Radiological Assesment of Natural Radioactivity Levels in Selected Ceramic Tile Brands used in Kenya

The assessment of the radiation levels of the natural radionuclides 232Th, 238U and 40K in ceramic tiles used in Kenya has been studied. The radiometric analysis was done using a high-efficiency gamma-ray spectrometer.  A total of thirty-seven (37) samples of ceramic tiles were pulverized, weighed accurately, and packaged in 250ml standard plastic containers, well labelled and stored for 28 days to attain secular equilibrium. Analysis of specific gamma energies from activities of 232Th, 238U and 40K reported activity of 53.73±2.34 Bqkg-1, 43.17±3.40 Bqkg-1, and 525.99±36.10 Bqkg-1 respectively. The variatiations in the radiation activity concetration is attributed to the composition of geological raw material used for tiles manufacturing. The average radium equivalent, absorbed dose, indoor and outdoor annual effective dose, and hazard indices (internal and external) obtained were 159.59 BqKg-1, 75.55nGyh-1, 0.28, 0.19, 0.54 and 0.43 respectively. The results obtained from the study showed that the use of ceramic tiles in Kenya does not pose any significant harmful radiation effects to users

Radiological Assesment of Natural Radioactivity Levels in Selected Ceramic Tile Brands used in Kenya

The assessment of the radiation levels of the natural radionuclides 232Th, 238U and 40K in ceramic tiles used in Kenya has been studied. The radiometric analysis was done using a high-efficiency gamma-ray spectrometer.  A total of thirty-seven (37) samples of ceramic tiles were pulverized, weighed accurately, and packaged in 250ml standard plastic containers, well labelled and stored for 28 days to attain secular equilibrium. Analysis of specific gamma energies from activities of 232Th, 238U and 40K reported activity of 53.73±2.34 Bqkg-1, 43.17±3.40 Bqkg-1, and 525.99±36.10 Bqkg-1 respectively. The variatiations in the radiation activity concetration is attributed to the composition of geological raw material used for tiles manufacturing. The average radium equivalent, absorbed dose, indoor and outdoor annual effective dose, and hazard indices (internal and external) obtained were 159.59 BqKg-1, 75.55nGyh-1, 0.28, 0.19, 0.54 and 0.43 respectively. The results obtained from the study showed that the use of ceramic tiles in Kenya does not pose any significant harmful radiation effects to users

Removal of ecotoxicity of 17α-ethinylestradiol using TAML/peroxide water treatment

17α -ethinylestradiol (EE2), a synthetic oestrogen in oral contraceptives, is one of many pharmaceuticals found in inland waterways worldwide as a result of human consumption and excretion into wastewater treatment systems. At low parts per trillion (ppt), EE2 induces feminisation of male fish, diminishing reproductive success and causing fish population collapse. Intended water quality standards for EE2 set a much needed global precedent. Ozone and activated carbon provide effective wastewater treatments, but their energy intensities and capital/operating costs are formidable barriers to adoption. Here we describe the technical and environmental performance of a fast- developing contender for mitigation of EE2 contamination of wastewater based upon smallmolecule, full-functional peroxidase enzyme replicas called “TAML activators”. From neutral to basic pH, TAML activators with H2O2 efficiently degrade EE2 in pure lab water, municipal effluents and EE2-spiked synthetic urine. TAML/H2O2 treatment curtails estrogenicity in vitro and substantially diminishes fish feminization in vivo. Our results provide a starting point for a future process in which tens of thousands of tonnes of wastewater could be treated per kilogram of catalyst. We suggest TAML/H2O2 is a worthy candidate for exploration as an environmentally compatible, versatile, method for removing EE2 and other pharmaceuticals from municipal wastewaters.Heinz Endowments, the Swiss National Science Foundation, the Steinbrenner Institute for a Steinbrenner Doctoral Fellowship. NMR instrumentation at CMU was partially supported by NSF (CHE-0130903 and CHE-1039870)

Mycotoxin Detection Plays “Cops and Robbers”: Cyclodextrin Chemosensors as Specialized Police?

