The impact of tree root systems on wastewater pipes

The sewer system is, second to the drinking water system, the most important part of the public health assets of a city. When it is operating properly, the sewage system is carrying wastewater away from homes and buildings into the wastewater treatment plant and protecting the public health. Also, trees play an essential role in making a city attractive, healthy, and sustainable. Trees provide significant benefits by improving air quality, reducing stormwater runoff, and reducing radiated heat from the streets. However, if tree roots enter into a wastewater pipe they can cause blockages in those pipes, especially if the trees are planted in the wrong place. First of all, this paper will show the damage that can be caused by tree roots. Tree roots can block or reduce flow, cause overflows of sewer content, or damage pipes. This paper will provide several chemical and non-chemical root growing control methods for sewer lines. Also, it will specify some recommendations on how to avoid damage to wastewater pipes caused by roots. Finally, it will provide some recommendations regarding the tree species suitable for planting near wastewater pipes and some trees that should be avoided.Kanalizacijski sustav, uz sustav opskrbe pitkom vodom, je najvažniji dio imovine sustava javnog zdravstva nekog grada. Kada je pravilno održavan, kanalizacijski sustav odvodi otpadnu vodu iz kuća i zgrada prema uređaju za pročišćavanje te štiti zdravlje čovjeka. Također, drveće igra važnu ulogu u gradu budući da grad čini atraktivnim, zdravim i održivim. Drveće ima velikih prednosti poput poboljšanja kvalitete zraka, smanjenja oborinskog otjecanja te smanjenja radijacije topline s ulice. Međutim, korijenje drveća, ukoliko prodre u cijev, može prouzročiti začepljenja kanalizacijskih cijevi, pogotovo ako je posađeno na pogrešnom mjestu. Za početak, u radu će se prikazati šteta koju korijenje drveća može prouzročiti. Korijenje može potpuno blokirati ili smanjiti protok, prouzročiti izlijevanje sadržaja kanalizacije ili oštetiti cijevi. Rad će prikazati neke od kemijskih i nekemijskih metoda kontrole/sprječavanja rasta korijenja u kanalizacijske cijevi. Također, dat će se preporuke kako izbjeći štete na cijevima prouzročene korijenjem drveća. Na kraju će se navesti vrste drveća koje se mogu saditi u blizini kanalizacijskih cijevi i one koje treba izbjegavati

Comparison of conventional and conservation soil tillage systems

Upravljanje poljoprivrednim zemljištem sve više postaje prioritet jer brojna istraţivanja pokazuju da neadekvatno postupanje s poljoprivrednim zemljištem moţe ostaviti brojne negativne posljedice na kvalitetu tla, ali i samog proizvoda koji se sadi na tom tlu. Odrţivo postupanje s poljoprivrednim zemljištem preduvjet je kvalitete, ali i dugoročne obrade poljoprivrednog zemljišta. U ovom radu će se usporediti konvencionalni sustav obrade tla s konzervacijskim sustavom obrade tla kako bi se prikazalo da li je ekološki prihvatljivija obrada poljoprivrednog zemljišta ujedno i ekonomski opravdana. Naime, odrţivi razvoj uključuje ekonomsku, socijalnu i ekološku odrţivost te je stoga bitno promotriti sve parametre.Agricultural land management is becoming a priority nowadays, reason for this are numerous surveys which show that inadequate treatment with agricultural land can leave numerous negative consequences on soil quality, but also on the product that is sown on that soil. Sustainable treatment of agricultural land is a precondition for quality, but also for long-term cultivation of agricultural land. In this paper, a conventional soil treatment system will be copared with a conservation soil treatment system in order to show whether the ecologically more acceptable processing of agricultural land is equally economically justified. Namely, sustainable development includes economic, social and environmental sustainability, and it is therefore essential to consider all parameter

Cybernetics - what is it?

