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Increased investment of a photovoltaic (PV) array makes it essential for the client to attain better results from the PV system. The nonlinearity of the PV array and the revolution and rotation of the earth require the appliance of maximum power point tracking (MPPT) to the system. Accordingly, grid connected PV systems have turn out to be renowned, because they do not require battery back-ups to accomplish MPPT. Stand-alone systems could also attain MPPT; however, they require appropriate battery back-ups for this function.

This survey intends to formulate a review on the PV-based microgrid (MG) systems. Here, the literature analyses on diverse techniques associated with PV-based MG systems. It reviews 65 research papers and states the significant analysis. Initially, the analysis depicts various controllers that are contributed in different papers. Subsequently, the analysis also focuses on various features such as PV capacity and inverter topology, and it also analyses the renewable grid source that are exploited in each paper. Furthermore, this paper provides the detailed study regarding the chronological review and performance achievements in each contribution. Finally, it extends the various research issues which can be useful for the researchers to accomplish further research on PV-based MG systems.

This paper has presented a detailed review on PV-based MG systems that were enumerated in the above sections. Here, various controllers along with their better achievements were analyzed and described. From the review, it was known that several PV-based MG systems were really at the point for enabling better power output and conversion efficiency. In conclusion, this paper reviewed about 65 research papers and declared the significant analysis. Initially, the analysis also focused on various controller classifications in PV-based MG systems that were reviewed in this paper. Subsequently, the analysis also focused on various features, such as PV capacity and inverter topology. The analysis also reviewed the performance achievements and renewable gird source that were exploited in PV-based MG systems. At last, this paper has presented various research issues which can be useful for the researchers to accomplish further research on the features of PV-based MG systems.

This paper presents a brief analysis of PV-based MG systems. This is the first work that uses PV-based MG systems for better regulation of MPPT.

This paper aims to shed light on adaptive reuse in traditional architecture (TA) in Erbil, Iraq.

An inductive approach and qualitative method were used in this study. The inductive research approach was used because there was no clear image of adaptive reuse in traditional cafés (TCs) in Erbil. Besides, there are no studies of TCs in Erbil particularly. Thus, there is a lack of knowledge about what adaptations took place in TCs in Erbil. The qualitative method extracted themes and issues from case studies of four TCs in Erbil citadel's buffer zone. This included a physical survey and observation of the TCs in Erbil and 18 semi-structured interviews with the owners, servers and visitors.

The analysis shows the flexibility of the TCs in Erbil as a face of adaptive re-use (AR) which is explained through the capacity linked to space modifications, the addition of modern devices, the function linked to space modifications, service addition, the condition linked to space modifications and the addition of modern devices. Also, TCs in Erbil has a spatial identity and architectural value that proves it is worthy enough to be preserved through unique spirituality linked to preserving the place.

The findings are limited to the cases of TCs in mountain regain and may not be applicable or appropriate to other cafés in other different countries.

There are three aspects of authenticity in the current research. Firstly, the TCs in Erbil have not been studied before. Secondly, TCs that have been discovered have made AR of themselves whilst maintaining their original function-serving beverages, to stimulate creativity. Thirdly, most of the studies of AR have dealt with historical and heritage architecture, whilst the current research paper is dealing with TA.

This paper allows more accurate estimation of the economy in investing in PV electrification for buildings, especially for Gulf Cooperation Council Countries (GCCC) where they have nearly similar climate and building structure. The actual solar electricity yield from this building is used to make empirical modelling.

The accurate automated daily-recorded solar electricity from 8.64 kW solar PV on a rooftop of Sadeem Building at Awali, Bahrain, was modelled to polynomial equations of order of 6. The effect of the tilt (β) and azimuth (Ψ) angle of PV panels for smart and sustainable buildings is studied.

The correlation of each set of polynomial equation (R²) is listed and had reached a highest value of 0.9792 (for order of 6) with lowest value of 0.1853 (for order of 1). The model may be also applied to the GCCC. The results show that each kW of PV will have a solar electricity yield, on average, of 4.1 kWh. It also shows that the tilt angle has little influence on the solar electricity yield (less than 10%) when the tilt angle changed from 26° to 0° or from 26° to 50°. The influence of the azimuth angle is found to be more than 50% in changing Ψ from 90° to 180°.

The model may not be restricted to Bahrain but applies – to a certain extent – to GCCC (six countries) and to other countries having buildings with similar roof design and at latitude close to the latitude of Bahrain.

