<p> Tuned Liquid Dampers (TLDs) are increasingly being used to suppress the dynamic vibration of tall buildings. An equivalent mechanical model is essential for rapid analysis and design of a TLD. The most common TLD tank geometries are circular, annular and rectangular. Rectangular tanks are utilized for 1-D and 2-D TLDs, whereas circular and annular are usually applied to axisymmetric structures. The amount of fluid that participates in the sloshing motion is directly influenced by the tank geometry. Although not commonly used, a TLD having a curved-bottom tank is expected to perform more effectively due to its relatively large value of effective mass. The main objective of this study is to develop mechanical models for seven TLDs with different tank geometries including the curved-bottom case, and to theoretically investigate the performance of rectangular, vertical-cylindrical and horizontal-cylindrical TLDs.</p> <p> Potential flow theory, linear long wave theory, Lagrange's equations and virtual work method are employed to develop the equivalent mechanical model parameters of TLDs with rectangular, vertical-cylindrical, horizontal-cylindrical, hyperboloid, triangular, sloped-bottom, and parabolic tank geometries. A rectangular, vertical-cylindrical and horizontal-cylindrical TLD are selected for further study using a single-degree-of-freedom (SDOF) model and a two degree of freedom structure-TLD system model applying the derived equivalent mechanical parameters.</p> <p> The dynamic characteristics of the TLDs as a SDOF system are investigated. The mechanical model is verified by comparing calculated values with experimental results for a rectangular TLD. The free surface motion, sloshing force and energy dissipation are found to be dependent upon the excitation amplitude. Analytical results also indicate that the horizontal-cylindrical TLD possesses the greatest normalized sloshing force and energy dissipation among the TLDs considered.</p> <p> The performances of various TLDs installed in a structure are studied in terms of effective damping, efficiency and robustness. Tuning ratio, structural response amplitude, mass ratio and liquid depth are adjusted to investigate their affect on the performance of the studied TLDs. Performance charts are developed and subsequently used to present the results. It is found that small liquid depth ratio and large mass ratio can lead to a robust structure-TLD system with small relative motion ratio between the structure and the vibration absorber. Comparisons of performance between the three TLDs are made and it can be concluded that the horizontal-cylindrical TLD is the most robust and effective device with the smallest relative motion ratio.</p> / Thesis / Master of Applied Science (MASc)

[pt] Esta pesquisa teve como objetivo principal estudar o comportamento das fundações de tanques de grande diâmetro durante o teste hidrostático, por meio da interpretação dos recalques medidos em campo (Caso - Fundação Superficial) e dos recalques perimetrais calculados em uma simulação numérica tridimensional pelo método dos elementos finitos (Caso – Radier Estaqueado), de acordo com as normativas nacionais e internacionais que regulamentam a avaliação dessas estruturas. A metodologia consistiu em interpretar os recalques, tanto medidos, quanto calculados, com base ao descrito na norma N-270 (2020) e complementado com a norma API-653 (2018). Os resultados das análises evidenciaram que, mediante um tratamento adequado dos recalques observados nos dos tanques, é possível não apenas verificar a conformidade dos recalques permitidos pela norma N-270 (2020), mas também compreender o comportamento mecânico dos materiais que constituem os tanques conforme a norma API-653 (2018) analisando, com os critérios de recalque consolidados na norma, os recalques fora do plano. Entre as conclusões deste estudo, destacam-se resultados significativos que ressaltam a necessidade crucial de considerar não apenas os recalques das fundações dos tanques, mas também a avaliação detalhada dos componentes que integram os tanques como parte fundamental da análise. / [en] The main objective of this research was to study the behavior of large-diameter tank foundations during hydrostatic testing, by interpreting the settlements measured in the field (Surface Foundation Case) and the perimeter settlements calculated in a three-dimensional numerical simulation using the finite element method (Piled Radier Case), in accordance with the national and international standards that regulate the evaluation of these structures. The methodology consisted of interpreting the settlements, both measured and calculated, based on what is described in standard N-270 (2020) and complemented with standard API-653 (2018). The results of the analysis showed that, by properly treating the settlements observed at the tank control points, it is possible not only to verify the compliance of the settlements allowed by the N-270 (2020) standard, but also to understand the mechanical behavior of the materials that make up the tanks in accordance with the API-653 (2018) standard by analyzing the out-of-plane settlements using the settlement criteria consolidated in the standard. Among the conclusions of this study are significant results that highlight the crucial need to consider not only the settlements of tank foundations, but also the detailed assessment of the components that make up the tanks as a fundamental part of the analysis.

