In the context of Vietnam’s extensive international integration, economic concentration emerges as a pivotal strategy employed by businesses across various sectors, notably the retail industry, to foster expansion and bolster competitiveness within the market. As this trend evolves, it necessitates the formulation by the Vietnamese Government of a comprehensive and stringent legal framework tailored to regulate economic concentration among enterprises. Such measures are imperative to preclude the curtailment of market competition, which could potentially undermine the equity and vitality of the business environment in Vietnam. This paper meticulously examines and elucidates theoretical nuances surrounding economic concentration in the retail sector. Additionally, it scrutinizes the current landscape, assessing the impact of extant legislation governing economic concentration and the efficacy of enforcement activities in this realm within the Vietnamese retail sector. Consequently, the paper proffers judicious recommendations to enhance the efficacy of legal mechanisms governing economic concentration to foster competition and fortify Vietnam’s overall economic prowess, particularly within the retail sector.

One of Indonesia’s main characteristics of tourism development is maritime tourism, which is synonymous with archipelagic countries. The diversity of maritime tourism offered by Indonesia will never end, so it needs to be considered more carefully and used relevantly to create sustainable tourism in Indonesia that provides broad benefits for the country. Many maritime tourism locations in Indonesia are beautiful but require more active promotion. The level of security and terrorism issues are a requirement that the government must consider. The novelty of this research describes the potential ecotourism development in the town of Makassar that stakeholders should consider in the formation of tourism policy. The research locations are in Makassar City, Samalona Island, Langkai Island, and Lanjukang Island. Ecotourism developed in the coastal areas of Makassar City, especially in Samalona, Lanjukang, and Langkai Islands, produces superior objects that collaborate elements of nature and society as the main attraction in the long term. Therefore, local governments need to strengthen monitoring of regional geopolitical developments in order to avoid security and terrorism problems that might cause inconvenience to tourists.

Considering the application of the polymer electrolyte membrane fuel cell (PEMFC), the separator thickness plays a significant role in determining the weight, volume, and costs of the PEMFC. In addition, thermal management, i.e., temperature distribution is also important for the PEMFC system to obtain higher performance. However, there were few reports investigating the relation between the temperature profile and the power generation characteristics e.g., the current density distribution of PEMFC operated at higher temperatures (HT-PEMFC). This paper aims to study the impact of separator thickness on the temperature profile and the current density profile of HT-PEMFC. The impact of separator thickness on the gases i.e., H₂, O₂ profile of HT-PEMFC numerically was also studied using CFD software COMSOL Multiphysics in the paper. In the study, the operating temperature and the relative humidity (RH) of the supply gas were varied with the separator thickness of 2.0 mm, 1.5 mm, and 1.0 mm, respectively. The study revealed that the optimum thickness was 2.0 mm to realize higher power generation of HT-PEMFC. The heat capacity of the separator thickness of 2.0 mm was the biggest among the separators investigated in this study, resulting in the dry-up of PEM and catalyst layer was lower compared to the thinner separator thickness. It also clarified the effects of separator thickness of profile gases, e.g., O₂, H₂O, and current density profile became larger under the higher temperature and the lower RH conditions.

The analysis of the accumulation and export of nutrients by the cowpea crop is fundamental for a more sustainable fertilization program, because the definition of the doses of organic fertilizers based only on the estimated maximum yield does not guarantee the maintenance of soil fertility. The objective of this study was to evaluate the effect of fertilization with chicken manure on the productivity, accumulation and exportation of nutrients by the pods of cowpea. A randomized block design was used, with five doses of chicken manure (0; 5; 10; 20 and 40 t ha^-1) and four repetitions. The highest levels of P and Mg were found in the leaves with the application of 40 t ha^-1 of manure. The maximum pod length was 14.47 cm, estimated with the dose of 33.33 t ha^-1 of manure. The highest values of diameter, number of pods per plant and pod productivity were observed at the highest dose of manure applied. In relative terms, that is, total exported in relation to the total extracted by the aerial part, phosphorus is the nutrient most exported by the pods, on average 58%, followed by N (55%), K (43%), Mg (40%), S (38%) and Ca (17%). At the highest dose, although Ca accumulation occurred in large quantities (31.3 kg ha^-1), only 13% of it was exported by the pods. Fertilizing cowpea with chicken manure supplied essential nutrients and increased pod yield from 7.2 (no fertilization) to 16.3 t ha^-1 (fertilization with 40 t ha^-1 of chicken manure). The plant remains of the cowpea constitute an important source of nutrients, being obtained at the highest dose of manure applied (40 t ha^-1) the following amounts of macronutrients (kg ha^-1): N (51.4); P (5.1); K (27.6); Ca (27.1); Mg (8.2); S (5.1), which may return to the soil, with the incorporation of the plants.

In this paper, a detailed mineralogical and genesis investigation have been carried out in the seven locations of the Iron Ore in Hazara area. Thick bedded iron ore have been observed between Kawagarh Formation and Hangu Formation i.e., Cretaceous-Paleocene boundary. At the base of Hangu Formation, variable thickness of these lateritic beds spread throughout the Hazara and Kohat-Potwar plateau. This hematite ore exists in the form of unconformity. X-ray diffraction technique (XRD), X-ray fluorescence spectrometry (XRF), detailed petroghraphic study and scanning electron microscope (SEM) techniques indicated that those iron bears minerals including hematite, chamosite and quartz, albite, clinochlore, illite-montmorillonite, kaolinite, calcite, dolomite, whereas ankerite are the impurities present in these beds. The X-ray fluorescence (XRF) results show that the total Fe₂O₃ ranges from 39 to 56%, with high silica and alumina ratio of less than one. Beneficiation requires for significant increase in ore grade. The petroghraphic study revealed the presence of ooids fragments as nuclei of other ooids with limited clastic supply, which indicate high energy shallow marine depositional setting under warm and humid climate. The overall results show that Langrial Iron Ore is a low-grade iron ore which can be upgraded up to 62% by applying modern mining techniques so as to fulfill steel requirements of the country.