Mjerenje probojnih napona za više katodnih materijala u Townsendovom izboju

The breakdown potentials have been measured for argon and helium discharges using three different cathode materials: aluminium, silver and magnesium. The measurements show that lower breakdown potentials are associated with lower work function of the cathode material. For the three different cathodes, the secondary ionization coefficients have been estimated using the measured values of the breakdown potentials and the first ionization coefficient, in the range 0.60 to 2.25 V/[Pa cm] (80 to 300 V/[torr cm]) for Ar discharge and in the range of 0.15 to 1.80 V/[Pa cm] (20 to 240 V/[torr cm]) for He discharge. The minimum breakdown potential has been found at (pd)min = 80 Pa cm (0.6 torr cm) in Ar discharge and at 530 Pa cm (4.0 torr cm) in He discharge.Mjerili smo probojne potencijale za izboj u argonu i heliju s trima katodnim materijalima: aluminijem, srebrom i magnezijem. Mjerenja pokazuju da su niži probojni naponi povezani s nižim radnim funkcijama. Odredili smo sekundarne ionizacijske koeficijente za te tri vrste katoda na osnovi izmjerenih probojnih napona i prvih ionizacijskih koeficijenata, u području 0.60 to 2.25 V/[Pa cm] za izboj u Ar i u području 0.15 to 1.80 V/[Pa cm] za izboj u He. Najniži probojni napon za izboj u Ar iznosi (pd)min = 80 Pa cm, a za izboj u He 530 Pa cm (4.0 torr cm)

Thermal Equilibrium as an Initial State for Quantum Computation by NMR

We present a method of using a nuclear magnetic resonance computer to solve the Deutsch-Jozsa problem in which: (1) the number of molecules in the NMR sample is irrelevant to the number of qubits available to an NMR quantum computer, and (2) the initial state is chosen to be the state of thermal equilibrium, thereby avoiding the preparation of pseudopure states and the resulting exponential loss of signal as the number of qubits increases. The algorithm is described along with its experimental implementation using four active qubits. As expected, measured spectra demonstrate a clear distinction between constant and balanced functions.Comment: including 4 figure

A Modified Cooling System for Stand Alone PV Greenhouse in Remote Areas

Abstract. Agricultural efforts are normally carried out in remote areas where electricity from national electric grid may not exist or grid connection is very expensive. Greenhouses industry is one of the most important agricultural practices in remote areas. Greenhouses help in extending the gardening activities and allows us to cultivate certain plants all over the year; by controlling air temperature and relative humidity inside greenhouse. In greenhouses, cooling and pumping equipments dominate the demand for electricity. Therefore, a stand-alone photovoltaic (PV) system is necessary to feed that demand. Medicinal herbs, for example are the most suitable plants to be cultivated in the greenhouses. They often need a temperature range of 15 -21 oC and about 70% relative humidity to grow. As the climate in Egypt is not suitable all over the year to cultivate these medicinal herbs, it is preferable and necessary to use PV-based control greenhouse to cultivate these medicinal herbs in Egyptian remote areas. This paper presents a proposed greenhouse cooling system, which uses a stand-alone PV system to feed the electrical loads of the greenhouse. At the same time, it introduces the complete sizing procedure of the greenhouse stand-alone PV system

RT-PCR FOR ANTIOXIDANT GENES FROM EGYPTIAN GRAY MANGROVE Avicennia marina UNDER SALT STRESS TO NABQ PROTECTED AREA

RT-PCR was conducted for four genes implicated for salt tolerance, oxidative and osmotic stresses in Egyptian gray mangroves within Nabq protected area in South Sinai Governorate. The results showed over-expression of the mRNA of ferritin (amFer1) gene as very high expression, followed by increase in  mRNA of superoxide dismutase (amSOD1) and ubiquitin conjugation2 (amUBC2).  At the same time gene expression of catalase (amCAT1) decreased

Rapid solution of problems by nuclear-magnetic-resonance quantum computation

We offer an improved method for using a nuclear-magnetic-resonance quantum computer (NMRQC) to solve the Deutsch-Jozsa problem. Two known obstacles to the application of the NMRQC are exponential diminishment of density-matrix elements with the number of bits, threatening weak signal levels, and the high cost of preparing a suitable starting state. A third obstacle is a heretofore unnoticed restriction on measurement operators available for use by an NMRQC. Variations on the function classes of the Deutsch-Jozsa problem are introduced, both to extend the range of problems advantageous for quantum computation and to escape all three obstacles to use of an NMRQC. By adapting it to one such function class, the Deutsch-Jozsa problem is made solvable without exponential loss of signal. The method involves an extra work bit and a polynomially more involved Oracle; it uses the thermal-equilibrium density matrix systematically for an arbitrary number of spins, thereby avoiding both the preparation of a pseudopure state and temporal averaging.Comment: 19 page

IMPLEMENTATION OF HAZARD ANALYSIS CRITICAL CONTROL POINTS (HACCP) PRINCIPLES IN PRODUCTION OF FILLING CREAM

For improving the safety of filling cream, the Hazard Analysis Critical Control Points (HACCP) system was applied during different preparation process. Different biological, chemical, and physical hazards that may exist in every preparing step of filling cream were identified and control measures were used for controlling those identified hazards. Dried milk powder was identified as high potential hazard raw materials contaminated with pathogenic bacteria e.g. S. aureus and Salmonella sp. Whipping step in preparing filling cream was identified as critical control point. For improving the safety of preparing filling cream system, different control measures including, thermal processing (pasteurization), addition of natural preservatives (lemongrass oil and herbs of cinnamon, clove and anise) and reduction of pH (fruit pulps of strawberry, apricots and apple) were established. Different applied control measures could be used for improving the safety of prepared filling cream where different investigated microbiological criteria were reduced to acceptable levels especially pathogenic bacteria. In addition, different HACCP principles as the critical control points, critical limits, monitoring, corrective measures, verifications and records were established. Implementing the HACCP system during preparing filling cream can effectively ensure safety of this product and other food products contained filling cram especially bakeries