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Energy demand of continents, countries, communities and individuals will continue to increase in the phase of increasing population and improvement in the living standards of people. The attempt to meet this ever increasing demand and at the same time protect the environment has resulted in the fast growth of power generation from renewable sources of energy especially from wind through wind power plants and solar through photovoltaic power plants. This growth has been facilitated by various support schemes such as feed-in-tariff scheme, feed-in-premium and quota scheme. Further growth is expected in the future. This is because of the existing support schemes and the expectation of the emergence of improved technologies for harvesting renewable energy.
This development of power generation from renewable sources of energy although positive lead to some distinctive negative effects on the existing electrical network to which they are connected. These negative effects are known and well documented. The fluctuating nature of wind and solar radiation at any given location over a given period of observation is seen to translate into the power they feed into the power network. This fluctuating infeed requires more active management of the network by system operators so as to ensure continuous reliable power generation and delivery. Sometimes the management process lead to non-utilization of power produced by the renewables sources. Secondly, expansion and reinforcement of some existing networks are needed in other to accommodate renewable power generators. These come at a cost. Many studies and researches have been dedicated to finding solutions to these issues.
This work agrees with the use of storage systems as means of solving these issues but the question that remains unanswered is what the optimal way is. There is also a further push given to the view of installing renewable energy plants together with storage systems as a unit in this work. The main task presented in this work, however, is a concept of sizing renewable energy plant and storage systems as a unit. The resulting renewable energy plant-storage unit has the objective of supporting the electrical network to which it will be connected. Firstly the support should be by reducing the fluctuating effect from renewable production. Secondly by helping improve the load hosting capacity of the electrical network. This will be by supplying the part of the load demand leading to the reduction of the overall power drawn by connected loads from the electrical power network.
Historic data of renewable resource and also the load demand at the point or bus of connection are the drivers of this concept. With the earlier mentioned objectives and random or stochastic nature of data involved, particle swarm optimization method is employed in implementing the concept of sizing to arrive at an optimal solution of required sizes of the renewable energy plant-storage system.
The concept of sizing is based on proposing an ideal load demand that can be supplied by a utility under normal operating condition at all time. It follows that any extra demand should be supplied by the optimally sized renewable energy plant-storage unit. In this work sizing results of three scenarios presented. A single node network with three different types of the load was used in testing the effect of optimally sized renewable energy plant-storage system on an electrical network. The outcome of this test showed that the optimally sized renewable energy storage-system improved the ability of the test electrical network to support additional load hence load hosting capacity of test network was improved. The process required modelling and simulation all of which were carried out using MATLAB Simulink software.
With the introduction of the Internet at the end of the last century the modern society was fundamentally changed. Computer systems became an element of nearly all parts of our daily live. Due to the interconnection of these systems local borders are mostly vanished, so that information is accessible and exchangeable anywhere and at anytime. But this increased connectivity causes that physical fences are no longer an adequate protection for computer systems. Whereas the security of commodity computer systems was improved continuously and similarly with their increased connectivity, deeply embedded systems were then and now mostly protected by physical fences. But the ubiquitous availability of embedded systems in personal and commercial environments makes these systems likewise accessible and moves them strongly into the focus of security investigations.
Deeply embedded systems are usually equipped with tiny scale micro controllers, which are limited in their available resources and do not feature secure mechanisms to isolate system resources. Hence, a single error in a local software component is not limited to the component itself, instead the complete system may be influenced. The lack of resource isolation makes tiny scale systems prone for accidental errors but in particular vulnerable for a broad variety of malicious software. For a safe and secure operation of computer systems it is strongly recommended that software components are isolated in such a manner that they have access only to those resources, which are assigned to them. Even though a substantial number of approaches in the context of embedded system’s safety were investigated during the last fifteen years, security was mostly neglected.
