Electronic Properties of Strained Si/Ge Core-Shell Nanowires

We investigated the electronic properties of strained Si/Ge core-shell nanowires along the [110] direction using first principles calculations based on density-functional theory. The diameter of the studied core-shell wire is up to 5 nm. We found the band gap of the core-shell wire is smaller than that of both pure Si and Ge wires with the same diameter. This reduced band gap is ascribed to the intrinsic strain between Ge and Si layers, which partially counters the quantum confinement effect. The external strain is further applied to the nanowires for tuning the band structure and band gap. By applying sufficient tensile strain, we found the band gap of Si-core/Ge-shell nanowire with diameter larger than ~3 nm experiences a transition from direct to indirect gap.Comment: 4 figure

Optimal State Discrimination Using Particle Statistics

We present an application of particle statistics to the problem of optimal ambiguous discrimination of quantum states. The states to be discriminated are encoded in the internal degrees of freedom of identical particles, and we use the bunching and antibunching of the external degrees of freedom to discriminate between various internal states. We show that we can achieve the optimal single-shot discrimination probability using only the effects of particle statistics. We discuss interesting applications of our method to detecting entanglement and purifying mixed states. Our scheme can easily be implemented with the current technology

Employee attitudes as a mediator between HRM and organizational performance

Attitude is a power that controls human behaviour. When employee Attitude is positive, it can give impact positive to organization performance. A proper human resource management (HRM) managed by organization, the employee attitude will be affected. HRM practices influence employee attitude positively and there is a mediating role of employee attitude between training and development dimension of HRM practices and organizational performance. Therefore, the purpose of this study is to explore employee atttiude as a mediator between HRM and organizational performance. A sample of this study was 219 respondents from employee construction in Libya. The data was analyzed using structural equation modelling (SEM) approach. This study showed that employee attitudes is a full mediator between relationship HRM and organizational performance. Therefore, HRM practices influence employee attitude and its give impact to organizational performance for more effective and efficient in achieving organization goal

Recognizing Graph Theoretic Properties with Polynomial Ideals

Many hard combinatorial problems can be modeled by a system of polynomial equations. N. Alon coined the term polynomial method to describe the use of nonlinear polynomials when solving combinatorial problems. We continue the exploration of the polynomial method and show how the algorithmic theory of polynomial ideals can be used to detect k-colorability, unique Hamiltonicity, and automorphism rigidity of graphs. Our techniques are diverse and involve Nullstellensatz certificates, linear algebra over finite fields, Groebner bases, toric algebra, convex programming, and real algebraic geometry.Comment: 20 pages, 3 figure

Topical tacrolimus 0.1% ointment for treatment of cutaneous Crohn's Disease

Peer reviewedPublisher PD

Пилотное исследование эффективности использования фотодиодного сенсора в качестве дозиметра

