiza , Tukuntawa Abdulaziz Sulaiman , Rabiu Abdullahi Fatima
Published: March 2021

BACKGROUND

Pregnancy is a stressful phenomenon experienced by women, during which the body experiences dramatic anatomical, physiological, and psychological changes.

AIM

The study examined perceived benefits and barriers to prenatal and postpartum exercises among pregnant women in Kano.

METHODS

The study was a descriptive survey in which 400 consenting pregnant women attending antenatal clinic were recruited for a period of 3 months (November 2019 to January 2020, using systematic random sampling technique. A structured interviewer-administered questionnaire was utilized to elicit responses and the data obtained was analyzed using descriptive statistics of mean, standard deviation, and frequency distribution.

RESULTS

Findings showed that the respondents have a mean age of 26.86 ± 5.4 years which ranges from 17–47 years. Prenatal exercises may be associated with the prevention of excessive weight gain and/or gestational diabetes and/or preeclampsia. The study further revealed that most of the respondents agreed that postpartum exercises prevents vaginal and uterine prolapse and urinary incontinence, helps in losing post pregnancy body weight and prevents diastasis recti abdominis. The major barriers identified included lack of access to facilities, lack of family support, and cultural factors.

CONCLUSION AND RECOMMENDATION

The study concludes that there is a positive perception of the benefits of prenatal and postpartum exercises and therefore, recommends that maternity care givers should provide accurate, adequate, and relevant information and advocate increased social and family support.
Waiting as Performative and Relational: A Narrative Inquiry Study Into the Experiences of Women Who Use Substances
Authors: Dewart Georgia , Estefan Andrew , Clandinin D. Jean , Caine Vera
Published: March 2021

Background and Purpose

The act of waiting in health care is becoming increasingly prevalent worldwide. Waiting in health care is not a neutral activity; it is filled with expectations marked by cultural and social norms. In this article, we consider the performative nature of waiting by reflecting on the experiences of two participants in a narrative inquiry study.

Methods

Drawing on a narrative inquiry study focused on the experiences of three women who disclosed illegal substance use during their pregnancy or early postnatal period, we inquired into two participants' experiences of waiting. The study which took place in a large urban center in Western Canada, where the researcher connected with participants who faced numerous challenges due to poverty, stigma, and discrimination.

Results

Sharing the narratives of Georgia Dewart, and participants Renate, and Marilynn, we explore the performative act of waiting in their interactions with health care. We consider the political and social implications of the act in order to explore the subtleties and overlooked consequences of waiting. This work encourages the nursing profession to address overlooked aspects of care, such as the act of waiting.

Implications for Practice

Our findings draw attention to the normative expectations within participants' experiences of waiting. This work offers methodological considerations for those engaging with Butler's concept of performativity when considering everyday acts. We also challenge care providers to reflect on their experiences working with clients, families, and communities to consider both the relational and performative nature of these interactions.
PEMILIHAN BAHASA PADA MASYARAKAT ETNIK JAWA DI DUSUN GUMUK BANJI, DESA KENCONG, KECAMATAN KENCONG, KABUPATEN JEMBER
Authors: Nurfadila Yastin , Sariono Agus , Hariyadi Edy
Published: March 2021

The Gumuk Banji community is a multi-ethnic society (consisting of Javanese, Madurese, and Chinese ethnic) and a bilingualist society (who masters Javanese, Madurese, and Indonesian). In a bilingualism society, there is always the problem of language choice because each language variety has its own function in the community. This article aims to describe the form of language choice and explain the determinants of language choice in the Javanese ethnic community in Gumuk Banji Village. The study was conducted using qualitative methods. Data collected by questionnaire and interview. The sample is determined by purposive random sampling technique. Data analysis was carried out in three stages: (1) data reduction, (2) data presentation, and (3) conclusion / verification. Data collected by questionnaire and open interview. The data interpretation stage is carried out using context analysis of the speech component. The results are stated as follows. The language varieties chosen in the family domain successively from the highest to the lowest frequency are the Javanese variety of ngoko, the Javanese variety of manners, and Indonesian; in the realm of neighborhoods: Javanese with a variety of ngoko, Javanese with a variety of manners, Madura with a variety of languages, and Indonesian; and in the realm of transactions: the Javanese variety of ngoko, the Javanese variety of manners, the Madurese variety of languages, and Indonesian. The factors that determine language selection in the family domain are participant factors (kinship status), speech objectives, speech media, and speech situations (formal or informal situations); in the neighboring domain are participant factors (ethnic similarities or differences, age and social status factors, and social relations factors), and the situation of speech (formal and informal), and in the domain of transactions are participant factors (ethnic similarities or differences).
HEATHCLIFF’S SELF ACTUALIZATION IN WUTHERING HEIGHTS BY EMILY BRONTE
Authors: Fatmawati Ririn
Published: March 2021