This thesis is focused on security aspects where malicious software wittingly tries to bypass available protection mechanisms. The thesis introduces a security platform for tiny scale systems that enforces an isolation of software components considering security aspects. Due to the limited resources of tiny scale systems the proposed solution is based on a co-design process that takes the static and predefined nature of deeply embedded systems into account and includes hardware, compile-time, and run-time partitions to reduce the number of additional run-time components, to avoid performance drawbacks, and to minimize the memory as well as the components footprint overhead. To prove the applicability of the presented platform it was applied and evaluated with two real applications. In addition, an investigation of technologies of commodity computer systems that are suitable to build secure systems is presented. The thesis analyzes their enforcement based on the features provided by the introduced security platform. The contributions of this thesis include an enforcement of a security isolation of system resources on tiny scale systems and enable the development of a broad variety of secure tiny scale system applications.
The chemical and electronic structure of chalcopyrite absorbers with different bulk band gap energies, Egbulk, [i.e., low-gap Cu(In,Ga)Se2 (CIGSe, Egbulk ~ 1.2 eV) and wide-gap CuInS2 (CIS, Egbulk ~ 1.5 eV)] and of buffer/absorber heterointerfaces based on these materials are studied with soft and hard x-ray spectroscopy techniques. Mechanisms that benefit (limit) the performance of low(wide)-gap chalcopyrite-based solar cells are identified. This knowledge is used to develop surface tailoring treatments to optimize buffer/absorber heterointerfaces based on wide-gap chalcopyrites and improve the performance of their solar cells.
Photoemission spectroscopy (PES) characterization of the two absorbers (i.e., CIGSe and CIS) reveal compositional-depth profiles. The changes detected in CIGSe include: a near surface Ga-depletion, a strongly Cu-poor surface and a strong presence of surface Na that (likely) occupies Cu vacancies. A similar Cu-deficiency is found in CIS. The depth-composition changes result in significant widening of the band gap at the surface, Egsurf, (i.e., CIGSe, Egsurf: 1.70 ± 0.2 eV and CIS, Egsurf: 1.88 ± 0.2 eV) as evident by ultraviolet photoelectron spectroscopy (UPS) and inverse photoemission spectroscopy (IPES) measurements. Differences in the interaction of the CIGSe and CIS surfaces with deposited buffer materials are identified. PES and modified Auger parameter studies reveal strong intermixing at the CdS/CIGSe and ZnS/CIGSe heterointerfaces. S L2,3 x-ray emission spectroscopy (XES) measurements of CIGSe substrates submitted to CdS chemical bath deposition (CBD-CdS) treatments show the formation of In2S3 and defect-rich/nanostructured CdS at the interface, compounds with higher band gap values than the measured Egsurf for CIGSe. S L2,3 XES spectra of CIGSe substrates submitted to CBD-ZnS treatments reveal the formation of (Zn,In)(S,Se)2 chemical analogs at the interface. PES and XES measurement series show that the CdS/CIS heterointerface is more abrupt, with no detected interface chemical species. Direct measurement of the band alignment of these heterointerfaces reveals: an ideal conduction band offset (CBO) configuration for CdS/CIGSe (i.e., CBO: +0.11 ± 0.25 eV), a spike CBO configuration for ZnS/CIGSe (i.e., CBO: +1.06 ± 0.4 eV), and a highly unfavorable cliff CBO configuration for CdS/CIS (i.e., CBO: -0.42 ± 0.25 eV). The performance of solar cell devices based on these heterointerfaces is correlated to their CBO configuration.