High-frequency and large amplitude current is a driving requirement for applications such as induction heating, wireless power transfer, power amplifier for magnetic resonant imaging, electronic ballasts, and ozone generators. Voltage-fed resonant inverters are normally employed, however, current-fed (CF) resonant inverters are a competitive alternative when the quality factor of the load is significantly high. The input current of a CF resonant inverter is considerably smaller than the output current, which benefits efficiency. A simple, parallel resonant tank is sufficient to create a high-power sinusoidal signal at the output. Additionally, input current is limited at the no-load condition, providing safe operation of the system. Drawbacks of the CF resonant inverter are associated with the implementation of the equivalent current source. A large input inductor is required to create an equivalent dc current source, to reduce power density and the bandwidth of the system. For safety, a switching stage is implemented using bidirectional voltage-blocking switches, which consist of a series connection of a diode and a transistor. The series diode experiences significant conduction loss because of large on-state voltage. The control of the output current amplitude for constant-frequency inverters requires a pre-regulation stage, typically implemented as a cascaded hard-switched dc/dc buck converter. The pre-regulation also reduces the efficiency. In this dissertation, a variety of CF resonant inverters with two input inductors and two grounded switches are investigated for an inductive-load driver with loaded quality factor larger than ten, constant and high-frequency (~500 kHz) operation, high reactive output power (~14 kVA), high bandwidth (~100 kHz), and high efficiency (over 95 %). The implementation of such system required to question the fundamental operation of the CF resonant inverter. The input inductance is reduced by around an order of magnitude, ensuring sufficient bandwidth, and allowing rich harmonic content in the input current. Of particular importance are fundamental and second harmonic components since they influence synchronization of the zero-crossing of the output voltage and the turn-on of the switches. The synchronization occurs at a particular frequency, termed synchronous frequency, and it allows for zero switching loss in the switches, which greatly boosts efficiency. The synchronous conditions were not know prior this work, and the dependence among circuit parameters, input current harmonics, and synchronous frequency are derived for the first time. The series diode of the bidirectional switch can reduce the efficiency of the system to below 90 %, and has to be removed from the system. The detrimental current-spikes can occur if the inverter is not operated in synchronous condition, such as in transients, or during parametric variations of the load coil. The resistance of the load coil has a wide variance, five times or more, while the inductance changes as well by a few percent. To accommodate for non-synchronous conditions, a low-loss current snubber is proposed as a safety measure to replace lossy diodes. The center-piece of the dissertation is the proposal of a two-phase zero-voltage switching buck pre-regulator, as it enables fixed frequency and synchronous operation of the inverter under wide parametric variations of the load. The synchronous operation is controlled by phase-shifting the switching functions of the pre-regulator and inverter. The pre-regulator reduces the dc current in the input inductors, which is a main contributor to current stress and conduction losses in the inverter switches. Total loss of the inverter switches is minimized since no switching loss is present and minimal conduction losses are allowed. The dc current in the input inductors, once seen as a means to transfer power to load, is now contradictory perceived as parasitic, and the power is transferred to the load using a fundamental frequency harmonic! The input current to the resonant tank, previously designed to be a square-wave, now resembles a sine-wave with very rich harmonic content. Additionally, the efficiency of the pre-regulator at heavy-load condition is improved by ensuring ZVS for with an additional inductive tank. The dissertation includes five chapters. The first chapter is an introduction to current-fed resonant inverters, applications, and state-of-the-art means to ensure constant frequency operation under load's parametric variations. The second chapter is dedicated to the optimization of the CF resonant inverter topology with a dc input voltage, two input inductors, and two MOSFETs. The topology is termed