Kibernetika kao znanstvena disciplina je novijeg nastanka, dok se sama riječ koristila još davno. Često se koristi u različitim kontekstima i relativno teško ju je jednoznačno smjestiti u neko određeno područje ljudske djelatnosti. To je i istina, zato što se osnovni principi kibernetike mogu objasniti i shvatiti samo korištenjem pojmova iz različitih grana znanosti. Ona proučava opće zakonitosti procesa upravljanja i komunikacija, neovisno o njihovoj prirodi – u živim i neživim sistemima. U radu će se prikazati nastanak pojma (odnosno znanstvene discipline) kibernetika, povijesni razvoj kibernetike, te neka područja gdje se kibernetika koristi. Cilj rada je ukratko predstaviti i objasniti kibernetiku te, barem do određene mjere, generalno olakšati razumijevanje te vrlo zanimljive, i u novije vrijeme, sve popularnije multidisciplinarne znanosti.Cybernetics, as a scientific discipline, was conceived rather recently, while the word itself has been used for a very long time. It is often used in various contexts, and it is relatively difficult to assign a single meaning to it and define a specific area of human activity which it would designate. Another reason for this is the fact that the basic principles of cybernetics can only be explained and understood by using terms from various other branches of science. It studies the general principles of control and communication systems, regardless of their nature – in both living and inanimate systems. This paper will demonstrate the origin of the term (i.e. the scientific discipline) cybernetics, the development of cybernetics through history, and some areas where cybernetics is applied. The goal of this paper is to briefly introduce and explain cybernetics, and, to a certain extent, make this very interesting and lately increasingly popular multidisciplinary science easier to understand in general

Maintenance in shipping

U radu su analizirane prednosti i nedostaci suvremenih strategija održavanja. Boljim razumijevanjem suvremenih strategija održavanja stvara se podloga za analizu stanja održavanja pojedinog dijela brodskog sustava. Također, navedene su mogućnosti poboljšanja odnosno optimiranja pristupa održavanja za određeni brodski sustav. Cilj rada je što više približiti mogućnosti poboljšanja održavanja odnosno pristupa održavanju, kao i stava prema održavanju. Kao osnovni preduvjet za optimiranje održavanja pojedinog sustava postavlja se poznavanje poznatih strategija održavanja, kao i njihovih prednosti i nedostataka. Potom se određuje način na koji će se optimiranje održavanja provesti za pojedini sustav.In this paper advantages and disadvantages of contemporery strategies of maintenance are analized. Better understanding of contemporary strategies of maintenance creates platform for state analysis for the specific part of ship´s system. Options for improvement are listed for the specific part of ship system. The aim oft his paper is to describe options of improvements of maintenance approaches. The knowledge on well known maintenance strategies, and their pro and cons is considered as well as the different attitudes on the basic condition for optimization of maintenance. For each system is determined the way of optimisation of maintenance

Maintenance in shipping

U radu su analizirane prednosti i nedostaci suvremenih strategija održavanja. Boljim razumijevanjem suvremenih strategija održavanja stvara se podloga za analizu stanja održavanja pojedinog dijela brodskog sustava. Također, navedene su mogućnosti poboljšanja odnosno optimiranja pristupa održavanja za određeni brodski sustav. Cilj rada je što više približiti mogućnosti poboljšanja održavanja odnosno pristupa održavanju, kao i stava prema održavanju. Kao osnovni preduvjet za optimiranje održavanja pojedinog sustava postavlja se poznavanje poznatih strategija održavanja, kao i njihovih prednosti i nedostataka. Potom se određuje način na koji će se optimiranje održavanja provesti za pojedini sustav.In this paper advantages and disadvantages of contemporery strategies of maintenance are analized. Better understanding of contemporary strategies of maintenance creates platform for state analysis for the specific part of ship´s system. Options for improvement are listed for the specific part of ship system. The aim oft his paper is to describe options of improvements of maintenance approaches. The knowledge on well known maintenance strategies, and their pro and cons is considered as well as the different attitudes on the basic condition for optimization of maintenance. For each system is determined the way of optimisation of maintenance