Two surface tailoring approaches intended to correct the CBO configuration of the CdS/CIS heterointerface are presented. One method is based on rapid thermal processing (RTP) selenization treatments of CIS absorbers, aiming to exchange Se for S in treated samples. The idea behind this approach is to modify the surface of a wide-gap chalcopyrite so that it forms a more favorable heterointerface with CdS, such as heterointerfaces within low-gap chalcopyrite devices. X-ray fluorescence analysis and PES measurements of RTP-treated CIS samples show a greater treatment effect at the surface of the sample compared to the bulk (i.e., surface [Se]/[S+Se] range: 0.23 ± 0.05 to 0.83 ± 0.05, compared to bulk [Se]/[S+Se] range: 0.01 ± 0.03 to 0.24 ± 0.03). Tuning of the Cu:In:(S+Se) surface composition from a Cu-poor 1:3:5 to a 1:1:2 stoichiometry is observed in RTP-treated CIS samples with lower to higher surface Se contents, respectively. UPS measurements show a shift in valence band maximum toward the Fermi level in samples with higher surface Se content (i.e., -0.88 ± 0.1 to -0.51 ± 0.1 eV), as expected for a reduction in Egsurf due to exchange of Se for S. Ultraviolet-visible spectrophotometry reveals a reduction in the optical band gap of samples with greater Se incorporation (i.e., from 1.47 ± 0.05 to 1.08 ± 0.05 eV), allowing for a working window for optimization purposes.
The second tailoring method involves surface functionalization of CIS absorbers with dipole-charge-inducing self-assembled monolayers (SAM) of benzoic acid derivatives and thiol molecules. The introduction of dipole charges between a heterointerface can tune the relative alignment of the electronic bands composing its electronic structure; thus, use of a suitable dipole-inducing SAM could correct the CBO misalignment in the CdS/CIS heterointerface. UPS measurements of the secondary electron cut-off region of CIS samples treated with a selected set of SAMs show a work function modulation of CIS (i.e., 4.4 ± 0.2 eV - 5.2 ± 0.2 eV). Small gains in solar cell parameters of solar cells based on SAM-modified heterointerfaces are measured.
An overview of the performance of chalcopyrite(kesterite)-based solar cells in relation to the electronic properties of their corresponding buffer/absorber heterointerface suggests that optimization approaches extending beyond the buffer/absorber heterointerface may be needed for further performance gains in wide-gap chalcopyrite-based solar cell devices.
Application of ODT to turbulent combustion problems in incompressible and compressible regimes
(2016)
The one-dimensional turbulence (ODT) model is applied to a reactant - to - product counterflow configuration as well as to a shock tube configuration in non-reactive flow and in deflagration and detonation regimes. The model employed herein solves conservation equations for momentum, energy, and species on a one dimensional (1D) domain corresponding to the line spanning the domain between nozzle orifice centers in the counterflow configuration and corresponding to the tube length in the shock tube configuration. The effects of turbulent mixing are modeled via a stochastic process, while the Kolmogorov and reactive length and time scales are explicitly resolved.
In the counterflow configuration, comparisons between model and DNS results for spatial mean and root-mean-square (RMS) velocity, temperature, and major and minor species profiles are shown. The ODT approach shows qualitatively and quantitatively reasonable agreement with the DNS data. Scatter plots and statistics conditioned on temperature are also compared for heat release rate and all species. ODT is able to capture the range of results depicted by DNS. However, conditional statistics show signs of underignition.
To carry out the shock tube simulations, the ODT methodology is extended to include an efficient compressible implementation and a model for capturing shock-induced turbulence is presented. The necessary algorithmic changes to include compressibility effects are highlighted and the model for capturing shock-turbulence interaction is presented. To validate the compressible solver, results for Sod’s shock tube problem are compared against a finite volume Riemann solver. To validate the model for shock-turbulence interaction, comparisons for a non-reactive and a reactive case are presented. First, results of a shock traveling from light (air) to heavy (SF6) with reshock have been simulated to match mixing width growth data of experiments and turbulent kinetic energy results from LES. Then, for one-step chemistry calibrated to represent an acetylene/air mixture, the interaction of a shock wave with an expanding flame front is simulated, and results with 2D simulation (2D-sim) data for flame brush formation and ensuing deflagration-to-detonation transitions (DDT) are compared. Results for the Sod shock tube comparison show that the shock speed and profile are captured accurately. Results for the nonreactive shock-reshock problem show that interface growth at all simulated Mach numbers is captured accurately and that the turbulent kinetic energy agrees in order of magnitude with LES data. The reactive shock tube results show that the flame brush thickness compares well to 2D-sim data and that the approximate location and timing of the DDT can be captured. The known sensitivity of DDT characteristics to details of individual Wow realizations, seen also in ODT, implies that model agreement can be quantified only by comparing Wow ensembles, which are presently unavailable other than in an ODT run-to-run sensitivity study that is reported herein.