as a boost amplifier. If the amplifier operates away from the synchronous frequency, detrimental current spikes will flow though the switches since the series diodes are eliminated. Current spikes reduce the efficiency up to few percent and can create false functioning of the system. Operation at the synchronous frequency is achieved with large, bulky, input inductors, typically around 1-2 mH or higher, when the synchronous frequency follows the resonant frequency of the tank at 500 kHz. The input inductance cannot be reduced arbitrarily to meet the system bandwidth requirement, since the synchronous frequency is increased based on the inductance value. The relationship between the two (input inductance and the synchronous frequency) was unknown prior this work. The synchronous frequency is determined to be a complicated mathematical function of harmonic currents through the input inductors, and it is found using the harmonic decomposition method. As a safety feature, a current snubber is implemented in series with the resonant tank. Snubber utilizes a series inductance of cable connection between the tank and the switching stage, and it is more efficient than the previously employed series diodes. Topology optimization and detailed design procedure are provided with respect to efficiency and system dynamics. The mathematics is verified by a prototype rated at 14 kVA and 1.25 kW. The input inductance is reduced by around an order of magnitude, with the synchronous frequency increase of 2 %. The efficiency of the power amplifier reached 98.5 % and might be improved further with additional optimization. Silicon carbide MOSFETs are employed for their capability to operate efficiently at high frequency, and high temperature. The third chapter is dedicated to the development of the boost amplifier's large signal model using the Generalized State-space Averaging (GSSA) method. The model accurately predicts amplifier's transient and steady-state operation for any type of input voltage source (dc, dc with sinusoidal ripple, pulse-width modulated), and for either synchronous or non-synchronous operating frequency. It overcomes the limitation of the low-frequency model, which works well only for dc voltage-source input and at synchronous frequency. As the measure of accuracy, the zero-crossing of the resonant voltage is predicted with an error less than 2° over a period of synchronous operation, and for a range of interest for input inductance (25 μH – 1000 μH) and loaded-quality factor (10 – 50). The model is validated both in simulation and hardware for start-up transient and steady-state operation. It is then used in the synthesis of modulated output waveforms, including Hann-function and trapezoidal-function envelopes of the output voltage/current. In the fourth chapter, the GSSA model is employed in development of the PWM compensation method that ensures synchronous operation at constant frequency for the wide variation of the load. The boost amplifier is extended with a cascaded pre-regulator whose main purpose is to control the output resonant voltage. The pre-regulator is implemented as two switching half-bridges with same duty-cycle and phase-shift of 180°. The behavior of the cascaded structure is the same as of the buck converter, so the half-bridges are named buck pre-regulators. ZVS operation is ensured by putting an inductive tank between the half-bridges. Each output of half-bridges is connected to each of input inductors of the boost to provide the PWM excitation. Using the GSSA model, the synchronous condition and control laws are derived for the amplifier. Properties of the current harmonics in the input inductors are well examined. It is discovered that the dc harmonic, once used to transfer power, is unwanted (parasitic) since it increases conduction loss in switches of the boost. A better idea is to use the fundamental harmonic for power transfer, since it does not create loss in the switches. Complete elimination of the dc current is not feasible for constant frequency operation of the amplifier since the dc current depends on the load coil's resistance. However, significant mitigation of around 55 % is easily achievable. The proposed method improves significantly the efficiency of both the buck pre-regulator and the boost. Synchronous operation is demonstrated in hardware for fixed switching frequency of 480 kHz, power level up to 750 W, input voltage change from 300 V to 600 V, load coil's resistance change of three times, and load coil's inductance change of 3.5 %. Measured efficiency is around 95 %, with a great room for improvements. Chapter five summarizes key contributions and concludes the dissertation. / Ph. D.