This research discusses about Heathcliff’s Self-Actualization in Wuthering Heights written by Emily Bronte which is set in the Yorkshire moors of Northern England. The inductive method is used to make the discussion of the topic brief. It means that the analysis starts from the specific concept goes to general conclusion. The data used in this thesis are collected by library research. This article also applies Maslow’s Hierarchical Theory of motivation. There are five hierarchies of needs which have to be fulfilled before someone goes through to accomplish self actualization, those are physiological needs, safety needs, belongingness and love needs and the last needs are self-esteem needs. This article focuses on how Heathcliff fulfil his psychological need, how he get his safety need, how he get the belongingness and love need, how he reach his self-actualization.

. The research is to find Heathcliff succeeded to complete his self actualization in Wuthering Heights. Heathcliff can achieve his self-actualization because he wants to become a total kind of person to reach his dream whatever way he has done.  He is able to unify Wuthering Heights and Thrushcross Grange, and making Hareton as slave.
STRATEGI TINDAK TUTUR JURU BICARA TIM KAMPANYE NASIONAL DALAM ACARA “DUA ARAH” DI KOMPAS TV
Authors: Hasin Ikromal , Sofyan Akhmad , Hariyadi Edy
Published: March 2021

Presidential Election is a democratic party to elect new leaders. A spokesperson is needed to attract the public to choose the candidate pairs who compete to win the party. A spokesperson for TKN-Jokowi's National Campaign Team (Indonesian: Tim Kampanye Nasional) is one example of a spokesperson who carried out this task. This article aims to discuss the national campaign team's speech acts strategy in Kompas TV program entitled "Dua Arah". The researcher will categorize articulation carried out by the spokesperson of TKN into four types of speech works: persuasive, defending, attacking, and challenging. The data analysis method used analyses speech based on the specified categories in speech acts, presuppositions, implicatures, cooperative principles, and the principle of manners found in the address based on the context of the talk. The results showed that the spokesperson for the TKN placed persuasive action in the first position, fending effort in the second position, attacking movement in the third position, and challenging activities in the last part. Convincing story at the first position aims to attract the people's sympathy to choose Jokowi-Ma'ruf Amin with the most utterances telling Jokowi's government program's success. The challenging action in the last position contains a request to the spokesman of BPN-Prabowo's election campaign team (Indonesian: Badan Pemenangan Nasional) to do something and explain their statement in detail.
Infezione da HIV e popolazione straniera: necessità di un SSN realmente inclusivo.
Authors: Testa Jacopo , al. et
Published: March 2021

