Synthesis and characterization of ammonium phosphate fertilizers with boron

The concentration of boron, an essential micronutrient for plants, presents a narrow range between deficiency and toxicity. In order to provide the boron requirement for plants, and to avoid toxicity problems, boron compounds are mixed with basic fertilizers. Sodium borate pentahydrate was used as a boron source. Ammonium orthophosphates fertilizers with boron were prepared by neutralizing phosphoric acid with ammonia and addition of variable amounts of sodium tetraborate pentahydrate to the reaction mixture at a NH3:H3PO4 molar ratio of 1.5. The fertilizers obtained with boron contents ranging from 0.05 to 1 % (w/w) were fully characterized by chemical analysis, thermal analysis, X-ray diffraction and infrared spectrophotometry. The studies showed that up to 500 °C, regardless of the boron content, no significant changes concerning thermal stability and nutritional properties occurred. Above 500 °C, an increase of thermal stability with an increase of the boron content was observed. X-Ray diffraction of a heat-treated sample containing 5 % (w/w) boron indicated the appearance of boron orthophosphate, BPO4, as a new crystalline phase, and the disappearance of the previous structures above 500 °C, which explains the increase in thermal stability

Calculations

The fringes of the velvet petals brush up against the timeless bone-white bark. Her slender hand trembles, naked as it is without the gleaming ring she had dreamt of so often. There were two roses. One stark and wilting with its fleeting beauty, covering up the gaping scar. It was left at the graveside. ~excerpt from poe

February 7th

Let the light inso that when I finallysee you,love will belust will befate. ~excerpt from poe

Gomer

Cattail breath hot on your breast,but you can’t shake the feelingof someone in the next room.He would know. ~excerpt from poe

Influence of Rice Husk Ash and Clay in Stabilization of Silty Soils Using Cement

Soil stabilization is needed to enhance the strength of the soil. One popular method of soil stabilization is using cement. Due to the environmental issue, it is a need to reduce the application of cement and/or to replace partially the cement with other environmental-friendly compounds. One of these compounds is rice husk ash (RSA), which is agricultural wastes. The objective of this paper is to study the influence of RSA and clay as partial replacement to cement in soil stabilization of silt soil with high plasticity (MH) using cement. The cement used was ordinary Portland cement, while the RHA was obtained by burning rice husk at temperature of 250°C. The MH soil is stabilized with 4% cement, 4% cement and 3% rice husk ash and 4% cement, 3 % RHA and 3 % clay. The various tests were conducted on the pure and stabilized soils. Results have indicated that application of 4% cement, 3 % RHA and 3 % clay as silt soil stabilization is more favorable in increasing soil strength and reducing brittle behaviour of soil

The natural history of secondary muscle-invasive bladder cancer

BACKGROUND: The management of patients with high-grade non muscle invasive bladder cancer (NMIBC) brings diagnostic and therapeutic challenges. In the current study, we sought to study the natural history of progression to "secondary" muscle-invasive bladder cancer (MIBC)-cancer that developed during follow up of patients presenting with non-muscle invasive bladder cancer (NMIBC). METHODS: Between 1998 and 2008, 760 patients were treated for bladder cancer. Primary MIBC (>=T2) tumors (present upon presentation) were diagnosed in 114 patients. All patients with high-grade NMIBC were treated with intravesical BCG. Mean follow-up was 44 months. RESULTS: Forty patients (6.1%) developed secondary MIBC after a mean period of 21 months from initial diagnosis of bladder cancer. The 2- and 5-year disease-specific survival rates were better for patients with secondary MIBC (90% and 56% compared to 69% and 42% for patients with primary disease, p=0.03). The Kaplan-Meier curves of the two groups were parallel but displaced by approximately 2 years. CONCLUSION: In the current series, MIBC progression occurred among initially presenting patients with NMIBC in 6.1%. In most patients, the initial diagnosis of NMIBC is correct and muscle invasion occurs after a mean period of about 2 years. This supports a non-radical approach in patients with high-grade T1, Ta or Tis. Meticulous follow-up with liberal biopsy of any suspicious lesion may provide early diagnosis of invasive disease

STUDY CONCERNING PERFORMANCES OF TWO TYPES OF PREHYDROLYZED POLYMER IN COMPARISON WITH ALUMINUM SULPHATE AS A COAGULANT FOR WASTE WATER

The main environmental problems of pulp and paper production are water consumption, pollutant fillings of effluents (biogenic and refractory organic compounds, suspended solids, colloids, toxic inorganic compounds). This industry is obliged to minimize its impacts on the aquatic environment and at the same time, due to huge water consumption, must adopt strategies for sustainable use of water resources, in the context of ensuring European requirements for integrated pollution prevention and control and implementation of the Framework Directive of water. The original experimental research refers to the improvement of the efficiency of conventional physicochemical treatment of residual effluents from the pulp and paper industry by using new prehydrolysed coagulation-flocculating agents. This stage is preliminary to the advanced effluent treatment stage, for its recirculation in the technological process. Correlating these structures with the efficiencies obtained in coagulation, it is noted that the low coagulant doses of PAC-1 and PAC-2 compared to SA, are due to the existence of more active polymeric species of Al₁₃⁷⁺ or Al₃₀¹⁸⁺, with higher load and molecular weight than in the case of aluminium monomeric species formed in the use of aluminium sulphate. There are high efficiencies for removing turbidity between 98-99% as well as organic loading of about 70% for the three coagulants studied (SA, PAC-1, PAC-2), but for the same efficiencies the doses of SA were double or even triple those required for PAC-1 and PAC-2

Environmental friendly electrochemical determination of aspirin from alkaline aqueous solution

The electrochemical determination of acetylsalicylic acid (ASA) on multi-walled carbon nanotube- epoxy composite electrode (MWCNTs-EP) in aqueous solution was investigated using electrochemical techniques, e.g. cyclic voltammetry (CV), differentialpulsed voltammetry (DPV) and square-wave voltammetry (SWV). SWV applying allowed to reach the best performance in relation with the sensitivity for ASA determination in alkaline medium