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This paper aims to review comprehensively the different voltage-boosting techniques and classifies according to their voltage gain, stress on the semiconductor devices, count of the total components and their prominent features. Hence, the focus is on non-isolated step-up converters. The converters categorized are analyzed according to their category with graphical representation.

Many converters have been reported in recent years in the literature to meet our power requirements from mill watts to megawatts. Fast growth in the generation of renewable energy in the past few years has promoted the selection of suitable converters that directly impact the behaviour of renewable energy systems. Step-up converters are a fast-emerging switching power converter in various power supply units. Researchers are more attracted to the derivation of novel topology with a high voltage gain, low voltage and current stress, high efficiency, low cost, etc.

A comparative study is done on critical metrics such as voltage gain, switch voltage stress and component count. Besides, the converters are also summarized based on their advantages and disadvantages. Furthermore, the areas that need to be explored in this field are identified and presented.

Types of analysis usually performed in dc converter and their needs with the areas need to be focused are not yet completely reviewed in most of the articles. This paper gives an eyesight on these topics. This paper will guide the researchers to derive and suggest a suitable topology for the chosen application. Moreover, it can be used as a handbook for studying the various topologies with their shortfalls, which will provide a way for researchers to focus.

This purpose of this study was to assess the effectiveness of the document delivery service according to user perception, and a usage analysis was done to inform collection building and refining. This is especially important in a high-calibre research community, where the usage, interests and research groups and disciplines are still evolving.

To collect the responses of document delivery service users, an online questionnaire was used with 12 multiple-choice questions and two open-ended questions. The questionnaires were sent only to the users of this service, and the responses were collected anonymously. Two surveys were conducted, in 2010 and 2013, with the same questions. The responses are displayed graphically prepared to compare the results. There were 71 responses in 2010 and 95 in 2013.

In both surveys, the majority of users rated the service, staff behaviour, speed, quality, etc. with a high satisfaction level. Document delivery order statistics are a major decision-making tool, in addition to usage analysis, for developing a better, economical and highly utilized collection in brand new libraries.

This is the first published study of user perception of document delivery in Saudi Arabia.

Digital preservation of theses and dissertations (TDs) is crucial for the archiving (long-term preservation) of intellectual content of undergraduate and postgraduate students in universities. This paper aims to investigate the digitization of TDs in three selected academic libraries in Oyo State, south-west Nigeria.

Descriptive survey research design was used for this study. The instrument for data collection was the questionnaire. The study comprised 78 professionals and paraprofessional librarians in the three selected university libraries in Oyo State.

The study revealed that digital preservation of TDs in university libraries is at the developmental stage. Also, the study revealed that most participants strongly agreed that the main purpose for embarking on the digital preservation of TDs was to influence the web ranking of the institutions. Web archiving was the widely adopted method of digital preservation in university libraries. Poor information and communication technology infrastructure, absence of policy and poor funding were identified as major challenges militating against the effective digital preservation of theses in the libraries. Hence, it was recommended that the management of university libraries should be more committed to providing substantial funds to meet the financial obligation for digital preservation initiatives.

The study provides insight into a case study of digitization of theses and dissertation i academic libraries in three selected universities to serve as a basis for further research.

The purpose of this paper is to investigate the current status of electronic theses and dissertations (ETD) projects in Nigerian university libraries.

A survey research methodology was applied. A total of 125 questionnaires were distributed to librarians in eight government‐funded universities in South Eastern Nigeria.

Only three out of the eight universities surveyed have started ETD projects in their libraries. Other universities have the intention of adopting ETD but very little has been done towards this. The study also revealed that university libraries in Nigeria stand to benefit immensely from ETD projects. Some of these benefits as revealed from the findings include enhancing scholarly communication in Nigeria, promoting the global visibility of Nigerian universities, and enhancing research dissemination. The results of the study also revealed some challenges of ETD in Nigeria. Strategies to mitigate these challenges were also identified from the findings.

The paper establishes that the adoption of ETD in Nigerian university libraries is very low. Nigerian universities must therefore adopt a pragmatic approach to develop an ETD program that will facilitate the dissemination of research documented in theses and dissertations.

The originality of the work lies in the empirical evidence obtained from the eight university libraries surveyed.

Switching power converters for photovoltaic (PV) applications with high gain are rapidly expanding. To obtain better voltage gain, low switch stress, low ripple and cost-effective converters, researchers are developing several topologies.

It was decided to use the particle swarm optimization approach for this system in order to compute the precise PI controller gain parameters under steady state and dynamic changing circumstances. A high-gain q- ZS boost converter is used as an intermittent converter between a PV and brushless direct current (BLDC) motor to attain maximum power point tracking, which also reduces the torque ripples. A MATLAB/Simulink environment has been used to build and test the positive output quadratic boost high gain converters (PQBHGC)-1, PQBHGC-8, PQBHGC-4 and PQBHGC-3 topologies to analyse their effectiveness in PV-driven BLDC motor applications. The simulation results show that the PQBHGC-3 topology is effective in comparison with other HG cell DC–DC converters in terms of efficiency, reduced ripples, etc. which is most suitable for PV-driven BLDC applications.

The simulation results have showed that the PQBHGC-3 gives better performance with minimum voltage ripple of 2V and current ripple of 0.4A which eventually reduces the ripples in the torque in a BLDC motor. Also, the efficiency for the suggested PQBHGC-3 for PV-based BLDC applications is the best with 99%.

This study is the first of its kind comparing the different topologies of PQBHGC-1, PQBHGC-8, PQBHGC-4 and PQBHGC-3 topologies to analyse their effectiveness in PV-driven BLDC motor applications. This study suggests that the PQBHGC-3 topology is most suitable in PV-driven BLDC applications.