La pandemia da SARS-CoV-2 ha evidenziato nuovamente come le malattie infettive interessino l’intero tessuto sociale, colpendo maggiormente le classi più fragili, tra cui i migranti, spesso difficili da raggiungere da parte dei servizi.
Le infezioni croniche virali (epatiti ed HIV) sono epidemiologicamente più rilevanti nella popolazione migrante per una maggiore incidenza nelle aree geografiche di provenienza e per la presenza di determinanti di rischio sociali, comportamentali o abitativi nei paesi d’arrivo o durante il percorso migratorio. La diagnosi precoce attraverso programmi di screening e la garanzia di trattamento sono elementi essenziali per ridurre l'impatto dell'infezione da HIV. La salute delle comunità migranti, attraverso la promozione di sistemi sanitari realmente inclusivi, è indissolubilmente legata al benessere e alla salute pubblica di tutti nei paesi d’arrivo. In Italia nonostante un miglioramento del livello di integrazione della popolazione migrante, la fruizione delle risorse sanitarie rimane spesso inadeguata, soprattutto in termini di programmi di screening e prevenzione, con conseguenti divari nell'incidenza delle patologie e loro esiti. La legge italiana garantisce inclusione, ma nella realtà si riscontrano innumerevoli criticità di applicazione, con una notevole disparità a seconda delle varie realtà locali. I decisori di politiche sanitarie dovrebbero prendere in considerazione queste problematiche, in particolare nei prossimi, delicati mesi di gestione della pandemia e di diffusione dei vaccini, per garantirne un accesso equo per le fasce più vulnerabili, inclusi i soggetti migranti affetti da HIV.
Optimization of rule-based energy management strategies for hybrid vehicles using dynamic programming
Authors: Zhu Di , Pritchard Ewan , Dadam Sumanth Reddy , Kumar Vivek , Xu Yang
Published: March 2021

Reducing energy consumption is a key focus for hybrid electric vehicle (HEV) development. The popular vehicle dynamic model used in many energy management optimization studies does not capture the vehicle dynamics that the in-vehicle measurement system does. However, feedback from the measurement system is what the vehicle controller actually uses to manage energy consumption. Therefore, the optimization solely using the model does not represent what the vehicle controller sees in the vehicle. This paper reports the utility factor-weighted energy consumption using a rule-based strategy under a real-world representative drive cycle. In addition, the vehicle test data was used to perform the optimization approach. By comparing results from both rule-based and optimization-based strategies, the areas for further improving rule-based strategy are discussed. Furthermore, recent development of OBD raises a concern about the increase of energy consumption. This paper investigates the energy consumption increase with extensive OBD usage.
The model of combustion process in the marine 4-stroke engine for exhaust gas composition assessment
Authors: KOWALSKI Jerzy
Published: March 2021

The paper presents the model of combustion process in the marine, turbocharged, 4-stroke and Diesel engine. The main target of modeling is the assessment of the exhaust gas composition. Presented multi-zone, 3-D model of combustion process consists of the following sub-models of processes: the fuel injection, the brake-up and the evaporation of fuel and the turbulence flow and the heat transfer phenomena. Presented model basis on the 3Z-ECFM mechanism of combustion and the initial and boundary conditions collected during direct measurements. The positive validation of the calculation results are obtained for mean and maximum value of the combustion pressure and values of oxygen and nitric oxides fractions in the exhaust gas. Unfortunately, fractions of carbon compounds in the exhaust gas are not properly calculated.
Trends in automotive emissions, fuels, lubricants, legislation and test methods –a global view, with a focus on the EU & US–Summary of the 5th International Exhaust Emissions Symposium (IEES)
Authors: Bielaczyc Piotr , Woodburn Joseph , Gandyk Mateusz
Published: March 2021

The field of vehicular exhaust emissions is experiencing wide-ranging and rapid changes. Air quality is very high on the political agenda and pressure remains to limit and reduce greenhouse gas emissions from the road transport sector. In addition to limits being increasingly stringent, the list of parameters subject to legal limits are slowly expanding – and, most importantly, these limits must be met under a wide wide range of conditions. A range of strategies are available to overcome these difficulties, which was explored during the 5th International Exhaust Emissions Symposium (IEES) hosted at BOSMAL in May 2016. This paper reports and summarises the topics of the 5th IEES and attempts a synthesis on the current status of the field and what the coming years may hold for the automotive and fuel industries and other allied fields.
Diagnosing methods common rail fuel injectors
Authors: OSIPOWICZ Tomasz , ABRAMEK Karol Franciszek
Published: March 2021

Article describes diagnose and research methods Common Rail system fuel injectors. Professional diagnose modern fuel injectors is very difficult procedure. Basic theirs work parameter influencing on correctly work parameters are magnitude injection and return dosages by definite pressures prevailing in system and injection times. Sometimes dosages during diagnose by coordinate task and actual fuel injector are correct but engine work is not proper. So that during diagnose should extend tests procedure in range varies work conditions. Fuel injectors work characteristics are one of method researching in whole range work. During researches has been used Continental fuel injector.
Causes of the powerplants failures installed on Polish civil aviation aircraft
Authors: BALICKI Włodzimierz , GŁOWACKI Paweł
Published: March 2021