A front-tracking algorithm for large-eddy simulation (LES) is developed to untangle the numerical and physical contributions to entrainment in stratocumulus-topped boundary layers. The front-tracking algorithm is based on the level set method. Instead of resolving the cloud-top inversion, it is represented as a discontinuous interface separating the boundary layer from the free atmosphere. The location of the interface is represented as an isosurface of an evolving marker function the evolution of which is governed by an additional transport equation. The algorithm has been implemented in an existing LES code based on the anelastic approximation of the Navier-Stokes equations.
The original LES algorithm is verified against direct-numerical simulation (DNS) data of an idealized two-dimensional cloud-top mixing layer. For this, the subgrid-scale model of the LES code was replaced by a constant molecular viscosity in order to focus on numerical errors only. A grid convergence study confirmed the anticipated global second-order rate of convergence and the convergence to the DNS solution. The slower convergence of the LES code as compared to the higher-order DNS yielded leading-order errors in the mixing layer growth at the coarsest resolutions, which were finer still than typical LES resolutions.
The front-tracking algorithm is verified by LESs of two different convective atmospheric boundary layers: the smoke cloud, a solely radiatively driven boundary layer, and a stratocumulus-topped boundary layer based on data from the DYCOMS II field study. Specifying zero entrainment, it was shown that entrainment in LES can be controlled effectively by the front-tracking algorithm. The algorithm drastically reduces entrainment errors and reduces dependencies of the solution to numerical parameters such as the choice of flux-limiters and grid resolution.
The Electric power crisis is one of the major problems in Bangladesh, the gap between demand and generation is increasing day by day. Moreover, most of the power plants are gas based which will be phased out in future. An alternate electric supply is an essential part for electrifying the developing countries, in this context an innovative approach of rural electrification including DC microgrid, mini-grid and nanogrid would be technically and economically feasible. The thesis draws also attention on the development of technology which enables community owned power system to emerge in the rural areas based on distributed SHS and demand of that community.
Firstly, the electric status and renewable potential in Bangladesh are studied and considered those data into the software based simulation to analysis the technical feasibility to implement DC microgrid by Homer pro tools. The distributed RES (Renewable Energy sources) considered solar PV and biomass. The booming of a large number of individual SHS (Solar Home System) in Bangladesh, bottom-up energy sharing concept would have studied to configure the optimal design of microgrid system and different configuration including grid connected and DC and AC system studied.
Secondly, The PV module is highly dependent on cell temperature and solar irradiance, the ambient temperature, and solar irradiance mathematical equation have been considered to model and simulate in MATLAB/SIMULINK based environment. Similarly charge controller, battery operation, and performance analysis with respect to the PV model. In the distributed energy sources are mainly SHS including large size and regular also model and simulate in MATLAB/SIMULINK software. For instance, the thesis mainly focuses on an optimal design, planning, sizing of DC hybrid microgrid, the SHS, and biomass-based power system with the goal of maximizing the efficiency and reliability. Homer Pro tool used in the work for design an optimal configuration and sizing for technical feasibility.
Finally, a model of DC microgrid compresses with micro sources like SHS systems, µ-CHP, the household loads model in MATLAB/SIMULINK. Decentralized SHS control strategies (droop control) and operation also design and model in MATLAB/SIMULINK environment, where DC – DC converter needs to couple SHS and DC microgrid.
