To analyze the effect of an increase in the quantity or quality of public investment on growth, this paper extends the World Bank’s Long-Term Growth Model (LTGM), by separating the total capital stock into public and private portions, with the former adjusted for its quality. The paper presents the LTGM public capital extension and accompanying freely downloadable Excel-based tool. It also constructs a new infrastructure efficiency index, by combining quality indicators for power, roads, and water as a cardinal measure of the quality of public capital in each country. In the model, public investment generates a larger boost to growth if existing stocks of public capital are low, or if public capital is particularly important in the production function. Through the lens of the model and utilizing newly-collated cross-country data, the paper presents three stylized facts and some related policy implications. First, the measured public capital stock is roughly constant as a share of gross domestic product (GDP) across income groups, which implies that the returns to new public investment, and its effect on growth, are roughly constant across development levels. Second, developing countries are relatively short of private capital, which means that private investment provides the largest boost to growth in low-income countries. Third, low-income countries have the lowest quality of public capital and the lowest efficient public capital stock as a share of GDP. Although this does not affect the returns to public investment, it means that improving the efficiency of public investment has a sizable effect on growth in low-income countries. Quantitatively, a permanent 1 ppt GDP increase in public investment boosts growth by around 0.1–0.2 ppts over the following few years (depending on the parameters), with the effect declining over time.

In the current work, it was investigated to the K X-ray fluorescence efficiency and chemical effect on vacancy transfer probability for some tin compounds. We used Br₂Tin, TinI₂, SeTin, TinF₂, TinSO₄, TinCl₂, TinO and TinS compounds for experimental study. The target samples were irradiated with ²⁴¹Am annular radioactive source at the intensity of 5 Ci which emits gamma rays at wavelength of 0.2028 nm. The characteristic x-rays emitted because of the excitation are collected by a high-resolution HPGe semiconductor detector. It has been determined that the experimental calculations of the tin (Sn) element are compatible with the theoretical calculation. In addition, we have calculated the experimental intensity ratios, fluorescence yields and total vacancy transfer probabilitiesfor other Sn compounds. 

Seawater desalination has been studied with interest due to the scarcity of fresh water for human consumption. Solar distillation is an old method; the productivity, energy consumption of the process and the cost of the desalinated water thus obtained depend on the efficiency achieved in each of the stages of these systems. The limited capacity to absorb solar radiation and transform it into useful heat for evaporation, interaction with the surrounding medium, and heat losses restrict the overall efficiency of the thermal process and productivity. Since the energy comes from solar radiation, the maximum productivity of this process will be constrained by the magnitude of the total solar radiation available in an area of the planet due to its geographic location, time of year and local climatic conditions. The processes of this energy will be thermodynamically limited by the heat transfer coefficients achieved in the equipment, the maximum value that the evaporation heat can reach, as long as the losses to the environment by convection and radiation are minimal. Comparative analyses of several proposed models, reported data of distillers, reported data of solar radiation that reach average values of up to 7.2–7.4 kwh/m² in some regions of the planet are presented and estimates are made for productivity of these equipments that they reach between 6.7 and 6.9 kg/m² day with a theoretical maximum efficiency of about 0.16 of the total solar radiation.

In many cases, the expected efficiency advantages of public-private partnership (PPP) projects as a specific form of infrastructure provision did not materialize ex post. From a Public Choice perspective, one simple explanation for many of the problems surrounded by the governance of PPPs is that the public decision-makers being involved in the process of initiating and implementing PPP projects (namely, politicians and public bureaucrats) in many situations make low- cost decisions in the sense of Kirchgässner (1948–2017). That is, their decisions may have a high impact on the wealth of the jurisdiction in which the PPP is located (most notably, on the welfare of citizen-taxpayers in this jurisdiction) but, at the same time, these decisions often only have a low impact on the private welfare of the individual decision-makers in politics and bureaucracy. The latter, for example, in many settings often have a low economic incentive to monitor/control what the private-sector partners are doing (or not doing) within a PPP arrangement. The purpose of this paper is to draw greater attention to the problems created by low-cost decisions for the governance of PPPs. Moreover, the paper discusses potential remedies arising from the viewpoint of Public Choice and Constitutional Political Economy.

Objectives: This study aims to examine the impact of Sun Tzu’s Art of War Five Virtues Leadership on innovation and the efficiency of the Chinese brand passenger vehicle industry, explore the role of innovation in enhancing industry efficiency, and propose strategies for leveraging the Five Virtues Leadership to improve operational performance and competitiveness in the sector. Methodology: A mixed research method using quantitative research (questionnaire survey) as the main method and qualitative research (in-depth interview) as the auxiliary method. Result: Quantitative and qualitative research results confirm the positive correlation between the Five Virtues Leadership, innovation, and the efficiency of Chinese brand passenger vehicle companies. And through effective data analysis, it explains the importance of the five virtues of leadership in traditional Chinese culture. Further understanding of the effectiveness and competitiveness of China’s passenger car brands, with leadership references. Conclusion: Five Virtues Leadership can foster a favorable environment for innovation, enhance time utilization, optimize resource allocation, and strengthen brand image. By developing and validating a measurement for Five Virtues Leadership, this study enhances the understanding of its role and significance in modern management, paving the way for future research.

Preserving roads involves regularly evaluating government policy through advanced assessments using vehicles with specialized capabilities and high-resolution scanning technology. However, the cost is often not affordable due to a limited budget. Road surface surveys are highly expected to use low-cost tools and methods capable of being carried out comprehensively. This research aims to create a road damage detection application system by identifying and qualifying precisely the type of damage that occurs using a single CNN to detect objects in real time. Especially for the type of pothole, further analysis is to measure the volume or dimensions of the hole with a LiDAR smartphone. The study area is 38 province’s representative area in Indonesia. This research resulted in the iRodd (intelligent-road damage detection) for detection and classification per type of road damage in real-time object detection. Especially for the type of pothole damage, further analysis is carried out to obtain a damage volume calculation model and 3D visualization. The resulting iRodd model contributes in terms of completion (analyzing the parameters needed to be related to the road damage detection process), accuracy (precision), reliability (the level of reliability has high precision and is still within the limits of cost-effective), correct prediction (four-fifths of all positive objects that should be identified), efficient (object detection models strike a good balance between being able to recognize objects with high precision and being able to capture most objects that would otherwise be detected-high sensitivity), meanwhile, in the calculation of pothole volume, where the precision level is established according to the volume error value, comparing the derived data to the reference data with an average error of 5.35% with an RMSE value of 6.47 mm. The advanced iRodd model with LiDAR smartphone devices can present visualization and precision in efficiently calculating the volume of asphalt damage (potholes).