Currently in Poland about 2,500 different engine types are installed on the aircraft. In the years 2008-2016 powerplants failures caused nearly 600 aviation events. Aborted flight or emergency landing, especially in the case of aircraft powered by a single piston engine occurred. The objective of the article was to determine the failure causes and assessment of their impact on the flight safety. Engine faults were assigned to particular types of powerplants, for example turboshaft, piston, etc. Causes of the failures were examined, assigning ATA chapter to each of them. Also human factor was taken into account. According to the ICAO methodology, aviation safety engine systems essential for flight safety and theirs impact on the safety risk was determined. The results of the analyzes presented in this article are useful for managing the national aviation safety and supervising SMS in aviation organizations. The article shows that preventive measures to raise the level of aviation safety should be taken. This is the first comprehensive analysis of the powerplants failure causes and an evaluation of their influence on the level of aviation safety in Poland.
Emission of pollution from motor vehicles with respect to selected solutions of roundabout intersections
Authors: JAWORSKI Artur , LEJDA Kazimierz , MĄDZIEL Maksymilian
Published: March 2021

The article concerns the assessment of emmision of selected two-lane roundabout functioning in the city of Rzeszow and its alternate turbo version. In the work was considered four scenarios that represent two different in terms of traffic congestion time of day. The results of the emission of selected components of the exhaust gas (NOx and particulates PM10) were obtained on the basis of calculations of emission model VERSIT+ Enviver. While the input data for the calculations were taken from the modeled options of roundabouts in the Vissim program. The results from the Enviver program were compared to calculations from mesoscopic model COPERT 5. The results show that the overall reduction in average speed, as well as increased frequency of braking and sudden acceleration, directly contribute to the growth of harmful emissions. However, with respect to comparision of turbo roundabout in regard of currently running two-lane roundabout can be observed reduction of selected components of exhaust gases emission about approx. 1/3.
Diesel engine for aircraft propulsion system
Authors: GĘCA Michał , CZYŻ Zbigniew , SUŁEK Mariusz
Published: March 2021

Stricter requirements for power in engines and difficulties in fueling gasoline engines at the airport make aircraft engine manufac-turers design new engines capable of combusting fuel derived from JET-A1. New materials used in compression-ignition engines enable weight reduction, whereas the technologies of a Common Rail system, supercharging and 2-stroke working cycle enable us to increasethe power generated by an engine of a given displacement. The paper discusses the parameters of about 40 types of aircraft compression ignition engines. The parameters of these engines are compared to the spark-ignition Rotax 912 and the turboprop. The paper also shows trends in developing aircraft compression-ignition engines.
Investigations of the influence of engine thermal state on the fuel consumption of passenger vehicles
Authors: ADAMSKI Wojciech , POLAK Stanisław
Published: March 2021

The paper presents the results of investigations of the fuel consumption of two vehicles performed for non-stabilized engine temperature in the start and warm up phases. The measurements were performed in a wide range of ambient temperatures from –18°C to +25°C. In order to obtain such conditions the tests were carried out in a climate chamber.
Concept of the exhaust system of combustion engines used in underground mining
Authors: LESIAK Krzysztof , BRZEZANSKI Marek
Published: March 2021

Analyses the problems occurring in the exploitation combustion engines used in mining have been presented in article. Design solutions used at present to protect the intake and exhaust systems of internal combustion engines operated in underground hard coal mines have been also described. A new design concept of exhaust system have been presented.
Analysis of air flow velocity distribution in the intake system of an SI engine
Authors: KOŁODZIEJ Szymon , LIGUS Grzegorz , MAMALA Jarosław , AUGUSTYNOWICZ Andrzej
Published: March 2021