In contrast to traditional data applications, many real-world scenarios nowadays depend on managing and querying huge volumes of uncertain and incomplete data. This new type of applications emerge, for example, when we integrate data from various sources, analyse social/biological/chemical networks or conduct privacy-preserving data mining.
A very promising concept addressing this new kind of probabilistic data applications has been proposed in the form of probabilistic databases. Here, a tuple only belongs to its table or query answer with a specific likelihood. That probability expresses the uncertainty about the given data or the confidence in the answer. The most challenging task for probabilistic databases is query evaluation. In fact, there are even simple relational queries for which determining the occurrence probability of a single answer tuple is hard for #P.
Lineage formulas constitute the central concept under investigation in this work. In short, the mechanism behind lineage formulas facilitates the representation and evaluation of events of the probability space, which is defined by a probabilistic database. On the basis of lineage formulas, we devise a framework that is designed as a combination of a relational database layer and an additional probabilistic query engine.
In particular, the following three aspects are studied:
(i) an efficient construction of lineage formulas,
(ii) an orthogonal combination of lineage optimization techniques, which are performed within the relational database layer and the probabilistic query engine, and
(iii) effective and compact data structures to represent lineage formulas within a probabilistic query engine.
The developed framework provides a novel lineage construction method that is able to construct nested lineage formulas, to avoid large tuple sets within the relational database layer tuples, and to provide full relational algebra support. In addition, the proposed system completely resolves the conflict between the contradicting query plans optimized for the relational database layer and the probabilistic query engine.
The thesis addresses the design of monolithically integrated radio frequency amplifiers for X-band applications. The focus is on low-voltage low-noise amplifiers and efficient power amplifiers with high output power level. The challenge here is to realize stable amplifiers with remarkable performance metrics at low supply voltages. The general approach for stabilization amplifiers in the above frequency range is the use of a cascode topology which, however, requests higher supply voltages then single transistor operation. By using a special passive frequency-selective feedback, the use of the cascode topology could be avoided, and the amplifiers are stabilized over the entire frequency spectrum. Simultaneously, this feedback is used to neutralize the intrinsic feedback of the transistor at operating frequencies. As a result, a frequency dependent performance degeneration of the transistor can be mitigated.
This work describes the influence of the passive frequency-selective feedback. Its usage as well its limitation are explained using the examples of a realized low noise amplifier and different power amplifiers. Further, the design of radio frequency amplifiers at X-band frequencies that employs silicon-germanium heterojunction bipolar transistors is described. All amplifiers were either incorporated in a 0.25 µm SiGe:C BiCMOS technology or in a 0.35 µm SiGe:C bipolar technology. The main achievements of this work include:
- A 8.7 GHz narrow-band low noise amplifier incorporated in a 0.35 µm SiGe bipolar technology. The noise figure is 2.2 dB and the gain 28 dB at a supply voltage of 3 V. The low noise amplifier was subsequently used for a design of a double-balanced I/Q mixer.
- Two packaged high efficient power amplifiers operating at a center frequency of 12 GHz. They are incorporated in a 0.35 µm SiGe bipolar technology. One amplifier uses a transformer-based output matching network and achieves 30.9 % of power-added efficiency and 23.9 dBm of maximum output power at a supply voltage of 1.8 V. The second amplifier utilizes an LC-balun for impedance matching at the output and a power-added-efficiency of 38 % at 1.8 V is measured. The maximum output power was 23.4 dBm.
- A power amplifier in a 0.35 µm SiGe bipolar technology that uses power combining techniques to achieve 30 dBm (1 W) and 30 % of power-added efficiency at 10 GHz and 2 V supply voltage.
- Two power amplifiers, incorporated in a 0.25 µm SiGe:C BiCMOS technology, demonstrating the capability of a non-advanced SiGe process to be used for radio frequency power applications. Power combining techniques, the use of the passive frequency-selective feedback and layout optimization enables the realization of power amplifiers which exhibit an output power of 30 dBm and a power-added efficiency of 35 % at supply voltages lower as 2.6 V.