As in a cops and robbers play we discover new mycotoxins and metabolites everyday and we are forced to develop new molecules quickly as chemo- or biosensors or to modify existing molecules able to recognize these new hazardous compounds. This will result in an enormous cost saving to agro-food industry through the prevention and reduction of product recalls and reduced treatment costs. Here we present a brief review of the rapid methods used to detect mycotoxins, considering usefulness and limits. Then we propose a new fast, efficient and cheap methodology, based on a combination of computer chemistry aided design and fluorescence, that can help to drive synthesis in a more efficient way

Immunochemical Methods for Ochratoxin A Detection: A Review

The safety of food and feed depends to a great deal on quality control. Numerous compounds and organisms may contaminate food and feed commodities and thus pose a health risk for consumers. The compound of interest in this review is ochratoxin A (OTA), a secondary metabolite of the fungi Aspergillus and Penicillium. Due to its adverse health effects, detection and quantification are of utmost importance. Quality control of food and feed requires extraction and analysis, including TLC, HPLC, MS, and immunochemical methods. Each of these methods has its advantages and disadvantages. However, with regard to costs and rapidity, immunochemical methods have gained much interest in the last decade. In this review an introduction to immunochemistry and assay design will be given to elucidate the principles. Further, the application of the various formats to the detection and quantification of ochratoxin will be described, including the use of commercially available kits

New Trends in Impedimetric Biosensors for the Detection of Foodborne Pathogenic Bacteria

The development of a rapid, sensitive, specific method for the foodborne pathogenic bacteria detection is of great importance to ensure food safety and security. In recent years impedimetric biosensors which integrate biological recognition technology and impedance have gained widespread application in the field of bacteria detection. This paper presents an overview on the progress and application of impedimetric biosensors for detection of foodborne pathogenic bacteria, particularly the new trends in the past few years, including the new specific bio-recognition elements such as bacteriophage and lectin, the use of nanomaterials and microfluidics techniques. The applications of these new materials or techniques have provided unprecedented opportunities for the development of high-performance impedance bacteria biosensors. The significant developments of impedimetric biosensors for bacteria detection in the last five years have been reviewed according to the classification of with or without specific bio-recognition element. In addition, some microfluidics systems, which were used in the construction of impedimetric biosensors to improve analytical performance, are introduced in this review

Antibody-Based Sensors: Principles, Problems and Potential for Detection of Pathogens and Associated Toxins

Antibody-based sensors permit the rapid and sensitive analysis of a range of pathogens and associated toxins. A critical assessment of the implementation of such formats is provided, with reference to their principles, problems and potential for ‘on-site’ analysis. Particular emphasis is placed on the detection of foodborne bacterial pathogens, such as Escherichia coli and Listeria monocytogenes, and additional examples relating to the monitoring of fungal pathogens, viruses, mycotoxins, marine toxins and parasites are also provided

Belajar mandiri membuat struktur rumah dua lantai dengan SAP 2000

Buku Belajar Mandiri Membuat Struktur Rumah Dua Lantai dengan SAP 2000 ini menyajikan pembahasan analisis struktur bangunan rumah sederhana. Contoh kasus analisisnya, antara lain dari pembebanan atap, pembebanan plat lantai, menganalisis dimensi foot plate, serta penerapan hitungan tersebut ke dalam gambar CAD. Buku ini membantu pembaca dari langkah awal hingga akhir dari proses analisis. Selain itu, buku ini juga mudah dipahami sehingga pembaca diharapkan mempunyai gambaran dan dapat mengaplikasi SAP 2000 dalam medesain bangunan

Chemical Biological Sensors Based on Advances in Conducting Electroactive Polymers

Advances in conducting electroactive polymers (CEPs) have driven the design of novel chemical and biochemical sensors. The redox properties of CEPs have been intensely studied for more than two decades with emphasis on their synthesis and characterization. Little attention has been paid to the importance of mechanism in sensor designs. However, in order to design robust and stable sensors, it is important to understand how the polymer structure, morphology, adhesion properties and microenvironment affect sensor performance. This work describes how chemical and biological sensors have been designed, fabricated, characterized and tested based on the fundamental understanding in CEPs. The use of photopolymerized conducting polymers in sensor designs is described. Four focus areas are presented in which the electronic properties of CEPs have enabled the design of novel sensors for organics, nucleic acids, biological molecules, vapors and metal ions