Increased population and increasing demands for food in the Indo-Gangetic plain are likely to exert pressure on fresh water due to rise in demand for drinking and irrigation water. The study focuses on Bhojpur district, Bihar located in the central Ganga basin, to assess the groundwater quality for drinking and irrigation purpose and discuss the issues and challenges. Groundwater is mostly utilized in the study area for drinking and irrigation purposes (major crops sown in the area are rice and wheat). There were around 45 groundwater samples collected across the study region in the pre-monsoon season (year 2019). The chemical analytical results show that Ca2+, Mg2+ and HCO3− ions are present in abundance in groundwater and governing the groundwater chemistry. Further analysis shows that 66%, 69% and 84% of the samples exceeded the acceptable limit of arsenic (As), Fe and Mn respectively and other trace metals (Cu, Zn, Pb, Cd) are within the permissible limit of drinking water as prescribed by Bureau of Indian Standard for drinking water. Generally, high as concentration has been found in the aquifer (depth ranges from 20 to 40 m below ground surface) located in proximity of river Ganga. For assessing the irrigation water quality, sodium adsorption ratio (SAR) values, residual sodium carbonate (RSC), Na%, permeability index (PI) and calcium alteration index (CAI) were calculated and found that almost all the samples are found to be in good to excellent category for irrigation purposes. The groundwater facie has been classified into Ca-Mg-HCO3 type.

No abstract

In this paper, I propose a method for estimating the volume of Baltic timber products exported through the Danish Sound, the strait separating the North Sea from the Baltic, during the early modern period. This method is based on the toll levied on the ships passing through the Sound. The main source used in this study is Sound Toll Registers Online. With the expansion of long-distance maritime trade during the early modern period, the Baltic played an important role by supplying naval stores (timber, pitch, tar, etc.) to the Western and Southern European nations. Until now exports of Baltic timber products have been analysed in terms of either the number of pieces or their weight. Both these approaches fail to shed light on the size (width, thickness, length) of timber products. On the other hand, the estimates presented in this article provide a clear picture about the size, hence the volume of the various timber products.

No abstract

An inverter is a device that converts DC battery power to AC electrical power. The converted AC can be used at any required application. The Inverter performs the opposite function of a Rectifier. The aim of this work is to explain about a 12V-DC/220V-AC inverter. This circuit consists of three parts which include the Oscillator, Amplifier and Transformer. The Oscillator is implemented by using the 2N2222 Transistors, amplifier is implemented by MOSFET's IRF630, and finally we require 12V to 220V center tapped step up transformer. The reason for naming the project as Conventional Power Generator is that because of adding some advancement to the circuit such as adding of solar plate to the circuit which will conveniently charge the battery basing on the solar energy available during the day. And remaining portion of the circuit does the job of generating power on the capacity of circuit requirement.