The development status of flat panel solar water heater and the composition of water heater are described. The solar radiation in three typical weather conditions of sunny, cloudy and rainy days is studied. The hot water temperature, heat and heat collector efficiency are studied. The results show that the influence of the weather on the solar irradiance is large, and the irradiance has a great influence on the water temperature.

A Detailed geophysical investigation was conducted on Knossos territory of Crete Island. Main scope was the detection of underground archaeological settlements. Geophysical prospecting applied by an experienced geophysical team. According to area dimensions in relation to geological and structural conditions, the team designed specific geophysical techniques, by adopted non-catastrophic methods. Three different types of geophysical techniques performed gradually. Geophysical investigation consisted of the application of geoelectric mapping and geomagnetic prospecting. Electric mapping focusses on recording soil resistance distribution. Geomagnetic survey was performed by using two different types of magnetometers. Firstly, recorded distribution of geomagnetic intensity and secondly alteration of vertical gradient. Measured stations laid along the south-north axis with intervals equal to one meter. Both magnetometers were adjusted on a quiet magnetic station. Values were stored in files readable by geophysical interpretation software in XYZ format. Oasis Montaj was adopted for interpretation of measured physical properties distribution. Interpretation results were illustrated as color scale maps. Further processing applied on magnetic measurements. Results are confirmed by overlaying results from three different techniques. Geoelectric mapping contributed to detection of a few archaeological targets. Most of them were recorded by geomagnetic technique. Total intensity aimed to report the existence of magnetized bodies. Vertical gradient detected subsurface targets with clearly geometrical characteristics.

The structure, thermodynamic stability, ionization potential (IP) and electron affinity (EA) energy level difference (E_g) and tension of lowest unoccupied orbit (LUMO) and highest occupied orbit (HOMO) of armchair single wall carbon nanotubes (C-NTs), BN hybrid carbon nanotubes (BC₂N-NTs) and all BN nanotubes (BN-NTs) were systematically studied with AM1 method in this paper. Calculation results show that when n value is constant, (n, n) C-NTs (n = 3,4,5,6) has the largest diameter and BN-NTs has the smallest diameter; (n, n) the values of E_g (HOMO-LUMO) and n of C-NTs and BC₂N-NTs are related; POAV analysis shows that different hybrid atoms have different contributions to the hybrid mode of nanotube atoms and the tension of nanotubes.

The interest in smart grids and new technologies is growing around the world. Countries are investing in the development of new technologies that will help achieve environmental goals, energy supply efficiency, improve energy efficiency and increase consumer involvement in the energy generation. One of such technology is a blockchain. It is believed that the blockchain, combined with a smart grid, provides an opportunity to integrate the activities of all stakeholders, including: generators, distributors and consumers of electricity. The aim of the article is to identify the key research areas discussed by the researchers of both the smart grid and the blockchain issues. An analysis of the Scopus database from 2015 to 2023 was conducted. Using a created bibliometric query, a systematic literature review was conducted. 476 scientific publications relating to the issues addressed were identified. Using the VOSviewer software, a bibliometric analysis was performed using the author’s keywords. The bibliometric maps obtained allowed for the identification of key research areas. The article also presents potential future directions of scientific considerations, which should be focused on the issue of green smart grid and green blockchain. The results presented in the article can inspire researchers looking for research gaps or describing the current state of knowledge in the field of the smart grid and the blockchain issues.

The developmental dilemma of infant and toddler care is examined from a family perspective, and in-depth analyses of infant and toddler care are conducted using Family Systems Theory and Cultural Capital Theory,which are essential to the holistic development of children, the balance between family and work, and the sustainable development of society and the economy.The developmental dilemmas of infant and toddler care are discussed in depth from the family perspective, and solutions are proposed accordingly. By applying family systems theory and cultural capital theory to analyze the root causes and influencing factors of the problem, it provides useful thoughts and suggestions for improving infant and toddler care practices.

The paper lays out basic design options for infrastructure policy. It first sketches mechanisms to assess demand. Then it sets out a hierarchy of issues starting with choice of market structure followed by conduct regulation. Ownership options are largely a function of market structure choices. The implications for finance—the topic of much day-to-day discussion in infrastructure policy-making—follow from these various prior choices. The discussion naturally circumscribes the role for the so-called public-private partnerships, their uses and pitfalls.