Radiation dosimetry in the health and medicine field is crucial to ensure there is no unnecessary ionizing radiation exposure to patients and personnel. While various types of semiconductor dosimeters are available, photodiode sensors are seen as a reliable and cost-effective immediate dosimeter. This study investigates the capabilities of a monolithic photodiode with an on-chip trans-impedance amplifier as a dosimeter in diagnostic radiology. A photodiode sensor covered with black insulation tape is irradiated with the diagnostic x-ray of potential in range between 40 to 90 kV with constant tube current-time product of 50 mAs at 60 cm source-to-detector distance (SDD). Exposures of different tube current at the range of 10 to 250 mA with a constant tube voltage of 70 kVp at the same setup are made. The photodiode sensor connected to the electrometer gives out readings in the millivolt (mV), and the output of the photodiode and semiconductor detector is recorded. The photodiode’s energy dependency, reproducibility, dose response, and distance dependency were evaluated as the capabilities of the photodiode to be used as a dosimeter. For energy dependency, it shows a linearity of 0.9458, while the response to increasing tube current with a constant tube voltage shows the R2 of 0.912. The photodiode shows good dependency on the tube voltage and tube current. Other than that, it also showed a linear coefficient of 0.5138 for distance dependence which is considered as a good linearity fit value for a photodiode as initial performance. However, its reproducibility is poor due to its large capacitance. This monolithic photodiode with an on-chip trans-impedance amplifier has demonstrated good results for energy dependency but poor results for reproducibility. However, the photodiode can be improvised in the future to ensure it is suitable as a dosimeter.Дозиметрия излучения в области здравоохранения и медицины имеет решающее значение для предотвращения ненужного воздействия ионизирующего излучения на пациентов и персонал. Несмотря на доступность различных типов полупроводниковых дозиметров, фотодиодные датчики считаются надежными и экономичными непосредственными дозиметрами. В этом исследовании изучаются возможности использования монолитного фотодиода со встроенным трансимпедансным усилителем в качестве дозиметра в диагностической радиологии. Фотодиодный датчик, покрытый черной изоляционной лентой, облучался диагностическим рентгеновским излучением в диапазоне напряжений на излучателе от 40 до 90 кВ с постоянной экспозицией 50 мАс с расстояния в 60 см до детектора (SDD). На одной и той же установке производятся воздействия различного тока трубки в диапазоне от 10 до 250 мА с постоянным напряжением трубки 70 кВ. Фотодиодный датчик, подключенный к электрометру, выдает показания в милливольтах (мВ), а выходной сигнал фотодиода и полупроводникового детектора записывается. Энергетическая чувствительность фотодиода, воспроизводимость, реакция на дозу и зависимость от расстояния были оценены как возможности фотодиода для использования в качестве дозиметра. Для зависимости от энергии он показывает линейность 0,9458, в то время как для реакции на увеличение тока трубки при постоянном напряжении трубки R2 равен 0,912. Фотодиод показывает хорошую зависимость от напряжения лампы и тока трубки. Помимо этого, он также показал линейный коэффициент 0,5138 для зависимости от расстояния, который считается хорошим значением при линейной подгонке для фотодиода в качестве начальных характеристик. Однако его воспроизводимость недостаточно высока из-за большой емкости. Таким образом, изучаемый монолитный фотодиод со встроенным трансимпедансным усилителем показал хорошие результаты по энергетической зависимости, но низкие результаты по воспроизводимости. Тем не менее, в будущем фотодиод может быть усовершенствован, чтобы обеспечить его пригодность в качестве дозиметра

Antibody response to hepatitis b immunization in Egyptian children with sickle cell disease

Background: Despite improvement in the safety of blood products, sickle cell disease (SCD) and thalassemic patients are at greater risk than the general population for hepatitis B infection and chronic liver disease, making hepatitis B immunization especially important for this population. This study was conducted to evaluate and follow up the antibody response to hepatitis B vaccination, in patients with SCD, after 1-15 years of vaccination. Methods: participants were 30 SCD and 30 thalassemic patients attending the Hematology Department, Children’s Hospital, Cairo University as well as 30 ages and sex matched normal controls. They were subjected to clinical evaluation, complete blood count, and measurement of liver transaminases, serum bilirubin, and serum ferritin levels as well as estimation of anti-HBs titer by enzymatic immunoassay. Results: Anti-HBs titers in SCD patients ranged between 5.6 and 381 IU/L (54.83 ± 15.30), while the levels of thalassemic patients ranged between 16 and 343 IU/L (93.4 ± 30) and those of the control group ranged from 10 to 523 IU/L (83.4 ± 28.1) which revealed statistically significant decrease in SCD patients compared to thalassemic and healthy controls (p =0.0317). Out of the 30 SCD patients, 40% showed anti-HBs titer below 10 IU/L (non-protective titer), while none of the thalassemic patients or the control group revealed the same. Achievement of a protective titer had no correlation with sex, consanguinity, or any of the clinical or laboratory data tested. Conclusion: Immune dysfunction in thalassemia is not playing a major role in response to hepatitis B vaccination. However, SCD children should have their anti-HBs titer measured after routine hepatitis B immunization to ensure that they achieved protective titer, then after 1 year of vaccination and repeated every 5 years and those who do not seroconvert should receive additional doses. Booster HBV vaccination of unprotected SCD patients seems mandatory.Keywords: sickle cell, immunity, hepatitis B, immunizationEgypt J Pediatr Allergy Immunol 2010;8(2):67-7

Gaudin models solver based on the Bethe ansatz/ordinary differential equations correspondence

We present a numerical approach which allows the solving of Bethe equations whose solutions define the eigenstates of Gaudin models. By focusing on a new set of variables, the canceling divergences which occur for certain values of the coupling strength no longer appear explicitly. The problem is thus reduced to a set of quadratic algebraic equations. The required inverse transformation can then be realized using only linear operations and a standard polynomial root finding algorithm. The method is applied to Richardson's fermionic pairing model, the central spin model and generalized Dicke model.Comment: 10 pages, 3 figures, published versio