Maintenance issues of the vacuum sewer system

A sewer system is an indispensable part of every settlement which contributes to the protection of the environment and people. There are many types of sewer systems. In addition to the standard sewer systems (mixed, separated, etc.), there are the alternative, non-standard systems, and one of them is a vacuum sewer system. In order for a sewer system to function correctly and to perform its tasks successfully, it needs to be maintained properly and regularly. Generally speaking, maintenance is considered to be a series of activities performed in order to achieve that constructed buildings allow an adequate use and functionality for the purpose they were designed for. Considering these systems are relatively new and still rarely used, there is no general practice or rules for use and maintenance of the same, and, most importantly, there is no user experience or people responsible for managing the work and maintenance. The paper will present the general characteristics and parts of vacuum sewer systems. Maintenance recommendations will be given, and maintenance costs specified making reference to the literature available to the authors

MOEGLICHKEITEN DER ANWENDUNG FACHKUNDIGER METHODEN ZUR OPTIMIERUNG DER WARTUNG VON ABWASSERSYSTEMEN

U radu je dan pregled dosadašnjih istraživanja o mogućnostima primjene ekspertnih metoda (umjetne neuronske mreže, genetski algoritmi, ekspertni sustavi, stabla odlučivanja, Markovljevi lanci i algoritam kolonije mrava) za optimizaciju održavanja sustava odvodnje. Pravodobno održavanje sustava odvodnje važno je zbog njegova pravilnog funkcioniranja, manjih troškova popravaka i osiguranja osnovne funkcije sustava odvodnje, te odvođenja otpadne vode iz kućanstava do uređaja za pročišćavanje otpadnih voda i ispuštanja u prijamnik. Navedene su moguće primjene ekspertnih metoda u optimizaciji održavanja sustava odvodnje čiji je cilj smanjiti troškove održavanja.This paper provides an overview of the state-of-the-art research on the possibilities of using expert methods (artificial neural networks, genetic algorithms, expert systems, decision trees, Markov chains, and ant colony algorithm) for optimising maintenance of sewerage systems. Timely maintenance of sewerage systems is significant as it ensures their proper functioning, repair cost reductions, basic operation of the system, drainage of waste water from households to wastewater treatment plants, and discharge to the receiving water body. Possible uses of expert methods for optimising maiIn dieser Arbeit werden bisherige Forschungsergebnisse zu den Möglichkeiten des Einsatzes von fachkundigen Methoden (künstliche neuronale Netze, genetische Algorithmen, Expertensysteme, Entscheidungsbäume, Markov-Ketten und Ameisenkolonie-Algorithmus) zur Optimierung der Wartung von Abwassersystemen vorgestellt. Die rechtzeitige Wartung des Abwassersystems ist wichtig, da es ordnungsgemäß funktioniert, die Reparaturkosten senkt und die Grundfunktionen des Abwassersystems sicherstellt sowie das Abwasser aus Haushalten in die Kläranlage leitet und in den Auffangbehälter ablässt. Es werden mögliche Anwendungen von fachkundigen Methoden zur Optimierung der Wartung von Abwassersystemen mit dem Ziel, die Wartungskosten zu senken, aufgeführt

Water for all : Proceedings of the 7th international scientific and professional conference Water for all

The 7th International Scientific and Professional Conference Water for all is organized to honour the World Water Day by the Josip Juraj Strossmayer University of Osijek, European Hygienic Engineering & Design Group (EHEDG), Danube Parks, Croatian Food Agency, Croatian Water, Faculty of Food Technology Osijek, Faculty of Agriculture in Osijek, Faculty of Civil Engineering Osijek, Josip Juraj Strossmayer University of Osijek Department of Biology, Josip Juraj Strossmayer University of Osijek Department of Chemistry, Nature Park “Kopački rit”, Osijek- Baranja County, Public Health Institute of the Osijek- Baranja County and „Vodovod-Osijek“ -water supply company in Osijek. The topic of World Water Day 2017 was "Wastewater" emphasizing the importance and influence of wastewater treatments on global environment. The international scientific and professional conference Water for all is a gathering of scientists and experts in the field of water management, including chemists, biologists, civil and agriculture engineers, with a goal to remind people about the significance of fresh water and to promote an interdisciplinary approach and sustainability for fresh water resource management. The Conference has been held since 2011. About 300 scientists and engineers submitted 95 abstracts to the 7th International Scientific and Professional Conference Water for all, out of which 33 was presented orally and 62 as posters. 47 full papers were accepted by the Scientific Committee. 38 full papers became the part of the this Proceedings while 9 papers were accepted for publication in Croatian Journal of Food Science and Technology and Electronic Journal of the Faculty of Civil Engineering Osijek - e-GFOS