The conditions of air flow in the intake determine power generated by the engine to a large extent. The biggest resistances in flow of the air sucked or pumped into the engine are generated by the throttle, which is at the same time the main component which allows for regulation of engine power. For the purpose of research conducted in this work, time density of engine work points in analyzed velocity profiles was determined with the use of Engine Road Load Simulator. Thanks to the knowledge of time velocity, it was possible to determine throttle positions at which the engine operates most frequently. With the use of image analysis methods, obtained parameters were experimentally researched, considering flow disturbances which are the effect of air flow through the throttle and uneven air distribution in the intake manifold of a four-cylinder engine.
Effect of the boost pressure on basic operating parameters, exhaust emissions and combustion parameters in a dual-fuel compression ignition engine
Authors: LUFT Sławomir , SKRZEK Tomasz
Published: March 2021

The dual-fuel engine enables application of various fuels. One of such fuels is propane or its mixture with butane (LPG). Application of such fuels results in reduction of engine operation costs. The paper presents effect of application of such fuel in a turbocharged dualfuel engine on basic operating parameters, exhaust emissions and basic combustion parameters. Test results in the form of load characteristics for various boost ratios obtained for dual-fuel engine were compared to corresponding results obtained for conventional engine operating on diesel fuel only. The obtained results indicate that it is possible a dual-fuel operation with the propane energy share of 70% for maximum engine loads.
Comparative studies of exhaust emission from diesel engine fuelled with diesel fuel and B100 fuel
Authors: KRUCZYNSKI Stanisław , ŚLĘZAK Marcin , GIS Wojciech , ŻÓŁTOWSKI Andrzej , GIS Maciej
Published: March 2021

The article presents a comparative study of carbon monoxide, hydrocarbons, nitrogen oxides and the mass and number of particulate of diesel engine fulled with diesel and B100. B100 is a biofuel produced from vegetable oils for vehicles with compression-ignition engines. B100 fuel and diesel have similar physical-chemical characteristics which have been analyzed. The research was carried out on an engine dynamometer in four cycles: ESC, ETC, WHSC and WHTC. The article provides an analysis of the research results, preceded by a discussion of the test cycles used.
Studies of energy use by electric buses in SORT tests
Authors: GIS Wojciech , KRUCZYŃSKI Stanisław , TAUBERT Sławomir , WIERZEJSKI Andrzej
Published: March 2021

In article the market for electric buses in the world and in Poland have been discussed. The test methods for energy consumption of citi buses in Poland and the appropriate measuring devices have been presented. The article presents the results of the energy consumption of the citi bus in the test SORT 2. The results obtained were referred to results in the case other electric and conventional buses.
Evolution of national annual pollutant emission from motor vehicles in Poland
Authors: BEBKIEWICZ Katarzyna , CHŁOPEK Zdzisław , SZCZEPAŃSKI Krystian , ZIMAKOWSKA-LASKOWSKA Magdalena
Published: March 2021

The work analyses the national annual emission of pollutants from passenger cars in Poland, in the years 2000–2015, including the classification of combustion engines relative to the ignition system. The study was carried out in accordance with the methodology used in the COPERT 4 software. The vehicle traffic model was analysed under the following conditions: urban, rural and on motorways and expressways. The national annual pollutant emission was found to change substantially alongside the changes in vehicle properties over the period analysed; the effect varied due to the performance of respective substances. The relative annual national emission of the various pollutants compared to the situation in 2000 were determined. There was a clear declining trend, from 2008 onwards, in the relative annual emission of pollutants from a representative passenger car; this was valid for all substances.
Environmental assessment of the production process of internal combustion engines
Authors: MROZIK Małgorzata , DANILECKI Krzysztof
Published: March 2021

The aim of this article is to demonstrate using the LCA methodology the environmental effects of material composition changes on Volkswagen Golf passenger cars over the past 30 years. The simplified LCA model of the engine presented in the work shows the energy consumption and total CO2 emissions based on the mass of materials. It was built to investigate general assumptions about material production and car recycling. The results of the research presented in the paper give an image of the modernity of a passenger car engine on the basis of consumption and the degree of recovery of materials used for its construction.
Combustion characteristics of various fuels during research octane number testing on an instrumented CFR F1/F2 engine
Authors: KOLODZIEJ Christopher P. , WALLNER Thomas
Published: March 2021