<p dir="ltr">Waterhemp (<i>Amaranthus tuberculatus</i>)<i> </i>is one of the most problematic weeds in soybean production in the United States. The ability of waterhemp to quickly evolve resistance threatens the utility of many herbicides. The introduction of Xtend^®and Xtendflex^®soybeans allow for the in-season application of dicamba and glufosinate. With an increase in dicamba use in soybeans plus its continued use in corn, there have been many reports of dicamba failure on waterhemp.</p><p dir="ltr">Greenhouse dose response experiments were conducted to screen six populations of waterhemp for resistance to dicamba. Each population was compared to a known sensitive and known resistant population, with 50% growth reduction (GR₅₀) values of 39 g ae ha^-1and 226 g ae ha^-1, respectively. Low-level dicamba resistance was identified in all populations, as they had GR₅₀values that were different from the known sensitive and R:S ratios that varied from 1.7 to 4.4. Additionally, all six populations exhibited at least 50% survival at a 1/2X rate of dicamba where the sensitive only had 30% survival. Therefore, we can conclude that dicamba resistance in waterhemp is present in multiple counties in Indiana.</p><p dir="ltr">In addition to characterizing populations from Indiana, a growth monitoring study was conducted to determine how emergence timing impacted waterhemp growth. In 2021, plants that emerged in the earliest cohort were taller, had more branches, and accumulated more biomass in comparison to later emerging plants at six weeks after flagging. In 2022, drought conditions throughout the month of June impacted growth of earlier emerging plants, and waterhemp that emerged in the latest cohort were taller, had more branches, and accumulated more biomass than earlier emerging cohorts at six weeks after flagging. Seed yields per plant were low in both years, but all cohorts were able to produce seed. This research concludes that in years when soil sufficient moisture is available, earlier emerging waterhemp plants are competitive with crops and later emerging plants can still produce seed.</p><p dir="ltr">Additionally, field trials were conducted to determine herbicide programs in the Enlist^® and Xtendflex^® soybean systems that would best control a waterhemp population with multiple herbicide resistance. At 21 days after the second postemergence application, waterhemp control was highest in two pass systems. The addition of pyroxasulfone to the second postemergence application increased control of waterhemp in the Xtendflex^® system. Waterhemp densities were the lowest and soybean yield was the highest in two pass herbicide programs for both systems. The results indicate that waterhemp resistant to chemistries in HRAC Groups #2, #4, #5, #9, #14, and #27 was most effectively controlled by programs with two herbicides applications, either a preemergence followed by postemergence or two pass postemergence, and included 2,4-D and glufosinate in the postemergence application(s).</p><p dir="ltr">Finally, a waterhemp population from Francesville, IN was characterized for herbicide resistance via a series of field, greenhouse, and laboratory experiments. Preliminary laboratory analysis confirmed resistance to herbicide actives in the HRAC Groups #2 and #14 via target site mutations and to Group #9 via gene amplification. Field research trials indicated inadequate waterhemp control with preemergence applications of pendimethalin and atrazine and postemergence applications of herbicide actives from Groups #2, #9, #14, and #27 as well as glufosinate and dicamba. Greenhouse dose response experiments revealed GR₅₀values for the Francesville population that were significantly higher for dicamba, mesotrione, and topramezone than the known sensitive. R:S ratios of 4.4, 3.3, and 1.8, were documented for dicamba, mesotrione, and topramezone, respectively. Data from all experiments demonstrated that the Francesville population is resistant to herbicide actives in Groups #2, #4, #5, #9, #14, and #27.</p>