The model enables developers and investors to estimate, with high accuracy, the solar electricity provided from a building if PV panels are to be installed on its rooftop (or facade) at different tilt (β) and azimuth (Ψ) angle for smart and sustainable buildings.

Empirically finding out how much each kW of solar PV integrated to the building will produce solar energy electricity (in kWh), that is, 1 kW of PV yield, on average, 4.1 kWh.

Establishing empirical models to evaluate the outcome of each installed kW of PV panels. Each 1 kW installation of PV panels is 4.0 kWh/day, on average. This is less than what commercial companies claim for this region, that is, 1 kW produces 5.5 kWh/ day – which affects the estimated economic outcome of PV projects.

The purpose of this paper is to optimize the welding parameters: rotating speed and plunging depth of carbon steel and pure copper joints using friction stir spot welding (FSSW) with the aid of the design of experiments (DOE) method.

Carbon steel and pure copper sheets were welded using the FSSW technique with a cylindrical tool and without a probe. The welding parameters were: rotating speed: 1,120, 1,400 and 1,800 RPM and plunging depth: 0.2 and 0.4 mm. The welding process was carried out both with and without pre-heating. The welded specimens were analyzed using a shear tensile test. A microstructural investigation at the optimum conditions was carried out. The results were analyzed and optimized using the statistical software Minitab and following the DOE method.

Pre-heating the sample and increasing the rotating speed and plunging depth increased the tensile shear force of the joint. The plunging depth has the biggest effect on the joint efficiency compared with the rotating speed. The optimum shear force (4,560 N) was found at 1,800 RPM, 0.4 mm plunge depth and with pre-heating. The welding parameters were modified so that the samples were welded at 1,800 RPM and at plunging depths of 0.45–1 mm in 0.05 mm steps. The optimized shear force was 5,400 N. The fractured samples exhibited two types of failure mode: interfacial and nugget pull-out.

For the first time, pure copper and carbon steel sheets were welded using FSSW and a tool without a probe with ideal joint efficiency (95 percent).

This paper aims to interrogate the accountabilities of the foreign companies which have directly invested in the Iraqi oil and gas industry.

Using both qualitative and quantitative methodologies, the authors first map the stakeholder accountabilities (qualitative) of foreign oil and gas companies and second, the authors seek to demonstrate quantitatively – through structural break tests and publicly available sustainability reports – whether these companies have accounted for their environmental and social impacts both to Iraqi people and to the global community.

The authors find that the Western democratic values embedded in stakeholder theory, in terms of sustainability, do not hold the same meaning in cultural contexts where conceptions and application of Western democratic values are deeply problematic. This paper identifies a crucial problem in the global oil supply chain and problematises the application of traditional theoretical approaches in the context of the Iraqi oil and gas industry.

Implications of this study include the refocus of attention onto the local and global environmental impacts of the Iraqi oil and gas industry by foreign direct investments. Such a refocus highlights the reasons and ways that decision makers should accommodate these less salient stakeholders.

The primary contribution is the critique of the lack of environmental accountability of foreign direct investment companies in the Iraqi oil and gas industry. The authors also make theoretical and methodological contributions via the problematisation of the cultural bias inherent in traditional stakeholder theories, and by introducing a quantitative method to evaluate the accountabilities of companies.

The Gulf Cooperation Council (GCC) countries form a unique socioeconomic environment that makes the conclusions of the prior literature not likely to be applicable. GCC countries have huge oil reserves, yet they are aiming at reducing oil dependency through enhancing transparency, increasing foreign direct investments and reforming their governance structure. Their firms are mainly family owned and have low female representation in leadership positions. The study seeks to fill a literature gap by providing a business case supporting the call for gender diverse boards for better governance.

The study examines a sample of GCC-listed firms for the years 2009–2018. Three measures are used to proxy for firm social engagement, namely, CSR strategy score, environmental, social and governance (ESG) disclosure score and social pillar score. To ensure whether the presence of women on board or the number of women on board is influential on social engagements, the authors use the existence of women on board and the percentage of women on board variables. Data are collected using Thomson Reuters, and generalized least squares (GLS) panel data regression is used to estimate relationships.

The authors find that female representation on GCC corporate boards is increasing, yet in a slow path. The reported results support the role of women on boards in prompting firms' social agenda and enhancing the level of sustainability reporting. The results also show that female board representation supports the implementation of climate change policy, business ethics policy and health and safety policy.

The paper evidence the add value of women participation on GCC corporate boards in enhancing boards' functionality and governance. The empirical findings encourage firms and policymakers in the GCC countries to increase the share of females on corporate boards to improve firms' citizenship and facilitate attracting foreign investors.