The Cooperative Fuels Research (CFR) engine is the long-established standard for characterization of fuel knock resistance in spark-ignition internal combustion engines. Despite its measurements of RON and MON being widely used, there is little understanding of what governs the CFR octane rating for fuels of various chemical compositions compared to primary reference fuels (iso-octane and n-heptane). Detailed combustion characteristics were measured on a highly instrumented CFR F1/F2 engine during RON testing of fuels with significantly different chemical composition. The results revealed differences in the cylinder pressure and temperature conditions, as well as knocking characteristics.
The issues of designing of construction features of the internal combustion cam engine
Authors: BOROWCZYK Tomasz , SPADŁO Mikołaj
Published: March 2021

On the pages of the article described cam-piston mechanism developed as an alternative to piston crank mechanism. The main feature of this mechanism is that the piston is dwell in the TDC by the 30°CA and thus allows combustion of the fuel in constant volume. Authors presented the process of designing an analytical cam. The starting point for the calculation was the displacement of piston graph and the limits of acceleration and velocity values obtained. The results of strength calculations of the cam with regard to fatigue problems are also presented. Calculations were carried out in order to reduce the weight of the cam. For this purpose, the Finite Element Method was used.
Operational properties of performance engine intake air cleaners
Authors: DZIUBAK Tadeusz
Published: March 2021

The paper presents an analysis of the design of air cleaners in performance vehicles. The paper confirms that their fundamental property is a much lower flow resistance compared to standard air cleaners. The consequences of replacing a standard air filter element with a performance one have been described. The impact of this modification i.e. an increase (decrease) in the engine torque and power output has been shown. A need to perform tests related to the filtration properties of performance air cleaners has been indicated. A methodology of laboratory research has been developed for performance vehicle air cleaners. The results of the research on the filtration efficiency and accuracy characteristics have been presented along with the flow resistance of air filter elements/air cleaners depending on the dust absorbance coefficient km. The accuracy of the filter element has been evaluated following a Pamas particle counter measurement.
The impact of injector placement on the dose preparation conditions in a gasoline direct injection system
Authors: SIDOROWICZ Maciej , PIELECHA Ireneusz
Published: March 2021

Direct fuel injection requires appropriate conditions for proper ignition of the formed mixture. The proper combustion process is shaped by the direct fuel injection, whose parameters vary. Preparation of the dose requires proper injector placement in the combustion chamber. This article focuses on the issue of the injector specific spatial and angular position in order to implement the injection and atomization of the fuel. The injectors pseudo-optimal location has been presented along with several changed positions. The research was conducted as a simulation experiment using AVL FIRE 2017 software. The best position of the injector was selected based on the fuel spraying and injection process indicators. It has been shown that the spatial position has the most impact and the injector placement angle is of secondary importance.
Comparison of the results of mathematical modeling of a GTM 120 miniature turbine jet engine with the research results
Authors: CHACHURSKI Ryszard , TRZECIAK Adrian , JĘDROWIAK Bartosz
Published: March 2021

The paper presents gas-dynamic calculations of a GTM 120 miniature turbine jet engine. The engine performance parameters have been determined and then validated with theory contained in literature as well as the results of research carried out on a laboratory test stand.
Trends in automotive emissions legislation: impact on LD engine development, fuels, lubricants, and test methods – a global view, with a focus on WLTP and RDE regulations – Summary of the 6th International Exhaust Emissions Symposium (IEES)
Authors: BIELACZYC Piotr , WOODBURN Joseph
Published: March 2021

Among the drivers influencing vehicular powertrain development, the field of vehicular exhaust emissions is experiencing wide-ranging and rapid changes. New emissions regulations such as Euro 6d and new test methods (RDE and WLTP) are the main challenges for the automotive industry caused by political, socioeconomic and technical factors. Air quality is very high on the political agenda and pressure remains to limit and reduce greenhouse gas emissions from the road transport sector. In addition to limits becoming increasingly stringent, the list of parameters subject to legal limits are slowly expanding – and, most importantly, these limits must be met under a wide range of conditions. A range of strategies are available to overcome these difficulties, which was explored during the 6th International Exhaust Emissions Symposium (IEES) hosted at BOSMAL in June 2018. This paper reports and summarises the topics of the 6th IEES and attempts a synthesis on the current status of the field of IC engines, hybrid powertrains and electric vehicles and what the coming years may hold for the automotive and fuel industries and other allied fields.
Signal filtering method of the fast-varying diesel exhaust gas temperature
Authors: PUZDROWSKA Patrycja
Published: March 2021

