Human Health Risk Assessment of Trace Elements in Tap Water and the Factors Influencing Its Value

(1) Background: The influence of tap water fittings construction and internal pipe-work on the release of heavy metals was investigated. (2) Methods: A statistical approach was applied for the examination of the chemistry of tap water in five different cities in southern Poland. In total, 500 samples were collected (from 100 to 101 samples in each city). The sampling protocol included information on the construction of the water supply network and the physicochemical parameters of measured tap water. (3) Results: The statistical analysis allowed to extract the crucial factors that affect the concentrations of trace elements in tap water. Age of connection, age of tap, age of pipe-work as well as material of connection, material of pipe-work and material of appliance reveal the most significant variability of concentrations observed for As, Al, Cd, Cu, Fe, Mn, Pb, and Zn. Calculated cancer risks (CRs) decrease with the following order of analysed elements Ni > Cd > Cr > As = Pb and can be associated with the factors that affect the appearance of such elements in tap water. The hazard index (HI) was evaluated as negligible in 59.1% of the sampling points and low in 40.1% for adults. For children, a high risk was observed in 0.2%, medium in 9.0%, negligible in 0.4%, and low for the rest of the analysed samples.

Providing Concealed Connections in Kitchens and Confined Areas Having No Provision of Natural Ventilation

The Government of India is promoting usage of PNG in cities and metros in big way which has opened up newer opportunities & challenges for the CGD industry especially catering to Domestic, Commercial & Industrial Consumers meeting the existing regulations & statutory provisions. As per the Provisions of Petroleum and Natural Gas Regulatory Board (Technical Standards and Specifications including Safety Standards for City or Local Natural Gas Distribution Networks) T4S Regulations domestic piping should be in ventilated area. However, currently there is no clear-cut technical guidelines for installation of piping downstream to consumer meter in concealed location and confined spaces. This study suggests guidelines provided in various codes & standards and the practical approaches adopted in various countries for installation of the pipe-work between the Service Regulator (SR) up to and including the steel reinforced rubber hose installed inside the kitchen of the domestic customer, and includes the risers and laterals systems supplying gas to high rise multi occupancy buildings (domestic premises), to facilitate supply of gas to the domestic customers.

STATIC MIXERS IN FLUSHING FLUID CIRCULATION SYSTEMS OF DRILLING RIGS

The work of three static mixer designs in flushing fluid circulation systems of drilling rigs was studied taking into account the basic parameters of drilling mud. Modelling was carried out, and parametric slurry fields were obtained in the pipe work area, that is in a static mixer installation site and in the area of pipeline behind it. The following models were obtained: velocity fields, vorticity fields, turbulence intensity fields, scale turbulence fields along the travel path. Graphs of the parameters changes regarding the tube axis were plotted. The comparative analysis of patterns and curves was carried out. The rational design of static mixer for obtaining of optimum mud mixing technology features is grounded.

Chip Technology Based on High Efficiency DC Power Supply

The switching power supply is the use of modern power electronics, by controlling the switching transistor turn-on and turn-off time ratio, maintaining a stable output voltage of the power supply. Switching power supply technology at the core, it is mainly divided into AC / DC and DC / DC two categories. Switching power supply eliminates bulky frequency transformers, replacing tens of kHz, MHz or even hundreds of kHz frequency transformer. Since the adjustment pipe work in the off state, and thus low power consumption and high efficiency.

Design of Sand-Blasting Lifting Equipment

Due to pipe-laying process changed for Offshore Oil 201 pipelay vessel requires to place sand blasting machine equipment in suite place, to meet the sand-blasting machine to complete the process of laying pipe work cycle which demands for subsea pipelines sandblasting, then the sand-blasting lifting equipment was designed. The equipment consists of a hydraulic lifting platform system, rail trolley system and control system. The experiments showed that the sand-blasting lifting equipment could securely connect with sand-blasting machine, the sand-blasting machine could be lift fast, installation fast in the suite place, meeting the production requirements.