A new method of in situ extraction of alcohols from fermentation broth was investigated. The extraction method exploited the latent advantages of the non-equilibrium phase interaction of the fluid system in the flash tank to effectively recover the alcohol. Carbon dioxide gas ranging from 4.2L/min to 12.6L/min was used to continuously strip 2 and 12% (v/v) ethanol solution in a fermentor with a recycle. Ethanol and water in the stripped gas was recovered by compressing and then flashing into a flash tank that was maintained at 5 to 70bar and 5 to 55oC where two immiscible phases comprising CO2-rich phase (top layer) and H2O-rich phase (bottom layer) were formed. The H2O-rich bottom layer was collected as the Bottoms. The CO2-rich phase was continuously throttled producing a condensate (Tops) as a result of the Joule-Thompson cooling effect. The total ethanol recovered from the extraction scheme was 46.0 to 80% for the fermentor containing 2% (v/v) ethanol and 57 to 89% for the fermentor containing 12% (v/v) ethanol. The concentration of ethanol in the Bottoms ranged from 8.0 to 14.9 %(v/v) for the extraction from the 2 %(v/v) ethanol solution and 40.0 to 53.8 %(v/v) for the 12% (v/v) fermentor ethanol extraction. The Bottoms concentration showed a fourfold increase compared to the feed. The ethanol concentration of the Tops were much higher with the highest at approx. 90% (v/v) ethanol, however the yields were extremely low. Compression work required ranged from 6.4 to 20.1 MJ/kg ethanol recovered from the gas stream in the case of 12% (v/v) ethanol in fermentor. The energy requirement for the 2% (v/v) extraction was 84MJ/kg recovered ethanol. The measured Joule-Thompson cooling effect for the extraction scheme was in the range of 10 to 20% the work of compressing the gas. The lowest measured throttle valve temperature was -47oC at the flash tank conditions of 70bar and 25oC. Optimization of the extraction scheme showed that increasing the temperature of the flash tank reduced the amount of ethanol recovered. Increasing the pressure of the flash tank increased the total ethanol recovered but beyond 45bar it appeared to reduce the yield. The 12.6L/min carbon dioxide flow rate favored the high pressure(70bar) extraction whiles 4.2L/min appeared to favor the low pressure(40bar) extraction. The studies showed that the extraction method could potentially be used to recover ethanol and other fermentation products. / Master of Science

The Thesis with title " Armament production for Whermacht and the Army of Aliance in Protectorate of Bohemia and Moravia (1939 - 1945) is interested in detailed description of armament production within quality and quantity armoured of vehicles and infantry weapons made in war years 1939 - 1945 in Czech munition factories. Foreword part deals with Czech production efore Munich agrément,suitable conditions for militarization and empowerment German Army nor the use in industry either for strategy location. In following chapters the work describes main munition factories (Škoda Plzeň - Skoda Werke, ČKD Praha - BMM, Munition faktory Brno)and due to occupation our country,Czechoslovakia,maximal use of technical and human potenciál in Protectorate.The same it documents sale of spare weapons (cannons and munition) and presents German production,too. In other chapters it directs to confrontal of weapons,thein improvement,following development,army tanks, (mainly tank ŠKODA vz. 35, tank ŠKODA vz. 35,light tank LT vz. 38 and later fighter tank and offensive cannons from útočná ČKD Prague , Marder III, Hetzer, Grille), infantry weapons made in Brnopěchotní (Carabine Mauser K98 and gunmachine MG34, MG42, MG131). It mentios the biggest problem of German armament industry during War,that was critical shortage of raw...

The topic of diploma thesis is to design a cast-in-place tank of sewage plant. The tank has circular shape without ceiling slab and will be completely covered in by soil on sides. The tank is a simple construction with complex relation of foundation. It means the construction will be founded according to second geotechnical category. The tank has to be designed as waterproof construction, which is reached by making white tank system. Calculation was made according to ultimate limit state and limit crack width was assessed according to European standards.