The paper presents the problem of the impact of external distortions originating on laboratory test stands on the results of measurements of fast-varying diesel exhaust gas temperature. It has been stressed how significant the aspect of the test stand adaptation is during an experiment to ensure the smallest possible impact. This paper, however, focuses on the methods of mathematical processing of a signal recorded during experimental research of a real object. The most significant parameter requiring filtering is the fast-varying exhaust gas temperature in the engine exhaust channel. Methods of mathematical processing adequate to this type of distorted signal have been presented, particularly those that can be used in the Matlab environment and consisting in averaging of the obtained curves of temperature changes. The results of the application of these methods have also been presented on actual curves recorded during laboratory tests and their evaluation has been made.
Investigations on wear and friction in the SI engine valvetrain
Authors: WOŹNIAK Marek , BANICA Cristina Florena , DIACONU Mihai , OZUNA Gustavo , JÓŹWIAK Piotr , SICZEK Krzysztof
Published: March 2021

The engine valvetrain system operating under insufficient oil lubrication conditions, caused by an incorrect installation of the gasket between the block and the head, was tested. The aim of the analysis was to determine the wear intensity and resistance to motion in camshaft bearings. A model including a camshaft, bearings, tappet-valve-spring subassemblies and a part of the lubrication system was developed. It was used to determine the bearing loads and the amount of oil supplied. The volumetric wear of the camshaft journals and bearing covers was measured. For the estimated engine run, the wear rate and resistance to motion were compared for the cases of the engine with correct and incorrect lubrication.
Optical investigation of prechamber combustion in an RCEM
Authors: KOTZAGIANNI Maria , KYRTATOS Panagiotis , BOULOUCHOS Konstantinos
Published: March 2021

In this study, detailed investigations of scavenged prechamber engine combustion are performed experimentally in a Rapid Com-pression Expansion Machine (RCEM), which allows optical access into the main chamber. OH* chemiluminescence measurements combined with pressure measurements are used to study the effect of varying ignition timing on combustion and cycle-to-cycle varia-tions. The variation of ignition timing (pressure at ignition) showed an optimum ignition point for a given injection duration. Earlier ignition resulted in weaker but more reactive jets, coupled to increased cyclic variations. Later ignition did not significantly affect heat release rate, but increased cyclic variation.
Numerical study of fuel and turbulence distributions in an automotive-sized scavenged pre-chamber
Authors: BOLLA Michele , SHAPIRO Evgeniy , KOTZAGIANNI Maria , KYRTATOS Panagiotis , TINEY Nick , BOULOUCHOS Konstantinos
Published: March 2021

This article presents a numerical study of the fuel and turbulence distributions in a pre-chamber at spark-time. The study has been conducted in the framework of the H2020 Gas-On project, dealing with the development of a lean-burn concept for an automotive-sized gas engine equipped with a scavenged pre-chamber. The test case considered studies a 7-hole pre-chamber with circumferentially-tilted orifices mounted on the cylinder head of a rapid compression-expansion machine (RCEM), consistent with the experimental test rig installed at ETH Zurich. An accurate description of turbulence and fuel distributions are key quantities determining the early flame development within the pre-chamber. Both quantities have an influence on the overall combustion characteristics and therefore on the engine performance. For this purpose, computational fluid dynamics (CFD) is employed to complement experimental investigations in terms of data completeness. The performance of the Reynolds-averaged Navier-Stokes (RANS)-based turbulence model is compared with large-eddy simulation (LES) through ensemble averaging of multiple LES realizations, in which the fuel injection rate evolution into the pre-chamber has been perturbed. Overall, RANS results show that the distributions of the turbulent kinetic energy and fuel concentration at spark-time agree well with the LES ensemble-averaged counterparts. This constitutes a prerequisite in view of the combustion phase and the accuracy reported provides further confidence in this regard.
Analysis of influence of using catalyst and polar additives on engine performance and exhaust emission
Authors: TKACZYK Marcin , SKRĘTOWICZ Maria , KRAKOWIAN Konrad
Published: March 2021