This thesis deals with geomorphic processes associated with Small-Scale Opencast Mining (SSOM) in the Gatumba sector of the Western Highlands of Rwanda. In this area tin and tantalum mining was carried out for decades, and it has brought about increase in the wealth and standard of living of the people. Though a lot has been done and achieved in soil erosion research, and despite the enormous wealth coming from mining in Rwanda and Gatumba sector in particular, the negative environmental impacts resulting from mining activities were overlooked by miners and stakeholders and are scarcely addressed in the research yet. This trend was bound to last since there were no valid guidelines for assessing impacts and reclamation of mine sites for the operators in the sector. It was recently, in 2007, that restoration of mining areas has received great attention from the Rwanda Geology and Mine Authority.
The objective of the research was to assess and to increase the understanding of geomorphic impact produced by SSOM. In this regards, the following aspects which indicate the types and spatial distribution of geomorphic processes were measured: (i) investigate the landforms typical of SSOM, (ii) map the watershed morphometry of the study area, (iii) analyse the most relevant properties of soils in term of geomorphology, and (iv) to assess the soil loss potential in the study area.
Primary and secondary data were collected from Government agencies and personal observations. Desk study to review papers and relevant literatures, field observation and experiments, laboratory analyses, mapping and modelling using RUSLE were combined together to develop a practical and integrated methodological approach to effect and realize the objectives. The argument guiding this analytical approach is that physical processes produced by mining cannot be assessed through a single method. The first step mainly concentrated on defining mining sites suitable for assessing geomorphic processes. Within the two studied mines, namely Ruhanga and Gatare, different plots were identified based on the post-mining land uses, to investigate the level of soil and landscape degradation by comparing them with that of control sites located outside of mining influence. Modelling using RUSLE in GIS interface enabled to quantify soil loss potential within the mines and the watershed.
Results indicate that the direct processes associated with opencast mining commonly involve pitting and trenching. Indirect and less conspicuous processes emerge as a long-term consequence of mining. They include depletion of organic matter, compaction or loosening of soil particles in mine sites mostly reflected by low content in organic matter, low rating in soil stable aggregates, and often high soil bulk densities which are variably distributed within the mine sites. This could explain the restriction or lowering, or the rapid infiltration of water into the soil during field experiments, as a consequence probably of the sealing of soil pores or the formation of fissures around mine shafts, from which slides or slumps occur. In average, soil organic matter comprises between 1 and 2.5 % on control sites and ex-mine cultivated sites. organic matter content of soils on reclamation sites was in the same ranges with that of control and ex-mine cultivated sites, but could reach 4,8 % in topsoil of some sample locations. The ex-mine self-recovering sites present much lower organic matter content which doesn’t exceed 2 % in general. The soil aggregation rating of the area is from very low (8%) to low (≤13.5 %). In general, the bulk density ranges between 1.29 to 1.56 g cm-3, and locally can attain 1.76 g cm-3. As a consequence, the total porosity changes locally. Application of correlation and multiple regression models showed a strong influence of soil organic matter on the bulk density. Infiltration tests performed on different experimental sites showed differences of rates in water intake rates as in infiltration curves as well. Infiltration rates are variably distributed over the mines. They range from very slow (3.8 mmhr-1) to rapid (111.18 mm hr-1). Atterberg Limits analyses showed that soils of Gatumba Mining District do not possess extreme properties and they are suitable for engineering purposes. The liquid limit ranges between 51 % and 26 %, whereas the plastic limit is comprised between 22 % and 18 %. The highest plastic index (PI) determined was 29 % and the later soil had a plastic index of 6 %.