The thesis aims to design a device for utilization of waste heat for heating and hot water in NETME Centre in area of FSI VUT in Brno. First of all there is summary of available sources of waste heat and evaluation of serviceability. Next there is design of a device for utilization of waste heat. Design incluades calculation of heat exchangers and selection of particular heat exchangers. It also incluades design of duct system which anables transportation of heated water from heat exchangers to machine room. In machine room is situated storage tank for accumulation of gained waste heat. This storage tank is conected to heating system and to consumption of hot water which anables utilization of waste heat. Finally there is economic evaluation based on amount of gained waste heat, consumption of heat and costs.

The topic of my diploma thesis is air-water heat pumps. The diploma thesis contains three parts. In the first part I describe the theory of air-water heat pumps. In the second part I consider two variants of heating, hot water heating and pool water heating using air-water heat pumps in the family house, Révova. The third experimental part is focused on observation of operational process and calculation of heat factors of air-water heat pump while in the heating model. The calculated heating factors are then compared to the heating factors from the manufacturer's graph.

Thesis (MScAgric (Agricultural Economics))--University of Stellenbosch, 2011. / ENGLISH ABSTRACT: The rising demand of fish due to population growth coupled by stagnation of fish supply from natural capture has led the world to turn to aquaculture to fill in the gap between fish supply and demand. Aquaculture has emerged as the only sustainable way of supplying the rising population with fish. However the rapid expansion of aquaculture has been met with growing concerns over its environmental effects especially waste produced from aquaculture. The net cage system that is currently being used by small scale trout farmers in the Western Cape is an open water based system where release of waste into the water bodies is inevitable and this put into question the long term sustainability of trout farming using net cages in irrigation dams in the Western Cape. This study sought to compare identified production techniques that can be used by aquaculture farmers to reduce accumulation of organic waste in irrigation dams. The proposed ‘clean’ production techniques include use of net cages fitted with Lift-up system, semi intensive floating tank system (SIFTS) and intergrated aquaculture systems. The study revealed that the intergrated aquaculture system is the most effective way of recovering waste that shows great potential of moving aquaculture towards long term sustainability as it fullfills sustainability dimensions such as ‘zero emission’, nutrient recycling and integrated production. Mechanical methods of recovering waste such as Lift-up system and SIFTS are also effective in recovering particulate waste but however dissolved nutrients are lost into the environment. The study went on further to investigate if economic, environmental and social benefits of recovering waste from irrigation dams outweigh the costs of recovering waste using different production techniques. Models of small scale aquaculture farms using the three identified production techniques were developed and compared with a modelled small scale net cage farm where there was no waste recovery. A comparative financial analysis of the modelled small scale trout farms using alternative production techniques carried out showed that trout production using any of the three alternative ‘clean’ production techniques is financially viable with the SIFTS production technique giving the farmer the highest returns, followed by the intergrated system, then the net cage with a Lift-up system and lastly the net cage system without waste recovery. The second part of the study used the contingent valuation method to estimate the environmental and social benefits of removing waste from dams. Households revealed that they were willing to pay (WTP) R40 on average annually to improve water quality from a state where eutrophication had occurred to a