In the paper researches of influence of using catalyst and polar additives on engine performance and emission of exhaust were carried out. The tests were made on diesel engine DuraTorq-TDDi/TDCi 16v with a capacity of 1998cm3 produced by Ford company. Two additives were investigated: FMAX – catalytic additive to fuel and HDOS – polar additive to lubricating oil in different proportions. The results indicated that using tested additives has a positive effect on exhaust composition (lower concentrations of nitrogen oxides, soot and carbon monoxide) and also decreased fuel consumption.
Static internal combustion engine operating states in vehicle driving tests
Authors: ANDRYCH-ZALEWSKA Monika , CHŁOPEK Zdzisław , MERKISZ Jerzy , PIELECHA Jacek
Published: March 2021

The article presents the compression-ignition engine test results of static operating states in driving tests: NEDC (New European Driving Cycle), RDE (Real Driving Emissions) and the Malta custom test cycle, developed at the Poznan University of Technology. The NEDC and Malta tests were carried out as drive cycle simulations on the engine test bench, the RDE test was carried out in the real driving conditions. The engine operating states are described by the physical quantities of speed and torque. For each of the tests, zero- -dimensional characteristics of the values describing the engine operation states were determined, including: mean value and average standard deviation and coefficient of variation. Histograms of quantities describing the engines operating states for considered tests and driving conditions were also determined. A large diversity of zero-dimensional characteristics of the quantities describing the engines operating states for the considered driving tests and driving conditions was found.
Representativeness of emissions of toxic substances in bench tests reflecting the road traffic conditions of a vehicle
Authors: WIŚNIOWSKI Piotr , GIS Maciej
Published: March 2021

The results of measurements of exhaust emissions in real road traffic differ significantly from the results of stationary homologation tests. One of the solutions, helpful in determining the actual emission, is the creation of stationary exhaust emission tests simulating the use of the vehicle on the road. The article presents the method of reconstructing the synthetic driving test obtained on the basis of road tests and presents the obtained profile of the speed course. The authors discussed the reasonableness of selecting the emission component determining the correctness of the representativity of the stationary test obtained, which determines the amount of work done by the engine.
Effects of water injection to the fuel and air mixture on equilibrium gas composition in combustion products and selected parameters of the theoretical Otto cycle
Authors: SUCHETA Andrzej
Published: March 2021

Moisturizing the intake air by spraying water in the liquid phase significantly lowers the intake air temperature, mainly due to the high value of latent heat of evaporation. The paper presents a methodology for calculating the parameters of the air-fuel mixture after water injection and during subsequent processes of the Otto cycle: compression, combustion and expansion of exhaust gases. For octane as a fuel, exemplary calculations have been carried out to investigate the effect of water injection on the composition of combustion products and selected parameters of the theoretical Otto cycle (temperature, pressure, output power and thermal efficiency).
Effect of aging and interaction of cooling fluid with heat exchangers material in long-lasting durability test
Authors: FABER Joanna , JURASZ Zbigniew , BRODZIK Krzysztof
Published: March 2021

Efforts to improve engine cooling efficiency by usage of heat exchanger as well as research on cooling fluids composition and properties are well described. Studies on heat exchangers are focused mainly on their durability properties, while cooling fluids development is lately concentrating on nanofluids. In this paper physicochemical properties changes of diluted glycol-based cooling fluid in a long-term durability test of vehicle heat exchanger, were investigated. Following parameters were measured: density of coolant, pH value, elements content in coolant, and reserve alkalinity. Above mentioned analyses were performed on samples collected both in the beginning and periodically after every 500 hours of durability test which lasted for 3000 hours in total. The performed study leads to conclusion that interaction of cooling fluid with material of heat exchanger and changes in glycol composition during long-lasting durability test allows to determine aging effect of applied glycol solution on heat exchanger wear.