Disinfection Methods

Water must be made safe to drink, and an important step in ensuring water safety is disinfection. Disinfectants are added to water to kill disease-causing microorganisms. Ground water sources can be disinfected by “The Water Treatment Rule,” which requires public water systems for disinfection. Chlorination, ozone, ultraviolet light, and chloramines are primary methods for disinfection. However, potassium permanganate, photocatalytic disinfection, nanofiltration, and chlorine dioxide can also be used. Organic material is naturally present in water. Certain forms of chlorine can react with these organic materials and result in the formation of harmful by-products; the U.S. Environmental Protection Agency has anticipated maximum levels for these contaminants

Biological Importance of Essential Oils

Essential oils are the volatile compounds having the oily fragrance. Essential oils are obtained from the different plant parts, and they are extracted from the different techniques and the most preferable method of extraction is the hydrodistillation which is cheap and easy to use. Plant parts including the flowers, leaves, stem, bark and roots are used for the isolation of essential oils. Essential oils are used in almost every field of life and because of these characteristics, the market of essential oils is growing rapidly. Essential oils are used in the aromatherapy and act as antioxidant, antimicrobial, antifungal, pain relievers, anxiety, depression. In the field of cosmetics and industries, the essential oils are used rapidly and mostly used in the perfume industries which are growing increasingly. Essential oils are used in the food preservations and many food items. Essential oils are used as the folk herbal medicines and their fragrance is used for the improvement of the mood and as the depression release

Petrophysical and Geochemical Analysis of Chichali Formation for the Source Rock Evaluation: A Case Study of Chanda-01 Well, Upper Indus Basin, Pakistan

A source rock has the ability of generating hydrocarbons after the maturation of the organic component for a specific period of time. The hydrocarbon generation and release from a potential source rock is dependent on the content of the organic matter, which is determined by Total Organic Carbon (TOC) content. In this research, the Chichali Formation of Cretaceous age is considered to be a source rock in the Chanda gas field, Upper Indus Basin on the basis of petrophysical and geochemical results of well Chanda-01. The study includes computation of TOC, mineralogy and parameters like porosity, permeability and fluid saturation which have been carried out from Well log data. Additionally, geochemical results of the well have been incorporated in order to calibrate and authenticate both results. The formation is encountered at a depth of 4543 m in Chanda-01 well and its thickness is about 34 m. The formation has been divided into two parts on the basis of lithology. The upper part is representing sandy shale, whereas the lower part exhibits massive shale unit. The log data of natural gamma ray, resistivity, density and spectral gamma ray, including uranium, thorium and potassium curves have been interpreted in the lower part of the formation, which confirms that the formation is possibly deposited in anoxic conditions with sufficient organic rich content. Moreover, geochemical analysis of the rock cuttings of the well shows good Vitrinite Reflectance and TOC results which complement the results obtained from the petrophysical analysis. Seven rock samples of Chichali Formation have been analyzed for its TOC & VR value which confirms that shale in this area has fair source potential as the average value of both tests against these samples are greater than 1%. Therefore, having fair source rock potential in Chanda gas field, there is a possibility that Chichali Formation could be a potential source in the other fields of Upper and Middle Indus basins and a prospect for the shale gas resource as well

Performance Evaluation of a Direct Absorption Collector for Solar Thermal Energy Conversion

The solar absorption efficiency of water as a base-fluid can be significantly improved by suspending nanoparticles of various materials in it. This experimental work presents the photo thermal performance of water-based nano-fluids of graphene oxide (GO), zinc oxide (ZnO), copper oxide (CuO), and their hybrids under natural solar flux for the first time. Nanofluid samples were prepared by the two-step method and the photothermal performance of these nanofluid samples was conducted under natural solar flux in a particle concentration range from 0.0004 wt % to 0.0012 wt %. The photothermal efficiency of water-based 0.0012 wt % GO nanofluid was 46.6% greater than that of the other nanofluids used. This increased photothermal performance of GO nanofluid was associated with its good stability, high absorptivity, and high thermal conductivity. Thus, pure graphene oxide (GO) based nanofluid is a potential candidate for direct absorption solar collection to be used in different solar thermal energy conversion applications

Cenwits: A sensor-based loosely coupled search and rescue system using witnesses

Abstract — This paper describes the design, implementation and evaluation of a search and rescue system called CenWits. CenWits uses several small, commonly-available RF-based sensors, and a small number of storage and processing devices. It is designed for search and rescue of people in emergency situations in wilderness areas. A key feature of CenWits is that it does not require a continuously connected sensor network for its operation. It is designed for an intermittently connected network that provides only occasional connectivity. It makes a judicious use of the combined storage capability of sensors to filter, organize and store important information, combined battery power of sensors to ensure that the system remains operational for longer time periods, and intermittent network connectivity to propagate information to a processing center. A prototype of CenWits has been implemented using Berkeley Mica2 motes. The paper describes this implementation and reports on the performance measured from it. I

Microcapsules of Shrimp Oil Using Kidney Bean Protein Isolate and κ-Carrageenan as Wall Materials with the Aid of Ultrasonication or High-Pressure Microfluidization: Characteristics and Oxidative Stability

Emulsions containing shrimp oil (SO) at varying amounts were prepared in the presence of red kidney bean protein isolate (KBPI) and κ-carrageenan (KC) at a ratio of 1:0.1 (w/w). The emulsions were subjected to ultrasonication and high-pressure microfluidization to assist the encapsulation process. For each sample, ultrasonication was carried out for 15 min in continuous mode at 80% amplitude, whereas high-pressure microfluidization was operated at 7000 psi for 10 min. Ultrasonicated and microfluidized emulsions were finally spray-dried to prepare KBPI-KC-SO microcapsules. Moderate to high encapsulation efficiency (EE) ranging from 43.99 to 89.25% of SO in KPBI-KC-SO microcapsules was obtained and the microcapsules had good flowability. Particle size, PDI and zeta potential of KBPI-KC-SO microcapsules were 2.58–6.41 µm, 0.32–0.40 and −35.95–−58.77 mV, respectively. Scanning electron microscopic (SEM) images visually demonstrated that the wall material/SO ratio and the emulsification method (ultrasonication vs microfluidization) had an impact on the size, shape and surface of the KBPI-KC-SO microcapsules. Encapsulation of SO in microcapsules was validated empirically using Fourier transform infrared (FTIR) analysis. Encapsulation of SO in KBPI-KC microcapsules imparted superior protection against oxidative deterioration of SO as witnessed by the higher retention of polyunsaturated fatty acids (PUFAs) and astaxanthin when compared to unencapsulated SO during extended storage at room temperature