A contribution to increasing the efficiency of sewerage systems maintenance by applying a maintenance cost estimation model

U svrhu izrade ove doktorske disertacije provedeno je istraživanje o mogućnosti prikupljanja podataka i informacija o karakteristikama kanalizacijskih sustava u Republici Hrvatskoj te o troškovima njihovog održavanja. Podatci su prikupljeni pomoću upitnika poslanim poduzećima koja upravljaju kanalizacijskim sustavima. Kao rezultat prikupljenih podataka i informacija napravljena je baza podataka koja je služila za razvoj modela procjene troškova održavanja kanalizacijskih sustava. Analizom takve baze podataka te pregledom literature omogućeno je identificiranje varijabli koje su značajne u procjeni troškova održavanja te, na kraju, izrada samog modela za procjenu troškova održavanja kanalizacijskog sustava. Također, razvijena je struktura podataka i troškova održavanja kanalizacijskog sustava koja omogućuje lakše praćenje troškova na godišnjoj razini. Takvim pristupom osigurava se međusobna usporedivost troškova o održavanju kanalizacijskih sustava u Republici Hrvatskoj. Utvrđena je mogućnost primjene linearne regresije kod izrade modela procjene troškova održavanja kanalizacijskog sustava. Budući da je definiran model procjene troškova održavanja kanalizacijskog sustava, utvrđene su i varijable koje najviše utječu na te troškove. Definirane su prednosti i ograničenja modela procjene troškova održavanja. Najveća prednost modela procjene troškova održavanja je jednostavnost uporabe te potreban mali broj podataka o kanalizacijskom sustavu koji su dostupni već u fazi projektiranja. Primjenom modela procjene troškova održavanja moguće je planirati proračun za održavanje kanalizacijskih sustava na razini određenog poduzeća u Republici Hrvatskoj za određena razdoblja. Korištenjem ovog modela očekuje se poboljšanje učinkovitosti održavanja kanalizacijskih sustava i uporaba metode troškova životnog ciklusa budući da će se već pri projektiranju moći procijeniti troškovi održavanja kanalizacijskih sustava.For the purpose of preparation of this doctoral dissertation, a survey was conducted on the feasibility of collecting data and information on the properties of sewerage systems in the Republic of Croatia and on the costs of sewerage systems maintenance. The data were collected through questionnaires sent to companies managing sewerage systems. As a result of collected data and information on the properties and costs of sewerage systems’ maintenance, a database was created. The database was used to develop a maintenance cost estimation model for sewerage systems. The analysis of such a database and literature review has enabled the identification of variables that are significant in estimating maintenance costs and developing the maintenance cost estimation model of the sewerage system. Also, data structure and maintenance costs structure of sewerage system have been developed enabling easier monitoring of annual costs. This approach ensures mutual comparability of maintenance costs on sewerage systems in the Republic of Croatia. The possibility of applying linear regression in developing the maintenance cost estimation model of sewerage system has been established. A maintenance cost estimation model of sewerage system has been defined. In addition to this, the variables that most affect the maintenance cost of sewerage system have been identified. Advantages and limitations of the maintenance cost estimation model have been defined. The greatest advantage of the maintenance cost estimation model is the simplicity of use with a small amount of the required sewerage system data, which are already available at the beginning of the design elaboration process. By applying the maintenance cost estimation model, it is possible to plan a budget for the maintenance of sewerage systems at the level of a particular company in the Republic of Croatia and for specific time period. The use of this model is expected to improve the efficiency of sewerage system maintenance and use of the life cycle cost method, since it will be possible to estimate the maintenance costs of sewerage systems already during the design process