state suitable for irrigation and aquaculture. To improve water quality from a state suitable for irrigation to a state suitable for swimming, households were willing to pay R16.67 annually. If water was to be improved from a state suitable for irrigation to a level suitable for domestic purposes, average willingness to pay (WTP) was R26.17 annually. WTP indicate that besides financial benefits associated with using ‘clean’ production techniques there are environmental and social benefits that will arise to the farm community using water from the irrigation dams. / AFRIKAANSE OPSOMMING: Die stygende vraag na vis as gevolg van bevolkingsgroei, tesame met die stagnering van die aanbod van vis vanaf natuurlike vangste het daartoe aanleiding gegee dat die oë van die wêreld op akwakultuur gerig is om die gaping in die voorsiening van vis te vul. Akwakultuur het ontwikkel as die enigste volhoubare manier om aan die groeiende vraag na vis te voldoen. Die vinnige uitbreiding van akwakultuur het egter toenemende besorgdheid in die nadelige omgewingsimpak, veral ten opsigte van akwakultuurafval, tot gevolg gehad. Die nethokstelsel wat tans deur kleinskaalse forelboere in die Wes-Kaap in oop watergebaseerde sisteme gebruik word en die vrystelling van afval in die wateromgewings wat onafwendbaar is, plaas ’n vraagteken oor die langtermyn volhoubaarheid van die nethokstelsel forelboerdery in besproeiingsdamme in die Wes- Kaap. Die studie het ten doel gehad om geïdentifiseerde produksiestelsels wat deur akwakultuurboere gebruik kan word om die akkummulasie van organiese afval in besproeiingsdamme te verminder, te vergelyk. Die voorgestelde “skoon” produksietegnieke sluit in nethokke wat aan ’n opligstelsel gekoppel word, ‘n semi-intensiewe drywende tenk- stelsel (“SIFTS system” in Engels) en ‘n geïntegreerde akwakultuurstelsel. Met hierdie studie is bevind dat die geïntegreerde stelsel die mees effektiewe manier is om afval te herwin en toon potensiaal om akwakultuur op ’n vohoubare pad te plaas aangesien dit aan die volhoubaarheidsdimensies van geen emissie, voedingstofherwinning en geïntegreerde produksie voldoen. Meganiese metodes van afvalherwinning soos die nethokopligstelsel en die SIFTS-stelsel is effektief in die herwinning van vastestofdeeltjies, maar opgeloste voedingstowwe word steeds in die omgewing vrygestel. Die studie het voorts ten doel gehad om te bepaal of die ekonomiese, omgewings- en sosiale voordele om afval uit besproeiingsdamme te herwin, groter is as die herwinningskoste van die verskillende produksietegnieke. Modelle van kleinskaalse akwakultuurplase wat die drie geïdentifiseerde produksiestelsels gebruik, is ontwikkel en aangewend om te vergelyk met ’n nethokstelsel waar geen afvalherwinning gedoen word nie. ’n Vergelykende finansiële ontleding van die gemodelleerde kleinskaalse forelboerderye met die verskillende produksietegnieke is gedoen en daar is bevind dat enige een van die drie “skoon” stelsels finansieel lewensvatbaar is, met die SIFTS-stelsel wat die hoogste vergoeding aan die boer bied, gevolg deur die geïntegreerde stelsel, dan die nethokke aan ’n opligstelsel en dan die nethokstelsel sonder afvalherwinning. Die tweede deel van die studie het van die voorwaardelike (“contingent”) waardasiemetode gebruik gemaak om die omgewings- en sosiale voordele om afval uit besproeiingsdamme te verwyder, te bepaal. Huishoudings het aangetoon dat hulle bereid sou wees om tot R40 per jaar te betaal om die waterkwaliteit te verbeter vanaf ’n toestand waar eutrifikasie plaasgevind het na ’n toestand waar die water vir besproeiing en akwakultuur geskik sou wees. Om die waterkwaliteit vanaf ’n toestand geskik vir besproeiing te verander na ’n toestand geskik om in te swem, sou huishoudings bereid wees om R16.67 per jaar te betaal. Indien water vanaf ’n toestand geskik vir besproeiing verander sou word na ’n toestand geskik vir huishoudelike gebruik, sou huishoudings gewillig wees om jaarliks R26.17 te betaal. Die “gewilligheid om te betaal” dui aan dat daar bo en behalwe die finansiële voordele om van “skoon” produksietegnieke gebruik te maak, ook omgewings- en sosiale voordele vir die plaasgemeenskap bestaan met die gebruik van die water uit die besproeiingsdamme.