Many failures of aircraft structural components in the past were attributed to cracks emanating from joints, which are identified as the most critical locations. In cases using the recently emerging structural health monitoring (SHM) systems, continuous monitoring needs be carried out at many major joint locations. The purpose of this paper is to develop computational techniques for fastener joints, including the possible change in contact conditions and change in boundary values at the pin-hole interface. These techniques are used for the prognostic analysis of pin-loaded lug joints with rigid/elastic pin subjected to fatigue loading by estimating the residual life of the component at any given instance to assist the SHM systems.

Straight attachment lug joints with rigid/elastic push-fit pin and smooth pin-hole interface are modelled in commercial software MSC PATRAN. In each case, the joint is subjected to various types of fatigue load cycles, and for each type of cycles, the critical locations and the stress concentrations are identified from the stress analysis. Later, for each type of fatigue cycle, the number of cycles required for crack initiation is estimated. A small crack is located at these points, and the number of cycles required to reach the critical length when unstable crack growth occurs is also computed. The novelty in the analysis of life estimations is that it takes into account possible changes in contact conditions at the pin-hole interface during load reversals in fatigue loading.

The current work on fastener joints brings out the way the load reversals leading to change in contact conditions (consequently changing boundary conditions) are handled during fatigue loading on a push-fit joint. The novel findings are the effect of the size of the hole/lug width, elasticity of the material and the type of load cycles on the fatigue crack initiation and crack growth life. Given other parameters constant, bigger size hole and stiffer pin lead to lesser life. Under load controlled fatigue cycles, pull load contributes to significant part of fatigue life.

The analysis considers the changing contact conditions at the pin-hole interface during fatigue cycles with positive and negative stress ratios. The results presented in this paper are of value to the life prediction of structural joints for various load cycles (for both pull-pull cases, in which the load ratios are positive, and pull-push cycles, where the load ratios are negative). The prognostic data can be used to effectively monitor the critical locations with joints for SHM applications.

This paper analyzes the impact of economic downturns on the revenue and expense sides of city financing for the period 2003 to 2009 using a convenience sample of the audited end of year financial reports for thirty midsized US cities. The analysis focuses on whether and how quickly and how extensively revenue and spending directions from past years are altered by recessions. A seven year series of Comprehensive Annual Financial Report (CAFR) data serves to explore whether citiesʼ revenues and spending, especially the traditional property tax and core functions such as public safety and infrastructure withstood the brief 2001 and the persistent 2007 recessions? The findings point to consumption (spending) over stability (revenue minus expense) for the recession of 2007, particularly in 2008 and 2009.

The purpose of this paper is to suggest the fuzzy quality function deployment (QFD) method to assess LIFENET customers' spoken and unspoken needs in order to achieve the various objectives like: how to decide optimum portfolio for health services strategically; how to assess competitors' market position in order to reckon the market position of LIFENET; and how to set the revised target in order to satisfy the customers' demand and to fetch profit in order to satisfy managers' mission and vision in a competitive market.

A fuzzy QFD method has been devised to take care of the various LIFENET objectives. Fuzzy logic's use has been recommended to remove the uncertainty, vagueness, and impreciseness from data obtained to assess customers' spoken and unspoken needs. Symmetric triangular fuzzy numbers (STFNs) may be used to assess various needs to enhance data accuracy. House of quality (HOQ), an in‐built QFD matrix, may be constructed to take care of LIFENET's various requirements in order to satisfy internal and external customers.

Fuzzy QFD plays a vital role in assessing customers' need in terms of WHATs. Various WHATs thus obtained can be accomplished by incorporating technical parameter HOWs'. The QFD HOQ offers various vital comparisons for instance, WHATs vs HOWs, HOWs vs HOWs, NOWs vs WHATs, etc. to obtain important inferences, which help to revise target to remain competitive in the market. Fuzzy QFD helps devise a management strategy to follow customers' needs in health industry successfully.

Accessing Indian customers' needs poses many challenges as the decision to opt for a given healthcare service is most uncertain because it varies from person to person. The set of parameters that influence individual decisions to opt for healthcare services are costs, treatment response time, disease/risk, and health service satisfaction. Fuzzy QFD may help LIFENET promoters to consider customers' favored health services thereby helping strategically in their attempt for major expansion, in order to get the most benefits of becoming first‐movers in the sector. Fuzzy QFD may also help LIFENET to avert major investment decisions that looked attractive in short‐term, but in fact were unfruitful, in long‐term.

This paper aims to introduce the quasi impedance source inverter (qZSI)-based static compensator (STATCOM), which is incorporated into the hybrid distributed power generation system for enhancement of power quality. The distributed power generation system includes the photovoltaic (PV), wind energy conversion system (WECS) and battery energy storage system.

The WECS is used by the self-excited induction generator (SEIG) and the flywheel energy storage system (FESS). To regulate its terminal voltage and frequency, the SEIG requires adjustable volt-ampere reactive (VAR). A combination of a STATCOM and a fixed condenser bank usually serves to satisfy the VAR demand. The maximum correntropy criterion-based adaptive filter technique (AFT) is proposed to control the qZSI-STATCOM and to guarantee that the voltage at the SEIG terminal is harmonic-free while providing non-linear three-phase and single-phase loads.

The coordinated operation of the suggested voltage control and flywheel control systems ensures that load voltage and frequency are retained in their respective values at very low harmonic distortions regardless of wind speed and load variation. The simulation and experimental studies are carried out under different load conditions to validate the efficiencies of the PV-assisted STATCOM.

To improve system stability and minimize total costs, extra load current sensors can also be avoided. This paper proposes to control the SEIG terminal voltage and harmonic elimination in the standalone WECS systems using maximum correntropy criterion-based AFT with a fuzzy logic controller.