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Problem-based learning (PBL) is learning where students build knowledge based on learning experiences to solve problems. This model generally is known by teachers around the world and successfully attracted many researchers. However, very limited study has been conducted to analyze this learning model using the typology of knowledge by Pollock and Cruz (1999). This paper analyzed the PBL model using Pollock and Cruz instrument. This study discovered that learning knowledge and facilities contributed to the success of the learning process. However, the internalism typology instrument recommends for the teacher to select and choose appropriate knowledge. Particularly in specific student experience and scaffolding in constructivism through identification and screening system. Another instrument is externalism typology, found that the absorbs of knowledge depends on the developmental age and group compositions, primarily, in first-third grade students. This instrument suggested that a teacher must be more active to be facilitator and mediator in the absorption of knowledge through the assimilation and accommodations mechanism.

The performance of reinforced concrete (RC) element may be deficient for a variety of causes. Correct actions should be taken to resume the performance of the deficient element to maintain the strength and serviceability of the structure. A deficient RC column element may be identified in the form of spalling of concrete cover. A patching method could be selected to recover the damaged area and, hopefully, regain the strength of the damaged RC column to its original value. This research aims to investigate the suitability of patch repair material to recover the performance of damaged RC column. The investigation is carried out by comparing the behaviour of patched RC columns with the corresponding normal RC column. The eccentric loading has been set up in this investigation to induce compression failure of the RC columns. The simulated area of damage is patched using unsaturated polyester resin mortar (UPR mortar). The results indicate that the mode of failure is not induced at the patched sections. The presence of patching causes a redistribution of stress at the patched section in such a way, so a higher stress transfer occurs in the undamaged zone and in the longitudinal reinforcements compared to those of the normal column. The capacity of the patched RC columns is only 71–92% of the normal RC column.

The urban network is an important method of spatial optimization, and measuring the development level of the urban network is a prerequisite for spatial optimization. Combining geographic information system (GIS) spatial analysis, social network analysis, and multidimensional scaling models, we explored the evolution of the urban network spatial structure in the Yangtze River Delta from 1990 to 2017 and proposed corresponding optimization measures. The results showed that the urban network spatial structure of the Yangtze River Delta has evolved from a single-center cluster with Shanghai as its core to a multi-center network with Shanghai as its core and Nanjing, Hangzhou, and Hefei as secondary cores. The density of the urban network has gradually expanded, but the strength of the connection between edge cities such as Chizhou, Suqian, and Quzhou and the core cities needs to be further improved. We found that the evolution of the urban network spatial structure has been driven by preferential attachment, path dependence, and differences in economic and industrial development. Finally, we propose optimizing the urban network spatial structure by strengthening the driving ability of the core cities, clarifying urban functions and development directions, and establishing a unified coordination mechanism. This paper enriches and deepens our understanding of the characteristics of the city network in the Yangtze River Delta, and provides a reference for the optimization of the urban network spatial structure.

The purpose of the “Made in China 2025” strategy is to enhance the innovation capabilities of the local manufacturing industry and achieve green and sustainable development. The role of innovation in the development of manufacturing is a hotspot in academic research, though only a few studies have analyzed the interaction between green technology manufacturing efficiency and its external innovation capabilities. This study used the 2011–2017 Chinese A-share listed manufacturing companies as samples to discuss whether regional innovation capabilities can promote the improvement of green technology manufacturing efficiency. The results showed that a significant spatial correlation between regional innovation capability and green technology manufacturing efficiency was prevalent within spatial heterogeneous bounds. In addition, regional innovation capability directly promoted the effective manufacturing of green technology efficiency, which was strongest in the eastern region of the country. Regional innovation capabilities also had a positive effect on human capital and government revenue, thereby further enhancing the green technology efficiency of manufacturing through the intermediary effect. Based on the above conclusions, some policy recommendations are put forward to facilitate the improvement of China’s regional innovation capabilities in terms of green technology efficiency in manufacturing.

Repair of deteriorated reinforced concrete (RC) elements may be necessary to restore their strength and serviceability. In this research, unsaturated polyester resin (UPR)-mortar is used to repair one-way RC slabs. The performance of the patched RC slabs is investigated experimentally by comparing their behaviour under concentrated load with the corresponding normal slab. The obtained load–deflection relationship up to failure and the cracking failure mode are assessed to determine the efficacy of the UPR-mortar in restoring the strength and serviceability of the slabs. In addition, theoretical ultimate loads determined on the basis of the yield line theory are used to assess the effectiveness of UPR-mortar to restore the strength of the damaged RC slab. As long as a proper execution of repair is carried out, the results indicate a satisfactory performance of UPR-mortar to be used for repairing the damaged RC slabs.

Degradation of reinforced concrete could occur in various forms including spalling of concrete cover as a result of reinforcement corrosion. The degradation would shorthen the service life of the reinforced concrete structure. Patch repair method may be employed to recover this type of degradation using a suitable patch repair material. The authors have developed a patch repair material made from unsaturated polyester resin (UPR)-mortar. In this paper, the mechanical properties of this material which includes compressive strength, elastic modulus, flexural strength and bond strength are highlighted. Comparisons are also made with the normal mortar to emphasize the superior properties of UPR-mortar. Based on these properties, the potential application of UPR-mortar for repairing damaged reinforced concrete slab is examined through finite element simulation. It is pointed out that the tensile stress intensity in the UPR-layer is reduced with a consequence of reducing a risk of cracking in the repair zone. In addition, the patching of damaged zone with UPR-mortar could minimize the deflection.

Degradation of reinforced concrete (RC) element could lead to a reduction of its strength and serviceability. The degradation may be identified in the form of spalling of concrete cover. For the case of RC beam, spalling of concrete cover could occur at the web of the shear span due to corrosion of the web reinfocements. The shear strength of the damaged-RC beam possibly will become less conservative compared to the corresponding flexural strength with a risk of brittle failure. Patch repair could be a choice to recover the size and strength of the damaged-RC beam. This research investigates the shear failure of patched RC beam without web reinforcements with a particular interest to compare the shear failure behaviour of patched RC beam and normal RC beam. The patch repair material used in this research was unsaturated polyester resin (UPR) mortar. The results indicate that the initial diagonal cracks leading to shear failure of patched RC beam occur at a lower level of loading. However, the patched RC beam could carry a greater load before the diagonal crack propagates in length and width causing the beam to fail in shear.

Deteriorated concrete cover, e.g., spalling or delamination, especially when it occurs at the web of a reinforced concrete (RC) beam within the shear span, can reduce the shear capacity of the beam. Patching of this deteriorated area may be the best option to recover the shear capacity of the beam affected. For this purpose, unsaturated polyester resin mortar (UPR mortar) has been formulated. This research aims to investigate the efficacy of UPR mortar in limiting the shear cracking and so restoring the shear capacity of the deteriorated RC beam. The investigation is carried out by an experimental and numerical study. Two types of beams with a size of 150 × 250 × 1000 mm were prepared. The first type of beams was assigned as a normal beam. The other was a beam with a cut off in the non-stirrup shear span, which was eventually patched with UPR mortar. Two reinforcement ratios were assigned for each type of beams. The results show that UPR mortar is effective to hamper the propagation of diagonal cracks leading to increase the shear failure load by 15–20% compared to the reference (normal) beam. The increase of shear strength with the use of UPR mortar is consistently confirmed at various reinforcement ratios.