A contribution to increasing the efficiency of sewerage systems maintenance by applying a maintenance cost estimation model

U svrhu izrade ove doktorske disertacije provedeno je istraživanje o mogućnosti prikupljanja podataka i informacija o karakteristikama kanalizacijskih sustava u Republici Hrvatskoj te o troškovima njihovog održavanja. Podatci su prikupljeni pomoću upitnika poslanim poduzećima koja upravljaju kanalizacijskim sustavima. Kao rezultat prikupljenih podataka i informacija napravljena je baza podataka koja je služila za razvoj modela procjene troškova održavanja kanalizacijskih sustava. Analizom takve baze podataka te pregledom literature omogućeno je identificiranje varijabli koje su značajne u procjeni troškova održavanja te, na kraju, izrada samog modela za procjenu troškova održavanja kanalizacijskog sustava. Također, razvijena je struktura podataka i troškova održavanja kanalizacijskog sustava koja omogućuje lakše praćenje troškova na godišnjoj razini. Takvim pristupom osigurava se međusobna usporedivost troškova o održavanju kanalizacijskih sustava u Republici Hrvatskoj. Utvrđena je mogućnost primjene linearne regresije kod izrade modela procjene troškova održavanja kanalizacijskog sustava. Budući da je definiran model procjene troškova održavanja kanalizacijskog sustava, utvrđene su i varijable koje najviše utječu na te troškove. Definirane su prednosti i ograničenja modela procjene troškova održavanja. Najveća prednost modela procjene troškova održavanja je jednostavnost uporabe te potreban mali broj podataka o kanalizacijskom sustavu koji su dostupni već u fazi projektiranja. Primjenom modela procjene troškova održavanja moguće je planirati proračun za održavanje kanalizacijskih sustava na razini određenog poduzeća u Republici Hrvatskoj za određena razdoblja. Korištenjem ovog modela očekuje se poboljšanje učinkovitosti održavanja kanalizacijskih sustava i uporaba metode troškova životnog ciklusa budući da će se već pri projektiranju moći procijeniti troškovi održavanja kanalizacijskih sustava.For the purpose of preparation of this doctoral dissertation, a survey was conducted on the feasibility of collecting data and information on the properties of sewerage systems in the Republic of Croatia and on the costs of sewerage systems maintenance. The data were collected through questionnaires sent to companies managing sewerage systems. As a result of collected data and information on the properties and costs of sewerage systems’ maintenance, a database was created. The database was used to develop a maintenance cost estimation model for sewerage systems. The analysis of such a database and literature review has enabled the identification of variables that are significant in estimating maintenance costs and developing the maintenance cost estimation model of the sewerage system. Also, data structure and maintenance costs structure of sewerage system have been developed enabling easier monitoring of annual costs. This approach ensures mutual comparability of maintenance costs on sewerage systems in the Republic of Croatia. The possibility of applying linear regression in developing the maintenance cost estimation model of sewerage system has been established. A maintenance cost estimation model of sewerage system has been defined. In addition to this, the variables that most affect the maintenance cost of sewerage system have been identified. Advantages and limitations of the maintenance cost estimation model have been defined. The greatest advantage of the maintenance cost estimation model is the simplicity of use with a small amount of the required sewerage system data, which are already available at the beginning of the design elaboration process. By applying the maintenance cost estimation model, it is possible to plan a budget for the maintenance of sewerage systems at the level of a particular company in the Republic of Croatia and for specific time period. The use of this model is expected to improve the efficiency of sewerage system maintenance and use of the life cycle cost method, since it will be possible to estimate the maintenance costs of sewerage systems already during the design process