The average soil loss in the Gatumba watershed is 27.45 t ha-1 yr-1 with a standard deviation of 0.891. More than 65% of land are prone to high rates of soil loss (exceeding 10 t ha-1 yr-1), and an increasing soil erosion follows increasing slope and land use patterns. The maxima of soil erosion rates are found in Upper Kibilira, Kirombozi and Gisuma catchments respectively. Based on different scenarios applied to quantify soil erosion rates, we found that more the organic matter content from 0. 5%, 2% and >2%) is increased with better support practice (from contour, strip and terrace), more the soil erosion potentials are decreased linearly, in the order of 18.8 to 17.8 t ha-1 yr-1 from 2% to >2 % of organic matter content respectively.
To make SSOM more environmentally sustainable, there is a need of developing integrated practices and cross-cutting approaches that reduce the environmental impact of mining operations, and leave mine sites in an acceptable state for reuse by people or systems. Practices such as isolation of soil and earth material, stabilization of slopes and amendments of sites to be restored should be highly considered in the process of rehabilitation of affected sites.
In this study, the aims were to investigate the die-off levels of pathogens attainable under conventional biotreatments, introduce alternative hygienization options and study their performance at eliminating pathogens from biowaste. In addition, the study investigated feasibility of biotreatment of potato peels waste (PPW) as management option for the peels waste generated in Dar es Salaam city. Pathogens inactivation studies using simulated biowaste (moisture ˃77%w/w) composed of PPW spiked with Escherichia coli and Salmonella senftenbergensis at laboratory-scale resulted into low temperature-time patterns of the aerobic In-vessel composting system and turned the process anaerobic thus demonstrated inefficiency at eliminating the spiked bacteria. Likewise, two-phase anaerobic digestion at continuous stirred tank reactor confirmed incapable at effecting complete inactivation of the bacteria unless substrate residence is prolonged above 72hrs. These distasteful confirmations inevitably advocate the importance of applying either pre- and/or post-biotreatment hygienization processes on biowaste for safer biotreatments. Existing hygienization options including acid/lime conditioning and batch pasteurization were applied, their hygienization efficacy investigated and the latter validated. Acetic acid treatment of biowaste at pH value 4 for 5days or lime treatment at pH value 11-12 for 1day brought complete die-off in E. coli and S. senftenbergensis. Temperature-time combination at 65°C for 30min was sufficient at effecting ˃1log cycle die-off of the spiked enteropathogens with z-Value of 11˚C for S. senftenbergensis hence validates the temperature-time regime of 70˚C for 30min and 70˚C for 60min set by U.S-EPA/625/R-92/013 and Regulations (EC) No. 208/2006 respectively. In addition, alternative hygienization options namely UV radiation and passive solar heating (PSH) were proposed, applied and evaluated. Modes of application and achievable bacteria die-off for all hygienization options are given in Chapter 2 to 6 of this document. Owing to its small investment capital (mostly do yourself construction), independence from fuel supplies and low running costs, the study highly recommend PSH as environmental friendly and economic viable pre- and post- biotreatment hygienization option especially for tropical climates and developing countries with adequate sunshine. In vessel co-composting of PPW with yard-waste at 6:1 ratio gave microbiologically safe and good quality compost. Endowed with higher CO2 removal, mesophilic/thermophilic two-phase anaerobic processing of PPW showed comparable results to biogasification from other biowaste. Biogas productivity from PPW was 2.3lNbiogas/l.day with an average CH4 yield of 0.13-0.35m3/kgoTS input having 58% CH4. The digestion resulted into H2S removal from above LoQ to less than 230ppm with 81% VS removal at substrate OLR of 2.4kgoTS/m3.day input without sign of inhibition. It is estimated that 1.0m3biogas with 5hrs burning potential and equivalent to 3.5kg firewood can be produced from 10.2kg of PPW anaerobic digested. The resulting biogas production would complement household energy need thus conserve forest resources which are subjected to high deforestation rate estimated at 4.1kilotons of wood per day as fuelwood. Digestate resulting from the anaerobic reactors would make valuable fertilizer to urban agriculture thus enhance soil fertility and productivity.